1 <?xml version="1.0" encoding="UTF-8"?> 2 <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd"> 3 <html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en"> 4 <head> 5 <title>Android 4.4 Compatibility Definition</title> 6 <link rel="stylesheet" type="text/css" href="cdd.css"/> 7 </head> 8 <body> 9 <div><img src="header.jpg" alt="Android logo"/></div> 10 <h1>Android 4.4 Compatibility Definition</h1> 11 <!-- 12 <span style="color: red; font-weight: bold;"><h2>Revision 1</h2></span><br/> 13 <span style="color: red;">Last updated: July 23, 2013</span> 14 --> 15 <p><b><font color="red">Revision 1</font></b><br/> 16 Last updated: November 27, 2013 17 </p> 18 <p>Copyright © 2013, Google Inc. All rights reserved.<br/> 19 <a href="mailto:compatibility (a] android.com">compatibility (a] android.com</a> 20 </p> 21 22 <h2>Table of Contents</h2> 23 <div style="margin-left: 2em;"> 24 <a href="#section-1">1. Introduction</a><br/> 25 <a href="#section-2">2. Resources</a><br/> 26 <a href="#section-3">3. Software</a><br/> 27 <div style="margin-left: 2em;"> 28 <a href="#section-3.1">3.1. Managed API Compatibility</a><br/> 29 <a href="#section-3.2">3.2. Soft API Compatibility</a><br/> 30 <div style="margin-left: 2em;"> 31 <a href="#section-3.2.1">3.2.1. Permissions</a><br/> 32 <a href="#section-3.2.2">3.2.2. Build Parameters</a><br/> 33 <a href="#section-3.2.3">3.2.3. Intent Compatibility</a><br/> 34 <div style="margin-left: 2em;"> 35 <a href="#section-3.2.3.1">3.2.3.1. Core Application Intents</a><br/> 36 <a href="#section-3.2.3.2">3.2.3.2. Intent Overrides</a><br/> 37 <a href="#section-3.2.3.3">3.2.3.3. Intent Namespaces</a><br/> 38 <a href="#section-3.2.3.4">3.2.3.4. Broadcast Intents</a><br/> 39 <a href="#section-3.2.3.5">3.2.3.5. Default App Settings</a><br/> 40 </div> 41 </div> 42 <a href="#section-3.3">3.3. Native API Compatibility</a><br/> 43 <div style="margin-left: 2em;"> 44 <a href="#section-3.3.1">3.3.1 Application Binary Interfaces</a><br/> 45 </div> 46 <a href="#section-3.4">3.4. Web Compatibility</a><br/> 47 <div style="margin-left: 2em;"> 48 <a href="#section-3.4.1">3.4.1. WebView Compatibility</a><br/> 49 <a href="#section-3.4.2">3.4.2. Browser Compatibility</a><br/> 50 </div> 51 <a href="#section-3.5">3.5. API Behavioral Compatibility</a><br/> 52 <a href="#section-3.6">3.6. API Namespaces</a><br/> 53 <a href="#section-3.7">3.7. Virtual Machine Compatibility</a><br/> 54 <a href="#section-3.8">3.8. User Interface Compatibility</a><br/> 55 <div style="margin-left: 2em;"> 56 <a href="#section-3.8.1">3.8.1. Launcher (Home Screen)</a><br/> 57 <a href="#section-3.8.2">3.8.2. Widgets</a><br/> 58 <a href="#section-3.8.3">3.8.3. Notifications</a><br/> 59 <a href="#section-3.8.4">3.8.4. Search</a><br/> 60 <a href="#section-3.8.5">3.8.5. Toasts</a><br/> 61 <a href="#section-3.8.6">3.8.6. Themes</a><br/> 62 <a href="#section-3.8.7">3.8.7. Live Wallpapers</a><br/> 63 <a href="#section-3.8.8">3.8.8. Recent Application Display</a><br/> 64 <a href="#section-3.8.9">3.8.9. Input Management</a><br/> 65 <a href="#section-3.8.10">3.8.10. Lock Screen Media Remote Control</a><br/> 66 <a href="#section-3.8.11">3.8.11. Dreams</a><br/> 67 <a href="#section-3.8.12">3.8.12. Location</a><br/> 68 <a href="#section-3.8.13">3.8.13. Unicode</a><br/> 69 </div> 70 <a href="#section-3.9">3.9 Device Administration</a><br/> 71 <a href="#section-3.10">3.10 Accessibility</a><br/> 72 <a href="#section-3.11">3.11 Text-to-Speech</a><br/> 73 </div> 74 <a href="#section-4">4. Application Packaging Compatibility</a><br/> 75 <a href="#section-5">5. Multimedia Compatibility</a><br/> 76 <div style="margin-left: 2em;"> 77 <a href="#section-5.1">5.1. Media Codecs</a><br/> 78 <a href="#section-5.2">5.2. Video Encoding</a><br/> 79 <a href="#section-5.3">5.3. Video Decoding</a><br/> 80 <a href="#section-5.4">5.4. Audio Recording</a><br/> 81 <a href="#section-5.5">5.5. Audio Latency</a><br/> 82 <a href="#section-5.6">5.6. Network Protocols</a><br/> 83 </div> 84 <a href="#section-6">6. Developer Tools and Options Compatibility</a><br/> 85 <div style="margin-left: 2em;"> 86 <a href="#section-6.1">6.1. Developer Tools</a><br/> 87 <a href="#section-6.2">6.2. Developer Options</a><br/> 88 <a href="#section-6.2.1">6.2.1. Experimental</a><br/> 89 </div> 90 <a href="#section-7">7. Hardware Compatibility</a><br/> 91 <div style="margin-left: 2em;"> 92 <a href="#section-7.1">7.1. Display and Graphics</a><br/> 93 <div style="margin-left: 2em;"> 94 <a href="#section-7.1.1">7.1.1. Screen Configuration</a><br/> 95 <a href="#section-7.1.2">7.1.2. Display Metrics</a><br/> 96 <a href="#section-7.1.3">7.1.3. Screen Orientation</a><br/> 97 <a href="#section-7.1.4">7.1.4. 2D and 3D Graphics Acceleration</a><br/> 98 <a href="#section-7.1.5">7.1.5. Legacy Application Compatibility Mode</a><br/> 99 <a href="#section-7.1.6">7.1.6. Screen Types</a><br/> 100 <a href="#section-7.1.7">7.1.7. Screen Technology</a><br/> 101 <a href="#section-7.1.8">7.1.8. External Displays</a><br/> 102 </div> 103 <a href="#section-7.2">7.2. Input Devices</a><br/> 104 <div style="margin-left: 2em;"> 105 <a href="#section-7.2.1">7.2.1. Keyboard</a><br/> 106 <a href="#section-7.2.2">7.2.2. Non-touch Navigation</a><br/> 107 <a href="#section-7.2.3">7.2.3. Navigation keys</a><br/> 108 <a href="#section-7.2.4">7.2.4. Touchscreen input</a><br/> 109 <a href="#section-7.2.5">7.2.5. Fake touch input</a><br/> 110 <a href="#section-7.2.6">7.2.6. Microphone</a><br/> 111 </div> 112 <a href="#section-7.3">7.3. Sensors</a><br/> 113 <div style="margin-left: 2em;"> 114 <a href="#section-7.3.1">7.3.1. Accelerometer</a><br/> 115 <a href="#section-7.3.2">7.3.2. Magnetometer</a><br/> 116 <a href="#section-7.3.3">7.3.3. GPS</a><br/> 117 <a href="#section-7.3.4">7.3.4. Gyroscope</a><br/> 118 <a href="#section-7.3.5">7.3.5. Barometer</a><br/> 119 <a href="#section-7.3.6">7.3.6. Thermometer</a><br/> 120 <a href="#section-7.3.7">7.3.7. Photometer</a><br/> 121 <a href="#section-7.3.8">7.3.8. Proximity Sensor</a><br/> 122 </div> 123 <a href="#section-7.4">7.4. Data Connectivity</a><br/> 124 <div style="margin-left: 2em;"> 125 <a href="#section-7.4.1">7.4.1. Telephony</a><br/> 126 <a href="#section-7.4.2">7.4.2. IEEE 802.11 (Wi-Fi)</a><br/> 127 <div style="margin-left: 2em;"> 128 <a href="#section-7.4.2.1">7.4.2.1. Wi-Fi Direct</a><br/> 129 <a href="#section-7.4.2.2">7.4.2.2. Wi-Fi Tunneled Direct Link Setup</a><br/> 130 </div> 131 <a href="#section-7.4.3">7.4.3. Bluetooth</a><br/> 132 <a href="#section-7.4.4">7.4.4. Near-Field Communications</a><br/> 133 <a href="#section-7.4.5">7.4.5. Minimum Network Capability</a><br/> 134 <a href="#section-7.4.6">7.4.6. Sync Settings</a><br/> 135 </div> 136 <a href="#section-7.5">7.5. Cameras</a><br/> 137 <div style="margin-left: 2em;"> 138 <a href="#section-7.5.1">7.5.1. Rear-Facing Camera</a><br/> 139 <a href="#section-7.5.2">7.5.2. Front-Facing Camera</a><br/> 140 <a href="#section-7.5.3">7.5.3. Camera API Behavior</a><br/> 141 <a href="#section-7.5.4">7.5.4. Camera Orientation</a><br/> 142 </div> 143 <a href="#section-7.6">7.6. Memory and Storage</a><br/> 144 <div style="margin-left: 2em;"> 145 <a href="#section-7.6.1">7.6.1. Minimum Memory and Storage</a><br/> 146 <a href="#section-7.6.2">7.6.2. Shared External Storage</a><br/> 147 </div> 148 <a href="#section-7.7">7.7. USB</a><br/> 149 </div> 150 <a href="#section-8">8. Performance Compatibility</a><br/> 151 <a href="#section-9">9. Security Model Compatibility</a><br/> 152 <div style="margin-left: 2em;"> 153 <a href="#section-9.1">9.1. Permissions</a><br/> 154 <a href="#section-9.2">9.2. UID and Process Isolation</a><br/> 155 <a href="#section-9.3">9.3. Filesystem Permissions</a><br/> 156 <a href="#section-9.4">9.4. Alternate Execution Environments</a><br/> 157 <a href="#section-9.5">9.5. Multi-User Support</a><br/> 158 <a href="#section-9.6">9.6. Premium SMS Warning</a><br/> 159 <a href="#section-9.7">9.7. Kernel Security Features</a><br/> 160 <a href="#section-9.8">9.8. Privacy</a><br/> 161 <a href="#section-9.9">9.9. Full-Disk Encryption</a><br/> 162 </div> 163 <a href="#section-10">10. Software Compatibility Testing</a><br/> 164 <div style="margin-left: 2em;"> 165 <a href="#section-10.1">10.1. Compatibility Test Suite</a><br/> 166 <a href="#section-10.2">10.2. CTS Verifier</a><br/> 167 <a href="#section-10.3">10.3. Reference Applications</a><br/> 168 </div> 169 <a href="#section-11">11. Updatable Software</a><br/> 170 <a href="#section-12">12. Document Changelog</a><br/> 171 <a href="#section-13">13. Contact Us</a><br/> 172 </div> 173 174 <div style="page-break-before: always;"></div> 175 176 <a name="section-1"></a><h2 id="section-1">1. Introduction</h2> 177 <p>This document enumerates the requirements that must be met in order for 178 devices to be compatible with Android 4.4.</p> 179 <p>The use of "must", "must not", "required", "shall", "shall not", "should", 180 "should not", "recommended", "may" and "optional" is per the IETF standard 181 defined in RFC2119 [<a href="#resources01">Resources, 1</a>].</p> 182 <p>As used in this document, a "device implementer" or "implementer" is a 183 person or organization developing a hardware/software solution running Android 184 4.4. A "device implementation" or "implementation" is the hardware/software 185 solution so developed.</p> 186 <p>To be considered compatible with Android 4.4, device implementations 187 MUST meet the requirements presented in this Compatibility Definition, 188 including any documents incorporated via reference.</p> 189 <p>Where this definition or the software tests described in <a 190 href="#section-10">Section 10</a> is silent, ambiguous, or incomplete, it is 191 the responsibility of the device implementer to ensure compatibility with 192 existing implementations.</p> 193 <p>For this reason, the Android Open Source Project [<a 194 href="#resources03">Resources, 3</a>] is both the reference and preferred 195 implementation of Android. Device implementers are strongly encouraged to base 196 their implementations to the greatest extent possible on the "upstream" source 197 code available from the Android Open Source Project. While some components can 198 hypothetically be replaced with alternate implementations this practice is 199 strongly discouraged, as passing the software tests will become substantially 200 more difficult. It is the implementer's responsibility to ensure full 201 behavioral compatibility with the standard Android implementation, including 202 and beyond the Compatibility Test Suite. Finally, note that certain component 203 substitutions and modifications are explicitly forbidden by this document.</p> 204 <a name="section-2"></a><h2 id="section-2">2. Resources</h2> 205 <ol> 206 <a name="resources01"></a><li id="resources01">IETF RFC2119 Requirement Levels: <a href="http://www.ietf.org/rfc/rfc2119.txt">http://www.ietf.org/rfc/rfc2119.txt</a></li> 207 <a name="resources02"></a><li id="resources02">Android Compatibility Program Overview: <a href="http://source.android.com/compatibility/index.html">http://source.android.com/compatibility/index.html</a></li> 208 <a name="resources03"></a><li id="resources03">Android Open Source Project: <a href="http://source.android.com/">http://source.android.com/</a></li> 209 <a name="resources04"></a><li id="resources04">API definitions and documentation: <a href="http://developer.android.com/reference/packages.html">http://developer.android.com/reference/packages.html</a></li> 210 <a name="resources05"></a><li id="resources05">Android Permissions reference: <a href="http://developer.android.com/reference/android/Manifest.permission.html">http://developer.android.com/reference/android/Manifest.permission.html</a></li> 211 <a name="resources06"></a><li id="resources06">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></li> 212 <a name="resources07"></a><li id="resources07">Android 4.4 allowed version strings: <a href="http://source.android.com/compatibility/4.4/versions.html">http://source.android.com/compatibility/4.4/versions.html</a></li> 213 <a name="resources08"></a><li id="resources08">Renderscript: <a href="http://developer.android.com/guide/topics/graphics/renderscript.html">http://developer.android.com/guide/topics/graphics/renderscript.html</a></li> 214 <a name="resources09"></a><li id="resources09">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></li> 215 <a name="resources10"></a><li id="resources10">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></li> 216 <a name="resources11"></a><li id="resources11">HTML5: <a href="http://www.whatwg.org/specs/web-apps/current-work/multipage/">http://www.whatwg.org/specs/web-apps/current-work/multipage/</a></li> 217 <a name="resources12"></a><li id="resources12">HTML5 offline capabilities: <a href="http://dev.w3.org/html5/spec/Overview.html#offline">http://dev.w3.org/html5/spec/Overview.html#offline</a></li> 218 <a name="resources13"></a><li id="resources13">HTML5 video tag: <a href="http://dev.w3.org/html5/spec/Overview.html#video">http://dev.w3.org/html5/spec/Overview.html#video</a></li> 219 <a name="resources14"></a><li id="resources14">HTML5/W3C geolocation API: <a href="http://www.w3.org/TR/geolocation-API/">http://www.w3.org/TR/geolocation-API/</a></li> 220 <a name="resources15"></a><li id="resources15">HTML5/W3C webstorage API: <a href="http://www.w3.org/TR/webstorage/">http://www.w3.org/TR/webstorage/</a></li> 221 <a name="resources16"></a><li id="resources16">HTML5/W3C IndexedDB API: <a href="http://www.w3.org/TR/IndexedDB/">http://www.w3.org/TR/IndexedDB/</a></li> 222 <a name="resources17"></a><li id="resources17">Dalvik Virtual Machine specification: available in the Android source code, at dalvik/docs</li> 223 <a name="resources18"></a><li id="resources18">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></li> 224 <a name="resources19"></a><li id="resources19">Notifications: <a href="http://developer.android.com/guide/topics/ui/notifiers/notifications.html">http://developer.android.com/guide/topics/ui/notifiers/notifications.html</a></li> 225 <a name="resources20"></a><li id="resources20">Application Resources: <a href="http://code.google.com/android/reference/available-resources.html">http://code.google.com/android/reference/available-resources.html</a></li> 226 <a name="resources21"></a><li id="resources21">Status Bar icon style guide: <a href="http://developer.android.com/guide/practices/ui_guidelines/icon_design_status_bar.html">http://developer.android.com/guide/practices/ui_guidelines/icon_design_status_bar.html</a></li> 227 <a name="resources22"></a><li id="resources22">Search Manager: <a href="http://developer.android.com/reference/android/app/SearchManager.html">http://developer.android.com/reference/android/app/SearchManager.html</a></li> 228 <a name="resources23"></a><li id="resources23">Toasts: <a href="http://developer.android.com/reference/android/widget/Toast.html">http://developer.android.com/reference/android/widget/Toast.html</a></li> 229 <a name="resources24"></a><li id="resources24">Themes: <a href="http://developer.android.com/guide/topics/ui/themes.html">http://developer.android.com/guide/topics/ui/themes.html</a></li> 230 <a name="resources25"></a><li id="resources25">R.style class: <a href="http://developer.android.com/reference/android/R.style.html">http://developer.android.com/reference/android/R.style.html</a></li> 231 <a name="resources26"></a><li id="resources26">Live Wallpapers: <a href="http://developer.android.com/resources/articles/live-wallpapers.html">http://developer.android.com/resources/articles/live-wallpapers.html</a></li> 232 <a name="resources27"></a><li id="resources27">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></li> 233 <a name="resources28"></a><li id="resources28">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></li> 234 <a name="resources29"></a><li id="resources29">Android Accessibility Service APIs: <a href="http://developer.android.com/reference/android/accessibilityservice/package-summary.html">http://developer.android.com/reference/android/accessibilityservice/package-summary.html</a></li> 235 <a name="resources30"></a><li id="resources30">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></li> 236 <a name="resources31"></a><li id="resources31">Eyes Free project: <a href="http://http://code.google.com/p/eyes-free">http://code.google.com/p/eyes-free</a></li> 237 <a name="resources32"></a><li id="resources32">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></li> 238 <a name="resources33"></a><li id="resources33">Reference tool documentation (for adb, aapt, ddms, systrace): <a href="http://developer.android.com/guide/developing/tools/index.html">http://developer.android.com/guide/developing/tools/index.html</a></li> 239 <a name="resources34"></a><li id="resources34">Android apk file description: <a href="http://developer.android.com/guide/topics/fundamentals.html">http://developer.android.com/guide/topics/fundamentals.html</a></li> 240 <a name="resources35"></a><li id="resources35">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></li> 241 <a name="resources36"></a><li id="resources36">Monkey testing tool: <a href="http://developer.android.com/guide/developing/tools/monkey.html">http://developer.android.com/guide/developing/tools/monkey.html</a></li> 242 <a name="resources37"></a><li id="resources37">Android android.content.pm.PackageManager class and Hardware Features List: <a href="http://developer.android.com/reference/android/content/pm/PackageManager.html">http://developer.android.com/reference/android/content/pm/PackageManager.html</a></li> 243 <a name="resources38"></a><li id="resources38">Supporting Multiple Screens: <a href="http://developer.android.com/guide/practices/screens_support.html">http://developer.android.com/guide/practices/screens_support.html</a></li> 244 <a name="resources39"></a><li id="resources39">android.util.DisplayMetrics: <a href="http://developer.android.com/reference/android/util/DisplayMetrics.html">http://developer.android.com/reference/android/util/DisplayMetrics.html</a></li> 245 <a name="resources40"></a><li id="resources40">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></li> 246 <a name="resources41"></a><li id="resources41">android.hardware.SensorEvent: <a href="http://developer.android.com/reference/android/hardware/SensorEvent.html">http://developer.android.com/reference/android/hardware/SensorEvent.html</a></li> 247 <a name="resources42"></a><li id="resources42">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></li> 248 <a name="resources43"></a><li id="resources43">NDEF Push Protocol: <a href="http://source.android.com/compatibility/ndef-push-protocol.pdf">http://source.android.com/compatibility/ndef-push-protocol.pdf</a></li> 249 <a name="resources44"></a><li id="resources44">MIFARE MF1S503X: <a href="http://www.nxp.com/documents/data_sheet/MF1S503x.pdf">http://www.nxp.com/documents/data_sheet/MF1S503x.pdf</a></li> 250 <a name="resources45"></a><li id="resources45">MIFARE MF1S703X: <a href="http://www.nxp.com/documents/data_sheet/MF1S703x.pdf">http://www.nxp.com/documents/data_sheet/MF1S703x.pdf</a></li> 251 <a name="resources46"></a><li id="resources46">MIFARE MF0ICU1: <a href="http://www.nxp.com/documents/data_sheet/MF0ICU1.pdf">http://www.nxp.com/documents/data_sheet/MF0ICU1.pdf</a></li> 252 <a name="resources47"></a><li id="resources47">MIFARE MF0ICU2: <a href="http://www.nxp.com/documents/short_data_sheet/MF0ICU2_SDS.pdf">http://www.nxp.com/documents/short_data_sheet/MF0ICU2_SDS.pdf</a></li> 253 <a name="resources48"></a><li id="resources48">MIFARE AN130511: <a href="http://www.nxp.com/documents/application_note/AN130511.pdf">http://www.nxp.com/documents/application_note/AN130511.pdf</a></li> 254 <a name="resources49"></a><li id="resources49">MIFARE AN130411: <a href="http://www.nxp.com/documents/application_note/AN130411.pdf">http://www.nxp.com/documents/application_note/AN130411.pdf</a></li> 255 <a name="resources50"></a><li id="resources50">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></li> 256 <a name="resources51"></a><li id="resources51">Camera: <a href="http://developer.android.com/reference/android/hardware/Camera.html">http://developer.android.com/reference/android/hardware/Camera.html</a></li> 257 <a name="resources52"></a><li id="resources52">Android Open Accessories: <a href="http://developer.android.com/guide/topics/usb/accessory.html">http://developer.android.com/guide/topics/usb/accessory.html</a></li> 258 <a name="resources53"></a><li id="resources53">USB Host API: <a href="http://developer.android.com/guide/topics/usb/host.html">http://developer.android.com/guide/topics/usb/host.html</a></li> 259 <a name="resources54"></a><li id="resources54">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></li> 260 <a name="resources55"></a><li id="resources55">Apps for Android: <a href="http://code.google.com/p/apps-for-android">http://code.google.com/p/apps-for-android</a></li> 261 <a name="resources56"></a><li id="resources56">Android DownloadManager: <a href="http://developer.android.com/reference/android/app/DownloadManager.html">http://developer.android.com/reference/android/app/DownloadManager.html</a></li> 262 <a name="resources57"></a><li id="resources57">Android File Transfer: <a href="http://www.android.com/filetransfer">http://www.android.com/filetransfer</a></li> 263 <a name="resources58"></a><li id="resources58">Android Media Formats: <a href="http://developer.android.com/guide/appendix/media-formats.html">http://developer.android.com/guide/appendix/media-formats.html</a></li> 264 <a name="resources59"></a><li id="resources59">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></li> 265 <a name="resources60"></a><li id="resources60">NFC Connection Handover: <a href="http://www.nfc-forum.org/specs/spec_list/#conn_handover/">http://www.nfc-forum.org/specs/spec_list/#conn_handover</a></li> 266 <a name="resources61"></a><li id="resources61">Bluetooth Secure Simple Pairing Using NFC: <a href="http://www.nfc-forum.org/resources/AppDocs/NFCForum_AD_BTSSP_1_0.pdf">http://www.nfc-forum.org/resources/AppDocs/NFCForum_AD_BTSSP_1_0.pdf</a></li> 267 <a name="resources62"></a> 268 <li id="resources62">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></li> 269 <a name="resources63"></a><li id="resources63">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></li> 270 <a name="resources64"></a><li id="resources64">USB Charging Specification: <a href="http://www.usb.org/developers/devclass_docs/USB_Battery_Charging_1.2.pdf">http://www.usb.org/developers/devclass_docs/USB_Battery_Charging_1.2.pdf</a></li> 271 <a name="resources65"></a><li id="resources65">Android Beam: <a href="http://developer.android.com/guide/topics/nfc/nfc.html">http://developer.android.com/guide/topics/nfc/nfc.html</a></li> 272 <a name="resources66"></a><li