1 <html devsite> 2 <head> 3 <title>Android 4.2 Compatibility Definition</title> 4 <link rel="stylesheet" type="text/css" href="cdd.css"/> 5 </head> 6 <body> 7 <!-- 8 <span style="color: red; font-weight: bold;"><h2>Revision 1</h2></span><br/> 9 <span style="color: red;">Last updated: October 17, 2012</span> 10 --> 11 <p><b><font color="red">Revision 2</font></b><br/> 12 Last updated: Feb 17, 2013 13 </p> 14 <p>Copyright © 2012, Google Inc. All rights reserved.<br/> 15 <a href="mailto:compatibility (a] android.com">compatibility (a] android.com</a> 16 </p> 17 18 <h2> Table of Contents</h2> 19 <div style="margin-left: 2em;"> 20 <a href="#section-1">1. Introduction</a><br/> 21 <a href="#section-2">2. Resources</a><br/> 22 <a href="#section-3">3. Software</a><br/> 23 <div style="margin-left: 2em;"> 24 <a href="#section-3.1">3.1. Managed API Compatibility</a><br/> 25 <a href="#section-3.2">3.2. Soft API Compatibility</a><br/> 26 <div style="margin-left: 2em;"> 27 <a href="#section-3.2.1">3.2.1. Permissions</a><br/> 28 <a href="#section-3.2.2">3.2.2. Build Parameters</a><br/> 29 <a href="#section-3.2.3">3.2.3. Intent Compatibility</a><br/> 30 <div style="margin-left: 2em;"> 31 <a href="#section-3.2.3.1">3.2.3.1. Core Application Intents</a><br/> 32 <a href="#section-3.2.3.2">3.2.3.2. Intent Overrides</a><br/> 33 <a href="#section-3.2.3.3">3.2.3.3. Intent Namespaces</a><br/> 34 <a href="#section-3.2.3.4">3.2.3.4. Broadcast Intents</a><br/> 35 </div> 36 </div> 37 <a href="#section-3.3">3.3. Native API Compatibility</a><br/> 38 <div style="margin-left: 2em;"> 39 <a href="#section-3.3.1">3.3.1 Application Binary Interfaces</a><br/> 40 </div> 41 <a href="#section-3.4">3.4. Web Compatibility</a><br/> 42 <div style="margin-left: 2em;"> 43 <a href="#section-3.4.1">3.4.1. WebView Compatibility</a><br/> 44 <a href="#section-3.4.2">3.4.2. Browser Compatibility</a><br/> 45 </div> 46 <a href="#section-3.5">3.5. API Behavioral Compatibility</a><br/> 47 <a href="#section-3.6">3.6. API Namespaces</a><br/> 48 <a href="#section-3.7">3.7. Virtual Machine Compatibility</a><br/> 49 <a href="#section-3.8">3.8. User Interface Compatibility</a><br/> 50 <div style="margin-left: 2em;"> 51 <a href="#section-3.8.1">3.8.1. Widgets</a><br/> 52 <a href="#section-3.8.2">3.8.2. Notifications</a><br/> 53 <a href="#section-3.8.3">3.8.3. Search</a><br/> 54 <a href="#section-3.8.4">3.8.4. Toasts</a><br/> 55 <a href="#section-3.8.5">3.8.5. Themes</a><br/> 56 <a href="#section-3.8.6">3.8.6. Live Wallpapers</a><br/> 57 <a href="#section-3.8.7">3.8.7. Recent Application Display</a><br/> 58 <a href="#section-3.8.8">3.8.8. Input Management Settings</a><br/> 59 <a href="#section-3.8.9">3.8.9. Lock and Home Screen Widgets</a><br/> 60 <a href="#section-3.8.10">3.8.10. Lock Screen Media Remote Control</a><br/> 61 <a href="#section-3.8.11">3.8.11. Dreams</a><br/> 62 </div> 63 <a href="#section-3.9">3.9 Device Administration</a><br/> 64 <a href="#section-3.10">3.10 Accessibility</a><br/> 65 <a href="#section-3.11">3.11 Text-to-Speech</a><br/> 66 </div> 67 <a href="#section-4">4. Application Packaging Compatibility</a><br/> 68 <a href="#section-5">5. Multimedia Compatibility</a><br/> 69 <div style="margin-left: 2em;"> 70 <a href="#section-5.1">5.1. Media Codecs</a><br/> 71 <a href="#section-5.2">5.2. Video Encoding</a><br/> 72 <a href="#section-5.3">5.3. Video Decoding</a><br/> 73 <a href="#section-5.4">5.4. Audio Recording</a><br/> 74 <a href="#section-5.5">5.5. Audio Latency</a><br/> 75 <a href="#section-5.6">5.6. Network Protocols</a><br/> 76 </div> 77 <a href="#section-6">6. Developer Tools and Options Compatibility</a><br/> 78 <div style="margin-left: 2em;"> 79 <a href="#section-6.1">6.1. Developer Tools</a><br/> 80 <a href="#section-6.2">6.2. Developer Options</a><br/> 81 </div> 82 <a href="#section-7">7. Hardware Compatibility</a><br/> 83 <div style="margin-left: 2em;"> 84 <a href="#section-7.1">7.1. Display and Graphics</a><br/> 85 <div style="margin-left: 2em;"> 86 <a href="#section-7.1.1">7.1.1. Screen Configuration</a><br/> 87 <a href="#section-7.1.2">7.1.2. Display Metrics</a><br/> 88 <a href="#section-7.1.3">7.1.3. Screen Orientation</a><br/> 89 <a href="#section-7.1.4">7.1.4. 2D and 3D Graphics Accleration</a><br/> 90 <a href="#section-7.1.5">7.1.5. Legacy Application Compatibility Mode</a><br/> 91 <a href="#section-7.1.6">7.1.6. Screen Types</a><br/> 92 <a href="#section-7.1.7">7.1.7. Screen Technology</a><br/> 93 <a href="#section-7.1.8">7.1.8. External Displays</a><br/> 94 </div> 95 <a href="#section-7.2">7.2. Input Devices</a><br/> 96 <div style="margin-left: 2em;"> 97 <a href="#section-7.2.1">7.2.1. Keyboard</a><br/> 98 <a href="#section-7.2.2">7.2.2. Non-touch Navigation</a><br/> 99 <a href="#section-7.2.3">7.2.3. Navigation keys</a><br/> 100 <a href="#section-7.2.4">7.2.4. Touchscreen input</a><br/> 101 </div> 102 <a href="#section-7.3">7.3. Sensors</a><br/> 103 <div style="margin-left: 2em;"> 104 <a href="#section-7.3.1">7.3.1. Accelerometer</a><br/> 105 <a href="#section-7.3.2">7.3.2. Magnetometer</a><br/> 106 <a href="#section-7.3.3">7.3.3. GPS</a><br/> 107 <a href="#section-7.3.4">7.3.4. Gyroscope</a><br/> 108 <a href="#section-7.3.5">7.3.5. Barometer</a><br/> 109 <a href="#section-7.3.6">7.3.6. Thermometer</a><br/> 110 <a href="#section-7.3.7">7.3.7. Photometer</a><br/> 111 <a href="#section-7.3.8">7.3.8. Proximity Sensor</a><br/> 112 </div> 113 <a href="#section-7.4">7.4. Data Connectivity</a><br/> 114 <div style="margin-left: 2em;"> 115 <a href="#section-7.4.1">7.4.1. Telephony</a><br/> 116 <a href="#section-7.4.2">7.4.2. IEEE 802.11 (WiFi)</a><br/> 117 <div style="margin-left: 2em;"> 118 <a href="#section-7.4.2.1">7.4.2.1. WiFi Direct</a><br/> 119 </div> 120 <a href="#section-7.4.3">7.4.3. Bluetooth</a><br/> 121 <a href="#section-7.4.4">7.4.4. Near-Field Communications</a><br/> 122 <a href="#section-7.4.5">7.4.5. Minimum Network Capability</a><br/> 123 </div> 124 <a href="#section-7.5">7.5. Cameras</a><br/> 125 <div style="margin-left: 2em;"> 126 <a href="#section-7.5.1">7.5.1. Rear-Facing Camera</a><br/> 127 <a href="#section-7.5.2">7.5.2. Front-Facing Camera</a><br/> 128 <a href="#section-7.5.3">7.5.3. Camera API Behavior</a><br/> 129 <a href="#section-7.5.4">7.5.4. Camera Orientation</a><br/> 130 </div> 131 <a href="#section-7.6">7.6. Memory and Storage</a><br/> 132 <div style="margin-left: 2em;"> 133 <a href="#section-7.6.1">7.6.1. Minimum Memory and Storage</a><br/> 134 <a href="#section-7.6.2">7.6.2. Application Shared Storage</a><br/> 135 </div> 136 <a href="#section-7.7">7.7. USB</a><br/> 137 </div> 138 <a href="#section-8">8. Performance Compatibility</a><br/> 139 <a href="#section-9">9. Security Model Compatibility</a><br/> 140 <div style="margin-left: 2em;"> 141 <a href="#section-9.1">9.1. Permissions</a><br/> 142 <a href="#section-9.2">9.2. UID and Process Isolation</a><br/> 143 <a href="#section-9.3">9.3. Filesystem Permissions</a><br/> 144 <a href="#section-9.4">9.4. Alternate Execution Environments</a><br/> 145 <a href="#section-9.5">9.5. Multi-User Support</a><br/> 146 <a href="#section-9.6">9.6. Premium SMS Warning</a><br/> 147 </div> 148 <a href="#section-10">10. Software Compatibility Testing</a><br/> 149 <div style="margin-left: 2em;"> 150 <a href="#section-10.1">10.1. Compatibility Test Suite</a><br/> 151 <a href="#section-10.2">10.2. CTS Verifier</a><br/> 152 <a href="#section-10.3">10.3. Reference Applications</a><br/> 153 </div> 154 <a href="#section-11">11. Updatable Software</a><br/> 155 <a href="#section-12">12. Contact Us</a><br/> 156 <a href="#appendix-A">Appendix A - Bluetooth Test Procedure</a><br/> 157 </div> 158 159 <div style="page-break-before: always;"></div> 160 161 <a name="section-1"></a><h2>1. Introduction</h2> 162 <p>This document enumerates the requirements that must be met in order for 163 devices to be compatible with Android 4.2.</p> 164 <p>The use of "must", "must not", "required", "shall", "shall not", "should", 165 "should not", "recommended", "may" and "optional" is per the IETF standard 166 defined in RFC2119 [<a href="#resources01">Resources, 1</a>].</p> 167 <p>As used in this document, a "device implementer" or "implementer" is a 168 person or organization developing a hardware/software solution running Android 169 4.2. A "device implementation" or "implementation" is the hardware/software 170 solution so developed.</p> 171 <p>To be considered compatible with Android 4.2, device implementations 172 MUST meet the requirements presented in this Compatibility Definition, 173 including any documents incorporated via reference.</p> 174 <p>Where this definition or the software tests described in <a 175 href="#section-10">Section 10</a> is silent, ambiguous, or incomplete, it is 176 the responsibility of the device implementer to ensure compatibility with 177 existing implementations.</p> 178 <p>For this reason, the Android Open Source Project [<a 179 href="#resources03">Resources, 3</a>] is both the reference and preferred 180 implementation of Android. Device implementers are strongly encouraged to base 181 their implementations to the greatest extent possible on the "upstream" source 182 code available from the Android Open Source Project. While some components can 183 hypothetically be replaced with alternate implementations this practice is 184 strongly discouraged, as passing the software tests will become substantially 185 more difficult. It is the implementer's responsibility to ensure full 186 behavioral compatibility with the standard Android implementation, including 187 and beyond the Compatibility Test Suite. Finally, note that certain component 188 substitutions and modifications are explicitly forbidden by this document.</p> 189 <a name="section-2"></a><h2>2. Resources</h2> 190 <ol> 191 <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> 192 <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> 193 <a name="resources03"></a><li>Android Open Source Project: <a href="http://source.android.com/">http://source.android.com/</a></li> 194 <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> 195 <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> 196 <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> 197 <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> 198 <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> 199 <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> 200 <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> 201 <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> 202 <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> 203 <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> 204 <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> 205 <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> 206 <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> 207 <a name="resources17"></a><li>Dalvik Virtual Machine specification: available in the Android source code, at dalvik/docs</li> 208 <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> 209 <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> 210 <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> 211 <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> 212 <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> 213 <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> 214 <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> 215 <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> 216 <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> 217 <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> 218 <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> 219 <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> 220 <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> 221 <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> 222 <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> 223 <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> 224 <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> 225 <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> 226 <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> 227 <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> 228 <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> 229 <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> 230 <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> 231 <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> 232 <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> 233 <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> 234 <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> 235 <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> 236 <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> 237 <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> 238 <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> 239 <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> 240 <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> 241 <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> 242 <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> 243 <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> 244 <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> 245 <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> 246 <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> 247 <a name="resources57"></a><li>Android File Transfer: <a href="http://www.android.com/filetransfer">http://www.android.com/filetransfer</a></li> 248 <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> 249 <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> 250 <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> 251 <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> 252 <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> 253 <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> 254 <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> 255 <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> 256 <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> 257 <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> 258 <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> 259 <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> 260 <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> 261 <a name="resources71"></a><li>External Storage reference: <a href="http://source.android.com/tech/storage">http://source.android.com/tech/storage</a></li> 262 <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> 263 <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> 264 <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> 265 <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> 266 <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> 267 <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> 268 </ol> 269 <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> 270 <p>Many of these resources are derived directly or indirectly from the Android 271 4.2 SDK, and will be functionally identical to the information in that SDK's 272 documentation. In any cases where this Compatibility Definition or the 273 Compatibility Test Suite disagrees with the SDK documentation, the SDK 274 documentation is considered authoritative. Any technical details provided in 275 the references included above are considered by inclusion to be part of this 276 Compatibility Definition.</p> 277 278 <a name="section-3"></a><h2>3. Software</h2> 279 <a name="section-3.1"></a><h3>3.1. Managed API Compatibility</h3> 280 <p>The managed (Dalvik-based) execution environment is the primary vehicle for 281 Android applications. The Android application programming interface (API) is 282 the set of Android platform interfaces exposed to applications running in the 283 managed VM environment. Device implementations MUST provide complete 284 implementations, including all documented behaviors, of any documented API 285 exposed by the Android 4.2 SDK [<a href="#resources04">Resources, 4</a>].</p> 286 <p>Device implementations MUST NOT omit any managed APIs, alter API interfaces 287 or signatures, deviate from the documented behavior, or include no-ops, except 288 where specifically allowed by this Compatibility Definition.</p> 289 <p>This Compatibility Definition permits some types of hardware for which 290 Android includes APIs to be omitted by device implementations. In such cases, 291 the APIs MUST still be present and behave in a reasonable way. See 292 <a href="#section-7">Section 7</a> for specific requirements for this scenario. 293 </p> 294 295 <a name="section-3.2"></a><h3>3.2. Soft API Compatibility</h3> 296 <p>In addition to the managed APIs from Section 3.1, Android also includes a 297 significant runtime-only "soft" API, in the form of such things such as 298 Intents, permissions, and similar aspects of Android applications that cannot 299 be enforced at application compile time.</p> 300 <a name="section-3.2.1"></a><h4>3.2.1. Permissions</h4> 301 <p>Device implementers MUST support and enforce all permission constants as 302 documented by the Permission reference page [<a 303 href="#resources05">Resources, 5</a>]. Note that Section 10 lists additional 304 requirements related to the Android security model.</p> 305 <a name="section-3.2.2"></a><h4>3.2.2. Build Parameters</h4> 306 <p>The Android APIs include a number of constants on the <code>android.os.Build</code> 307 class [<a href="#resources06">Resources, 6</a>] that are intended to describe 308 the current device. To provide consistent, meaningful values across device 309 implementations, the table below includes additional restrictions on the 310 formats of these values to which device implementations MUST conform.</p> 311 <table> 312 <tbody> 313 <tr> 314 <td><b>Parameter</b></td> 315 <td><b>Comments</b></td> 316 </tr> 317 <tr> 318 <td>android.os.Build.VERSION.RELEASE</td> 319 <td>The version of the currently-executing Android system, in human-readable 320 format. This field MUST have one of the string values defined in [<a 321 href="#resources07">Resources, 7</a>].</td> 322 </tr> 323 <tr> 324 <td>android.os.Build.VERSION.SDK</td> 325 <td>The version of the currently-executing Android system, in a format 326 accessible to third-party application code. For Android 4.2, this 327 field MUST have the integer value 17.</td> 328 </tr> 329 <tr> 330 <td>android.os.Build.VERSION.SDK_INT</td> 331 <td>The version of the currently-executing Android system, in a format 332 accessible to third-party application code. For Android 4.2, this 333 field MUST have the integer value 17.