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 4.2Compatibility Definition</title> 6 <link rel="stylesheet" type="text/css" href="cdd.css"/> 7 </head> 8 <body> 9 <div><img src="header.jpg" alt="Android logo"/></div> 10 <h1>Android 4.2 Compatibility Definition</h1> 11 <!-- 12 <span style="color: red; font-weight: bold;"><h2>Revision 1</h2></span><br/> 13 <span style="color: red;">Last updated: October 17, 2012</span> 14 --> 15 <p><b><font color="red">Revision 2</font></b><br/> 16 Last updated: Feb 17, 2013 17 </p> 18 <p>Copyright © 2012, Google Inc. All rights reserved.<br/> 19 <a href="mailto:compatibility (a] android.com">compatibility (a] android.com</a> 20 </p> 21 22 <h2> Table of Contents</h2> 23 <div style="margin-left: 2em;"> 24 <a href="#section-1">1. Introduction</a><br/> 25 <a href="#section-2">2. Resources</a><br/> 26 <a href="#section-3">3. Software</a><br/> 27 <div style="margin-left: 2em;"> 28 <a href="#section-3.1">3.1. Managed API Compatibility</a><br/> 29 <a href="#section-3.2">3.2. Soft API Compatibility</a><br/> 30 <div style="margin-left: 2em;"> 31 <a href="#section-3.2.1">3.2.1. Permissions</a><br/> 32 <a href="#section-3.2.2">3.2.2. Build Parameters</a><br/> 33 <a href="#section-3.2.3">3.2.3. Intent Compatibility</a><br/> 34 <div style="margin-left: 2em;"> 35 <a href="#section-3.2.3.1">3.2.3.1. Core Application Intents</a><br/> 36 <a href="#section-3.2.3.2">3.2.3.2. Intent Overrides</a><br/> 37 <a href="#section-3.2.3.3">3.2.3.3. Intent Namespaces</a><br/> 38 <a href="#section-3.2.3.4">3.2.3.4. Broadcast Intents</a><br/> 39 </div> 40 </div> 41 <a href="#section-3.3">3.3. Native API Compatibility</a><br/> 42 <div style="margin-left: 2em;"> 43 <a href="#section-3.3.1">3.3.1 Application Binary Interfaces</a><br/> 44 </div> 45 <a href="#section-3.4">3.4. Web Compatibility</a><br/> 46 <div style="margin-left: 2em;"> 47 <a href="#section-3.4.1">3.4.1. WebView Compatibility</a><br/> 48 <a href="#section-3.4.2">3.4.2. Browser Compatibility</a><br/> 49 </div> 50 <a href="#section-3.5">3.5. API Behavioral Compatibility</a><br/> 51 <a href="#section-3.6">3.6. API Namespaces</a><br/> 52 <a href="#section-3.7">3.7. Virtual Machine Compatibility</a><br/> 53 <a href="#section-3.8">3.8. User Interface Compatibility</a><br/> 54 <div style="margin-left: 2em;"> 55 <a href="#section-3.8.1">3.8.1. Widgets</a><br/> 56 <a href="#section-3.8.2">3.8.2. Notifications</a><br/> 57 <a href="#section-3.8.3">3.8.3. Search</a><br/> 58 <a href="#section-3.8.4">3.8.4. Toasts</a><br/> 59 <a href="#section-3.8.5">3.8.5. Themes</a><br/> 60 <a href="#section-3.8.6">3.8.6. Live Wallpapers</a><br/> 61 <a href="#section-3.8.7">3.8.7. Recent Application Display</a><br/> 62 <a href="#section-3.8.8">3.8.8. Input Management Settings</a><br/> 63 <a href="#section-3.8.9">3.8.9. Lock and Home Screen Widgets</a><br/> 64 <a href="#section-3.8.10">3.8.10. Lock Screen Media Remote Control</a><br/> 65 <a href="#section-3.8.11">3.8.11. Dreams</a><br/> 66 </div> 67 <a href="#section-3.9">3.9 Device Administration</a><br/> 68 <a href="#section-3.10">3.10 Accessibility</a><br/> 69 <a href="#section-3.11">3.11 Text-to-Speech</a><br/> 70 </div> 71 <a href="#section-4">4. Application Packaging Compatibility</a><br/> 72 <a href="#section-5">5. Multimedia Compatibility</a><br/> 73 <div style="margin-left: 2em;"> 74 <a href="#section-5.1">5.1. Media Codecs</a><br/> 75 <a href="#section-5.2">5.2. Video Encoding</a><br/> 76 <a href="#section-5.3">5.3. Video Decoding</a><br/> 77 <a href="#section-5.4">5.4. Audio Recording</a><br/> 78 <a href="#section-5.5">5.5. Audio Latency</a><br/> 79 <a href="#section-5.6">5.6. Network Protocols</a><br/> 80 </div> 81 <a href="#section-6">6. Developer Tools and Options Compatibility</a><br/> 82 <div style="margin-left: 2em;"> 83 <a href="#section-6.1">6.1. Developer Tools</a><br/> 84 <a href="#section-6.2">6.2. Developer Options</a><br/> 85 </div> 86 <a href="#section-7">7. Hardware Compatibility</a><br/> 87 <div style="margin-left: 2em;"> 88 <a href="#section-7.1">7.1. Display and Graphics</a><br/> 89 <div style="margin-left: 2em;"> 90 <a href="#section-7.1.1">7.1.1. Screen Configuration</a><br/> 91 <a href="#section-7.1.2">7.1.2. Display Metrics</a><br/> 92 <a href="#section-7.1.3">7.1.3. Screen Orientation</a><br/> 93 <a href="#section-7.1.4">7.1.4. 2D and 3D Graphics Accleration</a><br/> 94 <a href="#section-7.1.5">7.1.5. Legacy Application Compatibility Mode</a><br/> 95 <a href="#section-7.1.6">7.1.6. Screen Types</a><br/> 96 <a href="#section-7.1.7">7.1.7. Screen Technology</a><br/> 97 <a href="#section-7.1.8">7.1.8. External Displays</a><br/> 98 </div> 99 <a href="#section-7.2">7.2. Input Devices</a><br/> 100 <div style="margin-left: 2em;"> 101 <a href="#section-7.2.1">7.2.1. Keyboard</a><br/> 102 <a href="#section-7.2.2">7.2.2. Non-touch Navigation</a><br/> 103 <a href="#section-7.2.3">7.2.3. Navigation keys</a><br/> 104 <a href="#section-7.2.4">7.2.4. Touchscreen input</a><br/> 105 </div> 106 <a href="#section-7.3">7.3. Sensors</a><br/> 107 <div style="margin-left: 2em;"> 108 <a href="#section-7.3.1">7.3.1. Accelerometer</a><br/> 109 <a href="#section-7.3.2">7.3.2. Magnetometer</a><br/> 110 <a href="#section-7.3.3">7.3.3. GPS</a><br/> 111 <a href="#section-7.3.4">7.3.4. Gyroscope</a><br/> 112 <a href="#section-7.3.5">7.3.5. Barometer</a><br/> 113 <a href="#section-7.3.6">7.3.6. Thermometer</a><br/> 114 <a href="#section-7.3.7">7.3.7. Photometer</a><br/> 115 <a href="#section-7.3.8">7.3.8. Proximity Sensor</a><br/> 116 </div> 117 <a href="#section-7.4">7.4. Data Connectivity</a><br/> 118 <div style="margin-left: 2em;"> 119 <a href="#section-7.4.1">7.4.1. Telephony</a><br/> 120 <a href="#section-7.4.2">7.4.2. IEEE 802.11 (WiFi)</a><br/> 121 <div style="margin-left: 2em;"> 122 <a href="#section-7.4.2.1">7.4.2.1. WiFi Direct</a><br/> 123 </div> 124 <a href="#section-7.4.3">7.4.3. Bluetooth</a><br/> 125 <a href="#section-7.4.4">7.4.4. Near-Field Communications</a><br/> 126 <a href="#section-7.4.5">7.4.5. Minimum Network Capability</a><br/> 127 </div> 128 <a href="#section-7.5">7.5. Cameras</a><br/> 129 <div style="margin-left: 2em;"> 130 <a href="#section-7.5.1">7.5.1. Rear-Facing Camera</a><br/> 131 <a href="#section-7.5.2">7.5.2. Front-Facing Camera</a><br/> 132 <a href="#section-7.5.3">7.5.3. Camera API Behavior</a><br/> 133 <a href="#section-7.5.4">7.5.4. Camera Orientation</a><br/> 134 </div> 135 <a href="#section-7.6">7.6. Memory and Storage</a><br/> 136 <div style="margin-left: 2em;"> 137 <a href="#section-7.6.1">7.6.1. Minimum Memory and Storage</a><br/> 138 <a href="#section-7.6.2">7.6.2. Application Shared Storage</a><br/> 139 </div> 140 <a href="#section-7.7">7.7. USB</a><br/> 141 </div> 142 <a href="#section-8">8. Performance Compatibility</a><br/> 143 <a href="#section-9">9. Security Model Compatibility</a><br/> 144 <div style="margin-left: 2em;"> 145 <a href="#section-9.1">9.1. Permissions</a><br/> 146 <a href="#section-9.2">9.2. UID and Process Isolation</a><br/> 147 <a href="#section-9.3">9.3. Filesystem Permissions</a><br/> 148 <a href="#section-9.4">9.4. Alternate Execution Environments</a><br/> 149 <a href="#section-9.5">9.5. Multi-User Support</a><br/> 150 <a href="#section-9.6">9.6. Premium SMS Warning</a><br/> 151 </div> 152 <a href="#section-10">10. Software Compatibility Testing</a><br/> 153 <div style="margin-left: 2em;"> 154 <a href="#section-10.1">10.1. Compatibility Test Suite</a><br/> 155 <a href="#section-10.2">10.2. CTS Verifier</a><br/> 156 <a href="#section-10.3">10.3. Reference Applications</a><br/> 157 </div> 158 <a href="#section-11">11. Updatable Software</a><br/> 159 <a href="#section-12">12. Contact Us</a><br/> 160 <a href="#appendix-A">Appendix A - Bluetooth Test Procedure</a><br/> 161 </div> 162 163 <div style="page-break-before: always;"></div> 164 165 <a name="section-1"></a><h2>1. Introduction</h2> 166 <p>This document enumerates the requirements that must be met in order for 167 devices to be compatible with Android 4.2.</p> 168 <p>The use of "must", "must not", "required", "shall", "shall not", "should", 169 "should not", "recommended", "may" and "optional" is per the IETF standard 170 defined in RFC2119 [<a href="#resources01">Resources, 1</a>].</p> 171 <p>As used in this document, a "device implementer" or "implementer" is a 172 person or organization developing a hardware/software solution running Android 173 4.2. A "device implementation" or "implementation" is the hardware/software 174 solution so developed.</p> 175 <p>To be considered compatible with Android 4.2, device implementations 176 MUST meet the requirements presented in this Compatibility Definition, 177 including any documents incorporated via reference.</p> 178 <p>Where this definition or the software tests described in <a 179 href="#section-10">Section 10</a> is silent, ambiguous, or incomplete, it is 180 the responsibility of the device implementer to ensure compatibility with 181 existing implementations.</p> 182 <p>For this reason, the Android Open Source Project [<a 183 href="#resources03">Resources, 3</a>] is both the reference and preferred 184 implementation of Android. Device implementers are strongly encouraged to base 185 their implementations to the greatest extent possible on the "upstream" source 186 code available from the Android Open Source Project. While some components can 187 hypothetically be replaced with alternate implementations this practice is 188 strongly discouraged, as passing the software tests will become substantially 189 more difficult. It is the implementer's responsibility to ensure full 190 behavioral compatibility with the standard Android implementation, including 191 and beyond the Compatibility Test Suite. Finally, note that certain component 192 substitutions and modifications are explicitly forbidden by this document.</p> 193 <a name="section-2"></a><h2>2. Resources</h2> 194 <ol> 195 <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> 196 <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> 197 <a name="resources03"></a><li>Android Open Source Project: <a href="http://source.android.com/">http://source.android.com/</a></li> 198 <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> 199 <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> 200 <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> 201 <a name="resources07"></a><li>Android 4.2 allowed version strings: <a href="http://source.android.com/compatibility/4.2/versions.html">http://source.android.com/compatibility/4.2/versions.html</a></li> 202 <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> 203 <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> 204 <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> 205 <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> 206 <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> 207 <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> 208 <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> 209 <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> 210 <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> 211 <a name="resources17"></a><li>Dalvik Virtual Machine specification: available in the Android source code, at dalvik/docs</li> 212 <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> 213 <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> 214 <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> 215 <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> 216 <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> 217 <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> 218 <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> 219 <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> 220 <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> 221 <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> 222 <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> 223 <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> 224 <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> 225 <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> 226 <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> 227 <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> 228 <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> 229 <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> 230 <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> 231 <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> 232 <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> 233 <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> 234 <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> 235 <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> 236 <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> 237 <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> 238 <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> 239 <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> 240 <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> 241 <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> 242 <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> 243 <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> 244 <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> 245 <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> 246 <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> 247 <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> 248 <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> 249 <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> 250 <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> 251 <a name="resources57"></a><li>Android File Transfer: <a href="http://www.android.com/filetransfer">http://www.android.com/filetransfer</a></li> 252 <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> 253 <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> 254 <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> 255 <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> 256 <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> 257 <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> 258 <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> 259 <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> 260 <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> 261 <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> 262 <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> 263 <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> 264 <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> 265 <a name="resources71"></a><li>External Storage reference: <a href="http://source.android.com/tech/storage">http://source.android.com/tech/storage</a></li> 266 <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> 267 <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> 268 <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> 269 <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> 270 <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> 271 <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> 272 </ol> 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 <p>Many of these resources are derived directly or indirectly from the Android 275 4.2 SDK, and will be functionally identical to the information in that SDK's 276 documentation. In any cases where this Compatibility Definition or the 277 Compatibility Test Suite disagrees with the SDK documentation, the SDK 278 documentation is considered authoritative. Any technical details provided in 279 the references included above are considered by inclusion to be part of this 280 Compatibility Definition.</p> 281 282 <a name="section-3"></a><h2>3. Software</h2> 283 <a name="section-3.1"></a><h3>3.1. Managed API Compatibility</h3> 284 <p>The managed (Dalvik-based) execution environment is the primary vehicle for 285 Android applications. The Android application programming interface (API) is 286 the set of Android platform interfaces exposed to applications running in the 287 managed VM environment. Device implementations MUST provide complete 288 implementations, including all documented behaviors, of any documented API 289 exposed by the Android 4.2 SDK [<a href="#resources04">Resources, 4</a>].</p> 290 <p>Device implementations MUST NOT omit any managed APIs, alter API interfaces 291 or signatures, deviate from the documented behavior, or include no-ops, except 292 where specifically allowed by this Compatibility Definition.</p> 293 <p>This Compatibility Definition permits some types of hardware for which 294 Android includes APIs to be omitted by device implementations. In such cases, 295 the APIs MUST still be present and behave in a reasonable way. See 296 <a href="#section-7">Section 7</a> for specific requirements for this scenario. 297 </p> 298 299 <a name="section-3.2"></a><h3>3.2. Soft API Compatibility</h3> 300 <p>In addition to the managed APIs from Section 3.1, Android also includes a 301 significant runtime-only "soft" API, in the form of such things such as 302 Intents, permissions, and similar aspects of Android applications that cannot 303 be enforced at application compile time.</p> 304 <a name="section-3.2.1"></a><h4>3.2.1. Permissions</h4> 305 <p>Device implementers MUST support and enforce all permission constants as 306 documented by the Permission reference page [<a 307 href="#resources05">Resources, 5</a>]. Note that Section 10 lists additional 308 requirements related to the Android security model.</p> 309 <a name="section-3.2.2"></a><h4>3.2.2. Build Parameters</h4> 310 <p>The Android APIs include a number of constants on the <code>android.os.Build</code> 311 class [<a href="#resources06">Resources, 6</a>] that are intended to describe 312 the current device. To provide consistent, meaningful values across device 313 implementations, the table below includes additional restrictions on the 314 formats of these values to which device implementations MUST conform.</p> 315 <table> 316 <tbody> 317 <tr> 318 <td><b>Parameter</b></td> 319 <td><b>Comments</b></td> 320 </tr> 321 <tr> 322 <td>android.os.Build.VERSION.RELEASE</td> 323 <td>The version of the currently-executing Android system, in human-readable 324 format. This field MUST have one of the string values defined in [<a 325 href="#resources07">Resources, 7</a>].</td> 326 </tr> 327 <tr> 328 <td>android.os.Build.VERSION.SDK</td> 329 <td>The version of the currently-executing Android system, in a format 330 accessible to third-party application code. For Android 4.2, this 331 field MUST have the integer value 17.</td> 332 </tr> 333 <tr> 334 <td>android.os.Build.VERSION.SDK_INT</td> 335 <td>The version of the currently-executing Android system, in a format 336 accessible to third-party application code. For Android 4.2, this 337 field MUST have the integer value 17.