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 4.3 Compatibility Definition</title> 6 <link rel="stylesheet" type="text/css" href="cdd.css"/> 7 </head> 8 <body> 9 <h1>Android 4.3 Compatibility Definition</h1> 10 <!-- 11 <span style="color: red; font-weight: bold;"><h2>Revision 1</h2></span><br/> 12 <span style="color: red;">Last updated: July 23, 2013</span> 13 --> 14 <p><b><font color="red">Revision 1</font></b><br/> 15 Last updated: July 23, 2013 16 </p> 17 <p>Copyright © 2013, Google Inc. All rights reserved.<br/> 18 <a href="mailto:compatibility (a] android.com">compatibility (a] android.com</a> 19 </p> 20 21 <h2> Table of Contents</h2> 22 <div style="margin-left: 2em;"> 23 <a href="#section-1">1. Introduction</a><br/> 24 <a href="#section-2">2. Resources</a><br/> 25 <a href="#section-3">3. Software</a><br/> 26 <div style="margin-left: 2em;"> 27 <a href="#section-3.1">3.1. Managed API Compatibility</a><br/> 28 <a href="#section-3.2">3.2. Soft API Compatibility</a><br/> 29 <div style="margin-left: 2em;"> 30 <a href="#section-3.2.1">3.2.1. Permissions</a><br/> 31 <a href="#section-3.2.2">3.2.2. Build Parameters</a><br/> 32 <a href="#section-3.2.3">3.2.3. Intent Compatibility</a><br/> 33 <div style="margin-left: 2em;"> 34 <a href="#section-3.2.3.1">3.2.3.1. Core Application Intents</a><br/> 35 <a href="#section-3.2.3.2">3.2.3.2. Intent Overrides</a><br/> 36 <a href="#section-3.2.3.3">3.2.3.3. Intent Namespaces</a><br/> 37 <a href="#section-3.2.3.4">3.2.3.4. Broadcast Intents</a><br/> 38 </div> 39 </div> 40 <a href="#section-3.3">3.3. Native API Compatibility</a><br/> 41 <div style="margin-left: 2em;"> 42 <a href="#section-3.3.1">3.3.1 Application Binary Interfaces</a><br/> 43 </div> 44 <a href="#section-3.4">3.4. Web Compatibility</a><br/> 45 <div style="margin-left: 2em;"> 46 <a href="#section-3.4.1">3.4.1. WebView Compatibility</a><br/> 47 <a href="#section-3.4.2">3.4.2. Browser Compatibility</a><br/> 48 </div> 49 <a href="#section-3.5">3.5. API Behavioral Compatibility</a><br/> 50 <a href="#section-3.6">3.6. API Namespaces</a><br/> 51 <a href="#section-3.7">3.7. Virtual Machine Compatibility</a><br/> 52 <a href="#section-3.8">3.8. User Interface Compatibility</a><br/> 53 <div style="margin-left: 2em;"> 54 <a href="#section-3.8.1">3.8.1. Launcher (Home Screen)</a><br/> 55 <a href="#section-3.8.2">3.8.2. Widgets</a><br/> 56 <a href="#section-3.8.3">3.8.3. Notifications</a><br/> 57 <a href="#section-3.8.4">3.8.4. Search</a><br/> 58 <a href="#section-3.8.5">3.8.5. Toasts</a><br/> 59 <a href="#section-3.8.6">3.8.6. Themes</a><br/> 60 <a href="#section-3.8.7">3.8.7. Live Wallpapers</a><br/> 61 <a href="#section-3.8.8">3.8.8. Recent Application Display</a><br/> 62 <a href="#section-3.8.9">3.8.9. Input Management</a><br/> 63 <a href="#section-3.8.10">3.8.10. Lock Screen Media Remote Control</a><br/> 64 <a href="#section-3.8.11">3.8.11. Dreams</a><br/> 65 </div> 66 <a href="#section-3.9">3.9 Device Administration</a><br/> 67 <a href="#section-3.10">3.10 Accessibility</a><br/> 68 <a href="#section-3.11">3.11 Text-to-Speech</a><br/> 69 </div> 70 <a href="#section-4">4. Application Packaging Compatibility</a><br/> 71 <a href="#section-5">5. Multimedia Compatibility</a><br/> 72 <div style="margin-left: 2em;"> 73 <a href="#section-5.1">5.1. Media Codecs</a><br/> 74 <a href="#section-5.2">5.2. Video Encoding</a><br/> 75 <a href="#section-5.3">5.3. Video Decoding</a><br/> 76 <a href="#section-5.4">5.4. Audio Recording</a><br/> 77 <a href="#section-5.5">5.5. Audio Latency</a><br/> 78 <a href="#section-5.6">5.6. Network Protocols</a><br/> 79 </div> 80 <a href="#section-6">6. Developer Tools and Options Compatibility</a><br/> 81 <div style="margin-left: 2em;"> 82 <a href="#section-6.1">6.1. Developer Tools</a><br/> 83 <a href="#section-6.2">6.2. Developer Options</a><br/> 84 </div> 85 <a href="#section-7">7. Hardware Compatibility</a><br/> 86 <div style="margin-left: 2em;"> 87 <a href="#section-7.1">7.1. Display and Graphics</a><br/> 88 <div style="margin-left: 2em;"> 89 <a href="#section-7.1.1">7.1.1. Screen Configuration</a><br/> 90 <a href="#section-7.1.2">7.1.2. Display Metrics</a><br/> 91 <a href="#section-7.1.3">7.1.3. Screen Orientation</a><br/> 92 <a href="#section-7.1.4">7.1.4. 2D and 3D Graphics Acceleration</a><br/> 93 <a href="#section-7.1.5">7.1.5. Legacy Application Compatibility Mode</a><br/> 94 <a href="#section-7.1.6">7.1.6. Screen Types</a><br/> 95 <a href="#section-7.1.7">7.1.7. Screen Technology</a><br/> 96 <a href="#section-7.1.8">7.1.8. External Displays</a><br/> 97 </div> 98 <a href="#section-7.2">7.2. Input Devices</a><br/> 99 <div style="margin-left: 2em;"> 100 <a href="#section-7.2.1">7.2.1. Keyboard</a><br/> 101 <a href="#section-7.2.2">7.2.2. Non-touch Navigation</a><br/> 102 <a href="#section-7.2.3">7.2.3. Navigation keys</a><br/> 103 <a href="#section-7.2.4">7.2.4. Touchscreen input</a><br/> 104 <a href="#section-7.2.5">7.2.5. Fake touch input</a><br/> 105 <a href="#section-7.2.6">7.2.6. Microphone</a><br/> 106 </div> 107 <a href="#section-7.3">7.3. Sensors</a><br/> 108 <div style="margin-left: 2em;"> 109 <a href="#section-7.3.1">7.3.1. Accelerometer</a><br/> 110 <a href="#section-7.3.2">7.3.2. Magnetometer</a><br/> 111 <a href="#section-7.3.3">7.3.3. GPS</a><br/> 112 <a href="#section-7.3.4">7.3.4. Gyroscope</a><br/> 113 <a href="#section-7.3.5">7.3.5. Barometer</a><br/> 114 <a href="#section-7.3.6">7.3.6. Thermometer</a><br/> 115 <a href="#section-7.3.7">7.3.7. Photometer</a><br/> 116 <a href="#section-7.3.8">7.3.8. Proximity Sensor</a><br/> 117 </div> 118 <a href="#section-7.4">7.4. Data Connectivity</a><br/> 119 <div style="margin-left: 2em;"> 120 <a href="#section-7.4.1">7.4.1. Telephony</a><br/> 121 <a href="#section-7.4.2">7.4.2. IEEE 802.11 (WiFi)</a><br/> 122 <div style="margin-left: 2em;"> 123 <a href="#section-7.4.2.1">7.4.2.1. WiFi Direct</a><br/> 124 </div> 125 <a href="#section-7.4.3">7.4.3. Bluetooth</a><br/> 126 <a href="#section-7.4.4">7.4.4. Near-Field Communications</a><br/> 127 <a href="#section-7.4.5">7.4.5. Minimum Network Capability</a><br/> 128 </div> 129 <a href="#section-7.5">7.5. Cameras</a><br/> 130 <div style="margin-left: 2em;"> 131 <a href="#section-7.5.1">7.5.1. Rear-Facing Camera</a><br/> 132 <a href="#section-7.5.2">7.5.2. Front-Facing Camera</a><br/> 133 <a href="#section-7.5.3">7.5.3. Camera API Behavior</a><br/> 134 <a href="#section-7.5.4">7.5.4. Camera Orientation</a><br/> 135 </div> 136 <a href="#section-7.6">7.6. Memory and Storage</a><br/> 137 <div style="margin-left: 2em;"> 138 <a href="#section-7.6.1">7.6.1. Minimum Memory and Storage</a><br/> 139 <a href="#section-7.6.2">7.6.2. Application Shared Storage</a><br/> 140 </div> 141 <a href="#section-7.7">7.7. USB</a><br/> 142 </div> 143 <a href="#section-8">8. Performance Compatibility</a><br/> 144 <a href="#section-9">9. Security Model Compatibility</a><br/> 145 <div style="margin-left: 2em;"> 146 <a href="#section-9.1">9.1. Permissions</a><br/> 147 <a href="#section-9.2">9.2. UID and Process Isolation</a><br/> 148 <a href="#section-9.3">9.3. Filesystem Permissions</a><br/> 149 <a href="#section-9.4">9.4. Alternate Execution Environments</a><br/> 150 <a href="#section-9.5">9.5. Multi-User Support</a><br/> 151 <a href="#section-9.6">9.6. Premium SMS Warning</a><br/> 152 <a href="section-9.7">9.7. Kernel Security Features</a><br/> 153 </div> 154 <a href="#section-10">10. Software Compatibility Testing</a><br/> 155 <div style="margin-left: 2em;"> 156 <a href="#section-10.1">10.1. Compatibility Test Suite</a><br/> 157 <a href="#section-10.2">10.2. CTS Verifier</a><br/> 158 <a href="#section-10.3">10.3. Reference Applications</a><br/> 159 </div> 160 <a href="#section-11">11. Updatable Software</a><br/> 161 <a href="#section-12">12. Contact Us</a><br/> 162 </div> 163 164 <div style="page-break-before: always;"></div> 165 166 <a name="section-1"></a><h2>1. Introduction</h2> 167 <p>This document enumerates the requirements that must be met in order for 168 devices to be compatible with Android 4.3.</p> 169 <p>The use of "must", "must not", "required", "shall", "shall not", "should", 170 "should not", "recommended", "may" and "optional" is per the IETF standard 171 defined in RFC2119 [<a href="#resources01">Resources, 1</a>].</p> 172 <p>As used in this document, a "device implementer" or "implementer" is a 173 person or organization developing a hardware/software solution running Android 174 4.3. A "device implementation" or "implementation" is the hardware/software 175 solution so developed.</p> 176 <p>To be considered compatible with Android 4.3, device implementations 177 MUST meet the requirements presented in this Compatibility Definition, 178 including any documents incorporated via reference.</p> 179 <p>Where this definition or the software tests described in <a 180 href="#section-10">Section 10</a> is silent, ambiguous, or incomplete, it is 181 the responsibility of the device implementer to ensure compatibility with 182 existing implementations.</p> 183 <p>For this reason, the Android Open Source Project [<a 184 href="#resources03">Resources, 3</a>] is both the reference and preferred 185 implementation of Android. Device implementers are strongly encouraged to base 186 their implementations to the greatest extent possible on the "upstream" source 187 code available from the Android Open Source Project. While some components can 188 hypothetically be replaced with alternate implementations this practice is 189 strongly discouraged, as passing the software tests will become substantially 190 more difficult. It is the implementer's responsibility to ensure full 191 behavioral compatibility with the standard Android implementation, including 192 and beyond the Compatibility Test Suite. Finally, note that certain component 193 substitutions and modifications are explicitly forbidden by this document.</p> 194 <a name="section-2"></a><h2>2. Resources</h2> 195 <ol> 196 <a name="resources01"></a><li>IETF RFC2119 Requirement Levels: <a href="http://www.ietf.org/rfc/rfc2119.txt">http://www.ietf.org/rfc/rfc2119.txt</a></li> 197 <a name="resources02"></a><li>Android Compatibility Program Overview: <a href="http://source.android.com/compatibility/index.html">http://source.android.com/compatibility/index.html</a></li> 198 <a name="resources03"></a><li>Android Open Source Project: <a href="http://source.android.com/">http://source.android.com/</a></li> 199 <a name="resources04"></a><li>API definitions and documentation: <a href="http://developer.android.com/reference/packages.html">http://developer.android.com/reference/packages.html</a></li> 200 <a name="resources05"></a><li>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> 201 <a name="resources06"></a><li>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> 202 <a name="resources07"></a><li>Android 4.3 allowed version strings: <a href="http://source.android.com/compatibility/4.3/versions.html">http://source.android.com/compatibility/4.3/versions.html</a></li> 203 <a name="resources08"></a><li>Renderscript: <a href="http://developer.android.com/guide/topics/graphics/renderscript.html">http://developer.android.com/guide/topics/graphics/renderscript.html</a></li> 204 <a name="resources09"></a><li>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> 205 <a name="resources10"></a><li>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> 206 <a name="resources11"></a><li>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> 207 <a name="resources12"></a><li>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> 208 <a name="resources13"></a><li>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> 209 <a name="resources14"></a><li>HTML5/W3C geolocation API: <a href="http://www.w3.org/TR/geolocation-API/">http://www.w3.org/TR/geolocation-API/</a></li> 210 <a name="resources15"></a><li>HTML5/W3C webdatabase API: <a href="http://www.w3.org/TR/webdatabase/">http://www.w3.org/TR/webdatabase/</a></li> 211 <a name="resources16"></a><li>HTML5/W3C IndexedDB API: <a href="http://www.w3.org/TR/IndexedDB/">http://www.w3.org/TR/IndexedDB/</a></li> 212 <a name="resources17"></a><li>Dalvik Virtual Machine specification: available in the Android source code, at dalvik/docs</li> 213 <a name="resources18"></a><li>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> 214 <a name="resources19"></a><li>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> 215 <a name="resources20"></a><li>Application Resources: <a href="http://code.google.com/android/reference/available-resources.html">http://code.google.com/android/reference/available-resources.html</a></li> 216 <a name="resources21"></a><li>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> 217 <a name="resources22"></a><li>Search Manager: <a href="http://developer.android.com/reference/android/app/SearchManager.html">http://developer.android.com/reference/android/app/SearchManager.html</a></li> 218 <a name="resources23"></a><li>Toasts: <a href="http://developer.android.com/reference/android/widget/Toast.html">http://developer.android.com/reference/android/widget/Toast.html</a></li> 219 <a name="resources24"></a><li>Themes: <a href="http://developer.android.com/guide/topics/ui/themes.html">http://developer.android.com/guide/topics/ui/themes.html</a></li> 220 <a name="resources25"></a><li>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> 221 <a name="resources26"></a><li>Live Wallpapers: <a href="http://developer.android.com/resources/articles/live-wallpapers.html">http://developer.android.com/resources/articles/live-wallpapers.html</a></li> 222 <a name="resources27"></a><li>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> 223 <a name="resources28"></a><li>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> 224 <a name="resources29"></a><li>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> 225 <a name="resources30"></a><li>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> 226 <a name="resources31"></a><li>Eyes Free project: <a href="http://http://code.google.com/p/eyes-free">http://code.google.com/p/eyes-free</a></li> 227 <a name="resources32"></a><li>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> 228 <a name="resources33"></a><li>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> 229 <a name="resources34"></a><li>Android apk file description: <a href="http://developer.android.com/guide/topics/fundamentals.html">http://developer.android.com/guide/topics/fundamentals.html</a></li> 230 <a name="resources35"></a><li>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> 231 <a name="resources36"></a><li>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> 232 <a name="resources37"></a><li>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> 233 <a name="resources38"></a><li>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> 234 <a name="resources39"></a><li>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> 235 <a name="resources40"></a><li>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> 236 <a name="resources41"></a><li>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> 237 <a name="resources42"></a><li>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> 238 <a name="resources43"></a><li>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> 239 <a name="resources44"></a><li>MIFARE MF1S503X: <a href="http://www.nxp.com/documents/data_sheet/MF1S503x.pdf">http://www.nxp.com/documents/data_sheet/MF1S503x.pdf</a></li> 240 <a name="resources45"></a><li>MIFARE MF1S703X: <a href="http://www.nxp.com/documents/data_sheet/MF1S703x.pdf">http://www.nxp.com/documents/data_sheet/MF1S703x.pdf</a></li> 241 <a name="resources46"></a><li>MIFARE MF0ICU1: <a href="http://www.nxp.com/documents/data_sheet/MF0ICU1.pdf">http://www.nxp.com/documents/data_sheet/MF0ICU1.pdf</a></li> 242 <a name="resources47"></a><li>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> 243 <a name="resources48"></a><li>MIFARE AN130511: <a href="http://www.nxp.com/documents/application_note/AN130511.pdf">http://www.nxp.com/documents/application_note/AN130511.pdf</a></li> 244 <a name="resources49"></a><li>MIFARE AN130411: <a href="http://www.nxp.com/documents/application_note/AN130411.pdf">http://www.nxp.com/documents/application_note/AN130411.pdf</a></li> 245 <a name="resources50"></a><li>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> 246 <a name="resources51"></a><li>Camera: <a href="http://developer.android.com/reference/android/hardware/Camera.html">http://developer.android.com/reference/android/hardware/Camera.html</a></li> 247 <a name="resources52"></a><li>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> 248 <a name="resources53"></a><li>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> 249 <a name="resources54"></a><li>Android Security and Permissions reference: <a href="http://developer.android.com/guide/topics/security/security.html">http://developer.android.com/guide/topics/security/security.html</a></li> 250 <a name="resources55"></a><li>Apps for Android: <a href="http://code.google.com/p/apps-for-android">http://code.google.com/p/apps-for-android</a></li> 251 <a name="resources56"></a><li>Android DownloadManager: <a href="http://developer.android.com/reference/android/app/DownloadManager.html">http://developer.android.com/reference/android/app/DownloadManager.html</a></li> 252 <a name="resources57"></a><li>Android File Transfer: <a href="http://www.android.com/filetransfer">http://www.android.com/filetransfer</a></li> 253 <a name="resources58"></a><li>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> 254 <a name="resources59"></a><li>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> 255 <a name="resources60"></a><li>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> 256 <a name="resources61"></a><li>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> 257 <a name="resources62"></a><li>Wifi 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> 258 <a name="resources63"></a><li>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> 259 <a name="resources64"></a><li>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> 260 <a name="resources65"></a><li>Android Beam: <a href="http://developer.android.com/guide/topics/nfc/nfc.html">http://developer.android.com/guide/topics/nfc/nfc.html</a></li> 261 <a name="resources66"></a><li>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> 262 <a name="resources67"></a><li>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> 263 <a name="resources68"></a><li>Wifi Direct (Wifi 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> 264 <a name="resources69"></a><li>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> 265 <a name="resources70"></a><li>UserManager reference: <a href="http://developer.android.com/reference/android/os/UserManager.html">http://developer.android.com/reference/android/os/UserManager.html</a></li> 266 <a name="resources71"></a><li>External Storage reference: <a href="http://source.android.com/tech/storage">http://source.android.com/tech/storage</a></li> 267 <a name="resources72"></a><li>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> 268 <a name="resources73"></a><li>SMS Short Code: <a href="http://en.wikipedia.org/wiki/Short_code">http://en.wikipedia.org/wiki/Short_code</a></li> 269 <a name="resources74"></a><li>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> 270 <a name="resources75"></a><li>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> 271 <a name="resources76"></a><li>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> 272 <a name="resources77"></a><li>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> 273 <a name="resources78"></a><li>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> 274 <a name="resources79"></a><li>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> 275 <a name="resources80"></a><li>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> 276 <a name="resources81"></a><li>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> 277 </ol> 278 <p>Many of these resources are derived directly or indirectly from the Android 279 4.3 SDK, and will be functionally identical to the information in that SDK's 280 documentation. In any cases where this Compatibility Definition or the 281 Compatibility Test Suite disagrees with the SDK documentation, the SDK 282 documentation is considered authoritative. Any technical details provided in 283 the references included above are considered by inclusion to be part of this 284 Compatibility Definition.