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 android.graphics.drawable;
  
  import android.animation.ObjectAnimator;
  import android.animation.TimeInterpolator;
  import android.graphics.Canvas;
  import android.graphics.Paint;
  import android.graphics.Rect;
  import android.util.FloatProperty;
  import android.view.animation.LinearInterpolator;
  
  /**
   * Draws a ripple background.
   */
  class RippleBackground extends RippleComponent {
  
      private static final TimeInterpolator LINEAR_INTERPOLATOR = new LinearInterpolator();
  
      private static final int OPACITY_DURATION = 80;
  
      private ObjectAnimator mAnimator;
  
      private float mOpacity = 0;
  
      /** Whether this ripple is bounded. */
      private boolean mIsBounded;
  
      private boolean mFocused = false;
      private boolean mHovered = false;
  
      public RippleBackground(RippleDrawable owner, Rect bounds, boolean isBounded) {
          super(owner, bounds);
  
          mIsBounded = isBounded;
      }
  
      public boolean isVisible() {
          return mOpacity > 0;
      }
  
      public void draw(Canvas c, Paint p) {
          final int origAlpha = p.getAlpha();
          final int alpha = Math.min((int) (origAlpha * mOpacity + 0.5f), 255);
          if (alpha > 0) {
              p.setAlpha(alpha);
              c.drawCircle(0, 0, mTargetRadius, p);
              p.setAlpha(origAlpha);
          }
      }
  
      public void setState(boolean focused, boolean hovered, boolean pressed) {
          if (!mFocused) {
              focused = focused && !pressed;
          }
          if (!mHovered) {
              hovered = hovered && !pressed;
          }
          if (mHovered != hovered || mFocused != focused) {
              mHovered = hovered;
              mFocused = focused;
              onStateChanged();
          }
      }
  
      private void onStateChanged() {
          // Hover             = .2 * alpha
          // Focus             = .6 * alpha
          // Focused + Hovered = .6 * alpha
          float newOpacity = mFocused ? .6f : mHovered ? .2f : 0f;
          if (mAnimator != null) {
              mAnimator.cancel();
              mAnimator = null;
          }
          mAnimator = ObjectAnimator.ofFloat(this, OPACITY, newOpacity);
          mAnimator.setDuration(OPACITY_DURATION);
          mAnimator.setInterpolator(LINEAR_INTERPOLATOR);
          mAnimator.start();
      }
  
      public void jumpToFinal() {
          if (mAnimator != null) {
              mAnimator.end();
              mAnimator = null;
          }
      }
  
      private static abstract class BackgroundProperty extends FloatProperty<RippleBackground> {
          public BackgroundProperty(String name) {
              super(name);
          }
      }
  
      private static final BackgroundProperty OPACITY = new BackgroundProperty("opacity") {
          @Override
          public void setValue(RippleBackground object, float value) {
              object.mOpacity = value;
              object.invalidateSelf();
          }
  
          @Override
          public Float get(RippleBackground object) {
              return object.mOpacity;
          }
      };
  }
  