Button.java revision 6ec3d4f0dcc30879076fd3dd859de5005c045a43
19066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project/* 29066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project * Copyright (C) 2006 The Android Open Source Project 39066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project * 49066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project * Licensed under the Apache License, Version 2.0 (the "License"); 59066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project * you may not use this file except in compliance with the License. 69066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project * You may obtain a copy of the License at 79066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project * 89066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project * http://www.apache.org/licenses/LICENSE-2.0 99066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project * 109066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project * Unless required by applicable law or agreed to in writing, software 119066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project * distributed under the License is distributed on an "AS IS" BASIS, 129066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 139066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project * See the License for the specific language governing permissions and 149066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project * limitations under the License. 159066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project */ 169066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project 179066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Projectpackage android.widget; 189066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project 199066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Projectimport android.content.Context; 209066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Projectimport android.util.AttributeSet; 219066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Projectimport android.util.Log; 229066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Projectimport android.view.MotionEvent; 239066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Projectimport android.view.KeyEvent; 249066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Projectimport android.widget.RemoteViews.RemoteView; 259066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project 269066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project 279066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project/** 286ec3d4f0dcc30879076fd3dd859de5005c045a43Scott Main * Represents a push-button widget. Push-buttons can be 296ec3d4f0dcc30879076fd3dd859de5005c045a43Scott Main * pressed, or clicked, by the user to perform an action. 306ec3d4f0dcc30879076fd3dd859de5005c045a43Scott Main 316ec3d4f0dcc30879076fd3dd859de5005c045a43Scott Main * <p>A typical use of a push-button in an activity would be the following: 329066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project * </p> 339066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project * 346ec3d4f0dcc30879076fd3dd859de5005c045a43Scott Main * <pre> 359066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project * public class MyActivity extends Activity { 369066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project * protected void onCreate(Bundle icicle) { 379066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project * super.onCreate(icicle); 389066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project * 399066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project * setContentView(R.layout.content_layout_id); 409066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project * 419066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project * final Button button = (Button) findViewById(R.id.button_id); 429066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project * button.setOnClickListener(new View.OnClickListener() { 439066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project * public void onClick(View v) { 449066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project * // Perform action on click 459066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project * } 469066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project * }); 479066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project * } 486ec3d4f0dcc30879076fd3dd859de5005c045a43Scott Main * }</pre> 496ec3d4f0dcc30879076fd3dd859de5005c045a43Scott Main * 506ec3d4f0dcc30879076fd3dd859de5005c045a43Scott Main * <p>However, instead of applying an {@link android.view.View.OnClickListener OnClickListener} to 516ec3d4f0dcc30879076fd3dd859de5005c045a43Scott Main * the button in your activity, you can assign a method to your button in the XML layout, 526ec3d4f0dcc30879076fd3dd859de5005c045a43Scott Main * using the {@link android.R.attr#onClick android:onClick} attribute. For example:</p> 536ec3d4f0dcc30879076fd3dd859de5005c045a43Scott Main * 546ec3d4f0dcc30879076fd3dd859de5005c045a43Scott Main * <pre> 556ec3d4f0dcc30879076fd3dd859de5005c045a43Scott Main * <Button 566ec3d4f0dcc30879076fd3dd859de5005c045a43Scott Main * android:layout_height="wrap_content" 576ec3d4f0dcc30879076fd3dd859de5005c045a43Scott