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.colorpicker;
  
  import android.graphics.Color;
  import android.graphics.PorterDuff;
  import android.graphics.drawable.Drawable;
  import android.graphics.drawable.LayerDrawable;
  
  /**
   * A drawable which sets its color filter to a color specified by the user, and changes to a
   * slightly darker color when pressed or focused.
   */
  public class ColorStateDrawable extends LayerDrawable {
  
      private static final float PRESSED_STATE_MULTIPLIER = 0.70f;
  
      private int mColor;
  
      public ColorStateDrawable(Drawable[] layers, int color) {
          super(layers);
          mColor = color;
      }
  
      @Override
      protected boolean onStateChange(int[] states) {
          boolean pressedOrFocused = false;
          for (int state : states) {
              if (state == android.R.attr.state_pressed || state == android.R.attr.state_focused) {
                  pressedOrFocused = true;
                  break;
              }
          }
  
          if (pressedOrFocused) {
              super.setColorFilter(getPressedColor(mColor), PorterDuff.Mode.SRC_ATOP);
          } else {
              super.setColorFilter(mColor, PorterDuff.Mode.SRC_ATOP);
          }
  
          return super.onStateChange(states);
      }
  
      /**
       * Given a particular color, adjusts its value by a multiplier.
       */
      private static int getPressedColor(int color) {
          float[] hsv = new float[3];
          Color.colorToHSV(color, hsv);
          hsv[2] = hsv[2] * PRESSED_STATE_MULTIPLIER;
          return Color.HSVToColor(hsv);
      }
  
      @Override
      public boolean isStateful() {
          return true;
      }
  }
  