1 <!DOCTYPE html> 2 <head> 3 <title>Android 5.1 Compatibility Definition</title> 4 <link rel="stylesheet" type="text/css" href="/compatibility/android-cdd.css"/> 5 </head> 6 <body> 7 <h1>Android 5.1 Compatibility Definition</h1> 8 9 <h6>Table of Contents</h6> 10 11 <div id="toc"> 12 13 <div id="toc_left"> 14 15 <p class="toc_h1"><a href="#1_introduction">1. Introduction</a></p> 16 17 <p class="toc_h1"><a href="#2_device_types">2. Device Types</a></p> 18 19 <p class="toc_h2"><a href="#2_1_device_configurations">2.1 Device Configurations</a></p> 20 21 <p class="toc_h1"><a href="#3_software">3. Software</a></p> 22 23 <p class="toc_h2"><a href="#3_1_managed_api_compatibility">3.1. Managed API Compatibility</a></p> 24 25 <p class="toc_h2"><a href="#3_2_soft_api_compatibility">3.2. Soft API Compatibility</a></p> 26 27 <p class="toc_h3"><a href="#3_2_1_permissions">3.2.1. Permissions</a></p> 28 29 <p class="toc_h3"><a href="#3_2_2_build_parameters">3.2.2. Build Parameters</a></p> 30 31 <p class="toc_h3"><a href="#3_2_3_intent_compatibility">3.2.3. Intent Compatibility</a></p> 32 33 <p class="toc_h4"><a href="#3_2_3_1_core_application_intents">3.2.3.1. Core Application Intents</a></p> 34 35 <p class="toc_h4"><a href="#3_2_3_2_intent_overrides">3.2.3.2. Intent Overrides</a></p> 36 37 <p class="toc_h4"><a href="#3_2_3_3_intent_namespaces">3.2.3.3. Intent Namespaces</a></p> 38 39 <p class="toc_h4"><a href="#3_2_3_4_broadcast_intents">3.2.3.4. Broadcast Intents</a></p> 40 41 <p class="toc_h4"><a href="#3_2_3_5_default_app_settings">3.2.3.5. Default App Settings</a></p> 42 43 <p class="toc_h2"><a href="#3_3_native_api_compatibility">3.3. Native API Compatibility</a></p> 44 45 <p class="toc_h3"><a href="#3_3_1_application_binary_interfaces">3.3.1. Application Binary Interfaces</a></p> 46 47 <p class="toc_h3"><a href="#3_3_2_32-bit_arm_native_code_compatibility">3.3.2. 32-bit ARM Native Code Compatibility</a></p> 48 49 <p class="toc_h2"><a href="#3_4_web_compatibility">3.4. Web Compatibility</a></p> 50 51 <p class="toc_h3"><a href="#3_4_1_webview_compatibility">3.4.1. WebView Compatibility</a></p> 52 53 <p class="toc_h3"><a href="#3_4_2_browser_compatibility">3.4.2. Browser Compatibility</a></p> 54 55 <p class="toc_h2"><a href="#3_5_api_behavioral_compatibility">3.5. API Behavioral Compatibility</a></p> 56 57 <p class="toc_h2"><a href="#3_6_api_namespaces">3.6. API Namespaces</a></p> 58 59 <p class="toc_h2"><a href="#3_7_runtime_compatibility">3.7. Runtime Compatibility</a></p> 60 61 <p class="toc_h2"><a href="#3_8_user_interface_compatibility">3.8. User Interface Compatibility</a></p> 62 63 <p class="toc_h3"><a href="#3_8_1_launcher_home_screen">3.8.1. Launcher (Home Screen)</a></p> 64 65 <p class="toc_h3"><a href="#3_8_2_widgets">3.8.2. Widgets</a></p> 66 67 <p class="toc_h3"><a href="#3_8_3_notifications">3.8.3. Notifications</a></p> 68 69 <p class="toc_h3"><a href="#3_8_4_search">3.8.4. Search</a></p> 70 71 <p class="toc_h3"><a href="#3_8_5_toasts">3.8.5. Toasts</a></p> 72 73 <p class="toc_h3"><a href="#3_8_6_themes">3.8.6. Themes</a></p> 74 75 <p class="toc_h3"><a href="#3_8_7_live_wallpapers">3.8.7. Live Wallpapers</a></p> 76 77 <p class="toc_h3"><a href="#3_8_8_activity_switching">3.8.8. Activity Switching</a></p> 78 79 <p class="toc_h3"><a href="#3_8_9_input_management">3.8.9. Input Management</a></p> 80 81 <p class="toc_h3"><a href="#3_8_10_lock_screen_media_control">3.8.10. Lock Screen Media Control</a></p> 82 83 <p class="toc_h3"><a href="#3_8_11_dreams">3.8.11. Dreams</a></p> 84 85 <p class="toc_h3"><a href="#3_8_12_location">3.8.12. Location</a></p> 86 87 <p class="toc_h3"><a href="#3_8_13_unicode_and_font">3.8.13. Unicode and Font</a></p> 88 89 90 91 </div> 92 93 <div id="toc_right"><br> 94 95 96 97 <p class="toc_h2"><a href="#3_9_device_administration">3.9. Device Administration</a></p> 98 99 <p class="toc_h2"><a href="#3_10_accessibility">3.10. Accessibility</a></p> 100 101 <p class="toc_h2"><a href="#3_11_text-to-speech">3.11. Text-to-Speech</a></p> 102 103 <p class="toc_h2"><a href="#3_12_tv_input_framework">3.12. TV Input Framework</a></p> 104 105 <p class="toc_h1"><a href="#4_application_packaging_compatibility">4. Application Packaging Compatibility</a></p> 106 107 <p class="toc_h1"><a href="#5_multimedia_compatibility">5. Multimedia Compatibility</a></p> 108 109 <p class="toc_h2"><a href="#5_1_media_codecs">5.1. Media Codecs</a></p> 110 111 <p class="toc_h3"><a href="#5_1_1_audio_codecs">5.1.1. Audio Codecs</a></p> 112 113 <p class="toc_h3"><a href="#5_1_2_image_codecs">5.1.2. Image Codecs</a></p> 114 115 <p class="toc_h3"><a href="#5_1_3_video_codecs">5.1.3. Video Codecs</a></p> 116 117 <p class="toc_h2"><a href="#5_2_video_encoding">5.2. Video Encoding</a></p> 118 119 <p class="toc_h2"><a href="#5_3_video_decoding">5.3. Video Decoding</a></p> 120 121 <p class="toc_h2"><a href="#5_4_audio_recording">5.4. Audio Recording</a></p> 122 123 <p class="toc_h3"><a href="#5_4_1_raw_audio_capture">5.4.1. Raw Audio Capture</a></p> 124 125 <p class="toc_h3"><a href="#5_4_2_capture_for_voice_recognition">5.4.2. Capture for Voice Recognition</a></p> 126 127 <p class="toc_h3"><a href="#5_4_3_capture_for_rerouting_of_playback">5.4.3. Capture for Rerouting of Playback</a></p> 128 129 <p class="toc_h2"><a href="#5_5_audio_playback">5.5. Audio Playback</a></p> 130 131 <p class="toc_h3"><a href="#5_5_1_raw_audio_playback">5.5.1. Raw Audio Playback</a></p> 132 133 <p class="toc_h3"><a href="#5_5_2_audio_effects">5.5.2. Audio Effects</a></p> 134 135 <p class="toc_h3"><a href="#5_5_3_audio_output_volume">5.5.3. Audio Output Volume</a></p> 136 137 <p class="toc_h2"><a href="#5_6_audio_latency">5.6. Audio Latency</a></p> 138 139 <p class="toc_h2"><a href="#5_7_network_protocols">5.7. Network Protocols</a></p> 140 141 <p class="toc_h2"><a href="#5_8_secure_media">5.8. Secure Media</a></p> 142 143 <p class="toc_h1"><a href="#6_developer_tools_and_options_compatibility">6. Developer Tools and Options Compatibility</a></p> 144 145 <p class="toc_h2"><a href="#6_1_developer_tools">6.1. Developer Tools</a></p> 146 147 <p class="toc_h2"><a href="#6_2_developer_options">6.2. Developer Options</a></p> 148 149 <p class="toc_h1"><a href="#7_hardware_compatibility">7. Hardware Compatibility</a></p> 150 151 <p class="toc_h2"><a href="#7_1_display_and_graphics">7.1. Display and Graphics</a></p> 152 153 <p class="toc_h3"><a href="#7_1_1_screen_configuration">7.1.1. Screen Configuration</a></p> 154 155 <p class="toc_h4"><a href="#7_1_1_1_screen_size">7.1.1.1. Screen Size</a></p> 156 157 <p class="toc_h4"><a href="#7_1_1_2_screen_aspect_ratio">7.1.1.2. Screen Aspect Ratio</a></p> 158 159 <p class="toc_h4"><a href="#7_1_1_3_screen_density">7.1.1.3. Screen Density</a></p> 160 161 162 </div> 163 164 <div style="clear: both; page-break-after:always; height:1px"></div> 165 166 167 <div id="toc_left_2"> 168 169 <p class="toc_h3"><a href="#7_1_2_display_metrics">7.1.2. Display Metrics</a></p> 170 171 <p class="toc_h3"><a href="#7_1_3_screen_orientation">7.1.3. Screen Orientation</a></p> 172 173 <p class="toc_h3"><a href="#7_1_4_2d_and_3d_graphics_acceleration">7.1.4. 2D and 3D Graphics Acceleration</a></p> 174 175 <p class="toc_h3"><a href="#7_1_5_legacy_application_compatibility_mode">7.1.5. Legacy Application Compatibility Mode</a></p> 176 177 <p class="toc_h3"><a href="#7_1_6_screen_technology">7.1.6. Screen Technology</a></p> 178 179 <p class="toc_h3"><a href="#7_1_7_external_displays">7.1.7. Secondary Displays</a></p> 180 181 <p class="toc_h2"><a href="#7_2_input_devices">7.2. Input Devices</a></p> 182 183 <p class="toc_h3"><a href="#7_2_1_keyboard">7.2.1. Keyboard</a></p> 184 185 <p class="toc_h3"><a href="#7_2_2_non-touch_navigation">7.2.2. Non-touch Navigation</a></p> 186 187 <p class="toc_h3"><a href="#7_2_3_navigation_keys">7.2.3. Navigation Keys</a></p> 188 189 <p class="toc_h3"><a href="#7_2_4_touchscreen_input">7.2.4. Touchscreen Input</a></p> 190 191 <p class="toc_h3"><a href="#7_2_5_fake_touch_input">7.2.5. Fake Touch Input</a></p> 192 193 <p class="toc_h3"><a href="#7_2_6_game_controller_support">7.2.6. Game Controller Support</a></p> 194 195 <p class="toc_h4"><a href="#7_2_6_1_button_mapping">7.2.6.1. Button Mappings</a></p> 196 197 <p class="toc_h3"><a href="#7_2_7_remote_control">7.2.7. Remote Control</a></p> 198 199 <p class="toc_h2"><a href="#7_3_sensors">7.3. Sensors</a></p> 200 201 <p class="toc_h3"><a href="#7_3_1_accelerometer">7.3.1. Accelerometer</a></p> 202 203 <p class="toc_h3"><a href="#7_3_2_magnetometer">7.3.2. Magnetometer</a></p> 204 205 <p class="toc_h3"><a href="#7_3_3_gps">7.3.3. GPS</a></p> 206 207 <p class="toc_h3"><a href="#7_3_4_gyroscope">7.3.4. Gyroscope</a></p> 208 209 <p class="toc_h3"><a href="#7_3_5_barometer">7.3.5. Barometer</a></p> 210 211 <p class="toc_h3"><a href="#7_3_6_thermometer">7.3.6. Thermometer</a></p> 212 213 <p class="toc_h3"><a href="#7_3_7_photometer">7.3.7. Photometer</a></p> 214 215 <p class="toc_h3"><a href="#7_3_8_proximity_sensor">7.3.8. Proximity Sensor</a></p> 216 217 <p class="toc_h2"><a href="#7_4_data_connectivity">7.4. Data Connectivity</a></p> 218 219 <p class="toc_h3"><a href="#7_4_1_telephony">7.4.1. Telephony</a></p> 220 221 <p class="toc_h3"><a href="#7_4_2_ieee_80211_wi-fi">7.4.2. IEEE 802.11 (Wi-Fi)</a></p> 222 223 <p class="toc_h4"><a href="#7_4_2_1_wi-fi_direct">7.4.2.1. Wi-Fi Direct</a></p> 224 225 <p class="toc_h4"><a href="#7_4_2_2_wi-fi-tunneled-direct-link-setup">7.4.2.2. Wi-Fi Tunneled Direct Link Setup</a></p> 226 227 <p class="toc_h3"><a href="#7_4_3_bluetooth">7.4.3. Bluetooth</a></p> 228 229 <p class="toc_h3"><a href="#7_4_4_near-field_communications">7.4.4. Near-Field Communications</a></p> 230 231 <p class="toc_h3"><a href="#7_4_5_minimum_network_capability">7.4.5. Minimum Network Capability</a></p> 232 233 <p class="toc_h3"><a href="#7_4_6_sync_settings">7.4.6. Sync Settings</a></p> 234 235 <p class="toc_h2"><a href="#7_5_cameras">7.5. Cameras</a></p> 236 237 <p class="toc_h3"><a href="#7_5_1_rear-facing_camera">7.5.1. Rear-Facing Camera</a></p> 238 239 <p class="toc_h3"><a href="#7_5_2_front-facing_camera">7.5.2. Front-Facing Camera</a></p> 240 241 <p class="toc_h3"><a href="#7_5_3_external_camera">7.5.3. External Camera</a></p> 242 243 <p class="toc_h3"><a href="#7_5_4_camera_api_behavior">7.5.4. Camera API Behavior</a></p> 244 245 246 247 248 249 </div> 250 251 <div id="toc_right_2"> 252 253 <p class="toc_h3"><a href="#7_5_5_camera_orientation">7.5.5. Camera Orientation</a></p> 254 255 <p class="toc_h2"><a href="#7_6_memory_and_storage">7.6. Memory and Storage</a></p> 256 257 <p class="toc_h3"><a href="#7_6_1_minimum_memory_and_storage">7.6.1. Minimum Memory and Storage</a></p> 258 259 <p class="toc_h3"><a href="#7_6_2_application_shared_storage">7.6.2. Application Shared Storage</a></p> 260 261 <p class="toc_h2"><a href="#7_7_usb">7.7. USB</a></p> 262 263 <p class="toc_h2"><a href="#7_8_audio">7.8. Audio</a></p> 264 265 <p class="toc_h3"><a href="#7_8_1_microphone">7.8.1. Microphone</a></p> 266 267 <p class="toc_h3"><a href="#7_8_2_audio_output">7.8.2. Audio Output</a></p> 268 269 <p class="toc_h4"><a href="#7_8_2_1_analog_audio_ports">7.8.2.1. Analog Audio Ports</a></p> 270 271 <p class="toc_h1"><a href="#8_performance_compatibility">8. Performance Compatibility</a></p> 272 273 <p class="toc_h2"><a href="#8_1_user_experience_consistency">8.1. User Experience Consistency</a></p> 274 275 <p class="toc_h2"><a href="#8_2_memory_performance">8.2. Memory Performance</a></p> 276 277 <p class="toc_h1"><a href="#9_security_model_compatibility">9. Security Model Compatibility</a></p> 278 279 <p class="toc_h2"><a href="#9_1_permissions">9.1. Permissions</a></p> 280 281 <p class="toc_h2"><a href="#9_2_uid_and_process_isolation">9.2. UID and Process Isolation</a></p> 282 283 <p class="toc_h2"><a href="#9_3_filesystem_permissions">9.3. Filesystem Permissions</a></p> 284 285 <p class="toc_h2"><a href="#9_4_alternate_execution_environments">9.4. Alternate Execution Environments</a></p> 286 287 <p class="toc_h2"><a href="#9_5_multi-user_support">9.5. Multi-User Support</a></p> 288 289 <p class="toc_h2"><a href="#9_6_premium_sms_warning">9.6. Premium SMS Warning</a></p> 290 291 <p class="toc_h2"><a href="#9_7_kernel_security_features">9.7. Kernel Security Features</a></p> 292 293 <p class="toc_h2"><a href="#9_8_privacy">9.8. Privacy</a></p> 294 295 <p class="toc_h2"><a href="#9_9_full-disk-encryption">9.9. Full-Disk Encryption</a></p> 296 297 <p class="toc_h2"><a href="#9_10_verified_boot">9.10. Verified Boot</a></p> 298 299 <p class="toc_h1"><a href="#10_software_compatibility_testing">10. Software Compatibility Testing</a></p> 300 301 <p class="toc_h2"><a href="#10_1_compatibility_test_suite">10.1. Compatibility Test Suite</a></p> 302 303 <p class="toc_h2"><a href="#10_2_cts_verifier">10.2. CTS Verifier</a></p> 304 305 <p class="toc_h1"><a href="#11_updatable_software">11. Updatable Software</a></p> 306 307 <p class="toc_h1"><a href="#12_document_changelog">12. Document Changelog</a></p> 308 309 <p class="toc_h1"><a href="#13_contact_us">13. Contact Us</a></p> 310 311 <p class="toc_h1"><a href="#14_resources">14. Resources</a></p> 312 313 </div> 314 315 </div> 316 317 <div style="clear: both"></div> 318 319 <div id="main"> 320 321 <h1 id="1_introduction">1. Introduction</h1> 322 323 324 <p>This document enumerates the requirements that must be met in order for devices 325 to be compatible with Android 5.1.</p> 326 327 <p>The use of “MUST”, “MUST NOT”, “REQUIRED”, “SHALL”, “SHALL NOT”, “SHOULD”,“SHOULD NOT”, “RECOMMENDED”, “MAY”, and “OPTIONAL” is per the IETF standard 328 defined in RFC2119 [<a href="http://www.ietf.org/rfc/rfc2119.txt">Resources, 1</a>].</p> 329 330 <p>As used in this document, a “device implementer” or “implementer” is a person 331 or organization developing a hardware/software solution running Android 5.1. A 332 “device implementation” or “implementation is the hardware/software solution 333 so developed.</p> 334 335 <p>To be considered compatible with Android 5.1, device implementations MUST meet 336 the requirements presented in this Compatibility Definition, including any 337 documents incorporated via reference.</p> 338 339 <p>Where this definition or the software tests described in <a href="#10_software_compatibility_testing">section 10</a> is silent, ambiguous, or incomplete, it is the responsibility of the device 340 implementer to ensure compatibility with existing implementations.</p> 341 342 <p>For this reason, the Android Open Source Project [<a href="http://source.android.com/">Resources, 2</a>] is both the reference and preferred implementation of Android. Device 343 implementers are strongly encouraged to base their implementations to the 344 greatest extent possible on the “upstream” source code available from the 345 Android Open Source Project. While some components can hypothetically be 346 replaced with alternate implementations this practice is strongly discouraged, 347 as passing the software tests will become substantially more difficult. It is 348 the implementer’s responsibility to ensure full behavioral compatibility with 349 the standard Android implementation, including and beyond the Compatibility 350 Test Suite. Finally, note that certain component substitutions and 351 modifications are explicitly forbidden by this document.</p> 352 353 <p>Many of the resources listed in <a href="#14_resources">section 14</a> are derived directly or indirectly from the Android SDK, and will be 354 functionally identical to the information in that SDK’s documentation. For any 355 case where this Compatibility Definition or the Compatibility Test Suite 356 disagrees with the SDK documentation, the SDK documentation is considered 357 authoritative. Any technical details provided in the references included in <a href="#14_resources">section 14</a> are considered by inclusion to be part of this Compatibility Definition. </p> 358 359 <h1 id="2_device_types">2. Device Types</h1> 360 361 362 <p>While the Android Open Source Project has been used in the implementation of a 363 variety of device types and form factors, many aspects of the architecture and 364 compatibility requirements were optimized for handheld devices. Starting from 365 Android 5.0, the Android Open Source Project aims to embrace a wider variety of 366 device types as described in this section.</p> 367 368 <p><strong>Android Handheld device</strong> refers to an Android device implementation that is typically used by holding 369 it in the hand, such as mp3 players, phones, and tablets. Android Handheld 370 device implementations:</p> 371 372 <ul> 373 <li>MUST have a touchscreen embedded in the device.</li> 374 <li>MUST have a power source that provides mobility, such as a battery.</li> 375 </ul> 376 377 <p><strong>Android Television device</strong> refers to an Android device implementation that is an entertainment interface 378 for consuming digital media, movies, games, apps, and/or live TV for users 379 sitting about ten feet away (a “lean back” or “10-foot user interface”). 380 Android Television devices:</p> 381 382 <ul> 383 <li>MUST have an embedded screen OR include a video output port, such as VGA, HDMI, 384 or a wireless port for display.</li> 385 <li>MUST declare the features android.software.leanback and 386 android.hardware.type.television [<a href="http://developer.android.com/reference/android/content/pm/PackageManager.html#FEATURE_LEANBACK">Resources, 3</a>].</li> 387 </ul> 388 389 <p><strong>Android Watch device</strong> refers to an Android device implementation intended to be worn on the body, 390 perhaps on the wrist, and:</p> 391 392 <ul> 393 <li>MUST have a screen with the physical diagonal length in the range from 1.1 to 394 2.5 inches.</li> 395 <li>MUST declare the feature android.hardware.type.watch.</li> 396 <li>MUST support uiMode = UI_MODE_TYPE_WATCH [<a href="http://developer.android.com/reference/android/content/res/Configuration.html#UI_MODE_TYPE_WATCH">Resources, 4</a>].</li> 397 </ul> 398 399 <p><strong>Android Automotive implementation</strong> refers to a vehicle head 400 unit running Android as an operating system for part or all of the system and/or 401 infotainment functionality. Android Automotive implementations MUST support 402 uiMode = UI_MODE_TYPE_CAR [<a href="http://developer.android.com/reference/android/content/res/Configuration.html#UI_MODE_TYPE_CAR">Resources, 111</a>].</p> 403 404 <p>All Android device implementations that do not fit into any of the above device 405 types still MUST meet all requirements in this document to be Android 5.1 406 compatible, unless the requirement is explicitly described to be only 407 applicable to a specific Android device type from above.</p> 408 409 <h2 id="2_1_device_configurations">2.1 Device Configurations</h2> 410 411 412 <p>This is a summary of major differences in hardware configuration by device 413 type. (Empty cells denote a “MAY”). Not all configurations are covered in this 414 table; see relevant hardware sections for more detail.</p> 415 <table> 416 <tr> 417 <th>Category</th> 418 <th>Feature</th> 419 <th>Section</th> 420 <th>Handheld</th> 421 <th>Television</th> 422 <th>Watch</th> 423 <th>Automotive</th> 424 <th>Other</th> 425 </tr> 426 <tr> 427 <td rowspan="3">Input</td> 428 <td>D-pad</td> 429 <td><a href="#7_2_2_non-touch-navigation">7.2.2. Non-touch Navigation</a></td> 430 <td></td> 431 <td>MUST</td> 432 <td></td> 433 <td></td> 434 <td></td> 435 </tr> 436 <tr> 437 <td>Touchscreen </td> 438 <td><a href="#7_2_4_touchscreen_input">7.2.4. Touchscreen input</a></td> 439 <td>MUST</td> 440 <td></td> 441 <td>MUST</td> 442 <td></td> 443 <td>SHOULD</td> 444 </tr> 445 <tr> 446 <td>Microphone </td> 447 <td><a href="#7_8_1_microphone">7.8.1. Microphone</a></td> 448 <td>MUST</td> 449 <td>SHOULD </td> 450 <td>MUST</td> 451 <td>MUST</td> 452 <td>SHOULD</td> 453 </tr> 454 <tr> 455 <td rowspan="2">Sensors</td> 456 <td>Accelerometer </td> 457 <td><a href="#7_3_1_accelerometer">7.3.1 Accelerometer</a></td> 458 <td>SHOULD</td> 459 <td></td> 460 <td>SHOULD</td> 461 <td></td> 462 <td>SHOULD</td> 463 </tr> 464 <tr> 465 <td>GPS</td> 466 <td><a href="#7_3_3_gps">7.3.3. GPS</a></td> 467 <td>SHOULD</td> 468 <td></td> 469 <td></td> 470 <td>SHOULD</td> 471 <td></td> 472 </tr> 473 <tr> 474 <td rowspan="5">Connectivity</td> 475 <td>Wi-Fi</td> 476 <td><a href="#7_4_2_ieee_802.11">7.4.2. IEEE 802.11</a></td> 477 <td>SHOULD</td> 478 <td> MUST</td> 479 <td></td> 480 <td>SHOULD</td> 481 <td>SHOULD</td> 482 </tr> 483 <tr> 484 <td>Wi-Fi Direct</td> 485 <td><a href="#7_4_2_1_wi-fi-direct">7.4.2.1. Wi-Fi Direct</a></td> 486 <td>SHOULD</td> 487 <td>SHOULD</td> 488 <td></td> 489 <td></td> 490 <td>SHOULD</td> 491 </tr> 492 <tr> 493 <td>Bluetooth</td> 494 <td><a href="#7_4_3_bluetooth">7.4.3. Bluetooth</a></td> 495 <td>SHOULD</td> 496 <td>MUST</td> 497 <td>MUST</td> 498 <td>MUST</td> 499 <td>SHOULD</td> 500 </tr> 501 <tr> 502 <td>Bluetooth Low Energy</td> 503 <td><a href="#7_4_3_bluetooth">7.4.3. Bluetooth</a></td> 504 <td>SHOULD</td> 505 <td>MUST</td> 506 <td>SHOULD</td> 507 <td>SHOULD</td> 508 <td>SHOULD</td> 509 </tr> 510 <tr> 511 <td>USB peripheral/host mode</td> 512 <td><a href="#7_7_usb">7.7. USB</a></td> 513 <td>SHOULD</td> 514 <td></td> 515 <td></td> 516 <td>SHOULD</td> 517 <td>SHOULD</td> 518 </tr> 519 <tr> 520 <td>Output</td> 521 <td>Speaker and/or Audio output ports</td> 522 <td><a href="#7_8_2_audio_output">7.8.2. Audio Output</a></td> 523 <td>MUST</td> 524 <td>MUST</td> 525 <td></td> 526 <td>MUST</td> 527 <td>MUST</td> 528 </tr> 529 </table> 530 531 532 <h1 id="3_software">3. Software</h1> 533 534 535 <h2 id="3_1_managed_api_compatibility">3.1. Managed API Compatibility</h2> 536 537 538 <p>The managed Dalvik bytecode execution environment is the primary vehicle for 539 Android applications. The Android application programming interface (API) is 540 the set of Android platform interfaces exposed to applications running in the 541 managed runtime environment. Device implementations MUST provide complete 542 implementations, including all documented behaviors, of any documented API 543 exposed by the Android SDK [<a href="http://developer.android.com/reference/packages.html">Resources, 5</a>] or any API decorated with the “@SystemApi” marker in the upstream Android 544 source code. </p> 545 546 <p>Device implementations MUST NOT omit any managed APIs, alter API interfaces or 547 signatures, deviate from the documented behavior, or include no-ops, except 548 where specifically allowed by this Compatibility Definition.</p> 549 550 <p>This Compatibility Definition permits some types of hardware for which Android 551 includes APIs to be omitted by device implementations. In such cases, the APIs 552 MUST still be present and behave in a reasonable way. See <a href="#7_hardware_compatibility">section 7</a> for specific requirements for this scenario.</p> 553 554 <h2 id="3_2_soft_api_compatibility">3.2. Soft API Compatibility</h2> 555 556 557 <p>In addition to the managed APIs from <a href="#3_1_managed_api_compatibility">section 3.1</a>, Android also includes a significant runtime-only “soft” API, in the form of 558 such things as intents, permissions, and similar aspects of Android 559 applications that cannot be enforced at application compile time.</p> 560 561 <h3 id="3_2_1_permissions">3.2.1. Permissions</h3> 562 563 564 <p>Device implementers MUST support and enforce all permission constants as 565 documented by the Permission reference page [<a href="http://developer.android.com/reference/android/Manifest.permission.html">Resources, 6]</a>. Note that <a href="#9_security_model_compatibility">section 9</a> lists additional requirements related to the Android security model.</p> 566 567 <h3 id="3_2_2_build_parameters">3.2.2. Build Parameters</h3> 568 569 570 <p>The Android APIs include a number of constants on the android.os.Build class [<a href="http://developer.android.com/reference/android/os/Build.html">Resources, 7</a>] that are intended to describe the current device. To provide consistent, 571 meaningful values across device implementations, the table below includes 572 additional restrictions on the formats of these values to which device 573 implementations MUST conform.</p> 574 <table> 575 <tr> 576 <th>Parameter</th> 577 <th>Details</th> 578 </tr> 579 <tr> 580 <td>VERSION.RELEASE</td> 581 <td>The version of the currently-executing Android system, in human-readable 582 format. This field MUST have one of the string values defined in [<a href="http://source.android.com/compatibility/5.1/versions.html">Resources, 8]</a>.</td> 583 </tr> 584 <tr> 585 <td>VERSION.SDK</td> 586 <td>The version of the currently-executing Android system, in a format accessible 587 to third-party application code. For Android 5.1, this field MUST have the 588 integer value 22.</td> 589 </tr> 590 <tr> 591 <td>VERSION.SDK_INT</td> 592 <td>The version of the currently-executing Android system, in a format accessible 593 to third-party application code. For Android 5.1, this field MUST have the 594 integer value 22.</td> 595 </tr> 596 <tr> 597 <td>VERSION.INCREMENTAL</td> 598 <td>A value chosen by the device implementer designating the specific build of the 599 currently-executing Android system, in human-readable format. This value MUST 600 NOT be reused for different builds made available to end users. A typical use 601 of this field is to indicate which build number or source-control change 602 identifier was used to generate the build. There are no requirements on the 603 specific format of this field, except that it MUST NOT be null or the empty 604 string ("").</td> 605 </tr> 606 <tr> 607 <td>BOARD</td> 608 <td>A value chosen by the device implementer identifying the specific internal 609 hardware used by the device, in human-readable format. A possible use of this 610 field is to indicate the specific revision of the board powering the device. 611 The value of this field MUST be encodable as 7-bit ASCII and match the regular 612 expression “^[a-zA-Z0-9_-]+$”.</td> 613 </tr> 614 <tr> 615 <td>BRAND</td> 616 <td>A value reflecting the brand name associated with the device as known to the 617 end users. MUST be in human-readable format and SHOULD represent the 618 manufacturer of the device or the company brand under which the device is 619 marketed. The value of this field MUST be encodable as 7-bit ASCII and match 620 the regular expression “^[a-zA-Z0-9_-]+$”.</td> 621 </tr> 622 <tr> 623 <td>SUPPORTED_ABIS</td> 624 <td>The name of the instruction set (CPU type + ABI convention) of native code. See <a href="#3_3_native_api_compatibility">section 3.3. Native API Compatibility</a>.</td> 625 </tr> 626 <tr> 627 <td>SUPPORTED_32_BIT_ABIS</td> 628 <td>The name of the instruction set (CPU type + ABI convention) of native code. See <a href="#3_3_native_api_compatibility">section 3.3. Native API Compatibility</a>.</td> 629 </tr> 630 <tr> 631 <td>SUPPORTED_64_BIT_ABIS</td> 632 <td>The name of the second instruction set (CPU type + ABI convention) of native 633 code. See <a href="#3_3_native_api_compatibility">section 3.3. Native API Compatibility</a>.</td> 634 </tr> 635 <tr> 636 <td>CPU_ABI</td> 637 <td>The name of the instruction set (CPU type + ABI convention) of native code. See <a href="#3_3_native_api_compatibility">section 3.3. Native API Compatibility</a>.</td> 638 </tr> 639 <tr> 640 <td>CPU_ABI2</td> 641 <td>The name of the second instruction set (CPU type + ABI convention) of native 642 code. See <a href="#3_3_native_api_compatibility">section 3.3. Native API Compatibility</a>.</td> 643 </tr> 644 <tr> 645 <td>DEVICE</td> 646 <td>A value chosen by the device implementer containing the development name or 647 code name identifying the configuration of the hardware features and industrial 648 design of the device. The value of this field MUST be encodable as 7-bit ASCII 649 and match the regular expression “^[a-zA-Z0-9_-]+$”.</td> 650 </tr> 651 <tr> 652 <td>FINGERPRINT</td> 653 <td>A string that uniquely identifies this build. It SHOULD be reasonably 654 human-readable. It MUST follow this template:</p> 655 656 <p class="small">$(BRAND)/$(PRODUCT)/$(DEVICE):$(VERSION.RELEASE)/$(ID)/$(VERSION.INCREMENTAL):$(TYPE)/$(TAGS)</p> 657 658 <p>For example: acme/myproduct/mydevice:5.1/LMYXX/3359:userdebug/test-keys</p> 659 660 <p>The fingerprint MUST NOT include whitespace characters. If other fields 661 included in the template above have whitespace characters, they MUST be 662 replaced in the build fingerprint with another character, such as the 663 underscore ("_") character. The value of this field MUST be encodable as 7-bit 664 ASCII.</td> 665 </tr> 666 <tr> 667 <td>HARDWARE</td> 668 <td>The name of the hardware (from the kernel command line or /proc). It SHOULD be 669 reasonably human-readable. The value of this field MUST be encodable as 7-bit 670 ASCII and match the regular expression “^[a-zA-Z0-9_-]+$”. </td> 671 </tr> 672 <tr> 673 <td>HOST</td> 674 <td>A string that uniquely identifies the host the build was built on, in 675 human-readable format. There are no requirements on the specific format of this 676 field, except that it MUST NOT be null or the empty string ("").</td> 677 </tr> 678 <tr> 679 <td>ID</td> 680 <td>An identifier chosen by the device implementer to refer to a specific release, 681 in human-readable format. This field can be the same as 682 android.os.Build.VERSION.INCREMENTAL, but SHOULD be a value sufficiently 683 meaningful for end users to distinguish between software builds. The value of 684 this field MUST be encodable as 7-bit ASCII and match the regular expression “^[a-zA-Z0-9._-]+$”.</td> 685 </tr> 686 <tr> 687 <td>MANUFACTURER</td> 688 <td>The trade name of the Original Equipment Manufacturer (OEM) of the product. 689 There are no requirements on the specific format of this field, except that it 690 MUST NOT be null or the empty string ("").</td> 691 </tr> 692 <tr> 693 <td>MODEL</td> 694 <td>A value chosen by the device implementer containing the name of the device as 695 known to the end user. This SHOULD be the same name under which the device is 696 marketed and sold to end users. There are no requirements on the specific 697 format of this field, except that it MUST NOT be null or the empty string ("").</td> 698 </tr> 699 <tr> 700 <td>PRODUCT</td> 701 <td>A value chosen by the device implementer containing the development name or 702 code name of the specific product (SKU) that MUST be unique within the same 703 brand. MUST be human-readable, but is not necessarily intended for view by end 704 users. The value of this field MUST be encodable as 7-bit ASCII and match the 705 regular expression “^[a-zA-Z0-9_-]+$”.</td> 706 </tr> 707 <tr> 708 <td>SERIAL</td> 709 <td>A hardware serial number, which MUST be available. The value of this field MUST 710 be encodable as 7-bit ASCII and match the regular expression “^([a-zA-Z0-9]{6,20})$”.</td> 711 </tr> 712 <tr> 713 <td>TAGS</td> 714 <td>A comma-separated list of tags chosen by the device implementer that further 715 distinguishes the build. This field MUST have one of the values corresponding 716 to the three typical Android platform signing configurations: release-keys, 717 dev-keys, test-keys. </td> 718 </tr> 719 <tr> 720 <td>TIME</td> 721 <td>A value representing the timestamp of when the build occurred.