</td> 334 </tr> 335 <tr> 336 <td>android.os.Build.VERSION.INCREMENTAL</td> 337 <td>A value chosen by the device implementer designating the specific build of 338 the currently-executing Android system, in human-readable format. This value 339 MUST NOT be re-used for different builds made available to end users. A typical use 340 of this field is to indicate which build number or source-control change 341 identifier was used to generate the build. There are no requirements on the 342 specific format of this field, except that it MUST NOT be null or the empty 343 string ("").</td> 344 </tr> 345 <tr> 346 <td>android.os.Build.BOARD</td> 347 <td>A value chosen by the device implementer identifying the specific internal 348 hardware used by the device, in human-readable format. A possible use of this 349 field is to indicate the specific revision of the board powering the device. 350 The value of this field MUST be encodable as 7-bit ASCII and match the regular expression 351 <code>"^[a-zA-Z0-9.,_-]+$"</code>.</td> 352 </tr> 353 <tr> 354 <td>android.os.Build.BRAND</td> 355 <td>A value chosen by the device implementer identifying the name of the 356 company, organization, individual, etc. who produced the device, in 357 human-readable format. A possible use of this field is to indicate the OEM 358 and/or carrier who sold the device. The value of this field MUST be 359 encodable as 7-bit ASCII and match the regular expression 360 <code>"^[a-zA-Z0-9.,_-]+$"</code>. 361 </td> 362 </tr> 363 <tr> 364 <td>android.os.Build.CPU_ABI</td> 365 <td>The name of the instruction set (CPU type + ABI convention) of native code. 366 See <a href="#section-3.3">Section 3.3: Native API Compatibility</a>. 367 </td> 368 </tr> 369 <tr> 370 <td>android.os.Build.CPU_ABI2</td> 371 <td>The name of the second instruction set (CPU type + ABI convention) of native code. 372 See <a href="#section-3.3">Section 3.3: Native API Compatibility</a>. 373 </td> 374 </tr> 375 <tr> 376 <td>android.os.Build.DEVICE</td> 377 <td>A value chosen by the device implementer identifying the specific 378 configuration or revision of the body (sometimes called "industrial design") 379 of the device. The value of this field MUST be encodable as 7-bit ASCII and 380 match the regular expression <code>"^[a-zA-Z0-9.,_-]+$"</code>.</td> 381 </tr> 382 <tr> 383 <td>android.os.Build.FINGERPRINT</td> 384 <td>A string that uniquely identifies this build. It SHOULD be reasonably 385 human-readable. It MUST follow this template: 386 <br/><code>$(BRAND)/$(PRODUCT)/$(DEVICE):$(VERSION.RELEASE)/$(ID)/$(VERSION.INCREMENTAL):$(TYPE)/$(TAGS)</code><br/> 387 For example: 388 <br/><code>acme/mydevice/generic:4.2/JRN53/3359:userdebug/test-keys</code><br/> 389 The fingerprint MUST NOT include whitespace characters. If other fields included in the 390 template above have whitespace characters, they MUST be replaced in the build 391 fingerprint with another character, such as the underscore ("_") character. 392 The value of this field MUST be encodable as 7-bit ASCII.</td> 393 </tr> 394 <tr> 395 <td>android.os.Build.HARDWARE</td> 396 <td>The name of the hardware (from the kernel command line or /proc). It SHOULD be 397 reasonably human-readable. The value of this field MUST be encodable as 7-bit ASCII and 398 match the regular expression <code>"^[a-zA-Z0-9.,_-]+$"</code>.</td> 399 </tr> 400 <tr> 401 <td>android.os.Build.HOST</td> 402 <td>A string that uniquely identifies the host the build was built on, in 403 human readable format. There are no requirements on the specific format of 404 this field, except that it MUST NOT be null or the empty string ("").</td> 405 </tr> 406 <tr> 407 <td>android.os.Build.ID</td> 408 <td>An identifier chosen by the device implementer to refer to a specific 409 release, in human readable format. This field can be the same as 410 android.os.Build.VERSION.INCREMENTAL, but SHOULD be a value sufficiently 411 meaningful for end users to distinguish between software builds. The value of 412 this field MUST be encodable as 7-bit ASCII and match the regular expression 413 <code>"^[a-zA-Z0-9.,_-]+$"</code>. 414 </td> 415 </tr> 416 <tr> 417 <td>android.os.Build.MANUFACTURER</td> 418 <td>The trade name of the Original Equipment Manufacturer (OEM) of the product. 419 There are no requirements on the specific format of this field, except that it 420 MUST NOT be null or the empty string ("").</td> 421 </tr> 422 <tr> 423 <td>android.os.Build.MODEL</td> 424 <td>A value chosen by the device implementer containing the name of the device 425 as known to the end user. This SHOULD be the same name under which the device 426 is marketed and sold to end users. There are no requirements on the specific 427 format of this field, except that it MUST NOT be null or the empty string 428 ("").</td> 429 </tr> 430 <tr> 431 <td>android.os.Build.PRODUCT</td> 432 <td>A value chosen by the device implementer containing the development name 433 or code name of the product (SKU). MUST be human-readable, but is not necessarily 434 intended for view by end users. The value of this field MUST be encodable as 7-bit 435 ASCII and match the regular expression 436 <code>"^[a-zA-Z0-9.,_-]+$"</code>.</td> 437 </tr> 438 <tr> 439 <td>android.os.Build.SERIAL</td> 440 <td>A hardware serial number, if available. The value of this field MUST be encodable 441 as 7-bit ASCII and match the regular expression 442 <code>"^([a-zA-Z0-9]{0,20})$"</code>.</td> 443 </tr> 444 <tr> 445 <td>android.os.Build.TAGS</td> 446 <td>A comma-separated list of tags chosen by the device implementer that 447 further distinguish the build. For example, "unsigned,debug". The value of 448 this field MUST be encodable as 7-bit ASCII and match the regular expression 449 <code>"^[a-zA-Z0-9.,_-]+$"</code>.</td> 450 </tr> 451 <tr> 452 <td>android.os.Build.TIME</td> 453 <td>A value representing the timestamp of when the build occurred.</td> 454 </tr> 455 <tr> 456 <td>android.os.Build.TYPE</td> 457 <td>A value chosen by the device implementer specifying the runtime 458 configuration of the build. This field SHOULD have one of the values 459 corresponding to the three typical Android runtime configurations: "user", 460 "userdebug", or "eng". The value of this field MUST be 461 encodable as 7-bit ASCII and match the regular expression 462 <code>"^[a-zA-Z0-9.,_-]+$"</code>.</td> 463 </tr> 464 <tr> 465 <td>android.os.Build.USER</td> 466 <td>A name or user ID of the user (or automated user) that generated the 467 build. There are no requirements on the specific format of this field, except 468 that it MUST NOT be null or the empty string ("").</td> 469 </tr> 470 </tbody> 471 </table> 472 <a name="section-3.2.3"></a><h4>3.2.3. Intent Compatibility</h4> 473 <p> 474 Device implementations MUST honor Android's loose-coupling Intent system, as 475 described in the sections below. By "honored", it is meant that the device 476 implementer MUST provide an Android Activity or Service that specifies a 477 matching Intent filter and binds to and implements correct behavior for each 478 specified Intent pattern.</p> 479 <a name="section-3.2.3.1"></a><h4>3.2.3.1. Core Application Intents</h4> 480 <p>The Android upstream project defines a number of core applications, such as 481 contacts, calendar, photo gallery, music player, and so on. Device implementers 482 MAY replace these applications with alternative versions.</p> 483 <p>However, any such alternative versions MUST honor the same Intent patterns 484 provided by the upstream project. For example, if a device contains an 485 alternative music player, it must still honor the Intent pattern issued by 486 third-party applications to pick a song.</p> 487 <p>The following applications are considered core Android system 488 applications:</p> 489 <ul> 490 <li>Desk Clock</li> 491 <li>Browser</li> 492 <li>Calendar</li> 493 <li>Contacts</li> 494 <!--<li>Email</li>--> 495 <li>Gallery</li> 496 <li>GlobalSearch</li> 497 <li>Launcher</li> 498 <!-- <li>LivePicker (that is, the Live Wallpaper picker application; MAY be omitted 499 if the device does not support Live Wallpapers, per Section 3.8.5.)</li> --> 500 <!-- <li>Messaging (AKA "Mms")</li> --> 501 <li>Music</li> 502 <!-- <li>Phone</li> --> 503 <li>Settings</li> 504 <!-- <li>SoundRecorder</li> --> 505 </ul> 506 <p>The core Android system applications include various Activity, or Service 507 components that are considered "public". That is, the attribute 508 "android:exported" may be absent, or may have the value "true".</p> 509 <p>For every Activity or Service defined 510 in one of the core Android system apps that is not marked as non-public via an 511 android:exported attribute with the value "false", device implementations MUST 512 include a compontent of the same type implementing the same Intent filter 513 patterns as the core Android system app.</p> 514 <p>In other words, a device implementation MAY replace core Android system 515 apps; however, if it does, the device implementation MUST support all Intent 516 patterns defined by each core Android system app being replaced.</p> 517 <a name="section-3.2.3.2"></a><h4>3.2.3.2. Intent Overrides</h4> 518 <p>As Android is an extensible platform, device implementations MUST allow each 519 Intent pattern referenced in Section 3.2.3.2 to be overridden by third-party 520 applications. The upstream Android open source implementation allows this by 521 default; device implementers MUST NOT attach special privileges to system 522 applications' use of these Intent patterns, or prevent third-party 523 applications from binding to and assuming control of these patterns. This 524 prohibition specifically includes but is not limited to disabling the 525 "Chooser" user interface which allows the user to select between multiple 526 applications which all handle the same Intent pattern.</p> 527 <p>However, device implementations MAY provide default activities for specific 528 URI patterns (eg. http://play.google.com) if the default activity provides a 529 more specific filter for the data URI. For example, an intent filter specifying 530 the data URI "http://www.android.com" is more specific than the browser filter 531 for "http://". Device implementations MUST provide a user interface for users 532 to modify the default activity for intents.</p> 533 534 <a name="section-3.2.3.3"></a><h4>3.2.3.3. Intent Namespaces</h4> 535 <p>Device implementations MUST NOT include any Android component that honors any 536 new Intent or Broadcast Intent patterns using an ACTION, CATEGORY, or other 537 key string in the android.* or com.android.* namespace. Device implementers 538 MUST NOT include any Android components that honor any new Intent or Broadcast 539 Intent patterns using an ACTION, CATEGORY, or other key string in a package 540 space belonging to another organization. Device implementers MUST NOT alter or 541 extend any of the Intent patterns used by the core apps listed in Section 542 3.2.3.1. Device implementations MAY include Intent patterns using 543 namespaces clearly and obviously associated with their own organization.</p> 544 <p>This prohibition is analogous to that specified for Java language classes 545 in Section 3.6.</p> 546 <a name="section-3.2.3.4"></a><h4>3.2.3.4. Broadcast Intents</h4> 547 <p>Third-party applications rely on the platform to broadcast certain Intents 548 to notify them of changes in the hardware or software environment. 549 Android-compatible devices MUST broadcast the public broadcast Intents in 550 response to appropriate system events. Broadcast Intents are described in the 551 SDK documentation.</p> 552 553 <a name="section-3.3"></a><h3>3.3. Native API Compatibility</h3> 554 <a name="section-3.3.1"></a><h4>3.3.1 Application Binary Interfaces</h4> 555 <p>Managed code running in Dalvik can call into native code provided in the 556 application .apk file as an ELF .so file compiled for the appropriate device 557 hardware architecture. As native code is highly dependent on the underlying 558 processor technology, Android defines a number of Application Binary 559 Interfaces (ABIs) in the Android NDK, in the file 560 <code>docs/CPU-ARCH-ABIS.html</code>. If a device implementation is compatible 561 with one or more defined ABIs, it SHOULD implement compatibility with the 562 Android NDK, as below.</p> 563 <p>If a device implementation includes support for an Android ABI, it:</p> 564 <ul> 565 <li>MUST include support for code running in the managed environment to call 566 into native code, using the standard Java Native Interface (JNI) 567 semantics.</li> 568 <li>MUST be source-compatible (i.e. header compatible) and binary-compatible 569 (for the ABI) with each required library in the list below</li> 570 <li>MUST accurately report the native Application Binary Interface (ABI) 571 supported by the device, via the <code>android.os.Build.CPU_ABI</code> 572 API</li> 573 <li>MUST report only those ABIs documented in the latest version of the 574 Android NDK, in the file <code>docs/CPU-ARCH-ABIS.txt</code></li> 575 <li>SHOULD be built using the source code and header files available in the 576 upstream Android open source project</li> 577 </ul> 578 <p>The following native code APIs MUST be available to apps that include 579 native code:</p> 580 <ul> 581 <li>libc (C library)</li> 582 <li>libm (math library)</li> 583 <li>Minimal support for C++</li> 584 <li>JNI interface</li> 585 <li>liblog (Android logging)</li> 586 <li>libz (Zlib compression)</li> 587 <li>libdl (dynamic linker)</li> 588 <li>libGLESv1_CM.so (OpenGL ES 1.0)</li> 589 <li>libGLESv2.so (OpenGL ES 2.0)</li> 590 <li>libEGL.so (native OpenGL surface management)</li> 591 <li>libjnigraphics.so</li> 592 <li>libOpenSLES.so (OpenSL ES 1.0.1 audio support)</li> 593 <li>libOpenMAXAL.so (OpenMAX AL 1.0.1 support)</li> 594 <li>libandroid.so (native Android activity support)</li> 595 <li>Support for OpenGL, as described below</li> 596 </ul> 597 <p>Note that future releases of the Android NDK may introduce support for 598 additional ABIs. If a device implementation is not compatible with an existing 599 predefined ABI, it MUST NOT report support for any ABI at all.</p> 600 <p>Native code compatibility is challenging. For this reason, it should be 601 repeated that device implementers are VERY strongly encouraged to use the 602 upstream implementations of the libraries listed above to help ensure 603 compatibility.</p> 604 605 <a name="section-3.4"></a><h3>3.4. Web Compatibility</h3> 606 <a name="section-3.4.1"></a><h4>3.4.1. WebView Compatibility</h4> 607 <p>The Android Open Source implementation uses the WebKit rendering engine to 608 implement the <code>android.webkit.WebView</code>. Because it is not feasible 609 to develop a comprehensive test suite for a web rendering system, device 610 implementers MUST use the specific upstream build of WebKit in the WebView 611 implementation. Specifically:</p> 612 <ul> 613 <li>Device implementations' <code>android.webkit.WebView</code> 614 implementations MUST be based on the 534.30 WebKit build from the upstream 615 Android Open Source tree for Android 4.2. This build includes a specific set 616 of functionality and security fixes for the WebView. Device implementers MAY 617 include customizations to the WebKit implementation; however, any such 618 customizations MUST NOT alter the behavior of the WebView, including rendering 619 behavior.</li> 620 <li>The user agent string reported by the WebView MUST be in this format:<br/> 621 <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> 622 <ul> 623 <li>The value of the $(VERSION) string MUST be the same as the value for <code>android.os.Build.VERSION.RELEASE</code></li> 624 <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> 625 <li>The value of the $(MODEL) string MUST be the same as the value for <code>android.os.Build.MODEL</code></li> 626 <li>The value of the $(BUILD) string MUST be the same as the value for <code>android.os.Build.ID</code></li> 627 <li>Device implementations MAY omit <code>Mobile</code> in the user agent string</li> 628 </ul> 629 </li> 630 </ul> 631 <p>The WebView component SHOULD include support for as much of HTML5 [<a 632 href="#resources11">Resources, 11</a>] as possible. 633 Minimally, device implementations MUST support each of these APIs associated 634 with HTML5 in the WebView:</p> 635 <ul> 636 <li>application cache/offline operation [<a href="#resources12">Resources, 12</a>]</li> 637 <li>the <video> tag [<a href="#resources13">Resources, 13</a>]</li> 638 <li>geolocation [<a href="#resources14">Resources, 14</a>]</li> 639 </ul> 640 <p>Additionally, device implementations MUST support the HTML5/W3C webstorage 641 API [<a href="#resources15">Resources, 15</a>], and SHOULD support the 642 HTML5/W3C IndexedDB API [<a href="#resources16">Resources, 16</a>]. <i>Note 643 that as the web development standards bodies are transitioning to favor 644 IndexedDB over webstorage, IndexedDB is expected to become a required 645 component in a future version of Android.</i></p> 646 <p>HTML5 APIs, like all JavaScript APIs, MUST be disabled by default in a 647 WebView, unless the developer explicitly enables them via the usual Android 648 APIs.</p> 649 650 <a name="section-3.4.2"></a><h4>3.4.2. Browser Compatibility</h4> 651 <p>Device implementations MUST include a standalone Browser application for 652 general user web browsing. The standalone Browser MAY be based on a 653 browser technology other than WebKit. However, even if an alternate Browser 654 application is used, the <code>android.webkit.WebView</code> component 655 provided to third-party applications MUST be based on WebKit, as described in 656 Section 3.4.1.</p> 657 <p>Implementations MAY ship a custom user agent string in the standalone 658 Browser application.</p> 659 <p>The standalone Browser application (whether based on the upstream 660 WebKit Browser application or a third-party replacement) SHOULD include support 661 for as much of HTML5 [<a href="#resources11">Resources, 11</a>] as possible. 662 Minimally, device implementations MUST support each of these APIs associated 663 with HTML5:</p> 664 <ul> 665 <li>application cache/offline operation [<a href="#resources12">Resources, 12</a>]</li> 666 <li>the <video> tag [<a href="#resources13">Resources, 13</a>]</li> 667 <li>geolocation [<a href="#resources14">Resources, 14</a>]</li> 668 </ul> 669 <p>Additionally, device implementations MUST support the HTML5/W3C webstorage 670 API [<a href="#resources15">Resources, 15</a>], and SHOULD support the 671 HTML5/W3C IndexedDB API [<a href="#resources16">Resources, 16</a>]. <i>Note 672 that as the web development standards bodies are transitioning to favor 673 IndexedDB over webstorage, IndexedDB is expected to become a required 674 component in a future version of Android.