| <body> |
| <p>Android allows applications to publish views to be embedded in other applications. These |
| views are called gadgets, and are published by "gadget providers." The component that can |
| contain gadgets is called a "gadget host." |
| </p> |
| <h3><a href="package-descr.html#providers">Gadget Providers</a></h3> |
| <ul> |
| <li><a href="package-descr.html#provider_manifest">Declaring a gadget in the AndroidManifest</a></li> |
| <li><a href="package-descr.html#provider_meta_data">Adding the GadgetProviderInfo meta-data</a></li> |
| <li><a href="package-descr.html#provider_GadgetProvider">Using the GadgetProvider class</a></li> |
| <li><a href="package-descr.html#provider_configuration">Gadget Configuration UI</a></li> |
| <li><a href="package-descr.html#provider_broadcasts">Gadget Broadcast Intents</a></li> |
| </ul> |
| <h3><a href="package-descr.html#">Gadget Hosts</a></h3> |
| |
| |
| {@more} |
| |
| |
| <h2><a name="providers"></a>Gadget Providers</h2> |
| <p> |
| Any application can publish gadgets. All an application needs to do to publish a gadget is |
| to have a {@link android.content.BroadcastReceiver} that receives the {@link |
| android.gadget.GadgetManager#ACTION_GADGET_UPDATE GadgetManager.ACTION_GADGET_UPDATE} intent, |
| and provide some meta-data about the gadget. Android provides the |
| {@link android.gadget.GadgetProvider} class, which extends BroadcastReceiver, as a convenience |
| class to aid in handling the broadcasts. |
| |
| <h3><a name="provider_manifest"></a>Declaring a gadget in the AndroidManifest</h3> |
| |
| <p> |
| First, declare the {@link android.content.BroadcastReceiver} in your application's |
| <code>AndroidManifest.xml</code> file. |
| |
| {@sample frameworks/base/tests/gadgets/GadgetHostTest/AndroidManifest.xml GadgetProvider} |
| |
| <p> |
| The <b><code><receiver></b> element has the following attributes: |
| <ul> |
| <li><b><code>android:name</code> -</b> which specifies the |
| {@link android.content.BroadcastReceiver} or {@link android.gadget.GadgetProvider} |
| class.</li> |
| <li><b><code>android:label</code> -</b> which specifies the string resource that |
| will be shown by the gadget picker as the label.</li> |
| <li><b><code>android:icon</code> -</b> which specifies the drawable resource that |
| will be shown by the gadget picker as the icon.</li> |
| </ul> |
| |
| <p> |
| The <b><code><intent-filter></b> element tells the {@link android.content.pm.PackageManager} |
| that this {@link android.content.BroadcastReceiver} receives the {@link |
| android.gadget.GadgetManager#ACTION_GADGET_UPDATE GadgetManager.ACTION_GADGET_UPDATE} broadcast. |
| The gadget manager will send other broadcasts directly to your gadget provider as required. |
| It is only necessary to explicitly declare that you accept the {@link |
| android.gadget.GadgetManager#ACTION_GADGET_UPDATE GadgetManager.ACTION_GADGET_UPDATE} broadcast. |
| |
| <p> |
| The <b><code><meta-data></code></b> element tells the gadget manager which xml resource to |
| read to find the {@link android.gadget.GadgetProviderInfo} for your gadget provider. It has the following |
| attributes: |
| <ul> |
| <li><b><code>android:name="android.gadget.provider"</code> -</b> identifies this meta-data |
| as the {@link android.gadget.GadgetProviderInfo} descriptor.</li> |
| <li><b><code>android:resource</code> -</b> is the xml resource to use as that descriptor.</li> |
| </ul> |
| |
| |
| <h3><a name="provider_meta_data"></a>Adding the {@link android.gadget.GadgetProviderInfo GadgetProviderInfo} meta-data</h3> |
| |
| <p> |
| For a gadget, the values in the {@link android.gadget.GadgetProviderInfo} structure are supplied |
| in an XML resource. In the example above, the xml resource is referenced with |
| <code>android:resource="@xml/gadget_info"</code>. That XML file would go in your application's |
| directory at <code>res/xml/gadget_info.xml</code>. Here is a simple example. |
| |
| {@sample frameworks/base/tests/gadgets/GadgetHostTest/res/xml/gadget_info.xml GadgetProviderInfo} |
| |
| <p> |
| The attributes are as documented in the {@link android.gadget.GadgetProviderInfo GagetInfo} class. (86400000 milliseconds means once per day) |
| |
| |
| <h3><a name="provider_GadgetProvider"></a>Using the {@link android.gadget.GadgetProvider GadgetProvider} class</h3> |
| |
| <p>The GadgetProvider class is the easiest way to handle the gadget provider intent broadcasts. |
| See the <code>src/com/example/android/apis/gadget/ExampleGadgetProvider.java</code> |
| sample class in ApiDemos for an example. |
| |
| <p class="note">Keep in mind that since the the GadgetProvider is a BroadcastReceiver, |
| your process is not guaranteed to keep running after the callback methods return. See |
| <a href="../../../guide/topics/fundamentals.html#broadlife">Application Fundamentals > |
| Broadcast Receiver Lifecycle</a> for more information. |
| |
| |
| |
| <h3><a name="provider_configuration"></a>Gadget Configuration UI</h3> |
| |
| <p> |
| Gadget hosts have the ability to start a configuration activity when a gadget is instantiated. |
| The activity should be declared as normal in AndroidManifest.xml, and it should be listed in |
| the GadgetProviderInfo XML file in the <code>android:configure</code> attribute. |
| |
| <p>The activity you specified will be launched with the {@link |
| android.gadget.GadgetManager#ACTION_GADGET_CONFIGURE} action. See the documentation for that |
| action for more info. |
| |
| <p>See the <code>src/com/example/android/apis/gadget/ExampleGadgetConfigure.java</code> |
| sample class in ApiDemos for an example. |
| |
| |
| |
| <h3><a name="providers_broadcasts"></a>Gadget Broadcast Intents</h3> |
| |
| <p>{@link android.gadget.GadgetProvider} is just a convenience class. If you would like |
| to receive the gadget broadcasts directly, you can. The four intents you need to care about are: |
| <ul> |
| <li>{@link android.gadget.GadgetManager#ACTION_GADGET_UPDATE}</li> |
| <li>{@link android.gadget.GadgetManager#ACTION_GADGET_DELETED}</li> |
| <li>{@link android.gadget.GadgetManager#ACTION_GADGET_ENABLED}</li> |
| <li>{@link android.gadget.GadgetManager#ACTION_GADGET_DISABLED}</li> |
| </ul> |
| |
| <p>By way of example, the implementation of |
| {@link android.gadget.GadgetProvider#onReceive} is quite simple:</p> |
| |
| {@sample frameworks/base/core/java/android/gadget/GadgetProvider.java onReceive} |
| |
| |
| <h2>Gadget Hosts</h3> |
| <p>Gadget hosts are the containers in which gadgets can be placed. Most of the look and feel |
| details are left up to the gadget hosts. For example, the home screen has one way of viewing |
| gadgets, but the lock screen could also contain gadgets, and it would have a different way of |
| adding, removing and otherwise managing gadgets.</p> |
| <p>For more information on implementing your own gadget host, see the |
| {@link android.gadget.GadgetHost GadgetHost} class.</p> |
| </body> |
| |