</td> 722 </tr> 723 <tr> 724 <td>TYPE</td> 725 <td>A value chosen by the device implementer specifying the runtime configuration 726 of the build. This field MUST have one of the values corresponding to the three 727 typical Android runtime configurations: user, userdebug, or eng.</td> 728 </tr> 729 <tr> 730 <td>USER</td> 731 <td>A name or user ID of the user (or automated user) that generated the build. 732 There are no requirements on the specific format of this field, except that it 733 MUST NOT be null or the empty string ("").</td> 734 </tr> 735 </table> 736 737 738 <h3 id="3_2_3_intent_compatibility">3.2.3. Intent Compatibility</h3> 739 740 741 <p>Device implementations MUST honor Android’s loose-coupling intent system, as 742 described in the sections below. By“honored ” it is meant that the device 743 implementer MUST provide an Android Activity or Service that specifies a 744 matching intent filter that binds to and implements correct behavior for each 745 specified intent pattern.</p> 746 747 <h4 id="3_2_3_1_core_application_intents">3.2.3.1. Core Application Intents</h4> 748 749 750 <p>Android intents allow application components to request functionality from 751 other Android components. The Android upstream project includes a list of 752 applications considered core Android applications, which implements several 753 intent patterns to perform common actions. The core Android applications are:</p> 754 755 <ul> 756 <li>Desk Clock</li> 757 <li>Browser</li> 758 <li>Calendar</li> 759 <li>Contacts</li> 760 <li>Gallery</li> 761 <li>GlobalSearch</li> 762 <li>Launcher</li> 763 <li>Music</li> 764 <li>Settings</li> 765 </ul> 766 767 <p>Device implementations SHOULD include the core Android applications as 768 appropriate but MUST include a component implementing the same intent patterns 769 defined by all the “public” Activity or Service components of these core 770 Android applications. Note that Activity or Service components are considered 771 “public” when the attribute android:exported is absent or has the value true.</p> 772 773 <h4 id="3_2_3_2_intent_overrides">3.2.3.2. Intent Overrides</h4> 774 775 776 <p>As Android is an extensible platform, device implementations MUST allow each 777 intent pattern referenced in <a href="#3_2_3_1_core_application_intents">section 3.2.3.1</a> to be overridden by third-party applications. The upstream Android open source 778 implementation allows this by default; device implementers MUST NOT attach 779 special privileges to system applications' use of these intent patterns, or 780 prevent third-party applications from binding to and assuming control of these 781 patterns. This prohibition specifically includes but is not limited to 782 disabling the“Chooser” user interface that allows the user to select between 783 multiple applications that all handle the same intent pattern.</p> 784 785 <p>However, device implementations MAY provide default activities for specific URI 786 patterns (eg. http://play.google.com) if the default activity provides a more 787 specific filter for the data URI. For example, an intent filter specifying the 788 data URI “http://www.android.com” is more specific than the browser filter for“http://”. Device implementations MUST provide a user interface for users to 789 modify the default activity for intents.</p> 790 791 <h4 id="3_2_3_3_intent_namespaces">3.2.3.3. Intent Namespaces</h4> 792 793 794 <p>Device implementations MUST NOT include any Android component that honors any 795 new intent or broadcast intent patterns using an ACTION, CATEGORY, or other key 796 string in the android.* or com.android.* namespace. Device implementers MUST 797 NOT include any Android components that honor any new intent or broadcast 798 intent patterns using an ACTION, CATEGORY, or other key string in a package 799 space belonging to another organization. Device implementers MUST NOT alter or 800 extend any of the intent patterns used by the core apps listed in <a href="#3_2_3_1_core_application_intents">section 3.2.3.1</a>. Device implementations MAY include intent patterns using namespaces clearly 801 and obviously associated with their own organization. This prohibition is 802 analogous to that specified for Java language classes in <a href="#3_6_api_namespaces">section 3.6</a>.</p> 803 804 <h4 id="3_2_3_4_broadcast_intents">3.2.3.4. Broadcast Intents</h4> 805 806 807 <p>Third-party applications rely on the platform to broadcast certain intents to 808 notify them of changes in the hardware or software environment. 809 Android-compatible devices MUST broadcast the public broadcast intents in 810 response to appropriate system events. Broadcast intents are described in the 811 SDK documentation.</p> 812 813 <h4 id="3_2_3_5_default_app_settings">3.2.3.5. Default App Settings</h4> 814 815 816 <p>Android includes settings that provide users an easy way to select their 817 default applications, for example for Home screen or SMS. Where it makes sense, 818 device implementations MUST provide a similar settings menu and be compatible 819 with the intent filter pattern and API methods described in the SDK 820 documentation as below.</p> 821 822 <p>Device implementations:</p> 823 824 <ul> 825 <li>MUST honor the android.settings.HOME_SETTINGS intent to show a default app 826 settings menu for Home Screen, if the device implementation reports 827 android.software.home_screen [<a href="http://developer.android.com/reference/android/provider/Settings.html">Resources, 10]</a></li> 828 <li>MUST provide a settings menu that will call the 829 android.provider.Telephony.ACTION_CHANGE_DEFAULT intent to show a dialog to 830 change the default SMS application, if the device implementation reports 831 android.hardware.telephony [<a href="http://developer.android.com/reference/android/provider/Telephony.Sms.Intents.html">Resources, 9</a>]</li> 832 <li>MUST honor the android.settings.NFC_PAYMENT_SETTINGS intent to show a default 833 app settings menu for Tap and Pay, if the device implementation reports 834 android.hardware.nfc.hce [<a href="http://developer.android.com/reference/android/provider/Settings.html">Resources, 10]</a></li> 835 </ul> 836 837 <h2 id="3_3_native_api_compatibility">3.3. Native API Compatibility</h2> 838 839 840 <h3 id="3_3_1_application_binary_interfaces">3.3.1. Application Binary Interfaces</h3> 841 842 843 <p>Managed Dalvik bytecode can call into native code provided in the application 844 .apk file as an ELF .so file compiled for the appropriate device hardware 845 architecture. As native code is highly dependent on the underlying processor 846 technology, Android defines a number of Application Binary Interfaces (ABIs) in 847 the Android NDK. Device implementations MUST be compatible with one or more 848 defined ABIs, and MUST implement compatibility with the Android NDK, as below.</p> 849 850 <p>If a device implementation includes support for an Android ABI, it:</p> 851 852 <ul> 853 <li>MUST include support for code running in the managed environment to call into 854 native code, using the standard Java Native Interface (JNI) semantics</li> 855 <li>MUST be source-compatible (i.e. header compatible) and binary-compatible (for 856 the ABI) with each required library in the list below</li> 857 <li>MUST support the equivalent 32-bit ABI if any 64-bit ABI is supported</li> 858 <li>MUST accurately report the native Application Binary Interface (ABI) supported 859 by the device, via the android.os.Build.SUPPORTED_ABIS, 860 android.os.Build.SUPPORTED_32_BIT_ABIS, and 861 android.os.Build.SUPPORTED_64_BIT_ABIS parameters, each a comma separated list 862 of ABIs ordered from the most to the least preferred one</li> 863 <li>MUST report, via the above parameters, only those ABIs documented in the latest 864 version of the Android NDK, “NDK Programmer’s Guide | ABI Management” in docs/ 865 directory</li> 866 <li>SHOULD be built using the source code and header files available in the 867 upstream Android Open Source Project</li> 868 </ul> 869 870 <p>The following native code APIs MUST be available to apps that include native 871 code:</p> 872 873 <ul> 874 <li>libc (C library)</li> 875 <li>libm (math library)</li> 876 <li>Minimal support for C++</li> 877 <li>JNI interface</li> 878 <li>liblog (Android logging)</li> 879 <li>libz (Zlib compression)</li> 880 <li>libdl (dynamic linker)</li> 881 <li>libGLESv1_CM.so (OpenGL ES 1.x)</li> 882 <li>libGLESv2.so (OpenGL ES 2.0)</li> 883 <li>libGLESv3.so (OpenGL ES 3.x)</li> 884 <li>libEGL.so (native OpenGL surface management)</li> 885 <li>libjnigraphics.so</li> 886 <li>libOpenSLES.so (OpenSL ES 1.0.1 audio support)</li> 887 <li>libOpenMAXAL.so (OpenMAX AL 1.0.1 support)</li> 888 <li>libandroid.so (native Android activity support)</li> 889 <li>libmediandk.so (native media APIs support)</li> 890 <li>Support for OpenGL, as described below</li> 891 </ul> 892 893 <p>Note that future releases of the Android NDK may introduce support for 894 additional ABIs. If a device implementation is not compatible with an existing 895 predefined ABI, it MUST NOT report support for any ABIs at all.</p> 896 897 <p>Note that device implementations MUST include libGLESv3.so and it MUST symlink 898 (symbolic link) to libGLESv2.so. in turn, MUST export all the OpenGL ES 3.1 and 899 Android Extension Pack [<a href="http://developer.android.com/guide/topics/graphics/opengl.html#aep">Resources, 11</a>] function symbols as defined in the NDK release android-21. Although all the 900 symbols must be present, only the corresponding functions for OpenGL ES 901 versions and extensions actually supported by the device must be fully 902 implemented.</p> 903 904 <p>Native code compatibility is challenging. For this reason, device implementers 905 are <strong>very strongly encouraged</strong> to use the implementations of the libraries listed above from the upstream 906 Android Open Source Project. </p> 907 908 <h3 id="3_3_2_32-bit_arm_native_code_compatibility"> 909 3.3.2. 32-bit ARM Native Code Compatibility 910 </h3> 911 912 <p>The ARMv8 architecture deprecates several CPU operations, including some 913 operations used in existing native code. On 64-bit ARM devices, the following 914 deprecated operations MUST remain available to 32-bit native ARM code, either 915 through native CPU support or through software emulation:</p> 916 917 <ul> 918 <li>SWP and SWPB instructions</li> 919 <li>SETEND instruction</li> 920 <li>CP15ISB, CP15DSB, and CP15DMB barrier operations</li> 921 </ul> 922 923 <p>Legacy versions of the Android NDK used /proc/cpuinfo to discover CPU features 924 from 32-bit ARM native code. For compatibility with applications built using this 925 NDK, devices MUST include the following lines in /proc/cpuinfo when it is read 926 by 32-bit ARM applications:</p> 927 928 <ul> 929 <li>"Features: ", followed by a list of any optional ARMv7 CPU features 930 supported by the device</li> 931 <li>"CPU architecture: ", followed by an integer describing the device's 932 highest supported ARM architecture (e.g., "8" for ARMv8 devices)</li> 933 </ul> 934 935 <p>These requirements only apply when /proc/cpuinfo is read by 32-bit ARM 936 applications. Devices SHOULD not alter /proc/cpuinfo when read by 64-bit ARM or 937 non-ARM applications.</p> 938 939 <h2 id="3_4_web_compatibility">3.4. Web Compatibility</h2> 940 941 942 <h3 id="3_4_1_webview_compatibility">3.4.1. WebView Compatibility</h3> 943 944 <div class="note"> 945 <p>Android Watch devices MAY, but all other device implementations MUST provide 946 a complete implementation of the android.webkit.Webview API.</p> 947 </div> 948 949 950 <p>The platform feature android.software.webview MUST be reported on any device 951 that provides a complete implementation of the android.webkit.WebView API, and 952 MUST NOT be reported on devices without a complete implementation of the API. 953 The Android Open Source implementation uses code from the Chromium Project to 954 implement the android.webkit.WebView [<a href="http://developer.android.com/reference/android/webkit/WebView.html">Resources, 12</a>]. Because it is not feasible to develop a comprehensive test suite for a web 955 rendering system, device implementers MUST use the specific upstream build of 956 Chromium in the WebView implementation. Specifically:</p> 957 958 <ul> 959 <li>Device android.webkit.WebView implementations MUST be based on the Chromium 960 build from the upstream Android Open Source Project for Android 5.1. This build 961 includes a specific set of functionality and security fixes for the WebView [<a href="http://www.chromium.org/">Resources, 13</a>].</li> 962 <li>The user agent string reported by the WebView MUST be in this format: 963 <p>Mozilla/5.0 (Linux; Android $(VERSION); $(MODEL) Build/$(BUILD)$(WEBVIEW)) 964 AppleWebKit/537.36 (KHTML, like Gecko) Version/4.0 $(CHROMIUM_VER) Mobile 965 Safari/537.36</p> 966 <ul> 967 <li>The value of the $(VERSION) string MUST be the same as the value for 968 android.os.Build.VERSION.RELEASE.</li> 969 <li>The $(WEBVIEW) string MAY be omitted, but if included MUST be "; wv" to 970 note that this is a webview</li> 971 <li>The value of the $(MODEL) string MUST be the same as the value for 972 android.os.Build.MODEL.</li> 973 <li>The value of the $(BUILD) string MUST be the same as the value for 974 android.os.Build.ID.</li> 975 <li>The value of the $(CHROMIUM_VER) string MUST be the version of Chromium in the 976 upstream Android Open Source Project.</li> 977 <li>Device implementations MAY omit Mobile in the user agent string.</li> 978 </ul></li></ul> 979 980 <p>The WebView component SHOULD include support for as many HTML5 features as 981 possible and if it supports the feature SHOULD conform to the HTML5 982 specification [<a href="http://html.spec.whatwg.org/multipage/">Resources, 14</a>].</p> 983 984 <h3 id="3_4_2_browser_compatibility">3.4.2. Browser Compatibility</h3> 985 986 <div class="note"> 987 <p>Android Television, Watch, and Android Automotive implementations MAY omit a 988 browser application, but MUST support the public intent patterns as described in 989 <a href="#3_2_3_1_core_application_intents">section 3.2.3.1</a>. All other types 990 of device implementations MUST include a standalone Browser application for 991 general user web browsing.</p> 992 </div> 993 994 <p>The standalone Browser MAY be based on a browser technology other than WebKit. 995 However, even if an alternate Browser application is used, the 996 android.webkit.WebView component provided to third-party applications MUST be 997 based on WebKit, as described in <a href="#3_4_1_webview_compatibility">section 3.4.1</a>.</p> 998 999 <p>Implementations MAY ship a custom user agent string in the standalone Browser 1000 application.</p> 1001 1002 <p>The standalone Browser application (whether based on the upstream WebKit 1003 Browser application or a third-party replacement) SHOULD include support for as 1004 much of HTML5 [<a href="http://html.spec.whatwg.org/multipage/">Resources, 14</a>] as possible. Minimally, device implementations MUST support each of these 1005 APIs associated with HTML5:</p> 1006 1007 <ul> 1008 <li>application cache/offline operation [<a href="http://www.w3.org/html/wg/drafts/html/master/browsers.html#offline">Resources, 15</a>]</li> 1009 <li>the <video> tag [<a href="http://www.w3.org/html/wg/drafts/html/master/semantics.html#video">Resources, 16</a>]</li> 1010 <li>geolocation [<a href="http://www.w3.org/TR/geolocation-API/">Resources, 17</a>]</li> 1011 </ul> 1012 1013 <p>Additionally, device implementations MUST support the HTML5/W3C webstorage API 1014 [<a href="http://www.w3.org/TR/webstorage/">Resources, 18</a>], and SHOULD support the HTML5/W3C IndexedDB API [<a href="http://www.w3.org/TR/IndexedDB/">Resources, 19</a>]. Note that as the web development standards bodies are transitioning to favor 1015 IndexedDB over webstorage, IndexedDB is expected to become a required component 1016 in a future version of Android.</p> 1017 1018 <h2 id="3_5_api_behavioral_compatibility">3.5. API Behavioral Compatibility</h2> 1019 1020 1021 <p>The behaviors of each of the API types (managed, soft, native, and web) must be 1022 consistent with the preferred implementation of the upstream Android Open 1023 Source Project [<a href="http://source.android.com/">Resources, 2</a>]. Some specific areas of compatibility are:</p> 1024 1025 <ul> 1026 <li>Devices MUST NOT change the behavior or semantics of a standard intent.</li> 1027 <li>Devices MUST NOT alter the lifecycle or lifecycle semantics of a particular 1028 type of system component (such as Service, Activity, ContentProvider, etc.).</li> 1029 <li>Devices MUST NOT change the semantics of a standard permission.</li> 1030 </ul> 1031 1032 <p>The above list is not comprehensive. The Compatibility Test Suite (CTS) tests 1033 significant portions of the platform for behavioral compatibility, but not all. 1034 It is the responsibility of the implementer to ensure behavioral compatibility 1035 with the Android Open Source Project. For this reason, device implementers 1036 SHOULD use the source code available via the Android Open Source Project where 1037 possible, rather than re-implement significant parts of the system.</p> 1038 1039 <h2 id="3_6_api_namespaces">3.6. API Namespaces</h2> 1040 1041 1042 <p>Android follows the package and class namespace conventions defined by the Java 1043 programming language. To ensure compatibility with third-party applications, 1044 device implementers MUST NOT make any prohibited modifications (see below) to 1045 these package namespaces:</p> 1046 1047 <ul> 1048 <li>java.*</li> 1049 <li>javax.*</li> 1050 <li>sun.*</li> 1051 <li>android.*</li> 1052 <li>com.android.*</li> 1053 </ul> 1054 1055 <p><strong>Prohibited modifications include</strong>:</p> 1056 1057 <ul> 1058 <li>Device implementations MUST NOT modify the publicly exposed APIs on the Android 1059 platform by changing any method or class signatures, or by removing classes or 1060 class fields.</li> 1061 <li>Device implementers MAY modify the underlying implementation of the APIs, but 1062 such modifications MUST NOT impact the stated behavior and Java-language 1063 signature of any publicly exposed APIs.</li> 1064 <li>Device implementers MUST NOT add any publicly exposed elements (such as classes 1065 or interfaces, or fields or methods to existing classes or interfaces) to the 1066 APIs above.</li> 1067 </ul> 1068 1069 <p>A “publicly exposed element” is any construct which is not decorated with the“@hide” marker as used in the upstream Android source code. In other words, 1070 device implementers MUST NOT expose new APIs or alter existing APIs in the 1071 namespaces noted above. Device implementers MAY make internal-only 1072 modifications, but those modifications MUST NOT be advertised or otherwise 1073 exposed to developers.</p> 1074 1075 <p>Device implementers MAY add custom APIs, but any such APIs MUST NOT be in a 1076 namespace owned by or referring to another organization. For instance, device 1077 implementers MUST NOT add APIs to the com.google.* or similar namespace: only 1078 Google may do so. Similarly, Google MUST NOT add APIs to other companies' 1079 namespaces. Additionally, if a device implementation includes custom APIs 1080 outside the standard Android namespace, those APIs MUST be packaged in an 1081 Android shared library so that only apps that explicitly use them (via the 1082 <uses-library> mechanism) are affected by the increased memory usage of such 1083 APIs.</p> 1084 1085 <p>If a device implementer proposes to improve one of the package namespaces above 1086 (such as by adding useful new functionality to an existing API, or adding a new 1087 API), the implementer SHOULD visit <a href="http://source.android.com/">source.android.com</a> and begin the process for contributing changes and code, according to the 1088 information on that site.</p> 1089 1090 <p>Note that the restrictions above correspond to standard conventions for naming 1091 APIs in the Java programming language; this section simply aims to reinforce 1092 those conventions and make them binding through inclusion in this Compatibility 1093 Definition.</p> 1094 1095 <h2 id="3_7_runtime_compatibility">3.7. Runtime Compatibility</h2> 1096 1097 1098 <p>Device implementations MUST support the full Dalvik Executable (DEX) format and 1099 Dalvik bytecode specification and semantics [<a href="https://android.googlesource.com/platform/dalvik/+/lollipop-release/docs/">Resources, 20</a>]. Device implementers SHOULD use ART, the reference upstream implementation of 1100 the Dalvik Executable Format, and the reference implementation’s package 1101 management system.</p> 1102 1103 <p>Device implementations MUST configure Dalvik runtimes to allocate memory in 1104 accordance with the upstream Android platform, and as specified by the 1105 following table. (See <a href="#7_1_1_screen_configuration">section 7.1.1</a> for screen size and screen density definitions.)</p> 1106 1107 <p>Note that memory values specified below are considered minimum values and 1108 device implementations MAY allocate more memory per application.</p> 1109 1110 <table> 1111 <tr> 1112 <th>Screen Layout</th> 1113 <th>Screen Density</th> 1114 <th>Minimum Application Memory</th> 1115 </tr> 1116 <tr> 1117 <td rowspan="10">small/normal</td> 1118 <td>120 dpi (ldpi)</td> 1119 <td rowspan="2">32MB</td> 1120 </tr> 1121 <tr> 1122 <td>160 dpi (mdpi)</td> 1123 </tr> 1124 <tr> 1125 <td>213 dpi (tvdpi)</td> 1126 <td rowspan="3">48MB</td> 1127 </tr> 1128 <tr> 1129 <td>240 dpi (hdpi)</td> 1130 </tr> 1131 <tr> 1132 <td>280 dpi (280dpi)</td> 1133 </tr> 1134 <tr> 1135 <td>320 dpi (xhdpi)</td> 1136 <td>80MB</td> 1137 </tr> 1138 <tr> 1139 <td>400 dpi (400dpi)</td> 1140 <td>96MB</td> 1141 </tr> 1142 <tr> 1143 <td>480 dpi (xxhdpi)</td> 1144 <td>128MB</td> 1145 </tr> 1146 <tr> 1147 <td>560 dpi (560dpi)</td> 1148 <td>192MB</td> 1149 </tr> 1150 <tr> 1151 <td>640 dpi (xxxhdpi)</td> 1152 <td>256MB</td> 1153 </tr> 1154 <tr> 1155 <td rowspan="10">large</td> 1156 <td>120 dpi (ldpi)</td> 1157 <td>32MB</td> 1158 </tr> 1159 <tr> 1160 <td>160 dpi (mdpi)</td> 1161 <td>48MB</td> 1162 </tr> 1163 <tr> 1164 <td>213 dpi (tvdpi)</td> 1165 <td rowspan="2">80MB</td> 1166 </tr> 1167 <tr> 1168 <td>240 dpi (hdpi)</td> 1169 </tr> 1170 <tr> 1171 <td>280 dpi (280dpi)</td> 1172 <td>96MB</td> 1173 </tr> 1174 <tr> 1175 <td>320 dpi (xhdpi)</td> 1176 <td>128MB</td> 1177 </tr> 1178 <tr> 1179 <td>400 dpi (400dpi)</td> 1180 <td>192MB</td> 1181 </tr> 1182 <tr> 1183 <td>480 dpi (xxhdpi)</td> 1184 <td>256MB</td> 1185 </tr> 1186 <tr> 1187 <td>560 dpi (560dpi)</td> 1188 <td>384MB</td> 1189 </tr> 1190 <tr> 1191 <td>640 dpi (xxxhdpi)</td> 1192 <td>512MB</td> 1193 </tr> 1194 <tr> 1195 <td rowspan="10">xlarge</td> 1196 <td>120 dpi (ldpi)</td> 1197 <td>48MB</td> 1198 </tr> 1199 <tr> 1200 <td>160 dpi (mdpi)</td> 1201 <td>80MB</td> 1202 </tr> 1203 <tr> 1204 <td>213 dpi (tvdpi)</td> 1205 <td rowspan="2">96MB</td> 1206 </tr> 1207 <tr> 1208 <td>240 dpi (hdpi)</td> 1209 </tr> 1210 <tr> 1211 <td>280 dpi (280dpi)</td> 1212 <td>144MB</td> 1213 </tr> 1214 <tr> 1215 <td>320 dpi (xhdpi)</td> 1216 <td>192MB</td> 1217 </tr> 1218 <tr> 1219 <td>400 dpi (400dpi)</td> 1220 <td>288MB</td> 1221 </tr> 1222 <tr> 1223 <td>480 dpi (xxhdpi)</td> 1224 <td>384MB</td> 1225 </tr> 1226 <tr> 1227 <td>560 dpi (560dpi)</td> 1228 <td>576MB</td> 1229 </tr> 1230 <tr> 1231 <td>640 dpi (xxxhdpi)</td> 1232 <td>768MB</td> 1233 </tr> 1234 </table> 1235 1236 1237 <h2 id="3_8_user_interface_compatibility">3.8. User Interface Compatibility</h2> 1238 1239 1240 <h3 id="3_8_1_launcher_home_screen">3.8.1. Launcher (Home Screen)</h3> 1241 1242 1243 <p>Android includes a launcher application (home screen) and support for 1244 third-party applications to replace the device launcher (home screen). Device 1245 implementations that allow third-party applications to replace the device home 1246 screen MUST declare the platform feature android.software.home_screen.</p> 1247 1248 <h3 id="3_8_2_widgets">3.8.2. Widgets</h3> 1249 1250 <div class="note"> 1251 <p>Widgets are optional for all Android device implementations, but SHOULD be 1252 supported on Android Handheld devices.</p> 1253 </div> 1254 1255 1256 <p>Android defines a component type and corresponding API and lifecycle that 1257 allows applications to expose an “AppWidget” to the end user [<a href="http://developer.android.com/guide/practices/ui_guidelines/widget_design.html">Resources, 21</a>] a feature that is strongly RECOMMENDED to be supported on Handheld Device 1258 implementations. Device implementations that support embedding widgets on the 1259 home screen MUST meet the following requirements and declare support for 1260 platform feature android.software.app_widgets.</p> 1261 1262 <ul> 1263 <li>Device launchers MUST include built-in support for AppWidgets, and expose user 1264 interface affordances to add, configure, view, and remove AppWidgets directly 1265 within the Launcher.</li> 1266 <li>Device implementations MUST be capable of rendering widgets that are 4 x 4 in 1267 the standard grid size. See the App Widget Design Guidelines in the Android SDK 1268 documentation [<a href="http://developer.android.com/guide/practices/ui_guidelines/widget_design.html">Resources, 21</a>] for details.</li> 1269 <li>Device implementations that include support for lock screen MAY support 1270 application widgets on the lock screen.</li> 1271 </ul> 1272 1273 <h3 id="3_8_3_notifications">3.8.3. Notifications</h3> 1274 1275 1276 <p>Android includes APIs that allow developers to notify users of notable events [<a href="http://developer.android.com/guide/topics/ui/notifiers/notifications.html">Resources, 22</a>], using hardware and software features of the device.</p> 1277 1278 <p>Some APIs allow applications to perform notifications or attract attention 1279 using hardware—specifically sound, vibration, and light. Device implementations 1280 MUST support notifications that use hardware features, as described in the SDK 1281 documentation, and to the extent possible with the device implementation 1282 hardware. For instance, if a device implementation includes a vibrator, it MUST 1283 correctly implement the vibration APIs. If a device implementation lacks 1284 hardware, the corresponding APIs MUST be implemented as no-ops. This behavior 1285 is further detailed in <a href="#7_hardware_compatibility">section 7</a>.</p> 1286 1287 <p>Additionally, the implementation MUST correctly render all resources (icons, animation files 1288 etc.) provided for in the APIs 1289 [<a href="https://developer.android.com/guide/topics/resources/available-resources.html">Resources, 23</a>], 1290 or in the Status/System Bar icon style guide 1291 [<a href="http://developer.android.com/design/style/iconography.html">Resources, 24</a>], 1292 which in the case of an Android Television device includes the possibility to not display the 1293 notifications. Device implementers MAY provide an alternative user experience for 1294 notifications than that provided by the reference Android Open Source 1295 implementation; however, such alternative notification systems MUST support 1296 existing notification resources, as above. </p> 1297 1298 <p>Android includes support for various notifications, such as:</p> 1299 1300 <ul> 1301 <li><strong>Rich notifications</strong>. Interactive Views for ongoing notifications.</li> 1302 <li><strong>Heads-up notifications</strong>. Interactive Views users can act on or dismiss without leaving the current app.</li> 1303 <li><strong>Lockscreen notifications</strong>. Notifications shown over a lock screen with granular control on visibility.</li> 1304 </ul> 1305 1306 <p>Android device implementations, when such notifications are made visible, MUST properly execute 1307 Rich and Heads-up notifications and include the title/name, icon, text as documented in the Android 1308 APIs <a href="https://developer.android.com/design/patterns/notifications.html">[Resources, 25]</a>. 1309 </p> 1310 1311 <p>Android includes Notification Listener Service APIs that allow apps (once 1312 explicitly enabled by the user) to receive a copy of all notifications as they 1313 are posted or updated. Device implementations MUST correctly and promptly send 1314 notifications in their entirety to all such installed and user-enabled listener 1315 services, including any and all metadata attached to the Notification object.</p> 1316 1317 <h3 id="3_8_4_search">3.8.4. Search</h3> 1318 1319 1320 <p>Android includes APIs [<a href="http://developer.android.com/reference/android/app/SearchManager.html">Resources, 26</a>] that allow developers to incorporate search into their applications, and 1321 expose their application’s data into the global system search. Generally 1322 speaking, this functionality consists of a single, system-wide user interface 1323 that allows users to enter queries, displays suggestions as users type, and 1324 displays results. The Android APIs allow developers to reuse this interface to 1325 provide search within their own apps, and allow developers to supply results to 1326 the common global search user interface.</p> 1327 1328 <p>Android device implementations SHOULD include global search, a single, shared, 1329 system-wide search user interface capable of real-time suggestions in response 1330 to user input. Device implementations SHOULD implement the APIs that allow 1331 developers to reuse this user interface to provide search within their own 1332 applications. Device implementations that implement the global search interface 1333 MUST implement the APIs that allow third-party applications to add suggestions 1334 to the search box when it is run in global search mode. If no third-party 1335 applications are installed that make use of this functionality, the default 1336 behavior SHOULD be to display web search engine results and suggestions.</p> 1337 1338 <h3 id="3_8_5_toasts">3.8.5. Toasts</h3> 1339 1340 1341 <p>Applications can use the “Toast” API to display short non-modal strings to the 1342 end user, that disappear after a brief period of time [<a href="http://developer.android.com/reference/android/widget/Toast.html">Resources, 27</a>]. Device implementations MUST display Toasts from applications to end users in 1343 some high-visibility manner.</p> 1344 1345 <h3 id="3_8_6_themes">3.8.6. Themes</h3> 1346 1347 1348 <p>Android provides “themes” as a mechanism for applications to apply styles 1349 across an entire Activity or application.</p> 1350 1351 <p>Android includes a “Holo” theme family as a set of defined styles for 1352 application developers to use if they want to match the Holo theme look and 1353 feel as defined by the Android SDK [<a href="http://developer.android.com/guide/topics/ui/themes.html">Resources, 28</a>]. Device implementations MUST NOT alter any of the Holo theme attributes 1354 exposed to applications [<a href="http://developer.android.com/reference/android/R.style.html">Resources, 29</a>].