</p> 285 286 <a name="section-3"></a><h2>3. Software</h2> 287 <a name="section-3.1"></a><h3>3.1. Managed API Compatibility</h3> 288 <p>The managed (Dalvik-based) execution environment is the primary vehicle for 289 Android applications. The Android application programming interface (API) is 290 the set of Android platform interfaces exposed to applications running in the 291 managed VM environment. Device implementations MUST provide complete 292 implementations, including all documented behaviors, of any documented API 293 exposed by the Android 4.3 SDK [<a href="#resources04">Resources, 4</a>].</p> 294 <p>Device implementations MUST NOT omit any managed APIs, alter API interfaces 295 or signatures, deviate from the documented behavior, or include no-ops, except 296 where specifically allowed by this Compatibility Definition.</p> 297 <p>This Compatibility Definition permits some types of hardware for which 298 Android includes APIs to be omitted by device implementations. In such cases, 299 the APIs MUST still be present and behave in a reasonable way. See 300 <a href="#section-7">Section 7</a> for specific requirements for this scenario. 301 </p> 302 303 <a name="section-3.2"></a><h3>3.2. Soft API Compatibility</h3> 304 <p>In addition to the managed APIs from Section 3.1, Android also includes a 305 significant runtime-only "soft" API, in the form of such things such as 306 Intents, permissions, and similar aspects of Android applications that cannot 307 be enforced at application compile time.</p> 308 <a name="section-3.2.1"></a><h4>3.2.1. Permissions</h4> 309 <p>Device implementers MUST support and enforce all permission constants as 310 documented by the Permission reference page [<a 311 href="#resources05">Resources, 5</a>]. Note that Section 9 lists additional 312 requirements related to the Android security model.</p> 313 <a name="section-3.2.2"></a><h4>3.2.2. Build Parameters</h4> 314 <p>The Android APIs include a number of constants on the <code>android.os.Build</code> 315 class [<a href="#resources06">Resources, 6</a>] that are intended to describe 316 the current device. To provide consistent, meaningful values across device 317 implementations, the table below includes additional restrictions on the 318 formats of these values to which device implementations MUST conform.</p> 319 <table> 320 <tbody> 321 <tr> 322 <td><b>Parameter</b></td> 323 <td><b>Comments</b></td> 324 </tr> 325 <tr> 326 <td>android.os.Build.VERSION.RELEASE</td> 327 <td>The version of the currently-executing Android system, in human-readable 328 format. This field MUST have one of the string values defined in [<a 329 href="#resources07">Resources, 7</a>].</td> 330 </tr> 331 <tr> 332 <td>android.os.Build.VERSION.SDK</td> 333 <td>The version of the currently-executing Android system, in a format 334 accessible to third-party application code. For Android 4.3, this 335 field MUST have the integer value 18.</td> 336 </tr> 337 <tr> 338 <td>android.os.Build.VERSION.SDK_INT</td> 339 <td>The version of the currently-executing Android system, in a format 340 accessible to third-party application code. For Android 4.3, this 341 field MUST have the integer value 18.</td> 342 </tr> 343 <tr> 344 <td>android.os.Build.VERSION.INCREMENTAL</td> 345 <td>A value chosen by the device implementer designating the specific build of 346 the currently-executing Android system, in human-readable format. This value 347 MUST NOT be re-used for different builds made available to end users. A typical use 348 of this field is to indicate which build number or source-control change 349 identifier was used to generate the build. There are no requirements on the 350 specific format of this field, except that it MUST NOT be null or the empty 351 string ("").</td> 352 </tr> 353 <tr> 354 <td>android.os.Build.BOARD</td> 355 <td>A value chosen by the device implementer identifying the specific internal 356 hardware used by the device, in human-readable format. A possible use of this 357 field is to indicate the specific revision of the board powering the device. 358 The value of this field MUST be encodable as 7-bit ASCII and match the regular expression 359 <code>"^[a-zA-Z0-9.,_-]+$"</code>.</td> 360 </tr> 361 <tr> 362 <td>android.os.Build.BRAND</td> 363 <td>A value chosen by the device implementer identifying the name of the 364 company, organization, individual, etc. who produced the device, in 365 human-readable format. A possible use of this field is to indicate the OEM 366 and/or carrier who sold the device. The value of this field MUST be 367 encodable as 7-bit ASCII and match the regular expression 368 <code>"^[a-zA-Z0-9.,_-]+$"</code>. 369 </td> 370 </tr> 371 <tr> 372 <td>android.os.Build.CPU_ABI</td> 373 <td>The name of the instruction set (CPU type + ABI convention) of native code. 374 See <a href="#section-3.3">Section 3.3: Native API Compatibility</a>. 375 </td> 376 </tr> 377 <tr> 378 <td>android.os.Build.CPU_ABI2</td> 379 <td>The name of the second instruction set (CPU type + ABI convention) of native code. 380 See <a href="#section-3.3">Section 3.3: Native API Compatibility</a>. 381 </td> 382 </tr> 383 <tr> 384 <td>android.os.Build.DEVICE</td> 385 <td>A value chosen by the device implementer identifying the specific 386 configuration or revision of the body (sometimes called "industrial design") 387 of the device. The value of this field MUST be encodable as 7-bit ASCII and 388 match the regular expression <code>"^[a-zA-Z0-9.,_-]+$"</code>.</td> 389 </tr> 390 <tr> 391 <td>android.os.Build.FINGERPRINT</td> 392 <td>A string that uniquely identifies this build. It SHOULD be reasonably 393 human-readable. It MUST follow this template: 394 <br/><code>$(BRAND)/$(PRODUCT)/$(DEVICE):$(VERSION.RELEASE)/$(ID)/$(VERSION.INCREMENTAL):$(TYPE)/$(TAGS)</code><br/> 395 For example: 396 <br/><code>acme/mydevice/generic:4.3/JRN53/3359:userdebug/test-keys</code><br/> 397 The fingerprint MUST NOT include whitespace characters. If other fields included in the 398 template above have whitespace characters, they MUST be replaced in the build 399 fingerprint with another character, such as the underscore ("_") character. 400 The value of this field MUST be encodable as 7-bit ASCII.</td> 401 </tr> 402 <tr> 403 <td>android.os.Build.HARDWARE</td> 404 <td>The name of the hardware (from the kernel command line or /proc). It SHOULD be 405 reasonably human-readable. The value of this field MUST be encodable as 7-bit ASCII and 406 match the regular expression <code>"^[a-zA-Z0-9.,_-]+$"</code>.</td> 407 </tr> 408 <tr> 409 <td>android.os.Build.HOST</td> 410 <td>A string that uniquely identifies the host the build was built on, in 411 human readable format. There are no requirements on the specific format of 412 this field, except that it MUST NOT be null or the empty string ("").</td> 413 </tr> 414 <tr> 415 <td>android.os.Build.ID</td> 416 <td>An identifier chosen by the device implementer to refer to a specific 417 release, in human readable format. This field can be the same as 418 android.os.Build.VERSION.INCREMENTAL, but SHOULD be a value sufficiently 419 meaningful for end users to distinguish between software builds. The value of 420 this field MUST be encodable as 7-bit ASCII and match the regular expression 421 <code>"^[a-zA-Z0-9.,_-]+$"</code>. 422 </td> 423 </tr> 424 <tr> 425 <td>android.os.Build.MANUFACTURER</td> 426 <td>The trade name of the Original Equipment Manufacturer (OEM) of the product. 427 There are no requirements on the specific format of this field, except that it 428 MUST NOT be null or the empty string ("").</td> 429 </tr> 430 <tr> 431 <td>android.os.Build.MODEL</td> 432 <td>A value chosen by the device implementer containing the name of the device 433 as known to the end user. This SHOULD be the same name under which the device 434 is marketed and sold to end users. There are no requirements on the specific 435 format of this field, except that it MUST NOT be null or the empty string 436 ("").</td> 437 </tr> 438 <tr> 439 <td>android.os.Build.PRODUCT</td> 440 <td>A value chosen by the device implementer containing the development name 441 or code name of the product (SKU). MUST be human-readable, but is not necessarily 442 intended for view by end users. The value of this field MUST be encodable as 7-bit 443 ASCII and match the regular expression 444 <code>"^[a-zA-Z0-9.,_-]+$"</code>.</td> 445 </tr> 446 <tr> 447 <td>android.os.Build.SERIAL</td> 448 <td>A hardware serial number, if available. The value of this field MUST be encodable 449 as 7-bit ASCII and match the regular expression 450 <code>"^([a-zA-Z0-9]{0,20})$"</code>.</td> 451 </tr> 452 <tr> 453 <td>android.os.Build.TAGS</td> 454 <td>A comma-separated list of tags chosen by the device implementer that 455 further distinguishes the build. For example, "unsigned,debug". The value of 456 this field MUST be encodable as 7-bit ASCII and match the regular expression 457 <code>"^[a-zA-Z0-9.,_-]+$"</code>.</td> 458 </tr> 459 <tr> 460 <td>android.os.Build.TIME</td> 461 <td>A value representing the timestamp of when the build occurred.</td> 462 </tr> 463 <tr> 464 <td>android.os.Build.TYPE</td> 465 <td>A value chosen by the device implementer specifying the runtime 466 configuration of the build. This field SHOULD have one of the values 467 corresponding to the three typical Android runtime configurations: "user", 468 "userdebug", or "eng". The value of this field MUST be 469 encodable as 7-bit ASCII and match the regular expression 470 <code>"^[a-zA-Z0-9.,_-]+$"</code>.</td> 471 </tr> 472 <tr> 473 <td>android.os.Build.USER</td> 474 <td>A name or user ID of the user (or automated user) that generated the 475 build. There are no requirements on the specific format of this field, except 476 that it MUST NOT be null or the empty string ("").</td> 477 </tr> 478 </tbody> 479 </table> 480 <a name="section-3.2.3"></a><h4>3.2.3. Intent Compatibility</h4> 481 <p> 482 Device implementations MUST honor Android's loose-coupling Intent system, as 483 described in the sections below. By "honored", it is meant that the device 484 implementer MUST provide an Android Activity or Service that specifies a 485 matching Intent filter and binds to and implements correct behavior for each 486 specified Intent pattern.</p> 487 <a name="section-3.2.3.1"></a><h4>3.2.3.1. Core Application Intents</h4> 488 <p>The Android upstream project defines a number of core applications, such as 489 contacts, calendar, photo gallery, music player, and so on. Device implementers 490 MAY replace these applications with alternative versions.</p> 491 <p>However, any such alternative versions MUST honor the same Intent patterns 492 provided by the upstream project. For example, if a device contains an 493 alternative music player, it must still honor the Intent pattern issued by 494 third-party applications to pick a song.</p> 495 <p>The following applications are considered core Android system 496 applications:</p> 497 <ul> 498 <li>Desk Clock</li> 499 <li>Browser</li> 500 <li>Calendar</li> 501 <li>Contacts</li> 502 <!--<li>Email</li>--> 503 <li>Gallery</li> 504 <li>GlobalSearch</li> 505 <li>Launcher</li> 506 <!-- <li>LivePicker (that is, the Live Wallpaper picker application; MAY be omitted 507 if the device does not support Live Wallpapers, per Section 3.8.5.)</li> --> 508 <!-- <li>Messaging (AKA "Mms")</li> --> 509 <li>Music</li> 510 <!-- <li>Phone</li> --> 511 <li>Settings</li> 512 <!-- <li>SoundRecorder</li> --> 513 </ul> 514 <p>The core Android system applications include various Activity, or Service 515 components that are considered "public". That is, the attribute 516 "android:exported" may be absent, or may have the value "true".</p> 517 <p>For every Activity or Service defined 518 in one of the core Android system apps that is not marked as non-public via an 519 android:exported attribute with the value "false", device implementations MUST 520 include a component of the same type implementing the same Intent filter 521 patterns as the core Android system app.</p> 522 <p>In other words, a device implementation MAY replace core Android system 523 apps; however, if it does, the device implementation MUST support all Intent 524 patterns defined by each core Android system app being replaced.</p> 525 <a name="section-3.2.3.2"></a><h4>3.2.3.2. Intent Overrides</h4> 526 <p>As Android is an extensible platform, device implementations MUST allow each 527 Intent pattern referenced in Section 3.2.3.2 to be overridden by third-party 528 applications. The upstream Android open source implementation allows this by 529 default; device implementers MUST NOT attach special privileges to system 530 applications' use of these Intent patterns, or prevent third-party 531 applications from binding to and assuming control of these patterns. This 532 prohibition specifically includes but is not limited to disabling the 533 "Chooser" user interface that allows the user to select between multiple 534 applications which all handle the same Intent pattern.</p> 535 <p>However, device implementations MAY provide default activities for specific 536 URI patterns (eg. http://play.google.com) if the default activity provides a 537 more specific filter for the data URI. For example, an intent filter specifying 538 the data URI "http://www.android.com" is more specific than the browser filter 539 for "http://". Device implementations MUST provide a user interface for users 540 to modify the default activity for intents.</p> 541 542 <a name="section-3.2.3.3"></a><h4>3.2.3.3. Intent Namespaces</h4> 543 <p>Device implementations MUST NOT include any Android component that honors any 544 new Intent or Broadcast Intent patterns using an ACTION, CATEGORY, or other 545 key string in the android.* or com.android.* namespace. Device implementers 546 MUST NOT include any Android components that honor any new Intent or Broadcast 547 Intent patterns using an ACTION, CATEGORY, or other key string in a package 548 space belonging to another organization. Device implementers MUST NOT alter or 549 extend any of the Intent patterns used by the core apps listed in Section 550 3.2.3.1. Device implementations MAY include Intent patterns using 551 namespaces clearly and obviously associated with their own organization.</p> 552 <p>This prohibition is analogous to that specified for Java language classes 553 in Section 3.6.</p> 554 <a name="section-3.2.3.4"></a><h4>3.2.3.4. Broadcast Intents</h4> 555 <p>Third-party applications rely on the platform to broadcast certain Intents 556 to notify them of changes in the hardware or software environment. 557 Android-compatible devices MUST broadcast the public broadcast Intents in 558 response to appropriate system events. Broadcast Intents are described in the 559 SDK documentation.</p> 560 561 <a name="section-3.3"></a><h3>3.3. Native API Compatibility</h3> 562 <a name="section-3.3.1"></a><h4>3.3.1 Application Binary Interfaces</h4> 563 <p>Managed code running in Dalvik can call into native code provided in the 564 application .apk file as an ELF .so file compiled for the appropriate device 565 hardware architecture. As native code is highly dependent on the underlying 566 processor technology, Android defines a number of Application Binary 567 Interfaces (ABIs) in the Android NDK, in the file 568 <code>docs/CPU-ARCH-ABIS.html</code>. If a device implementation is compatible 569 with one or more defined ABIs, it SHOULD implement compatibility with the 570 Android NDK, as below.</p> 571 <p>If a device implementation includes support for an Android ABI, it:</p> 572 <ul> 573 <li>MUST include support for code running in the managed environment to call 574 into native code, using the standard Java Native Interface (JNI) 575 semantics</li> 576 <li>MUST be source-compatible (i.e. header compatible) and binary-compatible 577 (for the ABI) with each required library in the list below</li> 578 <li>MUST accurately report the native Application Binary Interface (ABI) 579 supported by the device, via the <code>android.os.Build.CPU_ABI</code> 580 API</li> 581 <li>MUST report only those ABIs documented in the latest version of the 582 Android NDK, in the file <code>docs/CPU-ARCH-ABIS.txt</code></li> 583 <li>SHOULD be built using the source code and header files available in the 584 upstream Android Open Source Project</li> 585 </ul> 586 <p>The following native code APIs MUST be available to apps that include 587 native code:</p> 588 <ul> 589 <li>libc (C library)</li> 590 <li>libm (math library)</li> 591 <li>Minimal support for C++</li> 592 <li>JNI interface</li> 593 <li>liblog (Android logging)</li> 594 <li>libz (Zlib compression)</li> 595 <li>libdl (dynamic linker)</li> 596 <li>libGLESv1_CM.so (OpenGL ES 1.0)</li> 597 <li>libGLESv2.so (OpenGL ES 2.0)</li> 598 <li>libGLESv3.so (OpenGL ES 3.0)</li> 599 <li>libEGL.so (native OpenGL surface management)</li> 600 <li>libjnigraphics.so</li> 601 <li>libOpenSLES.so (OpenSL ES 1.0.1 audio support)</li> 602 <li>libOpenMAXAL.so (OpenMAX AL 1.0.1 support)</li> 603 <li>libandroid.so (native Android activity support)</li> 604 <li>Support for OpenGL, as described below</li> 605 </ul> 606 <p>Note that future releases of the Android NDK may introduce support for 607 additional ABIs. If a device implementation is not compatible with an existing 608 predefined ABI, it MUST NOT report support for any ABI at all.</p> 609 <p>Note that device implementations MUST include libGLESv3.so and it MUST symlink (symbolic) 610 link to libGLESv2.so. On device implementations that declare support for OpenGL ES 3.0, libGLESv2.so 611 MUST export the OpenGL ES 3.0 function symbols in addition to the OpenGL ES 2.0 function symbols.</p> 612 <p>Native code compatibility is challenging. For this reason, it should be 613 repeated that device implementers are VERY strongly encouraged to use the 614 upstream implementations of the libraries listed above to help ensure 615 compatibility.</p> 616 617 <a name="section-3.4"></a><h3>3.4. Web Compatibility</h3> 618 <a name="section-3.4.1"></a><h4>3.4.1. WebView Compatibility</h4> 619 <p>The Android Open Source implementation uses the WebKit rendering engine to 620 implement the <code>android.webkit.WebView</code> [<a href="#resources10">Resources, 10</a>] . Because it is not feasible 621 to develop a comprehensive test suite for a web rendering system, device 622 implementers MUST use the specific upstream build of WebKit in the WebView 623 implementation. Specifically:</p> 624 <ul> 625 <li>Device implementations' <code>android.webkit.WebView</code> 626 implementations MUST be based on the 534.30 WebKit build from the upstream 627 Android Open Source tree for Android 4.3. This build includes a specific set 628 of functionality and security fixes for the WebView. Device implementers MAY 629 include customizations to the WebKit implementation; however, any such 630 customizations MUST NOT alter the behavior of the WebView, including rendering 631 behavior.