</i></p> 675 676 <a name="section-3.5"></a><h3>3.5. API Behavioral Compatibility</h3> 677 <p>The behaviors of each of the API types (managed, soft, native, and web) 678 must be consistent with the preferred implementation of the upstream Android 679 open source project [<a href="#resources03">Resources, 3</a>]. Some specific areas 680 of compatibility are:</p> 681 <ul> 682 <li>Devices MUST NOT change the behavior or semantics of a standard Intent</li> 683 <li>Devices MUST NOT alter the lifecycle or lifecycle semantics of a 684 particular type of system component (such as Service, Activity, 685 ContentProvider, etc.)</li> 686 <li>Devices MUST NOT change the semantics of a standard permission</li> 687 </ul> 688 <p>The above list is not comprehensive. The Compatibility Test Suite (CTS) 689 tests significant portions of the platform for behavioral compatibility, but 690 not all. It is the responsibility of the implementer to ensure behavioral 691 compatibility with the Android Open Source Project. For this reason, device 692 implementers SHOULD use the source code available via the Android Open Source 693 Project where possible, rather than re-implement significant parts of the 694 system.</p> 695 696 697 <a name="section-3.6"></a><h3>3.6. API Namespaces</h3> 698 <p>Android follows the package and class namespace conventions defined by the 699 Java programming language. To ensure compatibility with third-party 700 applications, device implementers MUST NOT make any prohibited modifications 701 (see below) to these package namespaces:</p> 702 <ul> 703 <li>java.*</li> 704 <li>javax.*</li> 705 <li>sun.*</li> 706 <li>android.*</li> 707 <li>com.android.*</li> 708 </ul> 709 <p>Prohibited modifications include:</p> 710 <ul> 711 <li>Device implementations MUST NOT modify the publicly exposed APIs on the 712 Android platform by changing any method or class signatures, or by removing 713 classes or class fields.</li> 714 <li>Device implementers MAY modify the underlying implementation of the APIs, 715 but such modifications MUST NOT impact the stated behavior and Java-language 716 signature of any publicly exposed APIs.</li> 717 <li>Device implementers MUST NOT add any publicly exposed elements (such as 718 classes or interfaces, or fields or methods to existing classes or interfaces) 719 to the APIs above.</li> 720 </ul> 721 <p>A "publicly exposed element" is any construct which is not decorated with 722 the "@hide" marker as used in the upstream Android source code. In other 723 words, device implementers MUST NOT expose new APIs or alter existing APIs in 724 the namespaces noted above. Device implementers MAY make internal-only 725 modifications, but those modifications MUST NOT be advertised or otherwise 726 exposed to developers.</p> 727 <p>Device implementers MAY add custom APIs, but any such APIs MUST NOT be in a 728 namespace owned by or referring to another organization. For instance, device 729 implementers MUST NOT add APIs to the com.google.* or similar namespace; only 730 Google may do so. Similarly, Google MUST NOT add APIs to other companies' 731 namespaces. Additionally, if a device implementation includes custom APIs 732 outside the standard Android namespace, those APIs MUST be packaged in an 733 Android shared library so that only apps that explicitly use them (via the 734 <code><uses-library></code> mechanism) are affected by the increased 735 memory usage of such APIs.</p> 736 <p>If a device implementer proposes to improve one of the package namespaces 737 above (such as by adding useful new functionality to an existing API, or 738 adding a new API), the implementer SHOULD visit source.android.com and begin 739 the process for contributing changes and code, according to the information on 740 that site.</p> 741 <p>Note that the restrictions above correspond to standard conventions for 742 naming APIs in the Java programming language; this section simply aims to 743 reinforce those conventions and make them binding through inclusion in this 744 compatibility definition.</p> 745 746 <a name="section-3.7"></a><h3>3.7. Virtual Machine Compatibility</h3> 747 <p>Device implementations MUST support the full Dalvik Executable (DEX) 748 bytecode specification and Dalvik Virtual Machine semantics [<a 749 href="#resources17">Resources, 17</a>].</p> 750 <p>Device implementations MUST configure Dalvik to allocate memory in 751 accordance with the upstream Android platform, and as specified by the following 752 table. (See <a href="#section-7.1.1">Section 7.1.1</a> for screen size and screen 753 density definitions.)</p> 754 755 <p>Note that memory values specified below are considered minimum values, 756 and device implementations MAY allocate more memory per application.</p> 757 <table> 758 <tbody> 759 <tr> 760 <td><b>Screen Size</b></td> 761 <td><b>Screen Density</b></td> 762 <td><b>Application Memory</b></td> 763 </tr> 764 <tr> 765 <td>small / normal / large</td> 766 <td>ldpi / mdpi</td> 767 <td>16MB</td> 768 </tr> 769 <tr> 770 <td>small / normal / large</td> 771 <td>tvdpi / hdpi</td> 772 <td>32MB</td> 773 </tr> 774 <tr> 775 <td>small / normal / large</td> 776 <td>xhdpi</td> 777 <td>64MB</td> 778 </tr> 779 <tr> 780 <td>xlarge</td> 781 <td>mdpi</td> 782 <td>32MB</td> 783 </tr> 784 <tr> 785 <td>xlarge</td> 786 <td>tvdpi / hdpi</td> 787 <td>64MB</td> 788 </tr> 789 <tr> 790 <td>xlarge</td> 791 <td>xhdpi</td> 792 <td>128MB</td> 793 </tr> 794 </tbody> 795 </table> 796 797 <a name="section-3.8"></a><h3>3.8. User Interface Compatibility</h3> 798 <a name="section-3.8.1"></a><h4>3.8.1. Widgets</h4> 799 <p>Android defines a component type and corresponding API and lifecycle that 800 allows applications to expose an "AppWidget" to the end user [<a 801 href="#resources18">Resources, 18</a>]. 802 The Android Open Source reference release includes a Launcher application that 803 includes user interface affordances allowing the user to add, view, and remove 804 AppWidgets from the home screen.</p> 805 <p>Device implementations MAY substitute an alternative to the reference Launcher 806 (i.e. home screen). Alternative Launchers SHOULD include built-in support for 807 AppWidgets, and expose user interface affordances to add, configure, view, and 808 remove AppWidgets directly within the Launcher. Alternative Launchers MAY omit 809 these user interface elements; however, if they are omitted, the device 810 implementation MUST provide a separate application accessible from the Launcher 811 that allows users to add, configure, view, and remove AppWidgets.</p> 812 <p>Device implementations MUST be capable of rendering widgets that are 4 x 4 813 in the standard grid size. (See the App Widget Design Guidelines in the Android 814 SDK documentation [<a href="#resources18">Resources, 18</a>] for details.</p> 815 <p> 816 <a name="section-3.8.2"></a><h4>3.8.2. Notifications</h4> 817 <p>Android includes APIs that allow developers to notify users of notable 818 events [<a href="#resources19">Resources, 19</a>], using hardware and software 819 features of the device.</p> 820 <p>Some APIs allow applications to perform notifications or attract attention 821 using hardware, specifically sound, vibration, and light. Device implementations 822 MUST support notifications that use hardware features, as described in the SDK 823 documentation, and to the extent possible with the device implementation 824 hardware. For instance, if a device implementation includes a vibrator, it 825 MUST correctly implement the vibration APIs. If a device implementation lacks 826 hardware, the corresponding APIs MUST be implemented as no-ops. Note that this 827 behavior is further detailed in <a href="#section-7">Section 7.</a></p> 828 <p>Additionally, the implementation MUST correctly render all resources 829 (icons, sound files, etc.) provided for in the APIs [<a 830 href="#resources20">Resources, 20</a>], or in the 831 Status/System Bar icon style guide [<a href="#resources21">Resources, 21</a>]. 832 Device implementers MAY provide an alternative user experience for 833 notifications than that provided by the reference Android Open Source 834 implementation; however, such alternative notification systems MUST support 835 existing notification resources, as above.</p> 836 <p>Android 4.2 includes support for rich notifications, such as interactive 837 Views for ongoing notifications. Device implementations MUST properly display 838 and execute rich notifications, as documented in the Android APIs.</p> 839 <a name="section-3.8.3"></a><h4>3.8.3. Search</h4> 840 <p>Android includes APIs [<a href="#resources22">Resources, 22</a>] that allow 841 developers to incorporate search into their applications, and expose their 842 application's data into the global system search. Generally speaking, this 843 functionality consists of a single, system-wide user interface that allows users 844 to enter queries, displays suggestions as users type, and displays results. The 845 Android APIs allow developers to reuse this interface to provide search within 846 their own apps, and allow developers to supply results to the common global 847 search user interface.</p> 848 <p>Device implementations MUST include a single, shared, system-wide search 849 user interface capable of real-time suggestions in response to user input. 850 Device implementations MUST implement the APIs that allow developers to reuse 851 this user interface to provide search within their own applications. Device 852 implementations MUST implement the APIs that allow third-party applications to 853 add suggestions to the search box when it is run in global search mode. If no 854 third-party applications are installed that make use of this functionality, 855 the default behavior SHOULD be to display web search engine results and 856 suggestions.</p> 857 <a name="section-3.8.4"></a><h4>3.8.4. Toasts</h4> 858 <p>Applications can use the "Toast" API (defined in [<a 859 href="#resources23">Resources, 23</a>]) to 860 display short non-modal strings to the end user, that disappear after a brief 861 period of time. Device implementations MUST display Toasts from applications 862 to end users in some high-visibility manner.</p> 863 864 <a name="section-3.8.5"></a><h4>3.8.5. Themes</h4> 865 <p>Android provides "themes" as a mechanism for applications to apply styles 866 across an entire Activity or application. Android 4.2 includes a "Holo" 867 or "holographic" theme as a set of defined styles for application developers to 868 use if they want to match the Holo theme look and feel as defined by the Android 869 SDK [<a href="#resources24">Resources, 24</a>]. Device implementations MUST NOT 870 alter any of the Holo theme attributes exposed to applications 871 [<a href="#resources25">Resources, 25</a>].</p> 872 <p>Android 4.2 includes a new "Device Default" theme as a set of defined 873 styles for application developers to use if they want to match the look and feel 874 of the device theme as defined by the device implementer. Device implementations 875 MAY modify the DeviceDefault theme attributes exposed to applications 876 [<a href="#resources25">Resources, 25</a>].</p> 877 878 <a name="section-3.8.6"></a><h4>3.8.6. Live Wallpapers</h4> 879 <p>Android defines a component type and corresponding API and lifecycle that 880 allows applications to expose one or more "Live Wallpapers" to the end user 881 [<a href="#resources26">Resources, 26</a>]. Live Wallpapers are animations, 882 patterns, or similar images with limited input capabilities that display as a 883 wallpaper, behind other applications.</p> 884 <p>Hardware is considered capable of reliably running live wallpapers if it 885 can run all live wallpapers, with no limitations on functionality, at a 886 reasonable framerate with no adverse affects on other applications. If 887 limitations in the hardware cause wallpapers and/or applications to crash, 888 malfunction, consume excessive CPU or battery power, or run at unacceptably 889 low frame rates, the hardware is considered incapable of running live 890 wallpaper. As an example, some live wallpapers may use an Open GL 1.0 or 2.0 891 context to render their content. Live wallpaper will not run reliably on 892 hardware that does not support multiple OpenGL contexts because the live 893 wallpaper use of an OpenGL context may conflict with other applications that 894 also use an OpenGL context.</p> 895 <p>Device implementations capable of running live wallpapers reliably as 896 described above SHOULD implement live wallpapers. Device implementations 897 determined to not run live wallpapers reliably as described above MUST NOT 898 implement live wallpapers.</p> 899 <a name="section-3.8.7"></a><h4>3.8.7. Recent Application Display</h4> 900 <p>The upstream Android 4.2 source code includes a user interface for 901 displaying recent applications using a thumbnail image of the application's 902 graphical state at the moment the user last left the application. Device 903 implementations MAY alter or eliminate this user interface; however, a future 904 version of Android is planned to make more extensive use of this 905 functionality. Device implementations are strongly encouraged to use the 906 upstream Android 4.2 user interface (or a similar thumbnail-based interface) 907 for recent applications, or else they may not be compatible with a future 908 version of Android.</p> 909 <a name="section-3.8.8"></a><h4>3.8.8. Input Management Settings</h4> 910 <p>Android 4.2 includes support for Input Management Engines. The Android 4.2 911 APIs allow custom app IMEs to specify user-tunable settings. Device 912 implementations MUST include a way for the user to access IME settings at all 913 times when an IME that provides such user settings is displayed.</p> 914 915 <a name="section-3.8.9"></a><h4>3.8.9. Lock and Home Screen Widgets</h4> 916 <p>Android 4.2 includes support for application widgets that users can embed in the home screen or the lock screen 917 (See the App Widget Design Guidelines in the Android SDK documentation [<a href="#resources69">Resources, 69</a>] for details). 918 Application widgets allow quick access to application data and services without launching a new activity. Widgets declare support 919 for usage on the home screen or the lock screen by declaring the <code>android:widgetCategory</code> manifest tag that tells the system 920 where the widget can be placed. Specifically, device implementations MUST meet the following requirements.</p> 921 <ul> 922 <li>Device implementations MUST support application widgets on the home screen.</li> 923 <li>Device implementations SHOULD support lock screen. If device implementations include support for lock screen 924 then device implementations MUST support application widgets on the lock screen.</li> 925 </ul> 926 927 <a name="section-3.8.10"></a><h4>3.8.10. Lock Screen Media Remote Control</h4> 928 <p>Android 4.2 includes support for Remote Control API that lets media applications integrate with playback controls 929 that are displayed in a remote view like the device lock screen[<a href="#resources74">Resources, 74</a>]. Device implementations MUST 930 include support for embedding remote controls in the device lock screen. 931 </p> 932 <a name="section-3.8.11"></a><h4>3.8.11. Dreams</h4> 933 <p>Android 4.2 includes support for interactive screensavers called Dreams [<a href="#resources76">Resources, 76</a>]. 934 Dreams allows users to interact with applications when a charging device is idle, or docked in a desk dock. Device implementations 935 MUST include support for Dreams and provide a settings option for users to configure Dreams.</p> 936 937 <a name="section-3.9"></a><h3>3.9 Device Administration</h3> 938 <p>Android 4.2 includes features that allow security-aware applications 939 to perform device administration functions at the system level, such as enforcing 940 password policies or performing remote wipe, through the Android Device 941 Administration API [<a href="#resources27">Resources, 27</a>]. Device 942 implementations MUST provide an implementation of the <code>DevicePolicyManager 943 </code> class [<a href="#resources28">Resources, 28</a>], and SHOULD support 944 the full range of device administration policies defined in the Android SDK 945 documentation [<a href="#resources27">Resources, 27</a>]. 946 </p> 947 <p><b>Note:</b> while some of the requirements outlined above are stated as "SHOULD" 948 for Android 4.2, device implementations that support lock screen MUST support device policies to manage widgets 949 on the lock screen as defined in the Android SDK 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, the Compatibility Definition for a future version is planned 953 to change these to "MUST". That is, these requirements are optional in Android 954 4.2 but <b>will be required</b> by a future version. Existing and new devices 955 that run Android 4.2 are <b>very strongly encouraged to meet 956 these requirements in Android 4.2</b>, or they will not be able to attain 957 Android compatibility when upgraded to the future version.</p> 958 959 <a name="section-3.10"></a><h3>3.10 Accessibility</h3> 960 <p>Android 4.2 provides an accessibility layer that helps users with disabilities 961 to navigate their devices more easily. In addition, Android 4.2 provides 962 platform APIs that enable accessibility service implementations to receive 963 callbacks for user and system events and generate alternate feedback mechanisms, 964 such as text-to-speech, haptic feedback, and trackball/d-pad navigation 965 [<a href="#resources29">Resources, 29</a>]. Device implementations MUST provide an 966 implementation of the Android accessibility framework consistent with the 967 default Android implementation. Specifically, device implementations MUST meet 968 the following requirements.</p> 969 <ul> 970 <li>Device implementations MUST support third party accessibility service 971 implementations through the <code>android.accessibilityservice</code> 972 APIs [<a href="#resources30">Resources, 30</a>].</li> 973 <li>Device implementations MUST generate <code>AccessibilityEvents</code> 974 and deliver these events to all registered <code>AccessibilityService 975 </code> implementations in a manner consistent with the default Android 976 implementation.</li> 977 <li>Device implementations MUST provide a user-accessible mechanism to enable 978 and disable accessibility services, and MUST display this interface in 979 response to the 980 <code>android.provider.Settings.ACTION_ACCESSIBILITY_SETTINGS</code> 981 intent.</li> 982 </ul> 983 <p>Additionally, device implementations SHOULD provide an implementation 984 of an accessibility service on the device, and SHOULD provide a mechanism 985 for users to enable the accessibility service during device setup. An open 986 source implementation of an accessibility service is available from the Eyes 987 Free project [<a href="#resources31">Resources, 31</a>].