</p> 1355 1356 <p>Android includes a “Material” theme family as a set of defined styles for 1357 application developers to use if they want to match the design theme’s look and 1358 feel across the wide variety of different Android device types. Device 1359 implementations MUST support the “Material” theme family and MUST NOT alter any 1360 of the Material theme attributes or their assets exposed to applications [<a href="http://developer.android.com/reference/android/R.style.html#Theme_Material">Resources, 30</a>].</p> 1361 1362 <p>Android also includes a “Device Default” theme family as a set of defined 1363 styles for application developers to use if they want to match the look and 1364 feel of the device theme as defined by the device implementer. Device 1365 implementations MAY modify the Device Default theme attributes exposed to 1366 applications [<a href="http://developer.android.com/reference/android/R.style.html">Resources, 29</a>].</p> 1367 1368 <p>Android supports a new variant theme with translucent system bars, which allows 1369 application developers to fill the area behind the status and navigation bar 1370 with their app content. To enable a consistent developer experience in this 1371 configuration, it is important the status bar icon style is maintained across 1372 different device implementations. Therefore, Android device implementations 1373 MUST use white for system status icons (such as signal strength and battery 1374 level) and notifications issued by the system, unless the icon is indicating a 1375 problematic status [<a href="http://developer.android.com/reference/android/R.style.html">Resources, 29</a>].</p> 1376 1377 <h3 id="3_8_7_live_wallpapers">3.8.7. Live Wallpapers</h3> 1378 1379 1380 <p>Android defines a component type and corresponding API and lifecycle that 1381 allows applications to expose one or more “Live Wallpapers” to the end user [<a href="http://developer.android.com/reference/android/service/wallpaper/WallpaperService.html">Resources, 31</a>]. Live wallpapers are animations, patterns, or similar images with limited 1382 input capabilities that display as a wallpaper, behind other applications.</p> 1383 1384 <p>Hardware is considered capable of reliably running live wallpapers if it can 1385 run all live wallpapers, with no limitations on functionality, at a reasonable 1386 frame rate with no adverse effects on other applications. If limitations in the 1387 hardware cause wallpapers and/or applications to crash, malfunction, consume 1388 excessive CPU or battery power, or run at unacceptably low frame rates, the 1389 hardware is considered incapable of running live wallpaper. As an example, some 1390 live wallpapers may use an OpenGL 2.0 or 3.x context to render their content. 1391 Live wallpaper will not run reliably on hardware that does not support multiple 1392 OpenGL contexts because the live wallpaper use of an OpenGL context may 1393 conflict with other applications that also use an OpenGL context.</p> 1394 1395 <p>Device implementations capable of running live wallpapers reliably as described 1396 above SHOULD implement live wallpapers, and when implemented MUST report the 1397 platform feature flag android.software.live_wallpaper.</p> 1398 1399 <h3 id="3_8_8_activity_switching">3.8.8. Activity Switching</h3> 1400 1401 <div class="note"> 1402 <p>As the Recent function navigation key is OPTIONAL, the requirements to 1403 implement the overview screen is OPTIONAL for Android Television devices and 1404 Android Watch devices.</p> 1405 </div> 1406 1407 1408 <p>The upstream Android source code includes the overview screen [<a href="http://developer.android.com/guide/components/recents.html">Resources, 32</a>], a system-level user interface for task switching and displaying recently 1409 accessed activities and tasks using a thumbnail image of the application’s 1410 graphical state at the moment the user last left the application. Device 1411 implementations including the recents function navigation key as detailed in <a href="#7_2_3_navigation_keys">section 7.2.3</a>, MAY alter the interface but MUST meet the following requirements:</p> 1412 1413 <ul> 1414 <li>MUST display affiliated recents as a group that moves together.</li> 1415 <li>MUST support at least up to 20 displayed activities.</li> 1416 <li>MUST at least display the title of 4 activities at a time.</li> 1417 <li>SHOULD display highlight color, icon, screen title in recents.</li> 1418 <li>MUST implement the screen pinning behavior [<a href="http://developer.android.com/about/versions/android-5.0.html#ScreenPinning">Resources, 33</a>] and provide the user with a settings menu to toggle the feature.</li> 1419 <li>SHOULD display a closing affordance ("x") but MAY delay this until user 1420 interacts with screens.</li> 1421 </ul> 1422 1423 <p>Device implementations are STRONGLY ENCOURAGED to use the upstream Android user 1424 interface (or a similar thumbnail-based interface) for the overview screen.</p> 1425 1426 <h3 id="3_8_9_input_management">3.8.9. Input Management</h3> 1427 1428 1429 <p>Android includes support for Input Management and support for third-party input 1430 method editors [<a href="http://developer.android.com/guide/topics/text/creating-input-method.html">Resources, 34</a>]. Device implementations that allow users to use third-party input methods on 1431 the device MUST declare the platform feature android.software.input_methods and 1432 support IME APIs as defined in the Android SDK documentation.</p> 1433 1434 <p>Device implementations that declare the android.software.input_methods feature 1435 MUST provide a user-accessible mechanism to add and configure third-party input 1436 methods. Device implementations MUST display the settings interface in response 1437 to the android.settings.INPUT_METHOD_SETTINGS intent.</p> 1438 1439 <h3 id="3_8_10_lock_screen_media_control">3.8.10. Lock Screen Media Control</h3> 1440 1441 1442 <p>The Remote Control Client API is deprecated from Android 5.0 in favor of the 1443 Media Notification Template that allows media applications to integrate with 1444 playback controls that are displayed on the lock screen [<a href="http://developer.android.com/reference/android/app/Notification.MediaStyle.html">Resources, 35</a>]. 1445 Device implementations that support a lock screen, unless an Android Automotive or Watch 1446 implementation, MUST display the Lockscreen Notifications including the Media Notification 1447 Template.</p> 1448 1449 <h3 id="3_8_11_dreams">3.8.11. Dreams</h3> 1450 1451 1452 <p>Android includes support for interactive screensavers called Dreams [<a href="http://developer.android.com/reference/android/service/dreams/DreamService.html">Resources, 36</a>]. Dreams allows users to interact with applications when a device connected to 1453 a power source is idle or docked in a desk dock. Android Watch devices MAY 1454 implement Dreams, but other types of device implementations SHOULD include 1455 support for Dreams and provide a settings option for users to configure Dreams 1456 in response to the android.settings.DREAM_SETTINGS intent.</p> 1457 1458 <h3 id="3_8_12_location">3.8.12. Location</h3> 1459 1460 1461 <p>When a device has a hardware sensor (e.g. GPS) that is capable of providing the 1462 location coordinates, location modes MUST be displayed in the Location menu 1463 within Settings [<a href="http://developer.android.com/reference/android/provider/Settings.Secure.html#LOCATION_MODE">Resources, 37</a>].</p> 1464 1465 <h3 id="3_8_13_unicode_and_font">3.8.13. Unicode and Font</h3> 1466 1467 1468 <p>Android includes support for color emoji characters. When Android device 1469 implementations include an IME, devices SHOULD provide an input method to the 1470 user for the Emoji characters defined in Unicode 6.1 [<a href="http://www.unicode.org/versions/Unicode6.1.0/">Resources, 38</a>]. All devices MUST be capable of rendering these emoji characters in color glyph.</p> 1471 1472 <p>Android includes support for Roboto 2 font with different 1473 weights—sans-serif-thin, sans-serif-light, sans-serif-medium, sans-serif-black, 1474 sans-serif-condensed, sans-serif-condensed-light—which MUST all be included for 1475 the languages available on the device and full Unicode 7.0 coverage of Latin, 1476 Greek, and Cyrillic, including the Latin Extended A, B, C, and D ranges, and 1477 all glyphs in the currency symbols block of Unicode 7.0.</p> 1478 1479 <h2 id="3_9_device_administration">3.9. Device Administration</h2> 1480 1481 1482 <p>Android includes features that allow security-aware applications to perform 1483 device administration functions at the system level, such as enforcing password 1484 policies or performing remote wipe, through the Android Device Administration 1485 API [<a href="http://developer.android.com/guide/topics/admin/device-admin.html">Resources, 39</a>]. 1486 Device implementations MUST provide an implementation of the DevicePolicyManager class 1487 [<a href="http://developer.android.com/reference/android/app/admin/DevicePolicyManager.html">Resources, 40</a>]. 1488 Device implementations that include support for PIN (numeric) or PASSWORD 1489 (alphanumeric) based lock screens MUST support the full range of device 1490 administration policies defined in the Android SDK documentation 1491 [<a href="http://developer.android.com/guide/topics/admin/device-admin.html">Resources, 39</a>] 1492 and report the platform feature android.software.device_admin.</p> 1493 1494 <p>Device implementations MAY have a preinstalled application performing device 1495 administration functions but this application MUST NOT be set out-of-the box as 1496 the default Device Owner app [<a href="http://developer.android.com/reference/android/app/admin/DevicePolicyManager.html#isDeviceOwnerApp(java.lang.String)">Resources, 41</a>].</p> 1497 1498 <h2 id="3_10_accessibility">3.10. Accessibility</h2> 1499 1500 1501 <p>Android provides an accessibility layer that helps users with disabilities to 1502 navigate their devices more easily. In addition, Android provides platform APIs 1503 that enable accessibility service implementations to receive callbacks for user 1504 and system events and generate alternate feedback mechanisms, such as 1505 text-to-speech, haptic feedback, and trackball/d-pad navigation [<a href="http://developer.android.com/reference/android/accessibilityservice/AccessibilityService.html">Resources, 42</a>].</p> 1506 1507 <p>Device implementations include the following requirements:</p> 1508 1509 <ul> 1510 <li>Android Automotive implementations SHOULD provide an implementation of the 1511 Android accessibility framework consistent with the default Android 1512 implementation.</li> 1513 <li>Device implementations (Android Automotive excluded) MUST provide an 1514 implementation of the Android accessibility framework consistent with the 1515 default Android implementation.</li> 1516 <li>Device implementations (Android Automotive excluded) MUST support 1517 third-party accessibility service implementations through the 1518 android.accessibilityservice APIs 1519 [<a href="http://developer.android.com/reference/android/view/accessibility/package-summary.html">Resources, 43</a>]</li> 1520 <li>Device implementations (Android Automotive excluded) MUST generate 1521 AccessibilityEvents and deliver these events to all registered 1522 AccessibilityService implementations in a manner consistent with the default 1523 Android implementation</li> 1524 <li> Device implementations (Android Automotive and Android Watch devices with 1525 no audio output excluded), MUST provide a user-accessible mechanism to enable 1526 and disable accessibility services, and MUST display this interface in response 1527 to the android.provider.Settings.ACTION_ACCESSIBILITY_SETTINGS intent.</li> 1528 </ul> 1529 1530 <p>Additionally, device implementations SHOULD provide an implementation of an 1531 accessibility service on the device, and SHOULD provide a mechanism for users 1532 to enable the accessibility service during device setup. An open source 1533 implementation of an accessibility service is available from the Eyes Free 1534 project [<a href="http://code.google.com/p/eyes-free/">Resources, 44</a>].</p> 1535 1536 <h2 id="3_11_text-to-speech">3.11. Text-to-Speech</h2> 1537 1538 1539 <p>Android includes APIs that allow applications to make use of text-to-speech 1540 (TTS) services and allows service providers to provide implementations of TTS 1541 services [<a href="http://developer.android.com/reference/android/speech/tts/package-summary.html">Resources, 45</a>]. Device implementations reporting the feature android.hardware.audio.output 1542 MUST meet these requirements related to the Android TTS framework. </p> 1543 1544 <p>Android Automotive implementations:</p> 1545 <ul> 1546 <li>MUST support the Android TTS framework APIs.</li> 1547 <li>MAY support installation of third-party TTS engines. If supported, partners 1548 MUST provide a user-accessible interface that allows the user to select a TTS 1549 engine for use at system level.</li> 1550 </ul> 1551 1552 <p>All other device implementations:</p> 1553 1554 <ul> 1555 <li> MUST support the Android TTS framework APIs and SHOULD include a TTS engine 1556 supporting the languages available on the device. Note that the upstream 1557 Android open source software includes a full-featured TTS engine 1558 implementation. 1559 <li> MUST support installation of third-party TTS engines 1560 <li> MUST provide a user-accessible interface that allows users to select a TTS 1561 engine for use at the system level 1562 </ul> 1563 1564 <h2 id="3_12_tv_input_framework">3.12. TV Input Framework</h2> 1565 1566 1567 <p>The Android Television Input Framework (TIF) simplifies the delivery of live 1568 content to Android Television devices. TIF provides a standard API to create 1569 input modules that control Android Television devices. Android Television 1570 device implementations MUST support Television Input Framework [<a href="http://source.android.com/devices/tv/index.html">Resources, 46</a>].</p> 1571 1572 <p>Device implementations that support TIF MUST declare the platform feature 1573 android.software.live_tv.</p> 1574 1575 <h1 id="4_application_packaging_compatibility">4. Application Packaging Compatibility</h1> 1576 1577 1578 <p>Device implementations MUST install and run Android “.apk” files as generated 1579 by the “aapt” tool included in the official Android SDK [<a href="http://developer.android.com/tools/help/index.html">Resources, 47</a>].</p> 1580 1581 <p>Devices implementations MUST NOT extend either the .apk [<a href="http://developer.android.com/guide/components/fundamentals.html">Resources, 48</a>], Android Manifest [<a href="http://developer.android.com/guide/topics/manifest/manifest-intro.html">Resources, 49</a>], Dalvik bytecode [<a href="https://android.googlesource.com/platform/dalvik/+/lollipop-release/docs/">Resources, 20</a>], or RenderScript bytecode formats in such a way that would prevent those 1582 files from installing and running correctly on other compatible devices.</p> 1583 1584 <h1 id="5_multimedia_compatibility">5. Multimedia Compatibility</h1> 1585 1586 1587 <h2 id="5_1_media_codecs">5.1. Media Codecs</h2> 1588 1589 1590 <p>Device implementations MUST support the core media formats specified in the 1591 Android SDK documentation [<a href="http://developer.android.com/guide/appendix/media-formats.html">Resources, 50</a>] except where explicitly permitted in this document. Specifically, device 1592 implementations MUST support the media formats, encoders, decoders, file types, 1593 and container formats defined in the tables below and reported via MediaCodecList 1594 [<a href="http://developer.android.com/reference/android/media/MediaCodecList.html">Resources,112</a>]. 1595 Device implementations MUST also be able to decode all profiles reported in its CamcorderProfile 1596 [<a href="http://developer.android.com/reference/android/media/CamcorderProfile.html">Resources, 1597 113</a>]. 1598 1599 All of these codecs are 1600 provided as software implementations in the preferred Android implementation 1601 from the Android Open Source Project.</p> 1602 1603 <p>Please note that neither Google nor the Open Handset Alliance make any 1604 representation that these codecs are free from third-party patents. Those 1605 intending to use this source code in hardware or software products are advised 1606 that implementations of this code, including in open source software or 1607 shareware, may require patent licenses from the relevant patent holders.</p> 1608 1609 <h3 id="5_1_1_audio_codecs">5.1.1. Audio Codecs</h3> 1610 1611 <table> 1612 <tr> 1613 <th>Format/Codec</th> 1614 <th>Encoder</th> 1615 <th>Decoder</th> 1616 <th>Details</th> 1617 <th>Supported File Types/Container Formats</th> 1618 </tr> 1619 <tr> 1620 <td>MPEG-4 AAC Profile</p> 1621 1622 <p>(AAC LC)</td> 1623 <td>REQUIRED<sup>1</sup></td> 1624 <td>REQUIRED</td> 1625 <td>Support for mono/stereo/5.0/5.1<sup>2</sup> content with standard sampling rates from 8 to 1626 48 kHz.</td> 1627 <td> 1628 <ul> 1629 <li class="table_list">3GPP (.3gp)</li> 1630 <li class="table_list">MPEG-4 (.mp4, .m4a)</li> 1631 <li class="table_list">ADTS raw AAC (.aac, decode in Android 3.1+, encode in Android 4.0+, ADIF not 1632 supported)</li> 1633 <li class="table_list">MPEG-TS (.ts, not seekable, Android 3.0+)</li></ul></td> 1634 </tr> 1635 <tr> 1636 <td>MPEG-4 HE AAC Profile (AAC+)</td> 1637 <td>REQUIRED<sup>1</sup><br>(Android 4.1+)</td> 1638 <td>REQUIRED</td> 1639 <td>Support for mono/stereo/5.0/5.1<sup>2</sup> content with standard sampling rates from 16 1640 to 48 kHz.</td> 1641 <td></td> 1642 </tr> 1643 <tr> 1644 <td>MPEG-4 HE AACv2</p> 1645 1646 <p>Profile (enhanced AAC+)</td> 1647 <td> </td> 1648 <td>REQUIRED</td> 1649 <td>Support for mono/stereo/5.0/5.1<sup>2</sup> content with standard sampling rates from 16 1650 to 48 kHz.</td> 1651 <td></td> 1652 </tr> 1653 <tr> 1654 <td>AAC ELD (enhanced low delay AAC)</td> 1655 <td>REQUIRED<sup>1</sup> </p> 1656 1657 <p>(Android 4.1+)</td> 1658 <td>REQUIRED</p> 1659 1660 <p>(Android 4.1+)</td> 1661 <td>Support for mono/stereo content with standard sampling rates from 16 to 48 kHz.</td> 1662 <td></td> 1663 </tr> 1664 <tr> 1665 <td>AMR-NB</td> 1666 <td>REQUIRED<sup>3</sup></td> 1667 <td>REQUIRED<sup>3</sup></td> 1668 <td>4.75 to 12.2 kbps sampled @ 8kHz</td> 1669 <td>3GPP (.3gp)</td> 1670 </tr> 1671 <tr> 1672 <td>AMR-WB</td> 1673 <td>REQUIRED<sup>3</sup></td> 1674 <td>REQUIRED<sup>3</sup></td> 1675 <td>9 rates from 6.60 kbit/s to 23.85 kbit/s sampled @ 16kHz</td> 1676 <td></td> 1677 </tr> 1678 <tr> 1679 <td>FLAC</td> 1680 <td></td> 1681 <td>REQUIRED <br>(Android 3.1+)</td> 1682 <td>Mono/Stereo (no multichannel). Sample rates up to 48 kHz (but up to 44.1 kHz is 1683 recommended on devices with 44.1 kHz output, as the 48 to 44.1 kHz downsampler 1684 does not include a low-pass filter). 16-bit recommended; no dither applied for 1685 24-bit.</td> 1686 <td>FLAC (.flac) only</td> 1687 </tr> 1688 <tr> 1689 <td>MP3</td> 1690 <td></td> 1691 <td>REQUIRED</td> 1692 <td>Mono/Stereo 8-320Kbps constant (CBR) or variable bitrate (VBR)</td> 1693 <td>MP3 (.mp3)</td> 1694 </tr> 1695 <tr> 1696 <td>MIDI</td> 1697 <td></td> 1698 <td>REQUIRED</td> 1699 <td>MIDI Type 0 and 1. DLS Version 1 and 2. XMF and Mobile XMF. Support for 1700 ringtone formats RTTTL/RTX, OTA, and iMelody</td> 1701 <td><ul> 1702 <li class="table_list">Type 0 and 1 (.mid, .xmf, .mxmf)</li> 1703 <li class="table_list">RTTTL/RTX (.rtttl, .rtx)</li> 1704 <li class="table_list">OTA (.ota)</li> 1705 <li class="table_list">iMelody (.imy)</li></ul></td> 1706 </tr> 1707 <tr> 1708 <td>Vorbis</td> 1709 <td></td> 1710 <td>REQUIRED</td> 1711 <td></td> 1712 <td><ul> 1713 <li class="table_list">Ogg (.ogg)</li> 1714 <li class="table_list">Matroska (.mkv, Android 4.0+)</li></ul></td> 1715 </tr> 1716 <tr> 1717 <td>PCM/WAVE</td> 1718 <td>REQUIRED<sup>4</sup><br> (Android 4.1+)</td> 1719 <td>REQUIRED</td> 1720 <td>16-bit linear PCM (rates up to limit of hardware). Devices MUST support 1721 sampling rates for raw PCM recording at 8000, 11025, 16000, and 44100 Hz 1722 frequencies.</td> 1723 <td>WAVE (.wav)</td> 1724 </tr> 1725 <tr> 1726 <td>Opus</td> 1727 <td></td> 1728 <td>REQUIRED<br> (Android 5.0+)</td> 1729 <td></td> 1730 <td>Matroska (.mkv)</td> 1731 </tr> 1732 </table> 1733 1734 1735 <p class="table_footnote"> 1 Required for device implementations that define android.hardware.microphone 1736 but optional for Android Watch device implementations.</p> 1737 1738 <p class="table_footnote">2 Only downmix of 5.0/5.1 content is required; recording or rendering more than 1739 2 channels is optional.</p> 1740 1741 <p class="table_footnote">3 Required for Android Handheld device implementations. </p> 1742 1743 <p class="table_footnote">4 Required for device implementations that define android.hardware.microphone, 1744 including Android Watch device implementations.</p> 1745 1746 <h3 id="5_1_2_image_codecs">5.1.2. Image Codecs</h3> 1747 1748 <table> 1749 <tr> 1750 <th>Format/Codec</th> 1751 <th>Encoder</th> 1752 <th>Decoder</th> 1753 <th>Details</th> 1754 <th>Supported File Types/Container Formats</th> 1755 </tr> 1756 <tr> 1757 <td>JPEG</td> 1758 <td>REQUIRED</td> 1759 <td>REQUIRED</td> 1760 <td>Base+progressive</td> 1761 <td>JPEG (.jpg)</td> 1762 </tr> 1763 <tr> 1764 <td>GIF</td> 1765 <td></td> 1766 <td>REQUIRED</td> 1767 <td></td> 1768 <td>GIF (.gif)</td> 1769 </tr> 1770 <tr> 1771 <td>PNG</td> 1772 <td>REQUIRED</td> 1773 <td>REQUIRED</td> 1774 <td></td> 1775 <td>PNG (.png)</td> 1776 </tr> 1777 <tr> 1778 <td>BMP</td> 1779 <td></td> 1780 <td>REQUIRED</td> 1781 <td></td> 1782 <td>BMP (.bmp)</td> 1783 </tr> 1784 <tr> 1785 <td>WebP</td> 1786 <td>REQUIRED</td> 1787 <td>REQUIRED</td> 1788 <td></td> 1789 <td>WebP (.webp)</td> 1790 </tr> 1791 </table> 1792 1793 1794 <h3 id="5_1_3_video_codecs">5.1.3. Video Codecs</h3> 1795 1796 <p>Video codecs are optional for Android Watch device implementations.</p> 1797 1798 <table> 1799 <tr> 1800 <th>Format/Codec</th> 1801 <th>Encoder</th> 1802 <th>Decoder</th> 1803 <th>Details</th> 1804 <th>Supported File Types/<br>Container Formats</th> 1805 </tr> 1806 <tr> 1807 <td>H.263</td> 1808 <td>REQUIRED<sup>1</sup></td> 1809 <td>REQUIRED<sup>2</sup></td> 1810 <td></td> 1811 <td><ul> 1812 <li class="table_list">3GPP (.3gp)</li> 1813 <li class="table_list">MPEG-4 (.mp4)</li></ul></td> 1814 </tr> 1815 <tr> 1816 <td>H.264 AVC</td> 1817 <td>REQUIRED<sup>2</sup></td> 1818 <td>REQUIRED<sup>2</sup></td> 1819 <td>See <a href="#5_2_video_encoding">section 5.2 </a>and <a href="#5_3_video_decoding">5.3</a> for details</td> 1820 <td><ul> 1821 <li class="table_list">3GPP (.3gp)</li> 1822 <li class="table_list">MPEG-4 (.mp4)</li> 1823 <li class="table_list">MPEG-TS (.ts, AAC audio only, not seekable, Android 3.0+)</li></ul></td> 1824 </tr> 1825 <tr> 1826 <td>H.265 HEVC</td> 1827 <td></td> 1828 <td>REQUIRED<sup>5</sup></td> 1829 <td>See <a href="#5_3_video_decoding">section 5.3</a> for details</td> 1830 <td>MPEG-4 (.mp4)</td> 1831 </tr> 1832 <tr> 1833 <td>MPEG-4 SP</td> 1834 <td></td> 1835 <td>REQUIRED<sup>2</sup></td> 1836 <td></td> 1837 <td>3GPP (.3gp)</td> 1838 </tr> 1839 <tr> 1840 <td>VP8<sup>3</sup></td> 1841 <td>REQUIRED<sup>2</sup></p> 1842 1843 <p>(Android 4.3+)</td> 1844 <td>REQUIRED<sup>2</sup></p> 1845 1846 <p>(Android 2.3.3+)</td> 1847 <td>See <a href="#5_2_video_encoding">section 5.2</a> and <a href="#5_3_video_decoding">5.3</a> for details</td> 1848 <td><ul> 1849 <li class="table_list">WebM (.webm) [<a href="http://www.webmproject.org/">Resources, 110</a></li> 1850 <li class="table_list">Matroska (.mkv, Android 4.0+)<sup>4</sup></li></ul></td> 1851 </tr> 1852 <tr> 1853 <td>VP9</td> 1854 <td></td> 1855 <td>REQUIRED<sup>2</sup><br> (Android 4.4+)</td> 1856 <td>See <a href="#5_3_video_decoding">section 5.3</a> for details</td> 1857 <td><ul> 1858 <li class="table_list">WebM (.webm) [<a href="http://www.webmproject.org/">Resources, 110</a>]</li> 1859 <li class="table_list">Matroska (.mkv, Android 4.0+)<sup>4</sup></li></ul></td> 1860 </tr> 1861 </table> 1862 1863 1864 <p class="table_footnote">1 Required for device implementations that include camera hardware and define 1865 android.hardware.camera or android.hardware.camera.front.</p> 1866 1867 <p class="table_footnote">2 Required for device implementations except Android Watch devices. </p> 1868 1869 <p class="table_footnote">3 For acceptable quality of web video streaming and video-conference services, 1870 device implementations SHOULD use a hardware VP8 codec that meets the 1871 requirements in [<a href="http://www.webmproject.org/hardware/rtc-coding-requirements/">Resources, 51</a>].</p> 1872 1873 <p class="table_footnote">4 Device implementations SHOULD support writing Matroska WebM files.</p> 1874 1875 <p class="table_footnote">5 Strongly recommended for Android Automotive, optional for Android Watch, and required for all other device types.</p> 1876 1877 <h2 id="5_2_video_encoding">5.2. Video Encoding</h2> 1878 1879 <div class="note"> 1880 <p>Video codecs are optional for Android Watch device implementations.</p> 1881 </div> 1882 1883 1884 <p>Android device implementations with H.264 codec support, MUST support Baseline 1885 Profile Level 3 and the following SD (Standard Definition) video encoding 1886 profiles and SHOULD support Main Profile Level 4 and the following HD (High 1887 Definition) video encoding profiles. Android Television devices are STRONGLY 1888 RECOMMENDED to encode HD 1080p video at 30 fps.</p> 1889 <table> 1890 <tr> 1891 <th></th> 1892 <th>SD (Low quality)</th> 1893 <th>SD (High quality)</th> 1894 <th>HD 720p1</th> 1895 <th>HD 1080p1</th> 1896 </tr> 1897 <tr> 1898 <th>Video resolution</th> 1899 <td>320 x 240 px</td> 1900 <td>720 x 480 px</td> 1901 <td>1280 x 720 px</td> 1902 <td>1920 x 1080 px</td> 1903 </tr> 1904 <tr> 1905 <th>Video frame rate</th> 1906 <td>20 fps</td> 1907 <td>30 fps</td> 1908 <td>30 fps</td> 1909 <td>30 fps</td> 1910 </tr> 1911 <tr> 1912 <th>Video bitrate</th> 1913 <td>384 Kbps</td> 1914 <td>2 Mbps</td> 1915 <td>4 Mbps</td> 1916 <td>10 Mbps</td> 1917 </tr> 1918 </table> 1919 1920 1921 <p class="table_footnote">1 When supported by hardware, but STRONGLY RECOMMENDED for Android Television 1922 devices.</p> 1923 1924 <p>Android device implementations with VP8 codec support MUST support the SD video 1925 encoding profiles and SHOULD support the following HD (High Definition) video 1926 encoding profiles.</p> 1927 <table> 1928 <tr> 1929 <th></th> 1930 <th>SD (Low quality)</th> 1931 <th>SD (High quality)</th> 1932 <th>HD 720p1</th> 1933 <th>HD 1080p1</th> 1934 </tr> 1935 <tr> 1936 <th>Video resolution</th> 1937 <td>320 x 180 px</td> 1938 <td>640 x 360 px</td> 1939 <td>1280 x 720 px</td> 1940 <td>1920 x 1080 px</td> 1941 </tr> 1942 <tr> 1943 <th>Video frame rate</th> 1944 <td>30 fps</td> 1945 <td>30 fps</td> 1946 <td>30 fps</td> 1947 <td>30 fps</td> 1948 </tr> 1949 <tr> 1950 <th>Video bitrate</th> 1951 <td>800 Kbps </td> 1952 <td>2 Mbps</td> 1953 <td>4 Mbps</td> 1954 <td>10 Mbps</td> 1955 </tr> 1956 </table> 1957 1958 <p class="table_footnote">1 When supported by hardware.</p> 1959 1960 <h2 id="5_3_video_decoding">5.3. Video Decoding</h2> 1961 1962 <div class="note"> 1963 <p>Video codecs are optional for Android Watch device implementations.</p> 1964 </div> 1965 1966 1967 <p>Device implementations MUST support dynamic video resolution switching within 1968 the same stream for all VP8, VP9, H.264, and H.265 codecs exposed to developers 1969 through the standard Android APIs.</p> 1970 1971 <p>Android device implementations with H.264 decoders, MUST support Baseline 1972 Profile Level 3 and the following SD video decoding profiles and SHOULD support 1973 the HD decoding profiles. Android Television devices MUST support High Profile 1974 Level 4.2 and the HD 1080p decoding profile.</p> 1975 <table> 1976 <tr> 1977 <th></th> 1978 <th>SD (Low quality)</th> 1979 <th>SD (High quality)</th> 1980 <th>HD 720p1</th> 1981 <th>HD 1080p1</th> 1982 </tr> 1983 <tr> 1984 <th>Video resolution</th> 1985 <td>320 x 240 px</td> 1986 <td>720 x 480 px</td> 1987 <td>1280 x 720 px</td> 1988 <td>1920 x 1080 px</td> 1989 </tr> 1990 <tr> 1991 <th>Video frame rate</th> 1992 <td>30 fps</td> 1993 <td>30 fps</td> 1994 <td>30 fps / 60 fps2</td> 1995 <td>30 fps / 60 fps2</td> 1996 </tr> 1997 <tr> 1998 <th>Video bitrate</th> 1999 <td>800 Kbps </td> 2000 <td>2 Mbps</td> 2001 <td>8 Mbps</td> 2002 <td>20 Mbps</td> 2003 </tr> 2004 </table> 2005 2006 2007 <p class="table_footnote">1 Required for Android Television device implementations, but for other device 2008 types only when supported by hardware.</p> 2009 2010 <p class="table_footnote">2 Required for Android Television device implementations.</p> 2011 2012 <p>Android device implementations when supporting VP8 codec as described in <a href="#5_1_3_video_codecs">section 5.1.3</a>, MUST support the following SD decoding profiles and SHOULD support the HD 2013 decoding profiles. Android Television devices MUST support the HD 1080p 2014 decoding profile. </p> 2015 <table> 2016 <tr> 2017 <th></th> 2018 <th>SD (Low quality)</th> 2019 <th>SD (High quality)</th> 2020 <th>HD 720p1</th> 2021 <th>HD 1080p1</th> 2022 </tr> 2023 <tr> 2024 <th>Video resolution</th> 2025 <td>320 x 180 px</td> 2026 <td>640 x 360 px</td> 2027 <td>1280 x 720 px</td> 2028 <td>1920 x 1080 px</td> 2029 </tr> 2030 <tr> 2031 <th>Video frame rate</th> 2032 <td>30 fps</td> 2033 <td>30 fps</td> 2034 <td>30 fps / 60 fps2</td> 2035 <td>30 / 60 fps2</td> 2036 </tr> 2037 <tr> 2038 <th>Video bitrate</th> 2039 <td>800 Kbps </td> 2040 <td>2 Mbps</td> 2041 <td>8 Mbps</td> 2042 <td>20 Mbps</td> 2043 </tr> 2044 </table> 2045 2046 2047 <p class="table_footnote">1 Required for Android Television device implementations, but for other type of 2048 devices only when supported by hardware.</p> 2049 2050 <p class="table_footnote">2 Required for Android Television device implementations.</p> 2051 2052 <p>Android device implementations, when supporting VP9 codec as described in <a href="#5_1_3_video_codecs">section 5.1.3</a>, MUST support the following SD video decoding profiles and SHOULD support the 2053 HD decoding profiles. Android Television devices are STRONGLY RECOMMENDED to 2054 support the HD 1080p decoding profile and SHOULD support the UHD decoding 2055 profile. When the UHD video decoding profile is supported, it MUST support 8 2056 bit color depth.</p> 2057 <table> 2058 <tr> 2059 <th></th> 2060 <th>SD (Low quality)</th> 2061 <th>SD (High quality)</th> 2062 <th>HD 720p 1</th> 2063 <th>HD 1080p 2</th> 2064 <th>UHD 2</th> 2065 </tr> 2066 <tr> 2067 <th>Video resolution</th> 2068 <td>320 x 180 px</td> 2069 <td>640 x 360 px</td> 2070 <td>1280 x 720 px</td> 2071 <td>1920 x 1080 px</td> 2072 <td>3840 x 2160 px</td> 2073 </tr> 2074 <tr> 2075 <th>Video frame rate</th> 2076 <td>30 fps</td> 2077 <td>30 fps</td> 2078 <td>30 fps</td> 2079 <td>30 fps</td> 2080 <td>30 fps</td> 2081 </tr> 2082 <tr> 2083 <th>Video bitrate</th> 2084 <td>600 Kbps </td> 2085 <td>1.6 Mbps</td> 2086 <td>4 Mbps</td> 2087 <td>10 Mbps</td> 2088 <td>20 Mbps</td> 2089 </tr> 2090 </table> 2091 2092 2093 <p class="table_footnote">1 Required for Android Television device implementations, but for other type of 2094 devices only when supported by hardware.