</li> 632 <li>The user agent string reported by the WebView MUST be in this format:<br/> 633 <code>Mozilla/5.0 (Linux; U; Android $(VERSION); $(LOCALE); $(MODEL) Build/$(BUILD)) AppleWebKit/534.30 (KHTML, like Gecko) Version/4.0 Mobile Safari/534.30</code> 634 <ul> 635 <li>The value of the $(VERSION) string MUST be the same as the value for <code>android.os.Build.VERSION.RELEASE</code></li> 636 <li>The value of the $(LOCALE) string SHOULD follow the ISO conventions for country code and language, and SHOULD refer to the current configured locale of the device</li> 637 <li>The value of the $(MODEL) string MUST be the same as the value for <code>android.os.Build.MODEL</code></li> 638 <li>The value of the $(BUILD) string MUST be the same as the value for <code>android.os.Build.ID</code></li> 639 <li>Device implementations MAY omit <code>Mobile</code> in the user agent string</li> 640 </ul> 641 </li> 642 </ul> 643 <p>The WebView component SHOULD include support for as much of HTML5 [<a 644 href="#resources11">Resources, 11</a>] as possible. 645 Minimally, device implementations MUST support each of these APIs associated 646 with HTML5 in the WebView:</p> 647 <ul> 648 <li>application cache/offline operation [<a href="#resources12">Resources, 12</a>]</li> 649 <li>the <video> tag [<a href="#resources13">Resources, 13</a>]</li> 650 <li>geolocation [<a href="#resources14">Resources, 14</a>]</li> 651 </ul> 652 <p>Additionally, device implementations MUST support the HTML5/W3C webstorage 653 API [<a href="#resources15">Resources, 15</a>], and SHOULD support the 654 HTML5/W3C IndexedDB API [<a href="#resources16">Resources, 16</a>]. <i>Note 655 that as the web development standards bodies are transitioning to favor 656 IndexedDB over webstorage, IndexedDB is expected to become a required 657 component in a future version of Android.</i></p> 658 <p>HTML5 APIs, like all JavaScript APIs, MUST be disabled by default in a 659 WebView, unless the developer explicitly enables them via the usual Android 660 APIs.</p> 661 662 <a name="section-3.4.2"></a><h4>3.4.2. Browser Compatibility</h4> 663 <p>Device implementations MUST include a standalone Browser application for 664 general user web browsing. The standalone Browser MAY be based on a 665 browser technology other than WebKit. However, even if an alternate Browser 666 application is used, the <code>android.webkit.WebView</code> component 667 provided to third-party applications MUST be based on WebKit, as described in 668 Section 3.4.1.</p> 669 <p>Implementations MAY ship a custom user agent string in the standalone 670 Browser application.</p> 671 <p>The standalone Browser application (whether based on the upstream 672 WebKit Browser application or a third-party replacement) SHOULD include support 673 for as much of HTML5 [<a href="#resources11">Resources, 11</a>] as possible. 674 Minimally, device implementations MUST support each of these APIs associated 675 with HTML5:</p> 676 <ul> 677 <li>application cache/offline operation [<a href="#resources12">Resources, 12</a>]</li> 678 <li>the <video> tag [<a href="#resources13">Resources, 13</a>]</li> 679 <li>geolocation [<a href="#resources14">Resources, 14</a>]</li> 680 </ul> 681 <p>Additionally, device implementations MUST support the HTML5/W3C webstorage 682 API [<a href="#resources15">Resources, 15</a>], and SHOULD support the 683 HTML5/W3C IndexedDB API [<a href="#resources16">Resources, 16</a>]. <i>Note 684 that as the web development standards bodies are transitioning to favor 685 IndexedDB over webstorage, IndexedDB is expected to become a required 686 component in a future version of Android.</i></p> 687 688 <a name="section-3.5"></a><h3>3.5. API Behavioral Compatibility</h3> 689 <p>The behaviors of each of the API types (managed, soft, native, and web) 690 must be consistent with the preferred implementation of the upstream Android 691 Open Source Project [<a href="#resources03">Resources, 3</a>]. Some specific areas 692 of compatibility are:</p> 693 <ul> 694 <li>Devices MUST NOT change the behavior or semantics of a standard Intent</li> 695 <li>Devices MUST NOT alter the lifecycle or lifecycle semantics of a 696 particular type of system component (such as Service, Activity, 697 ContentProvider, etc.)</li> 698 <li>Devices MUST NOT change the semantics of a standard permission</li> 699 </ul> 700 <p>The above list is not comprehensive. The Compatibility Test Suite (CTS) 701 tests significant portions of the platform for behavioral compatibility, but 702 not all. It is the responsibility of the implementer to ensure behavioral 703 compatibility with the Android Open Source Project. For this reason, device 704 implementers SHOULD use the source code available via the Android Open Source 705 Project where possible, rather than re-implement significant parts of the 706 system.</p> 707 708 709 <a name="section-3.6"></a><h3>3.6. API Namespaces</h3> 710 <p>Android follows the package and class namespace conventions defined by the 711 Java programming language. To ensure compatibility with third-party 712 applications, device implementers MUST NOT make any prohibited modifications 713 (see below) to these package namespaces:</p> 714 <ul> 715 <li>java.*</li> 716 <li>javax.*</li> 717 <li>sun.*</li> 718 <li>android.*</li> 719 <li>com.android.*</li> 720 </ul> 721 <p>Prohibited modifications include:</p> 722 <ul> 723 <li>Device implementations MUST NOT modify the publicly exposed APIs on the 724 Android platform by changing any method or class signatures, or by removing 725 classes or class fields.</li> 726 <li>Device implementers MAY modify the underlying implementation of the APIs, 727 but such modifications MUST NOT impact the stated behavior and Java-language 728 signature of any publicly exposed APIs.</li> 729 <li>Device implementers MUST NOT add any publicly exposed elements (such as 730 classes or interfaces, or fields or methods to existing classes or interfaces) 731 to the APIs above.</li> 732 </ul> 733 <p>A "publicly exposed element" is any construct which is not decorated with 734 the "@hide" marker as used in the upstream Android source code. In other 735 words, device implementers MUST NOT expose new APIs or alter existing APIs in 736 the namespaces noted above. Device implementers MAY make internal-only 737 modifications, but those modifications MUST NOT be advertised or otherwise 738 exposed to developers.</p> 739 <p>Device implementers MAY add custom APIs, but any such APIs MUST NOT be in a 740 namespace owned by or referring to another organization. For instance, device 741 implementers MUST NOT add APIs to the com.google.* or similar namespace; only 742 Google may do so. Similarly, Google MUST NOT add APIs to other companies' 743 namespaces. Additionally, if a device implementation includes custom APIs 744 outside the standard Android namespace, those APIs MUST be packaged in an 745 Android shared library so that only apps that explicitly use them (via the 746 <code><uses-library></code> mechanism) are affected by the increased 747 memory usage of such APIs.</p> 748 <p>If a device implementer proposes to improve one of the package namespaces 749 above (such as by adding useful new functionality to an existing API, or 750 adding a new API), the implementer SHOULD visit source.android.com and begin 751 the process for contributing changes and code, according to the information on 752 that site.</p> 753 <p>Note that the restrictions above correspond to standard conventions for 754 naming APIs in the Java programming language; this section simply aims to 755 reinforce those conventions and make them binding through inclusion in this 756 compatibility definition.</p> 757 758 <a name="section-3.7"></a><h3>3.7. Virtual Machine Compatibility</h3> 759 <p>Device implementations MUST support the full Dalvik Executable (DEX) 760 bytecode specification and Dalvik Virtual Machine semantics [<a 761 href="#resources17">Resources, 17</a>].</p> 762 <p>Device implementations MUST configure Dalvik to allocate memory in 763 accordance with the upstream Android platform, and as specified by the following 764 table. (See <a href="#section-7.1.1">Section 7.1.1</a> for screen size and screen 765 density definitions.)</p> 766 767 <p>Note that memory values specified below are considered minimum values, 768 and device implementations MAY allocate more memory per application.</p> 769 <table> 770 <tbody> 771 <tr> 772 <td><b>Screen Size</b></td> 773 <td><b>Screen Density</b></td> 774 <td><b>Application Memory</b></td> 775 </tr> 776 <tr> 777 <td>small / normal / large</td> 778 <td>ldpi / mdpi</td> 779 <td>16MB</td> 780 </tr> 781 <tr> 782 <td>small / normal / large</td> 783 <td>tvdpi / hdpi</td> 784 <td>32MB</td> 785 </tr> 786 <tr> 787 <td>small / normal / large</td> 788 <td>xhdpi</td> 789 <td>64MB</td> 790 </tr> 791 <tr> 792 <td>xlarge</td> 793 <td>mdpi</td> 794 <td>32MB</td> 795 </tr> 796 <tr> 797 <td>xlarge</td> 798 <td>tvdpi / hdpi</td> 799 <td>64MB</td> 800 </tr> 801 <tr> 802 <td>xlarge</td> 803 <td>xhdpi</td> 804 <td>128MB</td> 805 </tr> 806 </tbody> 807 </table> 808 809 <a name="section-3.8"></a><h3>3.8. User Interface Compatibility</h3> 810 811 <a name="section-3.8.1"></a><h4>3.8.1. Launcher (Home Screen)</h4> 812 <p>Android 4.3 includes a launcher application (home screen) and support for third party applications to replace the device 813 launcher (home screen). Device implementations that allow third party applications to replace the device home screen 814 MUST declare the platform feature <code>android.software.home_screen</code>.</p> 815 816 <a name="section-3.8.2"></a><h4>3.8.2. Widgets</h4> 817 <p>Android defines a component type and corresponding API and lifecycle that allows applications to expose an "AppWidget" 818 to the end user [<a href="#resources18">Resources, 18</a>]. Device implementations that support embedding widgets on the 819 home screen MUST meet the following requirements and declare support for platform feature <code>android.software.app_widgets</code>.</p> 820 <ul> 821 <li>Device launchers MUST include built-in support for AppWidgets, and expose user 822 interface affordances to add, configure, view, and remove AppWidgets directly within the Launcher.</li> 823 <li>Device implementations MUST be capable of rendering widgets that are 4 x 4 in the standard grid size. 824 (See the App Widget Design Guidelines in the Android SDK documentation [<a href="#resources18">Resources, 18</a>] for details.</li> 825 <li>Device implementations that include support for lock screen MUST support application widgets on the lock screen.</li> 826 </ul> 827 828 <a name="section-3.8.3"></a><h4>3.8.3. Notifications</h4> 829 <p>Android includes APIs that allow developers to notify users of notable 830 events [<a href="#resources19">Resources, 19</a>], using hardware and software 831 features of the device.</p> 832 <p>Some APIs allow applications to perform notifications or attract attention 833 using hardware, specifically sound, vibration, and light. Device implementations 834 MUST support notifications that use hardware features, as described in the SDK 835 documentation, and to the extent possible with the device implementation 836 hardware. For instance, if a device implementation includes a vibrator, it 837 MUST correctly implement the vibration APIs. If a device implementation lacks 838 hardware, the corresponding APIs MUST be implemented as no-ops. Note that this 839 behavior is further detailed in <a href="#section-7">Section 7.</a></p> 840 <p>Additionally, the implementation MUST correctly render all resources 841 (icons, sound files, etc.) provided for in the APIs [<a 842 href="#resources20">Resources, 20</a>], or in the 843 Status/System Bar icon style guide [<a href="#resources21">Resources, 21</a>]. 844 Device implementers MAY provide an alternative user experience for 845 notifications than that provided by the reference Android Open Source 846 implementation; however, such alternative notification systems MUST support 847 existing notification resources, as above.</p> 848 <p>Android 4.3 includes support for rich notifications, such as interactive 849 Views for ongoing notifications. Device implementations MUST properly display 850 and execute rich notifications, as documented in the Android APIs.</p> 851 <a name="section-3.8.4"></a><h4>3.8.4. Search</h4> 852 <p>Android includes APIs [<a href="#resources22">Resources, 22</a>] that allow 853 developers to incorporate search into their applications, and expose their 854 application's data into the global system search. Generally speaking, this 855 functionality consists of a single, system-wide user interface that allows users 856 to enter queries, displays suggestions as users type, and displays results. The 857 Android APIs allow developers to reuse this interface to provide search within 858 their own apps, and allow developers to supply results to the common global 859 search user interface.</p> 860 <p>Device implementations MUST include a single, shared, system-wide search 861 user interface capable of real-time suggestions in response to user input. 862 Device implementations MUST implement the APIs that allow developers to reuse 863 this user interface to provide search within their own applications. Device 864 implementations MUST implement the APIs that allow third-party applications to 865 add suggestions to the search box when it is run in global search mode. If no 866 third-party applications are installed that make use of this functionality, 867 the default behavior SHOULD be to display web search engine results and 868 suggestions.</p> 869 <a name="section-3.8.5"></a><h4>3.8.5. Toasts</h4> 870 <p>Applications can use the "Toast" API (defined in [<a 871 href="#resources23">Resources, 23</a>]) to 872 display short non-modal strings to the end user, that disappear after a brief 873 period of time. Device implementations MUST display Toasts from applications 874 to end users in some high-visibility manner.</p> 875 876 <a name="section-3.8.6"></a><h4>3.8.6. Themes</h4> 877 <p>Android provides "themes" as a mechanism for applications to apply styles 878 across an entire Activity or application. Android 4.3 includes a "Holo" 879 or "holographic" theme as a set of defined styles for application developers to 880 use if they want to match the Holo theme look and feel as defined by the Android 881 SDK [<a href="#resources24">Resources, 24</a>]. Device implementations MUST NOT 882 alter any of the Holo theme attributes exposed to applications 883 [<a href="#resources25">Resources, 25</a>].</p> 884 <p>Android 4.3 includes a new "Device Default" theme as a set of defined 885 styles for application developers to use if they want to match the look and feel 886 of the device theme as defined by the device implementer. Device implementations 887 MAY modify the DeviceDefault theme attributes exposed to applications 888 [<a href="#resources25">Resources, 25</a>].</p> 889 890 <a name="section-3.8.7"></a><h4>3.8.7. Live Wallpapers</h4> 891 <p>Android defines a component type and corresponding API and lifecycle that 892 allows applications to expose one or more "Live Wallpapers" to the end user 893 [<a href="#resources26">Resources, 26</a>]. Live Wallpapers are animations, 894 patterns, or similar images with limited input capabilities that display as a 895 wallpaper, behind other applications.</p> 896 <p>Hardware is considered capable of reliably running live wallpapers if it 897 can run all live wallpapers, with no limitations on functionality, at a 898 reasonable framerate with no adverse affects on other applications. If 899 limitations in the hardware cause wallpapers and/or applications to crash, 900 malfunction, consume excessive CPU or battery power, or run at unacceptably 901 low frame rates, the hardware is considered incapable of running live 902 wallpaper. As an example, some live wallpapers may use an Open GL 1.0 or 2.0 903 context to render their content. Live wallpaper will not run reliably on 904 hardware that does not support multiple OpenGL contexts because the live 905 wallpaper use of an OpenGL context may conflict with other applications that 906 also use an OpenGL context.</p> 907 <p>Device implementations capable of running live wallpapers reliably as 908 described above SHOULD implement live wallpapers. Device implementations 909 determined to not run live wallpapers reliably as described above MUST NOT 910 implement live wallpapers.</p> 911 <a name="section-3.8.8"></a><h4>3.8.8. Recent Application Display</h4> 912 <p>The upstream Android 4.3 source code includes a user interface for 913 displaying recent applications using a thumbnail image of the application's 914 graphical state at the moment the user last left the application. Device 915 implementations MAY alter or eliminate this user interface; however, a future 916 version of Android is planned to make more extensive use of this 917 functionality. Device implementations are strongly encouraged to use the 918 upstream Android 4.3 user interface (or a similar thumbnail-based interface) 919 for recent applications, or else they may not be compatible with a future 920 version of Android.</p> 921 <a name="section-3.8.9"></a><h4>3.8.9. Input Management </h4> 922 <p>Android 4.3 includes support for Input Management and support for third party input method editors. 923 Device implementations that allow users to use third party input methods on the device MUST declare the platform feature 924 <code>android.software.input_methods</code> and support IME APIs as defined in the Android SDK documentation.</p> 925 <p>Device implementations that declare the <code>android.software.input_methods</code> feature MUST provide a user-accessible mechanism 926 to add and configure third party input methods. Device implementations MUST display the settings interface in response to the 927 <code>android.settings.INPUT_METHOD_SETTINGS</code> intent.</p> 928 929 <a name="section-3.8.10"></a><h4>3.8.10. Lock Screen Media Remote Control</h4> 930 <p>Android 4.3 includes support for Remote Control API that lets media applications integrate with playback controls 931 that are displayed in a remote view like the device lock screen [<a href="#resources74">Resources, 74</a>]. Device implementations 932 that support lock screen in the device and allow users to add widgets on the home screen MUST 933 include support for embedding remote controls in the device lock screen [<a href="#resources69">Resources, 69</a>].</p> 934 935 <a name="section-3.8.11"></a><h4>3.8.11. Dreams</h4> 936 <p>Android 4.3 includes support for interactive screensavers called Dreams [<a href="#resources76">Resources, 76</a>]. 937 Dreams allows users to interact with applications when a charging device is idle, or docked in a desk dock. Device implementations 938 MUST include support for Dreams and provide a settings option for users to configure Dreams.</p> 939 940 <a name="section-3.9"></a><h3>3.9 Device Administration</h3> 941 <p>Android 4.3 includes features that allow security-aware applications 942 to perform device administration functions at the system level, such as enforcing 943 password policies or performing remote wipe, through the Android Device 944 Administration API [<a href="#resources27">Resources, 27</a>]. Device 945 implementations MUST provide an implementation of the <code>DevicePolicyManager</code> 946 class [<a href="#resources28">Resources, 28</a>]. Device implementations that include support for lock screen 947 MUST support the full range of device administration policies defined in the Android SDK 948 documentation [<a href="#resources27">Resources, 27</a>].