</td> 338 </tr> 339 <tr> 340 <td>android.os.Build.VERSION.INCREMENTAL</td> 341 <td>A value chosen by the device implementer designating the specific build of 342 the currently-executing Android system, in human-readable format. This value 343 MUST NOT be re-used for different builds made available to end users. A typical use 344 of this field is to indicate which build number or source-control change 345 identifier was used to generate the build. There are no requirements on the 346 specific format of this field, except that it MUST NOT be null or the empty 347 string ("").</td> 348 </tr> 349 <tr> 350 <td>android.os.Build.BOARD</td> 351 <td>A value chosen by the device implementer identifying the specific internal 352 hardware used by the device, in human-readable format. A possible use of this 353 field is to indicate the specific revision of the board powering the device. 354 The value of this field MUST be encodable as 7-bit ASCII and match the regular expression 355 <code>"^[a-zA-Z0-9.,_-]+$"</code>.</td> 356 </tr> 357 <tr> 358 <td>android.os.Build.BRAND</td> 359 <td>A value chosen by the device implementer identifying the name of the 360 company, organization, individual, etc. who produced the device, in 361 human-readable format. A possible use of this field is to indicate the OEM 362 and/or carrier who sold the device. The value of this field MUST be 363 encodable as 7-bit ASCII and match the regular expression 364 <code>"^[a-zA-Z0-9.,_-]+$"</code>. 365 </td> 366 </tr> 367 <tr> 368 <td>android.os.Build.CPU_ABI</td> 369 <td>The name of the instruction set (CPU type + ABI convention) of native code. 370 See <a href="#section-3.3">Section 3.3: Native API Compatibility</a>. 371 </td> 372 </tr> 373 <tr> 374 <td>android.os.Build.CPU_ABI2</td> 375 <td>The name of the second instruction set (CPU type + ABI convention) of native code. 376 See <a href="#section-3.3">Section 3.3: Native API Compatibility</a>. 377 </td> 378 </tr> 379 <tr> 380 <td>android.os.Build.DEVICE</td> 381 <td>A value chosen by the device implementer identifying the specific 382 configuration or revision of the body (sometimes called "industrial design") 383 of the device. The value of this field MUST be encodable as 7-bit ASCII and 384 match the regular expression <code>"^[a-zA-Z0-9.,_-]+$"</code>.</td> 385 </tr> 386 <tr> 387 <td>android.os.Build.FINGERPRINT</td> 388 <td>A string that uniquely identifies this build. It SHOULD be reasonably 389 human-readable. It MUST follow this template: 390 <br/><code>$(BRAND)/$(PRODUCT)/$(DEVICE):$(VERSION.RELEASE)/$(ID)/$(VERSION.INCREMENTAL):$(TYPE)/$(TAGS)</code><br/> 391 For example: 392 <br/><code>acme/mydevice/generic:4.2/JRN53/3359:userdebug/test-keys</code><br/> 393 The fingerprint MUST NOT include whitespace characters. If other fields included in the 394 template above have whitespace characters, they MUST be replaced in the build 395 fingerprint with another character, such as the underscore ("_") character. 396 The value of this field MUST be encodable as 7-bit ASCII.</td> 397 </tr> 398 <tr> 399 <td>android.os.Build.HARDWARE</td> 400 <td>The name of the hardware (from the kernel command line or /proc). It SHOULD be 401 reasonably human-readable. The value of this field MUST be encodable as 7-bit ASCII and 402 match the regular expression <code>"^[a-zA-Z0-9.,_-]+$"</code>.</td> 403 </tr> 404 <tr> 405 <td>android.os.Build.HOST</td> 406 <td>A string that uniquely identifies the host the build was built on, in 407 human readable format. There are no requirements on the specific format of 408 this field, except that it MUST NOT be null or the empty string ("").</td> 409 </tr> 410 <tr> 411 <td>android.os.Build.ID</td> 412 <td>An identifier chosen by the device implementer to refer to a specific 413 release, in human readable format. This field can be the same as 414 android.os.Build.VERSION.INCREMENTAL, but SHOULD be a value sufficiently 415 meaningful for end users to distinguish between software builds. The value of 416 this field MUST be encodable as 7-bit ASCII and match the regular expression 417 <code>"^[a-zA-Z0-9.,_-]+$"</code>. 418 </td> 419 </tr> 420 <tr> 421 <td>android.os.Build.MANUFACTURER</td> 422 <td>The trade name of the Original Equipment Manufacturer (OEM) of the product. 423 There are no requirements on the specific format of this field, except that it 424 MUST NOT be null or the empty string ("").</td> 425 </tr> 426 <tr> 427 <td>android.os.Build.MODEL</td> 428 <td>A value chosen by the device implementer containing the name of the device 429 as known to the end user. This SHOULD be the same name under which the device 430 is marketed and sold to end users. There are no requirements on the specific 431 format of this field, except that it MUST NOT be null or the empty string 432 ("").</td> 433 </tr> 434 <tr> 435 <td>android.os.Build.PRODUCT</td> 436 <td>A value chosen by the device implementer containing the development name 437 or code name of the product (SKU). MUST be human-readable, but is not necessarily 438 intended for view by end users. The value of this field MUST be encodable as 7-bit 439 ASCII and match the regular expression 440 <code>"^[a-zA-Z0-9.,_-]+$"</code>.</td> 441 </tr> 442 <tr> 443 <td>android.os.Build.SERIAL</td> 444 <td>A hardware serial number, if available. The value of this field MUST be encodable 445 as 7-bit ASCII and match the regular expression 446 <code>"^([a-zA-Z0-9]{0,20})$"</code>.</td> 447 </tr> 448 <tr> 449 <td>android.os.Build.TAGS</td> 450 <td>A comma-separated list of tags chosen by the device implementer that 451 further distinguish the build. For example, "unsigned,debug". The value of 452 this field MUST be encodable as 7-bit ASCII and match the regular expression 453 <code>"^[a-zA-Z0-9.,_-]+$"</code>.</td> 454 </tr> 455 <tr> 456 <td>android.os.Build.TIME</td> 457 <td>A value representing the timestamp of when the build occurred.</td> 458 </tr> 459 <tr> 460 <td>android.os.Build.TYPE</td> 461 <td>A value chosen by the device implementer specifying the runtime 462 configuration of the build. This field SHOULD have one of the values 463 corresponding to the three typical Android runtime configurations: "user", 464 "userdebug", or "eng". The value of this field MUST be 465 encodable as 7-bit ASCII and match the regular expression 466 <code>"^[a-zA-Z0-9.,_-]+$"</code>.</td> 467 </tr> 468 <tr> 469 <td>android.os.Build.USER</td> 470 <td>A name or user ID of the user (or automated user) that generated the 471 build. There are no requirements on the specific format of this field, except 472 that it MUST NOT be null or the empty string ("").</td> 473 </tr> 474 </tbody> 475 </table> 476 <a name="section-3.2.3"></a><h4>3.2.3. Intent Compatibility</h4> 477 <p> 478 Device implementations MUST honor Android's loose-coupling Intent system, as 479 described in the sections below. By "honored", it is meant that the device 480 implementer MUST provide an Android Activity or Service that specifies a 481 matching Intent filter and binds to and implements correct behavior for each 482 specified Intent pattern.</p> 483 <a name="section-3.2.3.1"></a><h4>3.2.3.1. Core Application Intents</h4> 484 <p>The Android upstream project defines a number of core applications, such as 485 contacts, calendar, photo gallery, music player, and so on. Device implementers 486 MAY replace these applications with alternative versions.</p> 487 <p>However, any such alternative versions MUST honor the same Intent patterns 488 provided by the upstream project. For example, if a device contains an 489 alternative music player, it must still honor the Intent pattern issued by 490 third-party applications to pick a song.</p> 491 <p>The following applications are considered core Android system 492 applications:</p> 493 <ul> 494 <li>Desk Clock</li> 495 <li>Browser</li> 496 <li>Calendar</li> 497 <li>Contacts</li> 498 <!--<li>Email</li>--> 499 <li>Gallery</li> 500 <li>GlobalSearch</li> 501 <li>Launcher</li> 502 <!-- <li>LivePicker (that is, the Live Wallpaper picker application; MAY be omitted 503 if the device does not support Live Wallpapers, per Section 3.8.5.)</li> --> 504 <!-- <li>Messaging (AKA "Mms")</li> --> 505 <li>Music</li> 506 <!-- <li>Phone</li> --> 507 <li>Settings</li> 508 <!-- <li>SoundRecorder</li> --> 509 </ul> 510 <p>The core Android system applications include various Activity, or Service 511 components that are considered "public". That is, the attribute 512 "android:exported" may be absent, or may have the value "true".</p> 513 <p>For every Activity or Service defined 514 in one of the core Android system apps that is not marked as non-public via an 515 android:exported attribute with the value "false", device implementations MUST 516 include a compontent of the same type implementing the same Intent filter 517 patterns as the core Android system app.</p> 518 <p>In other words, a device implementation MAY replace core Android system 519 apps; however, if it does, the device implementation MUST support all Intent 520 patterns defined by each core Android system app being replaced.</p> 521 <a name="section-3.2.3.2"></a><h4>3.2.3.2. Intent Overrides</h4> 522 <p>As Android is an extensible platform, device implementations MUST allow each 523 Intent pattern referenced in Section 3.2.3.2 to be overridden by third-party 524 applications. The upstream Android open source implementation allows this by 525 default; device implementers MUST NOT attach special privileges to system 526 applications' use of these Intent patterns, or prevent third-party 527 applications from binding to and assuming control of these patterns. This 528 prohibition specifically includes but is not limited to disabling the 529 "Chooser" user interface which allows the user to select between multiple 530 applications which all handle the same Intent pattern.</p> 531 <p>However, device implementations MAY provide default activities for specific 532 URI patterns (eg. http://play.google.com) if the default activity provides a 533 more specific filter for the data URI. For example, an intent filter specifying 534 the data URI "http://www.android.com" is more specific than the browser filter 535 for "http://". Device implementations MUST provide a user interface for users 536 to modify the default activity for intents.</p> 537 538 <a name="section-3.2.3.3"></a><h4>3.2.3.3. Intent Namespaces</h4> 539 <p>Device implementations MUST NOT include any Android component that honors any 540 new Intent or Broadcast Intent patterns using an ACTION, CATEGORY, or other 541 key string in the android.* or com.android.* namespace. Device implementers 542 MUST NOT include any Android components that honor any new Intent or Broadcast 543 Intent patterns using an ACTION, CATEGORY, or other key string in a package 544 space belonging to another organization. Device implementers MUST NOT alter or 545 extend any of the Intent patterns used by the core apps listed in Section 546 3.2.3.1. Device implementations MAY include Intent patterns using 547 namespaces clearly and obviously associated with their own organization.</p> 548 <p>This prohibition is analogous to that specified for Java language classes 549 in Section 3.6.</p> 550 <a name="section-3.2.3.4"></a><h4>3.2.3.4. Broadcast Intents</h4> 551 <p>Third-party applications rely on the platform to broadcast certain Intents 552 to notify them of changes in the hardware or software environment. 553 Android-compatible devices MUST broadcast the public broadcast Intents in 554 response to appropriate system events. Broadcast Intents are described in the 555 SDK documentation.</p> 556 557 <a name="section-3.3"></a><h3>3.3. Native API Compatibility</h3> 558 <a name="section-3.3.1"></a><h4>3.3.1 Application Binary Interfaces</h4> 559 <p>Managed code running in Dalvik can call into native code provided in the 560 application .apk file as an ELF .so file compiled for the appropriate device 561 hardware architecture. As native code is highly dependent on the underlying 562 processor technology, Android defines a number of Application Binary 563 Interfaces (ABIs) in the Android NDK, in the file 564 <code>docs/CPU-ARCH-ABIS.html</code>. If a device implementation is compatible 565 with one or more defined ABIs, it SHOULD implement compatibility with the 566 Android NDK, as below.</p> 567 <p>If a device implementation includes support for an Android ABI, it:</p> 568 <ul> 569 <li>MUST include support for code running in the managed environment to call 570 into native code, using the standard Java Native Interface (JNI) 571 semantics.</li> 572 <li>MUST be source-compatible (i.e. header compatible) and binary-compatible 573 (for the ABI) with each required library in the list below</li> 574 <li>MUST accurately report the native Application Binary Interface (ABI) 575 supported by the device, via the <code>android.os.Build.CPU_ABI</code> 576 API</li> 577 <li>MUST report only those ABIs documented in the latest version of the 578 Android NDK, in the file <code>docs/CPU-ARCH-ABIS.txt</code></li> 579 <li>SHOULD be built using the source code and header files available in the 580 upstream Android open source project</li> 581 </ul> 582 <p>The following native code APIs MUST be available to apps that include 583 native code:</p> 584 <ul> 585 <li>libc (C library)</li> 586 <li>libm (math library)</li> 587 <li>Minimal support for C++</li> 588 <li>JNI interface</li> 589 <li>liblog (Android logging)</li> 590 <li>libz (Zlib compression)</li> 591 <li>libdl (dynamic linker)</li> 592 <li>libGLESv1_CM.so (OpenGL ES 1.0)</li> 593 <li>libGLESv2.so (OpenGL ES 2.0)</li> 594 <li>libEGL.so (native OpenGL surface management)</li> 595 <li>libjnigraphics.so</li> 596 <li>libOpenSLES.so (OpenSL ES 1.0.1 audio support)</li> 597 <li>libOpenMAXAL.so (OpenMAX AL 1.0.1 support)</li> 598 <li>libandroid.so (native Android activity support)</li> 599 <li>Support for OpenGL, as described below</li> 600 </ul> 601 <p>Note that future releases of the Android NDK may introduce support for 602 additional ABIs. If a device implementation is not compatible with an existing 603 predefined ABI, it MUST NOT report support for any ABI at all.</p> 604 <p>Native code compatibility is challenging. For this reason, it should be 605 repeated that device implementers are VERY strongly encouraged to use the 606 upstream implementations of the libraries listed above to help ensure 607 compatibility.</p> 608 609 <a name="section-3.4"></a><h3>3.4. Web Compatibility</h3> 610 <a name="section-3.4.1"></a><h4>3.4.1. WebView Compatibility</h4> 611 <p>The Android Open Source implementation uses the WebKit rendering engine to 612 implement the <code>android.webkit.WebView</code>. Because it is not feasible 613 to develop a comprehensive test suite for a web rendering system, device 614 implementers MUST use the specific upstream build of WebKit in the WebView 615 implementation. Specifically:</p> 616 <ul> 617 <li>Device implementations' <code>android.webkit.WebView</code> 618 implementations MUST be based on the 534.30 WebKit build from the upstream 619 Android Open Source tree for Android 4.2. This build includes a specific set 620 of functionality and security fixes for the WebView. Device implementers MAY 621 include customizations to the WebKit implementation; however, any such 622 customizations MUST NOT alter the behavior of the WebView, including rendering 623 behavior.</li> 624 <li>The user agent string reported by the WebView MUST be in this format:<br/> 625 <code>Mozilla/5.0 (Linux; U; Android $(VERSION); $(LOCALE); $(MODEL) Build/$(BUILD)) AppleWebKit/534.30 (KHTML, like Gecko) Version/4.2 Mobile Safari/534.30</code> 626 <ul> 627 <li>The value of the $(VERSION) string MUST be the same as the value for <code>android.os.Build.VERSION.RELEASE</code></li> 628 <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> 629 <li>The value of the $(MODEL) string MUST be the same as the value for <code>android.os.Build.MODEL</code></li> 630 <li>The value of the $(BUILD) string MUST be the same as the value for <code>android.os.Build.ID</code></li> 631 <li>Device implementations MAY omit <code>Mobile</code> in the user agent string</li> 632 </ul> 633 </li> 634 </ul> 635 <p>The WebView component SHOULD include support for as much of HTML5 [<a 636 href="#resources11">Resources, 11</a>] as possible. 637 Minimally, device implementations MUST support each of these APIs associated 638 with HTML5 in the WebView:</p> 639 <ul> 640 <li>application cache/offline operation [<a href="#resources12">Resources, 12</a>]</li> 641 <li>the <video> tag [<a href="#resources13">Resources, 13</a>]</li> 642 <li>geolocation [<a href="#resources14">Resources, 14</a>]</li> 643 </ul> 644 <p>Additionally, device implementations MUST support the HTML5/W3C webstorage 645 API [<a href="#resources15">Resources, 15</a>], and SHOULD support the 646 HTML5/W3C IndexedDB API [<a href="#resources16">Resources, 16</a>]. <i>Note 647 that as the web development standards bodies are transitioning to favor 648 IndexedDB over webstorage, IndexedDB is expected to become a required 649 component in a future version of Android.</i></p> 650 <p>HTML5 APIs, like all JavaScript APIs, MUST be disabled by default in a 651 WebView, unless the developer explicitly enables them via the usual Android 652 APIs.</p> 653 654 <a name="section-3.4.2"></a><h4>3.4.2. Browser Compatibility</h4> 655 <p>Device implementations MUST include a standalone Browser application for 656 general user web browsing. The standalone Browser MAY be based on a 657 browser technology other than WebKit. However, even if an alternate Browser 658 application is used, the <code>android.webkit.WebView</code> component 659 provided to third-party applications MUST be based on WebKit, as described in 660 Section 3.4.1.</p> 661 <p>Implementations MAY ship a custom user agent string in the standalone 662 Browser application.</p> 663 <p>The standalone Browser application (whether based on the upstream 664 WebKit Browser application or a third-party replacement) SHOULD include support 665 for as much of HTML5 [<a href="#resources11">Resources, 11</a>] as possible. 666 Minimally, device implementations MUST support each of these APIs associated 667 with HTML5:</p> 668 <ul> 669 <li>application cache/offline operation [<a href="#resources12">Resources, 12</a>]</li> 670 <li>the <video> tag [<a href="#resources13">Resources, 13</a>]</li> 671 <li>geolocation [<a href="#resources14">Resources, 14</a>]</li> 672 </ul> 673 <p>Additionally, device implementations MUST support the HTML5/W3C webstorage 674 API [<a href="#resources15">Resources, 15</a>], and SHOULD support the 675 HTML5/W3C IndexedDB API [<a href="#resources16">Resources, 16</a>]. <i>Note 676 that as the web development standards bodies are transitioning to favor 677 IndexedDB over webstorage, IndexedDB is expected to become a required 678 component in a future version of Android.