content: /*
   * Copyright (C) 2019 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.graphics;
  
  import static com.android.launcher3.icons.GraphicsUtils.setColorAlphaBound;
  
  import android.graphics.Canvas;
  import android.util.Property;
  import android.view.View;
  
  import com.android.launcher3.Launcher;
  import com.android.launcher3.uioverrides.WallpaperColorInfo;
  
  /**
   * Contains general scrim properties such as wallpaper-extracted color that subclasses can use.
   */
  public class Scrim implements View.OnAttachStateChangeListener,
          WallpaperColorInfo.OnChangeListener {
  
      public static Property<Scrim, Float> SCRIM_PROGRESS =
              new Property<Scrim, Float>(Float.TYPE, "scrimProgress") {
                  @Override
                  public Float get(Scrim scrim) {
                      return scrim.mScrimProgress;
                  }
  
                  @Override
                  public void set(Scrim scrim, Float value) {
                      scrim.setScrimProgress(value);
                  }
              };
  
      protected final Launcher mLauncher;
      protected final WallpaperColorInfo mWallpaperColorInfo;
      protected final View mRoot;
  
      protected float mScrimProgress;
      protected int mScrimColor;
      protected int mScrimAlpha = 0;
  
      public Scrim(View view) {
          mRoot = view;
          mLauncher = Launcher.getLauncher(view.getContext());
          mWallpaperColorInfo = WallpaperColorInfo.getInstance(mLauncher);
  
          view.addOnAttachStateChangeListener(this);
      }
  
      public void draw(Canvas canvas) {
          canvas.drawColor(setColorAlphaBound(mScrimColor, mScrimAlpha));
      }
  
      private void setScrimProgress(float progress) {
          if (mScrimProgress != progress) {
              mScrimProgress = progress;
              mScrimAlpha = Math.round(255 * mScrimProgress);
              invalidate();
          }
      }
  
      @Override
      public void onViewAttachedToWindow(View view) {
          mWallpaperColorInfo.addOnChangeListener(this);
          onExtractedColorsChanged(mWallpaperColorInfo);
      }
  
      @Override
      public void onViewDetachedFromWindow(View view) {
          mWallpaperColorInfo.removeOnChangeListener(this);
      }
  
      @Override
      public void onExtractedColorsChanged(WallpaperColorInfo wallpaperColorInfo) {
          mScrimColor = wallpaperColorInfo.getMainColor();
          if (mScrimAlpha > 0) {
              invalidate();
          }
      }
  
      public void invalidate() {
          mRoot.invalidate();
      }
  }
  