</p> 949 950 <a name="section-3.10"></a><h3>3.10 Accessibility</h3> 951 <p>Android 4.3 provides an accessibility layer that helps users with disabilities 952 to navigate their devices more easily. In addition, Android 4.3 provides 953 platform APIs that enable accessibility service implementations to receive 954 callbacks for user and system events and generate alternate feedback mechanisms, 955 such as text-to-speech, haptic feedback, and trackball/d-pad navigation 956 [<a href="#resources29">Resources, 29</a>]. Device implementations MUST provide an 957 implementation of the Android accessibility framework consistent with the 958 default Android implementation. Specifically, device implementations MUST meet 959 the following requirements.</p> 960 <ul> 961 <li>Device implementations MUST support third party accessibility service 962 implementations through the <code>android.accessibilityservice</code> 963 APIs [<a href="#resources30">Resources, 30</a>].</li> 964 <li>Device implementations MUST generate <code>AccessibilityEvents</code> 965 and deliver these events to all registered <code>AccessibilityService 966 </code> implementations in a manner consistent with the default Android 967 implementation.</li> 968 <li>Device implementations MUST provide a user-accessible mechanism to enable 969 and disable accessibility services, and MUST display this interface in 970 response to the 971 <code>android.provider.Settings.ACTION_ACCESSIBILITY_SETTINGS</code> 972 intent.</li> 973 </ul> 974 <p>Additionally, device implementations SHOULD provide an implementation 975 of an accessibility service on the device, and SHOULD provide a mechanism 976 for users to enable the accessibility service during device setup. An open 977 source implementation of an accessibility service is available from the Eyes 978 Free project [<a href="#resources31">Resources, 31</a>].</p> 979 980 <a name="section-3.11"></a><h3>3.11 Text-to-Speech</h3> 981 <p>Android 4.3 includes APIs that allow applications to make use of 982 text-to-speech (TTS) services, and allows service providers to provide 983 implementations of TTS services [<a href="#resources32">Resources, 32</a>]. 984 Device implementations MUST meet these requirements related to the Android TTS 985 framework:</p> 986 <ul> 987 <li>Device implementations MUST support the Android TTS framework APIs and 988 SHOULD include a TTS engine supporting the languages available on the 989 device. Note that the upstream Android open source software includes a 990 full-featured TTS engine implementation.</li> 991 <li>Device implementations MUST support installation of third-party TTS 992 engines.</li> 993 <li>Device implementations MUST provide a user-accessible interface that allows 994 users to select a TTS engine for use at the system level.</li> 995 </ul> 996 997 <a name="section-4"></a><h2>4. Application Packaging Compatibility</h2> 998 <p>Device implementations MUST install and run Android ".apk" files as 999 generated by the "aapt" tool included in the official Android SDK [<a 1000 href="#resources33">Resources, 33</a>].</p> 1001 <p>Devices implementations MUST NOT extend either the .apk [<a 1002 href="#resources34">Resources, 34</a>], Android Manifest [<a 1003 href="#resources35">Resources, 35</a>], 1004 Dalvik bytecode [<a href="#resources17">Resources, 17</a>], or renderscript 1005 bytecode formats in such a way that would prevent those files from installing 1006 and running correctly on other compatible devices. Device implementers SHOULD 1007 use the reference upstream implementation of Dalvik, and the reference 1008 implementation's package management system.</p> 1009 1010 <a name="section-5"></a><h2>5. Multimedia Compatibility</h2> 1011 <p>Device implementations MUST include at least one form of audio output, such as 1012 speakers, headphone jack, external speaker connection, etc.</p> 1013 <a name="section-5.1"></a><h3>5.1. Media Codecs</h3> 1014 <p>Device implementations MUST support the core media formats specified 1015 in the Android SDK documentation [<a href="#resources58">Resources, 58</a>] except 1016 where explicitly permitted in this document. Specifically, device implementations 1017 MUST support the media formats, encoders, decoders, file types and container 1018 formats defined in the tables below. All of these codecs are provided as 1019 software implementations in the preferred Android implementation from the Android 1020 Open Source Project.</p> 1021 1022 <p><strong>Please note that neither Google nor the Open Handset Alliance make any 1023 representation that these codecs are unencumbered by third-party patents. 1024 Those intending to use this source code in hardware or software products are 1025 advised that implementations of this code, including in open source software 1026 or shareware, may require patent licenses from the relevant patent 1027 holders.</strong></p> 1028 1029 <p>Note that these tables do not list specific bitrate requirements for 1030 most video codecs because current device hardware does not necessarily support 1031 bitrates that map exactly to the required bitrates specified by the relevant 1032 standards. Instead, device implementations SHOULD support the highest bitrate 1033 practical on the hardware, up to the limits defined by the specifications.</p> 1034 <div style="page-break-before: always;"></div> 1035 <table> 1036 <tbody> 1037 1038 <tr> 1039 <th>Type</th> 1040 <th>Format / Codec</th> 1041 <th>Encoder</th> 1042 <th>Decoder</th> 1043 <th>Details</th> 1044 <th>File Type(s) / Container Formats</th> 1045 </tr> 1046 1047 <tr> 1048 <td rowspan="11">Audio</td> 1049 <td>MPEG-4 AAC Profile (AAC LC)</td> 1050 <td>REQUIRED for device implementations that include microphone hardware 1051 and define <code>android.hardware.microphone</code>.</td> 1052 <td style="text-align: center;">REQUIRED</td> 1053 <td rowspan="1"> Support for mono/stereo/5.0/5.1* content with standard sampling rates from 8 to 48 kHz.</td> 1054 <td rowspan="4"> 1055 <ul> 1056 <li>3GPP (.3gp)</li> 1057 <li>MPEG-4 (.mp4, .m4a)</li> 1058 <li>ADTS raw AAC (.aac, decode in Android 3.1+, encode in Android 4.0+, ADIF not supported)</li> 1059 <li>MPEG-TS (.ts, not seekable, Android 3.0+)</li> 1060 </ul> 1061 </td> 1062 </tr> 1063 1064 <tr> 1065 <td>MPEG-4 HE AAC Profile (AAC+)</td> 1066 <td>REQUIRED for device implementations that include microphone hardware and define android.hardware.microphone</td> 1067 <td style="text-align: center;">REQUIRED</td> 1068 <td>Support for mono/stereo/5.0/5.1* content with standard sampling rates from 16 to 48 kHz.</td> 1069 </tr> 1070 1071 <tr> 1072 <td>MPEG-4 HE AAC v2 Profile (enhanced AAC+)</td> 1073 <td> </td> 1074 <td style="text-align: center;">REQUIRED</td> 1075 <td>Support for mono/stereo/5.0/5.1* content with standard sampling rates from 16 to 48 kHz.</td> 1076 </tr> 1077 1078 <tr> 1079 <td>MPEG-4 Audio Object Type ER AAC ELD (Enhanced Low Delay AAC)</td> 1080 <td>REQUIRED for device implementations that include microphone hardware and define android.hardware.microphone</td> 1081 <td style="text-align: center;">REQUIRED</td> 1082 <td>Support for mono/stereo content with standard 1083 sampling rates from 16 to 48 kHz.</td> 1084 </tr> 1085 1086 <tr> 1087 <td>AMR-NB</td> 1088 <td>REQUIRED for device implementations that include microphone hardware 1089 and define <code>android.hardware.microphone</code>.</td> 1090 <td style="text-align: center;">REQUIRED</td> 1091 <td>4.75 to 12.2 kbps sampled @ 8kHz</td> 1092 <td>3GPP (.3gp) 1093 </td> 1094 </tr> 1095 1096 <tr> 1097 <td>AMR-WB</td> 1098 <td>REQUIRED for device implementations that include microphone hardware 1099 and define <code>android.hardware.microphone</code>.</td> 1100 <td style="text-align: center;">REQUIRED</td> 1101 <td>9 rates from 6.60 kbit/s to 23.85 kbit/s sampled @ 16kHz</td> 1102 <td>3GPP (.3gp)</td> 1103 </tr> 1104 1105 <tr> 1106 <td>FLAC</td> 1107 <td> </td> 1108 <td style="text-align: center;">REQUIRED<br/><small>(Android 3.1+)</small></td> 1109 <td>Mono/Stereo (no multichannel). Sample rates up to 48 kHz (but up to 44.1 1110 kHz is recommended on devices with 44.1 kHz output, as the 48 to 44.1 kHz 1111 downsampler does not include a low-pass filter). 16-bit recommended; 1112 no dither applied for 24-bit. 1113 </td> 1114 <td>FLAC (.flac) only</td> 1115 </tr> 1116 1117 <tr> 1118 <td>MP3</td> 1119 <td> </td> 1120 <td style="text-align: center;">REQUIRED</td> 1121 <td>Mono/Stereo 8-320Kbps constant (CBR) or variable bit-rate (VBR) 1122 </td> 1123 <td>MP3 (.mp3)</td> 1124 </tr> 1125 1126 <tr> 1127 <td>MIDI</td> 1128 <td> </td> 1129 <td style="text-align: center;">REQUIRED</td> 1130 <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> 1131 <td> 1132 <ul> 1133 <li>Type 0 and 1 (.mid, .xmf, .mxmf)</li> 1134 <li>RTTTL/RTX (.rtttl, .rtx)</li> 1135 <li>OTA (.ota)</li> 1136 <li>iMelody (.imy)</li> 1137 </ul> 1138 </td> 1139 </tr> 1140 1141 <tr> 1142 <td>Vorbis</td> 1143 <td> </td> 1144 <td style="text-align: center;">REQUIRED</td> 1145 <td> </td> 1146 <td> 1147 <ul> 1148 <li>Ogg (.ogg)</li> 1149 <li>Matroska (.mkv)</li> 1150 </ul> 1151 </td> 1152 </tr> 1153 1154 <tr> 1155 <td>PCM/WAVE</td> 1156 <td style="text-align: center;">REQUIRED</td> 1157 <td style="text-align: center;">REQUIRED</td> 1158 <td>8-bit and 16-bit linear PCM** (rates up to limit of hardware).Devices MUST support sampling rates 1159 for raw PCM recording at 8000,16000 and 44100 Hz frequencies</td> 1160 <td>WAVE (.wav)</td> 1161 </tr> 1162 1163 <tr> 1164 <td rowspan="5">Image</td> 1165 <td>JPEG</td> 1166 <td style="text-align: center;">REQUIRED</td> 1167 <td style="text-align: center;">REQUIRED</td> 1168 <td>Base+progressive</td> 1169 <td>JPEG (.jpg)</td> 1170 </tr> 1171 1172 <tr> 1173 <td>GIF</td> 1174 <td> </td> 1175 <td style="text-align: center;">REQUIRED</td> 1176 <td> </td> 1177 <td>GIF (.gif)</td> 1178 </tr> 1179 1180 <tr> 1181 <td>PNG</td> 1182 <td style="text-align: center;">REQUIRED</td> 1183 <td style="text-align: center;">REQUIRED</td> 1184 <td> </td> 1185 <td>PNG (.png)</td> 1186 </tr> 1187 1188 <tr> 1189 <td>BMP</td> 1190 <td> </td> 1191 <td style="text-align: center;">REQUIRED</td> 1192 <td> </td> 1193 <td>BMP (.bmp)</td> 1194 </tr> 1195 1196 1197 <tr> 1198 <td>WEBP</td> 1199 <td style="text-align: center;">REQUIRED</td> 1200 <td style="text-align: center;">REQUIRED</td> 1201 <td> </td> 1202 <td>WebP (.webp)</td> 1203 </tr> 1204 1205 <tr> 1206 <td rowspan="4">Video</td> 1207 <td>H.263</td> 1208 <td>REQUIRED for device implementations that include camera hardware 1209 and define <code>android.hardware.camera</code> or 1210 <code>android.hardware.camera.front</code>.</td> 1211 <td style="text-align: center;">REQUIRED</td> 1212 <td> </td> 1213 <td> 1214 <ul> 1215 <li>3GPP (.3gp)</li> 1216 <li>MPEG-4 (.mp4)</li> 1217 </ul> 1218 </td> 1219 </tr> 1220 1221 <tr> 1222 <td>H.264 AVC</td> 1223 <td>REQUIRED for device implementations that include camera hardware 1224 and define <code>android.hardware.camera</code> or 1225 <code>android.hardware.camera.front</code>.</td> 1226 <td style="text-align: center;">REQUIRED</td> 1227 <td>Baseline Profile (BP)</td> 1228 <td> 1229 <ul> 1230 <li>3GPP (.3gp)</li> 1231 <li>MPEG-4 (.mp4)</li> 1232 <li>MPEG-TS (.ts, AAC audio only, not seekable, Android 3.0+)</li> 1233 </ul> 1234 </td> 1235 </tr> 1236 1237 <tr> 1238 <td>MPEG-4 SP</td> 1239 <td> </td> 1240 <td style="text-align: center;">REQUIRED</td> 1241 <td> </td> 1242 <td>3GPP (.3gp)</td> 1243 </tr> 1244 1245 <tr> 1246 <td>VP8</td> 1247 <td style="text-align: center;">REQUIRED<br/><small>(Android 4.3+)</small></td> 1248 <td style="text-align: center;">REQUIRED<br/><small>(Android 2.3.3+)</small></td> 1249 <td> </td> 1250 <td><a href="http://www.webmproject.org/">WebM</a> (.webm) and Matroska (.mkv, Android 4.0+)***</td> 1251 </tr> 1252 1253 </tbody></table> 1254 <ul> 1255 <li>*Note: Only downmix of 5.0/5.1 content is required; recording or rendering more than 2 channels is optional.</li> 1256 <li>**Note: 16-bit linear PCM capture is mandatory. 8-bit linear PCM capture is not mandatory.</li> 1257 <li>***Note: Device implementations SHOULD support writing Matroska WebM files.</li> 1258 </ul> 1259 1260 <a name="section-5.2"></a><h3>5.2 Video Encoding</h3> 1261 <p>Android device implementations that include a rear-facing camera and declare 1262 <code>android.hardware.camera</code> SHOULD support the following H.264 video encoding 1263 profiles.</p> 1264 <table> 1265 <thead> 1266 <tr> 1267 <th> </th> 1268 <th>SD (Low quality)</th> 1269 <th>SD (High quality)</th> 1270 <th>HD (When supported by hardware)</th> 1271 </tr> 1272 </thead> 1273 <tbody> 1274 <tr> 1275 <th>Video resolution</th> 1276 <td>176 x 144 px</td> 1277 <td>480 x 360 px</td> 1278 <td>1280 x 720 px</td> 1279 </tr> 1280 <tr> 1281 <th>Video frame rate</th> 1282 <td>12 fps</td> 1283 <td>30 fps</td> 1284 <td>30 fps</td> 1285 </tr> 1286 <tr> 1287 <th>Video bitrate</th> 1288 <td>56 Kbps</td> 1289 <td>500 Kbps or higher</td> 1290 <td>2 Mbps or higher</td> 1291 </tr> 1292 <tr> 1293 <th>Audio codec</th> 1294 <td>AAC-LC</td> 1295 <td>AAC-LC</td> 1296 <td>AAC-LC</td> 1297 </tr> 1298 <tr> 1299 <th>Audio channels</th> 1300 <td>1 (mono)</td> 1301 <td>2 (stereo)</td> 1302 <td>2 (stereo)</td> 1303 </tr> 1304 <tr> 1305 <th>Audio bitrate</th> 1306 <td>24 Kbps</td> 1307 <td>128 Kbps</td> 1308 <td>192 Kbps</td> 1309 </tr> 1310 </tbody> 1311 </table> 1312 1313 <p>Android device implementations that include a rear-facing camera and declare 1314 <code>android.hardware.camera</code> SHOULD support the following VP8 video encoding profiles</p> 1315 <table> 1316 <thead> 1317 <tr> 1318 <th> </th> 1319 <th>SD (Low quality)</th> 1320 <th>SD (High quality)</th> 1321 <th>HD 720p <br/> (When supported by hardware)</th> 1322 <th>HD 1080p <br/>(When supported by hardware)</th> 1323 </tr> 1324 </thead> 1325 <tbody> 1326 <tr> 1327 <th>Video resolution</th> 1328 <td>320 x 180 px</td> 1329 <td>640 x 360 px</td> 1330 <td>1280 x 720 px</td> 1331 <td>1920 x 1080 px</td> 1332 </tr> 1333 <tr> 1334 <th>Video frame rate</th> 1335 <td>30 fps</td> 1336 <td>30 fps</td> 1337 <td>30 fps</td> 1338 <td>30 fps</td> 1339 </tr> 1340 <tr> 1341 <th>Video bitrate</th> 1342 <td>800 Kbps</td> 1343 <td>2 Mbps</td> 1344 <td>4 Mbps</td> 1345 <td>10 Mbps</td> 1346 </tr> 1347 </tbody> 1348 </table> 1349 1350 <a name="section-5.3"></a><h3>5.3 Video Decoding</h3> 1351 <p>Android device implementations SHOULD support the following VP8 and H.264 video decoding profiles.</p> 1352 <table> 1353 <thead> 1354 <tr> 1355 <th> </th> 1356 <th>SD (Low quality)</th> 1357 <th>SD (High quality)</th> 1358 <th>HD 720p <br/> (When supported by hardware)</th> 1359 <th>HD 1080p <br/>(When supported by hardware)</th> 1360 </tr> 1361 </thead> 1362 <tbody> 1363 <tr> 1364 <th>Video resolution</th> 1365 <td>320 x 180 px</td> 1366 <td>640 x 360 px</td> 1367 <td>1280 x 720 px</td> 1368 <td>1920 x 1080 px</td> 1369 </tr> 1370 <tr> 1371 <th>Video frame rate</th> 1372 <td>30 fps</td> 1373 <td>30 fps</td> 1374 <td>30 fps</td> 1375 <td>30 fps</td> 1376 </tr> 1377 <tr> 1378 <th>Video bitrate</th> 1379 <td>800 Kbps</td> 1380 <td>2 Mbps</td> 1381 <td>8 Mbps</td> 1382 <td>20 Mbps</td> 1383 </tr> 1384 </tbody> 1385 </table> 1386 1387 <a name="section-5.4"></a><h3>5.4. Audio Recording</h3> 1388 <p>When an application has used the <code>android.media.AudioRecord</code> API to 1389 start recording an audio stream, device implementations that include microphone 1390 hardware and declare <code>android.hardware.microphone</code> MUST sample and 1391 record audio with each of these behaviors:</p> 1392 <ul> 1393 <li>The device SHOULD exhibit approximately flat amplitude versus frequency 1394 characteristics; specifically, ±3 dB, from 100 Hz to 4000 Hz</li> 1395 <li>Audio input sensitivity SHOULD be set such that a 90 dB sound power level 1396 (SPL) source at 1000 Hz yields RMS of 2500 for 16-bit samples.</li> 1397 <li>PCM amplitude levels SHOULD linearly track input SPL changes over at least 1398 a 30 dB range from -18 dB to +12 dB re 90 dB SPL at the microphone.</li> 1399 <li>Total harmonic distortion SHOULD be less than 1% for 1Khz at 90 dB SPL input level.</li> 1400 </ul> 1401 <p>In addition to the above recording specifications, when an application has 1402 started recording an audio stream using the 1403 <code>android.media.MediaRecorder.AudioSource.VOICE_RECOGNITION</code> audio 1404 source:</p> 1405 <ul> 1406 <li>Noise reduction processing, if present, MUST be disabled.</li> 1407 <li>Automatic gain control, if present, MUST be disabled.</li> 1408 </ul> 1409 <p><b>Note:</b> while some of the requirements outlined above are stated as "SHOULD" 1410 for Android 4.3, the Compatibility Definition for a future version is planned 1411 to change these to "MUST". That is, these requirements are optional in Android 1412 4.3 but <b>will be required</b> by a future version. Existing and new devices 1413 that run Android 4.3 are <b>very strongly encouraged to meet 1414 these requirements in Android 4.3</b>, or they will not be able to attain 1415 Android compatibility when upgraded to the future version.</p> 1416 1417 <a name="section-5.5"></a><h3>5.5. Audio Latency</h3> 1418 <p>Audio latency is the time delay as an audio signal passes through a system. 1419 Many classes of 1420 applications rely on short latencies, to achieve real-time sound effects.</p> 1421 <p>For the purposes of this section:</p> 1422 <ul> 1423 <li>"output latency" is defined as the interval between when an application 1424 writes a frame of PCM-coded data and when the corresponding sound can be heard 1425 by an external listener or observed by a transducer</li> 1426 <li>"cold output latency" is defined as the output latency for the first frame, when 1427 the audio output system has been idle and powered down prior to the request</li> 1428 <li>"continuous output latency" is defined as the output latency for subsequent frames, 1429 after the device is already playing audio</li> 1430 <li>"input latency" is the interval between when an external sound is presented 1431 to the device and when an application reads the corresponding frame of PCM-coded data</li> 1432 <li>"cold input latency" is defined as the sum of lost input time 1433 and the input latency for the first frame, when 1434 the audio input system has been idle and powered down prior to the request</li> 1435 <li>"continuous input latency" is defined as the input latency for subsequent frames, 1436 while the device is already capturing audio</li> 1437 <li>"OpenSL ES PCM buffer queue API" is the set of PCM-related OpenSL ES APIs within Android NDK; 1438 see <i>NDK_root</i><code>/docs/opensles/index.html</code></li> 1439 </ul> 1440 <p>Per <a href="#section-5">Section 5</a>, 1441 all compatible device implementations MUST include at least one form of audio output. 1442 Device implementations SHOULD meet or exceed these output latency requirements:</p> 1443 <ul> 1444 <li>cold output latency of 100 milliseconds or less</li> 1445 <li>continuous output latency of 45 milliseconds or less</li> 1446 </ul> 1447 <p>If a device implementation meets the requirements of this section 1448 after any initial calibration 1449 when using the OpenSL ES PCM buffer queue API, 1450 for continuous output latency and cold output latency 1451 over at least one supported audio output device, it MAY 1452 report support for low-latency audio, by reporting the feature 1453 "android.hardware.audio.low-latency" via the 1454 <code>android.content.pm.PackageManager</code> class. [<a 1455 href="#resources37">Resources, 37</a>] Conversely, if the device 1456 implementation does not meet these requirements it MUST NOT report support for 1457 low-latency audio.