id="resources66">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></li> 273 <a name="resources67"></a><li id="resources67">Android NFC Sharing Settings: <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></li> 274 <a name="resources68"></a> 275 <li id="resources68">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></li> 276 <a name="resources69"></a><li id="resources69">Lock and Home Screen Widget: <a href="http://developer.android.com/reference/android/appwidget/AppWidgetProviderInfo.html">http://developer.android.com/reference/android/appwidget/AppWidgetProviderInfo.html</a></li> 277 <a name="resources70"></a><li id="resources70">UserManager reference: <a href="http://developer.android.com/reference/android/os/UserManager.html">http://developer.android.com/reference/android/os/UserManager.html</a></li> 278 <a name="resources71"></a><li id="resources71">External Storage reference: <a 279 href="http://source.android.com/devices/tech/storage">http://source.android.com/devices/tech/storage</a></li> 280 <a name="resources72"></a><li id="resources72">External Storage APIs: <a href="http://developer.android.com/reference/android/os/Environment.html">http://developer.android.com/reference/android/os/Environment.html</a></li> 281 <a name="resources73"></a><li id="resources73">SMS Short Code: <a href="http://en.wikipedia.org/wiki/Short_code">http://en.wikipedia.org/wiki/Short_code</a></li> 282 <a name="resources74"></a><li id="resources74">Media Remote Control Client: <a href="http://developer.android.com/reference/android/media/RemoteControlClient.html">http://developer.android.com/reference/android/media/RemoteControlClient.html</a></li> 283 <a name="resources75"></a><li id="resources75">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></li> 284 <a name="resources76"></a><li id="resources76">Dreams: <a href="http://developer.android.com/reference/android/service/dreams/DreamService.html">http://developer.android.com/reference/android/service/dreams/DreamService.html</a></li> 285 <a name="resources77"></a><li id="resources77">Android Application Development-Related Settings: <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></li> 286 <a name="resources78"></a><li id="resources78">Camera: <a href="http://developer.android.com/reference/android/hardware/Camera.Parameters.html">http://developer.android.com/reference/android/hardware/Camera.Parameters.html</a></li> 287 <a name="resources79"></a><li id="resources79">EGL Extension-EGL_ANDROID_RECORDABLE: <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></li> 288 <a name="resources80"></a><li id="resources80">Motion Event API: <a href="http://developer.android.com/reference/android/view/MotionEvent.html">http://developer.android.com/reference/android/view/MotionEvent.html</a></li> 289 <a name="resources81"></a><li id="resources81">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></li> 290 <a name="resources82"></a><li id="resources82">Unicode 6.1.0: <a href="http://www.unicode.org/versions/Unicode6.1.0/">http://www.unicode.org/versions/Unicode6.1.0/</a></li> 291 <a name="resources83"></a><li id="resources83">WebView compatibility: <a href="http://www.chromium.org/">http://www.chromium.org/</a></li> 292 <a name="resources84"></a><li id="resources84">Android Device Owner App: <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></li> 293 <a name="resources85"></a><li id="resources85">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></li> 294 <a name="resources86"></a><li id="resources86">RTC Hardware Coding Requirements: <a href="http://www.webmproject.org/hardware/rtc-coding-requirements/">http://www.webmproject.org/hardware/rtc-coding-requirements/</a></li> 295 <a name="resources87"></a><li id="resources87">Settings.Secure LOCATION_MODE: <a 296 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></li> 297 <a name="resources88"></a><li id="resources88">Content Resolver: <a href="http://developer.android.com/reference/android/content/ContentResolver.html">http://developer.android.com/reference/android/content/ContentResolver.html</a></li> 298 <a name="resources89"></a><li id="resources89">SettingInjectorService: <a 299 href="http://developer.android.com/reference/android/location/SettingInjectorService.html">http://developer.android.com/reference/android/location/SettingInjectorService.html</a></li> 300 <a name="resources90"></a><li id="resources90">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></li> 301 <a name="resources91"></a><li id="resources91">Telephony Provider: <a href="http://developer.android.com/reference/android/provider/Telephony.html">http://developer.android.com/reference/android/provider/Telephony.html</a></li> 302 </ol> 303 <p>Many of these resources are derived directly or indirectly from the Android 304 SDK, and will be functionally identical to the information in that SDK's 305 documentation. In any cases where this Compatibility Definition or the 306 Compatibility Test Suite disagrees with the SDK documentation, the SDK 307 documentation is considered authoritative. Any technical details provided in 308 the references included above are considered by inclusion to be part of this 309 Compatibility Definition.</p> 310 311 <a name="section-3"></a><h2 id="section-3">3. Software</h2> 312 <a name="section-3.1"></a><h3 id="section-3.1">3.1. Managed API Compatibility</h3> 313 <p>The managed (Dalvik-based) execution environment is the primary vehicle for 314 Android applications. The Android application programming interface (API) is 315 the set of Android platform interfaces exposed to applications running in the 316 managed VM environment. Device implementations MUST provide complete 317 implementations, including all documented behaviors, of any documented API 318 exposed by the Android SDK [<a href="#resources04">Resources, 4</a>].</p> 319 <p>Device implementations MUST NOT omit any managed APIs, alter API interfaces 320 or signatures, deviate from the documented behavior, or include no-ops, except 321 where specifically allowed by this Compatibility Definition.</p> 322 <p>This Compatibility Definition permits some types of hardware for which 323 Android includes APIs to be omitted by device implementations. In such cases, 324 the APIs MUST still be present and behave in a reasonable way. See 325 <a href="#section-7">Section 7</a> for specific requirements for this scenario. 326 </p> 327 328 <a name="section-3.2"></a><h3 id="section-3.2">3.2. Soft API Compatibility</h3> 329 <p>In addition to the managed APIs from Section 3.1, Android also includes a 330 significant runtime-only "soft" API, in the form of such things such as 331 Intents, permissions, and similar aspects of Android applications that cannot 332 be enforced at application compile time.</p> 333 <a name="section-3.2.1"></a><h4 id="section-3.2.1">3.2.1. Permissions</h4> 334 <p>Device implementers MUST support and enforce all permission constants as 335 documented by the Permission reference page [<a 336 href="#resources05">Resources, 5</a>]. Note that Section 9 lists additional 337 requirements related to the Android security model.</p> 338 <a name="section-3.2.2"></a><h4 id="section-3.2.2">3.2.2. Build Parameters</h4> 339 <p>The Android APIs include a number of constants on the <code>android.os.Build</code> 340 class [<a href="#resources06">Resources, 6</a>] that are intended to describe 341 the current device. To provide consistent, meaningful values across device 342 implementations, the table below includes additional restrictions on the 343 formats of these values to which device implementations MUST conform.</p> 344 <table> 345 <tbody> 346 <tr> 347 <td><b>Parameter</b></td> 348 <td><b>Comments</b></td> 349 </tr> 350 <tr> 351 <td>VERSION.RELEASE</td> 352 <td>The version of the currently-executing Android system, in human-readable 353 format. This field MUST have one of the string values defined in [<a 354 href="#resources07">Resources, 7</a>].</td> 355 </tr> 356 <tr> 357 <td>VERSION.SDK</td> 358 <td>The version of the currently-executing Android system, in a format 359 accessible to third-party application code. For Android 4.4, this 360 field MUST have the integer value 19.</td> 361 </tr> 362 <tr> 363 <td>VERSION.SDK_INT</td> 364 <td>The version of the currently-executing Android system, in a format 365 accessible to third-party application code. For Android 4.4, this 366 field MUST have the integer value 19.</td> 367 </tr> 368 <tr> 369 <td>VERSION.INCREMENTAL</td> 370 <td>A value chosen by the device implementer designating the specific build of 371 the currently-executing Android system, in human-readable format. This value 372 MUST NOT be re-used for different builds made available to end users. A typical use 373 of this field is to indicate which build number or source-control change 374 identifier was used to generate the build. There are no requirements on the 375 specific format of this field, except that it MUST NOT be null or the empty 376 string ("").</td> 377 </tr> 378 <tr> 379 <td>BOARD</td> 380 <td>A value chosen by the device implementer identifying the specific internal 381 hardware used by the device, in human-readable format. A possible use of this 382 field is to indicate the specific revision of the board powering the device. 383 The value of this field MUST be encodable as 7-bit ASCII and match the regular expression 384 <code>"^[a-zA-Z0-9.,_-]+$"</code>.</td> 385 </tr> 386 <tr> 387 <td>BRAND</td> 388 <td>A value reflecting the brand name associated with the device as 389 known to the end users. MUST be in human-readable format and SHOULD represent 390 the manufacturer of the device or the company brand under which the device is 391 marketed. The value of this field MUST be encodable as 7-bit ASCII and match the 392 regular expression <code>"^[a-zA-Z0-9.,_-]+$"</code>. 393 </td> 394 </tr> 395 <tr> 396 <td>CPU_ABI</td> 397 <td>The name of the instruction set (CPU type + ABI convention) of native code. 398 See <a href="#section-3.3">Section 3.3: Native API Compatibility</a>. 399 </td> 400 </tr> 401 <tr> 402 <td>CPU_ABI2</td> 403 <td>The name of the second instruction set (CPU type + ABI convention) of native code. 404 See <a href="#section-3.3">Section 3.3: Native API Compatibility</a>. 405 </td> 406 </tr> 407 <tr> 408 <td>DEVICE</td> 409 <td>A value chosen by the device implementer containing the development name or 410 code name identifying the configuration of the hardware features and industrial 411 design of the device. The value of this field MUST be encodable as 7-bit ASCII 412 and match the regular expression <code>"^[a-zA-Z0-9.,_-]+$"</code>. 413 </td> 414 </tr> 415 <tr> 416 <td>FINGERPRINT</td> 417 <td>A string that uniquely identifies this build. It SHOULD be reasonably 418 human-readable. It MUST follow this template: 419 <br/><code>$(BRAND)/$(PRODUCT)/$(DEVICE):$(VERSION.RELEASE)/$(ID)/$(VERSION.INCREMENTAL):$(TYPE)/$(TAGS)</code><br/> 420 For example: 421 <br/><code>acme/myproduct/mydevice:4.4/KRT16/3359:userdebug/test-keys</code><br/> 422 The fingerprint MUST NOT include whitespace characters. If other fields included in the 423 template above have whitespace characters, they MUST be replaced in the build 424 fingerprint with another character, such as the underscore ("_") character. 425 The value of this field MUST be encodable as 7-bit ASCII.</td> 426 </tr> 427 <tr> 428 <td>HARDWARE</td> 429 <td>The name of the hardware (from the kernel command line or /proc). It SHOULD be 430 reasonably human-readable. The value of this field MUST be encodable as 7-bit ASCII and 431 match the regular expression <code>"^[a-zA-Z0-9.,_-]+$"</code>.</td> 432 </tr> 433 <tr> 434 <td>HOST</td> 435 <td>A string that uniquely identifies the host the build was built on, in 436 human readable format. There are no requirements on the specific format of 437 this field, except that it MUST NOT be null or the empty string ("").</td> 438 </tr> 439 <tr> 440 <td>ID</td> 441 <td>An identifier chosen by the device implementer to refer to a specific 442 release, in human readable format. This field can be the same as 443 android.os.Build.VERSION.INCREMENTAL, but SHOULD be a value sufficiently 444 meaningful for end users to distinguish between software builds. The value of 445 this field MUST be encodable as 7-bit ASCII and match the regular expression 446 <code>"^[a-zA-Z0-9.,_-]+$"</code>. 447 </td> 448 </tr> 449 <tr> 450 <td>MANUFACTURER</td> 451 <td>The trade name of the Original Equipment Manufacturer (OEM) of the product. 452 There are no requirements on the specific format of this field, except that it 453 MUST NOT be null or the empty string ("").</td> 454 </tr> 455 <tr> 456 <td>MODEL</td> 457 <td>A value chosen by the device implementer containing the name of the device 458 as known to the end user. This SHOULD be the same name under which the device 459 is marketed and sold to end users. There are no requirements on the specific 460 format of this field, except that it MUST NOT be null or the empty string 461 ("").</td> 462 </tr> 463 <tr> 464 <td>PRODUCT</td> 465 <td>A value chosen by the device implementer containing the development name or 466 code name of the specific product (SKU) that SHOULD be unique within the same 467 brand. MUST be human-readable, but is not necessarily intended for view by end 468 users. The value of this field MUST be encodable as 7-bit ASCII and match the 469 regular expression <code>"^[a-zA-Z0-9.,_-]+$"</code>. 470 </td> 471 </tr> 472 <tr> 473 <td>SERIAL</td> 474 <td>A hardware serial number, which MUST be available. The value of this field MUST be encodable 475 as 7-bit ASCII and match the regular expression 476 <code>"^([a-zA-Z0-9]{6,20})$"</code>.</td> 477 </tr> 478 <tr> 479 <td>TAGS</td> 480 <td>A comma-separated list of tags chosen by the device implementer that 481 further distinguishes the build. For example, "unsigned,debug". The value of 482 this field MUST be encodable as 7-bit ASCII and match the regular expression 483 <code>"^[a-zA-Z0-9.,_-]+$"</code>.</td> 484 </tr> 485 <tr> 486 <td>TIME</td> 487 <td>A value representing the timestamp of when the build occurred.</td> 488 </tr> 489 <tr> 490 <td>TYPE</td> 491 <td>A value chosen by the device implementer specifying the runtime 492 configuration of the build. This field SHOULD have one of the values 493 corresponding to the three typical Android runtime configurations: "user", 494 "userdebug", or "eng". The value of this field MUST be 495 encodable as 7-bit ASCII and match the regular expression 496 <code>"^[a-zA-Z0-9.,_-]+$"</code>.</td> 497 </tr> 498 <tr> 499 <td>USER</td> 500 <td>A name or user ID of the user (or automated user) that generated the 501 build. There are no requirements on the specific format of this field, except 502 that it MUST NOT be null or the empty string ("").</td> 503 </tr> 504 </tbody> 505 </table> 506 <a name="section-3.2.3"></a><h4 id="section-3.2.3">3.2.3. Intent Compatibility</h4> 507 <p> 508 Device implementations MUST honor Android's loose-coupling Intent system, as 509 described in the sections below. By "honored", it is meant that the device 510 implementer MUST provide an Android Activity or Service that specifies a 511 matching Intent filter and binds to and implements correct behavior for each 512 specified Intent pattern.</p> 513 <a name="section-3.2.3.1"></a><h4 id="section-3.2.3.1">3.2.3.1. Core Application Intents</h4> 514 <p>The Android upstream project defines a number of core applications, such as 515 contacts, calendar, photo gallery, music player, and so on. Device implementers 516 MAY replace these applications with alternative versions.</p> 517 <p>However, any such alternative versions MUST honor the same Intent patterns 518 provided by the upstream project. For example, if a device contains an 519 alternative music player, it must still honor the Intent pattern issued by 520 third-party applications to pick a song.</p> 521 <p>The following applications are considered core Android system 522 applications:</p> 523 <ul> 524 <li>Desk Clock</li> 525 <li>Browser</li> 526 <li>Calendar</li> 527 <li>Contacts</li> 528 <!--<li>Email</li>--> 529 <li>Gallery</li> 530 <li>GlobalSearch</li> 531 <li>Launcher</li> 532 <!-- <li>LivePicker (that is, the Live Wallpaper picker application; MAY be omitted 533 if the device does not support Live Wallpapers, per Section 3.8.5.)</li> --> 534 <!-- <li>Messaging (AKA "Mms")</li> --> 535 <li>Music</li> 536 <!-- <li>Phone</li> --> 537 <li>Settings</li> 538 <!-- <li>SoundRecorder</li> --> 539 </ul> 540 <p>The core Android system applications include various Activity, or Service 541 components that are considered "public". That is, the attribute 542 "android:exported" may be absent, or may have the value "true".</p> 543 <p>For every Activity or Service defined 544 in one of the core Android system apps that is not marked as non-public via an 545 android:exported attribute with the value "false", device implementations MUST 546 include a component of the same type implementing the same Intent filter 547 patterns as the core Android system app.</p> 548 <p>In other words, a device implementation MAY replace core Android system 549 apps; however, if it does, the device implementation MUST support all Intent 550 patterns defined by each core Android system app being replaced.</p> 551 <a name="section-3.2.3.2"></a><h4 id="section-3.2.3.2">3.2.3.2. Intent Overrides</h4> 552 <p>As Android is an extensible platform, device implementations MUST allow each 553 Intent pattern referenced in Section 3.2.3.1 to be overridden by third-party 554 applications. The upstream Android open source implementation allows this by 555 default; device implementers MUST NOT attach special privileges to system 556 applications' use of these Intent patterns, or prevent third-party 557 applications from binding to and assuming control of these patterns. This 558 prohibition specifically includes but is not limited to disabling the 559 "Chooser" user interface that allows the user to select between multiple 560 applications which all handle the same Intent pattern.</p> 561 <p>However, device implementations MAY provide default activities for specific 562 URI patterns (eg. http://play.google.com) if the default activity provides a 563 more specific filter for the data URI. For example, an intent filter specifying 564 the data URI "http://www.android.com" is more specific than the browser filter 565 for "http://". Device implementations MUST provide a user interface for users 566 to modify the default activity for intents.</p> 567 568 <a name="section-3.2.3.3"></a><h4 id="section-3.2.3.3">3.2.3.3. Intent Namespaces</h4> 569 <p>Device implementations MUST NOT include any Android component that honors any 570 new Intent or Broadcast Intent patterns using an ACTION, CATEGORY, or other 571 key string in the android.* or com.android.* namespace. Device implementers 572 MUST NOT include any Android components that honor any new Intent or Broadcast 573 Intent patterns using an ACTION, CATEGORY, or other key string in a package 574 space belonging to another organization. Device implementers MUST NOT alter or 575 extend any of the Intent patterns used by the core apps listed in Section 576 3.2.3.1. Device implementations MAY include Intent patterns using 577 namespaces clearly and obviously associated with their own organization.</p> 578 <p>This prohibition is analogous to that specified for Java language classes 579 in Section 3.6.</p> 580 581 <a name="section-3.2.3.4"></a><h4 id="section-3.2.3.4">3.2.3.4. Broadcast Intents</h4> 582 <p>Third-party applications rely on the platform to broadcast certain Intents 583 to notify them of changes in the hardware or software environment. 584 Android-compatible devices MUST broadcast the public broadcast Intents in 585 response to appropriate system events. Broadcast Intents are described in the 586 SDK documentation.</p> 587 588 <a name="section-3.2.3.5"></a><h4 id="section-3.2.3.5">3.2.3.5. Default App Settings</h4> 589 <p>Android 4.4 adds settings that allow users to select their default Home and 590 SMS applications. Device implementations MUST provide a similar user settings 591 menu for each, compatible with the Intent filter pattern and API methods 592 described in the SDK documentation [<a href="#resources91">Resources, 91</a>]. 593 </p> 594 595 <a name="section-3.3"></a><h3 id="section-3.3">3.3. Native API Compatibility</h3> 596 <a name="section-3.3.1"></a><h4 id="section-3.3.1">3.3.1 Application Binary Interfaces</h4> 597 <p>Managed code running in Dalvik can call into native code provided in the 598 application .apk file as an ELF .so file compiled for the appropriate device 599 hardware architecture. As native code is highly dependent on the underlying 600 processor technology, Android defines a number of Application Binary 601 Interfaces (ABIs) in the Android NDK, in the file 602 <code>docs/CPU-ARCH-ABIS.html</code>. If a device implementation is compatible 603 with one or more defined ABIs, it SHOULD implement compatibility with the 604 Android NDK, as below.</p> 605 <p>If a device implementation includes support for an Android ABI, it:</p> 606 <ul> 607 <li>MUST include support for code running in the managed environment to call 608 into native code, using the standard Java Native Interface (JNI) 609 semantics</li> 610 <li>MUST be source-compatible (i.e. header compatible) and binary-compatible 611 (for the ABI) with each required library in the list below</li> 612 <li>MUST accurately report the native Application Binary Interface (ABI) 613 supported by the device, via the <code>android.os.Build.CPU_ABI</code> 614 API and <code>android.os.Build.CPU_ABI2</code> parameters.</li> 615 <li>MUST report, via <code>android.os.Build.CPU_ABI2</code>, only those ABIs 616 documented in the latest version of the Android NDK, in the file 617 <code>docs/CPU-ARCH-ABIS.html</code></li> 618 <li>MUST report, via <code>android.os.Build.CPU_ABI</code>, only one of the 619 ABIs listed below</li> 620 <ul> 621 <li>armeabi-v7a</li> 622 <li>x86</li> 623 <li>mips</li> 624 </ul> 625 <li>SHOULD be built using the source code and header files available in the 626 upstream Android Open Source Project</li> 627 </ul> 628 <p>The following native code APIs MUST be available to apps that include 629 native code:</p> 630 <ul> 631 <li>libc (C library)</li> 632 <li>libm (math library)</li> 633 <li>Minimal support for C++</li> 634 <li>JNI interface</li> 635 <li>liblog (Android logging)</li> 636 <li>libz (Zlib compression)</li> 637 <li>libdl (dynamic linker)</li> 638 <li>libGLESv1_CM.so (OpenGL ES 1.0)</li> 639 <li>libGLESv2.so (OpenGL ES 2.0)</li> 640 <li>libGLESv3.so (OpenGL ES 3.0)</li> 641 <li>libEGL.so (native OpenGL surface management)</li> 642 <li>libjnigraphics.so</li> 643 <li>libOpenSLES.so (OpenSL ES 1.0.1 audio support)</li> 644 <li>libOpenMAXAL.so (OpenMAX AL 1.0.1 support)</li> 645 <li>libandroid.so (native Android activity support)</li> 646 <li>Support for OpenGL, as described below</li> 647 </ul> 648 <p>Note that future releases of the Android NDK may introduce support for 649 additional ABIs. If a device implementation is not compatible with an existing 650 predefined ABI, it MUST NOT report support for any ABI at all.