| <p>This sample demonstrates how to create a live wallpaper and bundle it in an |
| <code>.apk</code> that users can install on their devices.</p> |
| |
| <p>In terms of implementation, a live wallpaper is very similar to a regular |
| Android <a href="../../../reference/android/app/Service.html">service</a>. The |
| only difference is the addition of a new method, <a |
| href="../../../reference/android/service/wallpaper/WallpaperService.html#onCreateEngine()"><code> |
| onCreateEngine()</code></a>, whose goal is to |
| create a <a |
| href="../../../reference/android/service/wallpaper/WallpaperService.Engine.html"> |
| <code>WallpaperService.Engine</code></a>. The engine is responsible for |
| handling the lifecycle and drawing of a wallpaper. The system provides a surface |
| on which you can draw, just like you would with a <a |
| href="../../../reference/android/view/SurfaceView.html"><code>SurfaceView</code></a>. |
| The wallpapers you create can respond to touch events on the screen and |
| have access to all the facilities of the platform: SGL (2D drawing), OpenGL (3D |
| drawing), GPS, accelerometers, network access, and so on. </p> |
| |
| <p>The examples in this application show how to set up a wallpaper service that |
| creates a <code>WallpaperService.Engine</code> to manage the service lifecycle, |
| render the wallpaper, handle touch events, and so on. The examples also show how |
| a wallpaper should stop drawing when its visibility changes, for example, when |
| the user launches an application that covers the home screen. Drawing only when |
| visible is an important implementation guideline for live wallpapers because it |
| minimizes the wallpaper's impact on system performance and battery life. |
| </p> |
| |
| <p>The application includes two wallpaper services and a wallpaper settings |
| activity:<p> |
| |
| <ul> |
| <li><a |
| href="src/com/example/android/livecubes/cube1/CubeWallpaper1.html"><code> |
| CubeWallpaper1</code></a> — a wallpaper service that draws and animates a |
| wire-frame cube to a <a |
| href="../../../reference/android/graphics/Canvas.html"><code>Canvas</code></a>. |
| </li> |
| <li><a |
| href="src/com/example/android/livecubes/cube2/CubeWallpaper2.html"><code>CubeWallpaper2</code></a> |
| — a wallpaper service that draws and animates a |
| wire-frame shape to a <code>Canvas</code>. The shape is set by the user, by means |
| of the <code>cube2.CubeWallpaper2Settings</code> settings activity (see below). The |
| wallpaper service implements a listener callback method that captures the user's |
| wallpaper shape preference. </li> |
| <li><a |
| href="src/com/example/android/livecubes/cube2/CubeWallpaper2Settings.html"><code>CubeWallpaper2Settings</code></a> |
| — a wallpaper service that draws and |
| animates a wire-frame shape to a <code>Canvas</code>. The shape is set by the |
| user through a simple settings activity, |
| <code>cube2.CubeWallpaper2Settings</code>, also included in the app. The |
| wallpaper service implements a listener callback method that captures the user's |
| wallpaper shape preference. </li> |
| </ul> |
| |
| <p>If you are developing a live wallpaper, remember that the feature is |
| supported only on Android 2.1 (API level 7) and higher versions of the platform. |
| To ensure that your application can only be installed on devices that support |
| live wallpapers, remember to add the following to the application's manifest |
| before publishing to Google Play:</p> |
| |
| <ul> |
| <li><code><uses-sdk android:minSdkVersion="7" /></code>, which indicates |
| to Google Play and the platform that your application requires Android 2.1 or |
| higher. For more information, see the <a href="../../../guide/appendix/api-levels.html">API Levels</a> |
| and the documentation for the |
| <a href="../../../guide/topics/manifest/uses-sdk-element.html"><code><uses-sdk></code></a> |
| element.</li> |
| <li><code><uses-feature android:name="android.software.live_wallpaper" /></code>, |
| which tells Google Play that your application includes a live wallpaper. |
| Google Play uses this feature as a filter, when presenting users lists of |
| available applications. When you declaring this feature, Google Play |
| displays your application only to users whose devices support live wallpapers, |
| while hiding it from other devices on which it would not be able to run. For |
| more information, see the documentation for the |
| <a href="../../../guide/topics/manifest/uses-feature-element.html"><code><uses-feature></code></a> |
| element.</li> |
| </ul> |
| |
| <p>For more information about live wallpapers, see the |
| <a href="../../articles/live-wallpapers.html">Live Wallpapers</a> article. </p> |
| |
| <img alt="Screenshot 1" src="../images/CubeLiveWallpaper1.png" /> |
| <img alt="Screenshot 3" src="../images/CubeLiveWallpaper3.png" /> |