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/*
* 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;
/**
* A SeekBar is an extension of ProgressBar that adds a draggable thumb. The user can touch
* the thumb and drag left or right to set the current progress level or use the arrow keys.
* Placing focusable widgets to the left or right of a SeekBar is discouraged.
* <p>
* Clients of the SeekBar can attach a {@link SeekBar.OnSeekBarChangeListener} to
* be notified of the user's actions.
*
* @attr ref android.R.styleable#SeekBar_thumb
*/
public class SeekBar extends AbsSeekBar {
/**
* A callback that notifies clients when the progress level has been
* changed. This includes changes that were initiated by the user through a
* touch gesture or arrow key/trackball as well as changes that were initiated
* programmatically.
*/
public interface OnSeekBarChangeListener {
/**
* Notification that the progress level has changed. Clients can use the fromUser parameter
* to distinguish user-initiated changes from those that occurred programmatically.
*
* @param seekBar The SeekBar whose progress has changed
* @param progress The current progress level. This will be in the range 0..max where max
* was set by {@link ProgressBar#setMax(int)}. (The default value for max is 100.)
* @param fromUser True if the progress change was initiated by the user.
*/
void onProgressChanged(SeekBar seekBar, int progress, boolean fromUser);
/**
* Notification that the user has started a touch gesture. Clients may want to use this
* to disable advancing the seekbar.
* @param seekBar The SeekBar in which the touch gesture began
*/
void onStartTrackingTouch(SeekBar seekBar);
/**
* Notification that the user has finished a touch gesture. Clients may want to use this
* to re-enable advancing the seekbar.
* @param seekBar The SeekBar in which the touch gesture began
*/
void onStopTrackingTouch(SeekBar seekBar);
}
private OnSeekBarChangeListener mOnSeekBarChangeListener;
public SeekBar(Context context) {
this(context, null);
}
public SeekBar(Context context, AttributeSet attrs) {
this(context, attrs, com.android.internal.R.attr.seekBarStyle);
}
public SeekBar(Context context, AttributeSet attrs, int defStyle) {
super(context, attrs, defStyle);
}
@Override
void onProgressRefresh(float scale, boolean fromUser) {
super.onProgressRefresh(scale, fromUser);
if (mOnSeekBarChangeListener != null) {
mOnSeekBarChangeListener.onProgressChanged(this, getProgress(), fromUser);
}
}
/**
* Sets a listener to receive notifications of changes to the SeekBar's progress level. Also
* provides notifications of when the user starts and stops a touch gesture within the SeekBar.
*
* @param l The seek bar notification listener
*
* @see SeekBar.OnSeekBarChangeListener
*/
public void setOnSeekBarChangeListener(OnSeekBarChangeListener l) {
mOnSeekBarChangeListener = l;
}
@Override
void onStartTrackingTouch() {
super.onStartTrackingTouch();
if (mOnSeekBarChangeListener != null) {
mOnSeekBarChangeListener.onStartTrackingTouch(this);
}
}
@Override
void onStopTrackingTouch() {
super.onStopTrackingTouch();
if (mOnSeekBarChangeListener != null) {
mOnSeekBarChangeListener.onStopTrackingTouch(this);
}
}
@Override
public void onInitializeAccessibilityEvent(AccessibilityEvent event) {
super.onInitializeAccessibilityEvent(event);
event.setClassName(SeekBar.class.getName());
}
@Override
public void onInitializeAccessibilityNodeInfo(AccessibilityNodeInfo info) {
super.onInitializeAccessibilityNodeInfo(info);
info.setClassName(SeekBar.class.getName());
}
}
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