1 page.title=Handling Features Not Supported on TV 2 parent.title=Designing for TV 3 parent.link=index.html 4 5 trainingnavtop=true 6 previous.title=Optimizing Navigation for TV 7 previous.link=optimizing-navigation-tv.html 8 9 @jd:body 10 11 <div id="tb-wrapper"> 12 <div id="tb"> 13 14 <h2>This lesson teaches you to</h2> 15 <ol> 16 <li><a href="#WorkaroundUnsupportedFeatures">Work Around Features Not Supported on TV</a></li> 17 <li><a href="#CheckAvailableFeatures">Check for Available Features at Runtime</a></li> 18 </ol> 19 20 </div> 21 </div> 22 23 <p> 24 TVs are much different from other Android-powered devices: 25 </p> 26 <ul> 27 <li>They're not mobile.</li> 28 <li>Out of habit, people use them for watching media with little or no interaction.</li> 29 <li>People interact with them from a distance.</li> 30 </ul> 31 32 <p> 33 Because TVs have a different purpose from other devices, they usually don't have hardware features 34 that other Android-powered devices often have. For this reason, the Android system does not 35 support the following features for a TV device: 36 <table> 37 <tr> 38 <th>Hardware</th> 39 <th>Android feature descriptor</th> 40 </tr> 41 <tr> 42 <td>Camera</td> 43 <td>android.hardware.camera</td> 44 </tr> 45 <tr> 46 <td>GPS</td> 47 <td>android.hardware.location.gps</td> 48 </tr> 49 <tr> 50 <td>Microphone</td> 51 <td>android.hardware.microphone</td> 52 </tr> 53 <tr> 54 <td>Near Field Communications (NFC)</td> 55 <td>android.hardware.nfc</td> 56 </tr> 57 <tr> 58 <td>Telephony</td> 59 <td>android.hardware.telephony</td> 60 </tr> 61 <tr> 62 <td>Touchscreen</td> 63 <td>android.hardware.touchscreen</td> 64 </tr> 65 </table> 66 </p> 67 68 <p> 69 This lesson shows you how to work around features that are not available on TV by: 70 <ul> 71 <li>Providing work arounds for some non-supported features.</li> 72 <li>Checking for available features at runtime and conditionally activating/deactivating certain code 73 paths based on availability of those features.</li> 74 </ul> 75 </p> 76 77 78 <h2 id="WorkaroundUnsupportedFeatures">Work Around Features Not Supported on TV</h2> 79 80 <p> 81 Android doesn't support touchscreen interaction for TV devices, most TVs don't have touch screens, 82 and interacting with a TV using a touchscreen is not consistent with the 10 foot environment. For 83 these reasons, users interact with Android-powered TVs using a remote. In consideration of this, 84 ensure that every control in your app can be accessed with the D-pad. Refer back to the previous two lessons 85 <a href="{@docRoot}training/tv/optimizing-layouts-tv.html">Optimizing Layouts for TV</a> and 86 <a href="{@docRoot}training/tv/optimizing-navigation-tv.html">Optimize Navigation for TV</a> for 87 more details 88 on this topic. The Android system assumes that a device has a touchscreen, so if you want your application 89 to run on a TV, you must <strong>explicitly</strong> disable the touchscreen requirement in your manifest file: 90 <pre> 91 <uses-feature android:name="android.hardware.touchscreen" android:required="false"/> 92 </pre> 93 </p> 94 95 <p> 96 Although a TV doesn't have a camera, you can still provide a photography-related application on a TV. 97 For example, if you have an app that takes, views and edits photos, you can disable its picture-taking 98 functionality for TVs and still allow users to view and even edit photos. The next section talks about how to 99 deactivate or activate specific functions in the application based on runtime device type detection. 100 </p> 101 102 <p> 103 Because TVs are stationary, indoor devices, they don't have built-in GPS. If your application uses location 104 information, allow users to search for a location or use a "static" location provider to get 105 a location from the zip code configured during the TV setup. 106 <pre> 107 LocationManager locationManager = (LocationManager) this.getSystemService(Context.LOCATION_SERVICE); 108 Location location = locationManager.getLastKnownLocation("static"); 109 Geocoder geocoder = new Geocoder(this); 110 Address address = null; 111 112 try { 113 address = geocoder.getFromLocation(location.getLatitude(), location.getLongitude(), 1).get(0); 114 Log.d("Zip code", address.getPostalCode()); 115 116 } catch (IOException e) { 117 Log.e(TAG, "Geocoder error", e); 118 } 119 </pre> 120 </p> 121 122 <p> 123 TVs usually don't support microphones, but if you have an application that uses voice control, 124 you can create a mobile device app that takes voice input and then acts as a remote control for a TV. 125 </p> 126 127 <h2 id="CheckAvailableFeatures">Check for Available Features at Runtime</h2> 128 129 <p> 130 To check if a feature is available at runtime, call 131 {@link android.content.pm.PackageManager#hasSystemFeature(String)}. 132 This method takes a single argument : a string corresponding to the 133 feature you want to check. For example, to check for touchscreen, use 134 {@link android.content.pm.PackageManager#hasSystemFeature(String)} with the argument 135 {@link android.content.pm.PackageManager#FEATURE_TOUCHSCREEN}. 136 </p> 137 138 <p> 139 The following code snippet demonstrates how to detect device type at runtime based on supported features: 140 141 <pre> 142 // Check if android.hardware.telephony feature is available. 143 if (getPackageManager().hasSystemFeature("android.hardware.telephony")) { 144 Log.d("Mobile Test", "Running on phone"); 145 // Check if android.hardware.touchscreen feature is available. 146 } else if (getPackageManager().hasSystemFeature("android.hardware.touchscreen")) { 147 Log.d("Tablet Test", "Running on devices that don't support telphony but have a touchscreen."); 148 } else { 149 Log.d("TV Test", "Running on a TV!"); 150 } 151 </pre> 152 </p> 153 154 <p> 155 This is just one example of using runtime checks to deactivate app functionality that depends on features 156 that aren't available on TVs. 157 </p>