</p> 651 <p>Note that device implementations MUST include libGLESv3.so and it MUST symlink (symbolic) 652 link to libGLESv2.so. On device implementations that declare support for OpenGL ES 3.0, libGLESv2.so 653 MUST export the OpenGL ES 3.0 function symbols in addition to the OpenGL ES 2.0 function symbols.</p> 654 <p>Native code compatibility is challenging. For this reason, it should be 655 repeated that device implementers are VERY strongly encouraged to use the 656 upstream implementations of the libraries listed above to help ensure 657 compatibility.</p> 658 659 <a name="section-3.4"></a><h3 id="section-3.4">3.4. Web Compatibility</h3> 660 <a name="section-3.4.1"></a><h4 id="section-3.4.1">3.4.1. WebView Compatibility</h4> 661 <p>The Android Open Source implementation uses code from the Chromium 662 Project to implement the <code>android.webkit.WebView</code> [<a href="#resources10">Resources, 10</a>] . Because it is not feasible 663 to develop a comprehensive test suite for a web rendering system, device 664 implementers MUST use the specific upstream build of Chromium in the WebView 665 implementation. Specifically:</p> 666 <ul> 667 <li>Device <code>android.webkit.WebView</code> implementations MUST be based 668 on the Chromium build from the upstream Android Open Source Project for Android 4.4. 669 This build includes a specific set of functionality and security fixes for the 670 WebView. [<a href="#resources83">Resources, 83</a>]</li> 671 <li>The user agent string reported by the WebView MUST be in this format:<br/> 672 <code>Mozilla/5.0 (Linux; Android $(VERSION); $(LOCALE); $(MODEL) 673 Build/$(BUILD)) AppleWebKit/537.36 (KHTML, like Gecko) Version/4.0 674 $(CHROMIUM_VER) Mobile Safari/537.36</code> 675 <ul> 676 <li>The value of the $(VERSION) string MUST be the same as the value for 677 <code>android.os.Build.VERSION.RELEASE</code>.</li> 678 <li>The value of the $(LOCALE) string is optional, SHOULD follow the ISO 679 conventions for country code and language, and SHOULD refer to the current 680 configured locale of the device. If omitted, the trailing semicolon MUST 681 also be removed.</li> 682 <li>The value of the $(MODEL) string MUST be the same as the value for 683 <code>android.os.Build.MODEL</code>.</li> 684 <li>The value of the $(BUILD) string MUST be the same as the value for 685 <code>android.os.Build.ID</code>.</li> 686 <li>The value of the $(CHROMIUM_VER) string MUST be the version of Chromium in 687 the upstream Android Open Source Project.</li> 688 <li>Device implementations MAY omit <code>Mobile</code> in the user agent 689 string.</li> 690 </ul> 691 </li> 692 </ul> 693 <p>The WebView component SHOULD include support for as much of HTML5 [<a 694 href="#resources11">Resources, 11</a>] as possible.</p> 695 <a name="section-3.4.2"></a><h4 id="section-3.4.2">3.4.2. Browser Compatibility</h4> 696 <p>Device implementations MUST include a standalone Browser application for 697 general user web browsing. The standalone Browser MAY be based on a 698 browser technology other than WebKit. However, even if an alternate Browser 699 application is used, the <code>android.webkit.WebView</code> component 700 provided to third-party applications MUST be based on WebKit, as described in 701 Section 3.4.1.</p> 702 <p>Implementations MAY ship a custom user agent string in the standalone 703 Browser application.</p> 704 <p>The standalone Browser application (whether based on the upstream 705 WebKit Browser application or a third-party replacement) SHOULD include support 706 for as much of HTML5 [<a href="#resources11">Resources, 11</a>] as possible. 707 Minimally, device implementations MUST support each of these APIs associated 708 with HTML5:</p> 709 <ul> 710 <li>application cache/offline operation [<a href="#resources12">Resources, 12</a>]</li> 711 <li>the <video> tag [<a href="#resources13">Resources, 13</a>]</li> 712 <li>geolocation [<a href="#resources14">Resources, 14</a>]</li> 713 </ul> 714 <p>Additionally, device implementations MUST support the HTML5/W3C webstorage 715 API [<a href="#resources15">Resources, 15</a>], and SHOULD support the 716 HTML5/W3C IndexedDB API [<a href="#resources16">Resources, 16</a>]. <i>Note 717 that as the web development standards bodies are transitioning to favor 718 IndexedDB over webstorage, IndexedDB is expected to become a required 719 component in a future version of Android.</i></p> 720 721 <a name="section-3.5"></a><h3 id="section-3.5">3.5. API Behavioral Compatibility</h3> 722 <p>The behaviors of each of the API types (managed, soft, native, and web) 723 must be consistent with the preferred implementation of the upstream Android 724 Open Source Project [<a href="#resources03">Resources, 3</a>]. Some specific areas 725 of compatibility are:</p> 726 <ul> 727 <li>Devices MUST NOT change the behavior or semantics of a standard Intent</li> 728 <li>Devices MUST NOT alter the lifecycle or lifecycle semantics of a 729 particular type of system component (such as Service, Activity, 730 ContentProvider, etc.)</li> 731 <li>Devices MUST NOT change the semantics of a standard permission</li> 732 </ul> 733 <p>The above list is not comprehensive. The Compatibility Test Suite (CTS) 734 tests significant portions of the platform for behavioral compatibility, but 735 not all. It is the responsibility of the implementer to ensure behavioral 736 compatibility with the Android Open Source Project. For this reason, device 737 implementers SHOULD use the source code available via the Android Open Source 738 Project where possible, rather than re-implement significant parts of the 739 system.</p> 740 741 742 <a name="section-3.6"></a><h3 id="section-3.6">3.6. API Namespaces</h3> 743 <p>Android follows the package and class namespace conventions defined by the 744 Java programming language. To ensure compatibility with third-party 745 applications, device implementers MUST NOT make any prohibited modifications 746 (see below) to these package namespaces:</p> 747 <ul> 748 <li>java.*</li> 749 <li>javax.*</li> 750 <li>sun.*</li> 751 <li>android.*</li> 752 <li>com.android.*</li> 753 </ul> 754 <p>Prohibited modifications include:</p> 755 <ul> 756 <li>Device implementations MUST NOT modify the publicly exposed APIs on the 757 Android platform by changing any method or class signatures, or by removing 758 classes or class fields.</li> 759 <li>Device implementers MAY modify the underlying implementation of the APIs, 760 but such modifications MUST NOT impact the stated behavior and Java-language 761 signature of any publicly exposed APIs.</li> 762 <li>Device implementers MUST NOT add any publicly exposed elements (such as 763 classes or interfaces, or fields or methods to existing classes or interfaces) 764 to the APIs above.</li> 765 </ul> 766 <p>A "publicly exposed element" is any construct which is not decorated with 767 the "@hide" marker as used in the upstream Android source code. In other 768 words, device implementers MUST NOT expose new APIs or alter existing APIs in 769 the namespaces noted above. Device implementers MAY make internal-only 770 modifications, but those modifications MUST NOT be advertised or otherwise 771 exposed to developers.</p> 772 <p>Device implementers MAY add custom APIs, but any such APIs MUST NOT be in a 773 namespace owned by or referring to another organization. For instance, device 774 implementers MUST NOT add APIs to the com.google.* or similar namespace; only 775 Google may do so. Similarly, Google MUST NOT add APIs to other companies' 776 namespaces. Additionally, if a device implementation includes custom APIs 777 outside the standard Android namespace, those APIs MUST be packaged in an 778 Android shared library so that only apps that explicitly use them (via the 779 <code><uses-library></code> mechanism) are affected by the increased 780 memory usage of such APIs.</p> 781 <p>If a device implementer proposes to improve one of the package namespaces 782 above (such as by adding useful new functionality to an existing API, or 783 adding a new API), the implementer SHOULD visit source.android.com and begin 784 the process for contributing changes and code, according to the information on 785 that site.</p> 786 <p>Note that the restrictions above correspond to standard conventions for 787 naming APIs in the Java programming language; this section simply aims to 788 reinforce those conventions and make them binding through inclusion in this 789 compatibility definition.</p> 790 791 <a name="section-3.7"></a><h3 id="section-3.7">3.7. Virtual Machine Compatibility</h3> 792 <p>Device implementations MUST support the full Dalvik Executable (DEX) 793 bytecode specification and Dalvik Virtual Machine semantics [<a 794 href="#resources17">Resources, 17</a>].</p> 795 <p>Device implementations MUST configure Dalvik to allocate memory in 796 accordance with the upstream Android platform, and as specified by the following 797 table. (See <a href="#section-7.1.1">Section 7.1.1</a> for screen size and screen 798 density definitions.)</p> 799 800 <p>Note that memory values specified below are considered minimum values, 801 and device implementations MAY allocate more memory per application.</p> 802 <table> 803 <tbody> 804 <tr> 805 <td><b>Screen Size</b></td> 806 <td><b>Screen Density</b></td> 807 <td><b>Application Memory</b></td> 808 </tr> 809 <tr> 810 <td>small / normal / large</td> 811 <td>ldpi / mdpi</td> 812 <td>16MB</td> 813 </tr> 814 <tr> 815 <td>small / normal / large</td> 816 <td>tvdpi / hdpi</td> 817 <td>32MB</td> 818 </tr> 819 <tr> 820 <td>small / normal / large</td> 821 <td>xhdpi</td> 822 <td>64MB</td> 823 </tr> 824 <tr> 825 <td>small / normal / large</td> 826 <td>400dpi</td> 827 <td>96MB</td> 828 </tr> 829 <tr> 830 <td>small / normal / large</td> 831 <td>xxhdpi</td> 832 <td>128MB</td> 833 </tr> 834 <tr> 835 <td>small / normal / large</td> 836 <td>xxxhdpi</td> 837 <td>256MB</td> 838 </tr> 839 <tr> 840 <td>xlarge</td> 841 <td>mdpi</td> 842 <td>32MB</td> 843 </tr> 844 <tr> 845 <td>xlarge</td> 846 <td>tvdpi / hdpi</td> 847 <td>64MB</td> 848 </tr> 849 <tr> 850 <td>xlarge</td> 851 <td>xhdpi</td> 852 <td>128MB</td> 853 </tr> 854 <tr> 855 <td>xlarge</td> 856 <td>400dpi</td> 857 <td>192MB</td> 858 </tr> 859 <tr> 860 <td>xlarge</td> 861 <td>xxhdpi</td> 862 <td>256MB</td> 863 </tr> 864 <tr> 865 <td>xlarge</td> 866 <td>xxxhdpi</td> 867 <td>512MB</td> 868 </tr> 869 </tbody> 870 </table> 871 872 <a name="section-3.8"></a><h3 id="section-3.8">3.8. User Interface Compatibility</h3> 873 874 <a name="section-3.8.1"></a><h4 id="section-3.8.1">3.8.1. Launcher (Home Screen)</h4> 875 <p>Android includes a launcher application (home screen) and support for third party applications to replace the device 876 launcher (home screen). Device implementations that allow third party applications to replace the device home screen 877 MUST declare the platform feature <code>android.software.home_screen</code>.</p> 878 879 <a name="section-3.8.2"></a><h4 id="section-3.8.2">3.8.2. Widgets</h4> 880 <p>Android defines a component type and corresponding API and lifecycle that allows applications to expose an "AppWidget" 881 to the end user [<a href="#resources18">Resources, 18</a>]. Device implementations that support embedding widgets on the 882 home screen MUST meet the following requirements and declare support for platform feature <code>android.software.app_widgets</code>.</p> 883 <ul> 884 <li>Device launchers MUST include built-in support for AppWidgets, and expose user 885 interface affordances to add, configure, view, and remove AppWidgets directly within the Launcher.</li> 886 <li>Device implementations MUST be capable of rendering widgets that are 4 x 4 in the standard grid size. 887 (See the App Widget Design Guidelines in the Android SDK documentation [<a href="#resources18">Resources, 18</a>] for details.</li> 888 <li>Device implementations that include support for lock screen MUST support application widgets on the lock screen.</li> 889 </ul> 890 891 <a name="section-3.8.3"></a><h4 id="section-3.8.3">3.8.3. Notifications</h4> 892 <p>Android includes APIs that allow developers to notify users of notable 893 events [<a href="#resources19">Resources, 19</a>], using hardware and software 894 features of the device.</p> 895 <p>Some APIs allow applications to perform notifications or attract attention 896 using hardware, specifically sound, vibration, and light. Device implementations 897 MUST support notifications that use hardware features, as described in the SDK 898 documentation, and to the extent possible with the device implementation 899 hardware. For instance, if a device implementation includes a vibrator, it 900 MUST correctly implement the vibration APIs. If a device implementation lacks 901 hardware, the corresponding APIs MUST be implemented as no-ops. Note that this 902 behavior is further detailed in <a href="#section-7">Section 7.</a></p> 903 <p>Additionally, the implementation MUST correctly render all resources 904 (icons, sound files, etc.) provided for in the APIs [<a 905 href="#resources20">Resources, 20</a>], or in the 906 Status/System Bar icon style guide [<a href="#resources21">Resources, 21</a>]. 907 Device implementers MAY provide an alternative user experience for 908 notifications than that provided by the reference Android Open Source 909 implementation; however, such alternative notification systems MUST support 910 existing notification resources, as above.</p> 911 <p>Android includes support for rich notifications, such as interactive 912 Views for ongoing notifications. Device implementations MUST properly display 913 and execute rich notifications, as documented in the Android APIs.</p> 914 <a name="section-3.8.4"></a><h4 id="section-3.8.4">3.8.4. Search</h4> 915 <p>Android includes APIs [<a href="#resources22">Resources, 22</a>] that allow 916 developers to incorporate search into their applications, and expose their 917 application's data into the global system search. Generally speaking, this 918 functionality consists of a single, system-wide user interface that allows users 919 to enter queries, displays suggestions as users type, and displays results. The 920 Android APIs allow developers to reuse this interface to provide search within 921 their own apps, and allow developers to supply results to the common global 922 search user interface.</p> 923 <p>Device implementations MUST include a single, shared, system-wide search 924 user interface capable of real-time suggestions in response to user input. 925 Device implementations MUST implement the APIs that allow developers to reuse 926 this user interface to provide search within their own applications. Device 927 implementations MUST implement the APIs that allow third-party applications to 928 add suggestions to the search box when it is run in global search mode. If no 929 third-party applications are installed that make use of this functionality, 930 the default behavior SHOULD be to display web search engine results and 931 suggestions.</p> 932 <a name="section-3.8.5"></a><h4 id="section-3.8.5">3.8.5. Toasts</h4> 933 <p>Applications can use the "Toast" API (defined in [<a 934 href="#resources23">Resources, 23</a>]) to 935 display short non-modal strings to the end user, that disappear after a brief 936 period of time. Device implementations MUST display Toasts from applications 937 to end users in some high-visibility manner.</p> 938 939 <a name="section-3.8.6"></a><h4 id="section-3.8.6">3.8.6. Themes</h4> 940 <p>Android provides "themes" as a mechanism for applications to apply styles 941 across an entire Activity or application.</p> 942 <p>Android includes a "Holo" theme family as a set of defined styles for 943 application developers to use if they want to match the Holo theme look and 944 feel as defined by the Android SDK [<a href="#resources24">Resources, 24</a>]. 945 Device implementations MUST NOT alter any of the Holo theme attributes exposed 946 to applications [<a href="#resources25">Resources, 25</a>].</p> 947 <p>Android also includes a "Device Default" theme family as a set of defined 948 styles for application developers to use if they want to match the look and feel 949 of the device theme as defined by the device implementer. Device implementations 950 MAY modify the DeviceDefault theme attributes exposed to applications 951 [<a href="#resources25">Resources, 25</a>].</p> 952 <p>From version 4.4, Android now supports a new variant theme with translucent system bars, 953 allowing application developers to fill the area behind the status and 954 navigation bar with their app content. To enable a consistent developer 955 experience in this configuration, it is important the status bar icon style 956 is maintained across different device implementations. Therefore, Android 957 device implementations MUST use white for system status icons (such as signal 958 strength and battery level) and notifications issued by the system, unless the 959 icon is indicating a problematic status 960 [<a href="#resources25">Resources, 25</a>].</p> 961 962 <a name="section-3.8.7"></a><h4 id="section-3.8.7">3.8.7. Live Wallpapers</h4> 963 <p>Android defines a component type and corresponding API and lifecycle that 964 allows applications to expose one or more "Live Wallpapers" to the end user 965 [<a href="#resources26">Resources, 26</a>]. Live Wallpapers are animations, 966 patterns, or similar images with limited input capabilities that display as a 967 wallpaper, behind other applications.</p> 968 <p>Hardware is considered capable of reliably running live wallpapers if it 969 can run all live wallpapers, with no limitations on functionality, at a 970 reasonable framerate with no adverse affects on other applications. If 971 limitations in the hardware cause wallpapers and/or applications to crash, 972 malfunction, consume excessive CPU or battery power, or run at unacceptably 973 low frame rates, the hardware is considered incapable of running live 974 wallpaper. As an example, some live wallpapers may use an Open GL 1.0 or 2.0 975 context to render their content. Live wallpaper will not run reliably on 976 hardware that does not support multiple OpenGL contexts because the live 977 wallpaper use of an OpenGL context may conflict with other applications that 978 also use an OpenGL context.</p> 979 <p>Device implementations capable of running live wallpapers reliably as 980 described above SHOULD implement live wallpapers. Device implementations 981 determined to not run live wallpapers reliably as described above MUST NOT 982 implement live wallpapers.</p> 983 <a name="section-3.8.8"></a><h4 id="section-3.8.8">3.8.8. Recent Application Display</h4> 984 <p>The upstream Android source code includes a user interface for 985 displaying recent applications using a thumbnail image of the application's 986 graphical state at the moment the user last left the application. Device 987 implementations MAY alter or eliminate this user interface; however, a future 988 version of Android is planned to make more extensive use of this 989 functionality. Device implementations are strongly encouraged to use the 990 upstream Android user interface (or a similar thumbnail-based interface) 991 for recent applications, or else they may not be compatible with a future 992 version of Android.</p> 993 <a name="section-3.8.9"></a><h4 id="section-3.8.9">3.8.9. Input Management</h4> 994 <p>Android includes support for Input Management and support for third party input method editors. 995 Device implementations that allow users to use third party input methods on the device MUST declare the platform feature 996 <code>android.software.input_methods</code> and support IME APIs as defined in the Android SDK documentation.</p> 997 <p>Device implementations that declare the <code>android.software.input_methods</code> feature MUST provide a user-accessible mechanism 998 to add and configure third party input methods. Device implementations MUST display the settings interface in response to the 999 <code>android.settings.INPUT_METHOD_SETTINGS</code> intent.</p> 1000 1001 <a name="section-3.8.10"></a><h4 id="section-3.8.10">3.8.10. Lock Screen Media Remote Control</h4> 1002 <p>Android includes support for Remote Control API that lets media applications integrate with playback controls 1003 that are displayed in a remote view like the device lock screen [<a href="#resources74">Resources, 74</a>]. Device implementations 1004 that support lock screen in the device and allow users to add widgets on the home screen MUST 1005 include support for embedding remote controls in the device lock screen [<a href="#resources69">Resources, 69</a>].</p> 1006 1007 <a name="section-3.8.11"></a><h4 id="section-3.8.11">3.8.11. Dreams</h4> 1008 <p>Android includes support for interactive screensavers called Dreams [<a href="#resources76">Resources, 76</a>]. 1009 Dreams allows users to interact with applications when a charging device is idle, or docked in a desk dock. Device implementations 1010 MUST include support for Dreams and provide a settings option for users to configure Dreams.</p> 1011 1012 <a name="section-3.8.12"></a><h4 id="section-3.8.12">3.8.12. Location</h4> 1013 <p>Location modes MUST be displayed in the Location menu within Settings [<a 1014 href="#resources87">Resources, 87</a>]. Location services provided through the 1015 <code>SettingInjectorService</code> introduced in Android 4.4 must be displayed 1016 in the same Location menu [<a href="#resources89">Resources, 89</a>].</p> 1017 1018 <a name="section-3.8.13"></a><h4 id="section-3.8.13">3.8.13. Unicode</h4> 1019 <p>Android 4.4 includes support for color emoji characters. Android device 1020 implementations MUST provide an input method to the user for the Emoji 1021 characters defined in Unicode 6.1 [<a href="#resources82">Resources, 82</a>] 1022 and MUST be capable of rendering these emoji characters in color glyph.</p> 1023 1024 <a name="section-3.9"></a><h3 id="section-3.9">3.9. Device Administration</h3> 1025 <p>Android includes features that allow security-aware applications 1026 to perform device administration functions at the system level, such as enforcing 1027 password policies or performing remote wipe, through the Android Device 1028 Administration API [<a href="#resources27">Resources, 27</a>]. Device 1029 implementations MUST provide an implementation of the <code>DevicePolicyManager</code> 1030 class [<a href="#resources28">Resources, 28</a>]. Device implementations that include support for lock screen 1031 MUST support the full range of device administration policies defined in the Android SDK 1032 documentation [<a href="#resources27">Resources, 27</a>].