</p> 988 989 <a name="section-3.11"></a><h3>3.11 Text-to-Speech</h3> 990 <p>Android 4.2 includes APIs that allow applications to make use of 991 text-to-speech (TTS) services, and allows service providers to provide 992 implementations of TTS services [<a href="#resources32">Resources, 32</a>]. 993 Device implementations MUST meet these requirements related to the Android TTS 994 framework:</p> 995 <ul> 996 <li>Device implementations MUST support the Android TTS framework APIs and 997 SHOULD include a TTS engine supporting the languages available on the 998 device. Note that the upstream Android open source software includes a 999 full-featured TTS engine implementation.</li> 1000 <li>Device implementations MUST support installation of third-party TTS 1001 engines.</li> 1002 <li>Device implementations MUST provide a user-accessible interface that allows 1003 users to select a TTS engine for use at the system level.</li> 1004 </ul> 1005 1006 <a name="section-4"></a><h2>4. Application Packaging Compatibility</h2> 1007 <p>Device implementations MUST install and run Android ".apk" files as 1008 generated by the "aapt" tool included in the official Android SDK [<a 1009 href="#resources33">Resources, 33</a>].</p> 1010 <p>Devices implementations MUST NOT extend either the .apk [<a 1011 href="#resources34">Resources, 34</a>], Android Manifest [<a 1012 href="#resources35">Resources, 35</a>], 1013 Dalvik bytecode [<a href="#resources17">Resources, 17</a>], or renderscript 1014 bytecode formats in such a way that would prevent those files from installing 1015 and running correctly on other compatible devices. Device implementers SHOULD 1016 use the reference upstream implementation of Dalvik, and the reference 1017 implementation's package management system.</p> 1018 1019 <a name="section-5"></a><h2>5. Multimedia Compatibility</h2> 1020 <p>Device implementations MUST include at least one form of audio output, such as 1021 speakers, headphone jack, external speaker connection, etc.</p> 1022 <a name="section-5.1"></a><h3>5.1. Media Codecs</h3> 1023 <p>Device implementations MUST support the core media formats specified 1024 in the Android SDK documentation [<a href="#resources58">Resources, 58</a>] except 1025 where explicitly permitted in this document. Specifically, device implementations 1026 MUST support the media formats, encoders, decoders, file types and container 1027 formats defined in the tables below. All of these codecs are provided as 1028 software implementations in the preferred Android implementation from the Android 1029 Open Source Project.</p> 1030 1031 <p><strong>Please note that neither Google nor the Open Handset Alliance make any 1032 representation that these codecs are unencumbered by third-party patents. 1033 Those intending to use this source code in hardware or software products are 1034 advised that implementations of this code, including in open source software 1035 or shareware, may require patent licenses from the relevant patent 1036 holders.</strong></p> 1037 1038 <p>Note that these tables do not list specific bitrate requirements for 1039 most video codecs because current device hardware does not necessarily support 1040 bitrates that map exactly to the required bitrates specified by the relevant 1041 standards. Instead, device implementations SHOULD support the highest bitrate 1042 practical on the hardware, up to the limits defined by the specifications.</p> 1043 <div style="page-break-before: always;"></div> 1044 <table> 1045 <tbody> 1046 1047 <tr> 1048 <th>Type</th> 1049 <th>Format / Codec</th> 1050 <th>Encoder</th> 1051 <th>Decoder</th> 1052 <th>Details</th> 1053 <th>File Type(s) / Container Formats</th> 1054 </tr> 1055 1056 <tr> 1057 <td rowspan="11">Audio</td> 1058 <td>MPEG-4 AAC Profile (AAC LC)</td> 1059 <td style="text-align: center;">REQUIRED<br/> 1060 <small>Required for device implementations that include microphone hardware 1061 and define <code>android.hardware.microphone</code>.</small></td> 1062 <td style="text-align: center;">REQUIRED</td> 1063 <td rowspan="1"> Support for mono/stereo/5.0/5.1* content with standard sampling rates from 8 to 48 kHz.</td> 1064 <td rowspan="4"> 1065 <ul> 1066 <li>3GPP (.3gp)</li> 1067 <li>MPEG-4 (.mp4, .m4a)</li> 1068 <li>ADTS raw AAC (.aac, decode in Android 3.1+, encode in Android 4.0+, ADIF not supported)</li> 1069 <li>MPEG-TS (.ts, not seekable, Android 3.0+)</li> 1070 </ul> 1071 </td> 1072 </tr> 1073 1074 <tr> 1075 <td>MPEG-4 HE AAC Profile (AAC+)</td> 1076 <td>REQUIRED for device implementations that include microphone hardware and define android.hardware.microphone</td> 1077 <td style="text-align: center;">REQUIRED</td> 1078 <td>Support for mono/stereo/5.0/5.1* content with standard sampling rates from 16 to 48 kHz.</td> 1079 </tr> 1080 1081 <tr> 1082 <td>MPEG-4 HE AAC v2 Profile (enhanced AAC+)</td> 1083 <td> </td> 1084 <td style="text-align: center;">REQUIRED</td> 1085 <td>Support for mono/stereo/5.0/5.1* content with standard sampling rates from 16 to 48 kHz.</td> 1086 </tr> 1087 1088 <tr> 1089 <td>MPEG-4 Audio Object Type ER AAC ELD (Enhanced Low Delay AAC)</td> 1090 <td>REQUIRED for device implementations that include microphone hardware and define android.hardware.microphone</td> 1091 <td style="text-align: center;">REQUIRED</td> 1092 <td>Support for mono/stereo content with standard 1093 sampling rates from 16 to 48 kHz.</td> 1094 </tr> 1095 1096 <tr> 1097 <td>AMR-NB</td> 1098 <td style="text-align: center;">REQUIRED<br/> 1099 <small>Required for device implementations that include microphone hardware 1100 and define <code>android.hardware.microphone</code>.</small></td> 1101 <td style="text-align: center;">REQUIRED</td> 1102 <td>4.75 to 12.2 kbps sampled @ 8kHz</td> 1103 <td>3GPP (.3gp) 1104 </td> 1105 </tr> 1106 1107 <tr> 1108 <td>AMR-WB</td> 1109 <td style="text-align: center;">REQUIRED<br/> 1110 <small>Required for device implementations that include microphone hardware 1111 and define <code>android.hardware.microphone</code>.</small></td> 1112 <td style="text-align: center;">REQUIRED</td> 1113 <td>9 rates from 6.60 kbit/s to 23.85 kbit/s sampled @ 16kHz</td> 1114 <td>3GPP (.3gp)</td> 1115 </tr> 1116 1117 <tr> 1118 <td>FLAC</td> 1119 <td> </td> 1120 <td style="text-align: center;">REQUIRED<br/><small>(Android 3.1+)</small></td> 1121 <td>Mono/Stereo (no multichannel). Sample rates up to 48 kHz (but up to 44.1 1122 kHz is recommended on devices with 44.1 kHz output, as the 48 to 44.1 kHz 1123 downsampler does not include a low-pass filter). 16-bit recommended; 1124 no dither applied for 24-bit. 1125 </td> 1126 <td>FLAC (.flac) only</td> 1127 </tr> 1128 1129 <tr> 1130 <td>MP3</td> 1131 <td> </td> 1132 <td style="text-align: center;">REQUIRED</td> 1133 <td>Mono/Stereo 8-320Kbps constant (CBR) or variable bit-rate (VBR) 1134 </td> 1135 <td>MP3 (.mp3)</td> 1136 </tr> 1137 1138 <tr> 1139 <td>MIDI</td> 1140 <td> </td> 1141 <td style="text-align: center;">REQUIRED</td> 1142 <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> 1143 <td> 1144 <ul> 1145 <li>Type 0 and 1 (.mid, .xmf, .mxmf)</li> 1146 <li>RTTTL/RTX (.rtttl, .rtx)</li> 1147 <li>OTA (.ota)</li> 1148 <li>iMelody (.imy)</li> 1149 </ul> 1150 </td> 1151 </tr> 1152 1153 <tr> 1154 <td>Vorbis</td> 1155 <td> </td> 1156 <td style="text-align: center;">REQUIRED</td> 1157 <td> </td> 1158 <td> 1159 <ul> 1160 <li>Ogg (.ogg)</li> 1161 <li>Matroska (.mkv)</li> 1162 </ul> 1163 </td> 1164 </tr> 1165 1166 <tr> 1167 <td>PCM/WAVE</td> 1168 <td style="text-align: center;">REQUIRED</td> 1169 <td style="text-align: center;">REQUIRED</td> 1170 <td>8-bit and 16-bit linear PCM** (rates up to limit of hardware).Devices MUST support sampling rates 1171 for raw PCM recording at 8000,16000 and 44100 Hz frequencies</td> 1172 <td>WAVE (.wav)</td> 1173 </tr> 1174 1175 <tr> 1176 <td rowspan="5">Image</td> 1177 <td>JPEG</td> 1178 <td style="text-align: center;">REQUIRED</td> 1179 <td style="text-align: center;">REQUIRED</td> 1180 <td>Base+progressive</td> 1181 <td>JPEG (.jpg)</td> 1182 </tr> 1183 1184 <tr> 1185 <td>GIF</td> 1186 <td> </td> 1187 <td style="text-align: center;">REQUIRED</td> 1188 <td> </td> 1189 <td>GIF (.gif)</td> 1190 </tr> 1191 1192 <tr> 1193 <td>PNG</td> 1194 <td style="text-align: center;">REQUIRED</td> 1195 <td style="text-align: center;">REQUIRED</td> 1196 <td> </td> 1197 <td>PNG (.png)</td> 1198 </tr> 1199 1200 <tr> 1201 <td>BMP</td> 1202 <td> </td> 1203 <td style="text-align: center;">REQUIRED</td> 1204 <td> </td> 1205 <td>BMP (.bmp)</td> 1206 </tr> 1207 1208 1209 <tr> 1210 <td>WEBP</td> 1211 <td style="text-align: center;">REQUIRED</td> 1212 <td style="text-align: center;">REQUIRED</td> 1213 <td> </td> 1214 <td>WebP (.webp)</td> 1215 </tr> 1216 1217 <tr> 1218 <td rowspan="4">Video</td> 1219 <td>H.263</td> 1220 <td style="text-align: center;">REQUIRED<br/> 1221 <small>Required for device implementations that include camera hardware 1222 and define <code>android.hardware.camera</code> or 1223 <code>android.hardware.camera.front</code>.</small></td> 1224 <td style="text-align: center;">REQUIRED</td> 1225 <td> </td> 1226 <td> 1227 <ul> 1228 <li>3GPP (.3gp)</li> 1229 <li>MPEG-4 (.mp4)</li> 1230 </ul> 1231 </td> 1232 </tr> 1233 1234 <tr> 1235 <td>H.264 AVC</td> 1236 <td style="text-align: center;">REQUIRED<br/> 1237 <small>Required for device implementations that include camera hardware 1238 and define <code>android.hardware.camera</code> or 1239 <code>android.hardware.camera.front</code>.</small></td> 1240 <td style="text-align: center;">REQUIRED</td> 1241 <td>Baseline Profile (BP)</td> 1242 <td> 1243 <ul> 1244 <li>3GPP (.3gp)</li> 1245 <li>MPEG-4 (.mp4)</li> 1246 <li>MPEG-TS (.ts, AAC audio only, not seekable, Android 3.0+)</li> 1247 </ul> 1248 </td> 1249 </tr> 1250 1251 <tr> 1252 <td>MPEG-4 SP</td> 1253 <td> </td> 1254 <td style="text-align: center;">REQUIRED</td> 1255 <td> </td> 1256 <td>3GPP (.3gp)</td> 1257 </tr> 1258 1259 <tr> 1260 <td>VP8</td> 1261 <td> </td> 1262 <td style="text-align: center;">REQUIRED<br/><small>(Android 2.3.3+)</small></td> 1263 <td> </td> 1264 <td><a href="http://www.webmproject.org/">WebM</a> (.webm) and Matroska (.mkv, Android 4.0+)</td> 1265 </tr> 1266 1267 </tbody></table> 1268 *Note: Only downmix of 5.0/5.1 content is required; recording or rendering more than 2 channels is optional. 1269 **Note: 16-bit linear PCM capture is mandatory. 8-bit linear PCM capture is not mandatory. 1270 1271 <a name="section-5.2"></a><h3>5.2 Video Encoding</h3> 1272 <p>Android device implementations that include a rear-facing camera and declare 1273 <code>android.hardware.camera</code> SHOULD support the following video encoding 1274 profiles.</p> 1275 <table> 1276 <thead> 1277 <tr> 1278 <th> </th> 1279 <th>SD (Low quality)</th> 1280 <th>SD (High quality)</th> 1281 <th>HD (When supported by hardware)</th> 1282 </tr> 1283 </thead> 1284 <tbody> 1285 <tr> 1286 <th>Video codec</th> 1287 <td>H.264 Baseline Profile</td> 1288 <td>H.264 Baseline Profile</td> 1289 <td>H.264 Baseline Profile</td> 1290 </tr> 1291 <tr> 1292 <th>Video resolution</th> 1293 <td>176 x 144 px</td> 1294 <td>480 x 360 px</td> 1295 <td>1280 x 720 px</td> 1296 </tr> 1297 <tr> 1298 <th>Video frame rate</th> 1299 <td>12 fps</td> 1300 <td>30 fps</td> 1301 <td>30 fps</td> 1302 </tr> 1303 <tr> 1304 <th>Video bitrate</th> 1305 <td>56 Kbps</td> 1306 <td>500 Kbps or higher</td> 1307 <td>2 Mbps or higher</td> 1308 </tr> 1309 <tr> 1310 <th>Audio codec</th> 1311 <td>AAC-LC</td> 1312 <td>AAC-LC</td> 1313 <td>AAC-LC</td> 1314 </tr> 1315 <tr> 1316 <th>Audio channels</th> 1317 <td>1 (mono)</td> 1318 <td>2 (stereo)</td> 1319 <td>2 (stereo)</td> 1320 </tr> 1321 <tr> 1322 <th>Audio bitrate</th> 1323 <td>24 Kbps</td> 1324 <td>128 Kbps</td> 1325 <td>192 Kbps</td> 1326 </tr> 1327 </tbody> 1328 </table> 1329 1330 <a name="section-5.3"></a><h3>5.3 Video Decoding</h3> 1331 <p>Android device implementations SHOULD support the following VP8 video decoding profiles.</p> 1332 <div style="page-break-before: always;"></div> 1333 <table> 1334 <thead> 1335 <tr> 1336 <th> </th> 1337 <th>SD (Low quality)</th> 1338 <th>SD (High quality)</th> 1339 <th>HD 720p <br/> (When supported by hardware)</th> 1340 <th>HD 1080p <br/>(When supported by hardware)</th> 1341 </tr> 1342 </thead> 1343 <tbody> 1344 <tr> 1345 <th>Video resolution</th> 1346 <td>320 x 180 px</td> 1347 <td>640 x 360 px</td> 1348 <td>1280 x 720 px</td> 1349 <td>1920 x 1080 px</td> 1350 </tr> 1351 <tr> 1352 <th>Video frame rate</th> 1353 <td>30 fps</td> 1354 <td>30 fps</td> 1355 <td>30 fps</td> 1356 <td>30 fps</td> 1357 </tr> 1358 <tr> 1359 <th>Video bitrate</th> 1360 <td>800 Kbps</td> 1361 <td>2 Mbps</td> 1362 <td>8 Mbps</td> 1363 <td>20 Mbps</td> 1364 </tr> 1365 </tbody> 1366 </table> 1367 <a name="section-5.4"></a><h3>5.4. Audio Recording</h3> 1368 <p>When an application has used the <code>android.media.AudioRecord</code> API to 1369 start recording an audio stream, device implementations that include microphone 1370 hardware and declare <code>android.hardware.microphone</code> MUST sample and 1371 record audio with each of these behaviors:</p> 1372 <ul> 1373 <li>The device SHOULD exhibit approximately flat amplitude versus frequency 1374 characteristics; specifically, ±3 dB, from 100 Hz to 4000 Hz</li> 1375 <li>Audio input sensitivity SHOULD be set such that a 90 dB sound power level 1376 (SPL) source at 1000 Hz yields RMS of 2500 for 16-bit samples.</li> 1377 <li>PCM amplitude levels SHOULD linearly track input SPL changes over at least 1378 a 30 dB range from -18 dB to +12 dB re 90 dB SPL at the microphone.</li> 1379 <li>Total harmonic distortion SHOULD be less than 1% for 1Khz at 90 dB SPL input level.</li> 1380 </ul> 1381 <p>In addition to the above recording specifications, when an application has 1382 started recording an audio stream using the 1383 <code>android.media.MediaRecorder.AudioSource.VOICE_RECOGNITION</code> audio 1384 source:</p> 1385 <ul> 1386 <li>Noise reduction processing, if present, MUST be disabled.</li> 1387 <li>Automatic gain control, if present, MUST be disabled.</li> 1388 </ul> 1389 <p><b>Note:</b> while some of the requirements outlined above are stated as "SHOULD" 1390 for Android 4.2, the Compatibility Definition for a future version is planned 1391 to change these to "MUST". That is, these requirements are optional in Android 1392 4.2 but <b>will be required</b> by a future version. Existing and new devices 1393 that run Android 4.2 are <b>very strongly encouraged to meet 1394 these requirements in Android 4.2</b>, or they will not be able to attain 1395 Android compatibility when upgraded to the future version.</p> 1396 1397 <a name="section-5.5"></a><h3>5.5. Audio Latency</h3> 1398 <p>Audio latency is the time delay as an audio signal passes through a system. 1399 Many classes of 1400 applications rely on short latencies, to achieve real-time effects such sound 1401 effects or VOIP communication.</p> 1402 <p>For the purposes of this section:</p> 1403 <ul> 1404 <li>"output latency" is defined as the interval between when an application 1405 writes a frame of PCM-coded data and when the corresponding sound can be heard 1406 by an external listener or observed by a transducer</li> 1407 <li>"cold output latency" is defined as the output latency for the first frame, when 1408 the audio output system has been idle and powered down prior to the request</li> 1409 <li>"continuous output latency" is defined as the output latency for subsequent frames, 1410 after the device is already playing audio</li> 1411 <li>"input latency" is the interval between when an external sound is presented 1412 to the device and when an application reads the corresponding frame of PCM-coded data</li> 1413 <li>"cold input latency" is defined as the sum of lost input time 1414 and the input latency for the first frame, when 1415 the audio input system has been idle and powered down prior to the request</li> 1416 <li>"continuous input latency" is defined as the input latency for subsequent frames, 1417 while the device is already capturing audio</li> 1418 <li>"OpenSL ES PCM buffer queue API" is the set of PCM-related OpenSL ES APIs within Android NDK; 1419 see <i>NDK_root</i><code>/docs/opensles/index.html</code></li> 1420 </ul> 1421 <p>Per <a href="#section-5">Section 5</a>, 1422 all compatible device implementations MUST include at least one form of audio output. 1423 Device implementations SHOULD meet or exceed these output latency requirements:</p> 1424 <ul> 1425 <li>cold output latency of 100 milliseconds or less</li> 1426 <li>continuous output latency of 45 milliseconds or less</li> 1427 </ul> 1428 <p>If a device implementation meets the requirements of this section 1429 after any initial calibration 1430 when using the OpenSL ES PCM buffer queue API, 1431 for continuous output latency and cold output latency 1432 over at least one supported audio output device, it MAY 1433 report support for low-latency audio, by reporting the feature 1434 "android.hardware.audio.low-latency" via the 1435 <code>android.content.pm.PackageManager</code> class. [<a 1436 href="#resources37">Resources, 37</a>] Conversely, if the device 1437 implementation does not meet these requirements it MUST NOT report support for 1438 low-latency audio.</p> 1439 <p> 1440 Per <a href="#section-7.2.5">Section 7.2.5</a>, 1441 microphone hardware may be omitted by device implementations.</p> 1442 <p> 1443 Device implementations that include microphone 1444 hardware and declare <code>android.hardware.microphone</code> SHOULD 1445 meet these input audio latency requirements:</p> 1446 <ul> 1447 <li>cold input latency of 100 milliseconds or less</li> 1448 <li>continuous input latency of 50 milliseconds or less</li> 1449 </ul> 1450 1451 <a name="section-5.6"></a><h3>5.6. Network Protocols</h3> 1452 <p>Devices MUST support the media network protocols for audio and video playback 1453 as specified in the Android SDK documentation 1454 [<a href="#resources58">Resources, 58</a>]. Specifically, devices MUST support 1455 the following media network protocols:</p> 1456 <ul> 1457 <li>RTSP (RTP, SDP)</li> 1458 <li>HTTP(S) progressive streaming</li> 1459 <li>HTTP(S) Live Streaming draft protocol, Version 3 [<a href="#resources59">Resources, 59</a>]</li> 1460 </ul> 1461 <a name="section-6"></a><h2>6. Developer Tools and Options Compatibility</h2> 1462 1463 <a name="section-6.1"></a><h3>6.1 Developer Tools</h3> 1464 <p>Device implementations MUST support the Android Developer Tools provided in the Android SDK. 1465 Specifically, Android-compatible devices MUST be compatible with:</p> 1466 <ul> 1467 <li><b>Android Debug Bridge (known as adb)</b> [<a href="#resources33">Resources, 33</a>]<br/> 1468 Device implementations MUST support all <code>adb</code> functions as 1469 documented in the Android SDK. The device-side <code>adb</code> daemon MUST 1470 be inactive by default, and there MUST be a user-accessible mechanism to turn 1471 on the Android Debug Bridge.