</i></p> 679 680 <a name="section-3.5"></a><h3>3.5. API Behavioral Compatibility</h3> 681 <p>The behaviors of each of the API types (managed, soft, native, and web) 682 must be consistent with the preferred implementation of the upstream Android 683 open source project [<a href="#resources03">Resources, 3</a>]. Some specific areas 684 of compatibility are:</p> 685 <ul> 686 <li>Devices MUST NOT change the behavior or semantics of a standard Intent</li> 687 <li>Devices MUST NOT alter the lifecycle or lifecycle semantics of a 688 particular type of system component (such as Service, Activity, 689 ContentProvider, etc.)</li> 690 <li>Devices MUST NOT change the semantics of a standard permission</li> 691 </ul> 692 <p>The above list is not comprehensive. The Compatibility Test Suite (CTS) 693 tests significant portions of the platform for behavioral compatibility, but 694 not all. It is the responsibility of the implementer to ensure behavioral 695 compatibility with the Android Open Source Project. For this reason, device 696 implementers SHOULD use the source code available via the Android Open Source 697 Project where possible, rather than re-implement significant parts of the 698 system.</p> 699 700 701 <a name="section-3.6"></a><h3>3.6. API Namespaces</h3> 702 <p>Android follows the package and class namespace conventions defined by the 703 Java programming language. To ensure compatibility with third-party 704 applications, device implementers MUST NOT make any prohibited modifications 705 (see below) to these package namespaces:</p> 706 <ul> 707 <li>java.*</li> 708 <li>javax.*</li> 709 <li>sun.*</li> 710 <li>android.*</li> 711 <li>com.android.*</li> 712 </ul> 713 <p>Prohibited modifications include:</p> 714 <ul> 715 <li>Device implementations MUST NOT modify the publicly exposed APIs on the 716 Android platform by changing any method or class signatures, or by removing 717 classes or class fields.</li> 718 <li>Device implementers MAY modify the underlying implementation of the APIs, 719 but such modifications MUST NOT impact the stated behavior and Java-language 720 signature of any publicly exposed APIs.</li> 721 <li>Device implementers MUST NOT add any publicly exposed elements (such as 722 classes or interfaces, or fields or methods to existing classes or interfaces) 723 to the APIs above.</li> 724 </ul> 725 <p>A "publicly exposed element" is any construct which is not decorated with 726 the "@hide" marker as used in the upstream Android source code. In other 727 words, device implementers MUST NOT expose new APIs or alter existing APIs in 728 the namespaces noted above. Device implementers MAY make internal-only 729 modifications, but those modifications MUST NOT be advertised or otherwise 730 exposed to developers.</p> 731 <p>Device implementers MAY add custom APIs, but any such APIs MUST NOT be in a 732 namespace owned by or referring to another organization. For instance, device 733 implementers MUST NOT add APIs to the com.google.* or similar namespace; only 734 Google may do so. Similarly, Google MUST NOT add APIs to other companies' 735 namespaces. Additionally, if a device implementation includes custom APIs 736 outside the standard Android namespace, those APIs MUST be packaged in an 737 Android shared library so that only apps that explicitly use them (via the 738 <code><uses-library></code> mechanism) are affected by the increased 739 memory usage of such APIs.</p> 740 <p>If a device implementer proposes to improve one of the package namespaces 741 above (such as by adding useful new functionality to an existing API, or 742 adding a new API), the implementer SHOULD visit source.android.com and begin 743 the process for contributing changes and code, according to the information on 744 that site.</p> 745 <p>Note that the restrictions above correspond to standard conventions for 746 naming APIs in the Java programming language; this section simply aims to 747 reinforce those conventions and make them binding through inclusion in this 748 compatibility definition.</p> 749 750 <a name="section-3.7"></a><h3>3.7. Virtual Machine Compatibility</h3> 751 <p>Device implementations MUST support the full Dalvik Executable (DEX) 752 bytecode specification and Dalvik Virtual Machine semantics [<a 753 href="#resources17">Resources, 17</a>].</p> 754 <p>Device implementations MUST configure Dalvik to allocate memory in 755 accordance with the upstream Android platform, and as specified by the following 756 table. (See <a href="#section-7.1.1">Section 7.1.1</a> for screen size and screen 757 density definitions.)</p> 758 759 <p>Note that memory values specified below are considered minimum values, 760 and device implementations MAY allocate more memory per application.</p> 761 <table> 762 <tbody> 763 <tr> 764 <td><b>Screen Size</b></td> 765 <td><b>Screen Density</b></td> 766 <td><b>Application Memory</b></td> 767 </tr> 768 <tr> 769 <td>small / normal / large</td> 770 <td>ldpi / mdpi</td> 771 <td>16MB</td> 772 </tr> 773 <tr> 774 <td>small / normal / large</td> 775 <td>tvdpi / hdpi</td> 776 <td>32MB</td> 777 </tr> 778 <tr> 779 <td>small / normal / large</td> 780 <td>xhdpi</td> 781 <td>64MB</td> 782 </tr> 783 <tr> 784 <td>xlarge</td> 785 <td>mdpi</td> 786 <td>32MB</td> 787 </tr> 788 <tr> 789 <td>xlarge</td> 790 <td>tvdpi / hdpi</td> 791 <td>64MB</td> 792 </tr> 793 <tr> 794 <td>xlarge</td> 795 <td>xhdpi</td> 796 <td>128MB</td> 797 </tr> 798 </tbody> 799 </table> 800 801 <a name="section-3.8"></a><h3>3.8. User Interface Compatibility</h3> 802 <a name="section-3.8.1"></a><h4>3.8.1. Widgets</h4> 803 <p>Android defines a component type and corresponding API and lifecycle that 804 allows applications to expose an "AppWidget" to the end user [<a 805 href="#resources18">Resources, 18</a>]. 806 The Android Open Source reference release includes a Launcher application that 807 includes user interface affordances allowing the user to add, view, and remove 808 AppWidgets from the home screen.</p> 809 <p>Device implementations MAY substitute an alternative to the reference Launcher 810 (i.e. home screen). Alternative Launchers SHOULD include built-in support for 811 AppWidgets, and expose user interface affordances to add, configure, view, and 812 remove AppWidgets directly within the Launcher. Alternative Launchers MAY omit 813 these user interface elements; however, if they are omitted, the device 814 implementation MUST provide a separate application accessible from the Launcher 815 that allows users to add, configure, view, and remove AppWidgets.</p> 816 <p>Device implementations MUST be capable of rendering widgets that are 4 x 4 817 in the standard grid size. (See the App Widget Design Guidelines in the Android 818 SDK documentation [<a href="#resources18">Resources, 18</a>] for details.</p> 819 <p> 820 <a name="section-3.8.2"></a><h4>3.8.2. Notifications</h4> 821 <p>Android includes APIs that allow developers to notify users of notable 822 events [<a href="#resources19">Resources, 19</a>], using hardware and software 823 features of the device.</p> 824 <p>Some APIs allow applications to perform notifications or attract attention 825 using hardware, specifically sound, vibration, and light. Device implementations 826 MUST support notifications that use hardware features, as described in the SDK 827 documentation, and to the extent possible with the device implementation 828 hardware. For instance, if a device implementation includes a vibrator, it 829 MUST correctly implement the vibration APIs. If a device implementation lacks 830 hardware, the corresponding APIs MUST be implemented as no-ops. Note that this 831 behavior is further detailed in <a href="#section-7">Section 7.</a></p> 832 <p>Additionally, the implementation MUST correctly render all resources 833 (icons, sound files, etc.) provided for in the APIs [<a 834 href="#resources20">Resources, 20</a>], or in the 835 Status/System Bar icon style guide [<a href="#resources21">Resources, 21</a>]. 836 Device implementers MAY provide an alternative user experience for 837 notifications than that provided by the reference Android Open Source 838 implementation; however, such alternative notification systems MUST support 839 existing notification resources, as above.</p> 840 <p>Android 4.2 includes support for rich notifications, such as interactive 841 Views for ongoing notifications. Device implementations MUST properly display 842 and execute rich notifications, as documented in the Android APIs.</p> 843 <a name="section-3.8.3"></a><h4>3.8.3. Search</h4> 844 <p>Android includes APIs [<a href="#resources22">Resources, 22</a>] that allow 845 developers to incorporate search into their applications, and expose their 846 application's data into the global system search. Generally speaking, this 847 functionality consists of a single, system-wide user interface that allows users 848 to enter queries, displays suggestions as users type, and displays results. The 849 Android APIs allow developers to reuse this interface to provide search within 850 their own apps, and allow developers to supply results to the common global 851 search user interface.</p> 852 <p>Device implementations MUST include a single, shared, system-wide search 853 user interface capable of real-time suggestions in response to user input. 854 Device implementations MUST implement the APIs that allow developers to reuse 855 this user interface to provide search within their own applications. Device 856 implementations MUST implement the APIs that allow third-party applications to 857 add suggestions to the search box when it is run in global search mode. If no 858 third-party applications are installed that make use of this functionality, 859 the default behavior SHOULD be to display web search engine results and 860 suggestions.</p> 861 <a name="section-3.8.4"></a><h4>3.8.4. Toasts</h4> 862 <p>Applications can use the "Toast" API (defined in [<a 863 href="#resources23">Resources, 23</a>]) to 864 display short non-modal strings to the end user, that disappear after a brief 865 period of time. Device implementations MUST display Toasts from applications 866 to end users in some high-visibility manner.</p> 867 868 <a name="section-3.8.5"></a><h4>3.8.5. Themes</h4> 869 <p>Android provides "themes" as a mechanism for applications to apply styles 870 across an entire Activity or application. Android 4.2 includes a "Holo" 871 or "holographic" theme as a set of defined styles for application developers to 872 use if they want to match the Holo theme look and feel as defined by the Android 873 SDK [<a href="#resources24">Resources, 24</a>]. Device implementations MUST NOT 874 alter any of the Holo theme attributes exposed to applications 875 [<a href="#resources25">Resources, 25</a>].</p> 876 <p>Android 4.2 includes a new "Device Default" theme as a set of defined 877 styles for application developers to use if they want to match the look and feel 878 of the device theme as defined by the device implementer. Device implementations 879 MAY modify the DeviceDefault theme attributes exposed to applications 880 [<a href="#resources25">Resources, 25</a>].</p> 881 882 <a name="section-3.8.6"></a><h4>3.8.6. Live Wallpapers</h4> 883 <p>Android defines a component type and corresponding API and lifecycle that 884 allows applications to expose one or more "Live Wallpapers" to the end user 885 [<a href="#resources26">Resources, 26</a>]. Live Wallpapers are animations, 886 patterns, or similar images with limited input capabilities that display as a 887 wallpaper, behind other applications.</p> 888 <p>Hardware is considered capable of reliably running live wallpapers if it 889 can run all live wallpapers, with no limitations on functionality, at a 890 reasonable framerate with no adverse affects on other applications. If 891 limitations in the hardware cause wallpapers and/or applications to crash, 892 malfunction, consume excessive CPU or battery power, or run at unacceptably 893 low frame rates, the hardware is considered incapable of running live 894 wallpaper. As an example, some live wallpapers may use an Open GL 1.0 or 2.0 895 context to render their content. Live wallpaper will not run reliably on 896 hardware that does not support multiple OpenGL contexts because the live 897 wallpaper use of an OpenGL context may conflict with other applications that 898 also use an OpenGL context.</p> 899 <p>Device implementations capable of running live wallpapers reliably as 900 described above SHOULD implement live wallpapers. Device implementations 901 determined to not run live wallpapers reliably as described above MUST NOT 902 implement live wallpapers.</p> 903 <a name="section-3.8.7"></a><h4>3.8.7. Recent Application Display</h4> 904 <p>The upstream Android 4.2 source code includes a user interface for 905 displaying recent applications using a thumbnail image of the application's 906 graphical state at the moment the user last left the application. Device 907 implementations MAY alter or eliminate this user interface; however, a future 908 version of Android is planned to make more extensive use of this 909 functionality. Device implementations are strongly encouraged to use the 910 upstream Android 4.2 user interface (or a similar thumbnail-based interface) 911 for recent applications, or else they may not be compatible with a future 912 version of Android.</p> 913 <a name="section-3.8.8"></a><h4>3.8.8. Input Management Settings</h4> 914 <p>Android 4.2 includes support for Input Management Engines. The Android 4.2 915 APIs allow custom app IMEs to specify user-tunable settings. Device 916 implementations MUST include a way for the user to access IME settings at all 917 times when an IME that provides such user settings is displayed.</p> 918 919 <a name="section-3.8.9"></a><h4>3.8.9. Lock and Home Screen Widgets</h4> 920 <p>Android 4.2 includes support for application widgets that users can embed in the home screen or the lock screen 921 (See the App Widget Design Guidelines in the Android SDK documentation [<a href="#resources69">Resources, 69</a>] for details). 922 Application widgets allow quick access to application data and services without launching a new activity. Widgets declare support 923 for usage on the home screen or the lock screen by declaring the <code>android:widgetCategory</code> manifest tag that tells the system 924 where the widget can be placed. Specifically, device implementations MUST meet the following requirements.</p> 925 <ul> 926 <li>Device implementations MUST support application widgets on the home screen.</li> 927 <li>Device implementations SHOULD support lock screen. If device implementations include support for lock screen 928 then device implementations MUST support application widgets on the lock screen.</li> 929 </ul> 930 931 <a name="section-3.8.10"></a><h4>3.8.10. Lock Screen Media Remote Control</h4> 932 <p>Android 4.2 includes support for Remote Control API that lets media applications integrate with playback controls 933 that are displayed in a remote view like the device lock screen[<a href="#resources74">Resources, 74</a>]. Device implementations MUST 934 include support for embedding remote controls in the device lock screen. 935 </p> 936 <a name="section-3.8.11"></a><h4>3.8.11. Dreams</h4> 937 <p>Android 4.2 includes support for interactive screensavers called Dreams [<a href="#resources76">Resources, 76</a>]. 938 Dreams allows users to interact with applications when a charging device is idle, or docked in a desk dock. Device implementations 939 MUST include support for Dreams and provide a settings option for users to configure Dreams.</p> 940 941 <a name="section-3.9"></a><h3>3.9 Device Administration</h3> 942 <p>Android 4.2 includes features that allow security-aware applications 943 to perform device administration functions at the system level, such as enforcing 944 password policies or performing remote wipe, through the Android Device 945 Administration API [<a href="#resources27">Resources, 27</a>]. Device 946 implementations MUST provide an implementation of the <code>DevicePolicyManager 947 </code> class [<a href="#resources28">Resources, 28</a>], and SHOULD support 948 the full range of device administration policies defined in the Android SDK 949 documentation [<a href="#resources27">Resources, 27</a>]. 950 </p> 951 <p><b>Note:</b> while some of the requirements outlined above are stated as "SHOULD" 952 for Android 4.2, device implementations that support lock screen MUST support device policies to manage widgets 953 on the lock screen as defined in the Android SDK documentation [<a href="#resources27">Resources, 27</a>]. 954 </p> 955 <p><b>Note:</b> while some of the requirements outlined above are stated as "SHOULD" 956 for Android 4.2, the Compatibility Definition for a future version is planned 957 to change these to "MUST". That is, these requirements are optional in Android 958 4.2 but <b>will be required</b> by a future version. Existing and new devices 959 that run Android 4.2 are <b>very strongly encouraged to meet 960 these requirements in Android 4.2</b>, or they will not be able to attain 961 Android compatibility when upgraded to the future version.</p> 962 963 <a name="section-3.10"></a><h3>3.10 Accessibility</h3> 964 <p>Android 4.2 provides an accessibility layer that helps users with disabilities 965 to navigate their devices more easily. In addition, Android 4.2 provides 966 platform APIs that enable accessibility service implementations to receive 967 callbacks for user and system events and generate alternate feedback mechanisms, 968 such as text-to-speech, haptic feedback, and trackball/d-pad navigation 969 [<a href="#resources29">Resources, 29</a>]. Device implementations MUST provide an 970 implementation of the Android accessibility framework consistent with the 971 default Android implementation. Specifically, device implementations MUST meet 972 the following requirements.</p> 973 <ul> 974 <li>Device implementations MUST support third party accessibility service 975 implementations through the <code>android.accessibilityservice</code> 976 APIs [<a href="#resources30">Resources, 30</a>].</li> 977 <li>Device implementations MUST generate <code>AccessibilityEvents</code> 978 and deliver these events to all registered <code>AccessibilityService 979 </code> implementations in a manner consistent with the default Android 980 implementation.</li> 981 <li>Device implementations MUST provide a user-accessible mechanism to enable 982 and disable accessibility services, and MUST display this interface in 983 response to the 984 <code>android.provider.Settings.ACTION_ACCESSIBILITY_SETTINGS</code> 985 intent.