</p> 1033 <p>Device implementations MAY have a preinstalled application performing device 1034 administration functions but this application MUST NOT be set out-of-the box 1035 as the default Device Owner app [<a href="#resources84">Resources, 84</a>].</p> 1036 1037 <a name="section-3.10"></a><h3 id="section-3.10">3.10. Accessibility</h3> 1038 <p>Android provides an accessibility layer that helps users with disabilities 1039 to navigate their devices more easily. In addition, Android provides 1040 platform APIs that enable accessibility service implementations to receive 1041 callbacks for user and system events and generate alternate feedback mechanisms, 1042 such as text-to-speech, haptic feedback, and trackball/d-pad navigation 1043 [<a href="#resources29">Resources, 29</a>]. Device implementations MUST provide an 1044 implementation of the Android accessibility framework consistent with the 1045 default Android implementation. Specifically, device implementations MUST meet 1046 the following requirements.</p> 1047 <ul> 1048 <li>Device implementations MUST support third party accessibility service 1049 implementations through the <code>android.accessibilityservice</code> 1050 APIs [<a href="#resources30">Resources, 30</a>].</li> 1051 <li>Device implementations MUST generate <code>AccessibilityEvents</code> 1052 and deliver these events to all registered <code>AccessibilityService 1053 </code> implementations in a manner consistent with the default Android 1054 implementation.</li> 1055 <li>Device implementations MUST provide a user-accessible mechanism to enable 1056 and disable accessibility services, and MUST display this interface in 1057 response to the 1058 <code>android.provider.Settings.ACTION_ACCESSIBILITY_SETTINGS</code> 1059 intent.</li> 1060 </ul> 1061 <p>Additionally, device implementations SHOULD provide an implementation 1062 of an accessibility service on the device, and SHOULD provide a mechanism 1063 for users to enable the accessibility service during device setup. An open 1064 source implementation of an accessibility service is available from the Eyes 1065 Free project [<a href="#resources31">Resources, 31</a>].</p> 1066 1067 <a name="section-3.11"></a><h3 id="section-3.11">3.11. Text-to-Speech</h3> 1068 <p>Android includes APIs that allow applications to make use of 1069 text-to-speech (TTS) services, and allows service providers to provide 1070 implementations of TTS services [<a href="#resources32">Resources, 32</a>]. 1071 Device implementations MUST meet these requirements related to the Android TTS 1072 framework:</p> 1073 <ul> 1074 <li>Device implementations MUST support the Android TTS framework APIs and 1075 SHOULD include a TTS engine supporting the languages available on the 1076 device. Note that the upstream Android open source software includes a 1077 full-featured TTS engine implementation.</li> 1078 <li>Device implementations MUST support installation of third-party TTS 1079 engines.</li> 1080 <li>Device implementations MUST provide a user-accessible interface that allows 1081 users to select a TTS engine for use at the system level.</li> 1082 </ul> 1083 1084 <a name="section-4"></a><h2 id="section-4">4. Application Packaging Compatibility</h2> 1085 <p>Device implementations MUST install and run Android ".apk" files as 1086 generated by the "aapt" tool included in the official Android SDK [<a 1087 href="#resources33">Resources, 33</a>].</p> 1088 <p>Devices implementations MUST NOT extend either the .apk [<a 1089 href="#resources34">Resources, 34</a>], Android Manifest [<a 1090 href="#resources35">Resources, 35</a>], 1091 Dalvik bytecode [<a href="#resources17">Resources, 17</a>], or renderscript 1092 bytecode formats in such a way that would prevent those files from installing 1093 and running correctly on other compatible devices. Device implementers SHOULD 1094 use the reference upstream implementation of Dalvik, and the reference 1095 implementation's package management system.</p> 1096 1097 <a name="section-5"></a><h2 id="section-5">5. Multimedia Compatibility</h2> 1098 <p>Device implementations MUST include at least one form of audio output, such as 1099 speakers, headphone jack, external speaker connection, etc.</p> 1100 <a name="section-5.1"></a><h3 id="section-5.1">5.1. Media Codecs</h3> 1101 <p>Device implementations MUST support the core media formats specified 1102 in the Android SDK documentation [<a href="#resources58">Resources, 58</a>] except 1103 where explicitly permitted in this document. Specifically, device implementations 1104 MUST support the media formats, encoders, decoders, file types and container 1105 formats defined in the tables below. All of these codecs are provided as 1106 software implementations in the preferred Android implementation from the Android 1107 Open Source Project.</p> 1108 1109 <p><strong>Please note that neither Google nor the Open Handset Alliance make any 1110 representation that these codecs are unencumbered by third-party patents. 1111 Those intending to use this source code in hardware or software products are 1112 advised that implementations of this code, including in open source software 1113 or shareware, may require patent licenses from the relevant patent 1114 holders.</strong></p> 1115 1116 <p>Note that these tables do not list specific bitrate requirements for 1117 most video codecs because current device hardware does not necessarily support 1118 bitrates that map exactly to the required bitrates specified by the relevant 1119 standards. Instead, device implementations SHOULD support the highest bitrate 1120 practical on the hardware, up to the limits defined by the specifications.</p> 1121 <div style="page-break-before: always;"></div> 1122 <table> 1123 <tbody> 1124 1125 <tr> 1126 <th>Type</th> 1127 <th>Format / Codec</th> 1128 <th>Encoder</th> 1129 <th>Decoder</th> 1130 <th>Details</th> 1131 <th>File Type(s) / Container Formats</th> 1132 </tr> 1133 1134 <tr> 1135 <td rowspan="11">Audio</td> 1136 <td>MPEG-4 AAC Profile (AAC LC)</td> 1137 <td>REQUIRED for device implementations that include microphone hardware 1138 and define <code>android.hardware.microphone</code>.</td> 1139 <td style="text-align: center;">REQUIRED</td> 1140 <td rowspan="1"> Support for mono/stereo/5.0/5.1* content with standard sampling rates from 8 to 48 kHz.</td> 1141 <td rowspan="4"> 1142 <ul> 1143 <li>3GPP (.3gp)</li> 1144 <li>MPEG-4 (.mp4, .m4a)</li> 1145 <li>ADTS raw AAC (.aac, decode in Android 3.1+, encode in Android 4.0+, ADIF not supported)</li> 1146 <li>MPEG-TS (.ts, not seekable, Android 3.0+)</li> 1147 </ul> 1148 </td> 1149 </tr> 1150 1151 <tr> 1152 <td>MPEG-4 HE AAC Profile (AAC+)</td> 1153 <td>REQUIRED for device implementations that include microphone hardware and define android.hardware.microphone</td> 1154 <td style="text-align: center;">REQUIRED</td> 1155 <td>Support for mono/stereo/5.0/5.1* content with standard sampling rates from 16 to 48 kHz.</td> 1156 </tr> 1157 1158 <tr> 1159 <td>MPEG-4 HE AAC v2 Profile (enhanced AAC+)</td> 1160 <td> </td> 1161 <td style="text-align: center;">REQUIRED</td> 1162 <td>Support for mono/stereo/5.0/5.1* content with standard sampling rates from 16 to 48 kHz.</td> 1163 </tr> 1164 1165 <tr> 1166 <td>MPEG-4 Audio Object Type ER AAC ELD (Enhanced Low Delay AAC)</td> 1167 <td>REQUIRED for device implementations that include microphone hardware and define android.hardware.microphone</td> 1168 <td style="text-align: center;">REQUIRED</td> 1169 <td>Support for mono/stereo content with standard 1170 sampling rates from 16 to 48 kHz.</td> 1171 </tr> 1172 1173 <tr> 1174 <td>AMR-NB</td> 1175 <td>REQUIRED for device implementations that include microphone hardware 1176 and define <code>android.hardware.microphone</code>.</td> 1177 <td style="text-align: center;">REQUIRED</td> 1178 <td>4.75 to 12.2 kbps sampled @ 8kHz</td> 1179 <td>3GPP (.3gp) 1180 </td> 1181 </tr> 1182 1183 <tr> 1184 <td>AMR-WB</td> 1185 <td>REQUIRED for device implementations that include microphone hardware 1186 and define <code>android.hardware.microphone</code>.</td> 1187 <td style="text-align: center;">REQUIRED</td> 1188 <td>9 rates from 6.60 kbit/s to 23.85 kbit/s sampled @ 16kHz</td> 1189 <td>3GPP (.3gp)</td> 1190 </tr> 1191 1192 <tr> 1193 <td>FLAC</td> 1194 <td> </td> 1195 <td style="text-align: center;">REQUIRED<br/><small>(Android 3.1+)</small></td> 1196 <td>Mono/Stereo (no multichannel). Sample rates up to 48 kHz (but up to 44.1 1197 kHz is recommended on devices with 44.1 kHz output, as the 48 to 44.1 kHz 1198 downsampler does not include a low-pass filter). 16-bit recommended; 1199 no dither applied for 24-bit. 1200 </td> 1201 <td>FLAC (.flac) only</td> 1202 </tr> 1203 1204 <tr> 1205 <td>MP3</td> 1206 <td> </td> 1207 <td style="text-align: center;">REQUIRED</td> 1208 <td>Mono/Stereo 8-320Kbps constant (CBR) or variable bit-rate (VBR) 1209 </td> 1210 <td>MP3 (.mp3)</td> 1211 </tr> 1212 1213 <tr> 1214 <td>MIDI</td> 1215 <td> </td> 1216 <td style="text-align: center;">REQUIRED</td> 1217 <td>MIDI Type 0 and 1. DLS Version 1 and 2. XMF and Mobile XMF. Support for ringtone formats RTTTL/RTX, OTA, and iMelody </td> 1218 <td> 1219 <ul> 1220 <li>Type 0 and 1 (.mid, .xmf, .mxmf)</li> 1221 <li>RTTTL/RTX (.rtttl, .rtx)</li> 1222 <li>OTA (.ota)</li> 1223 <li>iMelody (.imy)</li> 1224 </ul> 1225 </td> 1226 </tr> 1227 1228 <tr> 1229 <td>Vorbis</td> 1230 <td> </td> 1231 <td style="text-align: center;">REQUIRED</td> 1232 <td> </td> 1233 <td> 1234 <ul> 1235 <li>Ogg (.ogg)</li> 1236 <li>Matroska (.mkv)</li> 1237 </ul> 1238 </td> 1239 </tr> 1240 1241 <tr> 1242 <td>PCM/WAVE</td> 1243 <td style="text-align: center;">REQUIRED</td> 1244 <td style="text-align: center;">REQUIRED</td> 1245 <td>8-bit and 16-bit linear PCM** (rates up to limit of hardware).Devices MUST support sampling rates 1246 for raw PCM recording at 8000,16000 and 44100 Hz frequencies</td> 1247 <td>WAVE (.wav)</td> 1248 </tr> 1249 1250 <tr> 1251 <td rowspan="5">Image</td> 1252 <td>JPEG</td> 1253 <td style="text-align: center;">REQUIRED</td> 1254 <td style="text-align: center;">REQUIRED</td> 1255 <td>Base+progressive</td> 1256 <td>JPEG (.jpg)</td> 1257 </tr> 1258 1259 <tr> 1260 <td>GIF</td> 1261 <td> </td> 1262 <td style="text-align: center;">REQUIRED</td> 1263 <td> </td> 1264 <td>GIF (.gif)</td> 1265 </tr> 1266 1267 <tr> 1268 <td>PNG</td> 1269 <td style="text-align: center;">REQUIRED</td> 1270 <td style="text-align: center;">REQUIRED</td> 1271 <td> </td> 1272 <td>PNG (.png)</td> 1273 </tr> 1274 1275 <tr> 1276 <td>BMP</td> 1277 <td> </td> 1278 <td style="text-align: center;">REQUIRED</td> 1279 <td> </td> 1280 <td>BMP (.bmp)</td> 1281 </tr> 1282 1283 1284 <tr> 1285 <td>WEBP</td> 1286 <td style="text-align: center;">REQUIRED</td> 1287 <td style="text-align: center;">REQUIRED</td> 1288 <td> </td> 1289 <td>WebP (.webp)</td> 1290 </tr> 1291 1292 <tr> 1293 <td rowspan="5">Video</td> 1294 <td>H.263</td> 1295 <td>REQUIRED for device implementations that include camera hardware 1296 and define <code>android.hardware.camera</code> or 1297 <code>android.hardware.camera.front</code>.</td> 1298 <td style="text-align: center;">REQUIRED</td> 1299 <td> </td> 1300 <td> 1301 <ul> 1302 <li>3GPP (.3gp)</li> 1303 <li>MPEG-4 (.mp4)</li> 1304 </ul> 1305 </td> 1306 </tr> 1307 1308 <tr> 1309 <td>H.264 AVC</td> 1310 <td>REQUIRED for device implementations that include camera hardware 1311 and define <code>android.hardware.camera</code> or 1312 <code>android.hardware.camera.front</code>.</td> 1313 <td style="text-align: center;">REQUIRED</td> 1314 <td>Baseline Profile (BP)</td> 1315 <td> 1316 <ul> 1317 <li>3GPP (.3gp)</li> 1318 <li>MPEG-4 (.mp4)</li> 1319 <li>MPEG-TS (.ts, AAC audio only, not seekable, Android 3.0+)</li> 1320 </ul> 1321 </td> 1322 </tr> 1323 1324 <tr> 1325 <td>MPEG-4 SP</td> 1326 <td> </td> 1327 <td style="text-align: center;">REQUIRED</td> 1328 <td> </td> 1329 <td>3GPP (.3gp)</td> 1330 </tr> 1331 1332 <tr> 1333 <td>VP8****</td> 1334 <td style="text-align: center;">REQUIRED<br/><small>(Android 4.3+)</small></td> 1335 <td style="text-align: center;">REQUIRED<br/><small>(Android 2.3.3+)</small></td> 1336 <td> </td> 1337 <td><a href="http://www.webmproject.org/">WebM</a> (.webm) and Matroska (.mkv, Android 4.0+)***</td> 1338 </tr> 1339 1340 <tr> 1341 <td>VP9</td> 1342 <td> </td> 1343 <td style="text-align: center;">REQUIRED<br/><small>(Android 4.4+)</small></td> 1344 <td> </td> 1345 <td><a href="http://www.webmproject.org/">WebM</a> (.webm) and Matroska (.mkv, 1346 Android 4.0+)***</td> 1347 </tr> 1348 1349 </tbody></table> 1350 <ul> 1351 <li>*Note: Only downmix of 5.0/5.1 content is required; recording or rendering more than 2 channels is optional.</li> 1352 <li>**Note: 16-bit linear PCM capture is mandatory. 8-bit linear PCM capture is not mandatory.</li> 1353 <li>***Note: Device implementations SHOULD support writing Matroska WebM files.</li> 1354 <li>****Note: For acceptable quality of web video streaming and video-conference 1355 services, device implementations SHOULD use a hardware VP8 codec that meets the 1356 requirements in [<a href="#resources86">Resources, 86</a>].</li> 1357 </ul> 1358 1359 <a name="section-5.2"></a><h3 id="section-5.2">5.2. Video Encoding</h3> 1360 <p>Android device implementations that include a rear-facing camera and declare 1361 <code>android.hardware.camera</code> SHOULD support the following H.264 video encoding 1362 profiles.</p> 1363 <table> 1364 <thead> 1365 <tr> 1366 <th> </th> 1367 <th>SD (Low quality)</th> 1368 <th>SD (High quality)</th> 1369 <th>HD (When supported by hardware)</th> 1370 </tr> 1371 </thead> 1372 <tbody> 1373 <tr> 1374 <th>Video resolution</th> 1375 <td>176 x 144 px</td> 1376 <td>480 x 360 px</td> 1377 <td>1280 x 720 px</td> 1378 </tr> 1379 <tr> 1380 <th>Video frame rate</th> 1381 <td>12 fps</td> 1382 <td>30 fps</td> 1383 <td>30 fps</td> 1384 </tr> 1385 <tr> 1386 <th>Video bitrate</th> 1387 <td>56 Kbps</td> 1388 <td>500 Kbps or higher</td> 1389 <td>2 Mbps or higher</td> 1390 </tr> 1391 <tr> 1392 <th>Audio codec</th> 1393 <td>AAC-LC</td> 1394 <td>AAC-LC</td> 1395 <td>AAC-LC</td> 1396 </tr> 1397 <tr> 1398 <th>Audio channels</th> 1399 <td>1 (mono)</td> 1400 <td>2 (stereo)</td> 1401 <td>2 (stereo)</td> 1402 </tr> 1403 <tr> 1404 <th>Audio bitrate</th> 1405 <td>24 Kbps</td> 1406 <td>128 Kbps</td> 1407 <td>192 Kbps</td> 1408 </tr> 1409 </tbody> 1410 </table> 1411 1412 <p>Android device implementations that include a rear-facing camera and declare 1413 <code>android.hardware.camera</code> SHOULD support the following VP8 video encoding profiles</p> 1414 <table> 1415 <thead> 1416 <tr> 1417 <th> </th> 1418 <th>SD (Low quality)</th> 1419 <th>SD (High quality)</th> 1420 <th>HD 720p <br/> (When supported by hardware)</th> 1421 <th>HD 1080p <br/>(When supported by hardware)</th> 1422 </tr> 1423 </thead> 1424 <tbody> 1425 <tr> 1426 <th>Video resolution</th> 1427 <td>320 x 180 px</td> 1428 <td>640 x 360 px</td> 1429 <td>1280 x 720 px</td> 1430 <td>1920 x 1080 px</td> 1431 </tr> 1432 <tr> 1433 <th>Video frame rate</th> 1434 <td>30 fps</td> 1435 <td>30 fps</td> 1436 <td>30 fps</td> 1437 <td>30 fps</td> 1438 </tr> 1439 <tr> 1440 <th>Video bitrate</th> 1441 <td>800 Kbps</td> 1442 <td>2 Mbps</td> 1443 <td>4 Mbps</td> 1444 <td>10 Mbps</td> 1445 </tr> 1446 </tbody> 1447 </table> 1448 1449 <a name="section-5.3"></a><h3 id="section-5.3">5.3. Video Decoding</h3> 1450 <p>Android device implementations SHOULD support the following VP8, VP9 and 1451 H.264 video decoding profiles. Device implementations SHOULD also support 1452 dynamic video resolution switching within the same stream for VP8, VP9 and 1453 H.264 codecs.</p> 1454 <table> 1455 <thead> 1456 <tr> 1457 <th> </th> 1458 <th>SD (Low quality)</th> 1459 <th>SD (High quality)</th> 1460 <th>HD 720p <br/> (When supported by hardware)</th> 1461 <th>HD 1080p <br/>(When supported by hardware)</th> 1462 </tr> 1463 </thead> 1464 <tbody> 1465 <tr> 1466 <th>Video resolution</th> 1467 <td>320 x 180 px</td> 1468 <td>640 x 360 px</td> 1469 <td>1280 x 720 px</td> 1470 <td>1920 x 1080 px</td> 1471 </tr> 1472 <tr> 1473 <th>Video frame rate</th> 1474 <td>30 fps</td> 1475 <td>30 fps</td> 1476 <td>30 fps</td> 1477 <td>30 fps</td> 1478 </tr> 1479 <tr> 1480 <th>Video bitrate</th> 1481 <td>800 Kbps</td> 1482 <td>2 Mbps</td> 1483 <td>8 Mbps</td> 1484 <td>20 Mbps</td> 1485 </tr> 1486 </tbody> 1487 </table> 1488 1489 <a name="section-5.4"></a><h3 id="section-5.4">5.4. Audio Recording</h3> 1490 <p>When an application has used the <code>android.media.AudioRecord</code> API to 1491 start recording an audio stream, device implementations that include microphone 1492 hardware and declare <code>android.hardware.microphone</code> MUST sample and 1493 record audio with each of these behaviors:</p> 1494 <ul> 1495 <li>The device SHOULD exhibit approximately flat amplitude versus frequency 1496 characteristics; specifically, ±3 dB, from 100 Hz to 4000 Hz</li> 1497 <li>Audio input sensitivity SHOULD be set such that a 90 dB sound power level 1498 (SPL) source at 1000 Hz yields RMS of 2500 for 16-bit samples.</li> 1499 <li>PCM amplitude levels SHOULD linearly track input SPL changes over at least 1500 a 30 dB range from -18 dB to +12 dB re 90 dB SPL at the microphone.</li> 1501 <li>Total harmonic distortion SHOULD be less than 1% for 1Khz at 90 dB SPL input level.</li> 1502 </ul> 1503 <p>In addition to the above recording specifications, when an application has 1504 started recording an audio stream using the 1505 <code>android.media.MediaRecorder.AudioSource.VOICE_RECOGNITION</code> audio 1506 source:</p> 1507 <ul> 1508 <li>Noise reduction processing, if present, MUST be disabled.</li> 1509 <li>Automatic gain control, if present, MUST be disabled.</li> 1510 </ul> 1511 <p>From Android 4.4, <code>android.media.MediaRecorder.AudioSource</code> class has a new 1512 audio source: <code>REMOTE_SUBMIX</code>. Devices MUST properly implement the 1513 <code>REMOTE_SUBMIX</code> audio source so that when an application uses the 1514 <code>android.media.AudioRecord</code> API to record from this audio source, 1515 it can capture a mix of all audio streams except for the following:</p> 1516 <ul> 1517 <li><code>STREAM_RING</code></li> 1518 <li><code>STREAM_ALARM</code></li> 1519 <li><code>STREAM_NOTIFICATION</code></li> 1520 </ul> 1521 <p><b>Note:</b> while some of the requirements outlined above are stated as 1522 "SHOULD" since Android 4.3, the Compatibility Definition for a future version 1523 is planned to change these to "MUST". That is, these requirements are optional 1524 in Android 4.4 but <b>will be required</b> by a future version. Existing and new 1525 devices that run Android are <b>very strongly encouraged to meet these 1526 requirements</b>, or they will not be able to attain Android 1527 compatibility when upgraded to the future version.</p> 1528 <p>If the platform supports noise suppression technologies tuned for speech 1529 recognition, the effect MUST be controllable from the 1530 <code>android.media.audiofx.NoiseSuppressor</code> API. Moreover, the "uuid" 1531 field for the noise suppressor's effect descriptor MUST uniquely identify each 1532 implementation of the noise suppression technology.</p> 1533 1534 <a name="section-5.5"></a><h3 id="section-5.5">5.5. Audio Latency</h3> 1535 <p>Audio latency is the time delay as an audio signal passes through a system. 1536 Many classes of 1537 applications rely on short latencies, to achieve real-time sound effects.</p> 1538 <p>For the purposes of this section:</p> 1539 <ul> 1540 <li>"output latency" is defined as the interval between when an application 1541 writes a frame of PCM-coded data and when the corresponding sound can be heard 1542 by an external listener or observed by a transducer</li> 1543 <li>"cold output latency" is defined as the output latency for the first frame, when 1544 the audio output system has been idle and powered down prior to the request</li> 1545 <li>"continuous output latency" is defined as the output latency for subsequent frames, 1546 after the device is already playing audio</li> 1547 <li>"input latency" is the interval between when an external sound is presented 1548 to the device and when an application reads the corresponding frame of PCM-coded data</li> 1549 <li>"cold input latency" is defined as the sum of lost input time 1550 and the input latency for the first frame, when 1551 the audio input system has been idle and powered down prior to the request</li> 1552 <li>"continuous input latency" is defined as the input latency for subsequent frames, 1553 while the device is already capturing audio</li> 1554 <li>"OpenSL ES PCM buffer queue API" is the set of PCM-related OpenSL ES APIs within Android NDK; 1555 see <i>NDK_root</i><code>/docs/opensles/index.html</code></li> 1556 </ul> 1557 <p>Per <a href="#section-5">Section 5</a>, 1558 all compatible device implementations MUST include at least one form of audio output. 1559 Device implementations SHOULD meet or exceed these output latency requirements:</p> 1560 <ul> 1561 <li>cold output latency of 100 milliseconds or less</li> 1562 <li>continuous output latency of 45 milliseconds or less</li> 1563 </ul> 1564 <p>If a device implementation meets the requirements of this section 1565 after any initial calibration 1566 when using the OpenSL ES PCM buffer queue API, 1567 for continuous output latency and cold output latency 1568 over at least one supported audio output device, it MAY 1569 report support for low-latency audio, by reporting the feature 1570 "android.hardware.audio.low-latency" via the 1571 <code>android.content.pm.PackageManager</code> class. [<a 1572 href="#resources37">Resources, 37</a>] Conversely, if the device 1573 implementation does not meet these requirements it MUST NOT report support for 1574 low-latency audio.</p> 1575 <p> 1576 Per <a href="#section-7.2.5">Section 7.2.5</a>, 1577 microphone hardware may be omitted by device implementations.