</li> 1472 <p>Android 4.2.2 includes support for secure adb. Secure adb enables adb on known authenticated hosts. 1473 Existing and new devices that run Android 4.2.2 are <b>very strongly encouraged to meet 1474 this requirement in Android 4.2</b>, or they will not be able to attain 1475 Android compatibility when upgraded to the future version.</p> 1476 <li><b>Dalvik Debug Monitor Service (known as ddms)</b> [<a href="#resources33">Resources, 33</a>]<br/> 1477 Device implementations MUST support all <code>ddms</code> features as documented in the 1478 Android SDK. As <code>ddms</code> uses <code>adb</code>, support for 1479 <code>ddms</code> SHOULD be inactive by default, 1480 but MUST be supported whenever the user has activated the Android Debug 1481 Bridge, as above.</li> 1482 <li><b>Monkey</b> [<a href="#resources36">Resources, 36</a>]<br/> 1483 Device implementations MUST include the Monkey framework, and make it 1484 available for applications to use.</li> 1485 <li><b>SysTrace</b> [<a href="#resources33">Resources, 33</a>]<br/> 1486 Device implementations MUST support systrace tool as documented in the Android SDK. 1487 Systrace must be inactive by default, and there MUST be a user-accessible mechanism to turn 1488 on Systrace.</li> 1489 </ul> 1490 <p>Most Linux-based systems and Apple Macintosh systems recognize Android 1491 devices using the standard Android SDK tools, without additional support; 1492 however Microsoft Windows systems typically require a driver for new Android 1493 devices. (For instance, new vendor IDs and sometimes new device IDs require 1494 custom USB drivers for Windows systems.) If a device implementation is 1495 unrecognized by the <code>adb</code> tool as provided in the standard Android 1496 SDK, device implementers MUST provide Windows drivers allowing developers to 1497 connect to the device using the <code>adb</code> protocol. These drivers MUST 1498 be provided for Windows XP, Windows Vista, Windows 7, and Windows 8, in both 32-bit and 1499 64-bit versions.</p> 1500 1501 <a name="section-6.2"></a><h3>6.2 Developer Options</h3> 1502 <p>Android 4.2 includes support for developers to configure application development-related settings. 1503 Device implementations MUST honor the android.settings.APPLICATION_DEVELOPMENT_SETTINGS intent to show 1504 application development-related settings [<a href="#resources77">Resources, 77</a>]. The upstream Android 1505 implementation hides the Developer Options menu by default, and enables users to launch Developer Options 1506 after pressing seven (7) times on the Settings > About Device > Build Number menu item. Device implementations 1507 MUST provide a consistent experience for Developer Options. Specifically, device implementations MUST hide 1508 Developer Options by default and MUST provide a mechanism to enable Developer Options that is consistent with 1509 the upstream Android implementation.</p> 1510 1511 <a name="section-7"></a><h2>7. Hardware Compatibility</h2> 1512 <p>If a device includes a particular hardware component that has a 1513 corresponding API for third-party developers, the device implementation MUST 1514 implement that API as described in the Android SDK documentation. If an API in 1515 the SDK interacts with a hardware component that is stated to be optional and 1516 the device implementation does not possess that component:</p> 1517 <ul> 1518 <li>complete class definitions (as documented by the SDK) for the component's 1519 APIs MUST still be present</li> 1520 <li>the API's behaviors MUST be implemented as no-ops in some reasonable 1521 fashion</li> 1522 <li>API methods MUST return null values where permitted by the SDK 1523 documentation</li> 1524 <li>API methods MUST return no-op implementations of classes where null 1525 values are not permitted by the SDK documentation</li> 1526 <li>API methods MUST NOT throw exceptions not documented by the SDK 1527 documentation</li> 1528 </ul> 1529 <p>A typical example of a scenario where these requirements apply is the 1530 telephony API: even on non-phone devices, these APIs must be implemented as 1531 reasonable no-ops.</p> 1532 <p>Device implementations MUST accurately report accurate hardware configuration 1533 information via the <code>getSystemAvailableFeatures()</code> and 1534 <code>hasSystemFeature(String)</code> methods on the 1535 <code>android.content.pm.PackageManager</code> class. [<a 1536 href="#resources37">Resources, 37</a>]</p> 1537 1538 <a name="section-7.1"></a><h3>7.1. Display and Graphics</h3> 1539 <p>Android 4.2 includes facilities that automatically adjust application 1540 assets and UI layouts appropriately for the device, to ensure that third-party 1541 applications run well on a variety of hardware configurations [<a 1542 href="#resources38">Resources, 38</a>]. Devices MUST properly implement these 1543 APIs and behaviors, as detailed in this section.</p> 1544 1545 <p>The units referenced by the requirements in this section are defined as follows:</p> 1546 <ul> 1547 <li>"Physical diagonal size" is the distance in inches between two opposing 1548 corners of the illuminated portion of the display.</li> 1549 <li>"dpi" (meaning "dots per inch") is the number of pixels encompassed by a 1550 linear horizontal or vertical span of 1". Where dpi values are listed, both 1551 horizontal and vertical dpi must fall within the range.</li> 1552 <li>"Aspect ratio" is the ratio of the longer dimension of the screen to the 1553 shorter dimension. For example, a display of 480x854 pixels would be 854 / 480 1554 = 1.779, or roughly "16:9".</li> 1555 <li>A "density-independent pixel" or ("dp") is the virtual pixel unit normalized to a 1556 160 dpi screen, calculated as: 1557 <code>pixels = dps * (density / 160)</code>.</li> 1558 </ul> 1559 1560 1561 <a name="section-7.1.1"></a><h4>7.1.1. Screen Configuration</h4> 1562 1563 <p style="font-weight:bold;">Screen Size</p> 1564 <p>The Android UI framework supports a variety of different screen sizes, and 1565 allows applications to query the device screen size (aka "screen layout") via 1566 <code>android.content.res.Configuration.screenLayout</code> with the 1567 <code>SCREENLAYOUT_SIZE_MASK</code>. Device implementations MUST report the 1568 correct screen size as defined in the Android SDK documentation 1569 [<a href="#resources38">Resources, 38</a>] and determined by the upstream 1570 Android platform. Specifically, device implementations must report the correct 1571 screen size according to the following logical density-independent pixel (dp) 1572 screen dimensions.</p> 1573 <ul> 1574 <li>Devices MUST have screen sizes of at least 426 dp x 320 dp ('small')</li> 1575 <li>Devices that report screen size 'normal' MUST have screen sizes of at least 1576 480 dp x 320 dp</li> 1577 <li>Devices that report screen size 'large' MUST have screen sizes of at least 1578 640 dp x 480 dp</li> 1579 <li>Devices that report screen size 'xlarge' MUST have screen sizes of at least 1580 960 dp x 720 dp</li> 1581 </ul> 1582 <p>In addition, devices MUST have screen sizes of at least 2.5 inches in 1583 physical diagonal size.</p> 1584 1585 <p>Devices MUST NOT change their reported screen size at any time.</p> 1586 <p>Applications optionally indicate which screen sizes they support via the 1587 <code><supports-screens></code> attribute in the AndroidManifest.xml 1588 file. Device implementations MUST correctly honor applications' stated support 1589 for small, normal, large, and xlarge screens, as described in the Android 1590 SDK documentation.</p> 1591 1592 <p style="font-weight:bold;">Screen Aspect Ratio</p> 1593 <p>The aspect ratio MUST be between 1.3333 (4:3) and 1.85 (16:9).</p> 1594 1595 <p style="font-weight:bold;">Screen Density</p> 1596 <p>The Android UI framework defines a set of standard logical densities to 1597 help application developers target application resources. Device 1598 implementations MUST report one of the following logical Android framework 1599 densities through the <code>android.util.DisplayMetrics</code> APIs, and MUST 1600 execute applications at this standard density. 1601 <ul> 1602 <li>120 dpi, known as 'ldpi'</li> 1603 <li>160 dpi, known as 'mdpi'</li> 1604 <li>213 dpi, known as 'tvdpi'</li> 1605 <li>240 dpi, known as 'hdpi'</li> 1606 <li>320 dpi, known as 'xhdpi'</li> 1607 <li>480 dpi, known as 'xxhdpi'</li> 1608 </ul> 1609 Device implementations SHOULD define the standard Android framework density 1610 that is numerically closest to the physical density of the screen, unless that 1611 logical density pushes the reported screen size below the minimum supported. 1612 If the standard Android framework density that is numerically closest to the 1613 physical density results in a screen size that is smaller than the smallest 1614 supported compatible screen size (320 dp width), device implementations SHOULD 1615 report the next lowest standard Android framework density.</p> 1616 1617 <a name="section-7.1.2"></a><h4>7.1.2. Display Metrics</h4> 1618 <p>Device implementations MUST report correct values for all display metrics 1619 defined in <code>android.util.DisplayMetrics</code> [<a 1620 href="#resources39">Resources, 39</a>].</p> 1621 1622 <a name="section-7.1.3"></a><h4>7.1.3. Screen Orientation</h4> 1623 <p>Devices MUST support dynamic orientation by applications to 1624 either portrait or landscape screen orientation. That is, the device must 1625 respect the application's request for a specific screen orientation. Device 1626 implementations MAY select either portrait or landscape orientation as the 1627 default.</p> 1628 <p>Devices MUST report the correct value for the device's current orientation, 1629 whenever queried via the android.content.res.Configuration.orientation, 1630 android.view.Display.getOrientation(), or other APIs.</p> 1631 <p>Devices MUST NOT change the reported screen size or density when changing 1632 orientation.</p> 1633 <p>Devices MUST report which screen orientations they support ( 1634 <code>android.hardware.screen.portrait</code> and/or 1635 <code>android.hardware.screen.landscape</code>) and MUST report at least one 1636 supported orientation. For example, a device with a fixed-orientation 1637 landscape screen, such as a television or laptop, MUST only report 1638 <code>android.hardware.screen.landscape</code>.</p> 1639 1640 <a name="section-7.1.4"></a><h4>7.1.4. 2D and 3D Graphics Acceleration</h4> 1641 <p>Device implementations MUST support both OpenGL ES 1.0 and 2.0, as embodied 1642 and detailed in the Android SDK documentations. Device implementations MUST 1643 also support Android Renderscript, as detailed in the Android SDK 1644 documentation [<a href="#resources08">Resources, 8</a>].</p> 1645 <p>Device implementations MUST also correctly identify themselves as 1646 supporting OpenGL ES 1.0 and 2.0. That is:</p> 1647 <ul> 1648 <li>The managed APIs (such as via the <code>GLES10.getString()</code> method) 1649 MUST report support for OpenGL ES 1.0 and 2.0</li> 1650 <li>The native C/C++ OpenGL APIs (that is, those available to apps via 1651 libGLES_v1CM.so, libGLES_v2.so, or libEGL.so) MUST report support for 1652 OpenGL ES 1.0 and 2.0.</li> 1653 </ul> 1654 <p>Device implementations MAY implement any desired OpenGL ES extensions. 1655 However, device implementations MUST report via the OpenGL ES managed and 1656 native APIs all extension strings that they do support, and conversely MUST 1657 NOT report extension strings that they do not support.</p> 1658 <p>Note that Android 4.2 includes support for applications to optionally 1659 specify that they require specific OpenGL texture compression formats. These 1660 formats are typically vendor-specific. Device implementations are not required 1661 by Android 4.2 to implement any specific texture compression format. However, 1662 they SHOULD accurately report any texture compression formats that they do 1663 support, via the <code>getString()</code> method in the OpenGL API.</p> 1664 1665 <p>Android 4.2 includes a mechanism for applications to declare that they 1666 wanted to enable hardware acceleration for 2D graphics at the Application, 1667 Activity, Window or View level through the use of a manifest tag 1668 <code>android:hardwareAccelerated</code> or direct API calls 1669 [<a href="#resources09">Resources, 9</a>].</p> 1670 <p>In Android 4.2, device implementations MUST enable hardware acceleration by 1671 default, and MUST disable hardware acceleration if the developer so requests 1672 by setting <code>android:hardwareAccelerated="false"</code> or disabling 1673 hardware acceleration directly through the Android View APIs.</p> 1674 <p>In addition, device implementations MUST exhibit behavior consistent with the 1675 Android SDK documentation on hardware acceleration 1676 [<a href="#resources09">Resources, 9</a>].</p> 1677 <p>Android 4.2 includes a <code>TextureView</code> object that lets developers 1678 directly integrate hardware-accelerated OpenGL ES textures as rendering targets 1679 in a UI hierarchy. Device implementations MUST support the <code>TextureView 1680 </code> API, and MUST exhibit consistent behavior with the upstream Android 1681 implementation.</p> 1682 1683 <a name="section-7.1.5"></a><h4>7.1.5. Legacy Application Compatibility Mode</h4> 1684 <p>Android 4.2 specifies a "compatibility mode" in which the framework 1685 operates in an 'normal' screen size equivalent (320dp width) mode for the benefit 1686 of legacy applications not developed for old versions of Android that pre-date 1687 screen-size independence. Device implementations MUST include support for legacy 1688 application compatibility mode as implemented by the upstream Android open source 1689 code. That is, device implementations MUST NOT alter the triggers or thresholds at 1690 which compatibility mode is activated, and MUST NOT alter the behavior of the 1691 compatibility mode itself.</p> 1692 1693 <a name="section-7.1.6"></a><h4>7.1.6. Screen Types</h4> 1694 <p>Device implementation screens are classified as one of two types:</p> 1695 <ul> 1696 <li>Fixed-pixel display implementations: the screen is a single panel that supports only a 1697 single pixel width and height. Typically the screen is physically integrated with 1698 the device. Examples include mobile phones, tablets, and so on.</li> 1699 <li>Variable-pixel display implementations: the device implementation either has no 1700 embedded screen and includes a video output port such as VGA, HDMI or a wireless port 1701 for display, or has an embedded screen that can change pixel dimensions. Examples 1702 include televisions, set-top boxes, and so on.</li> 1703 </ul> 1704 <p style="font-weight: bold;">Fixed-Pixel Device Implementations</p> 1705 <p>Fixed-pixel device implementations MAY use screens of any pixel dimensions, provided 1706 that they meet the requirements defined this Compatibility Definition.</p> 1707 <p>Fixed-pixel implementations MAY include a video output port for use with an 1708 external display. However, if that display is ever used for running apps, the 1709 device MUST meet the following requirements:</p> 1710 <ul> 1711 <li>The device MUST report the same screen configuration and display metrics, as detailed 1712 in Sections 7.1.1 and 7.1.2, as the fixed-pixel display.</li> 1713 <li>The device MUST report the same logical density as the fixed-pixel display.</li> 1714 <li>The device MUST report screen dimensions that are the same as, or very close to, 1715 the fixed-pixel display.</li> 1716 </ul> 1717 <p>For example, a tablet that is 7" diagonal size with a 1024x600 pixel resolution is 1718 considered a fixed-pixel large mdpi display implementation. If it contains a video 1719 output port that displays at 720p or 1080p, the device implementation MUST scale the output so that 1720 applications are only executed in a large mdpi window, regardless of whether the fixed-pixel display 1721 or video output port is in use.</p> 1722 1723 <p style="font-weight: bold;">Variable-Pixel Device Implementations</p> 1724 <p>Variable-pixel device implementations MUST support one or both of 1280x720, 1725 or 1920x1080 (that is, 720p or 1080p). Device implementations with 1726 variable-pixel displays MUST NOT support any other screen configuration or 1727 mode. Device implementations with variable-pixel screens MAY change screen 1728 configuration or mode at runtime or boot-time. For example, a user of a 1729 set-top box may replace a 720p display with a 1080p display, and the device 1730 implementation may adjust accordingly.</p> 1731 1732 <p>Additionally, variable-pixel device implementations MUST report the following 1733 configuration buckets for these pixel dimensions:</p> 1734 <ul> 1735 <li>1280x720 (also known as 720p): 'large' screen size, 'tvdpi' (213 dpi) 1736 density</li> 1737 <li>1920x1080 (also known as 1080p): 'large' screen size, 'xhdpi' (320 dpi) 1738 density</li> 1739 </ul> 1740 <p>For clarity, device implementations with variable pixel dimensions are 1741 restricted to 720p or 1080p in Android 4.2, and MUST be configured to report 1742 screen size and density buckets as noted above.</p> 1743 1744 <a name="section-7.1.7"></a><h4>7.1.7. Screen Technology</h4> 1745 <p>The Android platform includes APIs that allow applications to render rich 1746 graphics to the display. Devices MUST support all of these APIs as defined by 1747 the Android SDK unless specifically allowed in this document. Specifically:</p> 1748 <ul> 1749 <li>Devices MUST support displays capable of rendering 16-bit color graphics and 1750 SHOULD support displays capable of 24-bit color graphics.</li> 1751 <li>Devices MUST support displays capable of rendering animations.</li> 1752 <li>The display technology used MUST have a pixel aspect ratio (PAR) between 1753 0.9 and 1.1. That is, the pixel aspect ratio MUST be near square (1.0) with 1754 a 10% tolerance.</li> 1755 </ul> 1756 <a name="section-7.1.8"></a><h4>7.1.8. External Displays</h4> 1757 <p>Android 4.2 includes support for secondary display to enable media sharing capabilities and 1758 developer APIs for accessing external displays. If a device supports an external display either via 1759 a wired, wireless or an embedded additional display connection then the device implementation MUST 1760 implement the display manager API as described in the Android SDK documentation [<a href="#resources75">Resources, 75</a>]. 