content: /*
   * Copyright (C) 2012 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.android.launcher3;
  
  import android.animation.Animator;
  import android.animation.AnimatorSet;
  import android.animation.ObjectAnimator;
  import android.animation.PropertyValuesHolder;
  import android.animation.ValueAnimator;
  import android.graphics.drawable.Drawable;
  import android.util.Property;
  import android.view.View;
  import android.view.ViewTreeObserver;
  
  import java.util.HashSet;
  import java.util.WeakHashMap;
  
  public class LauncherAnimUtils {
      static WeakHashMap<Animator, Object> sAnimators = new WeakHashMap<Animator, Object>();
      static Animator.AnimatorListener sEndAnimListener = new Animator.AnimatorListener() {
          public void onAnimationStart(Animator animation) {
              sAnimators.put(animation, null);
          }
  
          public void onAnimationRepeat(Animator animation) {
          }
  
          public void onAnimationEnd(Animator animation) {
              sAnimators.remove(animation);
          }
  
          public void onAnimationCancel(Animator animation) {
              sAnimators.remove(animation);
          }
      };
  
      public static void cancelOnDestroyActivity(Animator a) {
          a.addListener(sEndAnimListener);
      }
  
      // Helper method. Assumes a draw is pending, and that if the animation's duration is 0
      // it should be cancelled
      public static void startAnimationAfterNextDraw(final Animator animator, final View view) {
          view.getViewTreeObserver().addOnDrawListener(new ViewTreeObserver.OnDrawListener() {
              private boolean mStarted = false;
  
              public void onDraw() {
                  if (mStarted) return;
                  mStarted = true;
                  // Use this as a signal that the animation was cancelled
                  if (animator.getDuration() == 0) {
                      return;
                  }
                  animator.start();
  
                  final ViewTreeObserver.OnDrawListener listener = this;
                  view.post(new Runnable() {
                      public void run() {
                          view.getViewTreeObserver().removeOnDrawListener(listener);
                      }
                  });
              }
          });
      }
  
      public static void onDestroyActivity() {
          HashSet<Animator> animators = new HashSet<Animator>(sAnimators.keySet());
          for (Animator a : animators) {
              if (a.isRunning()) {
                  a.cancel();
              }
              sAnimators.remove(a);
          }
      }
  
      public static AnimatorSet createAnimatorSet() {
          AnimatorSet anim = new AnimatorSet();
          cancelOnDestroyActivity(anim);
          return anim;
      }
  
      public static ValueAnimator ofFloat(float... values) {
          ValueAnimator anim = new ValueAnimator();
          anim.setFloatValues(values);
          cancelOnDestroyActivity(anim);
          return anim;
      }
  
      public static ObjectAnimator ofFloat(View target, Property<View, Float> property,
              float... values) {
          ObjectAnimator anim = ObjectAnimator.ofFloat(target, property, values);
          cancelOnDestroyActivity(anim);
          new FirstFrameAnimatorHelper(anim, target);
          return anim;
      }
  
      public static ObjectAnimator ofViewAlphaAndScale(View target,
              float alpha, float scaleX, float scaleY) {
          return ofPropertyValuesHolder(target,
                  PropertyValuesHolder.ofFloat(View.ALPHA, alpha),
                  PropertyValuesHolder.ofFloat(View.SCALE_X, scaleX),
                  PropertyValuesHolder.ofFloat(View.SCALE_Y, scaleY));
      }
  
      public static ObjectAnimator ofPropertyValuesHolder(View target,
              PropertyValuesHolder... values) {
          return ofPropertyValuesHolder(target, target, values);
      }
  
      public static ObjectAnimator ofPropertyValuesHolder(Object target,
              View view, PropertyValuesHolder... values) {
          ObjectAnimator anim = ObjectAnimator.ofPropertyValuesHolder(target, values);
          cancelOnDestroyActivity(anim);
          new FirstFrameAnimatorHelper(anim, view);
          return anim;
      }
  
      public static final Property<Drawable, Integer> DRAWABLE_ALPHA =
              new Property<Drawable, Integer>(Integer.TYPE, "drawableAlpha") {
                  @Override
                  public Integer get(Drawable drawable) {
                      return drawable.getAlpha();
                  }
  
                  @Override
                  public void set(Drawable drawable, Integer alpha) {
                      drawable.setAlpha(alpha);
                  }
              };
  }
  