/* * Copyright (C) 2006 The Android Open Source Project * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ package android.widget; import android.content.Context; import android.util.AttributeSet; import android.widget.RemoteViews.RemoteView; /** * 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> * public class MyActivity extends Activity { * protected void onCreate(Bundle icicle) { * super.onCreate(icicle); * * setContentView(R.layout.content_layout_id); * * final Button button = (Button) findViewById(R.id.button_id); * button.setOnClickListener(new View.OnClickListener() { * public void onClick(View v) { * // Perform action on click * } * }); * } * }</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" /></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}guide/topics/ui/controls/button.html">Buttons</a> * guide.</p> * * <p><strong>XML attributes</strong></p> * <p> * See {@link android.R.styleable#Button Button Attributes}, * {@link android.R.styleable#TextView TextView Attributes}, * {@link android.R.styleable#View View Attributes} * </p> */ @RemoteView public class Button extends TextView { public Button(Context context) { this(context, null); } public Button(Context context, AttributeSet attrs) { this(context, attrs, com.android.internal.R.attr.buttonStyle); } public Button(Context context, AttributeSet attrs, int defStyleAttr) { this(context, attrs, defStyleAttr, 0); } public Button(Context context, AttributeSet attrs, int defStyleAttr, int defStyleRes) { super(context, attrs, defStyleAttr, defStyleRes); } @Override public CharSequence getAccessibilityClassName() { return Button.class.getName(); } }