1761 Device implementations that support secure video output and are capable of supporting secure surfaces MUST declare support 1762 for <code>Display.SECURE_FLAG</code>. Specifically, device implementations that declare support for <code>Display.SECURE_FLAG</code>, 1763 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 1764 Android open source implementation includes support for wireless (Miracast) and wired (HDMI) displays that satisfies this requirement.</p> 1765 1766 <a name="section-7.2"></a><h3>7.2. Input Devices</h3> 1767 <a name="section-7.2.1"></a><h4>7.2.1. Keyboard</h4> 1768 <p>Device implementations:</p> 1769 <ul> 1770 <li>MUST include support for the Input Management Framework (which allows third 1771 party developers to create Input Management Engines - i.e. soft keyboard) as 1772 detailed at <a href="http://developer.android.com">http://developer.android.com</a> 1773 </li> 1774 <li>MUST provide at least one soft keyboard implementation (regardless of whether 1775 a hard keyboard is present)</li> 1776 <li>MAY include additional soft keyboard implementations</li> 1777 <li>MAY include a hardware keyboard</li> 1778 <li>MUST NOT include a hardware keyboard that does not match one of the 1779 formats specified in <code>android.content.res.Configuration.keyboard</code> 1780 [<a href="#resources40">Resources, 40</a>] (that is, QWERTY, or 12-key)</li> 1781 </ul> 1782 <a name="section-7.2.2"></a><h4>7.2.2. Non-touch Navigation</h4> 1783 <p>Device implementations:</p> 1784 <ul> 1785 <li>MAY omit a non-touch navigation option (that is, may omit a trackball, d-pad, 1786 or wheel)</li> 1787 <li>MUST report the correct value for 1788 <code>android.content.res.Configuration.navigation</code> 1789 [<a href="#resources40">Resources, 40</a>]</li> 1790 <li>MUST provide a reasonable alternative user interface mechanism for the 1791 selection and editing of text, compatible with Input Management Engines. The 1792 upstream Android open source implementation includes a selection mechanism suitable 1793 for use with devices that lack non-touch navigation inputs.</li> 1794 </ul> 1795 <a name="section-7.2.3"></a><h4>7.2.3. Navigation keys</h4> 1796 <p>The Home, Menu and Back functions are essential to the Android navigation 1797 paradigm. Device implementations MUST make these functions available to the 1798 user at all times when running applications. These functions MAY be implemented 1799 via dedicated physical buttons (such as mechanical or capacitive touch buttons), 1800 or MAY be implemented using dedicated software keys, gestures, touch panel, etc. 1801 Android 4.2 supports both implementations.</p> 1802 1803 <p>Android 4.2 includes support for assist action [<a href="#resources63">Resources, 63</a>]. 1804 Device implementations MUST make the assist action available to the user at all times when running applications. 1805 This function MAY be implemented via hardware or software keys.</p> 1806 1807 <p>Device implementations MAY use a distinct portion of the screen to display 1808 the navigation keys, but if so, MUST meet these requirements:</p> 1809 1810 <ul> 1811 <li>Device implementation navigation keys MUST use a distinct portion of the 1812 screen, not available to applications, and MUST NOT obscure or otherwise 1813 interfere with the portion of the screen available to applications.</li> 1814 <li>Device implementations MUST make available a portion of the display to 1815 applications that meets the requirements defined in 1816 <a href="section-7.1.1">Section 7.1.1</a>.</li> 1817 <li>Device implementations MUST display the navigation keys when applications 1818 do not specify a system UI mode, or specify 1819 <code>SYSTEM_UI_FLAG_VISIBLE</code>.</li> 1820 <li>Device implementations MUST present the navigation keys in an unobtrusive 1821 "low profile" (eg. dimmed) mode when applications specify 1822 <code>SYSTEM_UI_FLAG_LOW_PROFILE</code>.</li> 1823 <li>Device implementations MUST hide the navigation keys when applications 1824 specify <code>SYSTEM_UI_FLAG_HIDE_NAVIGATION</code>.</li> 1825 <li>Device implementation MUST present a Menu key to applications when 1826 targetSdkVersion <= 10 and SHOULD NOT present a Menu key when the 1827 targetSdkVersion > 10.</li> 1828 </ul> 1829 1830 <a name="section-7.2.4"></a><h4>7.2.4. Touchscreen input</h4> 1831 <p>Device implementations:</p> 1832 <ul> 1833 <li>MUST have a pointer input system of some kind (either mouse-like, or 1834 touch)</li> 1835 <li>MAY have a touchscreen of any modality (such as capacitive or resistive)</li> 1836 <li>SHOULD support fully independently tracked pointers, if a touchscreen 1837 supports multiple pointers</li> 1838 <li>MUST report the value of <code>android.content.res.Configuration</code> 1839 [<a href="#resources40">Resources, 39</a>] 1840 reflecting corresponding to the type of the specific touchscreen on the 1841 device</li> 1842 </ul> 1843 <p>Device implementations MUST report the correct feature corresponding to the 1844 type of input used. Note that Android 4.2 includes the feature 1845 <code>android.hardware.faketouch</code>, which corresponds to a high-fidelity 1846 non-touch (that is, pointer-based) input device such as a mouse or trackpad that 1847 can adequately emulate touch-based input (including basic gesture support), 1848 and indicates that the device supports an emulated subset of touchscreen 1849 functionality. 1850 Device implementations that include a touchscreen (single-touch or better) 1851 MUST also report android.hardware.faketouch. Device implementations that do 1852 not include a touchscreen (and rely on a pointer device only) MUST NOT report 1853 any touchscreen feature, and MUST report only 1854 <code>android.hardware.faketouch</code>.</p> 1855 <a name="section-7.2.5"></a><h4>7.2.5. Microphone</h4> 1856 <p>Device implementations MAY omit a microphone. However, if a device 1857 implementation omits a microphone, it MUST NOT report the 1858 <code>android.hardware.microphone</code> feature constant, and must implement 1859 the audio recording API as no-ops, per <a href="section-7">Section 7</a>. 1860 Conversely, device implementations that do possess a microphone:</p> 1861 <ul> 1862 <li>MUST report the <code>android.hardware.microphone</code> feature constant</li> 1863 <li>SHOULD meet the audio quality requirements in <a href="section-5.4">Section 5.4</a></li> 1864 <li>SHOULD meet the audio latency requirements in <a href="section-5.5">Section 5.5</a></li> 1865 </ul> 1866 1867 <a name="section-7.3"></a><h3>7.3. Sensors</h3> 1868 <p>Android 4.2 includes APIs for accessing a variety of sensor types. Devices 1869 implementations generally MAY omit these sensors, as provided for in the 1870 following subsections. If a device includes a particular sensor type that has a 1871 corresponding API for third-party developers, the device implementation MUST 1872 implement that API as described in the Android SDK documentation. For example, 1873 device implementations:</p> 1874 <ul> 1875 <li>MUST accurately report the presence or absence of sensors per the 1876 <code>android.content.pm.PackageManager</code> class. [<a 1877 href="#resources37">Resources, 37</a>]</li> 1878 <li>MUST return an accurate list of supported sensors via the 1879 <code>SensorManager.getSensorList()</code> and similar methods</li> 1880 <li>MUST behave reasonably for all other sensor APIs (for example, by 1881 returning true or false as appropriate when applications attempt to register 1882 listeners, not calling sensor listeners when the corresponding sensors are not 1883 present; etc.)</li> 1884 <li>MUST report all sensor measurements using the relevant International System 1885 of Units (i.e. metric) values for each sensor type as defined in the Android SDK 1886 documentation [<a href="#resources41">Resources, 41</a>]</li> 1887 </ul> 1888 <p>The list above is not comprehensive; the documented behavior of the Android 1889 SDK is to be considered authoritative.</p> 1890 <p>Some sensor types are synthetic, meaning they can be derived from data 1891 provided by one or more other sensors. (Examples include the orientation 1892 sensor, and the linear acceleration sensor.) Device implementations SHOULD 1893 implement these sensor types, when they include the prerequisite physical 1894 sensors.</p> 1895 <p>The Android 4.2 includes a notion of a "streaming" sensor, which is 1896 one that returns data continuously, rather than only when the data changes. 1897 Device implementations MUST continuously provide periodic data samples for any 1898 API indicated by the Android 4.2 SDK documentation to be a streaming 1899 sensor. Note that the device implementations MUST ensure that the sensor stream must not 1900 prevent the device CPU from entering a suspend state or waking up from a suspend state.</p> 1901 1902 <a name="section-7.3.1"></a><h4>7.3.1. Accelerometer</h4> 1903 <p>Device implementations SHOULD include a 3-axis accelerometer. If a device 1904 implementation does include a 3-axis accelerometer, it:</p> 1905 <ul> 1906 <li>SHOULD be able to deliver events at 120 Hz or greater. Note that while the 1907 accelerometer frequency above is stated as "SHOULD" for Android 4.2, the Compatibility Definition 1908 for a future version is planned to change these to "MUST". That is, these standards are 1909 optional in Android 4.2 but <b>will be required</b> in future versions. Existing and 1910 new devices that run Android 4.2 are <b>very strongly encouraged to meet these requirements 1911 in Android 4.2</b> so they will be able to upgrade to the future platform releases 1912 </li> 1913 <li>MUST comply with the Android sensor coordinate system as detailed 1914 in the Android APIs (see [<a href="#resources41">Resources, 41</a>])</li> 1915 <li>MUST be capable of measuring from freefall up to twice gravity (2g) or 1916 more on any three-dimensional vector</li> 1917 <li>MUST have 8-bits of accuracy or more</li> 1918 <li>MUST have a standard deviation no greater than 0.05 m/s^2</li> 1919 </ul> 1920 <a name="section-7.3.2"></a><h4>7.3.2. Magnetometer</h4> 1921 <p>Device implementations SHOULD include a 3-axis magnetometer (i.e. compass.) 1922 If a device does include a 3-axis magnetometer, it:</p> 1923 <ul> 1924 <li>MUST be able to deliver events at 10 Hz or greater</li> 1925 <li>MUST comply with the Android sensor coordinate system as detailed 1926 in the Android APIs (see [<a href="#resources41">Resources, 41</a>]).</li> 1927 <li>MUST be capable of sampling a range of field strengths adequate to cover the 1928 geomagnetic field</li> 1929 <li>MUST have 8-bits of accuracy or more</li> 1930 <li>MUST have a standard deviation no greater than 0.5 µT</li> 1931 </ul> 1932 <a name="section-7.3.3"></a><h4>7.3.3. GPS</h4> 1933 <p>Device implementations SHOULD include a GPS receiver. If a device 1934 implementation does include a GPS receiver, it SHOULD include 1935 some form of "assisted GPS" technique to minimize GPS lock-on time.</p> 1936 <a name="section-7.3.4"></a><h4>7.3.4. Gyroscope</h4> 1937 <p>Device implementations SHOULD include a gyroscope (i.e. angular change 1938 sensor.) Devices SHOULD NOT include a gyroscope sensor unless a 3-axis 1939 accelerometer is also included. If a device implementation includes a 1940 gyroscope, it:</p> 1941 <ul> 1942 <li>MUST be temperature compensated</li> 1943 <li>MUST be capable of measuring orientation changes up to 5.5*Pi 1944 radians/second (that is, approximately 1,000 degrees per second)</li> 1945 <li>SHOULD be able to deliver events at 200 Hz or greater. Note that while the 1946 gyroscope frequency above is stated as "SHOULD" for Android 4.2, the Compatibility Definition 1947 for a future version is planned to change these to "MUST". That is, these standards are 1948 optional in Android 4.2 but <b>will be required</b> in future versions. Existing and 1949 new devices that run Android 4.2 are <b>very strongly encouraged to meet these requirements 1950 in Android 4.2</b> so they will be able to upgrade to the future platform releases 1951 </li> 1952 <li>MUST have 12-bits of accuracy or more</li> 1953 <li>MUST have a variance no greater than 1e-7 rad^2 / s^2 per Hz (variance per Hz, or rad^2 / s). 1954 The variance is allowed to vary with the sampling rate, but must be constrained by this value. 1955 In other words, if you measure the variance of the gyro at 1 Hz sampling rate it should be no 1956 greater than 1e-7 rad^2/s^2. </li> 1957 <li>MUST have timestamps as close to when the hardware event happened as possible. The constant latency must be removed.</li> 1958 </ul> 1959 <a name="section-7.3.5"></a><h4>7.3.5. Barometer</h4> 1960 <p>Device implementations MAY include a barometer (i.e. ambient air pressure 1961 sensor.) If a device implementation includes a barometer, it:</p> 1962 <ul> 1963 <li>MUST be able to deliver events at 5 Hz or greater</li> 1964 <li>MUST have adequate precision to enable estimating altitude</li> 1965 <li>MUST be temperature compensated</li> 1966 </ul> 1967 <a name="section-7.3.6"></a><h4>7.3.7. Thermometer</h4> 1968 <p>Device implementations MAY but SHOULD NOT include a thermometer (i.e. 1969 temperature sensor.) If a device implementation does include a thermometer, it 1970 MUST measure the temperature of the device CPU. It MUST NOT measure any other 1971 temperature. (Note that this sensor type is deprecated in the Android 4.2 1972 APIs.)</p> 1973 <a name="section-7.3.7"></a><h4>7.3.7. Photometer</h4> 1974 <p>Device implementations MAY include a photometer (i.e. ambient light 1975 sensor.)</p> 1976 <a name="section-7.3.8"></a><h4>7.3.8. Proximity Sensor</h4> 1977 <p>Device implementations MAY include a proximity sensor. If a device 1978 implementation does include a proximity sensor, it MUST measure the proximity 1979 of an object in the same direction as the screen. That is, the proximity 1980 sensor MUST be oriented to detect objects close to the screen, as the 1981 primary intent of this sensor type is to detect a phone in use by the 1982 user. If a device implementation includes a proximity sensor with any other 1983 orientation, it MUST NOT be accessible through this API. If a device 1984 implementation has a proximity sensor, it MUST be have 1-bit of accuracy or 1985 more.</p> 1986 1987 <a name="section-7.4"></a><h3>7.4. Data Connectivity</h3> 1988 <a name="section-7.4.1"></a><h4>7.4.1. Telephony</h4> 1989 <p>"Telephony" as used by the Android 4.2 APIs and this document refers 1990 specifically to hardware related to placing voice calls and sending SMS 1991 messages via a GSM or CDMA network. While these voice calls may or may not be 1992 packet-switched, they are for the purposes of Android 4.2 considered 1993 independent of any data connectivity that may be implemented using the same 1994 network. In other words, the Android "telephony" functionality and APIs refer 1995 specifically to voice calls and SMS; for instance, device implementations that 1996 cannot place calls or send/receive SMS messages MUST NOT report the 1997 "android.hardware.telephony" feature or any sub-features, regardless of 1998 whether they use a cellular network for data connectivity.</p> 1999 <p>Android 4.2 MAY be used on devices that do not include telephony hardware. 2000 That is, Android 4.2 is compatible with devices that are not phones. 2001 However, if a device implementation does include GSM or CDMA telephony, it 2002 MUST implement full support for the API for that technology. Device 2003 implementations that do not include telephony hardware MUST implement the full 2004 APIs as no-ops.</p> 2005 <a name="section-7.4.2"></a><h4>7.4.2. IEEE 802.11 (WiFi)</h4> 2006 <p>Android 4.2 device implementations SHOULD include support for one or more 2007 forms of 802.11 (b/g/a/n, etc.) If a device implementation does include 2008 support for 802.11, it MUST implement the corresponding Android API.</p> 2009 <p>Device implementations MUST implement the multicast API as described in 2010 the SDK documentation [<a href="#resources62">Resources, 62</a>]. Device 2011 implementations that do include Wifi support MUST support multicast DNS (mDNS). 2012 Device implementations MUST not filter mDNS packets (224.0.0.251) at any time 2013 of operation including when the screen is not in an active state.</p> 2014 2015 <a name="section-7.4.2.1"></a><h4>7.4.2.1. WiFi Direct</h4> 2016 <p>Device implementations SHOULD include support for Wifi direct (Wifi peer-to-peer). 2017 If a device implementation does include support for Wifi direct, it MUST implement the corresponding 2018 Android API as described in the SDK documentation [<a href="#resources68">Resources, 68</a>]. 2019 If a device implementation includes support for Wifi direct, then it:</p> 2020 <ul> 2021 <li>MUST support regular Wifi operation</li> 2022 <li>SHOULD support concurrent wifi and wifi Direct operation</li> 2023 </ul> 2024 2025 <a name="section-7.4.3"></a><h4>7.4.3. Bluetooth</h4> 2026 <p>Device implementations SHOULD include a Bluetooth transceiver. Device 2027 implementations that do include a Bluetooth transceiver MUST enable the 2028 RFCOMM-based Bluetooth API as described in the SDK documentation [<a 2029 href="#resources42">Resources, 42</a>]. Device implementations SHOULD 2030 implement relevant Bluetooth profiles, such as A2DP, AVRCP, OBEX, etc. as 2031 appropriate for the device.</p> 2032 <p>The Compatibility Test Suite includes cases that cover basic operation of 2033 the Android RFCOMM Bluetooth API. However, since Bluetooth is a communications 2034 protocol between devices, it cannot be fully tested by unit tests running on a 2035 single device. Consequently, device implementations MUST also pass the 2036 human-driven Bluetooth test procedure described in Appendix A.</p> 2037 2038 <a name="section-7.4.4"></a><h4>7.4.4. Near-Field Communications</h4> 2039 <p>Device implementations SHOULD include a transceiver and related hardware 2040 for Near-Field Communications (NFC). If a device implementation does include 2041 NFC hardware, then it:</p> 2042 <ul> 2043 <li>MUST report the android.hardware.nfc feature from the 2044 <code>android.content.pm.PackageManager.hasSystemFeature()</code> method. 2045 [<a href="#resources37">Resources, 37</a>]</li> 2046 <li>MUST be capable of reading and writing NDEF messages via the following NFC 2047 standards: 2048 <ul> 2049 <li>MUST be capable of acting as an NFC Forum reader/writer 2050 (as defined by the NFC Forum technical specification 2051 NFCForum-TS-DigitalProtocol-1.0) via the following NFC standards: 2052 <ul> 2053 <li>NfcA (ISO14443-3A)</li> 2054 <li>NfcB (ISO14443-3B) </li> 2055 <li>NfcF (JIS 6319-4)</li> 2056 <li>IsoDep (ISO 14443-4)</li> 2057 <li>NFC Forum Tag Types 1, 2, 3, 4 (defined by the NFC Forum)</li> 2058 </ul> 2059 </li> 2060 </ul> 2061 </li> 2062 <li>SHOULD be capable of reading and writing NDEF messages via the following 2063 NFC standards. Note that while the NFC standards below are stated as 2064 "SHOULD" for Android 4.2, the Compatibility Definition for a future 2065 version is planned to change these to "MUST". That is, these standards are 2066 optional in Android 4.2 but <b>will be required</b> in future versions. 