</p> 2095 2096 <p class="table_footnote">2 STRONGLY RECOMMENDED for Android Television device implementations when 2097 supported by hardware.</p> 2098 2099 <p>Android device implementations, when supporting H.265 codec as described in 2100 <a href="#5_1_3_video_codecs">section 5.1.3</a>, MUST support the Main Profile Level 3 Main tier 2101 and the following SD video decoding profiles and SHOULD support the HD decoding profiles. Android 2102 Television devices SHOULD support Main10 Level 5 Main Tier profile and the UHD decoding profile. 2103 Android Television devices are STRONGLY RECOMMENDED to support the HD 1080p decoding profile. 2104 If the HD 1080p decoding profile is supported, it MUST support the Main Profile Level 2105 4.1 Main tier</p> 2106 <table> 2107 <tr> 2108 <th></th> 2109 <th>SD (Low quality)</th> 2110 <th>SD (High quality)</th> 2111 <th>HD 720p </strong>1 </td> 2112 <th>HD 1080p </strong>2 </td> 2113 <th>UHD </strong>2</td> 2114 </tr> 2115 <tr> 2116 <th>Video resolution</th> 2117 <td>352 x 288 px</td> 2118 <td>640 x 360 px</td> 2119 <td>1280 x 720 px</td> 2120 <td>1920 x 1080 px</td> 2121 <td>3840 x 2160 px</td> 2122 </tr> 2123 <tr> 2124 <th>Video frame rate</th> 2125 <td>30 fps</td> 2126 <td>30 fps</td> 2127 <td>30 fps</td> 2128 <td>30 fps</td> 2129 <td>30 fps</td> 2130 </tr> 2131 <tr> 2132 <th>Video bitrate</th> 2133 <td>600 Kbps </td> 2134 <td>1.6 Mbps</td> 2135 <td>4 Mbps</td> 2136 <td>10 Mbps</td> 2137 <td>20 Mbps</td> 2138 </tr> 2139 </table> 2140 2141 2142 <p class="table_footnote">1 Required for Android Television device implementation, but for other type of 2143 devices only when supported by hardware.</p> 2144 2145 <p class="table_footnote">2 STRONGLY RECOMMENDED for Android Television device implementations when supported by 2146 hardware.</p> 2147 2148 <h2 id="5_4_audio_recording">5.4. Audio Recording</h2> 2149 2150 2151 <p>While some of the requirements outlined in this section are stated as SHOULD 2152 since Android 4.3, the Compatibility Definition for a future version is planned 2153 to change these to MUST. Existing and new Android devices are <strong>very strongly encouraged</strong> to meet these requirements, or they will not be able to attain Android 2154 compatibility when upgraded to the future version.</p> 2155 2156 <h3 id="5_4_1_raw_audio_capture">5.4.1. Raw Audio Capture</h3> 2157 2158 2159 <p>Device implementations that declare android.hardware.microphone MUST allow 2160 capture of raw audio content with the following characteristics:</p> 2161 2162 <ul> 2163 <li><strong>Format</strong>: Linear PCM, 16-bit 2164 <li><strong>Sampling rates</strong>: 8000, 11025, 16000, 44100 2165 <li><strong>Channels</strong>: Mono 2166 </ul> 2167 2168 <p>Device implementations that declare android.hardware.microphone SHOULD allow 2169 capture of raw audio content with the following characteristics:</p> 2170 2171 <ul> 2172 <li><strong>Format</strong>: Linear PCM, 16-bit 2173 <li><strong>Sampling rates</strong>: 22050, 48000 2174 <li><strong>Channels</strong>: Stereo 2175 </ul> 2176 2177 <h3 id="5_4_2_capture_for_voice_recognition">5.4.2. Capture for Voice Recognition</h3> 2178 2179 2180 <p>In addition to the above recording specifications, when an application has 2181 started recording an audio stream using the 2182 android.media.MediaRecorder.AudioSource.VOICE_RECOGNITION audio source:</p> 2183 2184 <ul> 2185 <li>The device SHOULD exhibit approximately flat amplitude versus frequency 2186 characteristics: specifically, 3 dB, from 100 Hz to 4000 Hz. 2187 <li>Audio input sensitivity SHOULD be set such that a 90 dB sound power level (SPL) 2188 source at 1000 Hz yields RMS of 2500 for 16-bit samples. 2189 <li>PCM amplitude levels SHOULD linearly track input SPL changes over at least a 30 2190 dB range from -18 dB to +12 dB re 90 dB SPL at the microphone. 2191 <li>Total harmonic distortion SHOULD be less than 1% for 1Khz at 90 dB SPL input 2192 level at the microphone. 2193 <li>Noise reduction processing, if present, MUST be disabled. 2194 <li>Automatic gain control, if present, MUST be disabled 2195 </ul> 2196 2197 <p>If the platform supports noise suppression technologies tuned for speech 2198 recognition, the effect MUST be controllable from the 2199 android.media.audiofx.NoiseSuppressor API. Moreover, the UUID field for the 2200 noise suppressor’s effect descriptor MUST uniquely identify each implementation 2201 of the noise suppression technology.</p> 2202 2203 <h3 id="5_4_3_capture_for_rerouting_of_playback">5.4.3. Capture for Rerouting of Playback</h3> 2204 2205 2206 <p>The android.media.MediaRecorder.AudioSource class includes the REMOTE_SUBMIX 2207 audio source. Devices that declare android.hardware.audio.output MUST properly 2208 implement the REMOTE_SUBMIX audio source so that when an application uses the 2209 android.media.AudioRecord API to record from this audio source, it can capture 2210 a mix of all audio streams except for the following:</p> 2211 2212 <ul> 2213 <li>STREAM_RING 2214 <li>STREAM_ALARM 2215 <li>STREAM_NOTIFICATION 2216 </ul> 2217 2218 <h2 id="5_5_audio_playback">5.5. Audio Playback</h2> 2219 2220 2221 <p>Device implementations that declare android.hardware.audio.output MUST conform 2222 to the requirements in this section.</p> 2223 2224 <h3 id="5_5_1_raw_audio_playback">5.5.1. Raw Audio Playback</h3> 2225 2226 2227 <p>The device MUST allow playback of raw audio content with the following 2228 characteristics:</p> 2229 2230 <ul> 2231 <li><strong>Format</strong>: Linear PCM, 16-bit</li> 2232 <li><strong>Sampling rates</strong>: 8000, 11025, 16000, 22050, 32000, 44100</li> 2233 <li><strong>Channels</strong>: Mono, Stereo</li> 2234 </ul> 2235 2236 <p>The device SHOULD allow playback of raw audio content with the following 2237 characteristics:</p> 2238 2239 <ul> 2240 <li><strong>Sampling rates</strong>: 24000, 48000</li> 2241 </ul> 2242 2243 <h3 id="5_5_2_audio_effects">5.5.2. Audio Effects</h3> 2244 2245 2246 <p>Android provides an API for audio effects for device implementations [<a href="http://developer.android.com/reference/android/media/audiofx/AudioEffect.html">Resources, 52</a>]. Device implementations that declare the feature 2247 android.hardware.audio.output:</p> 2248 2249 <ul> 2250 <li>MUST support the EFFECT_TYPE_EQUALIZER and EFFECT_TYPE_LOUDNESS_ENHANCER 2251 implementations controllable through the AudioEffect subclasses Equalizer, 2252 LoudnessEnhancer.</li> 2253 <li>MUST support the visualizer API implementation, controllable through the 2254 Visualizer class.</li> 2255 <li>SHOULD support the EFFECT_TYPE_BASS_BOOST, EFFECT_TYPE_ENV_REVERB, 2256 EFFECT_TYPE_PRESET_REVERB, and EFFECT_TYPE_VIRTUALIZER implementations 2257 controllable through the AudioEffect sub-classes BassBoost, 2258 EnvironmentalReverb, PresetReverb, and Virtualizer.</li> 2259 </ul> 2260 2261 <h3 id="5_5_3_audio_output_volume">5.5.3. Audio Output Volume</h3> 2262 2263 2264 <p>Android Television device implementations MUST include support for system 2265 Master Volume and digital audio output volume attenuation on supported outputs, 2266 except for compressed audio passthrough output (where no audio decoding is done 2267 on the device).</p> 2268 2269 <h2 id="5_6_audio_latency">5.6. Audio Latency</h2> 2270 2271 2272 <p>Audio latency is the time delay as an audio signal passes through a system. 2273 Many classes of applications rely on short latencies, to achieve real-time 2274 sound effects.</p> 2275 2276 <p>For the purposes of this section, use the following definitions:</p> 2277 2278 <ul> 2279 <li><strong>output latency</strong>. The interval between when an application writes a frame of PCM-coded data and 2280 when the corresponding sound can be heard by an external listener or observed 2281 by a transducer.</li> 2282 <li><strong>cold output latency</strong>. The output latency for the first frame, when the audio output system has been 2283 idle and powered down prior to the request.</li> 2284 <li><strong>continuous output latency</strong>. The output latency for subsequent frames, after the device is playing audio.</li> 2285 <li><strong>input latency</strong>. The interval between when an external sound is presented to the device and 2286 when an application reads the corresponding frame of PCM-coded data.</li> 2287 <li><strong>cold input latency</strong>. The sum of lost input time and the input latency for the first frame, when the 2288 audio input system has been idle and powered down prior to the request.</li> 2289 <li><strong>continuous input latency</strong>. The input latency for subsequent frames, while the device is capturing audio.</li> 2290 <li><strong>cold output jitter</strong>. The variance among separate measurements of cold output latency values.</li> 2291 <li><strong>cold input jitter</strong>. The variance among separate measurements of cold input latency values.</li> 2292 <li><strong>continuous round-trip latency</strong>. The sum of continuous input latency plus continuous output latency plus 5 2293 milliseconds.</li> 2294 <li><strong>OpenSL ES PCM buffer queue API</strong>. The set of PCM-related OpenSL ES APIs within Android NDK; see 2295 NDK_root/docs/opensles/index.html.</li> 2296 </ul> 2297 2298 <p>Device implementations that declare android.hardware.audio.output SHOULD meet 2299 or exceed these audio output requirements:</p> 2300 2301 <ul> 2302 <li>cold output latency of 100 milliseconds or less</li> 2303 <li>continuous output latency of 45 milliseconds or less</li> 2304 <li>minimize the cold output jitter</li> 2305 </ul> 2306 2307 <p>If a device implementation meets the requirements of this section after any 2308 initial calibration when using the OpenSL ES PCM buffer queue API, for 2309 continuous output latency and cold output latency over at least one supported 2310 audio output device, it MAY report support for low-latency audio, by reporting 2311 the feature android.hardware.audio.low_latency via the 2312 android.content.pm.PackageManager class [<a href="http://developer.android.com/reference/android/content/pm/PackageManager.html">Resources, 53</a>]. Conversely, if the device implementation does not meet these requirements it 2313 MUST NOT report support for low-latency audio.</p> 2314 2315 <p>Device implementations that include android.hardware.microphone SHOULD meet 2316 these input audio requirements:</p> 2317 2318 <ul> 2319 <li>cold input latency of 100 milliseconds or less</li> 2320 <li>continuous input latency of 30 milliseconds or less</li> 2321 <li>continuous round-trip latency of 50 milliseconds or less</li> 2322 <li>minimize the cold input jitter</li> 2323 </ul> 2324 2325 <h2 id="5_7_network_protocols">5.7. Network Protocols</h2> 2326 2327 2328 <p>Devices MUST support the media network protocols for audio and video playback 2329 as specified in the Android SDK documentation [<a href="http://developer.android.com/guide/appendix/media-formats.html">Resources, 50</a>]. Specifically, devices MUST support the following media network protocols:</p> 2330 2331 <ul> 2332 <li>RTSP (RTP, SDP)</li> 2333 <li>HTTP(S) progressive streaming</li> 2334 <li>HTTP(S) Live Streaming draft protocol, Version 3 [<a href="http://tools.ietf.org/html/draft-pantos-http-live-streaming-03">Resources, 54</a>]</li> 2335 </ul> 2336 2337 <h2 id="5_8_secure_media">5.8. Secure Media</h2> 2338 2339 2340 <p>Device implementations that support secure video output and are capable of 2341 supporting secure surfaces MUST declare support for Display.FLAG_SECURE. Device 2342 implementations that declare support for Display.FLAG_SECURE, if they support a 2343 wireless display protocol, MUST secure the link with a cryptographically strong 2344 mechanism such as HDCP 2.x or higher for Miracast wireless displays. Similarly 2345 if they support a wired external display, the device implementations MUST 2346 support HDCP 1.2 or higher. Android Television device implementations MUST 2347 support HDCP 2.2 for devices supporting 4K resolution and HDCP 1.4 or above for 2348 lower resolutions. The upstream Android open source implementation includes 2349 support for wireless (Miracast) and wired (HDMI) displays that satisfies this 2350 requirement.</p> 2351 2352 <h1 id="6_developer_tools_and_options_compatibility">6. Developer Tools and Options Compatibility</h1> 2353 2354 2355 <h2 id="6_1_developer_tools">6.1. Developer Tools</h2> 2356 2357 2358 <p>Device implementations MUST support the Android Developer Tools provided in the 2359 Android SDK. Android compatible devices MUST be compatible with:</p> 2360 2361 <ul> 2362 <li><strong>Android Debug Bridge (adb)</strong> [<a href="http://developer.android.com/tools/help/adb.html">Resources, 55</a>]</li> 2363 </ul> 2364 2365 <p>Device implementations MUST support all adb functions as documented in the 2366 Android SDK including dumpsys [<a href="https://source.android.com/devices/input/diagnostics.html">Resources, 56</a>]. The device-side adb daemon MUST be inactive by default and there MUST be a 2367 user-accessible mechanism to turn on the Android Debug Bridge. If a device 2368 implementation omits USB peripheral mode, it MUST implement the Android Debug 2369 Bridge via local-area network (such as Ethernet or 802.11). </p> 2370 2371 <p>Android includes support for secure adb. Secure adb enables adb on known 2372 authenticated hosts. Device implementations MUST support secure adb.</p> 2373 2374 <ul> 2375 <li><strong>Dalvik Debug Monitor Service (ddms)</strong> [<a href="http://developer.android.com/tools/debugging/ddms.html">Resources, 57</a>]</li> 2376 </ul> 2377 2378 <p>Device implementations MUST support all ddms features as documented in the 2379 Android SDK. As ddms uses adb, support for ddms SHOULD be inactive by default, 2380 but MUST be supported whenever the user has activated the Android Debug Bridge, 2381 as above.</p> 2382 2383 <ul> 2384 <li><strong>Monkey</strong> [<a href="http://developer.android.com/tools/help/monkey.html">Resources, 58</a>]</li> 2385 </ul> 2386 2387 <p>Device implementations MUST include the Monkey framework, and make it available 2388 for applications to use.</p> 2389 2390 <ul> 2391 <li><strong>SysTrace</strong> [<a href="http://developer.android.com/tools/help/systrace.html">Resources, 59</a>]</li> 2392 </ul> 2393 2394 <p>Device implementations MUST support systrace tool as documented in the Android 2395 SDK. Systrace must be inactive by default, and there MUST be a user-accessible 2396 mechanism to turn on Systrace.</p> 2397 2398 <p>Most Linux-based systems and Apple Macintosh systems recognize Android devices 2399 using the standard Android SDK tools, without additional support; however 2400 Microsoft Windows systems typically require a driver for new Android devices. 2401 (For instance, new vendor IDs and sometimes new device IDs require custom USB 2402 drivers for Windows systems.) If a device implementation is unrecognized by the 2403 adb tool as provided in the standard Android SDK, device implementers MUST 2404 provide Windows drivers allowing developers to connect to the device using the 2405 adb protocol. These drivers MUST be provided for Windows XP, Windows Vista, 2406 Windows 7, Windows 8, and Windows 9 in both 32-bit and 64-bit versions.</p> 2407 2408 <h2 id="6_2_developer_options">6.2. Developer Options</h2> 2409 2410 2411 <p>Android includes support for developers to configure application 2412 development-related settings. Device implementations MUST honor the 2413 android.settings.APPLICATION_DEVELOPMENT_SETTINGS intent to show application 2414 development-related settings [<a href="http://developer.android.com/reference/android/provider/Settings.html#ACTION_APPLICATION_DEVELOPMENT_SETTINGS">Resources, 60</a>]. The upstream Android implementation hides the Developer Options menu by 2415 default and enables users to launch Developer Options after pressing seven (7) 2416 times on the <strong>Settings</strong> > <strong>About Device</strong> > <strong>Build Number</strong> menu item. Device implementations MUST provide a consistent experience for 2417 Developer Options. Specifically, device implementations MUST hide Developer 2418 Options by default and MUST provide a mechanism to enable Developer Options 2419 that is consistent with the upstream Android implementation.</p> 2420 2421 <h1 id="7_hardware_compatibility">7. Hardware Compatibility</h1> 2422 2423 2424 <p>If a device includes a particular hardware component that has a corresponding 2425 API for third-party developers, the device implementation MUST implement that 2426 API as described in the Android SDK documentation. If an API in the SDK 2427 interacts with a hardware component that is stated to be optional and the 2428 device implementation does not possess that component:</p> 2429 2430 <ul> 2431 <li>Complete class definitions (as documented by the SDK) for the component APIs 2432 MUST still be presented. 2433 <li>The API’s behaviors MUST be implemented as no-ops in some reasonable fashion. 2434 <li>API methods MUST return null values where permitted by the SDK documentation. 2435 <li>API methods MUST return no-op implementations of classes where null values are 2436 not permitted by the SDK documentation. 2437 <li>API methods MUST NOT throw exceptions not documented by the SDK documentation. 2438 </ul> 2439 2440 <p>A typical example of a scenario where these requirements apply is the telephony 2441 API: even on non-phone devices, these APIs must be implemented as reasonable 2442 no-ops.</p> 2443 2444 <p>Device implementations MUST consistently report accurate hardware configuration 2445 information via the getSystemAvailableFeatures() and hasSystemFeature(String) 2446 methods on the android.content.pm.PackageManager class for the same build 2447 fingerprint. [<a href="http://developer.android.com/reference/android/content/pm/PackageManager.html">Resources, 53]</a></p> 2448 2449 <h2 id="7_1_display_and_graphics">7.1. Display and Graphics</h2> 2450 2451 2452 <p>Android includes facilities that automatically adjust application assets and UI 2453 layouts appropriately for the device, to ensure that third-party applications 2454 run well on a variety of hardware configurations [<a href="http://developer.android.com/guide/practices/screens_support.html">Resources, 61</a>]. Devices MUST properly implement these APIs and behaviors, as detailed in 2455 this section.</p> 2456 2457 <p>The units referenced by the requirements in this section are defined as 2458 follows:</p> 2459 2460 <ul> 2461 <li><strong>physical diagonal size</strong>. The distance in inches between two opposing corners of the illuminated portion 2462 of the display.</li> 2463 <li><strong>dots per inch (dpi)</strong>. The number of pixels encompassed by a linear horizontal or vertical span of 2464 1”. Where dpi values are listed, both horizontal and vertical dpi must fall 2465 within the range.</li> 2466 <li><strong>aspect ratio</strong>. The ratio of the pixels of the longer dimension 2467 to the shorter dimension of the screen. For example, a display of 480x854 pixels 2468 would be 854/480 = 1.779, or roughly “16:9”.</li> 2469 <li><strong>density-independent pixel (dp)</strong> The virtual pixel unit normalized to a 160 dpi screen, calculated as: pixels = 2470 dps * (density/160).</li> 2471 </ul> 2472 2473 <h3 id="7_1_1_screen_configuration">7.1.1. Screen Configuration</h3> 2474 2475 2476 <h4 id="7_1_1_1_screen_size">7.1.1.1. Screen Size</h4> 2477 2478 <div class="note"> 2479 <p>Android Watch devices (detailed in <a href="#2_device_types">section 2</a>) MAY have smaller screen sizes as described in this section.</p> 2480 </div> 2481 2482 <p>The Android UI framework supports a variety of different screen sizes, and 2483 allows applications to query the device screen size (aka “screen layout") via 2484 android.content.res.Configuration.screenLayout with the SCREENLAYOUT_SIZE_MASK. 2485 Device implementations MUST report the correct screen size as defined in the 2486 Android SDK documentation [<a href="http://developer.android.com/guide/practices/screens_support.html">Resources, 61</a>] and determined by the upstream Android platform. Specifically, device 2487 implementations MUST report the correct screen size according to the following 2488 logical density-independent pixel (dp) screen dimensions.</p> 2489 2490 <ul> 2491 <li>Devices MUST have screen sizes of at least 426 dp x 320 dp (‘small’), unless it 2492 is an Android Watch device.</li> 2493 <li>Devices that report screen size ‘normal’ MUST have screen sizes of at least 480 2494 dp x 320 dp.</li> 2495 <li>Devices that report screen size ‘large’ MUST have screen sizes of at least 640 2496 dp x 480 dp.</li> 2497 <li>Devices that report screen size ‘xlarge’ MUST have screen sizes of at least 960 2498 dp x 720 dp.</li> 2499 </ul> 2500 2501 <p>In addition, </p> 2502 2503 <ul> 2504 <li>Android Watch devices MUST have a screen with the physical diagonal size in the 2505 range from 1.1 to 2.5 inches.</li> 2506 <li>Other types of Android device implementations, with a physically integrated 2507 screen, MUST have a screen at least 2.5 inches in physical diagonal size.</li> 2508 </ul> 2509 2510 <p>Devices MUST NOT change their reported screen size at any time.</p> 2511 2512 <p>Applications optionally indicate which screen sizes they support via the 2513 <supports-screens> attribute in the AndroidManifest.xml file. Device 2514 implementations MUST correctly honor applications' stated support for small, 2515 normal, large, and xlarge screens, as described in the Android SDK 2516 documentation.</p> 2517 2518 <h4 id="7_1_1_2_screen_aspect_ratio">7.1.1.2. Screen Aspect Ratio</h4> 2519 2520 <div class="note"> 2521 <p>Android Watch devices MAY have an aspect ratio of 1.0 (1:1).</p> 2522 </div> 2523 2524 2525 <p>The screen aspect ratio MUST be a value from 1.3333 (4:3) to 1.86 (roughly 2526 16:9), but Android Watch devices MAY have an aspect ratio of 1.0 (1:1) because 2527 such a device implementation will use a UI_MODE_TYPE_WATCH as the 2528 android.content.res.Configuration.uiMode.</p> 2529 2530 <h4 id="7_1_1_3_screen_density">7.1.1.3. Screen Density</h4> 2531 2532 2533 <p>The Android UI framework defines a set of standard logical densities to help 2534 application developers target application resources. Device implementations 2535 MUST report only one of the following logical Android framework densities 2536 through the android.util.DisplayMetrics APIs, and MUST execute applications at 2537 this standard density and MUST NOT change the value at at any time for the 2538 default display.</p> 2539 2540 <ul> 2541 <li>120 dpi (ldpi)</li> 2542 <li>160 dpi (mdpi)</li> 2543 <li>213 dpi (tvdpi)</li> 2544 <li>240 dpi (hdpi)</li> 2545 <li>280 dpi (280dpi)</li> 2546 <li>320 dpi (xhdpi)</li> 2547 <li>400 dpi (400dpi)</li> 2548 <li>480 dpi (xxhdpi)</li> 2549 <li>560 dpi (560dpi)</li> 2550 <li>640 dpi (xxxhdpi)</li> 2551 </ul> 2552 2553 <p>Device implementations SHOULD define the standard Android framework density 2554 that is numerically closest to the physical density of the screen, unless that 2555 logical density pushes the reported screen size below the minimum supported. If 2556 the standard Android framework density that is numerically closest to the 2557 physical density results in a screen size that is smaller than the smallest 2558 supported compatible screen size (320 dp width), device implementations SHOULD 2559 report the next lowest standard Android framework density.</p> 2560 2561 <h3 id="7_1_2_display_metrics">7.1.2. Display Metrics</h3> 2562 2563 2564 <p>Device implementations MUST report correct values for all display metrics 2565 defined in android.util.DisplayMetrics [<a href="http://developer.android.com/reference/android/util/DisplayMetrics.html">Resources, 62</a>] and MUST report the same values regardless of whether the embedded or 2566 external screen is used as the default display.</p> 2567 2568 <h3 id="7_1_3_screen_orientation">7.1.3. Screen Orientation</h3> 2569 2570 2571 <p>Devices MUST report which screen orientations they support 2572 (android.hardware.screen.portrait and/or android.hardware.screen.landscape) and 2573 MUST report at least one supported orientation. For example, a device with a 2574 fixed orientation landscape screen, such as a television or laptop, SHOULD only 2575 report android.hardware.screen.landscape.</p> 2576 2577 <p>Devices that report both screen orientations MUST support dynamic orientation 2578 by applications to either portrait or landscape screen orientation. That is, 2579 the device must respect the application’s request for a specific screen 2580 orientation. Device implementations MAY select either portrait or landscape 2581 orientation as the default.</p> 2582 2583 <p>Devices MUST report the correct value for the device’s current orientation, 2584 whenever queried via the android.content.res.Configuration.orientation, 2585 android.view.Display.getOrientation(), or other APIs.</p> 2586 2587 <p>Devices MUST NOT change the reported screen size or density when changing 2588 orientation.</p> 2589 2590 <h3 id="7_1_4_2d_and_3d_graphics_acceleration">7.1.4. 2D and 3D Graphics Acceleration</h3> 2591 2592 2593 <p>Device implementations MUST support both OpenGL ES 1.0 and 2.0, as embodied and 2594 detailed in the Android SDK documentations. Device implementations SHOULD 2595 support OpenGL ES 3.0 or 3.1 on devices capable of supporting it. Device 2596 implementations MUST also support Android RenderScript, as detailed in the 2597 Android SDK documentation [<a href="http://developer.android.com/guide/topics/renderscript/">Resources, 63</a>].</p> 2598 2599 <p>Device implementations MUST also correctly identify themselves as supporting 2600 OpenGL ES 1.0, OpenGL ES 2.0, OpenGL ES 3.0 or OpenGL 3.1. That is:</p> 2601 2602 <ul> 2603 <li>The managed APIs (such as via the GLES10.getString() method) MUST report support 2604 for OpenGL ES 1.0 and OpenGL ES 2.0.</li> 2605 <li>The native C/C++ OpenGL APIs (APIs available to apps via libGLES_v1CM.so, 2606 libGLES_v2.so, or libEGL.so) MUST report support for OpenGL ES 1.0 and OpenGL 2607 ES 2.0.</li> 2608 <li>Device implementations that declare support for OpenGL ES 3.0 or 3.1 MUST 2609 support the corresponding managed APIs and include support for native C/C++ 2610 APIs. On device implementations that declare support for OpenGL ES 3.0 or 3.1, 2611 libGLESv2.so MUST export the corresponding function symbols in addition to the 2612 OpenGL ES 2.0 function symbols.</li> 2613 </ul> 2614 2615 <p>In addition to OpenGL ES 3.1, Android provides an extension pack with Java 2616 interfaces [<a href="https://developer.android.com/reference/android/opengl/GLES31Ext.html">Resources, 64</a>] and native support for advanced graphics functionality such as tessellation 2617 and the ASTC texture compression format. Android device implementations MAY 2618 support this extension pack, and—only if fully implemented—MUST identify the 2619 support through the android.hardware.opengles.aep feature flag.</p> 2620 2621 <p>Also, device implementations MAY implement any desired OpenGL ES extensions. 2622 However, device implementations MUST report via the OpenGL ES managed and 2623 native APIs all extension strings that they do support, and conversely MUST NOT 2624 report extension strings that they do not support.</p> 2625 2626 <p>Note that Android includes support for applications to optionally specify that 2627 they require specific OpenGL texture compression formats. These formats are 2628 typically vendor-specific. Device implementations are not required by Android 2629 to implement any specific texture compression format. However, they SHOULD 2630 accurately report any texture compression formats that they do support, via the 2631 getString() method in the OpenGL API.</p> 2632 2633 <p>Android includes a mechanism for applications to declare that they want to 2634 enable hardware acceleration for 2D graphics at the Application, Activity, 2635 Window, or View level through the use of a manifest tag 2636 android:hardwareAccelerated or direct API calls [<a href="http://developer.android.com/guide/topics/graphics/hardware-accel.html">Resources, 65</a>].</p> 2637 2638 <p>Device implementations MUST enable hardware acceleration by default, and MUST 2639 disable hardware acceleration if the developer so requests by setting 2640 android:hardwareAccelerated="false” or disabling hardware acceleration directly 2641 through the Android View APIs.</p> 2642 2643 <p>In addition, device implementations MUST exhibit behavior consistent with the 2644 Android SDK documentation on hardware acceleration [<a href="http://developer.android.com/guide/topics/graphics/hardware-accel.html">Resources, 65</a>].</p> 2645 2646 <p>Android includes a TextureView object that lets developers directly integrate 2647 hardware-accelerated OpenGL ES textures as rendering targets in a UI hierarchy. 2648 Device implementations MUST support the TextureView API, and MUST exhibit 2649 consistent behavior with the upstream Android implementation.</p> 2650 2651 <p>Android includes support for EGL_ANDROID_RECORDABLE, an EGLConfig attribute 2652 that indicates whether the EGLConfig supports rendering to an ANativeWindow 2653 that records images to a video. Device implementations MUST support 2654 EGL_ANDROID_RECORDABLE extension [<a href="https://www.khronos.org/registry/egl/extensions/ANDROID/EGL_ANDROID_recordable.txt">Resources, 66</a>].</p> 2655 2656 <h3 id="7_1_5_legacy_application_compatibility_mode">7.1.5. Legacy Application Compatibility Mode</h3> 2657 2658 2659 <p>Android specifies a “compatibility mode” in which the framework operates in a 2660 'normal' screen size equivalent (320dp width) mode for the benefit of legacy 2661 applications not developed for old versions of Android that pre-date 2662 screen-size independence.</p> 2663 2664 <ul> 2665 <li>Android Automotive does not support legacy compatibility mode.</li> 2666 <li>All other device implementations MUST include support for legacy application 2667 compatibility mode as implemented by the upstream Android open source code. That 2668 is, device implementations MUST NOT alter the triggers or thresholds at which 2669 compatibility mode is activated, and MUST NOT alter the behavior of the 2670 compatibility mode itself.</li> 2671 </ul> 2672 2673 <h3 id="7_1_6_screen_technology">7.1.6. Screen Technology</h3> 2674 2675 2676 <p>The Android platform includes APIs that allow applications to render rich 2677 graphics to the display. Devices MUST support all of these APIs as defined by 2678 the Android SDK unless specifically allowed in this document. </p> 2679 2680 <ul> 2681 <li>Devices MUST support displays capable of rendering 16-bit color graphics and 2682 SHOULD support displays capable of 24-bit color graphics.</li> 2683 <li>Devices MUST support displays capable of rendering animations.</li> 2684 <li>The display technology used MUST have a pixel aspect ratio (PAR) between 0.9 2685 and 1.15. That is, the pixel aspect ratio MUST be near square (1.0) with a 10 ~ 2686 15% tolerance.