</p> 1458 <p> 1459 Per <a href="#section-7.2.5">Section 7.2.5</a>, 1460 microphone hardware may be omitted by device implementations.</p> 1461 <p> 1462 Device implementations that include microphone 1463 hardware and declare <code>android.hardware.microphone</code> SHOULD 1464 meet these input audio latency requirements:</p> 1465 <ul> 1466 <li>cold input latency of 100 milliseconds or less</li> 1467 <li>continuous input latency of 50 milliseconds or less</li> 1468 </ul> 1469 1470 <a name="section-5.6"></a><h3>5.6. Network Protocols</h3> 1471 <p>Devices MUST support the media network protocols for audio and video playback 1472 as specified in the Android SDK documentation 1473 [<a href="#resources58">Resources, 58</a>]. Specifically, devices MUST support 1474 the following media network protocols:</p> 1475 <ul> 1476 <li>RTSP (RTP, SDP)</li> 1477 <li>HTTP(S) progressive streaming</li> 1478 <li>HTTP(S) Live Streaming draft protocol, Version 3 [<a href="#resources59">Resources, 59</a>]</li> 1479 </ul> 1480 <a name="section-6"></a><h2>6. Developer Tools and Options Compatibility</h2> 1481 1482 <a name="section-6.1"></a><h3>6.1 Developer Tools</h3> 1483 <p>Device implementations MUST support the Android Developer Tools provided in the Android SDK. 1484 Specifically, Android-compatible devices MUST be compatible with:</p> 1485 <ul> 1486 <li><b>Android Debug Bridge (known as adb)</b> [<a href="#resources33">Resources, 33</a>]<br/> 1487 Device implementations MUST support all <code>adb</code> functions as 1488 documented in the Android SDK. The device-side <code>adb</code> daemon MUST 1489 be inactive by default, and there MUST be a user-accessible mechanism to turn 1490 on the Android Debug Bridge.</li> 1491 <li>Android 4.3 includes support for secure adb. Secure adb enables adb on known authenticated hosts. 1492 Device implementations MUST support secure adb.</li> 1493 <li><b>Dalvik Debug Monitor Service (known as ddms)</b> [<a href="#resources33">Resources, 33</a>]<br/> 1494 Device implementations MUST support all <code>ddms</code> features as documented in the 1495 Android SDK. As <code>ddms</code> uses <code>adb</code>, support for 1496 <code>ddms</code> SHOULD be inactive by default, 1497 but MUST be supported whenever the user has activated the Android Debug 1498 Bridge, as above.</li> 1499 <li><b>Monkey</b> [<a href="#resources36">Resources, 36</a>]<br/> 1500 Device implementations MUST include the Monkey framework, and make it 1501 available for applications to use.</li> 1502 <li><b>SysTrace</b> [<a href="#resources33">Resources, 33</a>]<br/> 1503 Device implementations MUST support systrace tool as documented in the Android SDK. 1504 Systrace must be inactive by default, and there MUST be a user-accessible mechanism to turn 1505 on Systrace.</li> 1506 </ul> 1507 <p>Most Linux-based systems and Apple Macintosh systems recognize Android 1508 devices using the standard Android SDK tools, without additional support; 1509 however Microsoft Windows systems typically require a driver for new Android 1510 devices. (For instance, new vendor IDs and sometimes new device IDs require 1511 custom USB drivers for Windows systems.) If a device implementation is 1512 unrecognized by the <code>adb</code> tool as provided in the standard Android 1513 SDK, device implementers MUST provide Windows drivers allowing developers to 1514 connect to the device using the <code>adb</code> protocol. These drivers MUST 1515 be provided for Windows XP, Windows Vista, Windows 7, and Windows 8, in both 32-bit and 1516 64-bit versions.</p> 1517 1518 <a name="section-6.2"></a><h3>6.2 Developer Options</h3> 1519 <p>Android 4.3 includes support for developers to configure application development-related settings. 1520 Device implementations MUST honor the android.settings.APPLICATION_DEVELOPMENT_SETTINGS intent to show 1521 application development-related settings [<a href="#resources77">Resources, 77</a>]. The upstream Android 1522 implementation hides the Developer Options menu by default, and enables users to launch Developer Options 1523 after pressing seven (7) times on the Settings > About Device > Build Number menu item. Device implementations 1524 MUST provide a consistent experience for Developer Options. Specifically, device implementations MUST hide 1525 Developer Options by default and MUST provide a mechanism to enable Developer Options that is consistent with 1526 the upstream Android implementation.</p> 1527 1528 <a name="section-7"></a><h2>7. Hardware Compatibility</h2> 1529 <p>If a device includes a particular hardware component that has a 1530 corresponding API for third-party developers, the device implementation MUST 1531 implement that API as described in the Android SDK documentation. If an API in 1532 the SDK interacts with a hardware component that is stated to be optional and 1533 the device implementation does not possess that component:</p> 1534 <ul> 1535 <li>complete class definitions (as documented by the SDK) for the component's 1536 APIs MUST still be present</li> 1537 <li>the API's behaviors MUST be implemented as no-ops in some reasonable 1538 fashion</li> 1539 <li>API methods MUST return null values where permitted by the SDK 1540 documentation</li> 1541 <li>API methods MUST return no-op implementations of classes where null 1542 values are not permitted by the SDK documentation</li> 1543 <li>API methods MUST NOT throw exceptions not documented by the SDK 1544 documentation</li> 1545 </ul> 1546 <p>A typical example of a scenario where these requirements apply is the 1547 telephony API: even on non-phone devices, these APIs must be implemented as 1548 reasonable no-ops.</p> 1549 <p>Device implementations MUST accurately report accurate hardware configuration 1550 information via the <code>getSystemAvailableFeatures()</code> and 1551 <code>hasSystemFeature(String)</code> methods on the 1552 <code>android.content.pm.PackageManager</code> class. [<a 1553 href="#resources37">Resources, 37</a>]</p> 1554 1555 <a name="section-7.1"></a><h3>7.1. Display and Graphics</h3> 1556 <p>Android 4.3 includes facilities that automatically adjust application 1557 assets and UI layouts appropriately for the device, to ensure that third-party 1558 applications run well on a variety of hardware configurations [<a 1559 href="#resources38">Resources, 38</a>]. Devices MUST properly implement these 1560 APIs and behaviors, as detailed in this section.</p> 1561 1562 <p>The units referenced by the requirements in this section are defined as follows:</p> 1563 <ul> 1564 <li>"Physical diagonal size" is the distance in inches between two opposing 1565 corners of the illuminated portion of the display.</li> 1566 <li>"dpi" (meaning "dots per inch") is the number of pixels encompassed by a 1567 linear horizontal or vertical span of 1". Where dpi values are listed, both 1568 horizontal and vertical dpi must fall within the range.</li> 1569 <li>"Aspect ratio" is the ratio of the longer dimension of the screen to the 1570 shorter dimension. For example, a display of 480x854 pixels would be 854 / 480 1571 = 1.779, or roughly "16:9".</li> 1572 <li>A "density-independent pixel" or ("dp") is the virtual pixel unit normalized to a 1573 160 dpi screen, calculated as: 1574 <code>pixels = dps * (density / 160)</code>.</li> 1575 </ul> 1576 1577 1578 <a name="section-7.1.1"></a><h4>7.1.1. Screen Configuration</h4> 1579 1580 <p style="font-weight:bold;">Screen Size</p> 1581 <p>The Android UI framework supports a variety of different screen sizes, and 1582 allows applications to query the device screen size (aka "screen layout") via 1583 <code>android.content.res.Configuration.screenLayout</code> with the 1584 <code>SCREENLAYOUT_SIZE_MASK</code>. Device implementations MUST report the 1585 correct screen size as defined in the Android SDK documentation 1586 [<a href="#resources38">Resources, 38</a>] and determined by the upstream 1587 Android platform. Specifically, device implementations must report the correct 1588 screen size according to the following logical density-independent pixel (dp) 1589 screen dimensions.</p> 1590 <ul> 1591 <li>Devices MUST have screen sizes of at least 426 dp x 320 dp ('small')</li> 1592 <li>Devices that report screen size 'normal' MUST have screen sizes of at least 1593 480 dp x 320 dp</li> 1594 <li>Devices that report screen size 'large' MUST have screen sizes of at least 1595 640 dp x 480 dp</li> 1596 <li>Devices that report screen size 'xlarge' MUST have screen sizes of at least 1597 960 dp x 720 dp</li> 1598 </ul> 1599 <p>In addition, devices MUST have screen sizes of at least 2.5 inches in 1600 physical diagonal size.</p> 1601 1602 <p>Devices MUST NOT change their reported screen size at any time.</p> 1603 <p>Applications optionally indicate which screen sizes they support via the 1604 <code><supports-screens></code> attribute in the AndroidManifest.xml 1605 file. Device implementations MUST correctly honor applications' stated support 1606 for small, normal, large, and xlarge screens, as described in the Android 1607 SDK documentation.</p> 1608 1609 <p style="font-weight:bold;">Screen Aspect Ratio</p> 1610 <p>The aspect ratio MUST be between 1.3333 (4:3) and 1.85 (16:9).</p> 1611 1612 <p style="font-weight:bold;">Screen Density</p> 1613 <p>The Android UI framework defines a set of standard logical densities to 1614 help application developers target application resources. Device 1615 implementations MUST report one of the following logical Android framework 1616 densities through the <code>android.util.DisplayMetrics</code> APIs, and MUST 1617 execute applications at this standard density. 1618 <ul> 1619 <li>120 dpi, known as 'ldpi'</li> 1620 <li>160 dpi, known as 'mdpi'</li> 1621 <li>213 dpi, known as 'tvdpi'</li> 1622 <li>240 dpi, known as 'hdpi'</li> 1623 <li>320 dpi, known as 'xhdpi'</li> 1624 <li>480 dpi, known as 'xxhdpi'</li> 1625 <li>640 dpi, known as 'xxxhdpi'</li> 1626 </ul> 1627 Device implementations SHOULD define the standard Android framework density 1628 that is numerically closest to the physical density of the screen, unless that 1629 logical density pushes the reported screen size below the minimum supported. 1630 If the standard Android framework density that is numerically closest to the 1631 physical density results in a screen size that is smaller than the smallest 1632 supported compatible screen size (320 dp width), device implementations SHOULD 1633 report the next lowest standard Android framework density.</p> 1634 1635 <a name="section-7.1.2"></a><h4>7.1.2. Display Metrics</h4> 1636 <p>Device implementations MUST report correct values for all display metrics 1637 defined in <code>android.util.DisplayMetrics</code> [<a 1638 href="#resources39">Resources, 39</a>].</p> 1639 1640 <a name="section-7.1.3"></a><h4>7.1.3. Screen Orientation</h4> 1641 <p>Devices MUST support dynamic orientation by applications to 1642 either portrait or landscape screen orientation. That is, the device must 1643 respect the application's request for a specific screen orientation. Device 1644 implementations MAY select either portrait or landscape orientation as the 1645 default.</p> 1646 <p>Devices MUST report the correct value for the device's current orientation, 1647 whenever queried via the android.content.res.Configuration.orientation, 1648 android.view.Display.getOrientation(), or other APIs.</p> 1649 <p>Devices MUST NOT change the reported screen size or density when changing 1650 orientation.</p> 1651 <p>Devices MUST report which screen orientations they support ( 1652 <code>android.hardware.screen.portrait</code> and/or 1653 <code>android.hardware.screen.landscape</code>) and MUST report at least one 1654 supported orientation. For example, a device with a fixed-orientation 1655 landscape screen, such as a television or laptop, MUST only report 1656 <code>android.hardware.screen.landscape</code>.</p> 1657 1658 <a name="section-7.1.4"></a><h4>7.1.4. 2D and 3D Graphics Acceleration</h4> 1659 <p>Device implementations MUST support both OpenGL ES 1.0 and 2.0, as embodied 1660 and detailed in the Android SDK documentations. Device implementations SHOULD support 1661 OpenGL ES 3.0 on devices capable of supporting OpenGL ES 3.0. 1662 Device implementations MUST also support Android Renderscript, as detailed in the Android SDK 1663 documentation [<a href="#resources08">Resources, 8</a>].</p> 1664 <p>Device implementations MUST also correctly identify themselves as 1665 supporting OpenGL ES 1.0, OpenGL ES 2.0, or OpenGL ES 3.0. That is:</p> 1666 <ul> 1667 <li>The managed APIs (such as via the <code>GLES10.getString()</code> method) 1668 MUST report support for OpenGL ES 1.0 and OpenGL ES 2.0 </li> 1669 <li>The native C/C++ OpenGL APIs (that is, those available to apps via 1670 libGLES_v1CM.so, libGLES_v2.so, or libEGL.so) MUST report support for 1671 OpenGL ES 1.0 and OpenGL ES 2.0.</li> 1672 <li>Device implementations that declare support for OpenGL ES 3.0 MUST support 1673 OpenGL ES 3.0 managed APIs and include support for native C/C++ APIs. On device 1674 implementations that declare support for OpenGL ES 3.0, libGLESv2.so MUST export the OpenGL ES 3.0 1675 function symbols in addition to the OpenGL ES 2.0 function symbols. 1676 </li> 1677 </ul> 1678 1679 <p>Device implementations MAY implement any desired OpenGL ES extensions. 1680 However, device implementations MUST report via the OpenGL ES managed and 1681 native APIs all extension strings that they do support, and conversely MUST 1682 NOT report extension strings that they do not support.</p> 1683 <p>Note that Android 4.3 includes support for applications to optionally 1684 specify that they require specific OpenGL texture compression formats. These 1685 formats are typically vendor-specific. Device implementations are not required 1686 by Android 4.3 to implement any specific texture compression format. However, 1687 they SHOULD accurately report any texture compression formats that they do 1688 support, via the <code>getString()</code> method in the OpenGL API.</p> 1689 1690 <p>Android 4.3 includes a mechanism for applications to declare that they 1691 wanted to enable hardware acceleration for 2D graphics at the Application, 1692 Activity, Window or View level through the use of a manifest tag 1693 <code>android:hardwareAccelerated</code> or direct API calls 1694 [<a href="#resources09">Resources, 9</a>].</p> 1695 <p>In Android 4.3, device implementations MUST enable hardware acceleration by 1696 default, and MUST disable hardware acceleration if the developer so requests 1697 by setting <code>android:hardwareAccelerated="false"</code> or disabling 1698 hardware acceleration directly through the Android View APIs.</p> 1699 <p>In addition, device implementations MUST exhibit behavior consistent with the 1700 Android SDK documentation on hardware acceleration 1701 [<a href="#resources09">Resources, 9</a>].</p> 1702 <p>Android 4.3 includes a <code>TextureView</code> object that lets developers 1703 directly integrate hardware-accelerated OpenGL ES textures as rendering targets 1704 in a UI hierarchy. Device implementations MUST support the <code>TextureView 1705 </code> API, and MUST exhibit consistent behavior with the upstream Android 1706 implementation.</p> 1707 <p>Android 4.3 includes support for <code>EGL_ANDROID_RECORDABLE</code>, a EGLConfig attribute 1708 that indicates whether the EGLConfig supports rendering to an ANativeWindow that records images to a video. 1709 Device implementations MUST support <code>EGL_ANDROID_RECORDABLE</code> extension [<a href="#resources79">Resources, 79</a>].</p> 1710 1711 <a name="section-7.1.5"></a><h4>7.1.5. Legacy Application Compatibility Mode</h4> 1712 <p>Android 4.3 specifies a "compatibility mode" in which the framework 1713 operates in an 'normal' screen size equivalent (320dp width) mode for the benefit 1714 of legacy applications not developed for old versions of Android that pre-date 1715 screen-size independence. Device implementations MUST include support for legacy 1716 application compatibility mode as implemented by the upstream Android open source 1717 code. That is, device implementations MUST NOT alter the triggers or thresholds at 1718 which compatibility mode is activated, and MUST NOT alter the behavior of the 1719 compatibility mode itself.</p> 1720 1721 <a name="section-7.1.6"></a><h4>7.1.6. Screen Types</h4> 1722 <p>Device implementation screens are classified as one of two types:</p> 1723 <ul> 1724 <li>Fixed-pixel display implementations: the screen is a single panel that supports only a 1725 single pixel width and height. Typically the screen is physically integrated with 1726 the device. Examples include mobile phones, tablets, and so on.</li> 1727 <li>Variable-pixel display implementations: the device implementation either has no 1728 embedded screen and includes a video output port such as VGA, HDMI or a wireless port 1729 for display, or has an embedded screen that can change pixel dimensions. Examples 1730 include televisions, set-top boxes, and so on.</li> 1731 </ul> 1732 <p style="font-weight: bold;">Fixed-Pixel Device Implementations</p> 1733 <p>Fixed-pixel device implementations MAY use screens of any pixel dimensions, provided 1734 that they meet the requirements defined this Compatibility Definition.</p> 1735 <p>Fixed-pixel implementations MAY include a video output port for use with an 1736 external display. However, if that display is ever used for running apps, the 1737 device MUST meet the following requirements:</p> 1738 <ul> 1739 <li>The device MUST report the same screen configuration and display metrics, as detailed 1740 in Sections 7.1.1 and 7.1.2, as the fixed-pixel display.</li> 1741 <li>The device MUST report the same logical density as the fixed-pixel display.</li> 1742 <li>The device MUST report screen dimensions that are the same as, or very close to, 1743 the fixed-pixel display.</li> 1744 </ul> 1745 <p>For example, a tablet that is 7" diagonal size with a 1024x600 pixel resolution is 1746 considered a fixed-pixel large mdpi display implementation. If it contains a video 1747 output port that displays at 720p or 1080p, the device implementation MUST scale the output so that 1748 applications are only executed in a large mdpi window, regardless of whether the fixed-pixel display 1749 or video output port is in use.</p> 1750 1751 <p style="font-weight: bold;">Variable-Pixel Device Implementations</p> 1752 <p>Variable-pixel device implementations MUST support one or both of 1280x720, 1753 or 1920x1080 (that is, 720p or 1080p). Device implementations with 1754 variable-pixel displays MUST NOT support any other screen configuration or 1755 mode. Device implementations with variable-pixel screens MAY change screen 1756 configuration or mode at runtime or boot-time. For example, a user of a 1757 set-top box may replace a 720p display with a 1080p display, and the device 1758 implementation may adjust accordingly.</p> 1759 1760 <p>Additionally, variable-pixel device implementations MUST report the following 1761 configuration buckets for these pixel dimensions:</p> 1762 <ul> 1763 <li>1280x720 (also known as 720p): 'large' screen size, 'tvdpi' (213 dpi) 1764 density</li> 1765 <li>1920x1080 (also known as 1080p): 'large' screen size, 'xhdpi' (320 dpi) 1766 density</li> 1767 </ul> 1768 <p>For clarity, device implementations with variable pixel dimensions are 1769 restricted to 720p or 1080p in Android 4.3, and MUST be configured to report 1770 screen size and density buckets as noted above.