Main * android:layout_width="wrap_content" 586ec3d4f0dcc30879076fd3dd859de5005c045a43Scott Main * android:text="@string/self_destruct" 596ec3d4f0dcc30879076fd3dd859de5005c045a43Scott Main * android:onClick="selfDestruct" /></pre> 606ec3d4f0dcc30879076fd3dd859de5005c045a43Scott Main * 616ec3d4f0dcc30879076fd3dd859de5005c045a43Scott Main * <p>Now, when a user clicks the button, the Android system calls the activity's {@code 626ec3d4f0dcc30879076fd3dd859de5005c045a43Scott Main * selfDestruct(View)} method. In order for this to work, the method must be public and accept 636ec3d4f0dcc30879076fd3dd859de5005c045a43Scott Main * a {@link android.view.View} as its only parameter. For example:</p> 649066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project * 656ec3d4f0dcc30879076fd3dd859de5005c045a43Scott Main * <pre> 666ec3d4f0dcc30879076fd3dd859de5005c045a43Scott Main * public void selfDestruct(View view) { 676ec3d4f0dcc30879076fd3dd859de5005c045a43Scott Main * // Kabloey 686ec3d4f0dcc30879076fd3dd859de5005c045a43Scott Main * }</pre> 696ec3d4f0dcc30879076fd3dd859de5005c045a43Scott Main * 706ec3d4f0dcc30879076fd3dd859de5005c045a43Scott Main * <p>The {@link android.view.View} passed into the method is a reference to the widget 716ec3d4f0dcc30879076fd3dd859de5005c045a43Scott Main * that was clicked.</p> 726ec3d4f0dcc30879076fd3dd859de5005c045a43Scott Main * 736ec3d4f0dcc30879076fd3dd859de5005c045a43Scott Main * <h3>Button style</h3> 746ec3d4f0dcc30879076fd3dd859de5005c045a43Scott Main * 756ec3d4f0dcc30879076fd3dd859de5005c045a43Scott Main * <p>Every Button is styled using the system's default button background, which is often different 766ec3d4f0dcc30879076fd3dd859de5005c045a43Scott Main * from one device to another and from one version of the platform to another. If you're not 776ec3d4f0dcc30879076fd3dd859de5005c045a43Scott Main * satisfied with the default button style and want to customize it to match the design of your 786ec3d4f0dcc30879076fd3dd859de5005c045a43Scott Main * application, then you can replace the button's background image with a <a 796ec3d4f0dcc30879076fd3dd859de5005c045a43Scott Main * href="{@docRoot}guide/topics/resources/drawable-resource.html#StateList">state list drawable</a>. 806ec3d4f0dcc30879076fd3dd859de5005c045a43Scott Main * A state list drawable is a drawable resource defined in XML that changes its image based on 816ec3d4f0dcc30879076fd3dd859de5005c045a43Scott Main * the current state of the button. Once you've defined a state list drawable in XML, you can apply 826ec3d4f0dcc30879076fd3dd859de5005c045a43Scott Main * it to your Button with the {@link android.R.attr#background android:background} 836ec3d4f0dcc30879076fd3dd859de5005c045a43Scott Main * attribute. For more information and an example, see <a 846ec3d4f0dcc30879076fd3dd859de5005c045a43Scott Main * href="{@docRoot}guide/topics/resources/drawable-resource.html#StateList">State List 856ec3d4f0dcc30879076fd3dd859de5005c045a43Scott Main * Drawable</a>.</p> 866ec3d4f0dcc30879076fd3dd859de5005c045a43Scott Main * 876ec3d4f0dcc30879076fd3dd859de5005c045a43Scott Main * <p>Also see the <a href="{@docRoot}resources/tutorials/views/hello-formstuff.html">Form Stuff 886ec3d4f0dcc30879076fd3dd859de5005c045a43Scott Main * tutorial</a> for an example implementation of a button.</p> 8941ec65355bd6ded652769725b276d47c54a0d913Scott Main * 909066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project * <p><strong>XML attributes</strong></p> 916ec3d4f0dcc30879076fd3dd859de5005c045a43Scott Main * <p> 926ec3d4f0dcc30879076fd3dd859de5005c045a43Scott Main * See {@link android.R.styleable#Button Button Attributes}, 936ec3d4f0dcc30879076fd3dd859de5005c045a43Scott Main * {@link android.R.styleable#TextView TextView Attributes}, 949066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project * {@link android.R.styleable#View View Attributes} 959066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project * </p> 969066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project */ 979066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project@RemoteView 989066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Projectpublic class Button extends TextView { 999066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project public Button(Context context) { 1009066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project this(context, null); 1019066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project } 1029066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project 1039066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project public Button(Context context, AttributeSet attrs) { 1049066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project this(context, attrs, com.android.internal.R.attr.buttonStyle); 1059066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project } 1069066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project 1079066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project public Button(Context context, AttributeSet attrs, int defStyle) { 1089066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project super(context, attrs, defStyle); 1099066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project } 1109066cfe9886ac131c34d59ed0e2d287b0e3c0087The Android Open Source Project} 111