</li> 2687 </ul> 2688 2689 <h3 id="7_1_7_external_displays">7.1.7. Secondary Displays</h3> 2690 2691 2692 <p>Android includes support for secondary display to enable media sharing 2693 capabilities and developer APIs for accessing external displays. If a device 2694 supports an external display either via a wired, wireless, or an embedded 2695 additional display connection then the device implementation MUST implement the 2696 display manager API as described in the Android SDK documentation [<a href="http://developer.android.com/reference/android/hardware/display/DisplayManager.html">Resources, 67</a>].</p> 2697 2698 <h2 id="7_2_input_devices">7.2. Input Devices</h2> 2699 2700 <p>Devices MUST support a touchscreen or meet the requirements listed in 7.2.2 2701 for non-touch navigation.</p> 2702 2703 <h3 id="7_2_1_keyboard">7.2.1. Keyboard</h3> 2704 2705 <div class="note"> 2706 <p>Android Watch and Android Automotive implementations MAY implement a soft 2707 keyboard. All other device implementations MUST implement a soft keyboard and:</p> 2708 </div> 2709 2710 2711 <p>Device implementations:</p> 2712 2713 <ul> 2714 <li>MUST include support for the Input Management Framework (which allows 2715 third-party developers to create Input Method Editors—i.e. soft keyboard) as 2716 detailed at <a href="http://developer.android.com">http://developer.android.com</a>.</li> 2717 <li>MUST provide at least one soft keyboard implementation (regardless of whether a 2718 hard keyboard is present) except for Android Watch devices where the screen 2719 size makes it less reasonable to have a soft keyboard.</li> 2720 <li>MAY include additional soft keyboard implementations.</li> 2721 <li>MAY include a hardware keyboard.</li> 2722 <li>MUST NOT include a hardware keyboard that does not match one of the formats 2723 specified in android.content.res.Configuration.keyboard [<a href="http://developer.android.com/reference/android/content/res/Configuration.html">Resources, 68</a>] (QWERTY or 12-key).</li> 2724 </ul> 2725 2726 <h3 id="7_2_2_non-touch_navigation">7.2.2. Non-touch Navigation</h3> 2727 2728 <div class="note"> 2729 <p>Android Television devices MUST support D-pad.</p> 2730 </div> 2731 2732 <p>Device implementations:</p> 2733 2734 <ul> 2735 <li>MAY omit a non-touch navigation option (trackball, d-pad, or wheel) if the 2736 device implementation is not an Android Television device.</li> 2737 <li>MUST report the correct value for android.content.res.Configuration.navigation 2738 [<a href="http://developer.android.com/reference/android/content/res/Configuration.html">Resources, 68</a>].</li> 2739 <li>MUST provide a reasonable alternative user interface mechanism for the 2740 selection and editing of text, compatible with Input Management Engines. The 2741 upstream Android open source implementation includes a selection mechanism 2742 suitable for use with devices that lack non-touch navigation inputs.</li> 2743 </ul> 2744 2745 <h3 id="7_2_3_navigation_keys">7.2.3. Navigation Keys</h3> 2746 2747 <div class="note"> 2748 <p>The availability and visibility requirement of the Home, Recents, and Back 2749 functions differ between device types as described in this section.</p> 2750 </div> 2751 2752 <p>The Home, Recents, and Back functions (mapped to the key events KEYCODE_HOME, 2753 KEYCODE_APP_SWITCH, KEYCODE_BACK, respectively) are essential to the Android 2754 navigation paradigm and therefore:</p> 2755 2756 <ul> 2757 <li>Android Handheld device implementations MUST provide the Home, Recents, and 2758 Back functions.</li> 2759 <li>Android Television device implementations MUST provide the Home and Back 2760 functions.</li> 2761 <li>Android Watch device implementations MUST have the Home function available to 2762 the user, and the Back function except for when it is in UI_MODE_TYPE_WATCH.</li> 2763 <li>Android Automotive implementations MUST provide the Home function and MAY 2764 provide Back and Recent functions.</li> 2765 <li>All other types of device implementations MUST provide the Home and Back 2766 functions.</li> 2767 </ul> 2768 2769 <p>These functions MAY be implemented via dedicated physical buttons (such as 2770 mechanical or capacitive touch buttons), or MAY be implemented using dedicated 2771 software keys on a distinct portion of the screen, gestures, touch panel, etc. 2772 Android supports both implementations. All of these functions MUST be 2773 accessible with a single action (e.g. tap, double-click or gesture) when 2774 visible.</p> 2775 2776 <p>Recents function, if provided, MUST have a visible button or icon unless hidden 2777 together with other navigation functions in full-screen mode. This does not 2778 apply to devices upgrading from earlier Android versions that have physical 2779 buttons for navigation and no recents key.</p> 2780 2781 <p> The Home and Back functions, if provided, MUST each have a visible button or 2782 icon unless hidden together with other navigation functions in full-screen mode 2783 or when the uiMode UI_MODE_TYPE_MASK is set to UI_MODE_TYPE_WATCH.</p> 2784 2785 <p>The Menu function is deprecated in favor of action bar since Android 4.0. 2786 Therefore the new device implementations shipping with Android 5.0 and later MUST NOT 2787 implement a dedicated physical button for the Menu function. Older device 2788 implementations SHOULD NOT implement a dedicated physical button for the Menu 2789 function, but if the physical Menu button is implemented and the device is 2790 running applications with targetSdkVersion > 10, the device implementation:</p> 2791 2792 <ul> 2793 <li>MUST display the action overflow button on the action bar when it is visible 2794 and the resulting action overflow menu popup is not empty. For a device 2795 implementation launched before Android 4.4 but upgrading to Android 5.1, this 2796 is RECOMMENDED.</li> 2797 <li>MUST NOT modify the position of the action overflow popup displayed by 2798 selecting the overflow button in the action bar.</li> 2799 <li>MAY render the action overflow popup at a modified position on the screen when 2800 it is displayed by selecting the physical menu button.</li> 2801 </ul> 2802 2803 <p>For backwards compatibility, device implementations MUST make the Menu function 2804 available to applications when targetSdkVersion is less than 10, either by a physical 2805 button, a software key, or gestures. This Menu function should be presented 2806 unless hidden together with other navigation functions.</p> 2807 2808 <p>Android supports Assist action [<a href="http://developer.android.com/reference/android/content/Intent.html#ACTION_ASSIST">Resources, 69</a>]. Android device implementations except for Android Watch devices MUST make 2809 the Assist action available to the user at all times when running applications. 2810 The Assist action SHOULD be implemented as a long-press on the Home button or a 2811 swipe-up gesture on the software Home key. This function MAY be implemented via 2812 another physical button, software key, or gesture, but MUST be accessible with 2813 a single action (e.g. tap, double-click, or gesture) when other navigation keys 2814 are visible.</p> 2815 2816 <p>Device implementations MAY use a distinct portion of the screen to display the 2817 navigation keys, but if so, MUST meet these requirements:</p> 2818 2819 <ul> 2820 <li>Device implementation navigation keys MUST use a distinct portion of the 2821 screen, not available to applications, and MUST NOT obscure or otherwise 2822 interfere with the portion of the screen available to applications.</li> 2823 <li>Device implementations MUST make available a portion of the display to 2824 applications that meets the requirements defined in <a href="#7_1_1_screen_configuration">section 7.1.1</a>.</li> 2825 <li>Device implementations MUST display the navigation keys when applications do 2826 not specify a system UI mode, or specify SYSTEM_UI_FLAG_VISIBLE.</li> 2827 <li>Device implementations MUST present the navigation keys in an unobtrusive “low 2828 profile” (eg. dimmed) mode when applications specify 2829 SYSTEM_UI_FLAG_LOW_PROFILE.</li> 2830 <li>Device implementations MUST hide the navigation keys when applications specify 2831 SYSTEM_UI_FLAG_HIDE_NAVIGATION.</li> 2832 </ul> 2833 2834 <h3 id="7_2_4_touchscreen_input">7.2.4. Touchscreen Input</h3> 2835 2836 <div class="note"> 2837 <p>Android Handhelds and Watch Devices MUST support touchscreen input.</p> 2838 </div> 2839 2840 2841 <p>Device implementations SHOULD have a pointer input system of some kind (either 2842 mouse-like or touch). However, if a device implementation does not support a 2843 pointer input system, it MUST NOT report the android.hardware.touchscreen or 2844 android.hardware.faketouch feature constant. Device implementations that do 2845 include a pointer input system:</p> 2846 2847 <ul> 2848 <li>SHOULD support fully independently tracked pointers, if the device input system 2849 supports multiple pointers.</li> 2850 <li>MUST report the value of android.content.res.Configuration.touchscreen [<a href="http://developer.android.com/reference/android/content/res/Configuration.html">Resources, 68</a>] corresponding to the type of the specific touchscreen on the device.</li> 2851 </ul> 2852 2853 <p>Android includes support for a variety of touchscreens, touch pads, and fake 2854 touch input devices. Touchscreen based device implementations are associated 2855 with a display [<a href="http://source.android.com/devices/tech/input/touch-devices.html">Resources, 70</a>] such that the user has the impression of directly manipulating items on 2856 screen. Since the user is directly touching the screen, the system does not 2857 require any additional affordances to indicate the objects being manipulated. 2858 In contrast, a fake touch interface provides a user input system that 2859 approximates a subset of touchscreen capabilities. For example, a mouse or 2860 remote control that drives an on-screen cursor approximates touch, but requires 2861 the user to first point or focus then click. Numerous input devices like the 2862 mouse, trackpad, gyro-based air mouse, gyro-pointer, joystick, and multi-touch 2863 trackpad can support fake touch interactions. Android includes the feature 2864 constant android.hardware.faketouch, which corresponds to a high-fidelity 2865 non-touch (pointer-based) input device such as a mouse or trackpad that can 2866 adequately emulate touch-based input (including basic gesture support), and 2867 indicates that the device supports an emulated subset of touchscreen 2868 functionality. Device implementations that declare the fake touch feature MUST 2869 meet the fake touch requirements in <a href="#7_2_5_fake_touch_input">section 7.2.5</a>.</p> 2870 2871 <p>Device implementations MUST report the correct feature corresponding to the 2872 type of input used. Device implementations that include a touchscreen 2873 (single-touch or better) MUST report the platform feature constant 2874 android.hardware.touchscreen. Device implementations that report the platform 2875 feature constant android.hardware.touchscreen MUST also report the platform 2876 feature constant android.hardware.faketouch. Device implementations that do not 2877 include a touchscreen (and rely on a pointer device only) MUST NOT report any 2878 touchscreen feature, and MUST report only android.hardware.faketouch if they 2879 meet the fake touch requirements in <a href="#7_2_5_fake_touch_input">section 7.2.5</a>.</p> 2880 2881 <h3 id="7_2_5_fake_touch_input">7.2.5. Fake Touch Input</h3> 2882 2883 2884 <p>Device implementations that declare support for android.hardware.faketouch:</p> 2885 2886 <ul> 2887 <li>MUST report the absolute X and Y screen positions of the pointer location and 2888 display a visual pointer on the screen [<a href="http://developer.android.com/reference/android/view/MotionEvent.html">Resources, 71</a>].</li> 2889 <li>MUST report touch event with the action code that specifies the state change 2890 that occurs on the pointer going down or up on the screen [<a href="http://developer.android.com/reference/android/view/MotionEvent.html">Resources, 71</a>].</li> 2891 <li>MUST support pointer down and up on an object on the screen, which allows users 2892 to emulate tap on an object on the screen.</li> 2893 <li>MUST support pointer down, pointer up, pointer down then pointer up in the same 2894 place on an object on the screen within a time threshold, which allows users to 2895 emulate double tap on an object on the screen [<a href="http://developer.android.com/reference/android/view/MotionEvent.html">Resources, 71</a>].</li> 2896 <li>MUST support pointer down on an arbitrary point on the screen, pointer move to 2897 any other arbitrary point on the screen, followed by a pointer up, which allows 2898 users to emulate a touch drag.</li> 2899 <li>MUST support pointer down then allow users to quickly move the object to a 2900 different position on the screen and then pointer up on the screen, which 2901 allows users to fling an object on the screen.</li> 2902 </ul> 2903 2904 <p>Devices that declare support for android.hardware.faketouch.multitouch.distinct 2905 MUST meet the requirements for faketouch above, and MUST also support distinct 2906 tracking of two or more independent pointer inputs.</p> 2907 2908 <h3 id="7_2_6_game_controller_support">7.2.6. Game Controller Support</h3> 2909 2910 2911 <p>Android Television device implementations MUST support button mappings for game 2912 controllers as listed below. The upstream Android implementation includes 2913 implementation for game controllers that satisfies this requirement. </p> 2914 2915 <h4 id="7_2_6_1_button_mappings">7.2.6.1. Button Mappings</h4> 2916 2917 2918 <p>Android Television device implementations MUST support the following key 2919 mappings:</p> 2920 <table> 2921 <tr> 2922 <th>Button</th> 2923 <th>HID Usage</strong><sup>2</sup></td> 2924 <th>Android Button</th> 2925 </tr> 2926 <tr> 2927 <td><a href="http://developer.android.com/reference/android/view/KeyEvent.html#KEYCODE_BUTTON_A">A</a><sup>1</sup></td> 2928 <td>0x09 0x0001</td> 2929 <td>KEYCODE_BUTTON_A (96)</td> 2930 </tr> 2931 <tr> 2932 <td><a href="http://developer.android.com/reference/android/view/KeyEvent.html#KEYCODE_BUTTON_B">B</a><sup>1</sup></td> 2933 <td>0x09 0x0002</td> 2934 <td>KEYCODE_BUTTON_B (97)</td> 2935 </tr> 2936 <tr> 2937 <td><a href="http://developer.android.com/reference/android/view/KeyEvent.html#KEYCODE_BUTTON_X">X</a><sup>1</sup></td> 2938 <td>0x09 0x0004</td> 2939 <td>KEYCODE_BUTTON_X (99)</td> 2940 </tr> 2941 <tr> 2942 <td><a href="http://developer.android.com/reference/android/view/KeyEvent.html#KEYCODE_BUTTON_Y">Y</a><sup>1</sup></td> 2943 <td>0x09 0x0005</td> 2944 <td>KEYCODE_BUTTON_Y (100)</td> 2945 </tr> 2946 <tr> 2947 <td><a href="http://developer.android.com/reference/android/view/KeyEvent.html#KEYCODE_DPAD_UP">D-pad up</a><sup>1</sup></p> 2948 2949 <p><a href="http://developer.android.com/reference/android/view/KeyEvent.html#KEYCODE_DPAD_DOWN">D-pad down</a><sup>1</sup></td> 2950 <td>0x01 0x0039<sup>3</sup></td> 2951 <td><a href="http://developer.android.com/reference/android/view/MotionEvent.html#AXIS_HAT_Y">AXIS_HAT_Y</a><sup>4</sup></td> 2952 </tr> 2953 <tr> 2954 <td><a href="http://developer.android.com/reference/android/view/KeyEvent.html#KEYCODE_DPAD_LEFT">D-pad left</a>1</p> 2955 2956 <p><a href="http://developer.android.com/reference/android/view/KeyEvent.html#KEYCODE_DPAD_RIGHT">D-pad right</a><sup>1</sup></td> 2957 <td>0x01 0x0039<sup>3</sup></td> 2958 <td><a href="http://developer.android.com/reference/android/view/MotionEvent.html#AXIS_HAT_X">AXIS_HAT_X</a><sup>4</sup></td> 2959 </tr> 2960 <tr> 2961 <td><a href="http://developer.android.com/reference/android/view/KeyEvent.html#KEYCODE_BUTTON_L1">Left shoulder button</a><sup>1</sup></td> 2962 <td>0x09 0x0007</td> 2963 <td>KEYCODE_BUTTON_L1 (102)</td> 2964 </tr> 2965 <tr> 2966 <td><a href="http://developer.android.com/reference/android/view/KeyEvent.html#KEYCODE_BUTTON_R1">Right shoulder button</a><sup>1</sup></td> 2967 <td>0x09 0x0008</td> 2968 <td>KEYCODE_BUTTON_R1 (103)</td> 2969 </tr> 2970 <tr> 2971 <td><a href="http://developer.android.com/reference/android/view/KeyEvent.html#KEYCODE_BUTTON_THUMBL">Left stick click</a><sup>1</sup></td> 2972 <td>0x09 0x000E</td> 2973 <td>KEYCODE_BUTTON_THUMBL (106)</td> 2974 </tr> 2975 <tr> 2976 <td><a href="http://developer.android.com/reference/android/view/KeyEvent.html#KEYCODE_BUTTON_THUMBR">Right stick click</a><sup>1</sup></td> 2977 <td>0x09 0x000F</td> 2978 <td>KEYCODE_BUTTON_THUMBR (107)</td> 2979 </tr> 2980 <tr> 2981 <td><a href="http://developer.android.com/reference/android/view/KeyEvent.html#KEYCODE_HOME">Home</a><sup>1</sup></td> 2982 <td>0x0c 0x0223</td> 2983 <td>KEYCODE_HOME (3)</td> 2984 </tr> 2985 <tr> 2986 <td><a href="http://developer.android.com/reference/android/view/KeyEvent.html#KEYCODE_BACK">Back</a><sup>1</sup></td> 2987 <td>0x0c 0x0224</td> 2988 <td>KEYCODE_BACK (4)</td> 2989 </tr> 2990 </table> 2991 2992 2993 <p class="table_footnote">1 [<a href="http://developer.android.com/reference/android/view/KeyEvent.html">Resources, 72</a>]</p> 2994 2995 <p class="table_footnote">2 The above HID usages must be declared within a Game pad CA (0x01 0x0005).</p> 2996 2997 <p class="table_footnote">3 This usage must have a Logical Minimum of 0, a Logical Maximum of 7, a 2998 Physical Minimum of 0, a Physical Maximum of 315, Units in Degrees, and a 2999 Report Size of 4. The logical value is defined to be the clockwise rotation 3000 away from the vertical axis; for example, a logical value of 0 represents no 3001 rotation and the up button being pressed, while a logical value of 1 represents 3002 a rotation of 45 degrees and both the up and left keys being pressed.</p> 3003 3004 <p class="table_footnote">4 [<a href="http://developer.android.com/reference/android/view/MotionEvent.html">Resources, 71</a>]</p> 3005 3006 <table> 3007 <tr> 3008 <th>Analog Controls</strong><sup>1</sup></td> 3009 <th>HID Usage</th> 3010 <th>Android Button</th> 3011 </tr> 3012 <tr> 3013 <td><a href="http://developer.android.com/reference/android/view/MotionEvent.html#AXIS_LTRIGGER">Left Trigger</a></td> 3014 <td>0x02 0x00C5</td> 3015 <td>AXIS_LTRIGGER </td> 3016 </tr> 3017 <tr> 3018 <td><a href="http://developer.android.com/reference/android/view/MotionEvent.html#AXIS_THROTTLE">Right Trigger</a></td> 3019 <td>0x02 0x00C4</td> 3020 <td>AXIS_RTRIGGER </td> 3021 </tr> 3022 <tr> 3023 <td><a href="http://developer.android.com/reference/android/view/MotionEvent.html#AXIS_Y">Left Joystick</a></td> 3024 <td>0x01 0x0030</p> 3025 3026 <p>0x01 0x0031</td> 3027 <td>AXIS_X</p> 3028 3029 <p>AXIS_Y</td> 3030 </tr> 3031 <tr> 3032 <td><a href="http://developer.android.com/reference/android/view/MotionEvent.html#AXIS_Z">Right Joystick</a></td> 3033 <td>0x01 0x0032</p> 3034 3035 <p>0x01 0x0035</td> 3036 <td>AXIS_Z</p> 3037 3038 <p>AXIS_RZ</td> 3039 </tr> 3040 </table> 3041 3042 3043 <p class="table_footnote">1 [<a href="http://developer.android.com/reference/android/view/MotionEvent.html">Resources, 71</a>]</p> 3044 3045 <h3 id="7_2_7_remote_control">7.2.7. Remote Control</h3> 3046 3047 3048 <p>Android Television device implementations SHOULD provide a remote control to 3049 allow users to access the TV interface. The remote control MAY be a physical 3050 remote or can be a software-based remote that is accessible from a mobile phone 3051 or tablet. The remote control MUST meet the requirements defined below.</p> 3052 3053 <ul> 3054 <li><strong>Search affordance</strong>. Device implementations MUST fire KEYCODE_SEARCH when the user invokes voice search either on the physical or software-based remote.</li> 3055 <li><strong>Navigation</strong>. All Android Television remotes MUST include Back, Home, and Select buttons and 3056 support for D-pad events [<a href="http://developer.android.com/reference/android/view/KeyEvent.html">Resources, 72</a>].</li> 3057 </ul> 3058 3059 <h2 id="7_3_sensors">7.3. Sensors</h2> 3060 3061 3062 <p>Android includes APIs for accessing a variety of sensor types. Devices 3063 implementations generally MAY omit these sensors, as provided for in the 3064 following subsections. If a device includes a particular sensor type that has a 3065 corresponding API for third-party developers, the device implementation MUST 3066 implement that API as described in the Android SDK documentation and the 3067 Android Open Source documentation on sensors [<a href="http://source.android.com/devices/sensors/">Resources, 73</a>]. For example, device implementations:</p> 3068 3069 <ul> 3070 <li>MUST accurately report the presence or absence of sensors per the 3071 android.content.pm.PackageManager class [<a href="http://developer.android.com/reference/android/content/pm/PackageManager.html">Resources, 53]</a>.</li> 3072 <li>MUST return an accurate list of supported sensors via the 3073 SensorManager.getSensorList() and similar methods.</li> 3074 <li>MUST behave reasonably for all other sensor APIs (for example, by returning 3075 true or false as appropriate when applications attempt to register listeners, 3076 not calling sensor listeners when the corresponding sensors are not present; 3077 etc.).</li> 3078 <li>MUST report all sensor measurements using the relevant International System of 3079 Units (metric) values for each sensor type as defined in the Android SDK 3080 documentation [<a href="http://developer.android.com/reference/android/hardware/SensorEvent.html">Resources, 74</a>].</li> 3081 <li>SHOULD report the event time in nanoseconds as defined in the Android SDK 3082 documentation, representing the time the event happened and synchronized with 3083 the SystemClock.elapsedRealtimeNano() clock. Existing and new Android devices 3084 are <strong>very strongly encouraged</strong> to meet these requirement so they will be able to upgrade to the future 3085 platform releases where this might become a REQUIRED component. The 3086 synchronization error SHOULD be below 100 milliseconds [<a href="http://developer.android.com/reference/android/hardware/SensorEvent.html#timestamp">Resources, 75</a>].</li> 3087 </ul> 3088 3089 <p>The list above is not comprehensive; the documented behavior of the Android SDK 3090 and the Android Open Source Documentations on Sensors [<a href="http://source.android.com/devices/sensors/">Resources, 73</a>] is to be considered authoritative.</p> 3091 3092 <p>Some sensor types are composite, meaning they can be derived from data provided 3093 by one or more other sensors. (Examples include the orientation sensor, and the 3094 linear acceleration sensor.) Device implementations SHOULD implement these 3095 sensor types, when they include the prerequisite physical sensors as described 3096 in [<a href="https://source.android.com/devices/sensors/sensor-types.html">Resources, 76</a>]. 3097 If a device implementation includes a composite sensor it MUST implement the 3098 sensor as described in the Android Open Source documentation on composite 3099 sensors [<a href="https://source.android.com/devices/sensors/sensor-types.html#composite_sensor_type_summary">Resources, 76</a>].</p> 3100 3101 <p>Some Android sensors support a “continuous” trigger mode, which returns data 3102 continuously [<a href="https://source.android.com/devices/sensors/report-modes.html#continuous">Resources, 77</a>]. For any API indicated by the Android SDK documentation to be a continuous 3103 sensor, device implementations MUST continuously provide periodic data samples 3104 that SHOULD have a jitter below 3%, where jitter is defined as the standard 3105 deviation of the difference of the reported timestamp values between 3106 consecutive events.</p> 3107 3108 <p>Note that the device implementations MUST ensure that the sensor event stream 3109 MUST NOT prevent the device CPU from entering a suspend state or waking up from 3110 a suspend state.</p> 3111 3112 <p>Finally, when several sensors are activated, the power consumption SHOULD NOT 3113 exceed the sum of the individual sensor’s reported power consumption.</p> 3114 3115 <h3 id="7_3_1_accelerometer">7.3.1. Accelerometer</h3> 3116 3117 3118 <p>Device implementations SHOULD include a 3-axis accelerometer. Android Handheld 3119 devices and Android Watch devices are strongly encouraged to include this 3120 sensor. If a device implementation does include a 3-axis accelerometer, it:</p> 3121 3122 <ul> 3123 <li>MUST implement and report TYPE_ACCELEROMETER sensor [<a href="http://developer.android.com/reference/android/hardware/Sensor.html#TYPE_ACCELEROMETER">Resources, 78</a>].</li> 3124 <li>MUST be able to report events up to a frequency of at least 50 Hz for 3125 Android Watch devices as such devices have a stricter power constraint and 3126 100 Hz for all other device types.</li> 3127 <li>SHOULD report events up to at least 200 Hz.</li> 3128 <li>MUST comply with the Android sensor coordinate system as detailed in the 3129 Android APIs [<a href="http://developer.android.com/reference/android/hardware/SensorEvent.html">Resources, 74</a>].</li> 3130 <li>MUST be capable of measuring from freefall up to four times the gravity (4g) or 3131 more on any axis.</li> 3132 <li>MUST have a resolution of at least 8-bits and SHOULD have a resolution of at 3133 least 16-bits.</li> 3134 <li>SHOULD be calibrated while in use if the characteristics changes over the life 3135 cycle and compensated, and preserve the compensation parameters between device 3136 reboots.</li> 3137 <li>SHOULD be temperature compensated.</li> 3138 <li>MUST have a standard deviation no greater than 0.05 m/s^, where the standard 3139 deviation should be calculated on a per axis basis on samples collected over a 3140 period of at least 3 seconds at the fastest sampling rate.</li> 3141 <li>SHOULD implement the TYPE_SIGNIFICANT_MOTION, TYPE_TILT_DETECTOR, 3142 TYPE_STEP_DETECTOR, TYPE_STEP_COUNTER composite sensors as described in the 3143 Android SDK document. Existing and new Android devices are <strong>very strongly encouraged</strong> to implement the TYPE_SIGNIFICANT_MOTION composite sensor. If any of these 3144 sensors are implemented, the sum of their power consumption MUST always be less 3145 than 4 mW and SHOULD each be below 2 mW and 0.5 mW for when the device is in a 3146 dynamic or static condition.</li> 3147 <li>If a gyroscope sensor is included, MUST implement the TYPE_GRAVITY and 3148 TYPE_LINEAR_ACCELERATION composite sensors and SHOULD implement the 3149 TYPE_GAME_ROTATION_VECTOR composite sensor. Existing and new Android devices 3150 are strongly encouraged to implement the TYPE_GAME_ROTATION_VECTOR sensor.</li> 3151 <li>SHOULD implement a TYPE_ROTATION_VECTOR composite sensor, if a gyroscope sensor 3152 and a magnetometer sensor is also included.</li> 3153 </ul> 3154 3155 <h3 id="7_3_2_magnetometer">7.3.2. Magnetometer</h3> 3156 3157 3158 <p>Device implementations SHOULD include a 3-axis magnetometer (compass). If a 3159 device does include a 3-axis magnetometer, it:</p> 3160 3161 <ul> 3162 <li>MUST implement the TYPE_MAGNETIC_FIELD sensor and SHOULD also implement 3163 TYPE_MAGNETIC_FIELD_UNCALIBRATED sensor. Existing and new Android devices are 3164 strongly encouraged to implement the TYPE_MAGNETIC_FIELD_UNCALIBRATED sensor.</li> 3165 <li>MUST be able to report events up to a frequency of at least 10 Hz and SHOULD 3166 report events up to at least 50 Hz.</li> 3167 <li>MUST comply with the Android sensor coordinate system as detailed in the 3168 Android APIs [<a href="http://developer.android.com/reference/android/hardware/SensorEvent.html">Resources, 74</a>].</li> 3169 <li>MUST be capable of measuring between -900 µT and +900 µT on each axis before 3170 saturating.</li> 3171 <li>MUST have a hard iron offset value less than 700 µT and SHOULD have a value 3172 below 200 µT, by placing the magnetometer far from dynamic (current-induced) 3173 and static (magnet-induced) magnetic fields.</li> 3174 <li>MUST have a resolution equal or denser than 0.6 µT and SHOULD have a resolution 3175 equal or denser than 0.2 µ.</li> 3176 <li>SHOULD be temperature compensated.</li> 3177 <li>MUST support online calibration and compensation of the hard iron bias, and 3178 preserve the compensation parameters between device reboots.</li> 3179 <li>MUST have the soft iron compensation applied—the calibration can be done either 3180 while in use or during the production of the device.</li> 3181 <li>SHOULD have a standard deviation, calculated on a per axis basis on samples 3182 collected over a period of at least 3 seconds at the fastest sampling rate, no 3183 greater than 0.5 µT.</li> 3184 <li>SHOULD implement a TYPE_ROTATION_VECTOR composite sensor, if an accelerometer 3185 sensor and a gyroscope sensor is also included.</li> 3186 <li>MAY implement the TYPE_GEOMAGNETIC_ROTATION_VECTOR sensor if an accelerometer 3187 sensor is also implemented. However if implemented, it MUST consume less than 3188 10 mW and SHOULD consume less than 3 mW when the sensor is registered for batch 3189 mode at 10 Hz.</li> 3190 </ul> 3191 3192 <h3 id="7_3_3_gps">7.3.3. GPS</h3> 3193 3194 3195 <p>Device implementations SHOULD include a GPS receiver. If a device 3196 implementation does include a GPS receiver, it SHOULD include some form of“assisted GPS” technique to minimize GPS lock-on time.</p> 3197 3198 <h3 id="7_3_4_gyroscope">7.3.4. Gyroscope</h3> 3199 3200 3201 <p>Device implementations SHOULD include a gyroscope (angular change sensor). 3202 Devices SHOULD NOT include a gyroscope sensor unless a 3-axis accelerometer is 3203 also included. If a device implementation includes a gyroscope, it:</p> 3204 3205 <ul> 3206 <li>MUST implement the TYPE_GYROSCOPE sensor and SHOULD also implement 3207 TYPE_GYROSCOPE_UNCALIBRATED sensor. Existing and new Android devices are 3208 strongly encouraged to implement the SENSOR_TYPE_GYROSCOPE_UNCALIBRATED sensor.</li> 3209 <li>MUST be capable of measuring orientation changes up to 1,000 degrees per second.</li> 3210 <li>MUST be able to report events up to a frequency of at least 50 Hz for 3211 Android Watch devices as such devices have a stricter power constraint and 3212 100 Hz for all other device types.</li> 3213 <li>SHOULD report events up to at least 200 Hz.</li> 3214 <li>MUST have a resolution of 12-bits or more and SHOULD have a resolution of 3215 16-bits or more.</li> 3216 <li>MUST be temperature compensated.</li> 3217 <li>MUST be calibrated and compensated while in use, and preserve the compensation 3218 parameters between device reboots.</li> 3219 <li>MUST have a variance no greater than 1e-7 rad^2 / s^2 per Hz (variance per Hz, 3220 or rad^2 / s). The variance is allowed to vary with the sampling rate, but must 3221 be constrained by this value. In other words, if you measure the variance of 3222 the gyro at 1 Hz sampling rate it should be no greater than 1e-7 rad^2/s^2.</li> 3223 <li>SHOULD implement a TYPE_ROTATION_VECTOR composite sensor, if an accelerometer 3224 sensor and a magnetometer sensor is also included.</li> 3225 <li>If an accelerometer sensor is included, MUST implement the TYPE_GRAVITY and 3226 TYPE_LINEAR_ACCELERATION composite sensors and SHOULD implement the 3227 TYPE_GAME_ROTATION_VECTOR composite sensor. Existing and new Android devices 3228 are strongly encouraged to implement the TYPE_GAME_ROTATION_VECTOR sensor.