Merge "docs: add more info about state list drawable and onclick attribute to...

/**

 * <p>

 * <code>Button</code> represents a push-button widget. Push-buttons can be

 * pressed, or clicked, by the user to perform an action. A typical use of a

 * push-button in an activity would be the following:

 * Represents a push-button widget. Push-buttons can be

 * pressed, or clicked, by the user to perform an action.

 * <p>A typical use of a push-button in an activity would be the following:

 * </p>

 *

 * <pre class="prettyprint">

 * <pre>

 * public class MyActivity extends Activity {

 *     protected void onCreate(Bundle icicle) {

 *         super.onCreate(icicle);

 *             }

 *         });

 *     }

 * }

 * </pre>

 * }</pre>

 *

 * <p>However, instead of applying an {@link android.view.View.OnClickListener OnClickListener} to

 * the button in your activity, you can assign a method to your button in the XML layout,

 * using the {@link android.R.attr#onClick android:onClick} attribute. For example:</p>

 *

 * <pre>

 * <Button

 *     android:layout_height="wrap_content"

 *     android:layout_width="wrap_content"

 *     android:text="@string/self_destruct"

 *     android:onClick="selfDestruct" /&gt;</pre>

 *

 * <p>Now, when a user clicks the button, the Android system calls the activity's {@code

 * selfDestruct(View)} method. In order for this to work, the method must be public and accept

 * a {@link android.view.View} as its only parameter. For example:</p>

 *

 * <pre>

 * public void selfDestruct(View view) {

 *     // Kabloey

 * }</pre>

 *

 * <p>The {@link android.view.View} passed into the method is a reference to the widget

 * that was clicked.</p>

 *

 * <h3>Button style</h3>

 *

 * <p>Every Button is styled using the system's default button background, which is often different

 * from one device to another and from one version of the platform to another. If you're not

 * satisfied with the default button style and want to customize it to match the design of your

 * application, then you can replace the button's background image with a <a

 * href="{@docRoot}guide/topics/resources/drawable-resource.html#StateList">state list drawable</a>.

 * A state list drawable is a drawable resource defined in XML that changes its image based on

 * the current state of the button. Once you've defined a state list drawable in XML, you can apply

 * it to your Button with the {@link android.R.attr#background android:background}

 * attribute. For more information and an example, see <a

 * href="{@docRoot}guide/topics/resources/drawable-resource.html#StateList">State List

 * Drawable</a>.</p>

 *

 * <p>See the <a href="{@docRoot}resources/tutorials/views/hello-formstuff.html">Form Stuff

 * tutorial</a>.</p>

 * <p>Also see the <a href="{@docRoot}resources/tutorials/views/hello-formstuff.html">Form Stuff

 * tutorial</a> for an example implementation of a button.</p>

 *

 * <p><strong>XML attributes</strong></p>

 * <p>

</selector>

</pre>

<p>This layout XML applies the drawable to a View:</p>

<p>This layout XML applies the state list drawable to a Button:</p>

<pre>

<ImageView

<Button

    android:layout_height="wrap_content"

    android:layout_width="wrap_content"

    android:src="@drawable/button" />

    android:background="@drawable/button" />

</pre>

</dd> <!-- end example -->