</p> 1771 1772 <a name="section-7.1.7"></a><h4>7.1.7. Screen Technology</h4> 1773 <p>The Android platform includes APIs that allow applications to render rich 1774 graphics to the display. Devices MUST support all of these APIs as defined by 1775 the Android SDK unless specifically allowed in this document. Specifically:</p> 1776 <ul> 1777 <li>Devices MUST support displays capable of rendering 16-bit color graphics and 1778 SHOULD support displays capable of 24-bit color graphics.</li> 1779 <li>Devices MUST support displays capable of rendering animations.</li> 1780 <li>The display technology used MUST have a pixel aspect ratio (PAR) between 1781 0.9 and 1.1. That is, the pixel aspect ratio MUST be near square (1.0) with 1782 a 10% tolerance.</li> 1783 </ul> 1784 <a name="section-7.1.8"></a><h4>7.1.8. External Displays</h4> 1785 <p>Android 4.3 includes support for secondary display to enable media sharing capabilities and 1786 developer APIs for accessing external displays. If a device supports an external display either via 1787 a wired, wireless or an embedded additional display connection then the device implementation MUST 1788 implement the display manager API as described in the Android SDK documentation [<a href="#resources75">Resources, 75</a>]. 1789 Device implementations that support secure video output and are capable of supporting secure surfaces MUST declare support 1790 for <code>Display.FLAG_SECURE</code>. Specifically, device implementations that declare support for <code>Display.FLAG_SECURE</code>, 1791 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 1792 Android open source implementation includes support for wireless (Miracast) and wired (HDMI) displays that satisfies this requirement.</p> 1793 1794 <a name="section-7.2"></a><h3>7.2. Input Devices</h3> 1795 <a name="section-7.2.1"></a><h4>7.2.1. Keyboard</h4> 1796 <p>Device implementations:</p> 1797 <ul> 1798 <li>MUST include support for the Input Management Framework (which allows third 1799 party developers to create Input Management Engines - i.e. soft keyboard) as 1800 detailed at <a href="http://developer.android.com">http://developer.android.com</a> 1801 </li> 1802 <li>MUST provide at least one soft keyboard implementation (regardless of whether 1803 a hard keyboard is present)</li> 1804 <li>MAY include additional soft keyboard implementations</li> 1805 <li>MAY include a hardware keyboard</li> 1806 <li>MUST NOT include a hardware keyboard that does not match one of the 1807 formats specified in <code>android.content.res.Configuration.keyboard</code> 1808 [<a href="#resources40">Resources, 40</a>] (that is, QWERTY, or 12-key)</li> 1809 </ul> 1810 <a name="section-7.2.2"></a><h4>7.2.2. Non-touch Navigation</h4> 1811 <p>Device implementations:</p> 1812 <ul> 1813 <li>MAY omit a non-touch navigation option (that is, may omit a trackball, d-pad, 1814 or wheel)</li> 1815 <li>MUST report the correct value for 1816 <code>android.content.res.Configuration.navigation</code> 1817 [<a href="#resources40">Resources, 40</a>]</li> 1818 <li>MUST provide a reasonable alternative user interface mechanism for the 1819 selection and editing of text, compatible with Input Management Engines. The 1820 upstream Android open source implementation includes a selection mechanism suitable 1821 for use with devices that lack non-touch navigation inputs.</li> 1822 </ul> 1823 <a name="section-7.2.3"></a><h4>7.2.3. Navigation keys</h4> 1824 <p>The Home, Menu and Back functions are essential to the Android navigation 1825 paradigm. Device implementations MUST make these functions available to the 1826 user at all times when running applications. These functions MAY be implemented 1827 via dedicated physical buttons (such as mechanical or capacitive touch buttons), 1828 or MAY be implemented using dedicated software keys, gestures, touch panel, etc. 1829 Android 4.3 supports both implementations.</p> 1830 1831 <p>Android 4.3 includes support for assist action [<a href="#resources63">Resources, 63</a>]. 1832 Device implementations MUST make the assist action available to the user at all times when running applications. 1833 This function MAY be implemented via hardware or software keys.</p> 1834 1835 <p>Device implementations MAY use a distinct portion of the screen to display 1836 the navigation keys, but if so, MUST meet these requirements:</p> 1837 1838 <ul> 1839 <li>Device implementation navigation keys MUST use a distinct portion of the 1840 screen, not available to applications, and MUST NOT obscure or otherwise 1841 interfere with the portion of the screen available to applications.</li> 1842 <li>Device implementations MUST make available a portion of the display to 1843 applications that meets the requirements defined in 1844 <a href="section-7.1.1">Section 7.1.1</a>.</li> 1845 <li>Device implementations MUST display the navigation keys when applications 1846 do not specify a system UI mode, or specify 1847 <code>SYSTEM_UI_FLAG_VISIBLE</code>.</li> 1848 <li>Device implementations MUST present the navigation keys in an unobtrusive 1849 "low profile" (eg. dimmed) mode when applications specify 1850 <code>SYSTEM_UI_FLAG_LOW_PROFILE</code>.</li> 1851 <li>Device implementations MUST hide the navigation keys when applications 1852 specify <code>SYSTEM_UI_FLAG_HIDE_NAVIGATION</code>.</li> 1853 <li>Device implementation MUST present a Menu key to applications when 1854 targetSdkVersion <= 10 and SHOULD NOT present a Menu key when the 1855 targetSdkVersion > 10.</li> 1856 </ul> 1857 <a name="section-7.2.4"></a><h4>7.2.4. Touchscreen input</h4> 1858 <p>Device implementations SHOULD have a pointer input system of some kind (either mouse-like, or touch). However, if a device 1859 implementation does not support a pointer input system, it MUST NOT report the <code>android.hardware.touchscreen</code> or 1860 <code>android.hardware.faketouch</code> feature constant. Device implementations that do include a pointer input system:</p> 1861 <ul> 1862 <li>SHOULD support fully independently tracked pointers, if the device input system supports multiple pointers</li> 1863 <li>MUST report the value of <code>android.content.res.Configuration.touchscreen</code> [<a href="#resources40">Resources, 40</a>] 1864 corresponding to the type of the specific touchscreen on the device</li> 1865 </ul> 1866 1867 <p>Android 4.3 includes support for a variety of touch screens, touch pads, and fake touch input devices. 1868 Touch screen based device implementations are associated with a display [<a href="#resources81">Resources, 81</a>] 1869 such that the user has the impression of directly manipulating items on screen. Since the user is directly touching the screen, 1870 the system does not require any additional affordances to indicate the objects being manipulated. 1871 In contrast, a fake touch interface provides a user input system that approximates a subset of touchscreen capabilities. 1872 For example, a mouse or remote control that drives an on-screen cursor approximates touch, but requires the user to first 1873 point or focus then click. Numerous input devices like the mouse, trackpad, gyro-based air mouse, gyro-pointer, joystick, 1874 and multi-touch trackpad can support fake touch interactions. Android 4.0 includes the feature constant <code>android.hardware.faketouch</code>, 1875 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 1876 input (including basic gesture support), and indicates that the device supports an emulated subset of touchscreen 1877 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> 1878 1879 <p>Device implementations MUST report the correct feature corresponding to the type of input used. Device implementations that 1880 include a touchscreen (single-touch or better) MUST report the platform feature constant <code>android.hardware.touchscreen</code>. 1881 Device implementations that report the platform feature constant <code>android.hardware.touchscreen</code> MUST also report the platform feature constant 1882 <code>android.hardware.faketouch</code>. Device implementations that do not include a touchscreen (and rely on a pointer device only) MUST NOT report any 1883 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> 1884 1885 <a name="section-7.2.5"></a><h4>7.2.5. Fake touch input</h4> 1886 <p>Device implementations that declare support for <code>android.hardware.faketouch</code></p> 1887 <ul> 1888 <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> 1889 <li> MUST report touch event with the action code [<a href="#resources80">Resources, 80</a>] that specifies the state change 1890 that occurs on the pointer going <code>down</code> or <code>up</code> on the screen [<a href="#resources80">Resources, 80</a>] </li> 1891 <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> 1892 <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 1893 within a time threshold, which allows users to emulate double tap on an object on the screen [<a href="#resources80">Resources, 80</a>]</li> 1894 <li>MUST support pointer <code>down</code> on an arbitrary point on the screen, pointer move to any other arbitrary point on the screen, 1895 followed by a pointer <code>up</code>, which allows users to emulate a touch drag</li> 1896 <li> MUST support pointer <code>down</code> then allow users to quickly move the object to a different position on the screen 1897 and then pointer <code>up</code> on the screen, which allows users to fling an object on the screen</li> 1898 </ul> 1899 1900 <p>Devices that declare support for <code>android.hardware.faketouch.multitouch.distinct</code> MUST meet the requirements for 1901 faketouch above, and MUST also support distinct tracking of two or more independent pointer inputs.</p> 1902 1903 <a name="section-7.2.6"></a><h4>7.2.6. Microphone</h4> 1904 <p>Device implementations MAY omit a microphone. However, if a device 1905 implementation omits a microphone, it MUST NOT report the 1906 <code>android.hardware.microphone</code> feature constant, and must implement 1907 the audio recording API as no-ops, per <a href="section-7">Section 7</a>. 1908 Conversely, device implementations that do possess a microphone:</p> 1909 <ul> 1910 <li>MUST report the <code>android.hardware.microphone</code> feature constant</li> 1911 <li>SHOULD meet the audio quality requirements in <a href="section-5.4">Section 5.4</a></li> 1912 <li>SHOULD meet the audio latency requirements in <a href="section-5.5">Section 5.5</a></li> 1913 </ul> 1914 1915 <a name="section-7.3"></a><h3>7.3. Sensors</h3> 1916 <p>Android 4.3 includes APIs for accessing a variety of sensor types. Devices 1917 implementations generally MAY omit these sensors, as provided for in the 1918 following subsections. If a device includes a particular sensor type that has a 1919 corresponding API for third-party developers, the device implementation MUST 1920 implement that API as described in the Android SDK documentation. For example, 1921 device implementations:</p> 1922 <ul> 1923 <li>MUST accurately report the presence or absence of sensors per the 1924 <code>android.content.pm.PackageManager</code> class. [<a 1925 href="#resources37">Resources, 37</a>]</li> 1926 <li>MUST return an accurate list of supported sensors via the 1927 <code>SensorManager.getSensorList()</code> and similar methods</li> 1928 <li>MUST behave reasonably for all other sensor APIs (for example, by 1929 returning true or false as appropriate when applications attempt to register 1930 listeners, not calling sensor listeners when the corresponding sensors are not 1931 present; etc.)</li> 1932 <li>MUST report all sensor measurements using the relevant International System 1933 of Units (i.e. metric) values for each sensor type as defined in the Android SDK 1934 documentation [<a href="#resources41">Resources, 41</a>]</li> 1935 </ul> 1936 <p>The list above is not comprehensive; the documented behavior of the Android 1937 SDK is to be considered authoritative.</p> 1938 <p>Some sensor types are synthetic, meaning they can be derived from data 1939 provided by one or more other sensors. (Examples include the orientation 1940 sensor, and the linear acceleration sensor.) Device implementations SHOULD 1941 implement these sensor types, when they include the prerequisite physical 1942 sensors.</p> 1943 <p>The Android 4.3 includes a notion of a "streaming" sensor, which is 1944 one that returns data continuously, rather than only when the data changes. 1945 Device implementations MUST continuously provide periodic data samples for any 1946 API indicated by the Android 4.3 SDK documentation to be a streaming 1947 sensor. Note that the device implementations MUST ensure that the sensor stream must not 1948 prevent the device CPU from entering a suspend state or waking up from a suspend state.</p> 1949 1950 <a name="section-7.3.1"></a><h4>7.3.1. Accelerometer</h4> 1951 <p>Device implementations SHOULD include a 3-axis accelerometer. If a device 1952 implementation does include a 3-axis accelerometer, it:</p> 1953 <ul> 1954 <li>SHOULD be able to deliver events at 120 Hz or greater. Note that while the 1955 accelerometer frequency above is stated as "SHOULD" for Android 4.3, the Compatibility Definition 1956 for a future version is planned to change these to "MUST". That is, these standards are 1957 optional in Android 4.3 but <b>will be required</b> in future versions. Existing and 1958 new devices that run Android 4.3 are <b>very strongly encouraged to meet these requirements 1959 in Android 4.3</b> so they will be able to upgrade to the future platform releases 1960 </li> 1961 <li>MUST comply with the Android sensor coordinate system as detailed 1962 in the Android APIs (see [<a href="#resources41">Resources, 41</a>])</li> 1963 <li>MUST be capable of measuring from freefall up to twice gravity (2g) or 1964 more on any three-dimensional vector</li> 1965 <li>MUST have 8-bits of accuracy or more</li> 1966 <li>MUST have a standard deviation no greater than 0.05 m/s^2</li> 1967 </ul> 1968 <a name="section-7.3.2"></a><h4>7.3.2. Magnetometer</h4> 1969 <p>Device implementations SHOULD include a 3-axis magnetometer (i.e. compass.) 1970 If a device does include a 3-axis magnetometer, it:</p> 1971 <ul> 1972 <li>MUST be able to deliver events at 10 Hz or greater</li> 1973 <li>MUST comply with the Android sensor coordinate system as detailed 1974 in the Android APIs (see [<a href="#resources41">Resources, 41</a>]).</li> 1975 <li>MUST be capable of sampling a range of field strengths adequate to cover the 1976 geomagnetic field</li> 1977 <li>MUST have 8-bits of accuracy or more</li> 1978 <li>MUST have a standard deviation no greater than 0.5 µT</li> 1979 </ul> 1980 <a name="section-7.3.3"></a><h4>7.3.3. GPS</h4> 1981 <p>Device implementations SHOULD include a GPS receiver. If a device 1982 implementation does include a GPS receiver, it SHOULD include 1983 some form of "assisted GPS" technique to minimize GPS lock-on time.</p> 1984 <a name="section-7.3.4"></a><h4>7.3.4. Gyroscope</h4> 1985 <p>Device implementations SHOULD include a gyroscope (i.e. angular change 1986 sensor.) Devices SHOULD NOT include a gyroscope sensor unless a 3-axis 1987 accelerometer is also included. If a device implementation includes a 1988 gyroscope, it:</p> 1989 <ul> 1990 <li>MUST be temperature compensated</li> 1991 <li>MUST be capable of measuring orientation changes up to 5.5*Pi 1992 radians/second (that is, approximately 1,000 degrees per second)</li> 1993 <li>SHOULD be able to deliver events at 200 Hz or greater. Note that while the 1994 gyroscope frequency above is stated as "SHOULD" for Android 4.3, the Compatibility Definition 1995 for a future version is planned to change these to "MUST". That is, these standards are 1996 optional in Android 4.3 but <b>will be required</b> in future versions. Existing and 1997 new devices that run Android 4.3 are <b>very strongly encouraged to meet these requirements 1998 in Android 4.3</b> so they will be able to upgrade to the future platform releases 1999 </li> 2000 <li>MUST have 12-bits of accuracy or more</li> 2001 <li>MUST have a variance no greater than 1e-7 rad^2 / s^2 per Hz (variance per Hz, or rad^2 / s). 2002 The variance is allowed to vary with the sampling rate, but must be constrained by this value. 2003 In other words, if you measure the variance of the gyro at 1 Hz sampling rate it should be no 2004 greater than 1e-7 rad^2/s^2. </li> 2005 <li>MUST have timestamps as close to when the hardware event happened as possible. The constant latency must be removed.</li> 2006 </ul> 2007 <a name="section-7.3.5"></a><h4>7.3.5. Barometer</h4> 2008 <p>Device implementations MAY include a barometer (i.e. ambient air pressure 2009 sensor.) If a device implementation includes a barometer, it:</p> 2010 <ul> 2011 <li>MUST be able to deliver events at 5 Hz or greater</li> 2012 <li>MUST have adequate precision to enable estimating altitude</li> 2013 <li>MUST be temperature compensated</li> 2014 </ul> 2015 <a name="section-7.3.6"></a><h4>7.3.6. Thermometer</h4> 2016 <p>Device implementations MAY but SHOULD NOT include a thermometer (i.e. 2017 temperature sensor.) If a device implementation does include a thermometer, it 2018 MUST measure the temperature of the device CPU. It MUST NOT measure any other 2019 temperature. (Note that this sensor type is deprecated in the Android 4.3 2020 APIs.)</p> 2021 <a name="section-7.3.7"></a><h4>7.3.7. Photometer</h4> 2022 <p>Device implementations MAY include a photometer (i.e. ambient light 2023 sensor.)</p> 2024 <a name="section-7.3.8"></a><h4>7.3.8. Proximity Sensor</h4> 2025 <p>Device implementations MAY include a proximity sensor. If a device 2026 implementation does include a proximity sensor, it MUST measure the proximity 2027 of an object in the same direction as the screen. That is, the proximity 2028 sensor MUST be oriented to detect objects close to the screen, as the 2029 primary intent of this sensor type is to detect a phone in use by the 2030 user. If a device implementation includes a proximity sensor with any other 2031 orientation, it MUST NOT be accessible through this API. If a device 2032 implementation has a proximity sensor, it MUST be have 1-bit of accuracy or 2033 more.</p> 2034 2035 <a name="section-7.4"></a><h3>7.4. Data Connectivity</h3> 2036 <a name="section-7.4.1"></a><h4>7.4.1. Telephony</h4> 2037 <p>"Telephony" as used by the Android 4.3 APIs and this document refers 2038 specifically to hardware related to placing voice calls and sending SMS 2039 messages via a GSM or CDMA network. While these voice calls may or may not be 2040 packet-switched, they are for the purposes of Android 4.3 considered 2041 independent of any data connectivity that may be implemented using the same 2042 network. In other words, the Android "telephony" functionality and APIs refer 2043 specifically to voice calls and SMS; for instance, device implementations that 2044 cannot place calls or send/receive SMS messages MUST NOT report the 2045 "android.hardware.telephony" feature or any sub-features, regardless of 2046 whether they use a cellular network for data connectivity.</p> 2047 <p>Android 4.3 MAY be used on devices that do not include telephony hardware. 2048 That is, Android 4.3 is compatible with devices that are not phones. 2049 However, if a device implementation does include GSM or CDMA telephony, it 2050 MUST implement full support for the API for that technology. Device 2051 implementations that do not include telephony hardware MUST implement the full 2052 APIs as no-ops.</p> 2053 <a name="section-7.4.2"></a><h4>7.4.2. IEEE 802.11 (WiFi)</h4> 2054 <p>Android 4.3 device implementations SHOULD include support for one or more 2055 forms of 802.11 (b/g/a/n, etc.) If a device implementation does include 2056 support for 802.11, it MUST implement the corresponding Android API.