</li> 3229 </ul> 3230 3231 <h3 id="7_3_5_barometer">7.3.5. Barometer</h3> 3232 3233 3234 <p>Device implementations SHOULD include a barometer (ambient air pressure 3235 sensor). If a device implementation includes a barometer, it:</p> 3236 3237 <ul> 3238 <li>MUST implement and report TYPE_PRESSURE sensor.</li> 3239 <li>MUST be able to deliver events at 5 Hz or greater.</li> 3240 <li>MUST have adequate precision to enable estimating altitude.</li> 3241 <li>MUST be temperature compensated.</li> 3242 </ul> 3243 3244 <h3 id="7_3_6_thermometer">7.3.6. Thermometer</h3> 3245 3246 3247 <p>Device implementations MAY include an ambient thermometer (temperature sensor). 3248 If present, it MUST be defined as SENSOR_TYPE_AMBIENT_TEMPERATURE and it MUST 3249 measure the ambient (room) temperature in degrees Celsius.</p> 3250 3251 <p>Device implementations MAY but SHOULD NOT include a CPU temperature sensor. If 3252 present, it MUST be defined as SENSOR_TYPE_TEMPERATURE, it MUST measure the 3253 temperature of the device CPU, and it MUST NOT measure any other temperature. 3254 Note the SENSOR_TYPE_TEMPERATURE sensor type was deprecated in Android 4.0.</p> 3255 3256 <h3 id="7_3_7_photometer">7.3.7. Photometer</h3> 3257 3258 3259 <p>Device implementations MAY include a photometer (ambient light sensor).</p> 3260 3261 <h3 id="7_3_8_proximity_sensor">7.3.8. Proximity Sensor</h3> 3262 3263 3264 <p>Device implementations MAY include a proximity sensor. Devices that can make a 3265 voice call and indicate any value other than PHONE_TYPE_NONE in getPhoneType 3266 SHOULD include a proximity sensor. If a device implementation does include a 3267 proximity sensor, it:</p> 3268 3269 <ul> 3270 <li>MUST measure the proximity of an object in the same direction as the screen. 3271 That is, the proximity sensor MUST be oriented to detect objects close to the 3272 screen, as the primary intent of this sensor type is to detect a phone in use 3273 by the user. If a device implementation includes a proximity sensor with any 3274 other orientation, it MUST NOT be accessible through this API.</li> 3275 <li>MUST have 1-bit of accuracy or more.</li> 3276 </ul> 3277 3278 <h2 id="7_4_data_connectivity">7.4. Data Connectivity</h2> 3279 3280 3281 <h3 id="7_4_1_telephony">7.4.1. Telephony</h3> 3282 3283 3284 <p>“Telephony” as used by the Android APIs and this document refers specifically 3285 to hardware related to placing voice calls and sending SMS messages via a GSM 3286 or CDMA network. While these voice calls may or may not be packet-switched, 3287 they are for the purposes of Android considered independent of any data 3288 connectivity that may be implemented using the same network. In other words, 3289 the Android “telephony” functionality and APIs refer specifically to voice 3290 calls and SMS. For instance, device implementations that cannot place calls or 3291 send/receive SMS messages MUST NOT report the android.hardware.telephony 3292 feature or any subfeatures, regardless of whether they use a cellular network 3293 for data connectivity.</p> 3294 3295 <p>Android MAY be used on devices that do not include telephony hardware. That is, 3296 Android is compatible with devices that are not phones. However, if a device 3297 implementation does include GSM or CDMA telephony, it MUST implement full 3298 support for the API for that technology. Device implementations that do not 3299 include telephony hardware MUST implement the full APIs as no-ops.</p> 3300 3301 <h3 id="7_4_2_ieee_802_11_wi-fi">7.4.2. IEEE 802.11 (Wi-Fi)</h3> 3302 3303 <div class="note"> 3304 <p>Android Television device implementations MUST include Wi-Fi support.</p> 3305 </div> 3306 3307 3308 <p>Android Television device implementations MUST include support for one or more 3309 forms of 802.11 (b/g/a/n, etc.) and other types of Android device 3310 implementation SHOULD include support for one or more forms of 802.11. If a 3311 device implementation does include support for 802.11 and exposes the 3312 functionality to a third-party application, it MUST implement the corresponding 3313 Android API and:</p> 3314 3315 <ul> 3316 <li>MUST report the hardware feature flag android.hardware.wifi.</li> 3317 <li>MUST implement the multicast API as described in the SDK documentation [<a href="http://developer.android.com/reference/android/net/wifi/WifiManager.MulticastLock.html">Resources, 79</a>].</li> 3318 <li>MUST support multicast DNS (mDNS) and MUST NOT filter mDNS packets 3319 (224.0.0.251) at any time of operation including when the screen is not in an 3320 active state.</li> 3321 </ul> 3322 3323 <h4 id="7_4_2_1_wi-fi_direct">7.4.2.1. Wi-Fi Direct</h4> 3324 3325 3326 <p>Device implementations SHOULD include support for Wi-Fi Direct (Wi-Fi 3327 peer-to-peer). If a device implementation does include support for Wi-Fi 3328 Direct, it MUST implement the corresponding Android API as described in the SDK 3329 documentation [<a href="http://developer.android.com/reference/android/net/wifi/p2p/WifiP2pManager.html">Resources, 80</a>]. If a device implementation includes support for Wi-Fi Direct, then it:</p> 3330 3331 <ul> 3332 <li>MUST report the hardware feature android.hardware.wifi.direct.</li> 3333 <li>MUST support regular Wi-Fi operation.</li> 3334 <li>SHOULD support concurrent Wi-Fi and Wi-Fi Direct operation.</li> 3335 </ul> 3336 3337 <h4 id="7_4_2_2_wi-fi_tunneled_direct_link_setup">7.4.2.2. Wi-Fi Tunneled Direct Link Setup</h4> 3338 3339 <div class="note"> 3340 <p>Android Television device implementations MUST include support for Wi-Fi 3341 Tunneled Direct Link Setup (TDLS).</p> 3342 </div> 3343 3344 3345 <p>Android Television device implementations MUST include support for Wi-Fi 3346 Tunneled Direct Link Setup (TDLS) and other types of Android device 3347 implementations SHOULD include support for Wi-Fi TDLS as described in the 3348 Android SDK Documentation [<a href="http://developer.android.com/reference/android/net/wifi/WifiManager.html">Resources, 81</a>]. If a device implementation does include support for TDLS and TDLS is enabled 3349 by the WiFiManager API, the device:</p> 3350 3351 <ul> 3352 <li>SHOULD use TDLS only when it is possible AND beneficial.</li> 3353 <li>SHOULD have some heuristic and NOT use TDLS when its performance might be worse 3354 than going through the Wi-Fi access point.</li> 3355 </ul> 3356 3357 <h3 id="7_4_3_bluetooth">7.4.3. Bluetooth</h3> 3358 3359 <div class="note"> 3360 <p>Android Watch and Automotive implementations MUST support Bluetooth. Android 3361 Television implementations MUST support Bluetooth and Bluetooth LE.</p> 3362 </div> 3363 3364 3365 <p>Android includes support for Bluetooth and Bluetooth Low Energy [<a href="http://developer.android.com/reference/android/bluetooth/package-summary.html">Resources, 82</a>]. Device implementations that include support for Bluetooth and Bluetooth Low 3366 Energy MUST declare the relevant platform features (android.hardware.bluetooth 3367 and android.hardware.bluetooth_le respectively) and implement the platform 3368 APIs. Device implementations SHOULD implement relevant Bluetooth profiles such 3369 as A2DP, AVCP, OBEX, etc. as appropriate for the device. Android Television 3370 device implementations MUST support Bluetooth and Bluetooth LE. </p> 3371 3372 <p>Device implementations including support for Bluetooth Low Energy:</p> 3373 3374 <ul> 3375 <li>MUST declare the hardware feature android.hardware.bluetooth_le.</li> 3376 <li>MUST enable the GATT (generic attribute profile) based Bluetooth APIs as 3377 described in the SDK documentation and [<a href="http://developer.android.com/reference/android/bluetooth/package-summary.html">Resources, 82</a>].</li> 3378 <li>SHOULD support offloading of the filtering logic to the bluetooth chipset when 3379 implementing the ScanFilter API [<a href="https://developer.android.com/reference/android/bluetooth/le/ScanFilter.html">Resources, 83</a>], and MUST report the correct value of where the filtering logic is implemented whenever queried via the 3380 android.bluetooth.BluetoothAdapter.isOffloadedFilteringSupported() method.</li> 3381 <li>SHOULD support offloading of the batched scanning to the bluetooth chipset, but 3382 if not supported, MUST report ‘false’ whenever queried via the 3383 android.bluetooth.BluetoothAdapater.isOffloadedScanBatchingSupported() method.</li> 3384 <li>SHOULD support multi advertisement with at least 4 slots, but if not supported, 3385 MUST report ‘false’ whenever queried via the 3386 android.bluetooth.BluetoothAdapter.isMultipleAdvertisementSupported() method.</li> 3387 </ul> 3388 3389 <h3 id="7_4_4_near-field_communications">7.4.4. Near-Field Communications</h3> 3390 3391 3392 <p>Device implementations SHOULD include a transceiver and related hardware for 3393 Near-Field Communications (NFC). If a device implementation does include NFC 3394 hardware and plans to make it available to third-party apps, then it:</p> 3395 3396 <ul> 3397 <li>MUST report the android.hardware.nfc feature from the 3398 android.content.pm.PackageManager.hasSystemFeature() method [<a href="http://developer.android.com/reference/android/content/pm/PackageManager.html">Resources, 53</a>].</li> 3399 <li>MUST be capable of reading and writing NDEF messages via the following NFC 3400 standards: 3401 <ul> 3402 <li>MUST be capable of acting as an NFC Forum reader/writer (as defined by the NFC 3403 Forum technical specification NFCForum-TS-DigitalProtocol-1.0) via the 3404 following NFC standards: 3405 <ul> 3406 <li>NfcA (ISO14443-3A)</li> 3407 <li>NfcB (ISO14443-3B)</li> 3408 <li>NfcF (JIS 6319-4)</li> 3409 <li>IsoDep (ISO 14443-4)</li> 3410 <li>NFC Forum Tag Types 1, 2, 3, 4 (defined by the NFC Forum)</li> 3411 </ul> 3412 <li>SHOULD be capable of reading and writing NDEF messages via the following NFC 3413 standards. Note that while the NFC standards below are stated as SHOULD, the 3414 Compatibility Definition for a future version is planned to change these to 3415 MUST. These standards are optional in this version but will be required in 3416 future versions. Existing and new devices that run this version of Android are <strong>very strongly encouraged</strong> to meet these requirements now so they will be able to upgrade to the future platform releases.</li> 3417 <ul> 3418 <li>NfcV (ISO 15693)</li> 3419 </ul></li> 3420 <li>MUST be capable of transmitting and receiving data via the following 3421 peer-to-peer standards and protocols: 3422 <ul> 3423 <li>ISO 18092</li> 3424 <li>LLCP 1.0 (defined by the NFC Forum)</li> 3425 <li>SDP 1.0 (defined by the NFC Forum)</li> 3426 <li>NDEF Push Protocol [<a href="http://static.googleusercontent.com/media/source.android.com/en/us/compatibility/ndef-push-protocol.pdf">Resources, 84</a>]</li> 3427 <li>SNEP 1.0 (defined by the NFC Forum)</li> 3428 </ul></li> 3429 <li>MUST include support for Android Beam [<a href="http://developer.android.com/guide/topics/connectivity/nfc/nfc.html">Resources, 85</a>]: 3430 <ul> 3431 <li>MUST implement the SNEP default server. Valid NDEF messages received by the 3432 default SNEP server MUST be dispatched to applications using the 3433 android.nfc.ACTION_NDEF_DISCOVERED intent. Disabling Android Beam in settings 3434 MUST NOT disable dispatch of incoming NDEF message.</li> 3435 <li>MUST honor the android.settings.NFCSHARING_SETTINGS intent to show NFC sharing 3436 settings [<a href="http://developer.android.com/reference/android/provider/Settings.html#ACTION_NFCSHARING_SETTINGS">Resources, 86</a>].</li> 3437 <li>MUST implement the NPP server. Messages received by the NPP server MUST be 3438 processed the same way as the SNEP default server.</li> 3439 <li>MUST implement a SNEP client and attempt to send outbound P2P NDEF to the 3440 default SNEP server when Android Beam is enabled. If no default SNEP server is 3441 found then the client MUST attempt to send to an NPP server.</li> 3442 <li>MUST allow foreground activities to set the outbound P2P NDEF message using 3443 android.nfc.NfcAdapter.setNdefPushMessage, and 3444 android.nfc.NfcAdapter.setNdefPushMessageCallback, and 3445 android.nfc.NfcAdapter.enableForegroundNdefPush.</li> 3446 <li>SHOULD use a gesture or on-screen confirmation, such as 'Touch to Beam', before 3447 sending outbound P2P NDEF messages.</li> 3448 <li>SHOULD enable Android Beam by default and MUST be able to send and receive 3449 using Android Beam, even when another proprietary NFC P2p mode is turned on.</li> 3450 <li>MUST support NFC Connection handover to Bluetooth when the device supports 3451 Bluetooth Object Push Profile. Device implementations MUST support connection 3452 handover to Bluetooth when using android.nfc.NfcAdapter.setBeamPushUris, by 3453 implementing the “Connection Handover version 1.2” [<a href="http://members.nfc-forum.org/specs/spec_list/#conn_handover">Resources, 87</a>] and “Bluetooth Secure Simple Pairing Using NFC version 1.0” [<a href="http://members.nfc-forum.org/apps/group_public/download.php/18688/NFCForum-AD-BTSSP_1_1.pdf">Resources, 88</a>] specs from the NFC Forum. Such an implementation MUST implement the handover 3454 LLCP service with service name “urn:nfc:sn:handover” for exchanging the 3455 handover request/select records over NFC, and it MUST use the Bluetooth Object 3456 Push Profile for the actual Bluetooth data transfer. For legacy reasons (to 3457 remain compatible with Android 4.1 devices), the implementation SHOULD still 3458 accept SNEP GET requests for exchanging the handover request/select records 3459 over NFC. However an implementation itself SHOULD NOT send SNEP GET requests 3460 for performing connection handover.</li> 3461 </ul></li> 3462 <li>MUST poll for all supported technologies while in NFC discovery mode.</li> 3463 <li>SHOULD be in NFC discovery mode while the device is awake with the screen 3464 active and the lock-screen unlocked.</li> 3465 </ul> 3466 </ul> 3467 3468 <p>(Note that publicly available links are not available for the JIS, ISO, and NFC 3469 Forum specifications cited above.)</p> 3470 3471 <p>Android includes support for NFC Host Card Emulation (HCE) mode. If a 3472 device implementation does include an NFC controller chipset capable of HCE and 3473 Application ID (AID) routing, then it:</p> 3474 3475 <ul> 3476 <li>MUST report the android.hardware.nfc.hce feature constant.</li> 3477 <li>MUST support NFC HCE APIs as defined in the Android SDK [<a href="http://developer.android.com/guide/topics/connectivity/nfc/hce.html">Resources, 10</a>].</li> 3478 </ul> 3479 3480 <p>Additionally, device implementations MAY include reader/writer support for the 3481 following MIFARE technologies.</p> 3482 3483 <ul> 3484 <li>MIFARE Classic</li> 3485 <li>MIFARE Ultralight</li> 3486 <li>NDEF on MIFARE Classic</li> 3487 </ul> 3488 3489 <p>Note that Android includes APIs for these MIFARE types. If a device 3490 implementation supports MIFARE in the reader/writer role, it:</p> 3491 3492 <ul> 3493 <li>MUST implement the corresponding Android APIs as documented by the Android SDK.</li> 3494 <li>MUST report the feature com.nxp.mifare from the 3495 android.content.pm.PackageManager.hasSystemFeature() meth<a href="http://developer.android.com/reference/android/content/pm/PackageManager.html">od [Resources, 53]</a>. Note that this is not a standard Android feature and as such does not appear 3496 as a constant on the PackageManager class.</li> 3497 <li>MUST NOT implement the corresponding Android APIs nor report the com.nxp.mifare 3498 feature unless it also implements general NFC support as described in this 3499 section.</li> 3500 </ul> 3501 3502 <p>If a device implementation does not include NFC hardware, it MUST NOT declare 3503 the android.hardware.nfc feature from the 3504 android.content.pm.PackageManager.hasSystemFeature() method [<a href="http://developer.android.com/reference/android/content/pm/PackageManager.html">Resources, 53]</a>, and MUST implement the Android NFC API as a no-op.</p> 3505 3506 <p>As the classes android.nfc.NdefMessage and android.nfc.NdefRecord represent a 3507 protocol-independent data representation format, device implementations MUST 3508 implement these APIs even if they do not include support for NFC or declare the 3509 android.hardware.nfc feature.</p> 3510 3511 <h3 id="7_4_5_minimum_network_capability">7.4.5. Minimum Network Capability</h3> 3512 3513 3514 <p>Device implementations MUST include support for one or more forms of data 3515 networking. Specifically, device implementations MUST include support for at 3516 least one data standard capable of 200Kbit/sec or greater. Examples of 3517 technologies that satisfy this requirement include EDGE, HSPA, EV-DO, 802.11g, 3518 Ethernet, Bluetooth PAN, etc.</p> 3519 3520 <p>Device implementations where a physical networking standard (such as Ethernet) 3521 is the primary data connection SHOULD also include support for at least one 3522 common wireless data standard, such as 802.11 (Wi-Fi).</p> 3523 3524 <p>Devices MAY implement more than one form of data connectivity.</p> 3525 3526 <h3 id="7_4_6_sync_settings">7.4.6. Sync Settings</h3> 3527 3528 3529 <p>Device implementations MUST have the master auto-sync setting on by default so 3530 that the method getMasterSyncAutomatically() returns “true” [<a href="http://developer.android.com/reference/android/content/ContentResolver.html">Resources, 89</a>].</p> 3531 3532 <h2 id="7_5_cameras">7.5. Cameras</h2> 3533 3534 3535 <p>Device implementations SHOULD include a rear-facing camera and MAY include a 3536 front-facing camera. A rear-facing camera is a camera located on the side of 3537 the device opposite the display; that is, it images scenes on the far side of 3538 the device, like a traditional camera. A front-facing camera is a camera 3539 located on the same side of the device as the display; that is, a camera 3540 typically used to image the user, such as for video conferencing and similar 3541 applications.</p> 3542 3543 <p>If a device implementation includes at least one camera, it SHOULD be possible 3544 for an application to simultaneously allocate 3 bitmaps equal to the size of 3545 the images produced by the largest-resolution camera sensor on the device.</p> 3546 3547 <h3 id="7_5_1_rear-facing_camera">7.5.1. Rear-Facing Camera</h3> 3548 3549 3550 <p>Device implementations SHOULD include a rear-facing camera. If a device 3551 implementation includes at least one rear-facing camera, it:</p> 3552 3553 <ul> 3554 <li>MUST report the feature flag android.hardware.camera and 3555 android.hardware.camera.any.</li> 3556 <li>MUST have a resolution of at least 2 megapixels.</li> 3557 <li>SHOULD have either hardware auto-focus or software auto-focus implemented in 3558 the camera driver (transparent to application software).</li> 3559 <li>MAY have fixed-focus or EDOF (extended depth of field) hardware.</li> 3560 <li>MAY include a flash. If the Camera includes a flash, the flash lamp MUST NOT be 3561 lit while an android.hardware.Camera.PreviewCallback instance has been 3562 registered on a Camera preview surface, unless the application has explicitly 3563 enabled the flash by enabling the FLASH_MODE_AUTO or FLASH_MODE_ON attributes 3564 of a Camera.Parameters object. Note that this constraint does not apply to the 3565 device’s built-in system camera application, but only to third-party 3566 applications using Camera.PreviewCallback.</li> 3567 </ul> 3568 3569 <h3 id="7_5_2_front-facing_camera">7.5.2. Front-Facing Camera</h3> 3570 3571 3572 <p>Device implementations MAY include a front-facing camera. If a device 3573 implementation includes at least one front-facing camera, it:</p> 3574 3575 <ul> 3576 <li>MUST report the feature flag android.hardware.camera.any and 3577 android.hardware.camera.front.</li> 3578 <li>MUST have a resolution of at least VGA (640x480 pixels).</li> 3579 <li>MUST NOT use a front-facing camera as the default for the Camera API. The 3580 camera API in Android has specific support for front-facing cameras and device 3581 implementations MUST NOT configure the API to to treat a front-facing camera as 3582 the default rear-facing camera, even if it is the only camera on the device.</li> 3583 <li>MAY include features (such as auto-focus, flash, etc.) available to rear-facing 3584 cameras as described in <a href="#7_5_1_rear-facing_camera">section 7.5.1</a>.</li> 3585 <li>MUST horizontally reflect (i.e. mirror) the stream displayed by an app in a 3586 CameraPreview, as follows: 3587 <ul> 3588 <li>If the device implementation is capable of being rotated by user (such as 3589 automatically via an accelerometer or manually via user input), the camera 3590 preview MUST be mirrored horizontally relative to the device’s current 3591 orientation.</li> 3592 <li>If the current application has explicitly requested that the Camera display be 3593 rotated via a call to the android.hardware.Camera.setDisplayOrientation()[<a href="http://developer.android.com/reference/android/hardware/Camera.html#setDisplayOrientation(int)">Resources, 90</a>] method, the camera preview MUST be mirrored horizontally relative to the 3594 orientation specified by the application.</li> 3595 <li>Otherwise, the preview MUST be mirrored along the device’s default horizontal 3596 axis.</li> 3597 </ul></li> 3598 <li>MUST mirror the image displayed by the postview in the same manner as the 3599 camera preview image stream. If the device implementation does not support 3600 postview, this requirement obviously does not apply.</li> 3601 <li>MUST NOT mirror the final captured still image or video streams returned to 3602 application callbacks or committed to media storage.</li> 3603 </ul> 3604 3605 <h3 id="7_5_3_external_camera">7.5.3. External Camera</h3> 3606 3607 3608 <p>Device implementations with USB host mode MAY include support for an external 3609 camera that connects to the USB port. If a device includes support for an 3610 external camera, it:</p> 3611 3612 <ul> 3613 <li>MUST declare the platform feature android.hardware.camera.external and 3614 android.hardware camera.any.</li> 3615 <li>MUST support USB Video Class (UVC 1.0 or higher).</li> 3616 <li>MAY support multiple cameras.</li> 3617 </ul> 3618 3619 <p>Video compression (such as MJPEG) support is RECOMMENDED to enable transfer of 3620 high-quality unencoded streams (i.e. raw or independently compressed picture 3621 streams). Camera-based video encoding MAY be supported. If so, a simultaneous 3622 unencoded/ MJPEG stream (QVGA or greater resolution) MUST be accessible to the 3623 device implementation.</p> 3624 3625 <h3 id="7_5_4_camera_api_behavior">7.5.4. Camera API Behavior</h3> 3626 3627 3628 <p>Android includes two API packages to access the camera, the newer 3629 android.hardware.camera2 API expose lower-level camera control to the app, 3630 including efficient zero-copy burst/streaming flows and per-frame controls of 3631 exposure, gain, white balance gains, color conversion, denoising, sharpening, 3632 and more.</p> 3633 3634 <p>The older API package, android.hardware.Camera, is marked as deprecated in 3635 Android 5.0 but as it should still be available for apps to use Android device 3636 implementations MUST ensure the continued support of the API as described in 3637 this section and in the Android SDK.</p> 3638 3639 <p>Device implementations MUST implement the following behaviors for the 3640 camera-related APIs, for all available cameras:</p> 3641 3642 <ul> 3643 <li>If an application has never called 3644 android.hardware.Camera.Parameters.setPreviewFormat(int), then the device MUST 3645 use android.hardware.PixelFormat.YCbCr_420_SP for preview data provided to 3646 application callbacks.</li> 3647 <li>If an application registers an android.hardware.Camera.PreviewCallback instance 3648 and the system calls the onPreviewFrame() method when the preview format is 3649 YCbCr_420_SP, the data in the byte[] passed into onPreviewFrame() must further 3650 be in the NV21 encoding format. That is, NV21 MUST be the default.</li> 3651 <li>For android.hardware.Camera, device implementations MUST support the YV12 3652 format (as denoted by the android.graphics.ImageFormat.YV12 constant) for 3653 camera previews for both front- and rear-facing cameras. (The hardware video 3654 encoder and camera may use any native pixel format, but the device 3655 implementation MUST support conversion to YV12.)</li> 3656 <li>For android.hardware.camera2, device implementations must support the 3657 android.hardware.ImageFormat.YUV_420_888 and android.hardware.ImageFormat.JPEG 3658 formats as outputs through the android.media.ImageReader API.</li> 3659 </ul> 3660 3661 <p>Device implementations MUST still implement the full Camera API included in the 3662 Android SDK documentation [<a href="http://developer.android.com/reference/android/hardware/Camera.html">Resources, 91</a>], regardless of whether the device includes hardware autofocus or other 3663 capabilities. For instance, cameras that lack autofocus MUST still call any 3664 registered android.hardware.Camera.AutoFocusCallback instances (even though 3665 this has no relevance to a non-autofocus camera.) Note that this does apply to 3666 front-facing cameras; for instance, even though most front-facing cameras do 3667 not support autofocus, the API callbacks must still be “faked” as described.</p> 3668 3669 <p>Device implementations MUST recognize and honor each parameter name defined as 3670 a constant on the android.hardware.Camera.Parameters class, if the underlying 3671 hardware supports the feature. If the device hardware does not support a 3672 feature, the API must behave as documented. Conversely, device implementations 3673 MUST NOT honor or recognize string constants passed to the 3674 android.hardware.Camera.setParameters() method other than those documented as 3675 constants on the android.hardware.Camera.Parameters. That is, device 3676 implementations MUST support all standard Camera parameters if the hardware 3677 allows, and MUST NOT support custom Camera parameter types. For instance, 3678 device implementations that support image capture using high dynamic range 3679 (HDR) imaging techniques MUST support camera parameter Camera.SCENE_MODE_HDR [<a href="http://developer.android.com/reference/android/hardware/Camera.Parameters.html">Resources, 92</a>].</p> 3680 3681 <p>Because not all device implementations can fully support all the features of 3682 the android.hardware.camera2 API, device implementations MUST report the proper 3683 level of support with the android.info.supportedHardwareLevel property as 3684 described in the Android SDK [<a href="https://developer.android.com/reference/android/hardware/camera2/CameraCharacteristics.html#INFO_SUPPORTED_HARDWARE_LEVEL">Resources, 93]</a> and report the appropriate framework feature flags [<a href="http://source.android.com/devices/camera/versioning.html">Resources, 94]</a>. </p> 3685 3686 <p>Device implementations MUST also declare its Individual camera capabilities of 3687 android.hardware.camera2 via the android.request.availableCapabilities property 3688 and declare the appropriate feature flags [<a href="http://source.android.com/devices/camera/versioning.html">Resources, 94]</a>; a device must define the feature flag if any of its attached camera devices supports the feature.</p> 3689 3690 <p>Device implementations MUST broadcast the Camera.ACTION_NEW_PICTURE intent 3691 whenever a new picture is taken by the camera and the entry of the picture has 3692 been added to the media store.</p> 3693 3694 <p>Device implementations MUST broadcast the Camera.ACTION_NEW_VIDEO intent 3695 whenever a new video is recorded by the camera and the entry of the picture has 3696 been added to the media store.</p> 3697 3698 <h3 id="7_5_5_camera_orientation">7.5.5. Camera Orientation</h3> 3699 3700 3701 <p>Both front- and rear-facing cameras, if present, MUST be oriented so that the 3702 long dimension of the camera aligns with the screen’s long dimension. That is, 3703 when the device is held in the landscape orientation, cameras MUST capture 3704 images in the landscape orientation. This applies regardless of the device’s 3705 natural orientation; that is, it applies to landscape-primary devices as well 3706 as portrait-primary devices.</p> 3707 3708 <h2 id="7_6_memory_and_storage">7.6. Memory and Storage</h2> 3709 3710 3711 <h3 id="7_6_1_minimum_memory_and_storage">7.6.1. Minimum Memory and Storage</h3> 3712 3713 <div class="note"> 3714 <p>Android Television devices MUST have at least 5GB of non-volatile storage 3715 available for application private data.</p> 3716 </div> 3717 3718 3719 <p>The memory available to the kernel and userspace on device implementations MUST 3720 be at least equal or larger than the minimum values specified by the following 3721 table. (See <a href="#7_1_1_screen_configuration">section 7.1.1</a> for screen size and density definitions.)</p> 3722 <table> 3723 <tr> 3724 <th>Density and screen size</th> 3725 <th>32-bit device</th> 3726 <th>64-bit device</th> 3727 </tr> 3728 <tr> 3729 <td>Android Watch devices (due to smaller screens)</td> 3730 <td>416MB</td> 3731 <td>Not applicable</td> 3732 </tr> 3733 <tr> 3734 <td><ul> 3735 <li class="table_list">280dpi or lower on small/normal screens</li> 3736 <li class="table_list">mdpi or lower on large screens</li> 3737 <li class="table_list">ldpi or lower on extra large screens</li> 3738 </ul></td> 3739 <td>424MB</td> 3740 <td>704MB</td> 3741 </tr> 3742 <tr> 3743 <td><ul> 3744 <li class="table_list">xhdpi or higher on small/normal screens</li> 3745 <li class="table_list">hdpi or higher on large screens</li> 3746 <li class="table_list">mdpi or higher on extra large screens</li></ul></td> 3747 <td>512MB</td> 3748 <td>832MB</td> 3749 </tr> 3750 <tr> 3751 <td><ul> 3752 <li class="table_list">400dpi or higher on small/normal screens</li> 3753 <li class="table_list">xhdpi or higher on large screens</li> 3754 <li class="table_list">tvdpi or higher on extra large screens</li></ul></td> 3755 <td>896MB</td> 3756 <td>1280MB</td> 3757 </tr> 3758 <tr> 3759 <td><ul> 3760 <li class="table_list">560dpi or higher on small/normal screens</li> 3761 <li class="table_list">400dpi or higher on large screens</li> 3762 <li class="table_list">xhdpi or higher on extra large screens</li></ul></td> 3763 <td>1344MB</td> 3764 <td>1824MB</td> 3765 </tr> 3766 </table> 3767 3768 3769 <p>The minimum memory values MUST be in addition to any memory space already 3770 dedicated to hardware components such as radio, video, and so on that is not 3771 under the kernel’s control.</p> 3772 3773 <p>Device implementations with less than 512MB of memory available to the kernel 3774 and userspace, unless an Android Watch, MUST return the value "true" for 3775 ActivityManager.isLowRamDevice().</p> 3776 3777 <p>Android Television devices MUST have at least 5GB and other device 3778 implementations MUST have at least 1.5GB of non-volatile storage available for 3779 application private data. That is, the /data partition MUST be at least 5GB for 3780 Android Television devices and at least 1.5GB for other device implementations. 3781 Device implementations that run Android are <strong>very strongly encouraged</strong> to have at least 3GB of non-volatile storage for application private data so 3782 they will be able to upgrade to the future platform releases.