</p> 1578 <p> 1579 Device implementations that include microphone 1580 hardware and declare <code>android.hardware.microphone</code> SHOULD 1581 meet these input audio latency requirements:</p> 1582 <ul> 1583 <li>cold input latency of 100 milliseconds or less</li> 1584 <li>continuous input latency of 50 milliseconds or less</li> 1585 </ul> 1586 1587 <a name="section-5.6"></a><h3 id="section-5.6">5.6. Network Protocols</h3> 1588 <p>Devices MUST support the media network protocols for audio and video playback 1589 as specified in the Android SDK documentation 1590 [<a href="#resources58">Resources, 58</a>]. Specifically, devices MUST support 1591 the following media network protocols:</p> 1592 <ul> 1593 <li>RTSP (RTP, SDP)</li> 1594 <li>HTTP(S) progressive streaming</li> 1595 <li>HTTP(S) Live Streaming draft protocol, Version 3 [<a href="#resources59">Resources, 59</a>]</li> 1596 </ul> 1597 <a name="section-6"></a><h2 id="section-6">6. Developer Tools and Options Compatibility</h2> 1598 1599 <a name="section-6.1"></a><h3 id="section-6.1">6.1. Developer Tools</h3> 1600 <p>Device implementations MUST support the Android Developer Tools provided in the Android SDK. 1601 Specifically, Android-compatible devices MUST be compatible with:</p> 1602 <ul> 1603 <li><b>Android Debug Bridge (known as adb)</b> [<a href="#resources33">Resources, 33</a>]<br/> 1604 Device implementations MUST support all <code>adb</code> functions as 1605 documented in the Android SDK. The device-side <code>adb</code> daemon MUST 1606 be inactive by default, and there MUST be a user-accessible mechanism to turn 1607 on the Android Debug Bridge.</li> 1608 <li>Android includes support for secure adb. Secure adb enables adb on known authenticated hosts. 1609 Device implementations MUST support secure adb.</li> 1610 <li><b>Dalvik Debug Monitor Service (known as ddms)</b> [<a href="#resources33">Resources, 33</a>]<br/> 1611 Device implementations MUST support all <code>ddms</code> features as documented in the 1612 Android SDK. As <code>ddms</code> uses <code>adb</code>, support for 1613 <code>ddms</code> SHOULD be inactive by default, 1614 but MUST be supported whenever the user has activated the Android Debug 1615 Bridge, as above.</li> 1616 <li><b>Monkey</b> [<a href="#resources36">Resources, 36</a>]<br/> 1617 Device implementations MUST include the Monkey framework, and make it 1618 available for applications to use.</li> 1619 <li><b>SysTrace</b> [<a href="#resources33">Resources, 33</a>]<br/> 1620 Device implementations MUST support systrace tool as documented in the Android SDK. 1621 Systrace must be inactive by default, and there MUST be a user-accessible mechanism to turn 1622 on Systrace.</li> 1623 </ul> 1624 <p>Most Linux-based systems and Apple Macintosh systems recognize Android 1625 devices using the standard Android SDK tools, without additional support; 1626 however Microsoft Windows systems typically require a driver for new Android 1627 devices. (For instance, new vendor IDs and sometimes new device IDs require 1628 custom USB drivers for Windows systems.) If a device implementation is 1629 unrecognized by the <code>adb</code> tool as provided in the standard Android 1630 SDK, device implementers MUST provide Windows drivers allowing developers to 1631 connect to the device using the <code>adb</code> protocol. These drivers MUST 1632 be provided for Windows XP, Windows Vista, Windows 7, and Windows 8, in both 32-bit and 1633 64-bit versions.</p> 1634 1635 <a name="section-6.2"></a><h3 id="section-6.2">6.2. Developer Options</h3> 1636 <p>Android includes support for developers to configure application development-related settings. 1637 Device implementations MUST honor the android.settings.APPLICATION_DEVELOPMENT_SETTINGS intent to show 1638 application development-related settings [<a href="#resources77">Resources, 77</a>]. The upstream Android 1639 implementation hides the Developer Options menu by default, and enables users to launch Developer Options 1640 after pressing seven (7) times on the Settings > About Device > Build Number menu item. Device implementations 1641 MUST provide a consistent experience for Developer Options. Specifically, device implementations MUST hide 1642 Developer Options by default and MUST provide a mechanism to enable Developer Options that is consistent with 1643 the upstream Android implementation.</p> 1644 1645 <a name="section-6.2.1"></a><h4 id="section-6.2.1">6.2.1. Experimental</h4> 1646 <p>Android 4.4 introduces ART, an experimental Android runtime, accessible 1647 within the Developer Options menu for preview. Device 1648 implementations SHOULD include ART (libart.so) and support dual boot from 1649 Developer Options, but MUST keep Dalvik (libdvm.so) as the default runtime.</p> 1650 1651 <a name="section-7"></a><h2 id="section-7">7. Hardware Compatibility</h2> 1652 <p>If a device includes a particular hardware component that has a 1653 corresponding API for third-party developers, the device implementation MUST 1654 implement that API as described in the Android SDK documentation. If an API in 1655 the SDK interacts with a hardware component that is stated to be optional and 1656 the device implementation does not possess that component:</p> 1657 <ul> 1658 <li>complete class definitions (as documented by the SDK) for the component's 1659 APIs MUST still be present</li> 1660 <li>the API's behaviors MUST be implemented as no-ops in some reasonable 1661 fashion</li> 1662 <li>API methods MUST return null values where permitted by the SDK 1663 documentation</li> 1664 <li>API methods MUST return no-op implementations of classes where null 1665 values are not permitted by the SDK documentation</li> 1666 <li>API methods MUST NOT throw exceptions not documented by the SDK 1667 documentation</li> 1668 </ul> 1669 <p>A typical example of a scenario where these requirements apply is the 1670 telephony API: even on non-phone devices, these APIs must be implemented as 1671 reasonable no-ops.</p> 1672 <p>Device implementations MUST accurately report accurate hardware configuration 1673 information via the <code>getSystemAvailableFeatures()</code> and 1674 <code>hasSystemFeature(String)</code> methods on the 1675 <code>android.content.pm.PackageManager</code> class. [<a 1676 href="#resources37">Resources, 37</a>]</p> 1677 1678 <a name="section-7.1"></a><h3 id="section-7.1">7.1. Display and Graphics</h3> 1679 <p>Android includes facilities that automatically adjust application 1680 assets and UI layouts appropriately for the device, to ensure that third-party 1681 applications run well on a variety of hardware configurations [<a 1682 href="#resources38">Resources, 38</a>]. Devices MUST properly implement these 1683 APIs and behaviors, as detailed in this section.</p> 1684 1685 <p>The units referenced by the requirements in this section are defined as follows:</p> 1686 <ul> 1687 <li>"Physical diagonal size" is the distance in inches between two opposing 1688 corners of the illuminated portion of the display.</li> 1689 <li>"dpi" (meaning "dots per inch") is the number of pixels encompassed by a 1690 linear horizontal or vertical span of 1". Where dpi values are listed, both 1691 horizontal and vertical dpi must fall within the range.</li> 1692 <li>"Aspect ratio" is the ratio of the longer dimension of the screen to the 1693 shorter dimension. For example, a display of 480x854 pixels would be 854 / 480 1694 = 1.779, or roughly "16:9".</li> 1695 <li>A "density-independent pixel" or ("dp") is the virtual pixel unit normalized to a 1696 160 dpi screen, calculated as: 1697 <code>pixels = dps * (density / 160)</code>.</li> 1698 </ul> 1699 1700 1701 <a name="section-7.1.1"></a><h4 id="section-7.1.1">7.1.1. Screen Configuration</h4> 1702 1703 <p style="font-weight:bold;">Screen Size</p> 1704 <p>The Android UI framework supports a variety of different screen sizes, and 1705 allows applications to query the device screen size (aka "screen layout") via 1706 <code>android.content.res.Configuration.screenLayout</code> with the 1707 <code>SCREENLAYOUT_SIZE_MASK</code>. Device implementations MUST report the 1708 correct screen size as defined in the Android SDK documentation 1709 [<a href="#resources38">Resources, 38</a>] and determined by the upstream 1710 Android platform. Specifically, device implementations must report the correct 1711 screen size according to the following logical density-independent pixel (dp) 1712 screen dimensions.</p> 1713 <ul> 1714 <li>Devices MUST have screen sizes of at least 426 dp x 320 dp ('small')</li> 1715 <li>Devices that report screen size 'normal' MUST have screen sizes of at least 1716 480 dp x 320 dp</li> 1717 <li>Devices that report screen size 'large' MUST have screen sizes of at least 1718 640 dp x 480 dp</li> 1719 <li>Devices that report screen size 'xlarge' MUST have screen sizes of at least 1720 960 dp x 720 dp</li> 1721 </ul> 1722 <p>In addition, devices MUST have screen sizes of at least 2.5 inches in 1723 physical diagonal size.</p> 1724 1725 <p>Devices MUST NOT change their reported screen size at any time.</p> 1726 <p>Applications optionally indicate which screen sizes they support via the 1727 <code><supports-screens></code> attribute in the AndroidManifest.xml 1728 file. Device implementations MUST correctly honor applications' stated support 1729 for small, normal, large, and xlarge screens, as described in the Android 1730 SDK documentation.</p> 1731 1732 <p style="font-weight:bold;">Screen Aspect Ratio</p> 1733 <p>The aspect ratio MUST be a value from 1.3333 (4:3) to 1.86 (roughly 16:9)</p> 1734 1735 <p style="font-weight:bold;">Screen Density</p> 1736 <p>The Android UI framework defines a set of standard logical densities to 1737 help application developers target application resources. Device 1738 implementations MUST report one of the following logical Android framework 1739 densities through the <code>android.util.DisplayMetrics</code> APIs, and MUST 1740 execute applications at this standard density. 1741 <ul> 1742 <li>120 dpi, known as 'ldpi'</li> 1743 <li>160 dpi, known as 'mdpi'</li> 1744 <li>213 dpi, known as 'tvdpi'</li> 1745 <li>240 dpi, known as 'hdpi'</li> 1746 <li>320 dpi, known as 'xhdpi'</li> 1747 <li>400 dpi, known as '400dpi'</li> 1748 <li>480 dpi, known as 'xxhdpi'</li> 1749 <li>640 dpi, known as 'xxxhdpi'</li> 1750 </ul> 1751 Device implementations SHOULD define the standard Android framework density 1752 that is numerically closest to the physical density of the screen, unless that 1753 logical density pushes the reported screen size below the minimum supported. 1754 If the standard Android framework density that is numerically closest to the 1755 physical density results in a screen size that is smaller than the smallest 1756 supported compatible screen size (320 dp width), device implementations SHOULD 1757 report the next lowest standard Android framework density.</p> 1758 1759 <a name="section-7.1.2"></a><h4 id="section-7.1.2">7.1.2. Display Metrics</h4> 1760 <p>Device implementations MUST report correct values for all display metrics 1761 defined in <code>android.util.DisplayMetrics</code> [<a 1762 href="#resources39">Resources, 39</a>].</p> 1763 1764 <a name="section-7.1.3"></a><h4 id="section-7.1.3">7.1.3. Screen Orientation</h4> 1765 <p>Devices MUST support dynamic orientation by applications to 1766 either portrait or landscape screen orientation. That is, the device must 1767 respect the application's request for a specific screen orientation. Device 1768 implementations MAY select either portrait or landscape orientation as the 1769 default.</p> 1770 <p>Devices MUST report the correct value for the device's current orientation, 1771 whenever queried via the android.content.res.Configuration.orientation, 1772 android.view.Display.getOrientation(), or other APIs.</p> 1773 <p>Devices MUST NOT change the reported screen size or density when changing 1774 orientation.</p> 1775 <p>Devices MUST report which screen orientations they support ( 1776 <code>android.hardware.screen.portrait</code> and/or 1777 <code>android.hardware.screen.landscape</code>) and MUST report at least one 1778 supported orientation. For example, a device with a fixed-orientation 1779 landscape screen, such as a television or laptop, MUST only report 1780 <code>android.hardware.screen.landscape</code>.</p> 1781 1782 <a name="section-7.1.4"></a><h4 id="section-7.1.4">7.1.4. 2D and 3D Graphics Acceleration</h4> 1783 <p>Device implementations MUST support both OpenGL ES 1.0 and 2.0, as embodied 1784 and detailed in the Android SDK documentations. Device implementations SHOULD support 1785 OpenGL ES 3.0 on devices capable of supporting OpenGL ES 3.0. 1786 Device implementations MUST also support Android Renderscript, as detailed in the Android SDK 1787 documentation [<a href="#resources08">Resources, 8</a>].</p> 1788 <p>Device implementations MUST also correctly identify themselves as 1789 supporting OpenGL ES 1.0, OpenGL ES 2.0, or OpenGL ES 3.0. That is:</p> 1790 <ul> 1791 <li>The managed APIs (such as via the <code>GLES10.getString()</code> method) 1792 MUST report support for OpenGL ES 1.0 and OpenGL ES 2.0 </li> 1793 <li>The native C/C++ OpenGL APIs (that is, those available to apps via 1794 libGLES_v1CM.so, libGLES_v2.so, or libEGL.so) MUST report support for 1795 OpenGL ES 1.0 and OpenGL ES 2.0.</li> 1796 <li>Device implementations that declare support for OpenGL ES 3.0 MUST support 1797 OpenGL ES 3.0 managed APIs and include support for native C/C++ APIs. On device 1798 implementations that declare support for OpenGL ES 3.0, libGLESv2.so MUST export the OpenGL ES 3.0 1799 function symbols in addition to the OpenGL ES 2.0 function symbols. 1800 </li> 1801 </ul> 1802 1803 <p>Device implementations MAY implement any desired OpenGL ES extensions. 1804 However, device implementations MUST report via the OpenGL ES managed and 1805 native APIs all extension strings that they do support, and conversely MUST 1806 NOT report extension strings that they do not support.</p> 1807 <p>Note that Android includes support for applications to optionally 1808 specify that they require specific OpenGL texture compression formats. These 1809 formats are typically vendor-specific. Device implementations are not required 1810 by Android to implement any specific texture compression format. However, 1811 they SHOULD accurately report any texture compression formats that they do 1812 support, via the <code>getString()</code> method in the OpenGL API.</p> 1813 1814 <p>Android includes a mechanism for applications to declare that they 1815 wanted to enable hardware acceleration for 2D graphics at the Application, 1816 Activity, Window or View level through the use of a manifest tag 1817 <code>android:hardwareAccelerated</code> or direct API calls 1818 [<a href="#resources09">Resources, 9</a>].</p> 1819 <p>In Android 4.4, device implementations MUST enable hardware acceleration by 1820 default, and MUST disable hardware acceleration if the developer so requests 1821 by setting <code>android:hardwareAccelerated="false"</code> or disabling 1822 hardware acceleration directly through the Android View APIs.</p> 1823 <p>In addition, device implementations MUST exhibit behavior consistent with the 1824 Android SDK documentation on hardware acceleration 1825 [<a href="#resources09">Resources, 9</a>].</p> 1826 <p>Android includes a <code>TextureView</code> object that lets developers 1827 directly integrate hardware-accelerated OpenGL ES textures as rendering targets 1828 in a UI hierarchy. Device implementations MUST support the <code>TextureView 1829 </code> API, and MUST exhibit consistent behavior with the upstream Android 1830 implementation.</p> 1831 <p>Android includes support for <code>EGL_ANDROID_RECORDABLE</code>, a EGLConfig attribute 1832 that indicates whether the EGLConfig supports rendering to an ANativeWindow that records images to a video. 1833 Device implementations MUST support <code>EGL_ANDROID_RECORDABLE</code> extension [<a href="#resources79">Resources, 79</a>].</p> 1834 1835 <a name="section-7.1.5"></a><h4 id="section-7.1.5">7.1.5. Legacy Application Compatibility Mode</h4> 1836 <p>Android specifies a "compatibility mode" in which the framework 1837 operates in an 'normal' screen size equivalent (320dp width) mode for the benefit 1838 of legacy applications not developed for old versions of Android that pre-date 1839 screen-size independence. Device implementations MUST include support for legacy 1840 application compatibility mode as implemented by the upstream Android open source 1841 code. That is, device implementations MUST NOT alter the triggers or thresholds at 1842 which compatibility mode is activated, and MUST NOT alter the behavior of the 1843 compatibility mode itself.</p> 1844 1845 <a name="section-7.1.6"></a><h4 id="section-7.1.6">7.1.6. Screen Types</h4> 1846 <p>Device implementation screens are classified as one of two types:</p> 1847 <ul> 1848 <li>Fixed-pixel display implementations: the screen is a single panel that supports only a 1849 single pixel width and height. Typically the screen is physically integrated with 1850 the device. Examples include mobile phones, tablets, and so on.</li> 1851 <li>Variable-pixel display implementations: the device implementation either has no 1852 embedded screen and includes a video output port such as VGA, HDMI or a wireless port 1853 for display, or has an embedded screen that can change pixel dimensions. Examples 1854 include televisions, set-top boxes, and so on.</li> 1855 </ul> 1856 <p style="font-weight: bold;">Fixed-Pixel Device Implementations</p> 1857 <p>Fixed-pixel device implementations MAY use screens of any pixel dimensions, provided 1858 that they meet the requirements defined this Compatibility Definition.</p> 1859 <p>Fixed-pixel implementations MAY include a video output port for use with an 1860 external display. However, if that display is ever used for running apps, the 1861 device MUST meet the following requirements:</p> 1862 <ul> 1863 <li>The device MUST report the same screen configuration and display metrics, as detailed 1864 in Sections 7.1.1 and 7.1.2, as the fixed-pixel display.</li> 1865 <li>The device MUST report the same logical density as the fixed-pixel display.</li> 1866 <li>The device MUST report screen dimensions that are the same as, or very close to, 1867 the fixed-pixel display.</li> 1868 </ul> 1869 <p>For example, a tablet that is 7" diagonal size with a 1024x600 pixel resolution is 1870 considered a fixed-pixel large mdpi display implementation. If it contains a video 1871 output port that displays at 720p or 1080p the device implementation MUST scale the output so that 1872 applications are only executed in a large mdpi window, regardless of whether the fixed-pixel display 1873 or video output port is in use.</p> 1874 1875 <p style="font-weight: bold;">Variable-Pixel Device Implementations</p> 1876 <p>Variable-pixel device implementations MUST support at least one of 1280x720, 1877 1920x1080, or 3840x2160 (that is, 720p, 1080p, or 4K). Device implementations with 1878 variable-pixel displays MUST NOT support any other screen configuration or 1879 mode. Device implementations with variable-pixel screens MAY change screen 1880 configuration or mode at runtime or boot-time. For example, a user of a 1881 set-top box may replace a 720p display with a 1080p display, and the device 1882 implementation may adjust accordingly.</p> 1883 1884 <p>Additionally, variable-pixel device implementations MUST report the following 1885 configuration buckets for these pixel dimensions:</p> 1886 <ul> 1887 <li>1280x720 (also known as 720p): 'large' screen size, 'tvdpi' (213 dpi) 1888 density</li> 1889 <li>1920x1080 (also known as 1080p): 'large' screen size, 'xhdpi' (320 dpi) 1890 density</li> 1891 <li>3840x2160 (also known as 4K): 'large' screen size, 'xxxhdpi' (640 dpi) 1892 density</li> 1893 </ul> 1894 <p>For clarity, device implementations with variable pixel dimensions are 1895 restricted to 720p, 1080p, or 4K in Android 4.4, and MUST be configured to report 1896 screen size and density buckets as noted above.</p> 1897 1898 <a name="section-7.1.7"></a><h4 id="section-7.1.7">7.1.7. Screen Technology</h4> 1899 <p>The Android platform includes APIs that allow applications to render rich 1900 graphics to the display. Devices MUST support all of these APIs as defined by 1901 the Android SDK unless specifically allowed in this document. Specifically:</p> 1902 <ul> 1903 <li>Devices MUST support displays capable of rendering 16-bit color graphics and 1904 SHOULD support displays capable of 24-bit color graphics.</li> 1905 <li>Devices MUST support displays capable of rendering animations.</li> 1906 <li>The display technology used MUST have a pixel aspect ratio (PAR) between 1907 0.9 and 1.1. That is, the pixel aspect ratio MUST be near square (1.0) with 1908 a 10% tolerance.</li> 1909 </ul> 1910 <a name="section-7.1.8"></a><h4 id="section-7.1.8">7.1.8. External Displays</h4> 1911 <p>Android includes support for secondary display to enable media sharing capabilities and 1912 developer APIs for accessing external displays. If a device supports an external display either via 1913 a wired, wireless or an embedded additional display connection then the device implementation MUST 1914 implement the display manager API as described in the Android SDK documentation [<a href="#resources75">Resources, 75</a>]. 1915 Device implementations that support secure video output and are capable of supporting secure surfaces MUST declare support 1916 for <code>Display.FLAG_SECURE</code>. Specifically, device implementations that declare support for <code>Display.FLAG_SECURE</code>, 1917 MUST support <b>HDCP 2.x or higher</b> for Miracast wireless displays or <b>HDCP 1.2 or higher</b> for wired displays. The upstream 1918 Android open source implementation includes support for wireless (Miracast) and wired (HDMI) displays that satisfies this requirement.</p> 1919 1920 <a name="section-7.2"></a><h3 id="section-7.2">7.2. Input Devices</h3> 1921 <a name="section-7.2.1"></a><h4 id="section-7.2.1">7.2.1. Keyboard</h4> 1922 <p>Device implementations:</p> 1923 <ul> 1924 <li>MUST include support for the Input Management Framework (which allows third 1925 party developers to create Input Management Engines - i.e. soft keyboard) as 1926 detailed at <a href="http://developer.android.com">http://developer.android.com</a> 1927 </li> 1928 <li>MUST provide at least one soft keyboard implementation (regardless of whether 1929 a hard keyboard is present)</li> 1930 <li>MAY include additional soft keyboard implementations</li> 1931 <li>MAY include a hardware keyboard</li> 1932 <li>MUST NOT include a hardware keyboard that does not match one of the 1933 formats specified in <code>android.content.res.Configuration.keyboard</code> 1934 [<a href="#resources40">Resources, 40</a>] (that is, QWERTY, or 12-key)</li> 1935 </ul> 1936 <a name="section-7.2.2"></a><h4 id="section-7.2.2">7.2.2. Non-touch Navigation</h4> 1937 <p>Device implementations:</p> 1938 <ul> 1939 <li>MAY omit a non-touch navigation option (that is, may omit a trackball, d-pad, 1940 or wheel)</li> 1941 <li>MUST report the correct value for 1942 <code>android.content.res.Configuration.navigation</code> 1943 [<a href="#resources40">Resources, 40</a>]</li> 1944 <li>MUST provide a reasonable alternative user interface mechanism for the 1945 selection and editing of text, compatible with Input Management Engines. The 1946 upstream Android open source implementation includes a selection mechanism suitable 1947 for use with devices that lack non-touch navigation inputs.