</li> 986 </ul> 987 <p>Additionally, device implementations SHOULD provide an implementation 988 of an accessibility service on the device, and SHOULD provide a mechanism 989 for users to enable the accessibility service during device setup. An open 990 source implementation of an accessibility service is available from the Eyes 991 Free project [<a href="#resources31">Resources, 31</a>].</p> 992 993 <a name="section-3.11"></a><h3>3.11 Text-to-Speech</h3> 994 <p>Android 4.2 includes APIs that allow applications to make use of 995 text-to-speech (TTS) services, and allows service providers to provide 996 implementations of TTS services [<a href="#resources32">Resources, 32</a>]. 997 Device implementations MUST meet these requirements related to the Android TTS 998 framework:</p> 999 <ul> 1000 <li>Device implementations MUST support the Android TTS framework APIs and 1001 SHOULD include a TTS engine supporting the languages available on the 1002 device. Note that the upstream Android open source software includes a 1003 full-featured TTS engine implementation.</li> 1004 <li>Device implementations MUST support installation of third-party TTS 1005 engines.</li> 1006 <li>Device implementations MUST provide a user-accessible interface that allows 1007 users to select a TTS engine for use at the system level.</li> 1008 </ul> 1009 1010 <a name="section-4"></a><h2>4. Application Packaging Compatibility</h2> 1011 <p>Device implementations MUST install and run Android ".apk" files as 1012 generated by the "aapt" tool included in the official Android SDK [<a 1013 href="#resources33">Resources, 33</a>].</p> 1014 <p>Devices implementations MUST NOT extend either the .apk [<a 1015 href="#resources34">Resources, 34</a>], Android Manifest [<a 1016 href="#resources35">Resources, 35</a>], 1017 Dalvik bytecode [<a href="#resources17">Resources, 17</a>], or renderscript 1018 bytecode formats in such a way that would prevent those files from installing 1019 and running correctly on other compatible devices. Device implementers SHOULD 1020 use the reference upstream implementation of Dalvik, and the reference 1021 implementation's package management system.</p> 1022 1023 <a name="section-5"></a><h2>5. Multimedia Compatibility</h2> 1024 <p>Device implementations MUST include at least one form of audio output, such as 1025 speakers, headphone jack, external speaker connection, etc.</p> 1026 <a name="section-5.1"></a><h3>5.1. Media Codecs</h3> 1027 <p>Device implementations MUST support the core media formats specified 1028 in the Android SDK documentation [<a href="#resources58">Resources, 58</a>] except 1029 where explicitly permitted in this document. Specifically, device implementations 1030 MUST support the media formats, encoders, decoders, file types and container 1031 formats defined in the tables below. All of these codecs are provided as 1032 software implementations in the preferred Android implementation from the Android 1033 Open Source Project.</p> 1034 1035 <p><strong>Please note that neither Google nor the Open Handset Alliance make any 1036 representation that these codecs are unencumbered by third-party patents. 1037 Those intending to use this source code in hardware or software products are 1038 advised that implementations of this code, including in open source software 1039 or shareware, may require patent licenses from the relevant patent 1040 holders.</strong></p> 1041 1042 <p>Note that these tables do not list specific bitrate requirements for 1043 most video codecs because current device hardware does not necessarily support 1044 bitrates that map exactly to the required bitrates specified by the relevant 1045 standards. Instead, device implementations SHOULD support the highest bitrate 1046 practical on the hardware, up to the limits defined by the specifications.</p> 1047 <div style="page-break-before: always;"></div> 1048 <table> 1049 <tbody> 1050 1051 <tr> 1052 <th>Type</th> 1053 <th>Format / Codec</th> 1054 <th>Encoder</th> 1055 <th>Decoder</th> 1056 <th>Details</th> 1057 <th>File Type(s) / Container Formats</th> 1058 </tr> 1059 1060 <tr> 1061 <td rowspan="11">Audio</td> 1062 <td>MPEG-4 AAC Profile (AAC LC)</td> 1063 <td style="text-align: center;">REQUIRED<br/> 1064 <small>Required for device implementations that include microphone hardware 1065 and define <code>android.hardware.microphone</code>.</small></td> 1066 <td style="text-align: center;">REQUIRED</td> 1067 <td rowspan="1"> Support for mono/stereo/5.0/5.1* content with standard sampling rates from 8 to 48 kHz.</td> 1068 <td rowspan="4"> 1069 <ul> 1070 <li>3GPP (.3gp)</li> 1071 <li>MPEG-4 (.mp4, .m4a)</li> 1072 <li>ADTS raw AAC (.aac, decode in Android 3.1+, encode in Android 4.0+, ADIF not supported)</li> 1073 <li>MPEG-TS (.ts, not seekable, Android 3.0+)</li> 1074 </ul> 1075 </td> 1076 </tr> 1077 1078 <tr> 1079 <td>MPEG-4 HE AAC Profile (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/5.0/5.1* content with standard sampling rates from 16 to 48 kHz.</td> 1083 </tr> 1084 1085 <tr> 1086 <td>MPEG-4 HE AAC v2 Profile (enhanced AAC+)</td> 1087 <td> </td> 1088 <td style="text-align: center;">REQUIRED</td> 1089 <td>Support for mono/stereo/5.0/5.1* content with standard sampling rates from 16 to 48 kHz.</td> 1090 </tr> 1091 1092 <tr> 1093 <td>MPEG-4 Audio Object Type ER AAC ELD (Enhanced Low Delay AAC)</td> 1094 <td>REQUIRED for device implementations that include microphone hardware and define android.hardware.microphone</td> 1095 <td style="text-align: center;">REQUIRED</td> 1096 <td>Support for mono/stereo content with standard 1097 sampling rates from 16 to 48 kHz.</td> 1098 </tr> 1099 1100 <tr> 1101 <td>AMR-NB</td> 1102 <td style="text-align: center;">REQUIRED<br/> 1103 <small>Required for device implementations that include microphone hardware 1104 and define <code>android.hardware.microphone</code>.</small></td> 1105 <td style="text-align: center;">REQUIRED</td> 1106 <td>4.75 to 12.2 kbps sampled @ 8kHz</td> 1107 <td>3GPP (.3gp) 1108 </td> 1109 </tr> 1110 1111 <tr> 1112 <td>AMR-WB</td> 1113 <td style="text-align: center;">REQUIRED<br/> 1114 <small>Required for device implementations that include microphone hardware 1115 and define <code>android.hardware.microphone</code>.</small></td> 1116 <td style="text-align: center;">REQUIRED</td> 1117 <td>9 rates from 6.60 kbit/s to 23.85 kbit/s sampled @ 16kHz</td> 1118 <td>3GPP (.3gp)</td> 1119 </tr> 1120 1121 <tr> 1122 <td>FLAC</td> 1123 <td> </td> 1124 <td style="text-align: center;">REQUIRED<br/><small>(Android 3.1+)</small></td> 1125 <td>Mono/Stereo (no multichannel). Sample rates up to 48 kHz (but up to 44.1 1126 kHz is recommended on devices with 44.1 kHz output, as the 48 to 44.1 kHz 1127 downsampler does not include a low-pass filter). 16-bit recommended; 1128 no dither applied for 24-bit. 1129 </td> 1130 <td>FLAC (.flac) only</td> 1131 </tr> 1132 1133 <tr> 1134 <td>MP3</td> 1135 <td> </td> 1136 <td style="text-align: center;">REQUIRED</td> 1137 <td>Mono/Stereo 8-320Kbps constant (CBR) or variable bit-rate (VBR) 1138 </td> 1139 <td>MP3 (.mp3)</td> 1140 </tr> 1141 1142 <tr> 1143 <td>MIDI</td> 1144 <td> </td> 1145 <td style="text-align: center;">REQUIRED</td> 1146 <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> 1147 <td> 1148 <ul> 1149 <li>Type 0 and 1 (.mid, .xmf, .mxmf)</li> 1150 <li>RTTTL/RTX (.rtttl, .rtx)</li> 1151 <li>OTA (.ota)</li> 1152 <li>iMelody (.imy)</li> 1153 </ul> 1154 </td> 1155 </tr> 1156 1157 <tr> 1158 <td>Vorbis</td> 1159 <td> </td> 1160 <td style="text-align: center;">REQUIRED</td> 1161 <td> </td> 1162 <td> 1163 <ul> 1164 <li>Ogg (.ogg)</li> 1165 <li>Matroska (.mkv)</li> 1166 </ul> 1167 </td> 1168 </tr> 1169 1170 <tr> 1171 <td>PCM/WAVE</td> 1172 <td style="text-align: center;">REQUIRED</td> 1173 <td style="text-align: center;">REQUIRED</td> 1174 <td>8-bit and 16-bit linear PCM** (rates up to limit of hardware).Devices MUST support sampling rates 1175 for raw PCM recording at 8000,16000 and 44100 Hz frequencies</td> 1176 <td>WAVE (.wav)</td> 1177 </tr> 1178 1179 <tr> 1180 <td rowspan="5">Image</td> 1181 <td>JPEG</td> 1182 <td style="text-align: center;">REQUIRED</td> 1183 <td style="text-align: center;">REQUIRED</td> 1184 <td>Base+progressive</td> 1185 <td>JPEG (.jpg)</td> 1186 </tr> 1187 1188 <tr> 1189 <td>GIF</td> 1190 <td> </td> 1191 <td style="text-align: center;">REQUIRED</td> 1192 <td> </td> 1193 <td>GIF (.gif)</td> 1194 </tr> 1195 1196 <tr> 1197 <td>PNG</td> 1198 <td style="text-align: center;">REQUIRED</td> 1199 <td style="text-align: center;">REQUIRED</td> 1200 <td> </td> 1201 <td>PNG (.png)</td> 1202 </tr> 1203 1204 <tr> 1205 <td>BMP</td> 1206 <td> </td> 1207 <td style="text-align: center;">REQUIRED</td> 1208 <td> </td> 1209 <td>BMP (.bmp)</td> 1210 </tr> 1211 1212 1213 <tr> 1214 <td>WEBP</td> 1215 <td style="text-align: center;">REQUIRED</td> 1216 <td style="text-align: center;">REQUIRED</td> 1217 <td> </td> 1218 <td>WebP (.webp)</td> 1219 </tr> 1220 1221 <tr> 1222 <td rowspan="4">Video</td> 1223 <td>H.263</td> 1224 <td style="text-align: center;">REQUIRED<br/> 1225 <small>Required for device implementations that include camera hardware 1226 and define <code>android.hardware.camera</code> or 1227 <code>android.hardware.camera.front</code>.</small></td> 1228 <td style="text-align: center;">REQUIRED</td> 1229 <td> </td> 1230 <td> 1231 <ul> 1232 <li>3GPP (.3gp)</li> 1233 <li>MPEG-4 (.mp4)</li> 1234 </ul> 1235 </td> 1236 </tr> 1237 1238 <tr> 1239 <td>H.264 AVC</td> 1240 <td style="text-align: center;">REQUIRED<br/> 1241 <small>Required for device implementations that include camera hardware 1242 and define <code>android.hardware.camera</code> or 1243 <code>android.hardware.camera.front</code>.</small></td> 1244 <td style="text-align: center;">REQUIRED</td> 1245 <td>Baseline Profile (BP)</td> 1246 <td> 1247 <ul> 1248 <li>3GPP (.3gp)</li> 1249 <li>MPEG-4 (.mp4)</li> 1250 <li>MPEG-TS (.ts, AAC audio only, not seekable, Android 3.0+)</li> 1251 </ul> 1252 </td> 1253 </tr> 1254 1255 <tr> 1256 <td>MPEG-4 SP</td> 1257 <td> </td> 1258 <td style="text-align: center;">REQUIRED</td> 1259 <td> </td> 1260 <td>3GPP (.3gp)</td> 1261 </tr> 1262 1263 <tr> 1264 <td>VP8</td> 1265 <td> </td> 1266 <td style="text-align: center;">REQUIRED<br/><small>(Android 2.3.3+)</small></td> 1267 <td> </td> 1268 <td><a href="http://www.webmproject.org/">WebM</a> (.webm) and Matroska (.mkv, Android 4.0+)</td> 1269 </tr> 1270 1271 </tbody></table> 1272 *Note: Only downmix of 5.0/5.1 content is required; recording or rendering more than 2 channels is optional. 1273 **Note: 16-bit linear PCM capture is mandatory. 8-bit linear PCM capture is not mandatory. 1274 1275 <a name="section-5.2"></a><h3>5.2 Video Encoding</h3> 1276 <p>Android device implementations that include a rear-facing camera and declare 1277 <code>android.hardware.camera</code> SHOULD support the following video encoding 1278 profiles.</p> 1279 <table> 1280 <thead> 1281 <tr> 1282 <th> </th> 1283 <th>SD (Low quality)</th> 1284 <th>SD (High quality)</th> 1285 <th>HD (When supported by hardware)</th> 1286 </tr> 1287 </thead> 1288 <tbody> 1289 <tr> 1290 <th>Video codec</th> 1291 <td>H.264 Baseline Profile</td> 1292 <td>H.264 Baseline Profile</td> 1293 <td>H.264 Baseline Profile</td> 1294 </tr> 1295 <tr> 1296 <th>Video resolution</th> 1297 <td>176 x 144 px</td> 1298 <td>480 x 360 px</td> 1299 <td>1280 x 720 px</td> 1300 </tr> 1301 <tr> 1302 <th>Video frame rate</th> 1303 <td>12 fps</td> 1304 <td>30 fps</td> 1305 <td>30 fps</td> 1306 </tr> 1307 <tr> 1308 <th>Video bitrate</th> 1309 <td>56 Kbps</td> 1310 <td>500 Kbps or higher</td> 1311 <td>2 Mbps or higher</td> 1312 </tr> 1313 <tr> 1314 <th>Audio codec</th> 1315 <td>AAC-LC</td> 1316 <td>AAC-LC</td> 1317 <td>AAC-LC</td> 1318 </tr> 1319 <tr> 1320 <th>Audio channels</th> 1321 <td>1 (mono)</td> 1322 <td>2 (stereo)</td> 1323 <td>2 (stereo)</td> 1324 </tr> 1325 <tr> 1326 <th>Audio bitrate</th> 1327 <td>24 Kbps</td> 1328 <td>128 Kbps</td> 1329 <td>192 Kbps</td> 1330 </tr> 1331 </tbody> 1332 </table> 1333 1334 <a name="section-5.3"></a><h3>5.3 Video Decoding</h3> 1335 <p>Android device implementations SHOULD support the following VP8 video decoding profiles.</p> 1336 <div style="page-break-before: always;"></div> 1337 <table> 1338 <thead> 1339 <tr> 1340 <th> </th> 1341 <th>SD (Low quality)</th> 1342 <th>SD (High quality)</th> 1343 <th>HD 720p <br/> (When supported by hardware)</th> 1344 <th>HD 1080p <br/>(When supported by hardware)</th> 1345 </tr> 1346 </thead> 1347 <tbody> 1348 <tr> 1349 <th>Video resolution</th> 1350 <td>320 x 180 px</td> 1351 <td>640 x 360 px</td> 1352 <td>1280 x 720 px</td> 1353 <td>1920 x 1080 px</td> 1354 </tr> 1355 <tr> 1356 <th>Video frame rate</th> 1357 <td>30 fps</td> 1358 <td>30 fps</td> 1359 <td>30 fps</td> 1360 <td>30 fps</td> 1361 </tr> 1362 <tr> 1363 <th>Video bitrate</th> 1364 <td>800 Kbps</td> 1365 <td>2 Mbps</td> 1366 <td>8 Mbps</td> 1367 <td>20 Mbps</td> 1368 </tr> 1369 </tbody> 1370 </table> 1371 <a name="section-5.4"></a><h3>5.4. Audio Recording</h3> 1372 <p>When an application has used the <code>android.media.AudioRecord</code> API to 1373 start recording an audio stream, device implementations that include microphone 1374 hardware and declare <code>android.hardware.microphone</code> MUST sample and 1375 record audio with each of these behaviors:</p> 1376 <ul> 1377 <li>The device SHOULD exhibit approximately flat amplitude versus frequency 1378 characteristics; specifically, ±3 dB, from 100 Hz to 4000 Hz</li> 1379 <li>Audio input sensitivity SHOULD be set such that a 90 dB sound power level 1380 (SPL) source at 1000 Hz yields RMS of 2500 for 16-bit samples.</li> 1381 <li>PCM amplitude levels SHOULD linearly track input SPL changes over at least 1382 a 30 dB range from -18 dB to +12 dB re 90 dB SPL at the microphone.</li> 1383 <li>Total harmonic distortion SHOULD be less than 1% for 1Khz at 90 dB SPL input level.</li> 1384 </ul> 1385 <p>In addition to the above recording specifications, when an application has 1386 started recording an audio stream using the 1387 <code>android.media.MediaRecorder.AudioSource.VOICE_RECOGNITION</code> audio 1388 source:</p> 1389 <ul> 1390 <li>Noise reduction processing, if present, MUST be disabled.</li> 1391 <li>Automatic gain control, if present, MUST be disabled.</li> 1392 </ul> 1393 <p><b>Note:</b> while some of the requirements outlined above are stated as "SHOULD" 1394 for Android 4.2, the Compatibility Definition for a future version is planned 1395 to change these to "MUST". That is, these requirements are optional in Android 1396 4.2 but <b>will be required</b> by a future version. Existing and new devices 1397 that run Android 4.2 are <b>very strongly encouraged to meet 1398 these requirements in Android 4.2</b>, or they will not be able to attain 1399 Android compatibility when upgraded to the future version.</p> 1400 1401 <a name="section-5.5"></a><h3>5.5. Audio Latency</h3> 1402 <p>Audio latency is the time delay as an audio signal passes through a system. 1403 Many classes of 1404 applications rely on short latencies, to achieve real-time effects such sound 1405 effects or VOIP communication.</p> 1406 <p>For the purposes of this section:</p> 1407 <ul> 1408 <li>"output latency" is defined as the interval between when an application 1409 writes a frame of PCM-coded data and when the corresponding sound can be heard 1410 by an external listener or observed by a transducer</li> 1411 <li>"cold output latency" is defined as the output latency for the first frame, when 1412 the audio output system has been idle and powered down prior to the request</li> 1413 <li>"continuous output latency" is defined as the output latency for subsequent frames, 1414 after the device is already playing audio</li> 1415 <li>"input latency" is the interval between when an external sound is presented 1416 to the device and when an application reads the corresponding frame of PCM-coded data</li> 1417 <li>"cold input latency" is defined as the sum of lost input time 1418 and the input latency for the first frame, when 1419 the audio input system has been idle and powered down prior to the request</li> 1420 <li>"continuous input latency" is defined as the input latency for subsequent frames, 1421 while the device is already capturing audio</li> 1422 <li>"OpenSL ES PCM buffer queue API" is the set of PCM-related OpenSL ES APIs within Android NDK; 1423 see <i>NDK_root</i><code>/docs/opensles/index.html</code></li> 1424 </ul> 1425 <p>Per <a href="#section-5">Section 5</a>, 1426 all compatible device implementations MUST include at least one form of audio output. 1427 Device implementations SHOULD meet or exceed these output latency requirements:</p> 1428 <ul> 1429 <li>cold output latency of 100 milliseconds or less</li> 1430 <li>continuous output latency of 45 milliseconds or less</li> 1431 </ul> 1432 <p>If a device implementation meets the requirements of this section 1433 after any initial calibration 1434 when using the OpenSL ES PCM buffer queue API, 1435 for continuous output latency and cold output latency 1436 over at least one supported audio output device, it MAY 1437 report support for low-latency audio, by reporting the feature 1438 "android.hardware.audio.low-latency" via the 1439 <code>android.content.pm.PackageManager</code> class. [<a 1440 href="#resources37">Resources, 37</a>] Conversely, if the device 1441 implementation does not meet these requirements it MUST NOT report support for 1442 low-latency audio.</p> 1443 <p> 1444 Per <a href="#section-7.2.5">Section 7.2.5</a>, 1445 microphone hardware may be omitted by device implementations.</p> 1446 <p> 1447 Device implementations that include microphone 1448 hardware and declare <code>android.hardware.microphone</code> SHOULD 1449 meet these input audio latency requirements:</p> 1450 <ul> 1451 <li>cold input latency of 100 milliseconds or less</li> 1452 <li>continuous input latency of 50 milliseconds or less</li> 1453 </ul> 1454 1455 <a name="section-5.6"></a><h3>5.6. Network Protocols</h3> 1456 <p>Devices MUST support the media network protocols for audio and video playback 1457 as specified in the Android SDK documentation 1458 [<a href="#resources58">Resources, 58</a>]. Specifically, devices MUST support 1459 the following media network protocols:</p> 1460 <ul> 1461 <li>RTSP (RTP, SDP)</li> 1462 <li>HTTP(S) progressive streaming</li> 1463 <li>HTTP(S) Live Streaming draft protocol, Version 3 [<a href="#resources59">Resources, 59</a>]</li> 1464 </ul> 1465 <a name="section-6"></a><h2>6. Developer Tools and Options Compatibility</h2> 1466 1467 <a name="section-6.1"></a><h3>6.1 Developer Tools</h3> 1468 <p>Device implementations MUST support the Android Developer Tools provided in the Android SDK. 1469 Specifically, Android-compatible devices MUST be compatible with:</p> 1470 <ul> 1471 <li><b>Android Debug Bridge (known as adb)</b> [<a href="#resources33">Resources, 33</a>]<br/> 1472 Device implementations MUST support all <code>adb</code> functions as 1473 documented in the Android SDK. The device-side <code>adb</code> daemon MUST 1474 be inactive by default, and there MUST be a user-accessible mechanism to turn 1475 on the Android Debug Bridge.