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.android.bitmap.drawable;
  
  import android.animation.ValueAnimator;
  import android.animation.ValueAnimator.AnimatorUpdateListener;
  import android.graphics.Canvas;
  import android.graphics.ColorFilter;
  import android.graphics.Paint;
  import android.graphics.Rect;
  import android.graphics.drawable.Drawable;
  
  import com.android.bitmap.drawable.ExtendedBitmapDrawable.ExtendedOptions;
  
  /**
   * A drawable that wraps another drawable and places it in the center of this space. This drawable
   * allows a background color for the "tile", and has a fade-out transition when
   * {@link #setVisible(boolean, boolean)} indicates that it is no longer visible.
   */
  public class TileDrawable extends Drawable implements Drawable.Callback {
  
      private final ExtendedOptions mOpts;
      private final Paint mPaint = new Paint();
      private final Drawable mInner;
      private final int mInnerWidth;
      private final int mInnerHeight;
  
      protected final ValueAnimator mFadeOutAnimator;
  
      public TileDrawable(Drawable inner, int innerWidth, int innerHeight, int fadeOutDurationMs,
              ExtendedOptions opts) {
          mOpts = opts;
          mInner = inner != null ? inner.mutate() : null;
          mInnerWidth = innerWidth;
          mInnerHeight = innerHeight;
          if (inner != null) {
              mInner.setCallback(this);
          }
  
          mFadeOutAnimator = ValueAnimator.ofInt(255, 0)
                  .setDuration(fadeOutDurationMs);
          mFadeOutAnimator.addUpdateListener(new AnimatorUpdateListener() {
              @Override
              public void onAnimationUpdate(ValueAnimator animation) {
                  setAlpha((Integer) animation.getAnimatedValue());
              }
          });
  
          reset();
      }
  
      public void reset() {
          setAlpha(0);
          setVisible(false);
      }
  
      public Drawable getInnerDrawable() {
          return mInner;
      }
  
      @Override
      protected void onBoundsChange(Rect bounds) {
          super.onBoundsChange(bounds);
  
          if (mInner == null) {
              return;
          }
  
          if (bounds.isEmpty()) {
              mInner.setBounds(0, 0, 0, 0);
          } else {
              final int l = bounds.left + (bounds.width() / 2) - (mInnerWidth / 2);
              final int t = bounds.top + (bounds.height() / 2) - (mInnerHeight / 2);
              mInner.setBounds(l, t, l + mInnerWidth, t + mInnerHeight);
          }
      }
  
      @Override
      public void draw(Canvas canvas) {
          if (!isVisible() && mPaint.getAlpha() == 0) {
              return;
          }
          final int alpha = mPaint.getAlpha();
          mPaint.setColor(mOpts.backgroundColor);
          mPaint.setAlpha(alpha);
          canvas.drawRect(getBounds(), mPaint);
          if (mInner != null) mInner.draw(canvas);
      }
  
      @Override
      public void setAlpha(int alpha) {
          final int old = mPaint.getAlpha();
          mPaint.setAlpha(alpha);
          setInnerAlpha(alpha);
          if (alpha != old) {
              invalidateSelf();
          }
      }
  
      @Override
      public void setColorFilter(ColorFilter cf) {
          mPaint.setColorFilter(cf);
          if (mInner != null) mInner.setColorFilter(cf);
      }
  
      @Override
      public int getOpacity() {
          return 0;
      }
  
      protected int getCurrentAlpha() {
          return mPaint.getAlpha();
      }
  
      public boolean setVisible(boolean visible) {
          return setVisible(visible, true /* dontcare */);
      }
  
      @Override
      public boolean setVisible(boolean visible, boolean restart) {
          if (mInner != null) mInner.setVisible(visible, restart);
          final boolean changed = super.setVisible(visible, restart);
          if (changed) {
              if (isVisible()) {
                  // pop in (no-op)
                  // the transition will still be smooth if the previous state's layer fades out
                  mFadeOutAnimator.cancel();
                  setAlpha(255);
              } else {
                  // fade out
                  if (mPaint.getAlpha() == 255) {
                      mFadeOutAnimator.start();
                  }
              }
          }
          return changed;
      }
  
      @Override
      protected boolean onLevelChange(int level) {
          if (mInner != null)
              return mInner.setLevel(level);
          else {
              return super.onLevelChange(level);
          }
      }
  
      /**
       * Changes the alpha on just the inner wrapped drawable.
       */
      public void setInnerAlpha(int alpha) {
          if (mInner != null) mInner.setAlpha(alpha);
      }
  
      @Override
      public void invalidateDrawable(Drawable who) {
          invalidateSelf();
      }
  
      @Override
      public void scheduleDrawable(Drawable who, Runnable what, long when) {
          scheduleSelf(what, when);
      }
  
      @Override
      public void unscheduleDrawable(Drawable who, Runnable what) {
          unscheduleSelf(what);
      }
  }
  