2 * Copyright (C) 2006 The Android Open Source Project
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
8 * http://www.apache.org/licenses/LICENSE-2.0
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.
17 package android.widget;
19 import android.content.Context;
20 import android.util.AttributeSet;
21 import android.view.accessibility.AccessibilityEvent;
22 import android.view.accessibility.AccessibilityNodeInfo;
27 * A SeekBar is an extension of ProgressBar that adds a draggable thumb. The user can touch
28 * the thumb and drag left or right to set the current progress level or use the arrow keys.
29 * Placing focusable widgets to the left or right of a SeekBar is discouraged.
31 * Clients of the SeekBar can attach a {@link SeekBar.OnSeekBarChangeListener} to
32 * be notified of the user's actions.
34 * @attr ref android.R.styleable#SeekBar_thumb
36 public class SeekBar extends AbsSeekBar {
39 * A callback that notifies clients when the progress level has been
40 * changed. This includes changes that were initiated by the user through a
41 * touch gesture or arrow key/trackball as well as changes that were initiated
44 public interface OnSeekBarChangeListener {
47 * Notification that the progress level has changed. Clients can use the fromUser parameter
48 * to distinguish user-initiated changes from those that occurred programmatically.
50 * @param seekBar The SeekBar whose progress has changed
51 * @param progress The current progress level. This will be in the range 0..max where max
52 * was set by {@link ProgressBar#setMax(int)}. (The default value for max is 100.)
53 * @param fromUser True if the progress change was initiated by the user.
55 void onProgressChanged(SeekBar seekBar, int progress, boolean fromUser);
58 * Notification that the user has started a touch gesture. Clients may want to use this
59 * to disable advancing the seekbar.
60 * @param seekBar The SeekBar in which the touch gesture began
62 void onStartTrackingTouch(SeekBar seekBar);
65 * Notification that the user has finished a touch gesture. Clients may want to use this
66 * to re-enable advancing the seekbar.
67 * @param seekBar The SeekBar in which the touch gesture began
69 void onStopTrackingTouch(SeekBar seekBar);
72 private OnSeekBarChangeListener mOnSeekBarChangeListener;
74 public SeekBar(Context context) {
78 public SeekBar(Context context, AttributeSet attrs) {
79 this(context, attrs, com.android.internal.R.attr.seekBarStyle);
82 public SeekBar(Context context, AttributeSet attrs, int defStyle) {
83 super(context, attrs, defStyle);
87 void onProgressRefresh(float scale, boolean fromUser) {
88 super.onProgressRefresh(scale, fromUser);
90 if (mOnSeekBarChangeListener != null) {
91 mOnSeekBarChangeListener.onProgressChanged(this, getProgress(), fromUser);
96 * Sets a listener to receive notifications of changes to the SeekBar's progress level. Also
97 * provides notifications of when the user starts and stops a touch gesture within the SeekBar.
99 * @param l The seek bar notification listener
101 * @see SeekBar.OnSeekBarChangeListener
103 public void setOnSeekBarChangeListener(OnSeekBarChangeListener l) {
104 mOnSeekBarChangeListener = l;
108 void onStartTrackingTouch() {
109 super.onStartTrackingTouch();
110 if (mOnSeekBarChangeListener != null) {
111 mOnSeekBarChangeListener.onStartTrackingTouch(this);
116 void onStopTrackingTouch() {
117 super.onStopTrackingTouch();
118 if (mOnSeekBarChangeListener != null) {
119 mOnSeekBarChangeListener.onStopTrackingTouch(this);
124 public void onInitializeAccessibilityEvent(AccessibilityEvent event) {
125 super.onInitializeAccessibilityEvent(event);
126 event.setClassName(SeekBar.class.getName());
130 public void onInitializeAccessibilityNodeInfo(AccessibilityNodeInfo info) {
131 super.onInitializeAccessibilityNodeInfo(info);
132 info.setClassName(SeekBar.class.getName());