</li> 1476 <p>Android 4.2.2 includes support for secure adb. Secure adb enables adb on known authenticated hosts. 1477 Existing and new devices that run Android 4.2.2 are <b>very strongly encouraged to meet 1478 this requirement in Android 4.2</b>, or they will not be able to attain 1479 Android compatibility when upgraded to the future version.</p> 1480 <li><b>Dalvik Debug Monitor Service (known as ddms)</b> [<a href="#resources33">Resources, 33</a>]<br/> 1481 Device implementations MUST support all <code>ddms</code> features as documented in the 1482 Android SDK. As <code>ddms</code> uses <code>adb</code>, support for 1483 <code>ddms</code> SHOULD be inactive by default, 1484 but MUST be supported whenever the user has activated the Android Debug 1485 Bridge, as above.</li> 1486 <li><b>Monkey</b> [<a href="#resources36">Resources, 36</a>]<br/> 1487 Device implementations MUST include the Monkey framework, and make it 1488 available for applications to use.</li> 1489 <li><b>SysTrace</b> [<a href="#resources33">Resources, 33</a>]<br/> 1490 Device implementations MUST support systrace tool as documented in the Android SDK. 1491 Systrace must be inactive by default, and there MUST be a user-accessible mechanism to turn 1492 on Systrace.</li> 1493 </ul> 1494 <p>Most Linux-based systems and Apple Macintosh systems recognize Android 1495 devices using the standard Android SDK tools, without additional support; 1496 however Microsoft Windows systems typically require a driver for new Android 1497 devices. (For instance, new vendor IDs and sometimes new device IDs require 1498 custom USB drivers for Windows systems.) If a device implementation is 1499 unrecognized by the <code>adb</code> tool as provided in the standard Android 1500 SDK, device implementers MUST provide Windows drivers allowing developers to 1501 connect to the device using the <code>adb</code> protocol. These drivers MUST 1502 be provided for Windows XP, Windows Vista, Windows 7, and Windows 8, in both 32-bit and 1503 64-bit versions.</p> 1504 1505 <a name="section-6.2"></a><h3>6.2 Developer Options</h3> 1506 <p>Android 4.2 includes support for developers to configure application development-related settings. 1507 Device implementations MUST honor the android.settings.APPLICATION_DEVELOPMENT_SETTINGS intent to show 1508 application development-related settings [<a href="#resources77">Resources, 77</a>]. The upstream Android 1509 implementation hides the Developer Options menu by default, and enables users to launch Developer Options 1510 after pressing seven (7) times on the Settings > About Device > Build Number menu item. Device implementations 1511 MUST provide a consistent experience for Developer Options. Specifically, device implementations MUST hide 1512 Developer Options by default and MUST provide a mechanism to enable Developer Options that is consistent with 1513 the upstream Android implementation.</p> 1514 1515 <a name="section-7"></a><h2>7. Hardware Compatibility</h2> 1516 <p>If a device includes a particular hardware component that has a 1517 corresponding API for third-party developers, the device implementation MUST 1518 implement that API as described in the Android SDK documentation. If an API in 1519 the SDK interacts with a hardware component that is stated to be optional and 1520 the device implementation does not possess that component:</p> 1521 <ul> 1522 <li>complete class definitions (as documented by the SDK) for the component's 1523 APIs MUST still be present</li> 1524 <li>the API's behaviors MUST be implemented as no-ops in some reasonable 1525 fashion</li> 1526 <li>API methods MUST return null values where permitted by the SDK 1527 documentation</li> 1528 <li>API methods MUST return no-op implementations of classes where null 1529 values are not permitted by the SDK documentation</li> 1530 <li>API methods MUST NOT throw exceptions not documented by the SDK 1531 documentation</li> 1532 </ul> 1533 <p>A typical example of a scenario where these requirements apply is the 1534 telephony API: even on non-phone devices, these APIs must be implemented as 1535 reasonable no-ops.</p> 1536 <p>Device implementations MUST accurately report accurate hardware configuration 1537 information via the <code>getSystemAvailableFeatures()</code> and 1538 <code>hasSystemFeature(String)</code> methods on the 1539 <code>android.content.pm.PackageManager</code> class. [<a 1540 href="#resources37">Resources, 37</a>]</p> 1541 1542 <a name="section-7.1"></a><h3>7.1. Display and Graphics</h3> 1543 <p>Android 4.2 includes facilities that automatically adjust application 1544 assets and UI layouts appropriately for the device, to ensure that third-party 1545 applications run well on a variety of hardware configurations [<a 1546 href="#resources38">Resources, 38</a>]. Devices MUST properly implement these 1547 APIs and behaviors, as detailed in this section.</p> 1548 1549 <p>The units referenced by the requirements in this section are defined as follows:</p> 1550 <ul> 1551 <li>"Physical diagonal size" is the distance in inches between two opposing 1552 corners of the illuminated portion of the display.</li> 1553 <li>"dpi" (meaning "dots per inch") is the number of pixels encompassed by a 1554 linear horizontal or vertical span of 1". Where dpi values are listed, both 1555 horizontal and vertical dpi must fall within the range.</li> 1556 <li>"Aspect ratio" is the ratio of the longer dimension of the screen to the 1557 shorter dimension. For example, a display of 480x854 pixels would be 854 / 480 1558 = 1.779, or roughly "16:9".</li> 1559 <li>A "density-independent pixel" or ("dp") is the virtual pixel unit normalized to a 1560 160 dpi screen, calculated as: 1561 <code>pixels = dps * (density / 160)</code>.</li> 1562 </ul> 1563 1564 1565 <a name="section-7.1.1"></a><h4>7.1.1. Screen Configuration</h4> 1566 1567 <p style="font-weight:bold;">Screen Size</p> 1568 <p>The Android UI framework supports a variety of different screen sizes, and 1569 allows applications to query the device screen size (aka "screen layout") via 1570 <code>android.content.res.Configuration.screenLayout</code> with the 1571 <code>SCREENLAYOUT_SIZE_MASK</code>. Device implementations MUST report the 1572 correct screen size as defined in the Android SDK documentation 1573 [<a href="#resources38">Resources, 38</a>] and determined by the upstream 1574 Android platform. Specifically, device implementations must report the correct 1575 screen size according to the following logical density-independent pixel (dp) 1576 screen dimensions.</p> 1577 <ul> 1578 <li>Devices MUST have screen sizes of at least 426 dp x 320 dp ('small')</li> 1579 <li>Devices that report screen size 'normal' MUST have screen sizes of at least 1580 480 dp x 320 dp</li> 1581 <li>Devices that report screen size 'large' MUST have screen sizes of at least 1582 640 dp x 480 dp</li> 1583 <li>Devices that report screen size 'xlarge' MUST have screen sizes of at least 1584 960 dp x 720 dp</li> 1585 </ul> 1586 <p>In addition, devices MUST have screen sizes of at least 2.5 inches in 1587 physical diagonal size.</p> 1588 1589 <p>Devices MUST NOT change their reported screen size at any time.</p> 1590 <p>Applications optionally indicate which screen sizes they support via the 1591 <code><supports-screens></code> attribute in the AndroidManifest.xml 1592 file. Device implementations MUST correctly honor applications' stated support 1593 for small, normal, large, and xlarge screens, as described in the Android 1594 SDK documentation.</p> 1595 1596 <p style="font-weight:bold;">Screen Aspect Ratio</p> 1597 <p>The aspect ratio MUST be between 1.3333 (4:3) and 1.85 (16:9).</p> 1598 1599 <p style="font-weight:bold;">Screen Density</p> 1600 <p>The Android UI framework defines a set of standard logical densities to 1601 help application developers target application resources. Device 1602 implementations MUST report one of the following logical Android framework 1603 densities through the <code>android.util.DisplayMetrics</code> APIs, and MUST 1604 execute applications at this standard density. 1605 <ul> 1606 <li>120 dpi, known as 'ldpi'</li> 1607 <li>160 dpi, known as 'mdpi'</li> 1608 <li>213 dpi, known as 'tvdpi'</li> 1609 <li>240 dpi, known as 'hdpi'</li> 1610 <li>320 dpi, known as 'xhdpi'</li> 1611 <li>480 dpi, known as 'xxhdpi'</li> 1612 </ul> 1613 Device implementations SHOULD define the standard Android framework density 1614 that is numerically closest to the physical density of the screen, unless that 1615 logical density pushes the reported screen size below the minimum supported. 1616 If the standard Android framework density that is numerically closest to the 1617 physical density results in a screen size that is smaller than the smallest 1618 supported compatible screen size (320 dp width), device implementations SHOULD 1619 report the next lowest standard Android framework density.</p> 1620 1621 <a name="section-7.1.2"></a><h4>7.1.2. Display Metrics</h4> 1622 <p>Device implementations MUST report correct values for all display metrics 1623 defined in <code>android.util.DisplayMetrics</code> [<a 1624 href="#resources39">Resources, 39</a>].</p> 1625 1626 <a name="section-7.1.3"></a><h4>7.1.3. Screen Orientation</h4> 1627 <p>Devices MUST support dynamic orientation by applications to 1628 either portrait or landscape screen orientation. That is, the device must 1629 respect the application's request for a specific screen orientation. Device 1630 implementations MAY select either portrait or landscape orientation as the 1631 default.</p> 1632 <p>Devices MUST report the correct value for the device's current orientation, 1633 whenever queried via the android.content.res.Configuration.orientation, 1634 android.view.Display.getOrientation(), or other APIs.</p> 1635 <p>Devices MUST NOT change the reported screen size or density when changing 1636 orientation.</p> 1637 <p>Devices MUST report which screen orientations they support ( 1638 <code>android.hardware.screen.portrait</code> and/or 1639 <code>android.hardware.screen.landscape</code>) and MUST report at least one 1640 supported orientation. For example, a device with a fixed-orientation 1641 landscape screen, such as a television or laptop, MUST only report 1642 <code>android.hardware.screen.landscape</code>.</p> 1643 1644 <a name="section-7.1.4"></a><h4>7.1.4. 2D and 3D Graphics Acceleration</h4> 1645 <p>Device implementations MUST support both OpenGL ES 1.0 and 2.0, as embodied 1646 and detailed in the Android SDK documentations. Device implementations MUST 1647 also support Android Renderscript, as detailed in the Android SDK 1648 documentation [<a href="#resources08">Resources, 8</a>].</p> 1649 <p>Device implementations MUST also correctly identify themselves as 1650 supporting OpenGL ES 1.0 and 2.0. That is:</p> 1651 <ul> 1652 <li>The managed APIs (such as via the <code>GLES10.getString()</code> method) 1653 MUST report support for OpenGL ES 1.0 and 2.0</li> 1654 <li>The native C/C++ OpenGL APIs (that is, those available to apps via 1655 libGLES_v1CM.so, libGLES_v2.so, or libEGL.so) MUST report support for 1656 OpenGL ES 1.0 and 2.0.</li> 1657 </ul> 1658 <p>Device implementations MAY implement any desired OpenGL ES extensions. 1659 However, device implementations MUST report via the OpenGL ES managed and 1660 native APIs all extension strings that they do support, and conversely MUST 1661 NOT report extension strings that they do not support.</p> 1662 <p>Note that Android 4.2 includes support for applications to optionally 1663 specify that they require specific OpenGL texture compression formats. These 1664 formats are typically vendor-specific. Device implementations are not required 1665 by Android 4.2 to implement any specific texture compression format. However, 1666 they SHOULD accurately report any texture compression formats that they do 1667 support, via the <code>getString()</code> method in the OpenGL API.</p> 1668 1669 <p>Android 4.2 includes a mechanism for applications to declare that they 1670 wanted to enable hardware acceleration for 2D graphics at the Application, 1671 Activity, Window or View level through the use of a manifest tag 1672 <code>android:hardwareAccelerated</code> or direct API calls 1673 [<a href="#resources09">Resources, 9</a>].</p> 1674 <p>In Android 4.2, device implementations MUST enable hardware acceleration by 1675 default, and MUST disable hardware acceleration if the developer so requests 1676 by setting <code>android:hardwareAccelerated="false"</code> or disabling 1677 hardware acceleration directly through the Android View APIs.</p> 1678 <p>In addition, device implementations MUST exhibit behavior consistent with the 1679 Android SDK documentation on hardware acceleration 1680 [<a href="#resources09">Resources, 9</a>].</p> 1681 <p>Android 4.2 includes a <code>TextureView</code> object that lets developers 1682 directly integrate hardware-accelerated OpenGL ES textures as rendering targets 1683 in a UI hierarchy. Device implementations MUST support the <code>TextureView 1684 </code> API, and MUST exhibit consistent behavior with the upstream Android 1685 implementation.</p> 1686 1687 <a name="section-7.1.5"></a><h4>7.1.5. Legacy Application Compatibility Mode</h4> 1688 <p>Android 4.2 specifies a "compatibility mode" in which the framework 1689 operates in an 'normal' screen size equivalent (320dp width) mode for the benefit 1690 of legacy applications not developed for old versions of Android that pre-date 1691 screen-size independence. Device implementations MUST include support for legacy 1692 application compatibility mode as implemented by the upstream Android open source 1693 code. That is, device implementations MUST NOT alter the triggers or thresholds at 1694 which compatibility mode is activated, and MUST NOT alter the behavior of the 1695 compatibility mode itself.</p> 1696 1697 <a name="section-7.1.6"></a><h4>7.1.6. Screen Types</h4> 1698 <p>Device implementation screens are classified as one of two types:</p> 1699 <ul> 1700 <li>Fixed-pixel display implementations: the screen is a single panel that supports only a 1701 single pixel width and height. Typically the screen is physically integrated with 1702 the device. Examples include mobile phones, tablets, and so on.</li> 1703 <li>Variable-pixel display implementations: the device implementation either has no 1704 embedded screen and includes a video output port such as VGA, HDMI or a wireless port 1705 for display, or has an embedded screen that can change pixel dimensions. Examples 1706 include televisions, set-top boxes, and so on.</li> 1707 </ul> 1708 <p style="font-weight: bold;">Fixed-Pixel Device Implementations</p> 1709 <p>Fixed-pixel device implementations MAY use screens of any pixel dimensions, provided 1710 that they meet the requirements defined this Compatibility Definition.</p> 1711 <p>Fixed-pixel implementations MAY include a video output port for use with an 1712 external display. However, if that display is ever used for running apps, the 1713 device MUST meet the following requirements:</p> 1714 <ul> 1715 <li>The device MUST report the same screen configuration and display metrics, as detailed 1716 in Sections 7.1.1 and 7.1.2, as the fixed-pixel display.</li> 1717 <li>The device MUST report the same logical density as the fixed-pixel display.</li> 1718 <li>The device MUST report screen dimensions that are the same as, or very close to, 1719 the fixed-pixel display.</li> 1720 </ul> 1721 <p>For example, a tablet that is 7" diagonal size with a 1024x600 pixel resolution is 1722 considered a fixed-pixel large mdpi display implementation. If it contains a video 1723 output port that displays at 720p or 1080p, the device implementation MUST scale the output so that 1724 applications are only executed in a large mdpi window, regardless of whether the fixed-pixel display 1725 or video output port is in use.</p> 1726 1727 <p style="font-weight: bold;">Variable-Pixel Device Implementations</p> 1728 <p>Variable-pixel device implementations MUST support one or both of 1280x720, 1729 or 1920x1080 (that is, 720p or 1080p). Device implementations with 1730 variable-pixel displays MUST NOT support any other screen configuration or 1731 mode. Device implementations with variable-pixel screens MAY change screen 1732 configuration or mode at runtime or boot-time. For example, a user of a 1733 set-top box may replace a 720p display with a 1080p display, and the device 1734 implementation may adjust accordingly.</p> 1735 1736 <p>Additionally, variable-pixel device implementations MUST report the following 1737 configuration buckets for these pixel dimensions:</p> 1738 <ul> 1739 <li>1280x720 (also known as 720p): 'large' screen size, 'tvdpi' (213 dpi) 1740 density</li> 1741 <li>1920x1080 (also known as 1080p): 'large' screen size, 'xhdpi' (320 dpi) 1742 density</li> 1743 </ul> 1744 <p>For clarity, device implementations with variable pixel dimensions are 1745 restricted to 720p or 1080p in Android 4.2, and MUST be configured to report 1746 screen size and density buckets as noted above.</p> 1747 1748 <a name="section-7.1.7"></a><h4>7.1.7. Screen Technology</h4> 1749 <p>The Android platform includes APIs that allow applications to render rich 1750 graphics to the display. Devices MUST support all of these APIs as defined by 1751 the Android SDK unless specifically allowed in this document. Specifically:</p> 1752 <ul> 1753 <li>Devices MUST support displays capable of rendering 16-bit color graphics and 1754 SHOULD support displays capable of 24-bit color graphics.</li> 1755 <li>Devices MUST support displays capable of rendering animations.</li> 1756 <li>The display technology used MUST have a pixel aspect ratio (PAR) between 1757 0.9 and 1.1. That is, the pixel aspect ratio MUST be near square (1.0) with 1758 a 10% tolerance.</li> 1759 </ul> 1760 <a name="section-7.1.8"></a><h4>7.1.8. External Displays</h4> 1761 <p>Android 4.2 includes support for secondary display to enable media sharing capabilities and 1762 developer APIs for accessing external displays. If a device supports an external display either via 1763 a wired, wireless or an embedded additional display connection then the device implementation MUST 1764 implement the display manager API as described in the Android SDK documentation [<a href="#resources75">Resources, 75</a>]. 