/* * 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.view.accessibility.AccessibilityEvent; import android.view.accessibility.AccessibilityNodeInfo; import android.widget.RemoteViews.RemoteView; /** * 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: *
* ** 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 * } * }); * } * }* *
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:
* ** <Button * android:layout_height="wrap_content" * android:layout_width="wrap_content" * android:text="@string/self_destruct" * android:onClick="selfDestruct" />* *
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:
* ** public void selfDestruct(View view) { * // Kabloey * }* *
The {@link android.view.View} passed into the method is a reference to the widget * that was clicked.
* *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 state list drawable. * 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 State List * Drawable.
* *See the Buttons * guide.
* *XML attributes
** See {@link android.R.styleable#Button Button Attributes}, * {@link android.R.styleable#TextView TextView Attributes}, * {@link android.R.styleable#View View Attributes} *
*/ @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 defStyle) { super(context, attrs, defStyle); } @Override public void onInitializeAccessibilityEvent(AccessibilityEvent event) { super.onInitializeAccessibilityEvent(event); event.setClassName(Button.class.getName()); } @Override public void onInitializeAccessibilityNodeInfo(AccessibilityNodeInfo info) { super.onInitializeAccessibilityNodeInfo(info); info.setClassName(Button.class.getName()); } }