</p> 3783 3784 <p>The Android APIs include a Download Manager that applications MAY use to 3785 download data files [<a href="http://developer.android.com/reference/android/app/DownloadManager.html">Resources, 95</a>]. The device implementation of the Download Manager MUST be capable of 3786 downloading individual files of at least 100MB in size to the default “cache" 3787 location.</p> 3788 3789 <h3 id="7_6_2_application_shared_storage">7.6.2. Application Shared Storage</h3> 3790 3791 3792 <p>Device implementations MUST offer shared storage for applications also often 3793 referred as “shared external storage”. </p> 3794 3795 <p>Device implementations MUST be configured with shared storage mounted by 3796 default, “out of the box”. If the shared storage is not mounted on the Linux 3797 path /sdcard, then the device MUST include a Linux symbolic link from /sdcard 3798 to the actual mount point.</p> 3799 3800 <p>Device implementations MAY have hardware for user-accessible removable storage, 3801 such as a Secure Digital (SD) card slot. If this slot is used to satisfy the 3802 shared storage requirement, the device implementation:</p> 3803 3804 <ul> 3805 <li>MUST implement a toast or pop-up user interface warning the user when there is 3806 no SD card.</li> 3807 <li>MUST include a FAT-formatted SD card 1GB in size or larger OR show on the box 3808 and other material available at time of purchase that the SD card has to be 3809 separately purchased.</li> 3810 <li>MUST mount the SD card by default.</li> 3811 </ul> 3812 3813 <p>Alternatively, device implementations MAY allocate internal (non-removable) 3814 storage as shared storage for apps as included in the upstream Android Open 3815 Source Project; device implementations SHOULD use this configuration and 3816 software implementation. If a device implementation uses internal 3817 (non-removable) storage to satisfy the shared storage requirement, that storage 3818 MUST be 1GB in size or larger and mounted on /sdcard (or /sdcard MUST be a 3819 symbolic link to the physical location if it is mounted elsewhere).</p> 3820 3821 <p>Device implementations MUST enforce as documented the 3822 android.permission.WRITE_EXTERNAL_STORAGE permission on this shared storage. 3823 Shared storage MUST otherwise be writable by any application that obtains that 3824 permission.</p> 3825 3826 <p>Device implementations that include multiple shared storage paths (such as both 3827 an SD card slot and shared internal storage) MUST NOT allow Android 3828 applications to write to the secondary external storage, except for their 3829 package-specific directories on the secondary external storage, but SHOULD 3830 expose content from both storage paths transparently through Android’s media 3831 scanner service and android.provider.MediaStore.</p> 3832 3833 <p>Regardless of the form of shared storage used, if the device implementation 3834 has a USB port with USB peripheral mode support, it MUST provide some mechanism 3835 to access the contents of shared storage from a host computer. Device 3836 implementations MAY use USB mass storage, but SHOULD use Media Transfer Protocol 3837 to satisfy this requirement. If the device implementation supports Media 3838 Transfer Protocol, it:</p> 3839 3840 <ul> 3841 <li>SHOULD be compatible with the reference Android MTP host, Android File Transfer 3842 [<a href="http://www.android.com/filetransfer">Resources, 96</a>].</li> 3843 <li>SHOULD report a USB device class of 0x00.</li> 3844 <li>SHOULD report a USB interface name of 'MTP'.</li> 3845 </ul> 3846 3847 <h2 id="7_7_usb">7.7. USB</h2> 3848 3849 3850 <p>Device implementations SHOULD support USB peripheral mode and SHOULD support 3851 USB host mode.</p> 3852 3853 <p>If a device implementation includes a USB port supporting peripheral mode:</p> 3854 3855 <ul> 3856 <li>The port MUST be connectable to a USB host that has a standard type-A or type 3857 -C USB port.</li> 3858 <li>The port SHOULD use micro-A, micro-AB or type-C USB form factor. Existing and 3859 new Android devices are <strong>very strongly encouraged to meet these requirements</strong> so they will be able to upgrade to the future platform releases.</li> 3860 <li>The port SHOULD be centered in the middle of an edge. Device implementations 3861 SHOULD either locate the port on the bottom of the device (according to natural 3862 orientation) or enable software screen rotation for all apps (including home 3863 screen), so that the display draws correctly when the device is oriented with 3864 the port at bottom. Existing and new Android devices are <strong>very strongly encouraged to meet these requirements</strong> so they will be able to upgrade to future platform releases.</li> 3865 <li>It MUST allow a USB host connected with the Android device to access the 3866 contents of the shared storage volume using either USB mass storage or Media 3867 Transfer Protocol.</li> 3868 <li>It SHOULD implement the Android Open Accessory (AOA) API and specification as 3869 documented in the Android SDK documentation, and if it is an Android Handheld 3870 device it MUST implement the AOA API. Device implementations implementing the 3871 AOA specification: 3872 <ul> 3873 <li>MUST declare support for the hardware feature android.hardware.usb.accessory [<a href="http://developer.android.com/guide/topics/connectivity/usb/accessory.html">Resources, 97</a>].</li> 3874 <li>MUST implement the USB audio class as documented in the Android SDK 3875 documentation [<a href="http://developer.android.com/reference/android/hardware/usb/UsbConstants.html#USB_CLASS_AUDIO">Resources, 98</a>].</li> 3876 </ul></li> 3877 <li>It SHOULD implement support to draw 1.5 A current during HS chirp and traffic 3878 as specified in the USB battery charging specification [<a href="http://www.usb.org/developers/docs/devclass_docs/USB_Battery_Charging_1.2.pdf">Resources, 99</a>]. Existing and new Android devices are <strong>very strongly encouraged to meet these requirements</strong> so they will be able to upgrade to the future platform releases.</li> 3879 <li>The value of iSerialNumber in USB standard device descriptor MUST be equal to 3880 the value of android.os.Build.SERIAL.</li> 3881 </ul> 3882 3883 <p>If a device implementation includes a USB port supporting host mode, it:</p> 3884 3885 <ul> 3886 <li>SHOULD use a type-C USB port, if the device implementation supports USB 3.1.</li> 3887 <li>MAY use a non-standard port form factor, but if so MUST ship with a cable or 3888 cables adapting the port to a standard type-A or type-C USB port.</li> 3889 <li>MAY use a micro-AB USB port, but if so SHOULD ship with a cable or cables 3890 adapting the port to a standard type-A or type-C USB port.</li> 3891 <li>is <strong>very strongly RECOMMENDED</strong> to implement the USB audio class as documented in the Android SDK 3892 documentation [<a href="http://developer.android.com/reference/android/hardware/usb/UsbConstants.html#USB_CLASS_AUDIO">Resources, 98</a>].</li> 3893 <li>MUST implement the Android USB host API as documented in the Android SDK, and 3894 MUST declare support for the hardware feature android.hardware.usb.host [<a href="http://developer.android.com/guide/topics/connectivity/usb/host.html">Resources, 100</a>].</li> 3895 <li>SHOULD support the Charging Downstream Port output current range of 1.5 A ~ 5 A 3896 as specified in the USB Battery Charging Specifications [<a href="http://www.usb.org/developers/docs/devclass_docs/USB_Battery_Charging_1.2.pdf">Resources, 99</a>].</li> 3897 </ul> 3898 3899 <h2 id="7_8_audio">7.8. Audio</h2> 3900 3901 3902 <h3 id="7_8_1_microphone">7.8.1. Microphone</h3> 3903 3904 <div class="note"> 3905 <p>Android Handheld, Watch, and Automotive implementations MUST include a 3906 microphone.</p> 3907 </div> 3908 3909 3910 <p>Device implementations MAY omit a microphone. However, if a device 3911 implementation omits a microphone, it MUST NOT report the 3912 android.hardware.microphone feature constant, and MUST implement the audio 3913 recording API at least as no-ops, per <a href="#7_hardware_compatibility">section 7</a>. Conversely, device implementations that do possess a microphone:</p> 3914 3915 <ul> 3916 <li>MUST report the android.hardware.microphone feature constant 3917 <li>MUST meet the audio recording requirements in <a href="#5_4_audio_recording">section 5.4</a> 3918 <li>MUST meet the audio latency requirements in <a href="#5_6_audio_latency">section 5.6</a> 3919 </ul> 3920 3921 <h3 id="7_8_2_audio_output">7.8.2. Audio Output</h3> 3922 3923 <div class="note"> 3924 <p>Android Watch devices MAY include an audio output.</p> 3925 </div> 3926 3927 <p>Device implementations including a speaker or with an audio/multimedia output 3928 port for an audio output peripheral as a headset or an external speaker:</p> 3929 3930 <ul> 3931 <li>MUST report the android.hardware.audio.output feature constant.</li> 3932 <li>MUST meet the audio playback requirements in <a href="#5_5_audio_playback">section 5.5</a>.</li> 3933 <li>MUST meet the audio latency requirements in <a href="#5_6_audio_latency">section 5.6</a>.</li> 3934 </ul> 3935 3936 <p>Conversely, if a device implementation does not include a speaker or audio 3937 output port, it MUST NOT report the android.hardware.audio output feature, and 3938 MUST implement the Audio Output related APIs as no-ops at least. </p> 3939 3940 <p>Android Watch device implementation MAY but SHOULD NOT have audio output, but 3941 other types of Android device implementations MUST have an audio output and 3942 declare android.hardware.audio.output.</p> 3943 3944 <h4 id="7_8_2_1_analog_audio_ports">7.8.2.1. Analog Audio Ports</h4> 3945 3946 3947 <p>In order to be compatible with the headsets and other audio accessories using 3948 the 3.5mm audio plug across the Android ecosystem [<a href="http://source.android.com/accessories/headset-spec.html">Resources, 101</a>], if a device implementation includes one or more analog audio ports, at least 3949 one of the audio port(s) SHOULD be a 4 conductor 3.5mm audio jack. If a device 3950 implementation has a 4 conductor 3.5mm audio jack, it:</p> 3951 3952 <ul> 3953 <li>MUST support audio playback to stereo headphones and stereo headsets with a 3954 microphone, and SHOULD support audio recording from stereo headsets with a 3955 microphone.</li> 3956 <li>MUST support TRRS audio plugs with the CTIA pin-out order, and SHOULD support 3957 audio plugs with the OMTP pin-out order.</li> 3958 <li>MUST support the detection of microphone on the plugged in audio accessory, if 3959 the device implementation supports a microphone, and broadcast the 3960 android.intent.action.HEADSET_PLUG with the extra value microphone set as 1.</li> 3961 <li>SHOULD support the detection and mapping to the keycodes for the following 3 3962 ranges of equivalent impedance between the microphone and ground conductors on 3963 the audio plug: 3964 <ul> 3965 <li><strong>70 ohm or less</strong>: KEYCODE_HEADSETHOOK</li> 3966 <li><strong>210-290 Ohm</strong>:<strong> </strong>KEYCODE_VOLUME_UP</li> 3967 <li><strong>360-680 Ohm</strong>: KEYCODE_VOLUME_DOWN</li> 3968 </ul></li> 3969 <li>SHOULD support the detection and mapping to the keycode for the following range 3970 of equivalent impedance between the microphone and ground conductors on the 3971 audio plug: 3972 <ul> 3973 <li><strong>110-180 Ohm: </strong>KEYCODE_VOICE_ASSIST</li> 3974 </ul></li> 3975 <li>MUST trigger ACTION_HEADSET_PLUG upon a plug insert, but only after all 3976 contacts on plug are touching their relevant segments on the jack.</li> 3977 <li>MUST be capable of driving at least 150mV +/- 10% of output voltage on a 32 Ohm 3978 speaker impedance.</li> 3979 <li>MUST have a microphone bias voltage between 1.8V ~ 2.9V.</li> 3980 </ul> 3981 3982 <h1 id="8_performance_compatibility">8. Performance Compatibility</h1> 3983 3984 3985 <p>Some minimum performance criterias are critical to the user experience and 3986 impacts the baseline assumptions developers would have when developing an app. 3987 Android Watch devices SHOULD and other type of device implementations MUST meet 3988 the following criteria:</p> 3989 3990 <h2 id="8_1_user_experience_consistency">8.1. User Experience Consistency</h2> 3991 3992 3993 <p>Device implementations MUST provide a smooth user interface by ensuring a 3994 consistent frame rate and response times for applications and games. Device 3995 implementations MUST meet the following requirements: </p> 3996 3997 <ul> 3998 <li><strong>Consistent frame latency</strong>. Inconsistent frame latency or a delay to render frames MUST NOT happen more 3999 often than 5 frames in a second, and SHOULD be below 1 frames in a second.</li> 4000 <li><strong>User interface latency</strong>. Device implementations MUST ensure low latency user experience by scrolling a 4001 list of 10K list entries as defined by the Android Compatibility Test Suite 4002 (CTS) in less than 36 secs.</li> 4003 <li><strong>Task switching</strong>. When multiple applications have been launched, re-launching an already-running 4004 application after it has been launched MUST take less than 1 second.</li> 4005 </ul> 4006 4007 <h2 id="8_2_file_i_o_access_performance">8.2. File I/O Access Performance</h2> 4008 4009 4010 <p>Device implementations MUST ensure internal storage file access performance consistency for read 4011 and write operations. </p> 4012 4013 <ul> 4014 <li><strong>Sequential write</strong>. Device implementations MUST ensure a sequential write performance of at least 5MB/s 4015 for a 256MB file using 10MB write buffer.</li> 4016 <li><strong>Random write</strong>. Device implementations MUST ensure a random write performance of at least 0.5MB/s for a 4017 256MB file using 4KB write buffer.</li> 4018 <li><strong>Sequential read</strong>. Device implementations MUST ensure a sequential read performance of at least 15MB/s for 4019 a 256MB file using 10MB write buffer.</li> 4020 <li><strong>Random read</strong>. Device implementations MUST ensure a random read performance of at least 3.5MB/s for a 4021 256MB file using 4KB write buffer.</li> 4022 </ul> 4023 4024 <h1 id="9_security_model_compatibility">9. Security Model Compatibility</h1> 4025 4026 4027 <p>Device implementations MUST implement a security model consistent with the 4028 Android platform security model as defined in Security and Permissions 4029 reference document in the APIs [<a href="http://developer.android.com/guide/topics/security/permissions.html">Resources, 102</a>] in the Android developer documentation. Device implementations MUST support 4030 installation of self-signed applications without requiring any additional 4031 permissions/certificates from any third parties/authorities. Specifically, 4032 compatible devices MUST support the security mechanisms described in the follow 4033 subsections.</p> 4034 4035 <h2 id="9_1_permissions">9.1. Permissions</h2> 4036 4037 4038 <p>Device implementations MUST support the Android permissions model as defined in 4039 the Android developer documentation [<a href="http://developer.android.com/guide/topics/security/permissions.html">Resources, 102</a>]. Specifically, implementations MUST enforce each permission defined as 4040 described in the SDK documentation; no permissions may be omitted, altered, or 4041 ignored. Implementations MAY add additional permissions, provided the new 4042 permission ID strings are not in the android.* namespace.</p> 4043 4044 <h2 id="9_2_uid_and_process_isolation">9.2. UID and Process Isolation</h2> 4045 4046 4047 <p>Device implementations MUST support the Android application sandbox model, in 4048 which each application runs as a unique Unixstyle UID and in a separate 4049 process. Device implementations MUST support running multiple applications as 4050 the same Linux user ID, provided that the applications are properly signed and 4051 constructed, as defined in the Security and Permissions reference [<a href="http://developer.android.com/guide/topics/security/permissions.html">Resources, 102</a>].</p> 4052 4053 <h2 id="9_3_filesystem_permissions">9.3. Filesystem Permissions</h2> 4054 4055 4056 <p>Device implementations MUST support the Android file access permissions model 4057 as defined in the Security and Permissions reference [<a href="http://developer.android.com/guide/topics/security/permissions.html">Resources, 102</a>].</p> 4058 4059 <h2 id="9_4_alternate_execution_environments">9.4. Alternate Execution Environments</h2> 4060 4061 4062 <p>Device implementations MAY include runtime environments that execute 4063 applications using some other software or technology than the Dalvik Executable 4064 Format or native code. However, such alternate execution environments MUST NOT 4065 compromise the Android security model or the security of installed Android 4066 applications, as described in this section.</p> 4067 4068 <p>Alternate runtimes MUST themselves be Android applications, and abide by the 4069 standard Android security model, as described elsewhere in <a href="#9_security_model_compatibility">section 9</a>.</p> 4070 4071 <p>Alternate runtimes MUST NOT be granted access to resources protected by 4072 permissions not requested in the runtime’s AndroidManifest.xml file via the 4073 <uses-permission> mechanism.</p> 4074 4075 <p>Alternate runtimes MUST NOT permit applications to make use of features 4076 protected by Android permissions restricted to system applications.</p> 4077 4078 <p>Alternate runtimes MUST abide by the Android sandbox model. Specifically, 4079 alternate runtimes:</p> 4080 4081 <ul> 4082 <li>SHOULD install apps via the PackageManager into separate Android sandboxes ( 4083 Linux user IDs, etc.).</li> 4084 <li>MAY provide a single Android sandbox shared by all applications using the 4085 alternate runtime.</li> 4086 <li>and installed applications using an alternate runtime, MUST NOT reuse the 4087 sandbox of any other app installed on the device, except through the standard 4088 Android mechanisms of shared user ID and signing certificate.</li> 4089 <li>MUST NOT launch with, grant, or be granted access to the sandboxes 4090 corresponding to other Android applications.</li> 4091 <li>MUST NOT be launched with, be granted, or grant to other applications any 4092 privileges of the superuser (root), or of any other user ID.</li> 4093 </ul> 4094 4095 <p>The .apk files of alternate runtimes MAY be included in the system image of a 4096 device implementation, but MUST be signed with a key distinct from the key used 4097 to sign other applications included with the device implementation.</p> 4098 4099 <p>When installing applications, alternate runtimes MUST obtain user consent for 4100 the Android permissions used by the application. If an application needs to 4101 make use of a device resource for which there is a corresponding Android 4102 permission (such as Camera, GPS, etc.), the alternate runtime MUST inform the 4103 user that the application will be able to access that resource. If the runtime 4104 environment does not record application capabilities in this manner, the 4105 runtime environment MUST list all permissions held by the runtime itself when 4106 installing any application using that runtime.</p> 4107 4108 <h2 id="9_5_multi-user_support">9.5. Multi-User Support</h2> 4109 4110 <div class="note"> 4111 <p>This feature is optional for all device types.</p> 4112 </div> 4113 4114 4115 <p>Android includes support for multiple users and provides support for full user 4116 isolation [<a href="http://developer.android.com/reference/android/os/UserManager.html">Resources, 103]</a>. Device implementations MAY enable multiple users, but when enabled MUST meet 4117 the following requirements related to multi-user support [<a href="http://source.android.com/devices/storage/">Resources, 104</a>]:</p> 4118 4119 <ul> 4120 <li>Device implementations that do not declare the android.hardware.telephony 4121 feature flag MUST support restricted profiles, a feature that allows device 4122 owners to manage additional users and their capabilities on the device. With 4123 restricted profiles, device owners can quickly set up separate environments for 4124 additional users to work in, with the ability to manage finer-grained 4125 restrictions in the apps that are available in those environments.</li> 4126 <li>Conversely device implementations that declare the android.hardware.telephony 4127 feature flag MUST NOT support restricted profiles but MUST align with the AOSP 4128 implementation of controls to enable /disable other users from accessing the 4129 voice calls and SMS.</li> 4130 <li>Device implementations MUST, for each user, implement a security model 4131 consistent with the Android platform security model as defined in Security and 4132 Permissions reference document in the APIs [<a href="http://developer.android.com/guide/topics/security/permissions.html">Resources, 102</a>].</li> 4133 <li>Device implementations MAY support creating users and managed profiles via the 4134 android.app.admin.DevicePolicyManager APIs, and if supported, MUST declare the 4135 platform feature flag android.software.managed_users. 4136 <li>Device implementations that declare the feature flag 4137 android.software.managed_users MUST use the upstream AOSP icon badge to 4138 represent the managed applications and other badge UI elements like Recents & 4139 Notifications.</li> 4140 <li>Each user instance on an Android device MUST have separate and isolated 4141 external storage directories. Device implementations MAY store multiple users' 4142 data on the same volume or filesystem. However, the device implementation MUST 4143 ensure that applications owned by and running on behalf a given user cannot 4144 list, read, or write to data owned by any other user. Note that removable 4145 media, such as SD card slots, can allow one user to access another’s data by 4146 means of a host PC. For this reason, device implementations that use removable 4147 media for the external storage APIs MUST encrypt the contents of the SD card if 4148 multiuser is enabled using a key stored only on non-removable media accessible 4149 only to the system. As this will make the media unreadable by a host PC, device 4150 implementations will be required to switch to MTP or a similar system to 4151 provide host PCs with access to the current user’s data. Accordingly, device 4152 implementations MAY but SHOULD NOT enable multi-user if they use removable 4153 media [<a href="http://developer.android.com/reference/android/os/Environment.html">Resources, 105</a>] for primary external storage.</li> 4154 </ul> 4155 4156 <h2 id="9_6_premium_sms_warning">9.6. Premium SMS Warning</h2> 4157 4158 4159 <p>Android includes support for warning users of any outgoing premium SMS message 4160 [<a href="http://en.wikipedia.org/wiki/Short_code">Resources, 106</a>] . Premium SMS messages are text messages sent to a service registered with a 4161 carrier that may incur a charge to the user. Device implementations that 4162 declare support for android.hardware.telephony MUST warn users before sending a 4163 SMS message to numbers identified by regular expressions defined in 4164 /data/misc/sms/codes.xml file in the device. The upstream Android Open Source 4165 Project provides an implementation that satisfies this requirement.</p> 4166 4167 <h2 id="9_7_kernel_security_features">9.7. Kernel Security Features</h2> 4168 4169 4170 <p>The Android Sandbox includes features that can use the Security-Enhanced Linux 4171 (SELinux) mandatory access control (MAC) system and other security features in 4172 the Linux kernel. SELinux or any other security features, if implemented below 4173 the Android framework:</p> 4174 4175 <ul> 4176 <li>MUST maintain compatibility with existing applications.</li> 4177 <li>MUST NOT have a visible user interface when a security violation is detected 4178 and successfully blocked, but MAY have a visible user interface when an 4179 unblocked security violation occurs resulting in a successful exploit.</li> 4180 <li>SHOULD NOT be user or developer configurable.</li> 4181 </ul> 4182 4183 <p>If any API for configuration of policy is exposed to an application that can 4184 affect another application (such as a Device Administration API), the API MUST 4185 NOT allow configurations that break compatibility.</p> 4186 4187 <p>Devices MUST implement SELinux or an equivalent mandatory access control system 4188 if using a kernel other than Linux and meet the following requirements, which 4189 are satisfied by the reference implementation in the upstream Android Open 4190 Source Project.</p> 4191 4192 <p>Device implementations:</p> 4193 4194 <ul> 4195 <li>MUST support a SELinux policy that allows the SELinux mode to be set on a 4196 per-domain basis, and MUST configure all domains in enforcing mode. No 4197 permissive mode domains are allowed, including domains specific to a 4198 device/vendor.</li> 4199 <li>SHOULD load policy from /sepolicy file on the device.</li> 4200 <li>MUST NOT modify, omit, or replace the neverallow rules present within the 4201 sepolicy file provided in the upstream Android Open Source Project (AOSP) and 4202 the policy MUST compile with all neverallow present, for both AOSP SELinux 4203 domains as well as device/vendor specific domains.</li> 4204 <li>MUST support dynamic updates of the SELinux policy file without requiring a 4205 system image update.</li> 4206 </ul> 4207 4208 <p>Device implementations SHOULD retain the default SELinux policy provided in the 4209 upstream Android Open Source Project, until they have first audited their 4210 additions to the SELinux policy. Device implementations MUST be compatible with 4211 the upstream Android Open Source Project.</p> 4212 4213 <h2 id="9_8_privacy">9.8. Privacy</h2> 4214 4215 <p>If the device implements functionality in the system that captures the contents 4216 displayed on the screen and/or records the audio stream played on the device, 4217 it MUST continuously notify the user whenever this functionality is enabled and 4218 actively capturing/recording.</p> 4219 4220 <p>If a device implementation has a mechanism that routes network data traffic 4221 through a proxy server or VPN gateway by default (for example, preloading a VPN 4222 service with android.permission.CONTROL_VPN granted), the device implementation 4223 MUST ask for the user's consent before enabling that mechanism.</p> 4224 4225 <h2 id="9_9_full-disk_encryption">9.9. Full-Disk Encryption</h2> 4226 4227 <div class="note"> 4228 <p>Optional for Android device implementations without a lock screen.</p> 4229 </div> 4230 4231 4232 <p>If the device implementation supports a lock screen with PIN (numeric) or 4233 PASSWORD (alphanumeric), the device MUST support full-disk encryption of the 4234 application private data (/data partition), as well 4235 as the SD card partition if it is a permanent, non-removable part of the device 4236 [<a href="http://source.android.com/devices/tech/security/encryption/index.html">Resources, 107</a>]. For devices supporting full-disk encryption, the full-disk encryption SHOULD 4237 be enabled all the time after the user has completed the out-of-box experience. 4238 While this requirement is stated as SHOULD for this version of the Android 4239 platform, it is <strong>very strongly RECOMMENDED</strong> as we expect this to change to MUST in the future versions of Android. 4240 Encryption MUST use AES with a key of 128-bits (or greater) and a mode designed 4241 for storage (for example, AES-XTS, AES-CBC-ESSIV). The encryption key MUST NOT 4242 be written to storage at any time without being encrypted. Other than when in 4243 active use, the encryption key SHOULD be AES encrypted with the lockscreen 4244 passcode stretched using a slow stretching algorithm (e.g. PBKDF2 or scrypt). 4245 If the user has not specified a lockscreen passcode or has disabled use of the 4246 passcode for encryption, the system SHOULD use a default passcode to wrap the 4247 encryption key. If the device provides a hardware-backed keystore, the password 4248 stretching algorithm MUST be cryptographically bound to that keystore. The 4249 encryption key MUST NOT be sent off the device (even when wrapped with the user 4250 passcode and/or hardware bound key). The upstream Android Open Source project 4251 provides a preferred implementation of this feature based on the linux kernel 4252 feature dm-crypt.</p> 4253 4254 <h2 id="9_10_verified_boot">9.10. Verified Boot</h2> 4255 4256 <p> 4257 Verified boot is a feature that guarantees the integrity of the device software. 4258 If a device implementation supports the feature, it MUST:</p> 4259 <ul> 4260 <li>Declare the platform feature flag android.software.verified_boot</li> 4261 <li>Perform verification on every boot sequence</li> 4262 <li>Start verification from a hardware key that is the root of trust, and go 4263 all the way up to the system partition</li> 4264 <li>Implement each stage of verification to check the integrity and authenticity 4265 of all the bytes in the next stage before executing the code in the next stage</li> 4266 <li>Use verification algorithms as strong as current recommendations 4267 from NIST for hashing algorithms (SHA-256) and public key sizes (RSA-2048)</li> 4268 </ul> 4269 4270 <p>Device implementations SHOULD support verified boot for device integrity. 4271 While this requirement is SHOULD for this version of the Android platform, 4272 it is <strong>strongly RECOMMENDED</strong> as we expect this to change to MUST 4273 in future versions of Android. The upstream Android Open Source Project provides 4274 a preferred implementation of this feature based on the linux kernel feature dm-verity. 4275 </p> 4276 4277 <h1 id="10_software_compatibility_testing">10. Software Compatibility Testing</h1> 4278 4279 4280 <p>Device implementations MUST pass all tests described in this section.</p> 4281 4282 <p>However, note that no software test package is fully comprehensive. For this 4283 reason, device implementers are <strong>very strongly encouraged</strong> to make the minimum number of changes as possible to the reference and 4284 preferred implementation of Android available from the Android Open Source 4285 Project. This will minimize the risk of introducing bugs that create 4286 incompatibilities requiring rework and potential device updates.</p> 4287 4288 <h2 id="10_1_compatibility_test_suite">10.1. Compatibility Test Suite</h2> 4289 4290 4291 <p>Device implementations MUST pass the Android Compatibility Test Suite (CTS) [<a href="http://source.android.com/compatibility/index.html">Resources, 108</a>] available from the Android Open Source Project, using the final shipping 4292 software on the device. Additionally, device implementers SHOULD use the 4293 reference implementation in the Android Open Source tree as much as possible, 4294 and MUST ensure compatibility in cases of ambiguity in CTS and for any 4295 reimplementations of parts of the reference source code.</p> 4296 4297 <p>The CTS is designed to be run on an actual device. Like any software, the CTS 4298 may itself contain bugs. The CTS will be versioned independently of this 4299 Compatibility Definition, and multiple revisions of the CTS may be released for 4300 Android 5.1. Device implementations MUST pass the latest CTS version available 4301 at the time the device software is completed.