1765 Device implementations that support secure video output and are capable of supporting secure surfaces MUST declare support 1766 for <code>Display.SECURE_FLAG</code>. Specifically, device implementations that declare support for <code>Display.SECURE_FLAG</code>, 1767 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 1768 Android open source implementation includes support for wireless (Miracast) and wired (HDMI) displays that satisfies this requirement.</p> 1769 1770 <a name="section-7.2"></a><h3>7.2. Input Devices</h3> 1771 <a name="section-7.2.1"></a><h4>7.2.1. Keyboard</h4> 1772 <p>Device implementations:</p> 1773 <ul> 1774 <li>MUST include support for the Input Management Framework (which allows third 1775 party developers to create Input Management Engines - i.e. soft keyboard) as 1776 detailed at <a href="http://developer.android.com">http://developer.android.com</a> 1777 </li> 1778 <li>MUST provide at least one soft keyboard implementation (regardless of whether 1779 a hard keyboard is present)</li> 1780 <li>MAY include additional soft keyboard implementations</li> 1781 <li>MAY include a hardware keyboard</li> 1782 <li>MUST NOT include a hardware keyboard that does not match one of the 1783 formats specified in <code>android.content.res.Configuration.keyboard</code> 1784 [<a href="#resources40">Resources, 40</a>] (that is, QWERTY, or 12-key)</li> 1785 </ul> 1786 <a name="section-7.2.2"></a><h4>7.2.2. Non-touch Navigation</h4> 1787 <p>Device implementations:</p> 1788 <ul> 1789 <li>MAY omit a non-touch navigation option (that is, may omit a trackball, d-pad, 1790 or wheel)</li> 1791 <li>MUST report the correct value for 1792 <code>android.content.res.Configuration.navigation</code> 1793 [<a href="#resources40">Resources, 40</a>]</li> 1794 <li>MUST provide a reasonable alternative user interface mechanism for the 1795 selection and editing of text, compatible with Input Management Engines. The 1796 upstream Android open source implementation includes a selection mechanism suitable 1797 for use with devices that lack non-touch navigation inputs.</li> 1798 </ul> 1799 <a name="section-7.2.3"></a><h4>7.2.3. Navigation keys</h4> 1800 <p>The Home, Menu and Back functions are essential to the Android navigation 1801 paradigm. Device implementations MUST make these functions available to the 1802 user at all times when running applications. These functions MAY be implemented 1803 via dedicated physical buttons (such as mechanical or capacitive touch buttons), 1804 or MAY be implemented using dedicated software keys, gestures, touch panel, etc. 1805 Android 4.2 supports both implementations.</p> 1806 1807 <p>Android 4.2 includes support for assist action [<a href="#resources63">Resources, 63</a>]. 1808 Device implementations MUST make the assist action available to the user at all times when running applications. 1809 This function MAY be implemented via hardware or software keys.</p> 1810 1811 <p>Device implementations MAY use a distinct portion of the screen to display 1812 the navigation keys, but if so, MUST meet these requirements:</p> 1813 1814 <ul> 1815 <li>Device implementation navigation keys MUST use a distinct portion of the 1816 screen, not available to applications, and MUST NOT obscure or otherwise 1817 interfere with the portion of the screen available to applications.</li> 1818 <li>Device implementations MUST make available a portion of the display to 1819 applications that meets the requirements defined in 1820 <a href="section-7.1.1">Section 7.1.1</a>.</li> 1821 <li>Device implementations MUST display the navigation keys when applications 1822 do not specify a system UI mode, or specify 1823 <code>SYSTEM_UI_FLAG_VISIBLE</code>.</li> 1824 <li>Device implementations MUST present the navigation keys in an unobtrusive 1825 "low profile" (eg. dimmed) mode when applications specify 1826 <code>SYSTEM_UI_FLAG_LOW_PROFILE</code>.</li> 1827 <li>Device implementations MUST hide the navigation keys when applications 1828 specify <code>SYSTEM_UI_FLAG_HIDE_NAVIGATION</code>.</li> 1829 <li>Device implementation MUST present a Menu key to applications when 1830 targetSdkVersion <= 10 and SHOULD NOT present a Menu key when the 1831 targetSdkVersion > 10.</li> 1832 </ul> 1833 1834 <a name="section-7.2.4"></a><h4>7.2.4. Touchscreen input</h4> 1835 <p>Device implementations:</p> 1836 <ul> 1837 <li>MUST have a pointer input system of some kind (either mouse-like, or 1838 touch)</li> 1839 <li>MAY have a touchscreen of any modality (such as capacitive or resistive)</li> 1840 <li>SHOULD support fully independently tracked pointers, if a touchscreen 1841 supports multiple pointers</li> 1842 <li>MUST report the value of <code>android.content.res.Configuration</code> 1843 [<a href="#resources40">Resources, 39</a>] 1844 reflecting corresponding to the type of the specific touchscreen on the 1845 device</li> 1846 </ul> 1847 <p>Device implementations MUST report the correct feature corresponding to the 1848 type of input used. Note that Android 4.2 includes the feature 1849 <code>android.hardware.faketouch</code>, which corresponds to a high-fidelity 1850 non-touch (that is, pointer-based) input device such as a mouse or trackpad that 1851 can adequately emulate touch-based input (including basic gesture support), 1852 and indicates that the device supports an emulated subset of touchscreen 1853 functionality. 1854 Device implementations that include a touchscreen (single-touch or better) 1855 MUST also report android.hardware.faketouch. Device implementations that do 1856 not include a touchscreen (and rely on a pointer device only) MUST NOT report 1857 any touchscreen feature, and MUST report only 1858 <code>android.hardware.faketouch</code>.</p> 1859 <a name="section-7.2.5"></a><h4>7.2.5. Microphone</h4> 1860 <p>Device implementations MAY omit a microphone. However, if a device 1861 implementation omits a microphone, it MUST NOT report the 1862 <code>android.hardware.microphone</code> feature constant, and must implement 1863 the audio recording API as no-ops, per <a href="section-7">Section 7</a>. 1864 Conversely, device implementations that do possess a microphone:</p> 1865 <ul> 1866 <li>MUST report the <code>android.hardware.microphone</code> feature constant</li> 1867 <li>SHOULD meet the audio quality requirements in <a href="section-5.4">Section 5.4</a></li> 1868 <li>SHOULD meet the audio latency requirements in <a href="section-5.5">Section 5.5</a></li> 1869 </ul> 1870 1871 <a name="section-7.3"></a><h3>7.3. Sensors</h3> 1872 <p>Android 4.2 includes APIs for accessing a variety of sensor types. Devices 1873 implementations generally MAY omit these sensors, as provided for in the 1874 following subsections. If a device includes a particular sensor type that has a 1875 corresponding API for third-party developers, the device implementation MUST 1876 implement that API as described in the Android SDK documentation. For example, 1877 device implementations:</p> 1878 <ul> 1879 <li>MUST accurately report the presence or absence of sensors per the 1880 <code>android.content.pm.PackageManager</code> class. [<a 1881 href="#resources37">Resources, 37</a>]</li> 1882 <li>MUST return an accurate list of supported sensors via the 1883 <code>SensorManager.getSensorList()</code> and similar methods</li> 1884 <li>MUST behave reasonably for all other sensor APIs (for example, by 1885 returning true or false as appropriate when applications attempt to register 1886 listeners, not calling sensor listeners when the corresponding sensors are not 1887 present; etc.)</li> 1888 <li>MUST report all sensor measurements using the relevant International System 1889 of Units (i.e. metric) values for each sensor type as defined in the Android SDK 1890 documentation [<a href="#resources41">Resources, 41</a>]</li> 1891 </ul> 1892 <p>The list above is not comprehensive; the documented behavior of the Android 1893 SDK is to be considered authoritative.</p> 1894 <p>Some sensor types are synthetic, meaning they can be derived from data 1895 provided by one or more other sensors. (Examples include the orientation 1896 sensor, and the linear acceleration sensor.) Device implementations SHOULD 1897 implement these sensor types, when they include the prerequisite physical 1898 sensors.</p> 1899 <p>The Android 4.2 includes a notion of a "streaming" sensor, which is 1900 one that returns data continuously, rather than only when the data changes. 1901 Device implementations MUST continuously provide periodic data samples for any 1902 API indicated by the Android 4.2 SDK documentation to be a streaming 1903 sensor. Note that the device implementations MUST ensure that the sensor stream must not 1904 prevent the device CPU from entering a suspend state or waking up from a suspend state.</p> 1905 1906 <a name="section-7.3.1"></a><h4>7.3.1. Accelerometer</h4> 1907 <p>Device implementations SHOULD include a 3-axis accelerometer. If a device 1908 implementation does include a 3-axis accelerometer, it:</p> 1909 <ul> 1910 <li>SHOULD be able to deliver events at 120 Hz or greater. Note that while the 1911 accelerometer frequency above is stated as "SHOULD" for Android 4.2, the Compatibility Definition 1912 for a future version is planned to change these to "MUST". That is, these standards are 1913 optional in Android 4.2 but <b>will be required</b> in future versions. Existing and 1914 new devices that run Android 4.2 are <b>very strongly encouraged to meet these requirements 1915 in Android 4.2</b> so they will be able to upgrade to the future platform releases 1916 </li> 1917 <li>MUST comply with the Android sensor coordinate system as detailed 1918 in the Android APIs (see [<a href="#resources41">Resources, 41</a>])</li> 1919 <li>MUST be capable of measuring from freefall up to twice gravity (2g) or 1920 more on any three-dimensional vector</li> 1921 <li>MUST have 8-bits of accuracy or more</li> 1922 <li>MUST have a standard deviation no greater than 0.05 m/s^2</li> 1923 </ul> 1924 <a name="section-7.3.2"></a><h4>7.3.2. Magnetometer</h4> 1925 <p>Device implementations SHOULD include a 3-axis magnetometer (i.e. compass.) 1926 If a device does include a 3-axis magnetometer, it:</p> 1927 <ul> 1928 <li>MUST be able to deliver events at 10 Hz or greater</li> 1929 <li>MUST comply with the Android sensor coordinate system as detailed 1930 in the Android APIs (see [<a href="#resources41">Resources, 41</a>]).</li> 1931 <li>MUST be capable of sampling a range of field strengths adequate to cover the 1932 geomagnetic field</li> 1933 <li>MUST have 8-bits of accuracy or more</li> 1934 <li>MUST have a standard deviation no greater than 0.5 µT</li> 1935 </ul> 1936 <a name="section-7.3.3"></a><h4>7.3.3. GPS</h4> 1937 <p>Device implementations SHOULD include a GPS receiver. If a device 1938 implementation does include a GPS receiver, it SHOULD include 1939 some form of "assisted GPS" technique to minimize GPS lock-on time.</p> 1940 <a name="section-7.3.4"></a><h4>7.3.4. Gyroscope</h4> 1941 <p>Device implementations SHOULD include a gyroscope (i.e. angular change 1942 sensor.) Devices SHOULD NOT include a gyroscope sensor unless a 3-axis 1943 accelerometer is also included. If a device implementation includes a 1944 gyroscope, it:</p> 1945 <ul> 1946 <li>MUST be temperature compensated</li> 1947 <li>MUST be capable of measuring orientation changes up to 5.5*Pi 1948 radians/second (that is, approximately 1,000 degrees per second)</li> 1949 <li>SHOULD be able to deliver events at 200 Hz or greater. Note that while the 1950 gyroscope frequency above is stated as "SHOULD" for Android 4.2, the Compatibility Definition 1951 for a future version is planned to change these to "MUST". That is, these standards are 1952 optional in Android 4.2 but <b>will be required</b> in future versions. Existing and 1953 new devices that run Android 4.2 are <b>very strongly encouraged to meet these requirements 1954 in Android 4.2</b> so they will be able to upgrade to the future platform releases 1955 </li> 1956 <li>MUST have 12-bits of accuracy or more</li> 1957 <li>MUST have a variance no greater than 1e-7 rad^2 / s^2 per Hz (variance per Hz, or rad^2 / s). 1958 The variance is allowed to vary with the sampling rate, but must be constrained by this value. 1959 In other words, if you measure the variance of the gyro at 1 Hz sampling rate it should be no 1960 greater than 1e-7 rad^2/s^2. </li> 1961 <li>MUST have timestamps as close to when the hardware event happened as possible. The constant latency must be removed.</li> 1962 </ul> 1963 <a name="section-7.3.5"></a><h4>7.3.5. Barometer</h4> 1964 <p>Device implementations MAY include a barometer (i.e. ambient air pressure 1965 sensor.) If a device implementation includes a barometer, it:</p> 1966 <ul> 1967 <li>MUST be able to deliver events at 5 Hz or greater</li> 1968 <li>MUST have adequate precision to enable estimating altitude</li> 1969 <li>MUST be temperature compensated</li> 1970 </ul> 1971 <a name="section-7.3.6"></a><h4>7.3.7. Thermometer</h4> 1972 <p>Device implementations MAY but SHOULD NOT include a thermometer (i.e. 1973 temperature sensor.) If a device implementation does include a thermometer, it 1974 MUST measure the temperature of the device CPU. It MUST NOT measure any other 1975 temperature. (Note that this sensor type is deprecated in the Android 4.2 1976 APIs.)</p> 1977 <a name="section-7.3.7"></a><h4>7.3.7. Photometer</h4> 1978 <p>Device implementations MAY include a photometer (i.e. ambient light 1979 sensor.)</p> 1980 <a name="section-7.3.8"></a><h4>7.3.8. Proximity Sensor</h4> 1981 <p>Device implementations MAY include a proximity sensor. If a device 1982 implementation does include a proximity sensor, it MUST measure the proximity 1983 of an object in the same direction as the screen. That is, the proximity 1984 sensor MUST be oriented to detect objects close to the screen, as the 1985 primary intent of this sensor type is to detect a phone in use by the 1986 user. If a device implementation includes a proximity sensor with any other 1987 orientation, it MUST NOT be accessible through this API. If a device 1988 implementation has a proximity sensor, it MUST be have 1-bit of accuracy or 1989 more.</p> 1990 1991 <a name="section-7.4"></a><h3>7.4. Data Connectivity</h3> 1992 <a name="section-7.4.1"></a><h4>7.4.1. Telephony</h4> 1993 <p>"Telephony" as used by the Android 4.2 APIs and this document refers 1994 specifically to hardware related to placing voice calls and sending SMS 1995 messages via a GSM or CDMA network. While these voice calls may or may not be 1996 packet-switched, they are for the purposes of Android 4.2 considered 1997 independent of any data connectivity that may be implemented using the same 1998 network. In other words, the Android "telephony" functionality and APIs refer 1999 specifically to voice calls and SMS; for instance, device implementations that 2000 cannot place calls or send/receive SMS messages MUST NOT report the 2001 "android.hardware.telephony" feature or any sub-features, regardless of 2002 whether they use a cellular network for data connectivity.</p> 2003 <p>Android 4.2 MAY be used on devices that do not include telephony hardware. 2004 That is, Android 4.2 is compatible with devices that are not phones. 2005 However, if a device implementation does include GSM or CDMA telephony, it 2006 MUST implement full support for the API for that technology. Device 2007 implementations that do not include telephony hardware MUST implement the full 2008 APIs as no-ops.</p> 2009 <a name="section-7.4.2"></a><h4>7.4.2. IEEE 802.11 (WiFi)</h4> 2010 <p>Android 4.2 device implementations SHOULD include support for one or more 2011 forms of 802.11 (b/g/a/n, etc.) If a device implementation does include 2012 support for 802.11, it MUST implement the corresponding Android API.</p> 2013 <p>Device implementations MUST implement the multicast API as described in 2014 the SDK documentation [<a href="#resources62">Resources, 62</a>]. Device 2015 implementations that do include Wifi support MUST support multicast DNS (mDNS). 2016 Device implementations MUST not filter mDNS packets (224.0.0.251) at any time 2017 of operation including when the screen is not in an active state.</p> 2018 2019 <a name="section-7.4.2.1"></a><h4>7.4.2.1. WiFi Direct</h4> 2020 <p>Device implementations SHOULD include support for Wifi direct (Wifi peer-to-peer). 2021 If a device implementation does include support for Wifi direct, it MUST implement the corresponding 2022 Android API as described in the SDK documentation [<a href="#resources68">Resources, 68</a>]. 2023 If a device implementation includes support for Wifi direct, then it:</p> 2024 <ul> 2025 <li>MUST support regular Wifi operation</li> 2026 <li>SHOULD support concurrent wifi and wifi Direct operation</li> 2027 </ul> 2028 2029 <a name="section-7.4.3"></a><h4>7.4.3. Bluetooth</h4> 2030 <p>Device implementations SHOULD include a Bluetooth transceiver. Device 2031 implementations that do include a Bluetooth transceiver MUST enable the 2032 RFCOMM-based Bluetooth API as described in the SDK documentation [<a 2033 href="#resources42">Resources, 42</a>]. Device implementations SHOULD 2034 implement relevant Bluetooth profiles, such as A2DP, AVRCP, OBEX, etc. as 2035 appropriate for the device.</p> 2036 <p>The Compatibility Test Suite includes cases that cover basic operation of 2037 the Android RFCOMM Bluetooth API. However, since Bluetooth is a communications 2038 protocol between devices, it cannot be fully tested by unit tests running on a 2039 single device. Consequently, device implementations MUST also pass the 2040 human-driven Bluetooth test procedure described in Appendix A.</p> 2041 2042 <a name="section-7.4.4"></a><h4>7.4.4. Near-Field Communications</h4> 2043 <p>Device implementations SHOULD include a transceiver and related hardware 2044 for Near-Field Communications (NFC). If a device implementation does include 2045 NFC hardware, then it:</p> 2046 <ul> 2047 <li>MUST report the android.hardware.nfc feature from the 2048 <code>android.content.pm.PackageManager.hasSystemFeature()</code> method. 2049 [<a href="#resources37">Resources, 37</a>]</li> 2050 <li>MUST be capable of reading and writing NDEF messages via the following NFC 2051 standards: 2052 <ul> 2053 <li>MUST be capable of acting as an NFC Forum reader/writer 2054 (as defined by the NFC Forum technical specification 2055 NFCForum-TS-DigitalProtocol-1.0) via the following NFC standards: 2056 <ul> 2057 <li>NfcA (ISO14443-3A)</li> 2058 <li>NfcB (ISO14443-3B) </li> 2059 <li>NfcF (JIS 6319-4)</li> 2060 <li>IsoDep (ISO 14443-4)</li> 2061 <li>NFC Forum Tag Types 1, 2, 3, 4 (defined by the NFC Forum)</li> 2062 </ul> 2063 </li> 2064 </ul> 2065 </li> 2066 <li>SHOULD be capable of reading and writing NDEF messages via the following 2067 NFC standards. Note that while the NFC standards below are stated as 2068 "SHOULD" for Android 4.2, the Compatibility Definition for a future 2069 version is planned to change these to "MUST". That is, these standards are 2070 optional in Android 4.2 but <b>will be required</b> in future versions. 