2067 Existing and new devices that run Android 4.2 are <b>very strongly 2068 encouraged to meet these requirements in Android 4.2</b> so they will be 2069 able to upgrade to the future platform releases. 2070 <ul> 2071 <li>NfcV (ISO 15693)</li> 2072 </ul> 2073 </li> 2074 <li>MUST be capable of transmitting and receiving data via the following 2075 peer-to-peer standards and protocols: 2076 <ul> 2077 <li>ISO 18092</li> 2078 <li>LLCP 1.0 (defined by the NFC Forum)</li> 2079 <li>SDP 1.0 (defined by the NFC Forum)</li> 2080 <li>NDEF Push Protocol [<a href="#resources43">Resources, 43</a>]</li> 2081 <li>SNEP 1.0 (defined by the NFC Forum)</li> 2082 </ul> 2083 </li> 2084 <li>MUST include support for Android Beam [<a href="#resources65">Resources, 65</a>]: 2085 <ul> 2086 <li>MUST implement the SNEP default server. Valid NDEF messages received 2087 by the default SNEP server MUST be dispatched to applications using 2088 the android.nfc.ACTION_NDEF_DISCOVERED intent. Disabling Android Beam 2089 in settings MUST NOT disable dispatch of incoming NDEF message.</li> 2090 <li>Device implementations MUST honor the android.settings.NFCSHARING_SETTINGS intent 2091 to show NFC sharing settings [<a href="#resources67">Resources, 67</a>].</li> 2092 <li>MUST implement the NPP server. Messages received by the NPP server MUST 2093 be processed the same way as the SNEP default server.</li> 2094 <li>MUST implement a SNEP client and attempt to send outbound P2P NDEF to 2095 the default SNEP server when Android Beam is enabled. If no default 2096 SNEP server is found then the client MUST attempt to send to an NPP 2097 server.</li> 2098 <li>MUST allow foreground activities to set the outbound P2P NDEF message 2099 using android.nfc.NfcAdapter.setNdefPushMessage, and 2100 android.nfc.NfcAdapter.setNdefPushMessageCallback, and 2101 android.nfc.NfcAdapter.enableForegroundNdefPush.</li> 2102 <li>SHOULD use a gesture or on-screen confirmation, such as 'Touch to Beam', 2103 before sending outbound P2P NDEF messages.</li> 2104 <li>SHOULD enable Android Beam by default</li> 2105 <li>MUST support NFC Connection handover to Bluetooth when the device supports Bluetooth Object Push Profile. 2106 Device implementations must support connection handover to Bluetooth when using android.nfc.NfcAdapter.setBeamPushUris, 2107 by implementing the "Connection Handover version 1.2" [<a href="#resources60">Resources, 60</a>] 2108 and "Bluetooth Secure Simple Pairing Using NFC version 1.0" [<a href="#resources61">Resources, 61</a>] 2109 specs from the NFC Forum. Such an implementation SHOULD use SNEP GET 2110 requests for exchanging the handover request / select records over NFC, and it MUST 2111 use the Bluetooth Object Push Profile for the actual Bluetooth data transfer.</li> 2112 </ul> 2113 </li> 2114 <li>MUST poll for all supported technologies while in NFC discovery mode.</li> 2115 <li>SHOULD be in NFC discovery mode while the device is awake with the screen active 2116 and the lock-screen unlocked.</li> 2117 </ul> 2118 2119 <p>(Note that publicly available links are not available for the JIS, ISO, and 2120 NFC Forum specifications cited above.)</p> 2121 <p>Additionally, device implementations MAY include reader/writer support for 2122 the following MIFARE technologies.</p> 2123 <ul> 2124 <li>MIFARE Classic (NXP MF1S503x [<a href="#resources44">Resources, 44</a>], 2125 MF1S703x [<a href="#resources44">Resources, 44</a>])</li> 2126 <li>MIFARE Ultralight (NXP MF0ICU1 [<a href="#resources46">Resources, 46</a>], 2127 MF0ICU2 [<a href="#resources46">Resources, 46</a>])</li> 2128 <li>NDEF on MIFARE Classic (NXP AN130511 [<a href="#resources48">Resources, 48</a>], 2129 AN130411 [<a href="#resources49">Resources, 49</a>])</li> 2130 </ul> 2131 <p>Note that Android 4.2 includes APIs for these MIFARE types. If a 2132 device implementation supports MIFARE in the reader/writer role, it:</p> 2133 <ul> 2134 <li>MUST implement the corresponding Android APIs as documented by the 2135 Android SDK</li> 2136 <li>MUST report the feature com.nxp.mifare from the 2137 <code>android.content.pm.PackageManager.hasSystemFeature()</code> method. 2138 [<a href="#resources37">Resources, 37</a>] Note that this is not a standard 2139 Android feature, and as such does not appear as a constant on the 2140 <code>PackageManager</code> class.</li> 2141 <li>MUST NOT implement the corresponding Android APIs nor report the 2142 com.nxp.mifare feature unless it also implements general NFC support as 2143 described in this section</li> 2144 </ul> 2145 <p>If a device implementation does not include NFC hardware, it MUST NOT 2146 declare the android.hardware.nfc feature from the 2147 <code>android.content.pm.PackageManager.hasSystemFeature()</code> method [<a 2148 href="#resources37">Resources, 37</a>], and MUST implement the Android 4.2 NFC 2149 API as a no-op.</p> 2150 <p>As the classes <code>android.nfc.NdefMessage</code> and 2151 <code>android.nfc.NdefRecord</code> represent a protocol-independent data 2152 representation format, device implementations MUST implement these APIs even 2153 if they do not include support for NFC or declare the android.hardware.nfc 2154 feature.</p> 2155 <a name="section-7.4.5"></a><h4>7.4.5. Minimum Network Capability</h4> 2156 <p>Device implementations MUST include support for one or more forms of data 2157 networking. Specifically, device implementations MUST include support for at 2158 least one data standard capable of 200Kbit/sec or greater. Examples of 2159 technologies that satisfy this requirement include EDGE, HSPA, EV-DO, 802.11g, 2160 Ethernet, etc.</p> 2161 <p>Device implementations where a physical networking standard (such as 2162 Ethernet) is the primary data connection SHOULD also include support for at 2163 least one common wireless data standard, such as 802.11 (WiFi).</p> 2164 <p>Devices MAY implement more than one form of data connectivity.</p> 2165 2166 2167 <a name="section-7.5"></a><h3>7.5. Cameras</h3> 2168 <p>Device implementations SHOULD include a rear-facing camera, and MAY include 2169 a front-facing camera. A rear-facing camera is a camera located on the side of 2170 the device opposite the display; that is, it images scenes on the far side of 2171 the device, like a traditional camera. A front-facing camera is a camera 2172 located on the same side of the device as the display; that is, a camera 2173 typically used to image the user, such as for video conferencing and similar 2174 applications.</p> 2175 <a name="section-7.5.1"></a><h4>7.5.1. Rear-Facing Camera</h4> 2176 <p>Device implementations SHOULD include a rear-facing camera. If a device 2177 implementation includes a rear-facing camera, it:</p> 2178 <ul> 2179 <li>MUST have a resolution of at least 2 megapixels</li> 2180 <li>SHOULD have either hardware auto-focus, or software auto-focus implemented 2181 in the camera driver (transparent to application software)</li> 2182 <li>MAY have fixed-focus or EDOF (extended depth of field) hardware</li> 2183 <li>MAY include a flash. If the Camera includes a flash, the flash lamp MUST 2184 NOT be lit while an android.hardware.Camera.PreviewCallback instance has been 2185 registered on a Camera preview surface, unless the application has explicitly 2186 enabled the flash by enabling the <code>FLASH_MODE_AUTO</code> or 2187 <code>FLASH_MODE_ON</code> attributes of a <code>Camera.Parameters</code> 2188 object. Note that this constraint does not apply to the device's built-in 2189 system camera application, but only to third-party applications using 2190 <code>Camera.PreviewCallback</code>.</li> 2191 </ul> 2192 <a name="section-7.5.2"></a><h4>7.5.2. Front-Facing Camera</h4> 2193 <p>Device implementations MAY include a front-facing camera. If a device 2194 implementation includes a front-facing camera, it:</p> 2195 <ul> 2196 <li>MUST have a resolution of at least VGA (that is, 640x480 pixels)</li> 2197 <li>MUST NOT use a front-facing camera as the default for the Camera API. 2198 That is, the camera API in Android 4.2 has specific support for front-facing 2199 cameras, and device implementations MUST NOT configure the API to to treat a 2200 front-facing camera as the default rear-facing camera, even if it is the only 2201 camera on the device.</li> 2202 <li>MAY include features (such as auto-focus, flash, etc.) 2203 available to rear-facing cameras as described in Section 7.5.1.</li> 2204 <li>MUST horizontally reflect (i.e. mirror) the stream displayed by an app in a 2205 CameraPreview, as follows:</li> 2206 <ul> 2207 <li>If the device implementation is capable of being rotated by user (such as 2208 automatically via an accelerometer or manually via user input), the camera 2209 preview MUST be mirrored horizontally relative to the device's current 2210 orientation.</li> 2211 <li>If the current application has explicitly requested that the Camera 2212 display be rotated via a call to the 2213 <code>android.hardware.Camera.setDisplayOrientation()</code> [<a 2214 href="#resources50">Resources, 50</a>] method, the camera preview MUST be 2215 mirrored horizontally relative to the orientation specified by the 2216 application.</li> 2217 <li>Otherwise, the preview MUST be mirrored along the device's default horizontal axis.</li> 2218 </ul> 2219 <li>MUST mirror the image displayed by the postview in the same manner as 2220 the camera preview image stream. (If the device implementation does not 2221 support postview, this requirement obviously does not apply.)</li> 2222 <li>MUST NOT mirror the final captured still image or video streams returned 2223 to application callbacks or committed to media storage</li> 2224 </ul> 2225 <a name="section-7.5.3"></a><h4>7.5.3. Camera API Behavior</h4> 2226 <p>Device implementations MUST implement the following behaviors for the 2227 camera-related APIs, for both front- and rear-facing cameras:</p> 2228 <ol> 2229 <li>If an application has never called 2230 <code>android.hardware.Camera.Parameters.setPreviewFormat(int)</code>, then the 2231 device MUST use <code>android.hardware.PixelFormat.YCbCr_420_SP</code> for 2232 preview data provided to application callbacks.</li> 2233 <li>If an application registers an <code>android.hardware.Camera.PreviewCallback 2234 </code> instance and the system calls the <code>onPreviewFrame()</code> method 2235 when the preview format is YCbCr_420_SP, the data in the <code>byte[]</code> 2236 passed into <code>onPreviewFrame()</code> must further be in the NV21 encoding 2237 format. That is, NV21 MUST be the default.</li> 2238 <li>Device implementations MUST support the YV12 format (as denoted by the 2239 <code>android.graphics.ImageFormat.YV12</code> constant) for camera previews 2240 for both front- and rear-facing cameras. (The hardware video encoder and camera 2241 may use any native pixel format, but the device implementation MUST support conversion 2242 to YV12.)</li> 2243 </ol> 2244 <p>Device implementations MUST implement the full Camera API included in the 2245 Android 4.2 SDK documentation [<a href="#resources51">Resources, 51</a>]), 2246 regardless of whether the device includes hardware autofocus or other 2247 capabilities. For instance, cameras that lack autofocus MUST still call any 2248 registered <code>android.hardware.Camera.AutoFocusCallback</code> instances (even though 2249 this has no relevance to a non-autofocus camera.) Note that this does apply 2250 to front-facing cameras; for instance, even though most front-facing cameras 2251 do not support autofocus, the API callbacks must still be "faked" as 2252 described.</p> 2253 <p>Device implementations MUST recognize and honor each parameter name defined 2254 as a constant on the <code>android.hardware.Camera.Parameters</code> class, if the 2255 underlying hardware supports the feature. If the device hardware does not 2256 support a feature, the API must behave as documented. Conversely, Device 2257 implementations MUST NOT honor or recognize string constants passed 2258 to the <code>android.hardware.Camera.setParameters()</code> method other than 2259 those documented as constants on the 2260 <code>android.hardware.Camera.Parameters</code>. That is, 2261 device implementations MUST support all standard Camera parameters if the 2262 hardware allows, and MUST NOT support custom Camera parameter types. 2263 For instance, device implementations that support image capture using high dynamic range (HDR) 2264 imaging techniques MUST support camera parameter <code>Camera.SCENE_MODE_HDR</code> 2265 [<a href="#resources78">Resources, 78</a>]).</p> 2266 <p>Device implementations MUST broadcast the <code>Camera.ACTION_NEW_PICTURE</code> 2267 intent whenever a new picture is taken by the camera and the entry of the picture 2268 has been added to the media store.</p> 2269 <p>Device implementations MUST broadcast the <code>Camera.ACTION_NEW_VIDEO</code> 2270 intent whenever a new video is recorded by the camera and the entry of the picture 2271 has been added to the media store.</p> 2272 <a name="section-7.5.4"></a><h4>7.5.4. Camera Orientation</h4> 2273 <p>Both front- and rear-facing cameras, if present, MUST be oriented so that 2274 the long dimension of the camera aligns with the screen's long dimention. That 2275 is, when the device is held in the landscape orientation, cameras MUST 2276 capture images in the landscape orientation. This applies regardless of the 2277 device's natural orientation; that is, it applies to landscape-primary devices 2278 as well as portrait-primary devices.</p> 2279 2280 <a name="section-7.6"></a><h3>7.6. Memory and Storage</h3> 2281 <a name="section-7.6.1"></a><h4>7.6.1. Minimum Memory and Storage</h4> 2282 <p>Device implementations MUST have at least 340MB of memory available to the 2283 kernel and userspace. The 340MB MUST be in addition to any memory dedicated to 2284 hardware components such as radio, video, and so on that is not under the 2285 kernel's control.</p> 2286 <p>Device implementations MUST have at least 350MB of non-volatile storage 2287 available for application private data. That is, the <code>/data</code> partition MUST be at 2288 least 350MB.</p> 2289 <p>The Android APIs include a Download Manager that applications may use to 2290 download data files [<a href="#resources56">Resources, 56</a>]. The device 2291 implementation of the Download Manager MUST be capable of downloading individual 2292 files of at least 100MB in size to the default "cache" location.</p> 2293 <a name="section-7.6.2"></a><h4>7.6.2. Application Shared Storage</h4> 2294 <p>Device implementations MUST offer shared storage for applications. The 2295 shared storage provided MUST be at least 1GB in size.</p> 2296 <p>Device implementations MUST be configured with shared storage mounted by 2297 default, "out of the box". If the shared storage is not mounted on the Linux 2298 path <code>/sdcard</code>, then the device MUST include a Linux symbolic link 2299 from <code>/sdcard</code> to the actual mount point.</p> 2300 <p>Device implementations MUST enforce as documented the 2301 <code>android.permission.WRITE_EXTERNAL_STORAGE</code> permission on this 2302 shared storage. Shared storage MUST otherwise be writable by any application 2303 that obtains that permission.</p> 2304 <p>Device implementations MAY have hardware for user-accessible removable 2305 storage, such as a Secure Digital card. Alternatively, device implementations 2306 MAY allocate internal (non-removable) storage as shared storage for apps.</p> 2307 <p>Regardless of the form of shared storage used, device implementations MUST 2308 provide some mechanism to access the contents of shared storage from a host 2309 computer, such as USB mass storage (UMS) or Media Transfer Protocol (MTP). Device 2310 implementations MAY use USB mass storage, but SHOULD use Media Transfer 2311 Protocol. If the device implementation supports Media Transfer Protocol:</p> 2312 <ul> 2313 <li>The device implementation SHOULD be compatible with the reference Android 2314 MTP host, Android File Transfer [<a href="#resources57">Resources, 57</a>].</li> 2315 <li>The device implementation SHOULD report a USB device class of <code>0x00</code>.</li> 2316 <li>The device implementation SHOULD report a USB interface name of 'MTP'.</li> 2317 </ul> 2318 <p>If the device implementation lacks USB ports, it MUST provide a host 2319 computer with access to the contents of shared storage by some other means, 2320 such as a network file system.</p> 2321 <p>It is illustrative to consider two common examples. If a device 2322 implementation includes an SD card slot to satisfy the shared storage 2323 requirement, a FAT-formatted SD card 1GB in size or larger MUST be included 2324 with the device as sold to users, and MUST be mounted by default. 2325 Alternatively, if a device implementation uses internal fixed storage to 2326 satisfy this requirement, that storage MUST be 1GB in size or larger 2327 and mounted on <code>/sdcard</code> (or <code>/sdcard</code> 2328 MUST be a symbolic link to the physical location if it is mounted elsewhere.)</p> 2329 <p>Device implementations that include multiple shared storage paths (such as 2330 both an SD card slot and shared internal storage) SHOULD modify the core 2331 applications such as the media scanner and ContentProvider to transparently 2332 support files placed in both locations.</p> 2333 2334 <a name="section-7.7"></a><h3>7.7. USB</h3> 2335 <p>Device implementations SHOULD include a USB client port, and SHOULD include 2336 a USB host port.</p> 2337 <p>If a device implementation includes a USB client port:</p> 2338 <ul> 2339 <li>the port MUST be connectable to a USB host with a standard USB-A port</li> 2340 <li>the port SHOULD use the micro USB form factor on the device side. Existing and 2341 new devices that run Android 4.2 are <b>very strongly encouraged to meet these requirements 2342 in Android 4.2</b> so they will be able to upgrade to the future platform releases</li> 2343 <li>the port SHOULD be centered in the middle of an edge. Device implementations SHOULD either 2344 locate the port on the bottom of the device (according to natural orientation) or enable software 2345 screen rotation for all apps (including home screen), so that the display draws correctly when the device 2346 is oriented with the port at bottom. Existing and new devices that run Android 4.2 are <b>very strongly 2347 encouraged to meet these requirements in Android 4.2</b> so they will be able to upgrade to future platform releases.