M7350/base/core/java/android/widget/Button.java
2024-09-09 08:52:07 +00:00

111 lines
4.1 KiB
Java

/*
* 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.util.Log;
import android.view.MotionEvent;
import android.view.KeyEvent;
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>
* &lt;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>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>
* 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 defStyle) {
super(context, attrs, defStyle);
}
}