</p> 2057 <p>Device implementations MUST implement the multicast API as described in 2058 the SDK documentation [<a href="#resources62">Resources, 62</a>]. Device 2059 implementations that do include Wifi support MUST support multicast DNS (mDNS). 2060 Device implementations MUST NOT filter mDNS packets (224.0.0.251) at any time 2061 of operation including when the screen is not in an active state.</p> 2062 2063 <a name="section-7.4.2.1"></a><h4>7.4.2.1. WiFi Direct</h4> 2064 <p>Device implementations SHOULD include support for Wifi direct (Wifi peer-to-peer). 2065 If a device implementation does include support for Wifi direct, it MUST implement the corresponding 2066 Android API as described in the SDK documentation [<a href="#resources68">Resources, 68</a>]. 2067 If a device implementation includes support for Wifi direct, then it:</p> 2068 <ul> 2069 <li>MUST support regular Wifi operation</li> 2070 <li>SHOULD support concurrent wifi and wifi Direct operation</li> 2071 </ul> 2072 2073 <a name="section-7.4.3"></a><h4>7.4.3. Bluetooth</h4> 2074 <p>Device implementations SHOULD include a Bluetooth transceiver. Device 2075 implementations that do include a Bluetooth transceiver MUST enable the 2076 RFCOMM-based Bluetooth API as described in the SDK documentation and declare 2077 hardware feature android.hardware.bluetooth [<a href="#resources42">Resources, 42</a>]. 2078 Device implementations SHOULD implement relevant Bluetooth profiles, such as A2DP, AVRCP, OBEX, etc. as 2079 appropriate for the device.</p> 2080 2081 <p>Device implementations that do include support for Bluetooth GATT (generic attribute profile) 2082 to enable communication with Bluetooth Smart or Smart Ready devices MUST enable the 2083 GATT-based Bluetooth API as described in the SDK documentation and declare hardware feature 2084 android.hardware.bluetooth_le [<a href="#resources42">Resources, 42</a>].</p> 2085 2086 <a name="section-7.4.4"></a><h4>7.4.4. Near-Field Communications</h4> 2087 <p>Device implementations SHOULD include a transceiver and related hardware 2088 for Near-Field Communications (NFC). If a device implementation does include 2089 NFC hardware, then it:</p> 2090 <ul> 2091 <li>MUST report the android.hardware.nfc feature from the 2092 <code>android.content.pm.PackageManager.hasSystemFeature()</code> method. 2093 [<a href="#resources37">Resources, 37</a>]</li> 2094 <li>MUST be capable of reading and writing NDEF messages via the following NFC 2095 standards: 2096 <ul> 2097 <li>MUST be capable of acting as an NFC Forum reader/writer 2098 (as defined by the NFC Forum technical specification 2099 NFCForum-TS-DigitalProtocol-1.0) via the following NFC standards: 2100 <ul> 2101 <li>NfcA (ISO14443-3A)</li> 2102 <li>NfcB (ISO14443-3B) </li> 2103 <li>NfcF (JIS 6319-4)</li> 2104 <li>IsoDep (ISO 14443-4)</li> 2105 <li>NFC Forum Tag Types 1, 2, 3, 4 (defined by the NFC Forum)</li> 2106 </ul> 2107 </li> 2108 </ul> 2109 </li> 2110 <li>SHOULD be capable of reading and writing NDEF messages via the following 2111 NFC standards. Note that while the NFC standards below are stated as 2112 "SHOULD" for Android 4.3, the Compatibility Definition for a future 2113 version is planned to change these to "MUST". That is, these standards are 2114 optional in Android 4.3 but <b>will be required</b> in future versions. 2115 Existing and new devices that run Android 4.3 are <b>very strongly 2116 encouraged to meet these requirements in Android 4.3</b> so they will be 2117 able to upgrade to the future platform releases. 2118 <ul> 2119 <li>NfcV (ISO 15693)</li> 2120 </ul> 2121 </li> 2122 <li>MUST be capable of transmitting and receiving data via the following 2123 peer-to-peer standards and protocols: 2124 <ul> 2125 <li>ISO 18092</li> 2126 <li>LLCP 1.0 (defined by the NFC Forum)</li> 2127 <li>SDP 1.0 (defined by the NFC Forum)</li> 2128 <li>NDEF Push Protocol [<a href="#resources43">Resources, 43</a>]</li> 2129 <li>SNEP 1.0 (defined by the NFC Forum)</li> 2130 </ul> 2131 </li> 2132 <li>MUST include support for Android Beam [<a href="#resources65">Resources, 65</a>]: 2133 <ul> 2134 <li>MUST implement the SNEP default server. Valid NDEF messages received 2135 by the default SNEP server MUST be dispatched to applications using 2136 the android.nfc.ACTION_NDEF_DISCOVERED intent. Disabling Android Beam 2137 in settings MUST NOT disable dispatch of incoming NDEF message.</li> 2138 <li>Device implementations MUST honor the android.settings.NFCSHARING_SETTINGS intent 2139 to show NFC sharing settings [<a href="#resources67">Resources, 67</a>].</li> 2140 <li>MUST implement the NPP server. Messages received by the NPP server MUST 2141 be processed the same way as the SNEP default server.</li> 2142 <li>MUST implement a SNEP client and attempt to send outbound P2P NDEF to 2143 the default SNEP server when Android Beam is enabled. If no default 2144 SNEP server is found then the client MUST attempt to send to an NPP 2145 server.</li> 2146 <li>MUST allow foreground activities to set the outbound P2P NDEF message 2147 using android.nfc.NfcAdapter.setNdefPushMessage, and 2148 android.nfc.NfcAdapter.setNdefPushMessageCallback, and 2149 android.nfc.NfcAdapter.enableForegroundNdefPush.</li> 2150 <li>SHOULD use a gesture or on-screen confirmation, such as 'Touch to Beam', 2151 before sending outbound P2P NDEF messages.</li> 2152 <li>SHOULD enable Android Beam by default</li> 2153 <li>MUST support NFC Connection handover to Bluetooth when the device supports Bluetooth Object Push Profile. 2154 Device implementations must support connection handover to Bluetooth when using android.nfc.NfcAdapter.setBeamPushUris, 2155 by implementing the "Connection Handover version 1.2" [<a href="#resources60">Resources, 60</a>] 2156 and "Bluetooth Secure Simple Pairing Using NFC version 1.0" [<a href="#resources61">Resources, 61</a>] 2157 specs from the NFC Forum. Such an implementation SHOULD use SNEP GET 2158 requests for exchanging the handover request / select records over NFC, and it MUST 2159 use the Bluetooth Object Push Profile for the actual Bluetooth data transfer.</li> 2160 </ul> 2161 </li> 2162 <li>MUST poll for all supported technologies while in NFC discovery mode.</li> 2163 <li>SHOULD be in NFC discovery mode while the device is awake with the screen active 2164 and the lock-screen unlocked.</li> 2165 </ul> 2166 2167 <p>(Note that publicly available links are not available for the JIS, ISO, and 2168 NFC Forum specifications cited above.)</p> 2169 <p>Additionally, device implementations MAY include reader/writer support for 2170 the following MIFARE technologies.</p> 2171 <ul> 2172 <li>MIFARE Classic (NXP MF1S503x [<a href="#resources44">Resources, 44</a>], 2173 MF1S703x [<a href="#resources45">Resources, 45</a>])</li> 2174 <li>MIFARE Ultralight (NXP MF0ICU1 [<a href="#resources46">Resources, 46</a>], 2175 MF0ICU2 [<a href="#resources47">Resources, 47</a>])</li> 2176 <li>NDEF on MIFARE Classic (NXP AN130511 [<a href="#resources48">Resources, 48</a>], 2177 AN130411 [<a href="#resources49">Resources, 49</a>])</li> 2178 </ul> 2179 <p>Note that Android 4.3 includes APIs for these MIFARE types. If a 2180 device implementation supports MIFARE in the reader/writer role, it:</p> 2181 <ul> 2182 <li>MUST implement the corresponding Android APIs as documented by the 2183 Android SDK</li> 2184 <li>MUST report the feature com.nxp.mifare from the 2185 <code>android.content.pm.PackageManager.hasSystemFeature()</code> method. 2186 [<a href="#resources37">Resources, 37</a>] Note that this is not a standard 2187 Android feature, and as such does not appear as a constant on the 2188 <code>PackageManager</code> class.</li> 2189 <li>MUST NOT implement the corresponding Android APIs nor report the 2190 com.nxp.mifare feature unless it also implements general NFC support as 2191 described in this section</li> 2192 </ul> 2193 <p>If a device implementation does not include NFC hardware, it MUST NOT 2194 declare the android.hardware.nfc feature from the 2195 <code>android.content.pm.PackageManager.hasSystemFeature()</code> method [<a 2196 href="#resources37">Resources, 37</a>], and MUST implement the Android 4.3 NFC 2197 API as a no-op.</p> 2198 <p>As the classes <code>android.nfc.NdefMessage</code> and 2199 <code>android.nfc.NdefRecord</code> represent a protocol-independent data 2200 representation format, device implementations MUST implement these APIs even 2201 if they do not include support for NFC or declare the android.hardware.nfc 2202 feature.</p> 2203 <a name="section-7.4.5"></a><h4>7.4.5. Minimum Network Capability</h4> 2204 <p>Device implementations MUST include support for one or more forms of data 2205 networking. Specifically, device implementations MUST include support for at 2206 least one data standard capable of 200Kbit/sec or greater. Examples of 2207 technologies that satisfy this requirement include EDGE, HSPA, EV-DO, 802.11g, 2208 Ethernet, etc.</p> 2209 <p>Device implementations where a physical networking standard (such as 2210 Ethernet) is the primary data connection SHOULD also include support for at 2211 least one common wireless data standard, such as 802.11 (WiFi).</p> 2212 <p>Devices MAY implement more than one form of data connectivity.</p> 2213 2214 2215 <a name="section-7.5"></a><h3>7.5. Cameras</h3> 2216 <p>Device implementations SHOULD include a rear-facing camera, and MAY include 2217 a front-facing camera. A rear-facing camera is a camera located on the side of 2218 the device opposite the display; that is, it images scenes on the far side of 2219 the device, like a traditional camera. A front-facing camera is a camera 2220 located on the same side of the device as the display; that is, a camera 2221 typically used to image the user, such as for video conferencing and similar 2222 applications.</p> 2223 <a name="section-7.5.1"></a><h4>7.5.1. Rear-Facing Camera</h4> 2224 <p>Device implementations SHOULD include a rear-facing camera. If a device 2225 implementation includes a rear-facing camera, it:</p> 2226 <ul> 2227 <li>MUST have a resolution of at least 2 megapixels</li> 2228 <li>SHOULD have either hardware auto-focus, or software auto-focus implemented 2229 in the camera driver (transparent to application software)</li> 2230 <li>MAY have fixed-focus or EDOF (extended depth of field) hardware</li> 2231 <li>MAY include a flash. If the Camera includes a flash, the flash lamp MUST 2232 NOT be lit while an android.hardware.Camera.PreviewCallback instance has been 2233 registered on a Camera preview surface, unless the application has explicitly 2234 enabled the flash by enabling the <code>FLASH_MODE_AUTO</code> or 2235 <code>FLASH_MODE_ON</code> attributes of a <code>Camera.Parameters</code> 2236 object. Note that this constraint does not apply to the device's built-in 2237 system camera application, but only to third-party applications using 2238 <code>Camera.PreviewCallback</code>.</li> 2239 </ul> 2240 <a name="section-7.5.2"></a><h4>7.5.2. Front-Facing Camera</h4> 2241 <p>Device implementations MAY include a front-facing camera. If a device 2242 implementation includes a front-facing camera, it:</p> 2243 <ul> 2244 <li>MUST have a resolution of at least VGA (that is, 640x480 pixels)</li> 2245 <li>MUST NOT use a front-facing camera as the default for the Camera API. 2246 That is, the camera API in Android 4.3 has specific support for front-facing 2247 cameras, and device implementations MUST NOT configure the API to to treat a 2248 front-facing camera as the default rear-facing camera, even if it is the only 2249 camera on the device.</li> 2250 <li>MAY include features (such as auto-focus, flash, etc.) 2251 available to rear-facing cameras as described in Section 7.5.1.</li> 2252 <li>MUST horizontally reflect (i.e. mirror) the stream displayed by an app in a 2253 CameraPreview, as follows:</li> 2254 <ul> 2255 <li>If the device implementation is capable of being rotated by user (such as 2256 automatically via an accelerometer or manually via user input), the camera 2257 preview MUST be mirrored horizontally relative to the device's current 2258 orientation.</li> 2259 <li>If the current application has explicitly requested that the Camera 2260 display be rotated via a call to the 2261 <code>android.hardware.Camera.setDisplayOrientation()</code> [<a 2262 href="#resources50">Resources, 50</a>] method, the camera preview MUST be 2263 mirrored horizontally relative to the orientation specified by the 2264 application.</li> 2265 <li>Otherwise, the preview MUST be mirrored along the device's default horizontal axis.</li> 2266 </ul> 2267 <li>MUST mirror the image displayed by the postview in the same manner as 2268 the camera preview image stream. (If the device implementation does not 2269 support postview, this requirement obviously does not apply.)</li> 2270 <li>MUST NOT mirror the final captured still image or video streams returned 2271 to application callbacks or committed to media storage</li> 2272 </ul> 2273 <a name="section-7.5.3"></a><h4>7.5.3. Camera API Behavior</h4> 2274 <p>Device implementations MUST implement the following behaviors for the 2275 camera-related APIs, for both front- and rear-facing cameras:</p> 2276 <ol> 2277 <li>If an application has never called 2278 <code>android.hardware.Camera.Parameters.setPreviewFormat(int)</code>, then the 2279 device MUST use <code>android.hardware.PixelFormat.YCbCr_420_SP</code> for 2280 preview data provided to application callbacks.</li> 2281 <li>If an application registers an <code>android.hardware.Camera.PreviewCallback 2282 </code> instance and the system calls the <code>onPreviewFrame()</code> method 2283 when the preview format is YCbCr_420_SP, the data in the <code>byte[]</code> 2284 passed into <code>onPreviewFrame()</code> must further be in the NV21 encoding 2285 format. That is, NV21 MUST be the default.</li> 2286 <li>Device implementations MUST support the YV12 format (as denoted by the 2287 <code>android.graphics.ImageFormat.YV12</code> constant) for camera previews 2288 for both front- and rear-facing cameras. (The hardware video encoder and camera 2289 may use any native pixel format, but the device implementation MUST support conversion 2290 to YV12.)</li> 2291 </ol> 2292 <p>Device implementations MUST implement the full Camera API included in the 2293 Android 4.3 SDK documentation [<a href="#resources51">Resources, 51</a>]), 2294 regardless of whether the device includes hardware autofocus or other 2295 capabilities. For instance, cameras that lack autofocus MUST still call any 2296 registered <code>android.hardware.Camera.AutoFocusCallback</code> instances (even though 2297 this has no relevance to a non-autofocus camera.) Note that this does apply 2298 to front-facing cameras; for instance, even though most front-facing cameras 2299 do not support autofocus, the API callbacks must still be "faked" as 2300 described.</p> 2301 <p>Device implementations MUST recognize and honor each parameter name defined 2302 as a constant on the <code>android.hardware.Camera.Parameters</code> class, if the 2303 underlying hardware supports the feature. If the device hardware does not 2304 support a feature, the API must behave as documented. Conversely, Device 2305 implementations MUST NOT honor or recognize string constants passed 2306 to the <code>android.hardware.Camera.setParameters()</code> method other than 2307 those documented as constants on the 2308 <code>android.hardware.Camera.Parameters</code>. That is, 2309 device implementations MUST support all standard Camera parameters if the 2310 hardware allows, and MUST NOT support custom Camera parameter types. 2311 For instance, device implementations that support image capture using high dynamic range (HDR) 2312 imaging techniques MUST support camera parameter <code>Camera.SCENE_MODE_HDR</code> 2313 [<a href="#resources78">Resources, 78</a>]).</p> 2314 <p>Device implementations MUST broadcast the <code>Camera.ACTION_NEW_PICTURE</code> 2315 intent whenever a new picture is taken by the camera and the entry of the picture 2316 has been added to the media store.</p> 2317 <p>Device implementations MUST broadcast the <code>Camera.ACTION_NEW_VIDEO</code> 2318 intent whenever a new video is recorded by the camera and the entry of the picture 2319 has been added to the media store.</p> 2320 <a name="section-7.5.4"></a><h4>7.5.4. Camera Orientation</h4> 2321 <p>Both front- and rear-facing cameras, if present, MUST be oriented so that 2322 the long dimension of the camera aligns with the screen's long dimension. That 2323 is, when the device is held in the landscape orientation, cameras MUST 2324 capture images in the landscape orientation. This applies regardless of the 2325 device's natural orientation; that is, it applies to landscape-primary devices 2326 as well as portrait-primary devices.</p> 2327 2328 <a name="section-7.6"></a><h3>7.6. Memory and Storage</h3> 2329 <a name="section-7.6.1"></a><h4>7.6.1. Minimum Memory and Storage</h4> 2330 <p>Device implementations MUST have at least 340MB of memory available to the 2331 kernel and userspace. The 340MB MUST be in addition to any memory dedicated to 2332 hardware components such as radio, video, and so on that is not under the 2333 kernel's control.</p> 2334 <p>Device implementations MUST have at least 512MB of non-volatile storage available 2335 for application private data. That is, the <code>/data</code> partition MUST be at 2336 least 512MB. Device implementations that run Android 4.3 are <b>very strongly encouraged to 2337 have at least 1GB of non-volatile storage for application private data</b> so they will be 2338 able to upgrade to the future platform releases.</p> 2339 2340 <p>The Android APIs include a Download Manager that applications may use to 2341 download data files [<a href="#resources56">Resources, 56</a>]. The device 2342 implementation of the Download Manager MUST be capable of downloading individual 2343 files of at least 100MB in size to the default "cache" location.</p> 2344 <a name="section-7.6.2"></a><h4>7.6.2. Application Shared Storage</h4> 2345 <p>Device implementations MUST offer shared storage for applications. The 2346 shared storage provided MUST be at least 1GB in size.</p> 2347 <p>Device implementations MUST be configured with shared storage mounted by 2348 default, "out of the box". If the shared storage is not mounted on the Linux 2349 path <code>/sdcard</code>, then the device MUST include a Linux symbolic link 2350 from <code>/sdcard</code> to the actual mount point.</p> 2351 <p>Device implementations MUST enforce as documented the 2352 <code>android.permission.WRITE_EXTERNAL_STORAGE</code> permission on this 2353 shared storage. Shared storage MUST otherwise be writable by any application 2354 that obtains that permission.</p> 2355 <p>Device implementations MAY have hardware for user-accessible removable 2356 storage, such as a Secure Digital card. Alternatively, device implementations 2357 MAY allocate internal (non-removable) storage as shared storage for apps.</p> 2358 <p>Regardless of the form of shared storage used, device implementations MUST 2359 provide some mechanism to access the contents of shared storage from a host 2360 computer, such as USB mass storage (UMS) or Media Transfer Protocol (MTP). Device 2361 implementations MAY use USB mass storage, but SHOULD use Media Transfer 2362 Protocol. If the device implementation supports Media Transfer Protocol:</p> 2363 <ul> 2364 <li>The device implementation SHOULD be compatible with the reference Android 2365 MTP host, Android File Transfer [<a href="#resources57">Resources, 57</a>].</li> 2366 <li>The device implementation SHOULD report a USB device class of <code>0x00</code>.</li> 2367 <li>The device implementation SHOULD report a USB interface name of 'MTP'.