content: /*
   * Copyright (C) 2013 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 com.lb.launcher;
  
  import android.support.v4.widget.AutoScrollHelper;
  import android.widget.ScrollView;
  
  /**
   * An implementation of {@link AutoScrollHelper} that knows how to scroll
   * through a {@link Folder}.
   */
  public class FolderAutoScrollHelper extends AutoScrollHelper {
      private static final float MAX_SCROLL_VELOCITY = 1500f;
  
      private final ScrollView mTarget;
  
      public FolderAutoScrollHelper(ScrollView target) {
          super(target);
  
          mTarget = target;
  
          setActivationDelay(0);
          setEdgeType(EDGE_TYPE_INSIDE_EXTEND);
          setExclusive(true);
          setMaximumVelocity(MAX_SCROLL_VELOCITY, MAX_SCROLL_VELOCITY);
          setRampDownDuration(0);
          setRampUpDuration(0);
      }
  
      @Override
      public void scrollTargetBy(int deltaX, int deltaY) {
          mTarget.scrollBy(deltaX, deltaY);
      }
  
      @Override
      public boolean canTargetScrollHorizontally(int direction) {
          // List do not scroll horizontally.
          return false;
      }
  
      @Override
      public boolean canTargetScrollVertically(int direction) {
          return mTarget.canScrollVertically(direction);
      }
  }