</li> 2348 <li>if the device has other ports (such as a non-USB charging port) it SHOULD be on the same edge as the 2349 micro-USB port</li> 2350 <li>it MUST allow a host connected to the device to access the contents of the 2351 shared storage volume using either USB mass storage or Media Transfer 2352 Protocol</li> 2353 <li>it MUST implement the Android Open Accessory API and specification as documented 2354 in the Android SDK documentation, and MUST declare support for the hardware 2355 feature <code>android.hardware.usb.accessory</code> [<a href="#resources52">Resources, 2356 52</a>]</li> 2357 <li>it MUST implement the USB audio class as documented in the Android SDK documentation [<a href="#resources66">Resources, 66</a>]</li> 2358 <li>it SHOULD implement support for USB battery charging specification [<a href="#resources64">Resources, 64</a>] 2359 Existing and new devices that run Android 4.2 are <b>very strongly encouraged to meet these requirements in Android 4.2</b> 2360 so they will be able to upgrade to the future platform releases</li> 2361 2362 </ul> 2363 <p>If a device implementation includes a USB host port:</p> 2364 <ul> 2365 <li>it MAY use a non-standard port form factor, but if so MUST ship with a 2366 cable or cables adapting the port to standard USB-A</li> 2367 <li>it MUST implement the Android USB host API as documented in the Android 2368 SDK, and MUST declare support for the hardware feature 2369 <code>android.hardware.usb.host</code> [<a href="#resources53">Resources, 53</a>]</li> 2370 </ul> 2371 <p>Device implementations MUST implement the Android Debug Bridge. If a device 2372 implementation omits a USB client port, it MUST implement the Android Debug 2373 Bridge via local-area network (such as Ethernet or 802.11)</p> 2374 2375 <a name="section-8"></a><h2>8. Performance Compatibility</h2> 2376 <p>Device implementations MUST meet the key performance metrics of an Android 2377 4.2 compatible device defined in the table below:</p> 2378 <table><tbody><tr> 2379 <td><b>Metric</b></td> 2380 <td><b>Performance Threshold</b></td> 2381 <td><b>Comments</b></td> 2382 </tr> 2383 <tr> 2384 <td>Application Launch Time</td> 2385 <td>The following applications should launch within the specified time.<ul> 2386 <li>Browser: less than 1300ms</li> 2387 <li>Contacts: less than 700ms</li> 2388 <li>Settings: less than 700ms</li> 2389 </ul></td> 2390 <td>The launch time is measured as the total time to 2391 complete loading the default activity for the application, including the time 2392 it takes to start the Linux process, load the Android package into the Dalvik 2393 VM, and call onCreate.</td> 2394 </tr> 2395 <tr> 2396 <td>Simultaneous Applications</td> 2397 <td>When multiple applications have been launched, re-launching an 2398 already-running application after it has been launched must take less than the 2399 original launch time.</td> 2400 <td> </td> 2401 </tr> 2402 </tbody> 2403 </table> 2404 2405 <a name="section-9"></a><h2>9. Security Model Compatibility</h2> 2406 <p>Device implementations MUST implement a security model consistent with the 2407 Android platform security model as defined in Security and Permissions 2408 reference document in the APIs [<a href="#resources54">Resources, 54</a>] in the 2409 Android developer documentation. Device implementations MUST support 2410 installation of self-signed applications without requiring any additional 2411 permissions/certificates from any third parties/authorities. Specifically, 2412 compatible devices MUST support the security mechanisms described in the 2413 follow sub-sections.</p> 2414 <a name="section-9.1"></a><h3>9.1. Permissions</h3> 2415 <p>Device implementations MUST support the Android permissions model as 2416 defined in the Android developer documentation [<a 2417 href="#resources54">Resources, 54</a>]. Specifically, 2418 implementations MUST enforce each permission defined as described in the SDK 2419 documentation; no permissions may be omitted, altered, or ignored. 2420 Implementations MAY add additional permissions, provided the new permission ID 2421 strings are not in the android.* namespace.</p> 2422 <a name="section-9.2"></a><h3>9.2. UID and Process Isolation</h3> 2423 <p>Device implementations MUST support the Android application sandbox model, 2424 in which each application runs as a unique Unix-style UID and in a separate 2425 process. Device implementations MUST support running multiple applications as 2426 the same Linux user ID, provided that the applications are properly signed and 2427 constructed, as defined in the Security and Permissions reference [<a 2428 href="#resources54">Resources, 54</a>].</p> 2429 <a name="section-9.3"></a><h3>9.3. Filesystem Permissions</h3> 2430 <p>Device implementations MUST support the Android file access permissions 2431 model as defined in as defined in the Security and Permissions reference [<a 2432 href="#resources54">Resources, 54</a>].</p> 2433 <a name="section-9.4"></a><h3>9.4. Alternate Execution Environments</h3> 2434 <p>Device implementations MAY include runtime environments that execute 2435 applications using some other software or technology than the Dalvik virtual 2436 machine or native code. However, such alternate execution environments MUST 2437 NOT compromise the Android security model or the security of installed Android 2438 applications, as described in this section.</p> 2439 <p>Alternate runtimes MUST themselves be Android applications, and abide by 2440 the standard Android security model, as described elsewhere in Section 9.</p> 2441 <p>Alternate runtimes MUST NOT be granted access to resources protected by 2442 permissions not requested in the runtime's AndroidManifest.xml file via the 2443 <code><uses-permission></code> mechanism.</p> 2444 <p>Alternate runtimes MUST NOT permit applications to make use of features 2445 protected by Android permissions restricted to system applications.</p> 2446 <p>Alternate runtimes MUST abide by the Android sandbox model. Specifically:</p> 2447 <ul> 2448 <li>Alternate runtimes SHOULD install apps via the PackageManager into 2449 separate Android sandboxes (that is, Linux user IDs, etc.)</li> 2450 <li>Alternate runtimes MAY provide a single Android sandbox shared by all 2451 applications using the alternate runtime</li> 2452 <li>Alternate runtimes and installed applications using an alternate runtime 2453 MUST NOT reuse the sandbox of any other app installed on the device, except 2454 through the standard Android mechanisms of shared user ID and signing 2455 certificate</li> 2456 <li>Alternate runtimes MUST NOT launch with, grant, or be granted access to 2457 the sandboxes corresponding to other Android applications</li> 2458 </ul> 2459 <p>Alternate runtimes MUST NOT be launched with, be granted, or grant to other 2460 applications any privileges of the superuser (root), or of any other user ID.</p> 2461 <p>The .apk files of alternate runtimes MAY be included in the system image of 2462 a device implementation, but MUST be signed with a key distinct 2463 from the key used to sign other applications included with the device 2464 implementation.</p> 2465 <p>When installing applications, alternate runtimes MUST obtain user consent 2466 for the Android permissions used by the application. That is, if an 2467 application needs to make use of a device resource for which there is a 2468 corresponding Android permission (such as Camera, GPS, etc.), the alternate 2469 runtime MUST inform the user that the application will be able to access 2470 that resource. If the runtime environment does not record application 2471 capabilities in this manner, the runtime environment MUST list all 2472 permissions held by the runtime itself when installing any application 2473 using that runtime.</p> 2474 2475 <a name="section-9.5"></a><h3>9.5. Multi-User Support </h3> 2476 <p>Android 4.2 includes support for multiple users and provides support for full user isolation 2477 [<a href="#resources70">Resources, 70</a>].</p> 2478 <p>Device implementations MUST meet these requirements related to multi-user support[<a href="#resources71">Resources, 71</a>]:</p> 2479 <ul> 2480 <li>As the behavior of the telephony APIs on devices with multiple users is currently undefined, device implementations that 2481 declare android.hardware.telephony MUST NOT enable multi-user support. </li> 2482 <li>Device implementations MUST, for each user, implement a security model consistent with the Android platform security model 2483 as defined in Security and Permissions reference document in the APIs [Resources, 54]</li> 2484 </ul> 2485 </p> 2486 2487 <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. 2488 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. 2489 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 2490 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 2491 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 2492 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 2493 project includes an implementation that uses internal device storage for application external storage APIs; device implementations SHOULD use this configuration and software implementation. 2494 Device implementations that include multiple external storage paths MUST NOT allow Android applications to write to the secondary external storage</p> 2495 2496 <a name="section-9.6"></a><h3>9.6. Premium SMS Warning</h3> 2497 <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. 2498 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. 2499 The upstream Android open-source project provides an implementation that satisfies this requirement. 2500 </p> 2501 2502 <a name="section-10"></a><h2>10. Software Compatibility Testing</h2> 2503 <p>Device implementations MUST pass all tests described in this section.</p> 2504 <p>However, note that no software test package is fully comprehensive. For 2505 this reason, device implementers are very strongly encouraged to make the 2506 minimum number of changes as possible to the reference and preferred 2507 implementation of Android 4.2 available from the Android Open Source Project. 2508 This will minimize the risk of introducing bugs that create incompatibilities 2509 requiring rework and potential device updates.</p> 2510 <a name="section-10.1"></a><h3>10.1. Compatibility Test Suite</h3> 2511 <p>Device implementations MUST pass the Android Compatibility Test Suite (CTS) 2512 [<a href="#resources02">Resources, 2</a>] available from the Android Open Source 2513 Project, using the final shipping software on the device. Additionally, device 2514 implementers SHOULD use the reference implementation in the Android Open 2515 Source tree as much as possible, and MUST ensure compatibility in cases of 2516 ambiguity in CTS and for any reimplementations of parts of the reference 2517 source code.</p> 2518 <p>The CTS is designed to be run on an actual device. Like any software, the 2519 CTS may itself contain bugs. The CTS will be versioned independently of this 2520 Compatibility Definition, and multiple revisions of the CTS may be released 2521 for Android 4.2. Device implementations MUST pass the latest CTS version 2522 available at the time the device software is completed.</p> 2523 <a name="section-10.2"></a><h3>10.2. CTS Verifier</h3> 2524 <p>Device implementations MUST correctly execute all applicable cases in the 2525 CTS Verifier. The CTS Verifier is included with the Compatibility Test Suite, 2526 and is intended to be run by a human operator to test functionality that 2527 cannot be tested by an automated system, such as correct functioning of a 2528 camera and sensors.</p> 2529 <p>The CTS Verifier has tests for many kinds of hardware, including some 2530 hardware that is optional. Device implementations MUST pass all tests for 2531 hardware which they possess; for instance, if a device possesses an 2532 accelerometer, it MUST correctly execute the Accelerometer test case in the 2533 CTS Verifier. Test cases for features noted as optional by this Compatibility 2534 Definition Document MAY be skipped or omitted.</p> 2535 <p>Every device and every build MUST correctly run the CTS Verifier, as noted 2536 above. However, since many builds are very similar, device implementers are 2537 not expected to explicitly run the CTS Verifier on builds that differ only in 2538 trivial ways. Specifically, device implementations that differ from an 2539 implementation that has passed the CTS Verfier only by the set of included 2540 locales, branding, etc. MAY omit the CTS Verifier test.</p> 2541 <a name="section-10.3"></a><h3>10.3. Reference Applications</h3> 2542 <p>Device implementers MUST test implementation compatibility using the 2543 following open source applications:</p> 2544 <ul> 2545 <li>The "Apps for Android" applications [<a href="#resources55">Resources, 55</a>]</li> 2546 <li>Replica Island (available in Android Market)</li> 2547 </ul> 2548 <p>Each app above MUST launch and behave correctly on the implementation, for 2549 the implementation to be considered compatible.</p> 2550 2551 2552 <a name="section-11"></a><h2>11. Updatable Software</h2> 2553 <p>Device implementations MUST include a mechanism to replace the entirety of 2554 the system software. The mechanism need not perform "live" upgrades - that 2555 is, a device restart MAY be required.</p> 2556 <p>Any method can be used, provided that it can replace the entirety of the 2557 software preinstalled on the device. For instance, any of the following 2558 approaches will satisfy this requirement:</p> 2559 <ul> 2560 <li>Over-the-air (OTA) downloads with offline update via reboot</li> 2561 <li>"Tethered" updates over USB from a host PC</li> 2562 <li>"Offline" updates via a reboot and update from a file on removable 2563 storage</li> 2564 </ul> 2565 <p>The update mechanism used MUST support updates without wiping user data. 2566 That is, the update mechanism MUST preserve application private data 2567 and application shared data. Note that the upstream Android software includes 2568 an update mechanism that satisfies this requirement.</p> 2569 <p>If an error is found in a device implementation after it has been released 2570 but within its reasonable product lifetime that is determined in consultation 2571 with the Android Compatibility Team to affect the compatibility of third-party 2572 applications, the device implementer MUST correct the error via a software 2573 update available that can be applied per the mechanism just described.</p> 2574 2575 <a name="section-12"></a><h2>12. Contact Us</h2> 2576 <p>You can contact the document authors at <a 2577 href="mailto:compatibility (a] android.com">compatibility (a] android.com</a> for 2578 clarifications and to bring up any issues that you think the document does not 2579 cover.</p> 2580 2581 <div style="page-break-before: always;"></div> 2582 2583 <a name="appendix-A"></a><h2>Appendix A - Bluetooth Test Procedure</h2> 2584 <p>The Compatibility Test Suite includes cases that cover basic operation of 2585 the Android RFCOMM Bluetooth API. However, since Bluetooth is a communications 2586 protocol between devices, it cannot be fully tested by unit tests running on a 2587 single device. Consequently, device implementations MUST also pass the 2588 human-operated Bluetooth test procedure described below.</p> 2589 <p>The test procedure is based on the BluetoothChat sample app included in the 2590 Android open source project tree. The procedure requires two devices:</p> 2591 <ul> 2592 <li>a candidate device implementation running the software build to be tested</li> 2593 <li>a separate device implementation already known to be compatible, and of a 2594 model from the device implementation being tested - that is, a "known 2595 good" device implementation</li> 2596 </ul> 2597 <p>The test procedure below refers to these devices as the "candidate" and "known 2598 good" devices, respectively.</p> 2599 <h3>Setup and Installation</h3> 2600 <ol> 2601 <li>Build BluetoothChat.apk via 'make samples' from an Android source code tree</li> 2602 <li>Install BluetoothChat.apk on the known-good device</li> 2603 <li>Install BluetoothChat.apk on the candidate device</li> 2604 </ol> 2605 <h3>Test Bluetooth Control by Apps</h3> 2606 <ol> 2607 <li>Launch BluetoothChat on the candidate device, while Bluetooth is disabled</li> 2608 <li>Verify that the candidate device either turns on Bluetooth, or prompts the user with a dialog to turn on Bluetooth</li> 2609 </ol> 2610 <h3>Test Pairing and Communication</h3> 2611 <ol> 2612 <li>Launch the Bluetooth Chat app on both devices</li> 2613 <li>Make the known-good device discoverable from within BluetoothChat (using the Menu)</li> 2614 <li>On the candidate device, scan for Bluetooth devices from within BluetoothChat (using the Menu) and pair with the known-good device</li> 2615 <li>Send 10 or more messages from each device, and verify that the other device receives them correctly</li> 2616 <li>Close the BluetoothChat app on both devices by pressing <b>Home</b></li> 2617 <li>Unpair each device from the other, using the device Settings app</li> 2618 </ol> 2619 <h3>Test Pairing and Communication in the Reverse Direction</h3> 2620 <ol> 2621 <li>Launch the Bluetooth Chat app on both devices.</li> 2622 <li>Make the candidate device discoverable from within BluetoothChat (using the Menu).</li> 2623 <li>On the known-good device, scan for Bluetooth devices from within BluetoothChat (using the Menu) and pair with the candidate device.</li> 2624 <li>Send 10 or messages from each device, and verify that the other device receives them correctly.</li> 2625 <li>Close the Bluetooth Chat app on both devices by pressing Back repeatedly to get to the Launcher.</li> 2626 </ol> 2627 <h3>Test Re-Launches</h3> 2628 <ol> 2629 <li>Re-launch the Bluetooth Chat app on both devices.</li> 2630 <li>Send 10 or messages from each device, and verify that the other device receives them correctly.</li> 2631 </ol> 2632 <p>Note: the above tests have some cases which end a test section by using 2633 Home, and some using Back. These tests are not redundant and are not optional: 2634 the objective is to verify that the Bluetooth API and stack works correctly 2635 both when Activities are explicitly terminated (via the user pressing Back, 2636 which calls finish()), and implicitly sent to background (via the user 2637 pressing Home.) Each test sequence MUST be performed as described.</p> 2638 <div id="footerContent" xmlns:pdf="http://whatever"> 2639 <pdf:pagenumber/> 2640 </div> 2641 </body> 2642 </html> 2643