</li> 2368 </ul> 2369 <p>If the device implementation lacks USB ports, it MUST provide a host 2370 computer with access to the contents of shared storage by some other means, 2371 such as a network file system.</p> 2372 <p>It is illustrative to consider two common examples. If a device 2373 implementation includes an SD card slot to satisfy the shared storage 2374 requirement, a FAT-formatted SD card 1GB in size or larger MUST be included 2375 with the device as sold to users, and MUST be mounted by default. 2376 Alternatively, if a device implementation uses internal fixed storage to 2377 satisfy this requirement, that storage MUST be 1GB in size or larger 2378 and mounted on <code>/sdcard</code> (or <code>/sdcard</code> 2379 MUST be a symbolic link to the physical location if it is mounted elsewhere.)</p> 2380 <p>Device implementations that include multiple shared storage paths (such as 2381 both an SD card slot and shared internal storage) SHOULD modify the core 2382 applications such as the media scanner and ContentProvider to transparently 2383 support files placed in both locations.</p> 2384 2385 <a name="section-7.7"></a><h3>7.7. USB</h3> 2386 <p>Device implementations SHOULD include a USB client port, and SHOULD include 2387 a USB host port.</p> 2388 <p>If a device implementation includes a USB client port:</p> 2389 <ul> 2390 <li>the port MUST be connectable to a USB host with a standard USB-A port</li> 2391 <li>the port SHOULD use the micro USB form factor on the device side. Existing and 2392 new devices that run Android 4.3 are <b>very strongly encouraged to meet these requirements 2393 in Android 4.3</b> so they will be able to upgrade to the future platform releases</li> 2394 <li>the port SHOULD be centered in the middle of an edge. Device implementations SHOULD either 2395 locate the port on the bottom of the device (according to natural orientation) or enable software 2396 screen rotation for all apps (including home screen), so that the display draws correctly when the device 2397 is oriented with the port at bottom. Existing and new devices that run Android 4.3 are <b>very strongly 2398 encouraged to meet these requirements in Android 4.3</b> so they will be able to upgrade to future platform releases.</li> 2399 <li>if the device has other ports (such as a non-USB charging port) it SHOULD be on the same edge as the 2400 micro-USB port</li> 2401 <li>it MUST allow a host connected to the device to access the contents of the 2402 shared storage volume using either USB mass storage or Media Transfer 2403 Protocol</li> 2404 <li>it MUST implement the Android Open Accessory API and specification as documented 2405 in the Android SDK documentation, and MUST declare support for the hardware 2406 feature <code>android.hardware.usb.accessory</code> [<a href="#resources52">Resources, 2407 52</a>]</li> 2408 <li>it MUST implement the USB audio class as documented in the Android SDK documentation [<a href="#resources66">Resources, 66</a>]</li> 2409 <li>it SHOULD implement support for USB battery charging specification [<a href="#resources64">Resources, 64</a>] 2410 Existing and new devices that run Android 4.3 are <b>very strongly encouraged to meet these requirements in Android 4.3</b> 2411 so they will be able to upgrade to the future platform releases</li> 2412 2413 </ul> 2414 <p>If a device implementation includes a USB host port:</p> 2415 <ul> 2416 <li>it MAY use a non-standard port form factor, but if so MUST ship with a 2417 cable or cables adapting the port to standard USB-A</li> 2418 <li>it MUST implement the Android USB host API as documented in the Android 2419 SDK, and MUST declare support for the hardware feature 2420 <code>android.hardware.usb.host</code> [<a href="#resources53">Resources, 53</a>]</li> 2421 </ul> 2422 <p>Device implementations MUST implement the Android Debug Bridge. If a device 2423 implementation omits a USB client port, it MUST implement the Android Debug 2424 Bridge via local-area network (such as Ethernet or 802.11)</p> 2425 2426 <a name="section-8"></a><h2>8. Performance Compatibility</h2> 2427 <p>Device implementations MUST meet the key performance metrics of an Android 2428 4.3 compatible device defined in the table below:</p> 2429 <table><tbody><tr> 2430 <td><b>Metric</b></td> 2431 <td><b>Performance Threshold</b></td> 2432 <td><b>Comments</b></td> 2433 </tr> 2434 <tr> 2435 <td>Application Launch Time</td> 2436 <td>The following applications should launch within the specified time.<ul> 2437 <li>Browser: less than 1300ms</li> 2438 <li>Contacts: less than 700ms</li> 2439 <li>Settings: less than 700ms</li> 2440 </ul></td> 2441 <td>The launch time is measured as the total time to 2442 complete loading the default activity for the application, including the time 2443 it takes to start the Linux process, load the Android package into the Dalvik 2444 VM, and call onCreate.</td> 2445 </tr> 2446 <tr> 2447 <td>Simultaneous Applications</td> 2448 <td>When multiple applications have been launched, re-launching an 2449 already-running application after it has been launched must take less than the 2450 original launch time.</td> 2451 <td> </td> 2452 </tr> 2453 </tbody> 2454 </table> 2455 2456 <a name="section-9"></a><h2>9. Security Model Compatibility</h2> 2457 <p>Device implementations MUST implement a security model consistent with the 2458 Android platform security model as defined in Security and Permissions 2459 reference document in the APIs [<a href="#resources54">Resources, 54</a>] in the 2460 Android developer documentation. Device implementations MUST support 2461 installation of self-signed applications without requiring any additional 2462 permissions/certificates from any third parties/authorities. Specifically, 2463 compatible devices MUST support the security mechanisms described in the 2464 follow sub-sections.</p> 2465 <a name="section-9.1"></a><h3>9.1. Permissions</h3> 2466 <p>Device implementations MUST support the Android permissions model as 2467 defined in the Android developer documentation [<a 2468 href="#resources54">Resources, 54</a>]. Specifically, 2469 implementations MUST enforce each permission defined as described in the SDK 2470 documentation; no permissions may be omitted, altered, or ignored. 2471 Implementations MAY add additional permissions, provided the new permission ID 2472 strings are not in the android.* namespace.</p> 2473 <a name="section-9.2"></a><h3>9.2. UID and Process Isolation</h3> 2474 <p>Device implementations MUST support the Android application sandbox model, 2475 in which each application runs as a unique Unix-style UID and in a separate 2476 process. Device implementations MUST support running multiple applications as 2477 the same Linux user ID, provided that the applications are properly signed and 2478 constructed, as defined in the Security and Permissions reference [<a 2479 href="#resources54">Resources, 54</a>].</p> 2480 <a name="section-9.3"></a><h3>9.3. Filesystem Permissions</h3> 2481 <p>Device implementations MUST support the Android file access permissions 2482 model as defined in the Security and Permissions reference [<a 2483 href="#resources54">Resources, 54</a>].</p> 2484 <a name="section-9.4"></a><h3>9.4. Alternate Execution Environments</h3> 2485 <p>Device implementations MAY include runtime environments that execute 2486 applications using some other software or technology than the Dalvik virtual 2487 machine or native code. However, such alternate execution environments MUST 2488 NOT compromise the Android security model or the security of installed Android 2489 applications, as described in this section.</p> 2490 <p>Alternate runtimes MUST themselves be Android applications, and abide by 2491 the standard Android security model, as described elsewhere in Section 9.</p> 2492 <p>Alternate runtimes MUST NOT be granted access to resources protected by 2493 permissions not requested in the runtime's AndroidManifest.xml file via the 2494 <code><uses-permission></code> mechanism.</p> 2495 <p>Alternate runtimes MUST NOT permit applications to make use of features 2496 protected by Android permissions restricted to system applications.</p> 2497 <p>Alternate runtimes MUST abide by the Android sandbox model. Specifically:</p> 2498 <ul> 2499 <li>Alternate runtimes SHOULD install apps via the PackageManager into 2500 separate Android sandboxes (that is, Linux user IDs, etc.)</li> 2501 <li>Alternate runtimes MAY provide a single Android sandbox shared by all 2502 applications using the alternate runtime</li> 2503 <li>Alternate runtimes and installed applications using an alternate runtime 2504 MUST NOT reuse the sandbox of any other app installed on the device, except 2505 through the standard Android mechanisms of shared user ID and signing 2506 certificate</li> 2507 <li>Alternate runtimes MUST NOT launch with, grant, or be granted access to 2508 the sandboxes corresponding to other Android applications</li> 2509 </ul> 2510 <p>Alternate runtimes MUST NOT be launched with, be granted, or grant to other 2511 applications any privileges of the superuser (root), or of any other user ID.</p> 2512 <p>The .apk files of alternate runtimes MAY be included in the system image of 2513 a device implementation, but MUST be signed with a key distinct 2514 from the key used to sign other applications included with the device 2515 implementation.</p> 2516 <p>When installing applications, alternate runtimes MUST obtain user consent 2517 for the Android permissions used by the application. That is, if an 2518 application needs to make use of a device resource for which there is a 2519 corresponding Android permission (such as Camera, GPS, etc.), the alternate 2520 runtime MUST inform the user that the application will be able to access 2521 that resource. If the runtime environment does not record application 2522 capabilities in this manner, the runtime environment MUST list all 2523 permissions held by the runtime itself when installing any application 2524 using that runtime.</p> 2525 2526 <a name="section-9.5"></a><h3>9.5. Multi-User Support </h3> 2527 <p>Android 4.3 includes support for multiple users and provides support for full user isolation 2528 [<a href="#resources70">Resources, 70</a>].</p> 2529 <p>Device implementations MUST meet these requirements related to multi-user support [<a href="#resources71">Resources, 71</a>]:</p> 2530 <ul> 2531 <li>As the behavior of the telephony APIs on devices with multiple users is currently undefined, device implementations that 2532 declare android.hardware.telephony MUST NOT enable multi-user support. </li> 2533 <li>Device implementations MUST, for each user, implement a security model consistent with the Android platform security model 2534 as defined in Security and Permissions reference document in the APIs [Resources, 54]</li> 2535 <li>Android 4.3 includes support for restricted profiles, a feature that allows device owners to manage additional users and their capabilities 2536 on the device. With restricted profiles, device owners can quickly set up separate environments for additional users to work in, with the ability to 2537 manage finer-grained restrictions in the apps that are available in those environments. Device implementations that include support for multiple users 2538 MUST include support for restricted profiles. The upstream Android Open Source Project includes an implementation that satisfies this requirement.</li> 2539 </ul> 2540 2541 <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. 2542 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. 2543 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 2544 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 2545 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 2546 implementations MAY but SHOULD NOT enable multi-user if they use removable media [<a href="#resources72">Resources, 72</a>] for primary external storage. The upstream Android Open Source 2547 Project includes an implementation that uses internal device storage for application external storage APIs; device implementations SHOULD use this configuration and software implementation. 2548 Device implementations that include multiple external storage paths MUST NOT allow Android applications to write to the secondary external storage.</p> 2549 2550 <a name="section-9.6"></a><h3>9.6. Premium SMS Warning</h3> 2551 <p>Android 4.3 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. 2552 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. 2553 The upstream Android Open Source Project provides an implementation that satisfies this requirement. 2554 </p> 2555 2556 <a name="section-9.7"></a><h3>9.7. Kernel Security Features</h3> 2557 <p>The Android Sandbox in Android 4.3 includes features that can use the SELinux 2558 mandatory access control system (MAC) and other security features in the Linux kernel. 2559 Device implementations MUST support SELinux MAC. Note that the upstream Android Open Source 2560 Project provides an implementation that satisfies this requirement.</p> 2561 2562 <p>SELinux or any security features implemented below the Android framework MUST maintain 2563 compatibility with existing applications. These features SHOULD be invisible to users and developers. 2564 These features SHOULD NOT be user or developer configurable. If any API for configuration of policy is 2565 exposed to an application that can affect another application (such as a Device Administration API), 2566 the API MUST NOT allow configurations that break compatibility. To ensure continued compatibility the 2567 reference implementation allows the use of SELinux in a permissive mode and supports dynamic policy updates 2568 without requiring a system image update. Device implementations using SELinux MUST support this permissive 2569 mode, support dynamic policy updates and log any policy violations without breaking applications or affecting 2570 system behavior. Implementations using SELinux SHOULD load policy from <code>/sepolicy</code> file on the device. 2571 The upstream Android Open Source Project provides an implementation that satisfies this requirement. 2572 Device implementations SHOULD use the reference implementation in the Android Open Source Project, and 2573 device implementations MUST be compatible with the upstream Android Open Source Project.</p> 2574 2575 <a name="section-10"></a><h2>10. Software Compatibility Testing</h2> 2576 <p>Device implementations MUST pass all tests described in this section.</p> 2577 <p>However, note that no software test package is fully comprehensive. For 2578 this reason, device implementers are very strongly encouraged to make the 2579 minimum number of changes as possible to the reference and preferred 2580 implementation of Android 4.3 available from the Android Open Source Project. 2581 This will minimize the risk of introducing bugs that create incompatibilities 2582 requiring rework and potential device updates.</p> 2583 <a name="section-10.1"></a><h3>10.1. Compatibility Test Suite</h3> 2584 <p>Device implementations MUST pass the Android Compatibility Test Suite (CTS) 2585 [<a href="#resources02">Resources, 2</a>] available from the Android Open Source 2586 Project, using the final shipping software on the device. Additionally, device 2587 implementers SHOULD use the reference implementation in the Android Open 2588 Source tree as much as possible, and MUST ensure compatibility in cases of 2589 ambiguity in CTS and for any reimplementations of parts of the reference 2590 source code.</p> 2591 <p>The CTS is designed to be run on an actual device. Like any software, the 2592 CTS may itself contain bugs. The CTS will be versioned independently of this 2593 Compatibility Definition, and multiple revisions of the CTS may be released 2594 for Android 4.3. Device implementations MUST pass the latest CTS version 2595 available at the time the device software is completed.</p> 2596 <a name="section-10.2"></a><h3>10.2. CTS Verifier</h3> 2597 <p>Device implementations MUST correctly execute all applicable cases in the 2598 CTS Verifier. The CTS Verifier is included with the Compatibility Test Suite, 2599 and is intended to be run by a human operator to test functionality that 2600 cannot be tested by an automated system, such as correct functioning of a 2601 camera and sensors.</p> 2602 <p>The CTS Verifier has tests for many kinds of hardware, including some 2603 hardware that is optional. Device implementations MUST pass all tests for 2604 hardware which they possess; for instance, if a device possesses an 2605 accelerometer, it MUST correctly execute the Accelerometer test case in the 2606 CTS Verifier. Test cases for features noted as optional by this Compatibility 2607 Definition Document MAY be skipped or omitted.</p> 2608 <p>Every device and every build MUST correctly run the CTS Verifier, as noted 2609 above. However, since many builds are very similar, device implementers are 2610 not expected to explicitly run the CTS Verifier on builds that differ only in 2611 trivial ways. Specifically, device implementations that differ from an 2612 implementation that has passed the CTS Verifier only by the set of included 2613 locales, branding, etc. MAY omit the CTS Verifier test.</p> 2614 <a name="section-10.3"></a><h3>10.3. Reference Applications</h3> 2615 <p>Device implementers MUST test implementation compatibility using the 2616 following open source applications:</p> 2617 <ul> 2618 <li>The "Apps for Android" applications [<a href="#resources55">Resources, 55</a>]</li> 2619 <li>Replica Island (available in Google Play Store)</li> 2620 </ul> 2621 <p>Each app above MUST launch and behave correctly on the implementation, for 2622 the implementation to be considered compatible.</p> 2623 2624 2625 <a name="section-11"></a><h2>11. Updatable Software</h2> 2626 <p>Device implementations MUST include a mechanism to replace the entirety of 2627 the system software. The mechanism need not perform "live" upgrades - that 2628 is, a device restart MAY be required.</p> 2629 <p>Any method can be used, provided that it can replace the entirety of the 2630 software preinstalled on the device. For instance, any of the following 2631 approaches will satisfy this requirement:</p> 2632 <ul> 2633 <li>Over-the-air (OTA) downloads with offline update via reboot</li> 2634 <li>"Tethered" updates over USB from a host PC</li> 2635 <li>"Offline" updates via a reboot and update from a file on removable 2636 storage</li> 2637 </ul> 2638 <p>The update mechanism used MUST support updates without wiping user data. 2639 That is, the update mechanism MUST preserve application private data 2640 and application shared data. Note that the upstream Android software includes 2641 an update mechanism that satisfies this requirement.</p> 2642 <p>If an error is found in a device implementation after it has been released 2643 but within its reasonable product lifetime that is determined in consultation 2644 with the Android Compatibility Team to affect the compatibility of third-party 2645 applications, the device implementer MUST correct the error via a software 2646 update available that can be applied per the mechanism just described.</p> 2647 2648 <a name="section-12"></a><h2>12. Contact Us</h2> 2649 <p>You can contact the document authors at <a 2650 href="mailto:compatibility (a] android.com">compatibility (a] android.com</a> for 2651 clarifications and to bring up any issues that you think the document does not 2652 cover.</p> 2653 2654 <div style="page-break-before: always;"></div> 2655 2656 <div id="footerContent" xmlns:pdf="http://whatever"> 2657 <pdf:pagenumber/> 2658 </div> 2659 </body> 2660 </html> 2661