</li> 1948 </ul> 1949 <a name="section-7.2.3"></a><h4 id="section-7.2.3">7.2.3. Navigation keys</h4> 1950 <p>The Home, Recents and Back functions are essential to the Android navigation 1951 paradigm. Device implementations MUST make these functions available to the user 1952 at all times when running applications. These functions MAY be implemented via 1953 dedicated physical buttons (such as mechanical or capacitive touch buttons), or 1954 MAY be implemented using dedicated software keys on a distinct portion of the 1955 screen, gestures, touch panel, etc. Android supports both implementations. All 1956 of these functions MUST be accessible with a single action (e.g. tap, 1957 double-click or gesture) when visible.</p> 1958 <p>The Back and Recents functions SHOULD have a visible button or icon unless 1959 hidden together with other navigation functions in full-screen mode. The Home 1960 function MUST have a visible button or icon unless hidden together with other 1961 navigation functions in full-screen mode.</p> 1962 <p>The Menu function is deprecated in favor of action bar since Android 4.0. 1963 Device implementations SHOULD NOT implement a dedicated physical button for 1964 the Menu function. If the physical Menu button is implemented and the device 1965 is running applications with <code>targetSdkVersion</code> > 10, the device 1966 implementation:</p> 1967 <ul> 1968 <li>for a device launching with Android 4.4, MUST display the action overflow 1969 button on the action bar when the action bar is visible and the resulting action 1970 overflow menu popu is not empty.</li> 1971 <li>for an existing device launched with an earlier version but upgrading to 1972 Android 4.4, SHOULD display the action overflow button on the action bar 1973 when the action bar is visible and the resulting action overflow menu popup 1974 is not empty.</li> 1975 <li>MUST NOT modify the position of the action overflow popup displayed by 1976 selecting the overflow button in the action bar.</li> 1977 <li>MAY render the action overflow popup at a modified position on the screen 1978 when it is displayed by selecting the physical menu button.</li> 1979 </ul> 1980 <p>For backwards compatibility, device implementations MUST make available the 1981 Menu function to applications when <code>targetSdkVersion</code> <= 10, 1982 either by a phsyical button, a software key or gestures. This Menu function 1983 should be presented unless hidden together with other navigation functions.</p> 1984 <p>Android supports Assist action [<a href="#resources63">Resources, 63</a>]. 1985 Device implementations MUST make the Assist action available to the user at all 1986 times when running applications. The Assist action SHOULD be implemented as a 1987 long-press on the Home button or a swipe-up gesture on the software Home key. 1988 This function MAY be implemented via another physical button, software key or 1989 gestures, but MUST be accessible with a single action (e.g. tap, double-click or 1990 gesture) when other navigation keys are visible.</p> 1991 <p>Device implementations MAY use a distinct portion of the screen to display 1992 the navigation keys, but if so, MUST meet these requirements:</p> 1993 <ul> 1994 <li>Device implementation navigation keys MUST use a distinct portion of the 1995 screen, not available to applications, and MUST NOT obscure or otherwise 1996 interfere with the portion of the screen available to applications.</li> 1997 <li>Device implementations MUST make available a portion of the display to 1998 applications that meets the requirements defined in 1999 <a href="section-7.1.1">Section 7.1.1</a>.</li> 2000 <li>Device implementations MUST display the navigation keys when applications 2001 do not specify a system UI mode, or specify 2002 <code>SYSTEM_UI_FLAG_VISIBLE</code>.</li> 2003 <li>Device implementations MUST present the navigation keys in an unobtrusive 2004 "low profile" (eg. dimmed) mode when applications specify 2005 <code>SYSTEM_UI_FLAG_LOW_PROFILE</code>.</li> 2006 <li>Device implementations MUST hide the navigation keys when applications 2007 specify <code>SYSTEM_UI_FLAG_HIDE_NAVIGATION</code>.</li> 2008 </ul> 2009 <a name="section-7.2.4"></a><h4 id="section-7.2.4">7.2.4. Touchscreen input</h4> 2010 <p>Device implementations SHOULD have a pointer input system of some kind (either mouse-like, or touch). However, if a device 2011 implementation does not support a pointer input system, it MUST NOT report the <code>android.hardware.touchscreen</code> or 2012 <code>android.hardware.faketouch</code> feature constant. Device implementations that do include a pointer input system:</p> 2013 <ul> 2014 <li>SHOULD support fully independently tracked pointers, if the device input system supports multiple pointers</li> 2015 <li>MUST report the value of <code>android.content.res.Configuration.touchscreen</code> [<a href="#resources40">Resources, 40</a>] 2016 corresponding to the type of the specific touchscreen on the device</li> 2017 </ul> 2018 2019 <p>Android includes support for a variety of touch screens, touch pads, and fake touch input devices. 2020 Touch screen based device implementations are associated with a display [<a href="#resources81">Resources, 81</a>] 2021 such that the user has the impression of directly manipulating items on screen. Since the user is directly touching the screen, 2022 the system does not require any additional affordances to indicate the objects being manipulated. 2023 In contrast, a fake touch interface provides a user input system that approximates a subset of touchscreen capabilities. 2024 For example, a mouse or remote control that drives an on-screen cursor approximates touch, but requires the user to first 2025 point or focus then click. Numerous input devices like the mouse, trackpad, gyro-based air mouse, gyro-pointer, joystick, 2026 and multi-touch trackpad can support fake touch interactions. Android 4.0 includes the feature constant <code>android.hardware.faketouch</code>, 2027 which corresponds to a high-fidelity non-touch (that is, pointer-based) input device such as a mouse or trackpad that can adequately emulate touch-based 2028 input (including basic gesture support), and indicates that the device supports an emulated subset of touchscreen 2029 functionality. Device implementations that declare the fake touch feature MUST meet the fake touch requirements in <a href="section 7.2.5">Section 7.2.5</a>.</p> 2030 2031 <p>Device implementations MUST report the correct feature corresponding to the type of input used. Device implementations that 2032 include a touchscreen (single-touch or better) MUST report the platform feature constant <code>android.hardware.touchscreen</code>. 2033 Device implementations that report the platform feature constant <code>android.hardware.touchscreen</code> MUST also report the platform feature constant 2034 <code>android.hardware.faketouch</code>. Device implementations that do not include a touchscreen (and rely on a pointer device only) MUST NOT report any 2035 touchscreen feature, and MUST report only <code>android.hardware.faketouch</code> if they meet the fake touch requirements in <a href="section 7.2.5">Section 7.2.5</a>.</p> 2036 2037 <a name="section-7.2.5"></a><h4 id="section-7.2.5">7.2.5. Fake touch input</h4> 2038 <p>Device implementations that declare support for <code>android.hardware.faketouch</code></p> 2039 <ul> 2040 <li> MUST report the absolute X and Y screen positions of the pointer location and display a visual pointer on the screen [<a href="#resources80">Resources, 80</a>] </li> 2041 <li> MUST report touch event with the action code [<a href="#resources80">Resources, 80</a>] that specifies the state change 2042 that occurs on the pointer going <code>down</code> or <code>up</code> on the screen [<a href="#resources80">Resources, 80</a>] </li> 2043 <li> MUST support pointer <code>down</code> and <code>up</code> on an object on the screen, which allows users to emulate tap on an object on the screen</li> 2044 <li> MUST support pointer <code>down</code>, pointer <code>up</code>, pointer <code>down</code> then pointer <code>up</code> in the same place on an object on the screen 2045 within a time threshold, which allows users to emulate double tap on an object on the screen [<a href="#resources80">Resources, 80</a>]</li> 2046 <li>MUST support pointer <code>down</code> on an arbitrary point on the screen, pointer move to any other arbitrary point on the screen, 2047 followed by a pointer <code>up</code>, which allows users to emulate a touch drag</li> 2048 <li> MUST support pointer <code>down</code> then allow users to quickly move the object to a different position on the screen 2049 and then pointer <code>up</code> on the screen, which allows users to fling an object on the screen</li> 2050 </ul> 2051 2052 <p>Devices that declare support for <code>android.hardware.faketouch.multitouch.distinct</code> MUST meet the requirements for 2053 faketouch above, and MUST also support distinct tracking of two or more independent pointer inputs.</p> 2054 2055 <a name="section-7.2.6"></a><h4 id="section-7.2.6">7.2.6. Microphone</h4> 2056 <p>Device implementations MAY omit a microphone. However, if a device 2057 implementation omits a microphone, it MUST NOT report the 2058 <code>android.hardware.microphone</code> feature constant, and must implement 2059 the audio recording API as no-ops, per <a href="section-7">Section 7</a>. 2060 Conversely, device implementations that do possess a microphone:</p> 2061 <ul> 2062 <li>MUST report the <code>android.hardware.microphone</code> feature constant</li> 2063 <li>SHOULD meet the audio quality requirements in <a href="section-5.4">Section 5.4</a></li> 2064 <li>SHOULD meet the audio latency requirements in <a href="section-5.5">Section 5.5</a></li> 2065 </ul> 2066 2067 <a name="section-7.3"></a><h3 id="section-7.3">7.3. Sensors</h3> 2068 <p>Android includes APIs for accessing a variety of sensor types. Devices 2069 implementations generally MAY omit these sensors, as provided for in the 2070 following subsections. If a device includes a particular sensor type that has a 2071 corresponding API for third-party developers, the device implementation MUST 2072 implement that API as described in the Android SDK documentation. For example, 2073 device implementations:</p> 2074 <ul> 2075 <li>MUST accurately report the presence or absence of sensors per the 2076 <code>android.content.pm.PackageManager</code> class. [<a 2077 href="#resources37">Resources, 37</a>]</li> 2078 <li>MUST return an accurate list of supported sensors via the 2079 <code>SensorManager.getSensorList()</code> and similar methods</li> 2080 <li>MUST behave reasonably for all other sensor APIs (for example, by 2081 returning true or false as appropriate when applications attempt to register 2082 listeners, not calling sensor listeners when the corresponding sensors are not 2083 present; etc.)</li> 2084 <li>MUST report all sensor measurements using the relevant International System 2085 of Units (i.e. metric) values for each sensor type as defined in the Android SDK 2086 documentation [<a href="#resources41">Resources, 41</a>]</li> 2087 </ul> 2088 <p>The list above is not comprehensive; the documented behavior of the Android 2089 SDK is to be considered authoritative.</p> 2090 <p>Some sensor types are synthetic, meaning they can be derived from data 2091 provided by one or more other sensors. (Examples include the orientation 2092 sensor, and the linear acceleration sensor.) Device implementations SHOULD 2093 implement these sensor types, when they include the prerequisite physical 2094 sensors.</p> 2095 <p>Android includes a notion of a "streaming" sensor, which is 2096 one that returns data continuously, rather than only when the data changes. 2097 Device implementations MUST continuously provide periodic data samples for any 2098 API indicated by the Android SDK documentation to be a streaming 2099 sensor. Note that the device implementations MUST ensure that the sensor stream must not 2100 prevent the device CPU from entering a suspend state or waking up from a suspend state.</p> 2101 2102 <a name="section-7.3.1"></a><h4 id="section-7.3.1">7.3.1. Accelerometer</h4> 2103 <p>Device implementations SHOULD include a 3-axis accelerometer. If a device 2104 implementation does include a 3-axis accelerometer, it:</p> 2105 <ul> 2106 <li>SHOULD be able to deliver events at 120 Hz or greater. Note that while the 2107 accelerometer frequency above is stated as "SHOULD" for Android 4.4, the Compatibility Definition 2108 for a future version is planned to change these to "MUST". That is, these standards are 2109 optional in Android but <b>will be required</b> in future versions. Existing and 2110 new devices that run Android are <b>very strongly encouraged to meet these requirements 2111 in Android</b> so they will be able to upgrade to the future platform releases 2112 </li> 2113 <li>MUST comply with the Android sensor coordinate system as detailed 2114 in the Android APIs (see [<a href="#resources41">Resources, 41</a>])</li> 2115 <li>MUST be capable of measuring from freefall up to twice gravity (2g) or 2116 more on any three-dimensional vector</li> 2117 <li>MUST have 8-bits of accuracy or more</li> 2118 <li>MUST have a standard deviation no greater than 0.05 m/s^2</li> 2119 </ul> 2120 <a name="section-7.3.2"></a><h4 id="section-7.3.2">7.3.2. Magnetometer</h4> 2121 <p>Device implementations SHOULD include a 3-axis magnetometer (i.e. compass.) 2122 If a device does include a 3-axis magnetometer, it:</p> 2123 <ul> 2124 <li>MUST be able to deliver events at 10 Hz or greater</li> 2125 <li>MUST comply with the Android sensor coordinate system as detailed 2126 in the Android APIs (see [<a href="#resources41">Resources, 41</a>]).</li> 2127 <li>MUST be capable of sampling a range of field strengths adequate to cover the 2128 geomagnetic field</li> 2129 <li>MUST have 8-bits of accuracy or more</li> 2130 <li>MUST have a standard deviation no greater than 0.5 µT</li> 2131 </ul> 2132 <a name="section-7.3.3"></a><h4 id="section-7.3.3">7.3.3. GPS</h4> 2133 <p>Device implementations SHOULD include a GPS receiver. If a device 2134 implementation does include a GPS receiver, it SHOULD include 2135 some form of "assisted GPS" technique to minimize GPS lock-on time.</p> 2136 <a name="section-7.3.4"></a><h4 id="section-7.3.4">7.3.4. Gyroscope</h4> 2137 <p>Device implementations SHOULD include a gyroscope (i.e. angular change 2138 sensor.) Devices SHOULD NOT include a gyroscope sensor unless a 3-axis 2139 accelerometer is also included. If a device implementation includes a 2140 gyroscope, it:</p> 2141 <ul> 2142 <li>MUST be temperature compensated.</li> 2143 <li>MUST be capable of measuring orientation changes up to 5.5*Pi 2144 radians/second (that is, approximately 1,000 degrees per second).</li> 2145 <li>SHOULD be able to deliver events at 200 Hz or greater. Note that while the 2146 gyroscope frequency above is stated as "SHOULD" for Android 4.4, the Compatibility Definition 2147 for a future version is planned to change these to "MUST". That is, these standards are 2148 optional in Android but <b>will be required</b> in future versions. Existing and 2149 new devices that run Android are <b>very strongly encouraged to meet these requirements</b> 2150 so they will be able to upgrade to the future platform releases. 2151 </li> 2152 <li>MUST have 12-bits of accuracy or more</li> 2153 <li>MUST have a variance no greater than 1e-7 rad^2 / s^2 per Hz (variance per Hz, or rad^2 / s). 2154 The variance is allowed to vary with the sampling rate, but must be constrained by this value. 2155 In other words, if you measure the variance of the gyro at 1 Hz sampling rate it should be no 2156 greater than 1e-7 rad^2/s^2.</li> 2157 <li>MUST have timestamps as close to when the hardware event happened as possible. The constant latency must be removed.</li> 2158 </ul> 2159 <a name="section-7.3.5"></a><h4 id="section-7.3.5">7.3.5. Barometer</h4> 2160 <p>Device implementations MAY include a barometer (i.e. ambient air pressure 2161 sensor.) If a device implementation includes a barometer, it:</p> 2162 <ul> 2163 <li>MUST be able to deliver events at 5 Hz or greater</li> 2164 <li>MUST have adequate precision to enable estimating altitude</li> 2165 <li>MUST be temperature compensated</li> 2166 </ul> 2167 <a name="section-7.3.6"></a><h4 id="section-7.3.6">7.3.6. Thermometer</h4> 2168 <p>Device implementations MAY include an ambient thermometer (i.e. temperature 2169 sensor). If present, it MUST be defined as <code>SENSOR_TYPE_AMBIENT_TEMPERATURE</code> 2170 and it MUST measure the ambient (room) temperature in degrees Celsius.</p> 2171 2172 <p>Device implementations MAY but SHOULD NOT include a CPU temperature sensor. 2173 If present, it MUST be defined as <code>SENSOR_TYPE_TEMPERATURE</code>, it MUST 2174 measure the temperature of the device CPU, and it MUST NOT measure any other 2175 temperature. Note the <code>SENSOR_TYPE_TEMPERATURE</code> sensor type was 2176 deprecated in Android 4.0.</p> 2177 <a name="section-7.3.7"></a><h4 id="section-7.3.7">7.3.7. Photometer</h4> 2178 <p>Device implementations MAY include a photometer (i.e. ambient light 2179 sensor.)</p> 2180 <a name="section-7.3.8"></a><h4 id="section-7.3.8">7.3.8. Proximity Sensor</h4> 2181 <p>Device implementations MAY include a proximity sensor. If a device 2182 implementation does include a proximity sensor, it MUST measure the proximity 2183 of an object in the same direction as the screen. That is, the proximity 2184 sensor MUST be oriented to detect objects close to the screen, as the 2185 primary intent of this sensor type is to detect a phone in use by the 2186 user. If a device implementation includes a proximity sensor with any other 2187 orientation, it MUST NOT be accessible through this API. If a device 2188 implementation has a proximity sensor, it MUST be have 1-bit of accuracy or 2189 more.</p> 2190 2191 <a name="section-7.4"></a><h3 id="section-7.4">7.4. Data Connectivity</h3> 2192 <a name="section-7.4.1"></a><h4 id="section-7.4.1">7.4.1. Telephony</h4> 2193 <p>"Telephony" as used by the Android APIs and this document refers 2194 specifically to hardware related to placing voice calls and sending SMS 2195 messages via a GSM or CDMA network. While these voice calls may or may not be 2196 packet-switched, they are for the purposes of Android considered 2197 independent of any data connectivity that may be implemented using the same 2198 network. In other words, the Android "telephony" functionality and APIs refer 2199 specifically to voice calls and SMS; for instance, device implementations that 2200 cannot place calls or send/receive SMS messages MUST NOT report the 2201 "android.hardware.telephony" feature or any sub-features, regardless of 2202 whether they use a cellular network for data connectivity.</p> 2203 <p>Android MAY be used on devices that do not include telephony hardware. 2204 That is, Android is compatible with devices that are not phones. 2205 However, if a device implementation does include GSM or CDMA telephony, it 2206 MUST implement full support for the API for that technology. Device 2207 implementations that do not include telephony hardware MUST implement the full 2208 APIs as no-ops.</p> 2209 <a name="section-7.4.2"></a><h4 id="section-7.4.2">7.4.2. IEEE 802.11 (Wi-Fi)</h4> 2210 <p>Android device implementations SHOULD include support for one or more 2211 forms of 802.11 (b/g/a/n, etc.) If a device implementation does include 2212 support for 802.11, it MUST implement the corresponding Android API.</p> 2213 <p>Device implementations MUST implement the multicast API as described in 2214 the SDK documentation [<a href="#resources62">Resources, 62</a>]. Device 2215 implementations that do include Wi-Fi support MUST support multicast DNS (mDNS). 2216 Device implementations MUST NOT filter mDNS packets (224.0.0.251) at any time 2217 of operation including when the screen is not in an active state.</p> 2218 2219 <a name="section-7.4.2.1"></a> 2220 <h4 id="section-7.4.2.1">7.4.2.1. Wi-Fi Direct</h4> 2221 <p>Device implementations SHOULD include support for Wi-Fi direct (Wi-Fi peer-to-peer). 2222 If a device implementation does include support for Wi-Fi direct, it MUST implement the corresponding 2223 Android API as described in the SDK documentation [<a href="#resources68">Resources, 68</a>]. 2224 If a device implementation includes support for Wi-Fi direct, then it:</p> 2225 <ul> 2226 <li>MUST support regular Wi-Fi operation</li> 2227 <li>SHOULD support concurrent Wi-Fi and Wi-Fi Direct operation</li> 2228 </ul> 2229 2230 <a name="section-7.4.2.2"></a><h4 id="section-7.4.2.2">7.4.2.2. Wi-Fi Tunneled Direct Link Setup</h4> 2231 <p>Device implementations SHOULD include support for Wi-Fi Tunneled Direct Link 2232 Setup (TDLS) as described in the Android SDK Documentation 2233 [<a href="#resources85">Resources, 85</a>]. If a device implementation does 2234 include support for TDLS and TDLS is enabled by the WiFiManager API, the device: 2235 </p> 2236 <ul> 2237 <li>SHOULD use TDLS only when it is possible AND beneficial.</li> 2238 <li>SHOULD have some heuristic and NOT use TDLS when its performance might be 2239 worse than going through the Wi-Fi access point.</li> 2240 </ul> 2241 2242 <a name="section-7.4.3"></a><h4 id="section-7.4.3">7.4.3. Bluetooth</h4> 2243 <p>Device implementations SHOULD include a Bluetooth transceiver. Device 2244 implementations that do include a Bluetooth transceiver MUST enable the 2245 RFCOMM-based Bluetooth API as described in the SDK documentation and declare 2246 hardware feature android.hardware.bluetooth [<a href="#resources42">Resources, 42</a>]. 2247 Device implementations SHOULD implement relevant Bluetooth profiles, such as A2DP, AVRCP, OBEX, etc. as 2248 appropriate for the device.</p> 2249 2250 <p>Device implementations that do include support for Bluetooth GATT (generic attribute profile) 2251 to enable communication with Bluetooth Smart or Smart Ready devices MUST enable the 2252 GATT-based Bluetooth API as described in the SDK documentation and declare hardware feature 2253 android.hardware.bluetooth_le [<a href="#resources42">Resources, 42</a>].</p> 2254 2255 <a name="section-7.4.4"></a><h4 id="section-7.4.4">7.4.4. Near-Field Communications</h4> 2256 <p>Device implementations SHOULD include a transceiver and related hardware 2257 for Near-Field Communications (NFC). If a device implementation does include 2258 NFC hardware, then it:</p> 2259 <ul> 2260 <li>MUST report the android.hardware.nfc feature from the 2261 <code>android.content.pm.PackageManager.hasSystemFeature()</code> method. 