</p> 4302 4303 <h2 id="10_2_cts_verifier">10.2. CTS Verifier</h2> 4304 4305 4306 <p>Device implementations MUST correctly execute all applicable cases in the CTS 4307 Verifier. The CTS Verifier is included with the Compatibility Test Suite, and 4308 is intended to be run by a human operator to test functionality that cannot be 4309 tested by an automated system, such as correct functioning of a camera and 4310 sensors.</p> 4311 4312 <p>The CTS Verifier has tests for many kinds of hardware, including some hardware 4313 that is optional. Device implementations MUST pass all tests for hardware that 4314 they possess; for instance, if a device possesses an accelerometer, it MUST 4315 correctly execute the Accelerometer test case in the CTS Verifier. Test cases 4316 for features noted as optional by this Compatibility Definition Document MAY be 4317 skipped or omitted.</p> 4318 4319 <p>Every device and every build MUST correctly run the CTS Verifier, as noted 4320 above. However, since many builds are very similar, device implementers are not 4321 expected to explicitly run the CTS Verifier on builds that differ only in 4322 trivial ways. Specifically, device implementations that differ from an 4323 implementation that has passed the CTS Verifier only by the set of included 4324 locales, branding, etc. MAY omit the CTS Verifier test.</p> 4325 4326 <h1 id="11_updatable_software">11. Updatable Software</h1> 4327 4328 4329 <p>Device implementations MUST include a mechanism to replace the entirety of the 4330 system software. The mechanism need not perform “live” upgrades—that is, a 4331 device restart MAY be required.</p> 4332 4333 <p>Any method can be used, provided that it can replace the entirety of the 4334 software preinstalled on the device. For instance, any of the following 4335 approaches will satisfy this requirement:</p> 4336 4337 <ul> 4338 <li>“Over-the-air (OTA)” downloads with offline update via reboot</li> 4339 <li>“Tethered” updates over USB from a host PC</li> 4340 <li>“Offline” updates via a reboot and update from a file on removable storage</li> 4341 </ul> 4342 4343 <p>However, if the device implementation includes support for an unmetered data 4344 connection such as 802.11 or Bluetooth PAN (Personal Area Network) profile:</p> 4345 4346 <ul> 4347 <li>Android Automotive implementations SHOULD support OTA downloads with offline 4348 update via reboot.</li> 4349 <li>All other device implementations MUST support OTA downloads with offline 4350 update via reboot.</li> 4351 </ul> 4352 4353 <p>The update mechanism used MUST support updates without wiping user data. That 4354 is, the update mechanism MUST preserve application private data and application 4355 shared data. Note that the upstream Android software includes an update 4356 mechanism that satisfies this requirement.</p> 4357 4358 <p>For device implementations that are launching with Android 5.1 and later, the 4359 update mechanism SHOULD support verifying that the system image is binary 4360 identical to expected result following an OTA. The block-based OTA 4361 implementation in the upstream Android Open Source Project, added since Android 4362 5.1, satisfies this requirement.</p> 4363 4364 <p>If an error is found in a device implementation after it has been released but 4365 within its reasonable product lifetime that is determined in consultation with 4366 the Android Compatibility Team to affect the compatibility of third-party 4367 applications, the device implementer MUST correct the error via a software 4368 update available that can be applied per the mechanism just described.</p> 4369 4370 <h1 id="12_document_changelog">12. Document Changelog</h1> 4371 4372 4373 <p>The following table contains a summary of the changes to the Compatibility 4374 Definition in this release. </p> 4375 <table> 4376 <tr> 4377 <th>Section</th> 4378 <th>Summary of change</th> 4379 </tr> 4380 <tr> 4381 <td>2. Device Types</td> 4382 <td>Added definition for Android automotive implementation.</td> 4383 </tr> 4384 <tr> 4385 <td>2.1 Device Configurations</td> 4386 <td>Added column for Android automotive implementation.</td> 4387 </tr> 4388 <tr> 4389 <td>3.3.2. 32-bit ARM Native Code Compatibility</td> 4390 <td>New section added.</td> 4391 </tr> 4392 <tr> 4393 <td>3.4.1. WebView Compatibility</td> 4394 <td>Updated webview user agent string requirement to accommodate upstream 4395 implementation change.</td> 4396 </tr> 4397 <tr> 4398 <td>3.4.2. Browser compatibility</td> 4399 <td>Added Android automotive implementations as another case that MAY omit a 4400 browser application.</td> 4401 </tr> 4402 <tr> 4403 <td>3.7. Runtime Compatibility</td> 4404 <td>Updated required runtime heap size for smaller screens and added requirement 4405 for the new dpi bucket (280dpi).</td> 4406 </tr> 4407 <tr> 4408 <td>3.8.3. Notifications</td> 4409 <td>Clarified notification requirement for Android Watch, Television and 4410 Automotive implementations.</td> 4411 </tr> 4412 <tr> 4413 <td>3.8.10. Lock Screen Media Control</td> 4414 <td>Clarified requirement for Android Watch and Automotive implementations.</td> 4415 </tr> 4416 <tr> 4417 <td>3.8.13. Unicode and font</td> 4418 <td>Relaxed Emoji character input method requirement.</td> 4419 </tr> 4420 <tr> 4421 <td>3.9. Device Administration</td> 4422 <td>Clarified condition when the full range of device administration policies 4423 has to be supported.</td> 4424 </tr> 4425 <tr> 4426 <td>3.10. Accessibility</td> 4427 <td>Added Android automotive requirements.</td> 4428 </tr> 4429 <tr> 4430 <td>3.11. Text-To-Speech</td> 4431 <td>Added Android automotive requirements.</td> 4432 </tr> 4433 <tr> 4434 <td>5.1. Media Codecs</td> 4435 <td>Mandated decoding support for codecs reported by CamcorderProfile.</td> 4436 </tr> 4437 <tr> 4438 <td>5.1.3 Video Codecs</td> 4439 <td>Added Android automotive requirements.</td> 4440 </tr> 4441 <tr> 4442 <td>7.1.1.3. Screen Density</td> 4443 <td>Added a new screen dpi (280dpi).</td> 4444 </tr> 4445 <tr> 4446 <td>7.1.5. Legacy Application Compatibility Mode</td> 4447 <td>Added Android automotive requirements.</td> 4448 </tr> 4449 <tr> 4450 <td>7.2 Input Devices</td> 4451 <td>Added general introduction statement.</td> 4452 </tr> 4453 <tr> 4454 <td>7.2.1. Keyboard</td> 4455 <td>Added Android Automotive requirements.</td> 4456 </tr> 4457 <tr> 4458 <td>7.2.3. Navigation Keys</td> 4459 <td>Added Android Automotive requirements.</td> 4460 </tr> 4461 <tr> 4462 <td>7.3.1. Accelerometer</td> 4463 <td>Relaxed requirement for reporting frequency on Android Watch.</td> 4464 </tr> 4465 <tr> 4466 <td>7.3.4. Gyroscope</td> 4467 <td>Relaxed requirement for reporting frequency on Android Watch.</td> 4468 </tr> 4469 <tr> 4470 <td>7.4.3 Bluetooth</td> 4471 <td>Added Android Automotive requirements.</td> 4472 </tr> 4473 <tr> 4474 <td>7.4.4. Near-Field Communications</td> 4475 <td>Clarified condition for when Host Card Emulation is a requirement.</td> 4476 </tr> 4477 <tr> 4478 <td>7.6.1. Minimum Memory and Storage</td> 4479 <td>Updated minimum memory requirements for lower resulution screen devices 4480 and added hard-limit requirement isLowRamDevice().</td> 4481 </tr> 4482 <tr> 4483 <td>7.6.2. Application Shared Storage</td> 4484 <td>Updated requirements when support for host machine access is mandatory.</td> 4485 </tr> 4486 <tr> 4487 <td>7.8.1. Microphone</td> 4488 <td>Added Android Automotive requirements.</td> 4489 </tr> 4490 <tr> 4491 <td>8.2. File I/O Access Performance</td> 4492 <td>Clarified requirements.</td> 4493 </tr> 4494 <tr> 4495 <td>9.8. Privacy</td> 4496 <td>Added privacy requirement for preloaded VPNs.</td> 4497 </tr> 4498 <tr> 4499 <td>9.9. Full-Disk Encryption</td> 4500 <td>Clarified condition when Full-Disk encryption support is mandatory.</td> 4501 </tr> 4502 <tr> 4503 <td>9.10. Verified Boot</td> 4504 <td>Clarified definition of verified boot.</td> 4505 </tr> 4506 <tr> 4507 <td>11. Updatable Software</td> 4508 <td>Clarified the OTA download requirement is allowed but not mandatory for 4509 Android Automotive implementations.</td> 4510 </tr> 4511 </table> 4512 4513 4514 <h1 id="13_contact_us">13. Contact Us</h1> 4515 4516 4517 <p>You can join the android-compatibility forum <a href="https://groups.google.com/forum/#!forum/android-compatibility">[Resources, 109</a>] and ask for clarifications or bring up any issues that you think the document 4518 does not cover.</p> 4519 4520 <h1 id="14_resources">14. Resources</h1> 4521 4522 4523 <p>1. IETF RFC2119 Requirement Levels: <a href="http://www.ietf.org/rfc/rfc2119.txt">http://www.ietf.org/rfc/rfc2119.txt</a></p> 4524 4525 <p>2. Android Open Source Project: <a href="http://source.android.com/">http://source.android.com/</a></p> 4526 4527 <p>3. Android Television features: <a href="http://developer.android.com/reference/android/content/pm/PackageManager.html#FEATURE_LEANBACK">http://developer.android.com/reference/android/content/pm/PackageManager.html#FEATURE_LEANBACK</a> </p> 4528 4529 <p>4. Android Watch feature: <a href="http://developer.android.com/reference/android/content/res/Configuration.html#UI_MODE_TYPE_WATCH">http://developer.android.com/reference/android/content/res/Configuration.html#UI_MODE_TYPE_WATCH</a></p> 4530 4531 <p>5. API definitions and documentation: <a href="http://developer.android.com/reference/packages.html">http://developer.android.com/reference/packages.html</a></p> 4532 4533 <p>6. Android Permissions reference: <a href="http://developer.android.com/reference/android/Manifest.permission.html">http://developer.android.com/reference/android/Manifest.permission.html</a></p> 4534 4535 <p>7. android.os.Build reference: <a href="http://developer.android.com/reference/android/os/Build.html">http://developer.android.com/reference/android/os/Build.html</a></p> 4536 4537 <p>8. Android 5.1 allowed version strings: <a href="http://source.android.com/compatibility/5.1/versions.html">http://source.android.com/compatibility/5.1/versions.html</a></p> 4538 4539 <p>9. Telephony Provider: <a href="http://developer.android.com/reference/android/provider/Telephony.html">http://developer.android.com/reference/android/provider/Telephony.html</a></p> 4540 4541 <p>10. Host-based Card Emulation: <a href="http://developer.android.com/guide/topics/connectivity/nfc/hce.html">http://developer.android.com/guide/topics/connectivity/nfc/hce.html</a></p> 4542 4543 <p>11. Android Extension Pack: <a href="http://developer.android.com/guide/topics/graphics/opengl.html#aep">http://developer.android.com/guide/topics/graphics/opengl.html#aep</a> </p> 4544 4545 <p>12. android.webkit.WebView class: <a href="http://developer.android.com/reference/android/webkit/WebView.html">http://developer.android.com/reference/android/webkit/WebView.html</a></p> 4546 4547 <p>13. WebView compatibility: <a href="http://www.chromium.org/">http://www.chromium.org/</a></p> 4548 4549 <p>14. HTML5: <a href="http://html.spec.whatwg.org/multipage/">http://html.spec.whatwg.org/multipage/</a></p> 4550 4551 <p>15. HTML5 offline capabilities:<a href="http://dev.w3.org/html5/spec/Overview.html#offline"> http://dev.w3.org/html5/spec/Overview.html#offline</a></p> 4552 4553 <p>16. HTML5 video tag: <a href="http://dev.w3.org/html5/spec/Overview.html#video">http://dev.w3.org/html5/spec/Overview.html#video</a></p> 4554 4555 <p>17. HTML5/W3C geolocation API: <a href="http://www.w3.org/TR/geolocation-API/">http://www.w3.org/TR/geolocation-API/</a></p> 4556 4557 <p>18. HTML5/W3C webstorage API: <a href="http://www.w3.org/TR/webstorage/">http://www.w3.org/TR/webstorage/</a></p> 4558 4559 <p>19. HTML5/W3C IndexedDB API: <a href="http://www.w3.org/TR/IndexedDB/">http://www.w3.org/TR/IndexedDB/</a></p> 4560 4561 <p>20. Dalvik Executable Format and bytecode specification: available in the 4562 Android source code, at dalvik/docs</p> 4563 4564 <p>21. AppWidgets: <a href="http://developer.android.com/guide/practices/ui_guidelines/widget_design.html">http://developer.android.com/guide/practices/ui_guidelines/widget_design.html</a></p> 4565 4566 <p>22. Notifications: <a href="http://developer.android.com/guide/topics/ui/notifiers/notifications.html">http://developer.android.com/guide/topics/ui/notifiers/notifications.html</a></p> 4567 4568 <p>23. Application Resources: <a href="https://developer.android.com/guide/topics/resources/available-resources.html">https://developer.android.com/guide/topics/resources/available-resources.html</a></p> 4569 4570 <p>24. Status Bar icon style guide: <a href="http://developer.android.com/design/style/iconography.html">http://developer.android.com/design/style/iconography.html</a></p> 4571 4572 <p>25. Notifications Resources: <a href="https://developer.android.com/design/patterns/notifications.html">https://developer.android.com/design/patterns/notifications.html</a> </p> 4573 4574 <p>26. Search Manager: <a href="http://developer.android.com/reference/android/app/SearchManager.html">http://developer.android.com/reference/android/app/SearchManager.html</a> </p> 4575 4576 <p>27. Toasts: <a href="http://developer.android.com/reference/android/widget/Toast.html">http://developer.android.com/reference/android/widget/Toast.html</a></p> 4577 4578 <p>28. Themes: <a href="http://developer.android.com/guide/topics/ui/themes.html">http://developer.android.com/guide/topics/ui/themes.html</a></p> 4579 4580 <p>29. R.style class: <a href="http://developer.android.com/reference/android/R.style.html">http://developer.android.com/reference/android/R.style.html</a></p> 4581 4582 <p>30. Material design: <a href="http://developer.android.com/reference/android/R.style.html#Theme_Material">http://developer.android.com/reference/android/R.style.html#Theme_Material</a> </p> 4583 4584 <p>31. Live Wallpapers: <a href="http://developer.android.com/reference/android/service/wallpaper/WallpaperService.html">http://developer.android.com/reference/android/service/wallpaper/WallpaperService.html</a></p> 4585 4586 <p>32. Overview screen resources: <a href="http://developer.android.com/guide/components/recents.html">http://developer.android.com/guide/components/recents.html</a> </p> 4587 4588 <p>33. Screen pinning: <a href="https://developer.android.com/about/versions/android-5.0.html#ScreenPinning">https://developer.android.com/about/versions/android-5.0.html#ScreenPinning</a> </p> 4589 4590 <p>34. Input methods: <a href="http://developer.android.com/guide/topics/text/creating-input-method.html">http://developer.android.com/guide/topics/text/creating-input-method.html</a> </p> 4591 4592 <p>35. Media Notification: <a href="https://developer.android.com/reference/android/app/Notification.MediaStyle.html">https://developer.android.com/reference/android/app/Notification.MediaStyle.html</a></p> 4593 4594 <p>36. Dreams: <a href="http://developer.android.com/reference/android/service/dreams/DreamService.html">http://developer.android.com/reference/android/service/dreams/DreamService.html</a></p> 4595 4596 <p>37. Settings.Secure LOCATION_MODE:</p> 4597 4598 <p><a href="http://developer.android.com/reference/android/provider/Settings.Secure.html#LOCATION_MODE">http://developer.android.com/reference/android/provider/Settings.Secure.html#LOCATION_MODE</a></p> 4599 4600 <p>38. Unicode 6.1.0: <a href="http://www.unicode.org/versions/Unicode6.1.0/">http://www.unicode.org/versions/Unicode6.1.0/</a></p> 4601 4602 <p>39. Android Device Administration: <a href="http://developer.android.com/guide/topics/admin/device-admin.html">http://developer.android.com/guide/topics/admin/device-admin.html</a></p> 4603 4604 <p>40. DevicePolicyManager reference: <a href="http://developer.android.com/reference/android/app/admin/DevicePolicyManager.html">http://developer.android.com/reference/android/app/admin/DevicePolicyManager.html</a></p> 4605 4606 <p>41. Android Device Owner App:</p> 4607 4608 <p><a href="http://developer.android.com/reference/android/app/admin/DevicePolicyManager.html#isDeviceOwnerApp(java.lang.String)">http://developer.android.com/reference/android/app/admin/DevicePolicyManager.html#isDeviceOwnerApp(java.lang.String)</a></p> 4609 4610 <p>42. Android Accessibility Service APIs: <a href="http://developer.android.com/reference/android/accessibilityservice/AccessibilityService.html">http://developer.android.com/reference/android/accessibilityservice/AccessibilityService.html</a></p> 4611 4612 <p>43. Android Accessibility APIs: <a href="http://developer.android.com/reference/android/view/accessibility/package-summary.html">http://developer.android.com/reference/android/view/accessibility/package-summary.html</a></p> 4613 4614 <p>44. Eyes Free project: <a href="http://code.google.com/p/eyes-free/">http://code.google.com/p/eyes-free</a></p> 4615 4616 <p>45. Text-To-Speech APIs: <a href="http://developer.android.com/reference/android/speech/tts/package-summary.html">http://developer.android.com/reference/android/speech/tts/package-summary.html</a></p> 4617 4618 <p>46. Television Input Framework: <a href="https://source.android.com/devices/tv/index.html">https://source.android.com/devices/tv/index.html</a></p> 4619 4620 <p>47. Reference tool documentation (for adb, aapt, ddms, systrace): <a href="http://developer.android.com/tools/help/index.html">http://developer.android.com/tools/help/index.html</a></p> 4621 4622 <p>48. Android apk file description: <a href="http://developer.android.com/guide/components/fundamentals.html">http://developer.android.com/guide/components/fundamentals.html </a></p> 4623 4624 <p>49. Manifest files: <a href="http://developer.android.com/guide/topics/manifest/manifest-intro.html">http://developer.android.com/guide/topics/manifest/manifest-intro.html</a></p> 4625 4626 <p>50. Android Media Formats: <a href="http://developer.android.com/guide/appendix/media-formats.html">http://developer.android.com/guide/appendix/media-formats.html</a></p> 4627 4628 <p>51. RTC Hardware Coding Requirements: <a href="http://www.webmproject.org/hardware/rtc-coding-requirements/">http://www.webmproject.org/hardware/rtc-coding-requirements/</a></p> 4629 4630 <p>52. AudioEffect API: <a href="http://developer.android.com/reference/android/media/audiofx/AudioEffect.html">http://developer.android.com/reference/android/media/audiofx/AudioEffect.html</a></p> 4631 4632 <p>53. Android android.content.pm.PackageManager class and Hardware Features List:</p> 4633 4634 <p><a href="http://developer.android.com/reference/android/content/pm/PackageManager.html">http://developer.android.com/reference/android/content/pm/PackageManager.html</a></p> 4635 4636 <p>54. HTTP Live Streaming Draft Protocol: <a href="http://tools.ietf.org/html/draft-pantos-http-live-streaming-03">http://tools.ietf.org/html/draft-pantos-http-live-streaming-03</a></p> 4637 4638 <p>55. ADB: <a href="http://developer.android.com/tools/help/adb.html">http://developer.android.com/tools/help/adb.html</a> </p> 4639 4640 <p>56. Dumpsys: <a href="https://source.android.com/devices/input/diagnostics.html">https://source.android.com/devices/input/diagnostics.html</a> </p> 4641 4642 <p>57. DDMS: <a href="http://developer.android.com/tools/debugging/ddms.html">http://developer.android.com/tools/debugging/ddms.html</a> </p> 4643 4644 <p>58. Monkey testing tool: <a href="http://developer.android.com/tools/help/monkey.html">http://developer.android.com/tools/help/monkey.html</a> </p> 4645 4646 <p>59. SysyTrace tool: <a href="http://developer.android.com/tools/help/systrace.html">http://developer.android.com/tools/help/systrace.html</a></p> 4647 4648 <p>60. Android Application Development-Related Settings:</p> 4649 4650 <p><a href="http://developer.android.com/reference/android/provider/Settings.html#ACTION_APPLICATION_DEVELOPMENT_SETTINGS">http://developer.android.com/reference/android/provider/Settings.html#ACTION_APPLICATION_DEVELOPMENT_SETTINGS</a></p> 4651 4652 <p>61. Supporting Multiple Screens: <a href="http://developer.android.com/guide/practices/screens_support.html">http://developer.android.com/guide/practices/screens_support.html</a></p> 4653 4654 <p>62. android.util.DisplayMetrics: <a href="http://developer.android.com/reference/android/util/DisplayMetrics.html">http://developer.android.com/reference/android/util/DisplayMetrics.html</a></p> 4655 4656 <p>63. RenderScript: <a href="http://developer.android.com/guide/topics/renderscript/">http://developer.android.com/guide/topics/renderscript/</a></p> 4657 4658 <p>64. Android extension pack for OpenGL ES: <a href="https://developer.android.com/reference/android/opengl/GLES31Ext.html">https://developer.android.com/reference/android/opengl/GLES31Ext.html</a> </p> 4659 4660 <p>65. Hardware Acceleration: <a href="http://developer.android.com/guide/topics/graphics/hardware-accel.html">http://developer.android.com/guide/topics/graphics/hardware-accel.html</a></p> 4661 4662 <p>66. EGL Extension-EGL_ANDROID_RECORDABLE:</p> 4663 4664 <p><a href="http://www.khronos.org/registry/egl/extensions/ANDROID/EGL_ANDROID_recordable.txt">http://www.khronos.org/registry/egl/extensions/ANDROID/EGL_ANDROID_recordable.txt</a></p> 4665 4666 <p>67. Display Manager: <a href="http://developer.android.com/reference/android/hardware/display/DisplayManager.html">http://developer.android.com/reference/android/hardware/display/DisplayManager.html</a></p> 4667 4668 <p>68. android.content.res.Configuration: <a href="http://developer.android.com/reference/android/content/res/Configuration.html">http://developer.android.com/reference/android/content/res/Configuration.html</a></p> 4669 4670 <p>69. Action Assist: <a href="http://developer.android.com/reference/android/content/Intent.html#ACTION_ASSIST">http://developer.android.com/reference/android/content/Intent.html#ACTION_ASSIST</a></p> 4671 4672 <p>70. Touch Input Configuration: <a href="http://source.android.com/devices/tech/input/touch-devices.html">http://source.android.com/devices/tech/input/touch-devices.html</a></p> 4673 4674 <p>71. Motion Event API: <a href="http://developer.android.com/reference/android/view/MotionEvent.html">http://developer.android.com/reference/android/view/MotionEvent.html</a></p> 4675 4676 <p>72. Key Event API: <a href="http://developer.android.com/reference/android/view/KeyEvent.html">http://developer.android.com/reference/android/view/KeyEvent.html</a> </p> 4677 4678 <p>73. Android Open Source sensors: <a href="http://source.android.com/devices/sensors/">http://source.android.com/devices/sensors</a></p> 4679 4680 <p>74. android.hardware.SensorEvent: <a href="http://developer.android.com/reference/android/hardware/SensorEvent.html">http://developer.android.com/reference/android/hardware/SensorEvent.html</a></p> 4681 4682 <p>75. Timestamp sensor event: <a href="http://developer.android.com/reference/android/hardware/SensorEvent.html#timestamp">http://developer.android.com/reference/android/hardware/SensorEvent.html#timestamp</a></p> 4683 4684 <p>76. Android Open Source composite sensors: <a href="http://source.android.com/devices/sensors/sensor-types.html#composite_sensor_type_summary">https://source.android.com/devices/sensors/sensor-types.html#composite_sensor_type_summary</a></p> 4685 4686 <p>77. Continuous trigger mode: <a href="http://source.android.com/devices/sensors/report-modes.html#continuous">https://source.android.com/devices/sensors/report-modes.html#continuous</a></p> 4687 4688 <p>78. Accelerometer sensor: <a href="http://developer.android.com/reference/android/hardware/Sensor.html#TYPE_ACCELEROMETER">http://developer.android.com/reference/android/hardware/Sensor.html#TYPE_ACCELEROMETER</a></p> 4689 4690 <p>79. Wi-Fi Multicast API: <a href="http://developer.android.com/reference/android/net/wifi/WifiManager.MulticastLock.html">http://developer.android.com/reference/android/net/wifi/WifiManager.MulticastLock.html</a></p> 4691 4692 <p>80. Wi-Fi Direct (Wi-Fi P2P): <a href="http://developer.android.com/reference/android/net/wifi/p2p/WifiP2pManager.html">http://developer.android.com/reference/android/net/wifi/p2p/WifiP2pManager.html</a></p> 4693 4694 <p>81. WifiManager API: <a href="http://developer.android.com/reference/android/net/wifi/WifiManager.html">http://developer.android.com/reference/android/net/wifi/WifiManager.html</a></p> 4695 4696 <p>82. Bluetooth API: <a href="http://developer.android.com/reference/android/bluetooth/package-summary.html">http://developer.android.com/reference/android/bluetooth/package-summary.html</a></p> 4697 4698 <p>83. Bluetooth ScanFilter API: <a href="https://developer.android.com/reference/android/bluetooth/le/ScanFilter.html">https://developer.android.com/reference/android/bluetooth/le/ScanFilter.html</a></p> 4699 4700 <p>84. NDEF Push Protocol: <a href="http://source.android.com/compatibility/ndef-push-protocol.pdf">http://source.android.com/compatibility/ndef-push-protocol.pdf</a></p> 4701 4702 <p>85. Android Beam: <a href="http://developer.android.com/guide/topics/connectivity/nfc/nfc.html">http://developer.android.com/guide/topics/connectivity/nfc/nfc.html</a> </p> 4703 4704 <p>86. Android NFC Sharing Settings:</p> 4705 4706 <p><a href="http://developer.android.com/reference/android/provider/Settings.html#ACTION_NFCSHARING_SETTINGS">http://developer.android.com/reference/android/provider/Settings.html#ACTION_NFCSHARING_SETTINGS</a></p> 4707 4708 <p>87. NFC Connection Handover: <a href="http://members.nfc-forum.org/specs/spec_list/#conn_handover">http://members.nfc-forum.org/specs/spec_list/#conn_handover</a></p> 4709 4710 <p>88. Bluetooth Secure Simple Pairing Using NFC: <a href="http://members.nfc-forum.org/apps/group_public/download.php/18688/NFCForum-AD-BTSSP_1_1.pdf">http://members.nfc-forum.org/apps/group_public/download.php/18688/NFCForum-AD-BTSSP_1_1.pdf</a> </p> 4711 4712 <p>89. Content Resolver: <a href="http://developer.android.com/reference/android/content/ContentResolver.html">http://developer.android.com/reference/android/content/ContentResolver.html</a></p> 4713 4714 <p>90. Camera orientation API: <a href="http://developer.android.com/reference/android/hardware/Camera.html#setDisplayOrientation(int)">http://developer.android.com/reference/android/hardware/Camera.html#setDisplayOrientation(int)</a></p> 4715 4716 <p>91. Camera: <a href="http://developer.android.com/reference/android/hardware/Camera.html">http://developer.android.com/reference/android/hardware/Camera.html</a></p> 4717 4718 <p>92. Camera: <a href="http://developer.android.com/reference/android/hardware/Camera.Parameters.html">http://developer.android.com/reference/android/hardware/Camera.Parameters.html</a></p> 4719 4720 <p>93. Camera hardware level: <a href="https://developer.android.com/reference/android/hardware/camera2/CameraCharacteristics.html#INFO_SUPPORTED_HARDWARE_LEVEL">https://developer.android.com/reference/android/hardware/camera2/CameraCharacteristics.html#INFO_SUPPORTED_HARDWARE_LEVEL</a> </p> 4721 4722 <p>94. Camera version support: <a href="http://source.android.com/devices/camera/versioning.html">http://source.android.com/devices/camera/versioning.html</a> </p> 4723 4724 <p>95. Android DownloadManager: <a href="http://developer.android.com/reference/android/app/DownloadManager.html">http://developer.android.com/reference/android/app/DownloadManager.html</a></p> 4725 4726 <p>96. Android File Transfer: <a href="http://www.android.com/filetransfer">http://www.android.com/filetransfer</a></p> 4727 4728 <p>97. Android Open Accessories: <a href="http://developer.android.com/guide/topics/connectivity/usb/accessory.html">http://developer.android.com/guide/topics/connectivity/usb/accessory.html</a></p> 4729 4730 <p>98. Android USB Audio: <a href="http://developer.android.com/reference/android/hardware/usb/UsbConstants.html#USB_CLASS_AUDIO">http://developer.android.com/reference/android/hardware/usb/UsbConstants.html#USB_CLASS_AUDIO</a></p> 4731 4732 <p>99. USB Charging Specification: <a href="http://www.usb.org/developers/docs/devclass_docs/USB_Battery_Charging_1.2.pdf">http://www.usb.org/developers/docs/devclass_docs/USB_Battery_Charging_1.2.pdf</a></p> 4733 4734 <p>100. USB Host API:<a href="http://developer.android.com/guide/topics/connectivity/usb/host.html"> http://developer.android.com/guide/topics/connectivity/usb/host.html</a></p> 4735 4736 <p>101. Wired audio headset: <a href="http://source.android.com/accessories/headset-spec.html">http://source.android.com/accessories/headset-spec.html</a> </p> 4737 4738 <p>102. Android Security and Permissions reference: <a href="http://developer.android.com/guide/topics/security/permissions.html">http://developer.android.com/guide/topics/security/permissions.html</a></p> 4739 4740 <p>103. UserManager reference: <a href="http://developer.android.com/reference/android/os/UserManager.html">http://developer.android.com/reference/android/os/UserManager.html</a></p> 4741 4742 <p>104. External Storage reference: <a href="http://source.android.com/devices/storage">http://source.android.com/devices/storage</a></p> 4743 4744 <p>105. External Storage APIs: <a href="http://developer.android.com/reference/android/os/Environment.html">http://developer.android.com/reference/android/os/Environment.html</a></p> 4745 4746 <p>106. SMS Short Code: <a href="http://en.wikipedia.org/wiki/Short_code">http://en.wikipedia.org/wiki/Short_code</a></p> 4747 4748 <p>107. Android Open Source Encryption: <a href="http://source.android.com/devices/tech/security/encryption/index.html">http://source.android.com/devices/tech/security/encryption/index.html</a></p> 4749 4750 <p>108. Android Compatibility Program Overview: <a href="http://source.android.com/compatibility/index.html">http://source.android.com/compatibility/index.html</a></p> 4751 4752 <p>109. Android Compatibility forum: <a href="https://groups.google.com/forum/#!forum/android-compatibility">https://groups.google.com/forum/#!forum/android-compatibility</a></p> 4753 4754 <p>110. WebM project: <a href="http://www.webmproject.org/">http://www.webmproject.org/</a> </p> 4755 4756 <p>111. Android UI_MODE_TYPE_CAR API: <a href="http://developer.android.com/reference/android/content/res/Configuration.html#UI_MODE_TYPE_CAR">http://developer.android.com/reference/android/content/res/Configuration.html#UI_MODE_TYPE_CAR</a></p> 4757 4758 <p>112. Android MediaCodecList API: <a href="http://developer.android.com/reference/android/media/MediaCodecList.html">http://developer.android.com/reference/android/media/MediaCodecList.html</a></p> 4759 4760 <p>113. Android CamcorderProfile API: <a href="http://developer.android.com/reference/android/media/CamcorderProfile.html">http://developer.android.com/reference/android/media/CamcorderProfile.html</a></p> 4761 4762 <p>Many of these resources are derived directly or indirectly from the Android 4763 SDK, and will be functionally identical to the information in that SDK’s 4764 documentation. In any cases where this Compatibility Definition or the 4765 Compatibility Test Suite disagrees with the SDK documentation, the SDK 4766 documentation is considered authoritative. Any technical details provided in 4767 the references included above are considered by inclusion to be part of this 4768 Compatibility Definition.</p> 4769 4770 </div> 4771 </body> 4772 </html> 4773
