content: /*
   * 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.annotation.UnsupportedAppUsage;
  import android.content.Context;
  import android.util.AttributeSet;
  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 min..max where min
           *                 and max were set by {@link ProgressBar#setMin(int)} and
           *                 {@link ProgressBar#setMax(int)}, respectively. (The default values for
           *                 min is 0 and 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);
      }
  
      @UnsupportedAppUsage
      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 defStyleAttr) {
          this(context, attrs, defStyleAttr, 0);
      }
  
      public SeekBar(Context context, AttributeSet attrs, int defStyleAttr, int defStyleRes) {
          super(context, attrs, defStyleAttr, defStyleRes);
      }
  
      @Override
      @UnsupportedAppUsage
      void onProgressRefresh(float scale, boolean fromUser, int progress) {
          super.onProgressRefresh(scale, fromUser, progress);
  
          if (mOnSeekBarChangeListener != null) {
              mOnSeekBarChangeListener.onProgressChanged(this, progress, 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 CharSequence getAccessibilityClassName() {
          return SeekBar.class.getName();
      }
  
      /** @hide */
      @Override
      public void onInitializeAccessibilityNodeInfoInternal(AccessibilityNodeInfo info) {
          super.onInitializeAccessibilityNodeInfoInternal(info);
  
          if (canUserSetProgress()) {
              info.addAction(AccessibilityNodeInfo.AccessibilityAction.ACTION_SET_PROGRESS);
          }
      }
  }
  