2071 Existing and new devices that run Android 4.2 are <b>very strongly 2072 encouraged to meet these requirements in Android 4.2</b> so they will be 2073 able to upgrade to the future platform releases. 2074 <ul> 2075 <li>NfcV (ISO 15693)</li> 2076 </ul> 2077 </li> 2078 <li>MUST be capable of transmitting and receiving data via the following 2079 peer-to-peer standards and protocols: 2080 <ul> 2081 <li>ISO 18092</li> 2082 <li>LLCP 1.0 (defined by the NFC Forum)</li> 2083 <li>SDP 1.0 (defined by the NFC Forum)</li> 2084 <li>NDEF Push Protocol [<a href="#resources43">Resources, 43</a>]</li> 2085 <li>SNEP 1.0 (defined by the NFC Forum)</li> 2086 </ul> 2087 </li> 2088 <li>MUST include support for Android Beam [<a href="#resources65">Resources, 65</a>]: 2089 <ul> 2090 <li>MUST implement the SNEP default server. Valid NDEF messages received 2091 by the default SNEP server MUST be dispatched to applications using 2092 the android.nfc.ACTION_NDEF_DISCOVERED intent. Disabling Android Beam 2093 in settings MUST NOT disable dispatch of incoming NDEF message.</li> 2094 <li>Device implementations MUST honor the android.settings.NFCSHARING_SETTINGS intent 2095 to show NFC sharing settings [<a href="#resources67">Resources, 67</a>].</li> 2096 <li>MUST implement the NPP server. Messages received by the NPP server MUST 2097 be processed the same way as the SNEP default server.</li> 2098 <li>MUST implement a SNEP client and attempt to send outbound P2P NDEF to 2099 the default SNEP server when Android Beam is enabled. If no default 2100 SNEP server is found then the client MUST attempt to send to an NPP 2101 server.</li> 2102 <li>MUST allow foreground activities to set the outbound P2P NDEF message 2103 using android.nfc.NfcAdapter.setNdefPushMessage, and 2104 android.nfc.NfcAdapter.setNdefPushMessageCallback, and 2105 android.nfc.NfcAdapter.enableForegroundNdefPush.</li> 2106 <li>SHOULD use a gesture or on-screen confirmation, such as 'Touch to Beam', 2107 before sending outbound P2P NDEF messages.</li> 2108 <li>SHOULD enable Android Beam by default</li> 2109 <li>MUST support NFC Connection handover to Bluetooth when the device supports Bluetooth Object Push Profile. 2110 Device implementations must support connection handover to Bluetooth when using android.nfc.NfcAdapter.setBeamPushUris, 2111 by implementing the "Connection Handover version 1.2" [<a href="#resources60">Resources, 60</a>] 2112 and "Bluetooth Secure Simple Pairing Using NFC version 1.0" [<a href="#resources61">Resources, 61</a>] 2113 specs from the NFC Forum. Such an implementation SHOULD use SNEP GET 2114 requests for exchanging the handover request / select records over NFC, and it MUST 2115 use the Bluetooth Object Push Profile for the actual Bluetooth data transfer.</li> 2116 </ul> 2117 </li> 2118 <li>MUST poll for all supported technologies while in NFC discovery mode.</li> 2119 <li>SHOULD be in NFC discovery mode while the device is awake with the screen active 2120 and the lock-screen unlocked.</li> 2121 </ul> 2122 2123 <p>(Note that publicly available links are not available for the JIS, ISO, and 2124 NFC Forum specifications cited above.)</p> 2125 <p>Additionally, device implementations MAY include reader/writer support for 2126 the following MIFARE technologies.</p> 2127 <ul> 2128 <li>MIFARE Classic (NXP MF1S503x [<a href="#resources44">Resources, 44</a>], 2129 MF1S703x [<a href="#resources44">Resources, 44</a>])</li> 2130 <li>MIFARE Ultralight (NXP MF0ICU1 [<a href="#resources46">Resources, 46</a>], 2131 MF0ICU2 [<a href="#resources46">Resources, 46</a>])</li> 2132 <li>NDEF on MIFARE Classic (NXP AN130511 [<a href="#resources48">Resources, 48</a>], 2133 AN130411 [<a href="#resources49">Resources, 49</a>])</li> 2134 </ul> 2135 <p>Note that Android 4.2 includes APIs for these MIFARE types. If a 2136 device implementation supports MIFARE in the reader/writer role, it:</p> 2137 <ul> 2138 <li>MUST implement the corresponding Android APIs as documented by the 2139 Android SDK</li> 2140 <li>MUST report the feature com.nxp.mifare from the 2141 <code>android.content.pm.PackageManager.hasSystemFeature()</code> method. 2142 [<a href="#resources37">Resources, 37</a>] Note that this is not a standard 2143 Android feature, and as such does not appear as a constant on the 2144 <code>PackageManager</code> class.</li> 2145 <li>MUST NOT implement the corresponding Android APIs nor report the 2146 com.nxp.mifare feature unless it also implements general NFC support as 2147 described in this section</li> 2148 </ul> 2149 <p>If a device implementation does not include NFC hardware, it MUST NOT 2150 declare the android.hardware.nfc feature from the 2151 <code>android.content.pm.PackageManager.hasSystemFeature()</code> method [<a 2152 href="#resources37">Resources, 37</a>], and MUST implement the Android 4.2 NFC 2153 API as a no-op.</p> 2154 <p>As the classes <code>android.nfc.NdefMessage</code> and 2155 <code>android.nfc.NdefRecord</code> represent a protocol-independent data 2156 representation format, device implementations MUST implement these APIs even 2157 if they do not include support for NFC or declare the android.hardware.nfc 2158 feature.</p> 2159 <a name="section-7.4.5"></a><h4>7.4.5. Minimum Network Capability</h4> 2160 <p>Device implementations MUST include support for one or more forms of data 2161 networking. Specifically, device implementations MUST include support for at 2162 least one data standard capable of 200Kbit/sec or greater. Examples of 2163 technologies that satisfy this requirement include EDGE, HSPA, EV-DO, 802.11g, 2164 Ethernet, etc.</p> 2165 <p>Device implementations where a physical networking standard (such as 2166 Ethernet) is the primary data connection SHOULD also include support for at 2167 least one common wireless data standard, such as 802.11 (WiFi).</p> 2168 <p>Devices MAY implement more than one form of data connectivity.</p> 2169 2170 2171 <a name="section-7.5"></a><h3>7.5. Cameras</h3> 2172 <p>Device implementations SHOULD include a rear-facing camera, and MAY include 2173 a front-facing camera. A rear-facing camera is a camera located on the side of 2174 the device opposite the display; that is, it images scenes on the far side of 2175 the device, like a traditional camera. A front-facing camera is a camera 2176 located on the same side of the device as the display; that is, a camera 2177 typically used to image the user, such as for video conferencing and similar 2178 applications.</p> 2179 <a name="section-7.5.1"></a><h4>7.5.1. Rear-Facing Camera</h4> 2180 <p>Device implementations SHOULD include a rear-facing camera. If a device 2181 implementation includes a rear-facing camera, it:</p> 2182 <ul> 2183 <li>MUST have a resolution of at least 2 megapixels</li> 2184 <li>SHOULD have either hardware auto-focus, or software auto-focus implemented 2185 in the camera driver (transparent to application software)</li> 2186 <li>MAY have fixed-focus or EDOF (extended depth of field) hardware</li> 2187 <li>MAY include a flash. If the Camera includes a flash, the flash lamp MUST 2188 NOT be lit while an android.hardware.Camera.PreviewCallback instance has been 2189 registered on a Camera preview surface, unless the application has explicitly 2190 enabled the flash by enabling the <code>FLASH_MODE_AUTO</code> or 2191 <code>FLASH_MODE_ON</code> attributes of a <code>Camera.Parameters</code> 2192 object. Note that this constraint does not apply to the device's built-in 2193 system camera application, but only to third-party applications using 2194 <code>Camera.PreviewCallback</code>.</li> 2195 </ul> 2196 <a name="section-7.5.2"></a><h4>7.5.2. Front-Facing Camera</h4> 2197 <p>Device implementations MAY include a front-facing camera. If a device 2198 implementation includes a front-facing camera, it:</p> 2199 <ul> 2200 <li>MUST have a resolution of at least VGA (that is, 640x480 pixels)</li> 2201 <li>MUST NOT use a front-facing camera as the default for the Camera API. 2202 That is, the camera API in Android 4.2 has specific support for front-facing 2203 cameras, and device implementations MUST NOT configure the API to to treat a 2204 front-facing camera as the default rear-facing camera, even if it is the only 2205 camera on the device.</li> 2206 <li>MAY include features (such as auto-focus, flash, etc.) 2207 available to rear-facing cameras as described in Section 7.5.1.</li> 2208 <li>MUST horizontally reflect (i.e. mirror) the stream displayed by an app in a 2209 CameraPreview, as follows:</li> 2210 <ul> 2211 <li>If the device implementation is capable of being rotated by user (such as 2212 automatically via an accelerometer or manually via user input), the camera 2213 preview MUST be mirrored horizontally relative to the device's current 2214 orientation.</li> 2215 <li>If the current application has explicitly requested that the Camera 2216 display be rotated via a call to the 2217 <code>android.hardware.Camera.setDisplayOrientation()</code> [<a 2218 href="#resources50">Resources, 50</a>] method, the camera preview MUST be 2219 mirrored horizontally relative to the orientation specified by the 2220 application.</li> 2221 <li>Otherwise, the preview MUST be mirrored along the device's default horizontal axis.</li> 2222 </ul> 2223 <li>MUST mirror the image displayed by the postview in the same manner as 2224 the camera preview image stream. (If the device implementation does not 2225 support postview, this requirement obviously does not apply.)</li> 2226 <li>MUST NOT mirror the final captured still image or video streams returned 2227 to application callbacks or committed to media storage</li> 2228 </ul> 2229 <a name="section-7.5.3"></a><h4>7.5.3. Camera API Behavior</h4> 2230 <p>Device implementations MUST implement the following behaviors for the 2231 camera-related APIs, for both front- and rear-facing cameras:</p> 2232 <ol> 2233 <li>If an application has never called 2234 <code>android.hardware.Camera.Parameters.setPreviewFormat(int)</code>, then the 2235 device MUST use <code>android.hardware.PixelFormat.YCbCr_420_SP</code> for 2236 preview data provided to application callbacks.</li> 2237 <li>If an application registers an <code>android.hardware.Camera.PreviewCallback 2238 </code> instance and the system calls the <code>onPreviewFrame()</code> method 2239 when the preview format is YCbCr_420_SP, the data in the <code>byte[]</code> 2240 passed into <code>onPreviewFrame()</code> must further be in the NV21 encoding 2241 format. That is, NV21 MUST be the default.</li> 2242 <li>Device implementations MUST support the YV12 format (as denoted by the 2243 <code>android.graphics.ImageFormat.YV12</code> constant) for camera previews 2244 for both front- and rear-facing cameras. (The hardware video encoder and camera 2245 may use any native pixel format, but the device implementation MUST support conversion 2246 to YV12.)</li> 2247 </ol> 2248 <p>Device implementations MUST implement the full Camera API included in the 2249 Android 4.2 SDK documentation [<a href="#resources51">Resources, 51</a>]), 2250 regardless of whether the device includes hardware autofocus or other 2251 capabilities. For instance, cameras that lack autofocus MUST still call any 2252 registered <code>android.hardware.Camera.AutoFocusCallback</code> instances (even though 2253 this has no relevance to a non-autofocus camera.) Note that this does apply 2254 to front-facing cameras; for instance, even though most front-facing cameras 2255 do not support autofocus, the API callbacks must still be "faked" as 2256 described.</p> 2257 <p>Device implementations MUST recognize and honor each parameter name defined 2258 as a constant on the <code>android.hardware.Camera.Parameters</code> class, if the 2259 underlying hardware supports the feature. If the device hardware does not 2260 support a feature, the API must behave as documented. Conversely, Device 2261 implementations MUST NOT honor or recognize string constants passed 2262 to the <code>android.hardware.Camera.setParameters()</code> method other than 2263 those documented as constants on the 2264 <code>android.hardware.Camera.Parameters</code>. That is, 2265 device implementations MUST support all standard Camera parameters if the 2266 hardware allows, and MUST NOT support custom Camera parameter types. 2267 For instance, device implementations that support image capture using high dynamic range (HDR) 2268 imaging techniques MUST support camera parameter <code>Camera.SCENE_MODE_HDR</code> 2269 [<a href="#resources78">Resources, 78</a>]).</p> 2270 <p>Device implementations MUST broadcast the <code>Camera.ACTION_NEW_PICTURE</code> 2271 intent whenever a new picture is taken by the camera and the entry of the picture 2272 has been added to the media store.</p> 2273 <p>Device implementations MUST broadcast the <code>Camera.ACTION_NEW_VIDEO</code> 2274 intent whenever a new video is recorded by the camera and the entry of the picture 2275 has been added to the media store.</p> 2276 <a name="section-7.5.4"></a><h4>7.5.4. Camera Orientation</h4> 2277 <p>Both front- and rear-facing cameras, if present, MUST be oriented so that 2278 the long dimension of the camera aligns with the screen's long dimention. That 2279 is, when the device is held in the landscape orientation, cameras MUST 2280 capture images in the landscape orientation. This applies regardless of the 2281 device's natural orientation; that is, it applies to landscape-primary devices 2282 as well as portrait-primary devices.</p> 2283 2284 <a name="section-7.6"></a><h3>7.6. Memory and Storage</h3> 2285 <a name="section-7.6.1"></a><h4>7.6.1. Minimum Memory and Storage</h4> 2286 <p>Device implementations MUST have at least 340MB of memory available to the 2287 kernel and userspace. The 340MB MUST be in addition to any memory dedicated to 2288 hardware components such as radio, video, and so on that is not under the 2289 kernel's control.</p> 2290 <p>Device implementations MUST have at least 350MB of non-volatile storage 2291 available for application private data. That is, the <code>/data</code> partition MUST be at 2292 least 350MB.</p> 2293 <p>The Android APIs include a Download Manager that applications may use to 2294 download data files [<a href="#resources56">Resources, 56</a>]. The device 2295 implementation of the Download Manager MUST be capable of downloading individual 2296 files of at least 100MB in size to the default "cache" location.</p> 2297 <a name="section-7.6.2"></a><h4>7.6.2. Application Shared Storage</h4> 2298 <p>Device implementations MUST offer shared storage for applications. The 2299 shared storage provided MUST be at least 1GB in size.</p> 2300 <p>Device implementations MUST be configured with shared storage mounted by 2301 default, "out of the box". If the shared storage is not mounted on the Linux 2302 path <code>/sdcard</code>, then the device MUST include a Linux symbolic link 2303 from <code>/sdcard</code> to the actual mount point.</p> 2304 <p>Device implementations MUST enforce as documented the 2305 <code>android.permission.WRITE_EXTERNAL_STORAGE</code> permission on this 2306 shared storage. Shared storage MUST otherwise be writable by any application 2307 that obtains that permission.</p> 2308 <p>Device implementations MAY have hardware for user-accessible removable 2309 storage, such as a Secure Digital card. Alternatively, device implementations 2310 MAY allocate internal (non-removable) storage as shared storage for apps.</p> 2311 <p>Regardless of the form of shared storage used, device implementations MUST 2312 provide some mechanism to access the contents of shared storage from a host 2313 computer, such as USB mass storage (UMS) or Media Transfer Protocol (MTP). Device 2314 implementations MAY use USB mass storage, but SHOULD use Media Transfer 2315 Protocol. If the device implementation supports Media Transfer Protocol:</p> 2316 <ul> 2317 <li>The device implementation SHOULD be compatible with the reference Android 2318 MTP host, Android File Transfer [<a href="#resources57">Resources, 57</a>].</li> 2319 <li>The device implementation SHOULD report a USB device class of <code>0x00</code>.</li> 2320 <li>The device implementation SHOULD report a USB interface name of 'MTP'.</li> 2321 </ul> 2322 <p>If the device implementation lacks USB ports, it MUST provide a host 2323 computer with access to the contents of shared storage by some other means, 2324 such as a network file system.</p> 2325 <p>It is illustrative to consider two common examples. If a device 2326 implementation includes an SD card slot to satisfy the shared storage 2327 requirement, a FAT-formatted SD card 1GB in size or larger MUST be included 2328 with the device as sold to users, and MUST be mounted by default. 2329 Alternatively, if a device implementation uses internal fixed storage to 2330 satisfy this requirement, that storage MUST be 1GB in size or larger 2331 and mounted on <code>/sdcard</code> (or <code>/sdcard</code> 2332 MUST be a symbolic link to the physical location if it is mounted elsewhere.)</p> 2333 <p>Device implementations that include multiple shared storage paths (such as 2334 both an SD card slot and shared internal storage) SHOULD modify the core 2335 applications such as the media scanner and ContentProvider to transparently 2336 support files placed in both locations.</p> 2337 2338 <a name="section-7.7"></a><h3>7.7. USB</h3> 2339 <p>Device implementations SHOULD include a USB client port, and SHOULD include 2340 a USB host port.</p> 2341 <p>If a device implementation includes a USB client port:</p> 2342 <ul> 2343 <li>the port MUST be connectable to a USB host with a standard USB-A port</li> 2344 <li>the port SHOULD use the micro USB form factor on the device side. Existing and 2345 new devices that run Android 4.2 are <b>very strongly encouraged to meet these requirements 2346 in Android 4.2</b> so they will be able to upgrade to the future platform releases</li> 2347 <li>the port SHOULD be centered in the middle of an edge. Device implementations SHOULD either 2348 locate the port on the bottom of the device (according to natural orientation) or enable software 2349 screen rotation for all apps (including home screen), so that the display draws correctly when the device 2350 is oriented with the port at bottom. Existing and new devices that run Android 4.2 are <b>very strongly 2351 encouraged to meet these requirements in Android 4.2</b> so they will be able to upgrade to future platform releases.