2262 [<a href="#resources37">Resources, 37</a>]</li> 2263 <li>MUST be capable of reading and writing NDEF messages via the following NFC 2264 standards: 2265 <ul> 2266 <li>MUST be capable of acting as an NFC Forum reader/writer 2267 (as defined by the NFC Forum technical specification 2268 NFCForum-TS-DigitalProtocol-1.0) via the following NFC standards: 2269 <ul> 2270 <li>NfcA (ISO14443-3A)</li> 2271 <li>NfcB (ISO14443-3B) </li> 2272 <li>NfcF (JIS 6319-4)</li> 2273 <li>IsoDep (ISO 14443-4)</li> 2274 <li>NFC Forum Tag Types 1, 2, 3, 4 (defined by the NFC Forum)</li> 2275 </ul> 2276 </li> 2277 </ul> 2278 </li> 2279 <li>SHOULD be capable of reading and writing NDEF messages via the following 2280 NFC standards. Note that while the NFC standards below are stated as 2281 "SHOULD", the Compatibility Definition for a future version is planned to 2282 change these to "MUST". That is, these standards are optional in this 2283 version but <b>will be required</b> in future versions. Existing and new 2284 devices that run this version of Android are <b>very strongly encouraged 2285 to meet these requirements now</b> so they will be able to upgrade to the 2286 future platform releases. 2287 <ul> 2288 <li>NfcV (ISO 15693)</li> 2289 </ul> 2290 </li> 2291 <li>MUST be capable of transmitting and receiving data via the following 2292 peer-to-peer standards and protocols: 2293 <ul> 2294 <li>ISO 18092</li> 2295 <li>LLCP 1.0 (defined by the NFC Forum)</li> 2296 <li>SDP 1.0 (defined by the NFC Forum)</li> 2297 <li>NDEF Push Protocol [<a href="#resources43">Resources, 43</a>]</li> 2298 <li>SNEP 1.0 (defined by the NFC Forum)</li> 2299 </ul> 2300 </li> 2301 <li>MUST include support for Android Beam [<a href="#resources65">Resources, 65</a>]: 2302 <ul> 2303 <li>MUST implement the SNEP default server. Valid NDEF messages received 2304 by the default SNEP server MUST be dispatched to applications using 2305 the android.nfc.ACTION_NDEF_DISCOVERED intent. Disabling Android Beam 2306 in settings MUST NOT disable dispatch of incoming NDEF message.</li> 2307 <li>Device implementations MUST honor the android.settings.NFCSHARING_SETTINGS intent 2308 to show NFC sharing settings [<a href="#resources67">Resources, 67</a>].</li> 2309 <li>MUST implement the NPP server. Messages received by the NPP server MUST 2310 be processed the same way as the SNEP default server.</li> 2311 <li>MUST implement a SNEP client and attempt to send outbound P2P NDEF to 2312 the default SNEP server when Android Beam is enabled. If no default 2313 SNEP server is found then the client MUST attempt to send to an NPP 2314 server.</li> 2315 <li>MUST allow foreground activities to set the outbound P2P NDEF message 2316 using android.nfc.NfcAdapter.setNdefPushMessage, and 2317 android.nfc.NfcAdapter.setNdefPushMessageCallback, and 2318 android.nfc.NfcAdapter.enableForegroundNdefPush.</li> 2319 <li>SHOULD use a gesture or on-screen confirmation, such as 'Touch to Beam', 2320 before sending outbound P2P NDEF messages.</li> 2321 <li>SHOULD enable Android Beam by default</li> 2322 <li>MUST support NFC Connection handover to Bluetooth when the device supports Bluetooth Object Push Profile. 2323 Device implementations must support connection handover to Bluetooth when using android.nfc.NfcAdapter.setBeamPushUris, 2324 by implementing the "Connection Handover version 1.2" [<a href="#resources60">Resources, 60</a>] 2325 and "Bluetooth Secure Simple Pairing Using NFC version 1.0" [<a href="#resources61">Resources, 61</a>] 2326 specs from the NFC Forum. Such an implementation MUST implement the 2327 handover LLCP service with service name "urn:nfc:sn:handover" for 2328 exchanging the handover request/select records over NFC, and it MUST use 2329 the Bluetooth Object Push Profile for the actual Bluetooth data 2330 transfer. For legacy reasons (to remain compatible with Android 4.1 2331 devices), the implementation SHOULD still accept SNEP GET requests for 2332 exchanging the handover request/select records over NFC. However an 2333 implementation itself SHOULD NOT send SNEP GET requests for performing 2334 connection handover.</li> 2335 </ul> 2336 </li> 2337 <li>MUST poll for all supported technologies while in NFC discovery mode.</li> 2338 <li>SHOULD be in NFC discovery mode while the device is awake with the screen active 2339 and the lock-screen unlocked.</li> 2340 </ul> 2341 2342 <p>(Note that publicly available links are not available for the JIS, ISO, and 2343 NFC Forum specifications cited above.)</p> 2344 <p>Android 4.4 introduces support for NFC Host Card Emulation (HCE) mode. If a 2345 device implementation does include an NFC controller capable of HCE and 2346 Application ID (AID) routing, then it:</p> 2347 <ul> 2348 <li>MUST report the <code>android.hardware.nfc.hce</code> feature constant 2349 </li> 2350 <li>MUST support NFC HCE APIs as defined in the Android SDK 2351 [<a href="#resources90">Resources, 90</a>]</li> 2352 </ul> 2353 <p>Additionally, device implementations MAY include reader/writer support for 2354 the following MIFARE technologies.</p> 2355 <ul> 2356 <li>MIFARE Classic (NXP MF1S503x [<a href="#resources44">Resources, 44</a>], 2357 MF1S703x [<a href="#resources45">Resources, 45</a>])</li> 2358 <li>MIFARE Ultralight (NXP MF0ICU1 [<a href="#resources46">Resources, 46</a>], 2359 MF0ICU2 [<a href="#resources47">Resources, 47</a>])</li> 2360 <li>NDEF on MIFARE Classic (NXP AN130511 [<a href="#resources48">Resources, 48</a>], 2361 AN130411 [<a href="#resources49">Resources, 49</a>])</li> 2362 </ul> 2363 <p>Note that Android includes APIs for these MIFARE types. If a 2364 device implementation supports MIFARE in the reader/writer role, it:</p> 2365 <ul> 2366 <li>MUST implement the corresponding Android APIs as documented by the 2367 Android SDK</li> 2368 <li>MUST report the feature com.nxp.mifare from the 2369 <code>android.content.pm.PackageManager.hasSystemFeature()</code> method. 2370 [<a href="#resources37">Resources, 37</a>] Note that this is not a standard 2371 Android feature, and as such does not appear as a constant on the 2372 <code>PackageManager</code> class.</li> 2373 <li>MUST NOT implement the corresponding Android APIs nor report the 2374 com.nxp.mifare feature unless it also implements general NFC support as 2375 described in this section</li> 2376 </ul> 2377 <p>If a device implementation does not include NFC hardware, it MUST NOT 2378 declare the android.hardware.nfc feature from the 2379 <code>android.content.pm.PackageManager.hasSystemFeature()</code> method [<a 2380 href="#resources37">Resources, 37</a>], and MUST implement the Android NFC 2381 API as a no-op.</p> 2382 <p>As the classes <code>android.nfc.NdefMessage</code> and 2383 <code>android.nfc.NdefRecord</code> represent a protocol-independent data 2384 representation format, device implementations MUST implement these APIs even 2385 if they do not include support for NFC or declare the android.hardware.nfc 2386 feature.</p> 2387 <a name="section-7.4.5"></a><h4 id="section-7.4.5">7.4.5. Minimum Network Capability</h4> 2388 <p>Device implementations MUST include support for one or more forms of data 2389 networking. Specifically, device implementations MUST include support for at 2390 least one data standard capable of 200Kbit/sec or greater. Examples of 2391 technologies that satisfy this requirement include EDGE, HSPA, EV-DO, 802.11g, 2392 Ethernet, etc.</p> 2393 <p>Device implementations where a physical networking standard (such as 2394 Ethernet) is the primary data connection SHOULD also include support for at 2395 least one common wireless data standard, such as 802.11 (Wi-Fi).</p> 2396 <p>Devices MAY implement more than one form of data connectivity.</p> 2397 2398 <a name="section-7.4.6"></a><h4 id="section-7.4.6">7.4.6. Sync Settings</h4> 2399 <p>Device implementations MUST have the master auto-sync setting on by default 2400 so that the method <code>getMasterSyncAutomatically()</code> returns 2401 "true" [<a href="#resources88">Resources, 88</a>].</p> 2402 2403 <a name="section-7.5"></a><h3 id="section-7.5">7.5. Cameras</h3> 2404 <p>Device implementations SHOULD include a rear-facing camera, and MAY include 2405 a front-facing camera. A rear-facing camera is a camera located on the side of 2406 the device opposite the display; that is, it images scenes on the far side of 2407 the device, like a traditional camera. A front-facing camera is a camera 2408 located on the same side of the device as the display; that is, a camera 2409 typically used to image the user, such as for video conferencing and similar 2410 applications.</p> 2411 <a name="section-7.5.1"></a><h4 id="section-7.5.1">7.5.1. Rear-Facing Camera</h4> 2412 <p>Device implementations SHOULD include a rear-facing camera. If a device 2413 implementation includes a rear-facing camera, it:</p> 2414 <ul> 2415 <li>MUST have a resolution of at least 2 megapixels</li> 2416 <li>SHOULD have either hardware auto-focus, or software auto-focus implemented 2417 in the camera driver (transparent to application software)</li> 2418 <li>MAY have fixed-focus or EDOF (extended depth of field) hardware</li> 2419 <li>MAY include a flash. If the Camera includes a flash, the flash lamp MUST 2420 NOT be lit while an android.hardware.Camera.PreviewCallback instance has been 2421 registered on a Camera preview surface, unless the application has explicitly 2422 enabled the flash by enabling the <code>FLASH_MODE_AUTO</code> or 2423 <code>FLASH_MODE_ON</code> attributes of a <code>Camera.Parameters</code> 2424 object. Note that this constraint does not apply to the device's built-in 2425 system camera application, but only to third-party applications using 2426 <code>Camera.PreviewCallback</code>.</li> 2427 </ul> 2428 <a name="section-7.5.2"></a><h4 id="section-7.5.2">7.5.2. Front-Facing Camera</h4> 2429 <p>Device implementations MAY include a front-facing camera. If a device 2430 implementation includes a front-facing camera, it:</p> 2431 <ul> 2432 <li>MUST have a resolution of at least VGA (that is, 640x480 pixels)</li> 2433 <li>MUST NOT use a front-facing camera as the default for the Camera API. 2434 That is, the camera API in Android has specific support for front-facing 2435 cameras, and device implementations MUST NOT configure the API to to treat a 2436 front-facing camera as the default rear-facing camera, even if it is the only 2437 camera on the device.</li> 2438 <li>MAY include features (such as auto-focus, flash, etc.) 2439 available to rear-facing cameras as described in Section 7.5.1.</li> 2440 <li>MUST horizontally reflect (i.e. mirror) the stream displayed by an app in a 2441 CameraPreview, as follows:</li> 2442 <ul> 2443 <li>If the device implementation is capable of being rotated by user (such as 2444 automatically via an accelerometer or manually via user input), the camera 2445 preview MUST be mirrored horizontally relative to the device's current 2446 orientation.</li> 2447 <li>If the current application has explicitly requested that the Camera 2448 display be rotated via a call to the 2449 <code>android.hardware.Camera.setDisplayOrientation()</code> [<a 2450 href="#resources50">Resources, 50</a>] method, the camera preview MUST be 2451 mirrored horizontally relative to the orientation specified by the 2452 application.</li> 2453 <li>Otherwise, the preview MUST be mirrored along the device's default horizontal axis.</li> 2454 </ul> 2455 <li>MUST mirror the image displayed by the postview in the same manner as 2456 the camera preview image stream. (If the device implementation does not 2457 support postview, this requirement obviously does not apply.)</li> 2458 <li>MUST NOT mirror the final captured still image or video streams returned 2459 to application callbacks or committed to media storage</li> 2460 </ul> 2461 <a name="section-7.5.3"></a><h4 id="section-7.5.3">7.5.3. Camera API Behavior</h4> 2462 <p>Device implementations MUST implement the following behaviors for the 2463 camera-related APIs, for both front- and rear-facing cameras:</p> 2464 <ol> 2465 <li>If an application has never called 2466 <code>android.hardware.Camera.Parameters.setPreviewFormat(int)</code>, then the 2467 device MUST use <code>android.hardware.PixelFormat.YCbCr_420_SP</code> for 2468 preview data provided to application callbacks.</li> 2469 <li>If an application registers an <code>android.hardware.Camera.PreviewCallback 2470 </code> instance and the system calls the <code>onPreviewFrame()</code> method 2471 when the preview format is YCbCr_420_SP, the data in the <code>byte[]</code> 2472 passed into <code>onPreviewFrame()</code> must further be in the NV21 encoding 2473 format. That is, NV21 MUST be the default.</li> 2474 <li>Device implementations MUST support the YV12 format (as denoted by the 2475 <code>android.graphics.ImageFormat.YV12</code> constant) for camera previews 2476 for both front- and rear-facing cameras. (The hardware video encoder and camera 2477 may use any native pixel format, but the device implementation MUST support conversion 2478 to YV12.)</li> 2479 </ol> 2480 <p>Device implementations MUST implement the full Camera API included in the 2481 Android SDK documentation [<a href="#resources51">Resources, 51</a>]), 2482 regardless of whether the device includes hardware autofocus or other 2483 capabilities. For instance, cameras that lack autofocus MUST still call any 2484 registered <code>android.hardware.Camera.AutoFocusCallback</code> instances (even though 2485 this has no relevance to a non-autofocus camera.) Note that this does apply 2486 to front-facing cameras; for instance, even though most front-facing cameras 2487 do not support autofocus, the API callbacks must still be "faked" as 2488 described.</p> 2489 <p>Device implementations MUST recognize and honor each parameter name defined 2490 as a constant on the <code>android.hardware.Camera.Parameters</code> class, if the 2491 underlying hardware supports the feature. If the device hardware does not 2492 support a feature, the API must behave as documented. Conversely, Device 2493 implementations MUST NOT honor or recognize string constants passed 2494 to the <code>android.hardware.Camera.setParameters()</code> method other than 2495 those documented as constants on the 2496 <code>android.hardware.Camera.Parameters</code>. That is, 2497 device implementations MUST support all standard Camera parameters if the 2498 hardware allows, and MUST NOT support custom Camera parameter types. 2499 For instance, device implementations that support image capture using high dynamic range (HDR) 2500 imaging techniques MUST support camera parameter <code>Camera.SCENE_MODE_HDR</code> 2501 [<a href="#resources78">Resources, 78</a>]).</p> 2502 <p>Device implementations MUST broadcast the <code>Camera.ACTION_NEW_PICTURE</code> 2503 intent whenever a new picture is taken by the camera and the entry of the picture 2504 has been added to the media store.</p> 2505 <p>Device implementations MUST broadcast the <code>Camera.ACTION_NEW_VIDEO</code> 2506 intent whenever a new video is recorded by the camera and the entry of the picture 2507 has been added to the media store.</p> 2508 <a name="section-7.5.4"></a><h4 id="section-7.5.4">7.5.4. Camera Orientation</h4> 2509 <p>Both front- and rear-facing cameras, if present, MUST be oriented so that 2510 the long dimension of the camera aligns with the screen's long dimension. That 2511 is, when the device is held in the landscape orientation, cameras MUST 2512 capture images in the landscape orientation. This applies regardless of the 2513 device's natural orientation; that is, it applies to landscape-primary devices 2514 as well as portrait-primary devices.</p> 2515 2516 <a name="section-7.6"></a><h3 id="section-7.6">7.6. Memory and Storage</h3> 2517 <a name="section-7.6.1"></a><h4 id="section-7.6.1">7.6.1. Minimum Memory and Storage</h4> 2518 <p>Device implementations MUST have at least 340MB of memory available to the 2519 kernel and userspace. The 340MB MUST be in addition to any memory dedicated to 2520 hardware components such as radio, video, and so on that is not under the 2521 kernel's control.</p> 2522 <p>Device implementations with less than 512MB of memory available to the kernel 2523 and userspace MUST return the value "true" for 2524 <code>ActivityManager.isLowRamDevice()</code>.</p> 2525 <p>Device implementations MUST have at least 1GB of non-volatile storage available 2526 for application private data. That is, the <code>/data</code> partition MUST be at 2527 least 1GB. Device implementations that run Android are <b>very strongly encouraged to 2528 have at least 2GB of non-volatile storage for application private data</b> so they will be 2529 able to upgrade to the future platform releases.</p> 2530 2531 <p>The Android APIs include a Download Manager that applications may use to 2532 download data files [<a href="#resources56">Resources, 56</a>]. The device 2533 implementation of the Download Manager MUST be capable of downloading individual 2534 files of at least 100MB in size to the default "cache" location.</p> 2535 <a name="section-7.6.2"></a><h4 id="section-7.6.2">7.6.2. Shared External Storage</h4> 2536 <p>Device implementations MUST offer shared storage for applications. The 2537 shared storage provided MUST be at least 1GB in size.</p> 2538 <p>Device implementations MUST be configured with shared storage mounted by 2539 default, "out of the box". If the shared storage is not mounted on the Linux 2540 path <code>/sdcard</code>, then the device MUST include a Linux symbolic link 2541 from <code>/sdcard</code> to the actual mount point.</p> 2542 <p>Device implementations MUST enforce as documented the 2543 <code>android.permission.WRITE_EXTERNAL_STORAGE</code> permission on this 2544 shared storage. Shared storage MUST otherwise be writable by any application 2545 that obtains that permission.</p> 2546 <p>Device implementations MAY have hardware for user-accessible removable 2547 storage, such as a Secure Digital card. Alternatively, device implementations 2548 MAY allocate internal (non-removable) storage as shared storage for apps. The 2549 upstream Android Open Source Project includes an implementation that uses 2550 internal device storage for shared external storage APIs; device implementations 2551 SHOULD use this configuration and software implementation.</p> 2552 <p>Regardless of the form of shared storage used, device implementations MUST 2553 provide some mechanism to access the contents of shared storage from a host 2554 computer, such as USB mass storage (UMS) or Media Transfer Protocol (MTP). Device 2555 implementations MAY use USB mass storage, but SHOULD use Media Transfer 2556 Protocol. If the device implementation supports Media Transfer Protocol:</p> 2557 <ul> 2558 <li>The device implementation SHOULD be compatible with the reference Android 2559 MTP host, Android File Transfer [<a href="#resources57">Resources, 57</a>].</li> 2560 <li>The device implementation SHOULD report a USB device class of <code>0x00</code>.</li> 2561 <li>The device implementation SHOULD report a USB interface name of 'MTP'.</li> 2562 </ul> 2563 <p>If the device implementation lacks USB ports, it MUST provide a host 2564 computer with access to the contents of shared storage by some other means, 2565 such as a network file system.</p> 2566 <p>It is illustrative to consider two common examples. If a device 2567 implementation includes an SD card slot to satisfy the shared storage 2568 requirement, a FAT-formatted SD card 1GB in size or larger MUST be included 2569 with the device as sold to users, and MUST be mounted by default. 2570 Alternatively, if a device implementation uses internal fixed storage to 2571 satisfy this requirement, that storage MUST be 1GB in size or larger 2572 and mounted on <code>/sdcard</code> (or <code>/sdcard</code> 2573 MUST be a symbolic link to the physical location if it is mounted elsewhere.)</p> 2574 <p>Device implementations that include multiple shared storage paths (such as 2575 both an SD card slot and shared internal storage) MUST NOT allow Android 2576 applications to write to the secondary external storage, except for their 2577 package-specific directories on the secondary external storage, but SHOULD 2578 expose content from both storage paths transparently through Android's media 2579 scanner service and android.provider.MediaStore.</p> 2580 2581 <a name="section-7.7"></a><h3 id="section-7.7">7.7. USB</h3> 2582 <p>Device implementations SHOULD include a USB client port, and SHOULD include 2583 a USB host port.</p> 2584 <p>If a device implementation includes a USB client port:</p> 2585 <ul> 2586 <li>the port MUST be connectable to a USB host with a standard USB-A port</li> 2587 <li>the port SHOULD use the micro USB form factor on the device side. Existing and 2588 new devices that run Android are <b>very strongly encouraged to meet these requirements 2589 in Android</b> so they will be able to upgrade to the future platform releases</li> 2590 <li>the port SHOULD be centered in the middle of an edge. Device implementations SHOULD either 2591 locate the port on the bottom of the device (according to natural orientation) or enable software 2592 screen rotation for all apps (including home screen), so that the display draws correctly when the device 2593 is oriented with the port at bottom. Existing and new devices that run Androidare <b>very strongly 2594 encouraged to meet these requirements in Android</b> so they will be able to upgrade to future platform releases.</li> 2595 <li>if the device has other ports (such as a non-USB charging port) it SHOULD be on the same edge as the 2596 micro-USB port</li> 2597 <li>it MUST allow a host connected to the device to access the contents of the 2598 shared storage volume using either USB mass storage or Media Transfer 2599 Protocol</li> 2600 <li>it MUST implement the Android Open Accessory API and specification as documented 2601 in the Android SDK documentation, and MUST declare support for the hardware 2602 feature <code>android.hardware.usb.accessory</code> [<a href="#resources52">Resources, 2603 52</a>]</li> 2604 <li>it MUST implement the USB audio class as documented in the Android SDK documentation [<a href="#resources66">Resources, 66</a>]</li> 2605 <li>it SHOULD implement support for USB battery charging specification [<a href="#resources64">Resources, 64</a>] 2606 Existing and new devices that run Android are <b>very strongly encouraged to 2607 meet these requirements</b> 2608 so they will be able to upgrade to the future platform releases</li> 2609 <li>The value of iSerialNumber in USB standard device descriptor MUST be equal to the value of android.os.Build.SERIAL.