1/*
2 * Copyright (C) 2006 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 *      http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17package android.widget;
18
19import android.content.Context;
20import android.util.AttributeSet;
21import android.view.accessibility.AccessibilityEvent;
22import android.view.accessibility.AccessibilityNodeInfo;
23import android.widget.RemoteViews.RemoteView;
24
25
26/**
27 * Represents a push-button widget. Push-buttons can be
28 * pressed, or clicked, by the user to perform an action.
29
30 * <p>A typical use of a push-button in an activity would be the following:
31 * </p>
32 *
33 * <pre>
34 * public class MyActivity extends Activity {
35 *     protected void onCreate(Bundle icicle) {
36 *         super.onCreate(icicle);
37 *
38 *         setContentView(R.layout.content_layout_id);
39 *
40 *         final Button button = (Button) findViewById(R.id.button_id);
41 *         button.setOnClickListener(new View.OnClickListener() {
42 *             public void onClick(View v) {
43 *                 // Perform action on click
44 *             }
45 *         });
46 *     }
47 * }</pre>
48 *
49 * <p>However, instead of applying an {@link android.view.View.OnClickListener OnClickListener} to
50 * the button in your activity, you can assign a method to your button in the XML layout,
51 * using the {@link android.R.attr#onClick android:onClick} attribute. For example:</p>
52 *
53 * <pre>
54 * &lt;Button
55 *     android:layout_height="wrap_content"
56 *     android:layout_width="wrap_content"
57 *     android:text="@string/self_destruct"
58 *     android:onClick="selfDestruct" /&gt;</pre>
59 *
60 * <p>Now, when a user clicks the button, the Android system calls the activity's {@code
61 * selfDestruct(View)} method. In order for this to work, the method must be public and accept
62 * a {@link android.view.View} as its only parameter. For example:</p>
63 *
64 * <pre>
65 * public void selfDestruct(View view) {
66 *     // Kabloey
67 * }</pre>
68 *
69 * <p>The {@link android.view.View} passed into the method is a reference to the widget
70 * that was clicked.</p>
71 *
72 * <h3>Button style</h3>
73 *
74 * <p>Every Button is styled using the system's default button background, which is often different
75 * from one device to another and from one version of the platform to another. If you're not
76 * satisfied with the default button style and want to customize it to match the design of your
77 * application, then you can replace the button's background image with a <a
78 * href="{@docRoot}guide/topics/resources/drawable-resource.html#StateList">state list drawable</a>.
79 * A state list drawable is a drawable resource defined in XML that changes its image based on
80 * the current state of the button. Once you've defined a state list drawable in XML, you can apply
81 * it to your Button with the {@link android.R.attr#background android:background}
82 * attribute. For more information and an example, see <a
83 * href="{@docRoot}guide/topics/resources/drawable-resource.html#StateList">State List
84 * Drawable</a>.</p>
85 *
86 * <p>See the <a href="{@docRoot}guide/topics/ui/controls/button.html">Buttons</a>
87 * guide.</p>
88 *
89 * <p><strong>XML attributes</strong></p>
90 * <p>
91 * See {@link android.R.styleable#Button Button Attributes},
92 * {@link android.R.styleable#TextView TextView Attributes},
93 * {@link android.R.styleable#View View Attributes}
94 * </p>
95 */
96@RemoteView
97public class Button extends TextView {
98    public Button(Context context) {
99        this(context, null);
100    }
101
102    public Button(Context context, AttributeSet attrs) {
103        this(context, attrs, com.android.internal.R.attr.buttonStyle);
104    }
105
106    public Button(Context context, AttributeSet attrs, int defStyle) {
107        super(context, attrs, defStyle);
108    }
109
110    @Override
111    public void onInitializeAccessibilityEvent(AccessibilityEvent event) {
112        super.onInitializeAccessibilityEvent(event);
113        event.setClassName(Button.class.getName());
114    }
115
116    @Override
117    public void onInitializeAccessibilityNodeInfo(AccessibilityNodeInfo info) {
118        super.onInitializeAccessibilityNodeInfo(info);
119        info.setClassName(Button.class.getName());
120    }
121}
122