</li> 2352 <li>if the device has other ports (such as a non-USB charging port) it SHOULD be on the same edge as the 2353 micro-USB port</li> 2354 <li>it MUST allow a host connected to the device to access the contents of the 2355 shared storage volume using either USB mass storage or Media Transfer 2356 Protocol</li> 2357 <li>it MUST implement the Android Open Accessory API and specification as documented 2358 in the Android SDK documentation, and MUST declare support for the hardware 2359 feature <code>android.hardware.usb.accessory</code> [<a href="#resources52">Resources, 2360 52</a>]</li> 2361 <li>it MUST implement the USB audio class as documented in the Android SDK documentation [<a href="#resources66">Resources, 66</a>]</li> 2362 <li>it SHOULD implement support for USB battery charging specification [<a href="#resources64">Resources, 64</a>] 2363 Existing and new devices that run Android 4.2 are <b>very strongly encouraged to meet these requirements in Android 4.2</b> 2364 so they will be able to upgrade to the future platform releases</li> 2365 2366 </ul> 2367 <p>If a device implementation includes a USB host port:</p> 2368 <ul> 2369 <li>it MAY use a non-standard port form factor, but if so MUST ship with a 2370 cable or cables adapting the port to standard USB-A</li> 2371 <li>it MUST implement the Android USB host API as documented in the Android 2372 SDK, and MUST declare support for the hardware feature 2373 <code>android.hardware.usb.host</code> [<a href="#resources53">Resources, 53</a>]</li> 2374 </ul> 2375 <p>Device implementations MUST implement the Android Debug Bridge. If a device 2376 implementation omits a USB client port, it MUST implement the Android Debug 2377 Bridge via local-area network (such as Ethernet or 802.11)</p> 2378 2379 <a name="section-8"></a><h2>8. Performance Compatibility</h2> 2380 <p>Device implementations MUST meet the key performance metrics of an Android 2381 4.2 compatible device defined in the table below:</p> 2382 <table><tbody><tr> 2383 <td><b>Metric</b></td> 2384 <td><b>Performance Threshold</b></td> 2385 <td><b>Comments</b></td> 2386 </tr> 2387 <tr> 2388 <td>Application Launch Time</td> 2389 <td>The following applications should launch within the specified time.<ul> 2390 <li>Browser: less than 1300ms</li> 2391 <li>Contacts: less than 700ms</li> 2392 <li>Settings: less than 700ms</li> 2393 </ul></td> 2394 <td>The launch time is measured as the total time to 2395 complete loading the default activity for the application, including the time 2396 it takes to start the Linux process, load the Android package into the Dalvik 2397 VM, and call onCreate.</td> 2398 </tr> 2399 <tr> 2400 <td>Simultaneous Applications</td> 2401 <td>When multiple applications have been launched, re-launching an 2402 already-running application after it has been launched must take less than the 2403 original launch time.</td> 2404 <td> </td> 2405 </tr> 2406 </tbody> 2407 </table> 2408 2409 <a name="section-9"></a><h2>9. Security Model Compatibility</h2> 2410 <p>Device implementations MUST implement a security model consistent with the 2411 Android platform security model as defined in Security and Permissions 2412 reference document in the APIs [<a href="#resources54">Resources, 54</a>] in the 2413 Android developer documentation. Device implementations MUST support 2414 installation of self-signed applications without requiring any additional 2415 permissions/certificates from any third parties/authorities. Specifically, 2416 compatible devices MUST support the security mechanisms described in the 2417 follow sub-sections.</p> 2418 <a name="section-9.1"></a><h3>9.1. Permissions</h3> 2419 <p>Device implementations MUST support the Android permissions model as 2420 defined in the Android developer documentation [<a 2421 href="#resources54">Resources, 54</a>]. Specifically, 2422 implementations MUST enforce each permission defined as described in the SDK 2423 documentation; no permissions may be omitted, altered, or ignored. 2424 Implementations MAY add additional permissions, provided the new permission ID 2425 strings are not in the android.* namespace.</p> 2426 <a name="section-9.2"></a><h3>9.2. UID and Process Isolation</h3> 2427 <p>Device implementations MUST support the Android application sandbox model, 2428 in which each application runs as a unique Unix-style UID and in a separate 2429 process. Device implementations MUST support running multiple applications as 2430 the same Linux user ID, provided that the applications are properly signed and 2431 constructed, as defined in the Security and Permissions reference [<a 2432 href="#resources54">Resources, 54</a>].</p> 2433 <a name="section-9.3"></a><h3>9.3. Filesystem Permissions</h3> 2434 <p>Device implementations MUST support the Android file access permissions 2435 model as defined in as defined in the Security and Permissions reference [<a 2436 href="#resources54">Resources, 54</a>].</p> 2437 <a name="section-9.4"></a><h3>9.4. Alternate Execution Environments</h3> 2438 <p>Device implementations MAY include runtime environments that execute 2439 applications using some other software or technology than the Dalvik virtual 2440 machine or native code. However, such alternate execution environments MUST 2441 NOT compromise the Android security model or the security of installed Android 2442 applications, as described in this section.</p> 2443 <p>Alternate runtimes MUST themselves be Android applications, and abide by 2444 the standard Android security model, as described elsewhere in Section 9.</p> 2445 <p>Alternate runtimes MUST NOT be granted access to resources protected by 2446 permissions not requested in the runtime's AndroidManifest.xml file via the 2447 <code><uses-permission></code> mechanism.</p> 2448 <p>Alternate runtimes MUST NOT permit applications to make use of features 2449 protected by Android permissions restricted to system applications.</p> 2450 <p>Alternate runtimes MUST abide by the Android sandbox model. Specifically:</p> 2451 <ul> 2452 <li>Alternate runtimes SHOULD install apps via the PackageManager into 2453 separate Android sandboxes (that is, Linux user IDs, etc.)</li> 2454 <li>Alternate runtimes MAY provide a single Android sandbox shared by all 2455 applications using the alternate runtime</li> 2456 <li>Alternate runtimes and installed applications using an alternate runtime 2457 MUST NOT reuse the sandbox of any other app installed on the device, except 2458 through the standard Android mechanisms of shared user ID and signing 2459 certificate</li> 2460 <li>Alternate runtimes MUST NOT launch with, grant, or be granted access to 2461 the sandboxes corresponding to other Android applications</li> 2462 </ul> 2463 <p>Alternate runtimes MUST NOT be launched with, be granted, or grant to other 2464 applications any privileges of the superuser (root), or of any other user ID.</p> 2465 <p>The .apk files of alternate runtimes MAY be included in the system image of 2466 a device implementation, but MUST be signed with a key distinct 2467 from the key used to sign other applications included with the device 2468 implementation.</p> 2469 <p>When installing applications, alternate runtimes MUST obtain user consent 2470 for the Android permissions used by the application. That is, if an 2471 application needs to make use of a device resource for which there is a 2472 corresponding Android permission (such as Camera, GPS, etc.), the alternate 2473 runtime MUST inform the user that the application will be able to access 2474 that resource. If the runtime environment does not record application 2475 capabilities in this manner, the runtime environment MUST list all 2476 permissions held by the runtime itself when installing any application 2477 using that runtime.</p> 2478 2479 <a name="section-9.5"></a><h3>9.5. Multi-User Support </h3> 2480 <p>Android 4.2 includes support for multiple users and provides support for full user isolation 2481 [<a href="#resources70">Resources, 70</a>].</p> 2482 <p>Device implementations MUST meet these requirements related to multi-user support[<a href="#resources71">Resources, 71</a>]:</p> 2483 <ul> 2484 <li>As the behavior of the telephony APIs on devices with multiple users is currently undefined, device implementations that 2485 declare android.hardware.telephony MUST NOT enable multi-user support. </li> 2486 <li>Device implementations MUST, for each user, implement a security model consistent with the Android platform security model 2487 as defined in Security and Permissions reference document in the APIs [Resources, 54]</li> 2488 </ul> 2489 </p> 2490 2491 <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. 2492 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. 2493 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 2494 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 2495 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 2496 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 2497 project includes an implementation that uses internal device storage for application external storage APIs; device implementations SHOULD use this configuration and software implementation. 2498 Device implementations that include multiple external storage paths MUST NOT allow Android applications to write to the secondary external storage</p> 2499 2500 <a name="section-9.6"></a><h3>9.6. Premium SMS Warning</h3> 2501 <p>Android 4.2 includes support for warning users for any outgoing premium SMS message. Premium SMS messages are text messages sent to a service registered with a carrier that may incur a charge to the user. 2502 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. 2503 The upstream Android open-source project provides an implementation that satisfies this requirement. 2504 </p> 2505 2506 <a name="section-10"></a><h2>10. Software Compatibility Testing</h2> 2507 <p>Device implementations MUST pass all tests described in this section.</p> 2508 <p>However, note that no software test package is fully comprehensive. For 2509 this reason, device implementers are very strongly encouraged to make the 2510 minimum number of changes as possible to the reference and preferred 2511 implementation of Android 4.2 available from the Android Open Source Project. 2512 This will minimize the risk of introducing bugs that create incompatibilities 2513 requiring rework and potential device updates.</p> 2514 <a name="section-10.1"></a><h3>10.1. Compatibility Test Suite</h3> 2515 <p>Device implementations MUST pass the Android Compatibility Test Suite (CTS) 2516 [<a href="#resources02">Resources, 2</a>] available from the Android Open Source 2517 Project, using the final shipping software on the device. Additionally, device 2518 implementers SHOULD use the reference implementation in the Android Open 2519 Source tree as much as possible, and MUST ensure compatibility in cases of 2520 ambiguity in CTS and for any reimplementations of parts of the reference 2521 source code.</p> 2522 <p>The CTS is designed to be run on an actual device. Like any software, the 2523 CTS may itself contain bugs. The CTS will be versioned independently of this 2524 Compatibility Definition, and multiple revisions of the CTS may be released 2525 for Android 4.2. Device implementations MUST pass the latest CTS version 2526 available at the time the device software is completed.</p> 2527 <a name="section-10.2"></a><h3>10.2. CTS Verifier</h3> 2528 <p>Device implementations MUST correctly execute all applicable cases in the 2529 CTS Verifier. The CTS Verifier is included with the Compatibility Test Suite, 2530 and is intended to be run by a human operator to test functionality that 2531 cannot be tested by an automated system, such as correct functioning of a 2532 camera and sensors.</p> 2533 <p>The CTS Verifier has tests for many kinds of hardware, including some 2534 hardware that is optional. Device implementations MUST pass all tests for 2535 hardware which they possess; for instance, if a device possesses an 2536 accelerometer, it MUST correctly execute the Accelerometer test case in the 2537 CTS Verifier. Test cases for features noted as optional by this Compatibility 2538 Definition Document MAY be skipped or omitted.</p> 2539 <p>Every device and every build MUST correctly run the CTS Verifier, as noted 2540 above. However, since many builds are very similar, device implementers are 2541 not expected to explicitly run the CTS Verifier on builds that differ only in 2542 trivial ways. Specifically, device implementations that differ from an 2543 implementation that has passed the CTS Verfier only by the set of included 2544 locales, branding, etc. MAY omit the CTS Verifier test.</p> 2545 <a name="section-10.3"></a><h3>10.3. Reference Applications</h3> 2546 <p>Device implementers MUST test implementation compatibility using the 2547 following open source applications:</p> 2548 <ul> 2549 <li>The "Apps for Android" applications [<a href="#resources55">Resources, 55</a>]</li> 2550 <li>Replica Island (available in Android Market)</li> 2551 </ul> 2552 <p>Each app above MUST launch and behave correctly on the implementation, for 2553 the implementation to be considered compatible.</p> 2554 2555 2556 <a name="section-11"></a><h2>11. Updatable Software</h2> 2557 <p>Device implementations MUST include a mechanism to replace the entirety of 2558 the system software. The mechanism need not perform "live" upgrades - that 2559 is, a device restart MAY be required.</p> 2560 <p>Any method can be used, provided that it can replace the entirety of the 2561 software preinstalled on the device. For instance, any of the following 2562 approaches will satisfy this requirement:</p> 2563 <ul> 2564 <li>Over-the-air (OTA) downloads with offline update via reboot</li> 2565 <li>"Tethered" updates over USB from a host PC</li> 2566 <li>"Offline" updates via a reboot and update from a file on removable 2567 storage</li> 2568 </ul> 2569 <p>The update mechanism used MUST support updates without wiping user data. 2570 That is, the update mechanism MUST preserve application private data 2571 and application shared data. Note that the upstream Android software includes 2572 an update mechanism that satisfies this requirement.</p> 2573 <p>If an error is found in a device implementation after it has been released 2574 but within its reasonable product lifetime that is determined in consultation 2575 with the Android Compatibility Team to affect the compatibility of third-party 2576 applications, the device implementer MUST correct the error via a software 2577 update available that can be applied per the mechanism just described.</p> 2578 2579 <a name="section-12"></a><h2>12. Contact Us</h2> 2580 <p>You can contact the document authors at <a 2581 href="mailto:compatibility (a] android.com">compatibility (a] android.com</a> for 2582 clarifications and to bring up any issues that you think the document does not 2583 cover.</p> 2584 2585 <div style="page-break-before: always;"></div> 2586 2587 <a name="appendix-A"></a><h2>Appendix A - Bluetooth Test Procedure</h2> 2588 <p>The Compatibility Test Suite includes cases that cover basic operation of 2589 the Android RFCOMM Bluetooth API. However, since Bluetooth is a communications 2590 protocol between devices, it cannot be fully tested by unit tests running on a 2591 single device. Consequently, device implementations MUST also pass the 2592 human-operated Bluetooth test procedure described below.</p> 2593 <p>The test procedure is based on the BluetoothChat sample app included in the 2594 Android open source project tree. The procedure requires two devices:</p> 2595 <ul> 2596 <li>a candidate device implementation running the software build to be tested</li> 2597 <li>a separate device implementation already known to be compatible, and of a 2598 model from the device implementation being tested - that is, a "known 2599 good" device implementation</li> 2600 </ul> 2601 <p>The test procedure below refers to these devices as the "candidate" and "known 2602 good" devices, respectively.</p> 2603 <h3>Setup and Installation</h3> 2604 <ol> 2605 <li>Build BluetoothChat.apk via 'make samples' from an Android source code tree</li> 2606 <li>Install BluetoothChat.apk on the known-good device</li> 2607 <li>Install BluetoothChat.apk on the candidate device</li> 2608 </ol> 2609 <h3>Test Bluetooth Control by Apps</h3> 2610 <ol> 2611 <li>Launch BluetoothChat on the candidate device, while Bluetooth is disabled</li> 2612 <li>Verify that the candidate device either turns on Bluetooth, or prompts the user with a dialog to turn on Bluetooth</li> 2613 </ol> 2614 <h3>Test Pairing and Communication</h3> 2615 <ol> 2616 <li>Launch the Bluetooth Chat app on both devices</li> 2617 <li>Make the known-good device discoverable from within BluetoothChat (using the Menu)</li> 2618 <li>On the candidate device, scan for Bluetooth devices from within BluetoothChat (using the Menu) and pair with the known-good device</li> 2619 <li>Send 10 or more messages from each device, and verify that the other device receives them correctly</li> 2620 <li>Close the BluetoothChat app on both devices by pressing <b>Home</b></li> 2621 <li>Unpair each device from the other, using the device Settings app</li> 2622 </ol> 2623 <h3>Test Pairing and Communication in the Reverse Direction</h3> 2624 <ol> 2625 <li>Launch the Bluetooth Chat app on both devices.</li> 2626 <li>Make the candidate device discoverable from within BluetoothChat (using the Menu).</li> 2627 <li>On the known-good device, scan for Bluetooth devices from within BluetoothChat (using the Menu) and pair with the candidate device.</li> 2628 <li>Send 10 or messages from each device, and verify that the other device receives them correctly.</li> 2629 <li>Close the Bluetooth Chat app on both devices by pressing Back repeatedly to get to the Launcher.</li> 2630 </ol> 2631 <h3>Test Re-Launches</h3> 2632 <ol> 2633 <li>Re-launch the Bluetooth Chat app on both devices.</li> 2634 <li>Send 10 or messages from each device, and verify that the other device receives them correctly.</li> 2635 </ol> 2636 <p>Note: the above tests have some cases which end a test section by using 2637 Home, and some using Back. These tests are not redundant and are not optional: 2638 the objective is to verify that the Bluetooth API and stack works correctly 2639 both when Activities are explicitly terminated (via the user pressing Back, 2640 which calls finish()), and implicitly sent to background (via the user 2641 pressing Home.) Each test sequence MUST be performed as described.</p> 2642 <div id="footerContent" xmlns:pdf="http://whatever"> 2643 <pdf:pagenumber/> 2644 </div> 2645 </body> 2646 </html> 2647