</li> 2610 </ul> 2611 <p>If a device implementation includes a USB host port:</p> 2612 <ul> 2613 <li>it MAY use a non-standard port form factor, but if so MUST ship with a 2614 cable or cables adapting the port to standard USB-A</li> 2615 <li>it MUST implement the Android USB host API as documented in the Android 2616 SDK, and MUST declare support for the hardware feature 2617 <code>android.hardware.usb.host</code> [<a href="#resources53">Resources, 53</a>]</li> 2618 </ul> 2619 <p>Device implementations MUST implement the Android Debug Bridge. If a device 2620 implementation omits a USB client port, it MUST implement the Android Debug 2621 Bridge via local-area network (such as Ethernet or 802.11)</p> 2622 2623 <a name="section-8"></a><h2 id="section-8">8. Performance Compatibility</h2> 2624 <p>Device implementations MUST meet the key performance metrics of an Android- 2625 compatible device defined in the table below:</p> 2626 <table><tbody><tr> 2627 <td><b>Metric</b></td> 2628 <td><b>Performance Threshold</b></td> 2629 <td><b>Comments</b></td> 2630 </tr> 2631 <tr> 2632 <td>Application Launch Time</td> 2633 <td>The following applications should launch within the specified time.<ul> 2634 <li>Browser: less than 1300ms</li> 2635 <li>Contacts: less than 700ms</li> 2636 <li>Settings: less than 700ms</li> 2637 </ul></td> 2638 <td>The launch time is measured as the total time to 2639 complete loading the default activity for the application, including the time 2640 it takes to start the Linux process, load the Android package into the Dalvik 2641 VM, and call onCreate.</td> 2642 </tr> 2643 <tr> 2644 <td>Simultaneous Applications</td> 2645 <td>When multiple applications have been launched, re-launching an 2646 already-running application after it has been launched must take less than the 2647 original launch time.</td> 2648 <td> </td> 2649 </tr> 2650 </tbody> 2651 </table> 2652 2653 <a name="section-9"></a><h2 id="section-9">9. Security Model Compatibility</h2> 2654 <p>Device implementations MUST implement a security model consistent with the 2655 Android platform security model as defined in Security and Permissions 2656 reference document in the APIs [<a href="#resources54">Resources, 54</a>] in the 2657 Android developer documentation. Device implementations MUST support 2658 installation of self-signed applications without requiring any additional 2659 permissions/certificates from any third parties/authorities. Specifically, 2660 compatible devices MUST support the security mechanisms described in the 2661 follow sub-sections.</p> 2662 <a name="section-9.1"></a><h3 id="section-9.1">9.1. Permissions</h3> 2663 <p>Device implementations MUST support the Android permissions model as 2664 defined in the Android developer documentation [<a 2665 href="#resources54">Resources, 54</a>]. Specifically, 2666 implementations MUST enforce each permission defined as described in the SDK 2667 documentation; no permissions may be omitted, altered, or ignored. 2668 Implementations MAY add additional permissions, provided the new permission ID 2669 strings are not in the android.* namespace.</p> 2670 <a name="section-9.2"></a><h3 id="section-9.2">9.2. UID and Process Isolation</h3> 2671 <p>Device implementations MUST support the Android application sandbox model, 2672 in which each application runs as a unique Unix-style UID and in a separate 2673 process. Device implementations MUST support running multiple applications as 2674 the same Linux user ID, provided that the applications are properly signed and 2675 constructed, as defined in the Security and Permissions reference [<a 2676 href="#resources54">Resources, 54</a>].</p> 2677 <a name="section-9.3"></a><h3 id="section-9.3">9.3. Filesystem Permissions</h3> 2678 <p>Device implementations MUST support the Android file access permissions 2679 model as defined in the Security and Permissions reference [<a 2680 href="#resources54">Resources, 54</a>].</p> 2681 <a name="section-9.4"></a><h3 id="section-9.4">9.4. Alternate Execution Environments</h3> 2682 <p>Device implementations MAY include runtime environments that execute 2683 applications using some other software or technology than the Dalvik virtual 2684 machine or native code. However, such alternate execution environments MUST 2685 NOT compromise the Android security model or the security of installed Android 2686 applications, as described in this section.</p> 2687 <p>Alternate runtimes MUST themselves be Android applications, and abide by 2688 the standard Android security model, as described elsewhere in Section 9.</p> 2689 <p>Alternate runtimes MUST NOT be granted access to resources protected by 2690 permissions not requested in the runtime's AndroidManifest.xml file via the 2691 <code><uses-permission></code> mechanism.</p> 2692 <p>Alternate runtimes MUST NOT permit applications to make use of features 2693 protected by Android permissions restricted to system applications.</p> 2694 <p>Alternate runtimes MUST abide by the Android sandbox model. Specifically:</p> 2695 <ul> 2696 <li>Alternate runtimes SHOULD install apps via the PackageManager into 2697 separate Android sandboxes (that is, Linux user IDs, etc.)</li> 2698 <li>Alternate runtimes MAY provide a single Android sandbox shared by all 2699 applications using the alternate runtime</li> 2700 <li>Alternate runtimes and installed applications using an alternate runtime 2701 MUST NOT reuse the sandbox of any other app installed on the device, except 2702 through the standard Android mechanisms of shared user ID and signing 2703 certificate</li> 2704 <li>Alternate runtimes MUST NOT launch with, grant, or be granted access to 2705 the sandboxes corresponding to other Android applications</li> 2706 </ul> 2707 <p>Alternate runtimes MUST NOT be launched with, be granted, or grant to other 2708 applications any privileges of the superuser (root), or of any other user ID.</p> 2709 <p>The .apk files of alternate runtimes MAY be included in the system image of 2710 a device implementation, but MUST be signed with a key distinct 2711 from the key used to sign other applications included with the device 2712 implementation.</p> 2713 <p>When installing applications, alternate runtimes MUST obtain user consent 2714 for the Android permissions used by the application. That is, if an 2715 application needs to make use of a device resource for which there is a 2716 corresponding Android permission (such as Camera, GPS, etc.), the alternate 2717 runtime MUST inform the user that the application will be able to access 2718 that resource. If the runtime environment does not record application 2719 capabilities in this manner, the runtime environment MUST list all 2720 permissions held by the runtime itself when installing any application 2721 using that runtime.</p> 2722 2723 <a name="section-9.5"></a><h3 id="section-9.5">9.5. Multi-User Support </h3> 2724 <p>Android includes support for multiple users and provides support for full user isolation 2725 [<a href="#resources70">Resources, 70</a>].</p> 2726 <p>Device implementations MUST meet these requirements related to multi-user support [<a href="#resources71">Resources, 71</a>]:</p> 2727 <ul> 2728 <li>As the behavior of the telephony APIs on devices with multiple users is currently undefined, device implementations that 2729 declare android.hardware.telephony MUST NOT enable multi-user support. </li> 2730 <li>Device implementations MUST, for each user, implement a security model consistent with the Android platform security model 2731 as defined in Security and Permissions reference document in the APIs [Resources, 54]</li> 2732 <li>Android includes support for restricted profiles, a feature that allows device owners to manage additional users and their capabilities 2733 on the device. With restricted profiles, device owners can quickly set up separate environments for additional users to work in, with the ability to 2734 manage finer-grained restrictions in the apps that are available in those environments. Device implementations that include support for multiple users 2735 MUST include support for restricted profiles. The upstream Android Open Source Project includes an implementation that satisfies this requirement.</li> 2736 </ul> 2737 2738 <p>Each user instance on an Android device MUST have separate and isolated external storage directories. Device implementations MAY store multiple users' data on the same volume or filesystem. 2739 However, the device implementation MUST ensure that applications owned by and running on behalf a given user cannot list, read, or write to data owned by any other user. 2740 Note that removable media, such as SD card slots, can allow one user to access another's data by means of a host PC. For this reason, device implementations that use removable media for the 2741 external storage APIs MUST encrypt the contents of the SD card if multi-user is enabled using a key stored only on non-removable media accessible only to the system. As this will make the 2742 media unreadable by a host PC, device implementations will be required to switch to MTP or a similar system to provide host PCs with access to the current user's data. Accordingly, device 2743 implementations MAY but SHOULD NOT enable multi-user if they use removable media [<a href="#resources72">Resources, 72</a>] for primary external storage.</p> 2744 2745 <a name="section-9.6"></a><h3 id="section-9.6">9.6. Premium SMS Warning</h3> 2746 <p>Android includes support for warning users for any outgoing premium SMS message [<a href="#resources73">Resources, 73</a>] . Premium SMS messages are text messages sent to a service registered with a carrier that may incur a charge to the user. 2747 Device implementations that declare support for <code>android.hardware.telephony</code> MUST warn users before sending a SMS message to numbers identified by regular expressions defined in <code>/data/misc/sms/codes.xml</code> file in the device. 2748 The upstream Android Open Source Project provides an implementation that satisfies this requirement. 2749 </p> 2750 2751 <a name="section-9.7"></a><h3 id="section-9.7">9.7. Kernel Security Features</h3> 2752 <p>The Android Sandbox includes features that can use the Security-Enhanced 2753 Linux (SELinux) mandatory access control (MAC) system and other security 2754 features in the Linux kernel. SELinux or any other security features, if 2755 implemented below the Android framework:</p> 2756 <ul> 2757 <li>MUST maintain compatibility with existing applications</li> 2758 <li>MUST not have a visible user interface, even when violations are detected 2759 </li> 2760 <li>SHOULD NOT be user or developer configurable</li> 2761 </ul> 2762 <p>If any API for configuration of policy is exposed to an application that can 2763 affect another application (such as a Device Administration API), the API MUST 2764 NOT allow configurations that break compatibility.</p> 2765 <p>Devices MUST implement SELinux and meet the following requirements, which 2766 are satisfied by the reference implementation in the upstream Android Open 2767 Source Project.</p> 2768 <ul> 2769 <li>it MUST support a SELinux policy that allows the SELinux mode to be set on 2770 a per-domain basis with:</li> 2771 <ul> 2772 <li>domains that are in enforcing mode in the upstream Android Open Source 2773 implementation (such as installd, netd, and vold) MUST be in enforcing mode 2774 </li> 2775 <li>domain(s) for third-party applications SHOULD remain in permissive mode to 2776 ensure continued compatibility</li> 2777 </ul> 2778 <li>it SHOULD load policy from <code>/sepolicy</code> file on the device</li> 2779 <li>it MUST support dynamic updates of the SELinux policy file without requiring 2780 a system image update</li> 2781 <li>it MUST log any policy violations without breaking applications or affecting 2782 system behavior</li> 2783 </ul> 2784 2785 <p>Device implementations SHOULD retain the default SELinux policy provided in 2786 the upstream Android Open Source Project, until they have first audited their 2787 additions to the SELinux policy. Device implementations MUST be compatible with 2788 the upstream Android Open Source Project.</p> 2789 2790 <a name="section-9.8"></a><h3 id="section-9.8">9.8. Privacy</h3> 2791 <p>If the device implements functionality in the system that captures the 2792 contents displayed on the screen and/or records the audio stream played on the 2793 device, it MUST continuously notify the user whenever this functionality is 2794 enabled and actively capturing/recording.</p> 2795 2796 <a name="section-9.9"></a><h3 id="section-9.9">9.9. Full-Disk Encryption</h3> 2797 <p>IF the device has lockscreen, the device MUST support full-disk 2798 encryption.</p> 2799 2800 <a name="section-10"></a><h2 id="section-10">10. Software Compatibility Testing</h2> 2801 <p>Device implementations MUST pass all tests described in this section.</p> 2802 <p>However, note that no software test package is fully comprehensive. For 2803 this reason, device implementers are very strongly encouraged to make the 2804 minimum number of changes as possible to the reference and preferred 2805 implementation of Android available from the Android Open Source Project. 2806 This will minimize the risk of introducing bugs that create incompatibilities 2807 requiring rework and potential device updates.</p> 2808 <a name="section-10.1"></a><h3 id="section-10.1">10.1. Compatibility Test Suite</h3> 2809 <p>Device implementations MUST pass the Android Compatibility Test Suite (CTS) 2810 [<a href="#resources02">Resources, 2</a>] available from the Android Open Source 2811 Project, using the final shipping software on the device. Additionally, device 2812 implementers SHOULD use the reference implementation in the Android Open 2813 Source tree as much as possible, and MUST ensure compatibility in cases of 2814 ambiguity in CTS and for any reimplementations of parts of the reference 2815 source code.</p> 2816 <p>The CTS is designed to be run on an actual device. Like any software, the 2817 CTS may itself contain bugs. The CTS will be versioned independently of this 2818 Compatibility Definition, and multiple revisions of the CTS may be released 2819 for Android 4.4. Device implementations MUST pass the latest CTS version 2820 available at the time the device software is completed.</p> 2821 <a name="section-10.2"></a><h3 id="section-10.2">10.2. CTS Verifier</h3> 2822 <p>Device implementations MUST correctly execute all applicable cases in the 2823 CTS Verifier. The CTS Verifier is included with the Compatibility Test Suite, 2824 and is intended to be run by a human operator to test functionality that 2825 cannot be tested by an automated system, such as correct functioning of a 2826 camera and sensors.</p> 2827 <p>The CTS Verifier has tests for many kinds of hardware, including some 2828 hardware that is optional. Device implementations MUST pass all tests for 2829 hardware which they possess; for instance, if a device possesses an 2830 accelerometer, it MUST correctly execute the Accelerometer test case in the 2831 CTS Verifier. Test cases for features noted as optional by this Compatibility 2832 Definition Document MAY be skipped or omitted.</p> 2833 <p>Every device and every build MUST correctly run the CTS Verifier, as noted 2834 above. However, since many builds are very similar, device implementers are 2835 not expected to explicitly run the CTS Verifier on builds that differ only in 2836 trivial ways. Specifically, device implementations that differ from an 2837 implementation that has passed the CTS Verifier only by the set of included 2838 locales, branding, etc. MAY omit the CTS Verifier test.</p> 2839 <a name="section-10.3"></a><h3 id="section-10.3">10.3. Reference Applications</h3> 2840 <p>Device implementers MUST test implementation compatibility using the 2841 following open source applications:</p> 2842 <ul> 2843 <li>The "Apps for Android" applications [<a href="#resources55">Resources, 55</a>]</li> 2844 <li>Replica Island (available in Google Play Store)</li> 2845 </ul> 2846 <p>Each app above MUST launch and behave correctly on the implementation, for 2847 the implementation to be considered compatible.</p> 2848 2849 2850 <a name="section-11"></a><h2 id="section-11">11. Updatable Software</h2> 2851 <p>Device implementations MUST include a mechanism to replace the entirety of 2852 the system software. The mechanism need not perform "live" upgrades - that 2853 is, a device restart MAY be required.</p> 2854 <p>Any method can be used, provided that it can replace the entirety of the 2855 software preinstalled on the device. For instance, any of the following 2856 approaches will satisfy this requirement:</p> 2857 <ul> 2858 <li>Over-the-air (OTA) downloads with offline update via reboot</li> 2859 <li>"Tethered" updates over USB from a host PC</li> 2860 <li>"Offline" updates via a reboot and update from a file on removable 2861 storage</li> 2862 </ul> 2863 <p>The update mechanism used MUST support updates without wiping user data. 2864 That is, the update mechanism MUST preserve application private data 2865 and application shared data. Note that the upstream Android software includes 2866 an update mechanism that satisfies this requirement.</p> 2867 <p>If an error is found in a device implementation after it has been released 2868 but within its reasonable product lifetime that is determined in consultation 2869 with the Android Compatibility Team to affect the compatibility of third-party 2870 applications, the device implementer MUST correct the error via a software 2871 update available that can be applied per the mechanism just described.</p> 2872 2873 <a name="section-12"></a><h2 id="section-12">12. Document Changelog</h2> 2874 <p>The following table contains a summary of the changes to the Compatibility Definition in this release.</p> 2875 <table width="100%" border="1"> 2876 <tr> 2877 <th width="25%" scope="col">Section(s)</th> 2878 <th width="75%" scope="col">Summary of change</th> 2879 </tr> 2880 <tr> 2881 <td>3.2.2. Build Parameters</td> 2882 <td>Revised descriptions of BRAND, DEVICE, and PRODUCT. SERIAL is now 2883 required.</td> 2884 </tr> 2885 <tr> 2886 <td>3.2.3.5. Default App Settings</td> 2887 <td>New section that adds requirement to comply with new default 2888 application settings</td> 2889 </tr> 2890 <tr> 2891 <td>3.3.1 Application Binary Interfaces</td> 2892 <td>Clarified allowed values for the <code>android.os.Build.CPU_ABI</code> 2893 and <code>android.os.Build.CPU_ABI2</code> parameters.</td> 2894 </tr> 2895 <tr> 2896 <td>3.4.1. WebView Compatibility</td> 2897 <td>Added Chromium as required WebView implementation.</td> 2898 </tr> 2899 <tr> 2900 <td>3.7. Virtual Machine Compatibility</td> 2901 <td>Added requirement for xxhdpi and 400dpi screen densities.</td> 2902 </tr> 2903 <tr> 2904 <td>3.8.6. Themes</td> 2905 <td>Updated to reflect use of translucent system bars.</td> 2906 </tr> 2907 <tr> 2908 <td>3.8.12. Location</td> 2909 <td>New section that adds requirement location settings be centralized.</td> 2910 </tr> 2911 <tr> 2912 <td>3.8.13. Unicode</td> 2913 <td>New section that adds requirement for emoji support.</td> 2914 </tr> 2915 <tr> 2916 <td>3.9. Device Administration</td> 2917 <td>Noted preinstalled administrative applications cannot be the default 2918 Device Owner application.</td> 2919 </tr> 2920 <tr> 2921 <td>5.1. Media Codecs</td> 2922 <td>Added VP9 decoder requirement. Added recommended specification for 2923 hardware VP8 codecs.</td> 2924 </tr> 2925 <tr> 2926 <td>5.3. Video Decoding</td> 2927 <td>Added VP9. Added recommendation for dynamic resolution switching.</td> 2928 </tr> 2929 <tr> 2930 <td>5.4. Audio Recording</td> 2931 <td>Added <code>REMOTE_SUBMIX</code> as new required audio source. Made use 2932 of <code>android.media.audiofx.NoiseSuppressor</code> API a requirement.</td> 2933 </tr> 2934 <tr> 2935 <td>6.2.1 Experimental</td> 2936 <td>New section that introduces the ART runtime and requires Dalvik as the 2937 default runtime.</td> 2938 </tr> 2939 <tr> 2940 <td>7.1.1. Screen Configuration</td> 2941 <td>Replaced 1.85 aspect ratio with 1.86. Added 400dpi screen density.</td> 2942 </tr> 2943 <tr> 2944 <td>7.1.6. Screen Types</td> 2945 <td>Added 640 dpi (4K) resolution configuration.</td> 2946 </tr> 2947 <tr> 2948 <td>7.2.3. Navigation keys</td> 2949 <td>Added Recents function as essential; demoted Menu function in priority.</td> 2950 </tr> 2951 <tr> 2952 <td>7.3.6. Thermometer</td> 2953 <td>Added SENSOR_TYPE_AMBIENT_TEMPERATURE as recommended thermometer.</td> 2954 </tr> 2955 <tr> 2956 <td>7.4.2.2. Wi-Fi Tunneled Direct Link Setup</td> 2957 <td>New section that adds support for Wi-Fi Tunneled Direct Link Setup 2958 (TDLS).</td> 2959 </tr> 2960 <tr> 2961 <td>7.4.4. Near-Field Communications</td> 2962 <td>Added Host Card Emulation (HCE) as a requirement. Replaced SNEP GET with 2963 Logical Link Control Protocol (LLCP) and added the Bluetooth Object Push 2964 Profile as a requirement.</td> 2965 </tr> 2966 <tr> 2967 <td>7.4.6. Sync Settings</td> 2968 <td>New section that adds requirement auto-sync data be enabled by default.</td> 2969 </tr> 2970 <tr> 2971 <td>7.6.1. Minimum Memory and Storage</td> 2972 <td>Added <code>ActivityManager.isLowRamDevice()</code> setting requirement 2973 for devices with less than 512MB of memory. Increased storage requirements 2974 from 512MB and 1GB to 1GB and 2GB, respectively.</td> 2975 </tr> 2976 <tr> 2977 <td>7.6.2. Shared "External" Storage</td> 2978 <td>Editorial fixes such as change of section name, and moved text that fits 2979 in this section from section 9.5. Noted applications may write to their 2980 package-specific directories on secondary external storage.</td> 2981 </tr> 2982 <tr> 2983 <td>7.7. USB</td> 2984 <td>Added requirement all devices report a USB serial number.</td> 2985 </tr> 2986 <tr> 2987 <td>9.5. Multi-User Support</td> 2988 <td>Moved non multi-user specific text to section 7.6.2.</td> 2989 </tr> 2990 <tr> 2991 <td>9.7. Kernel Security Features</td> 2992 <td>Rewritten to note switch of SELinux to enforcing mode and requirement 2993 SELinux output not be rendered in the user interface.</td> 2994 </tr> 2995 <tr> 2996 <td>9.8. Privacy</td> 2997 <td>New section that adds requirement audio and video recording must trigger 2998 continuous notifications to the user.</td> 2999 </tr> 3000 <tr> 3001 <td>9.9. Full-Disk Encryption</td> 3002 <td>New section that adds requirement devices with lockscreen support full-disk encryption.</td> 3003 </tr> 3004 <tr> 3005 <td>12. Document Changelog</td> 3006 <td>New section that summarizes changes in the CDD by section.</td> 3007 </tr> 3008 </table> 3009 <p> </p> 3010 3011 <a name="section-13"></a><h2 id="section-13">13. Contact Us</h2> 3012 <p>You can contact the document authors at <a 3013 href="mailto:compatibility (a] android.com">compatibility (a] android.com</a> for 3014 clarifications and to bring up any issues that you think the document does not 3015 cover.</p> 3016 3017 <div style="page-break-before: always;"></div> 3018 3019 <div id="footerContent" xmlns:pdf="http://whatever"> 3020 <pdf:pagenumber/> 3021 </div> 3022 </body> 3023 </html> 3024
