content: /*
   * Copyright (C) 2015 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.graphics.Rect;
  import android.util.DisplayMetrics;
  
  /**
   * Abstract class that handles size & positioning common to the ripple & focus states.
   */
  abstract class RippleComponent {
      protected final RippleDrawable mOwner;
  
      /** Bounds used for computing max radius. May be modified by the owner. */
      protected final Rect mBounds;
  
      /** Whether we have an explicit maximum radius. */
      private boolean mHasMaxRadius;
  
      /** How big this ripple should be when fully entered. */
      protected float mTargetRadius;
  
      /** Screen density used to adjust pixel-based constants. */
      protected float mDensityScale;
  
      public RippleComponent(RippleDrawable owner, Rect bounds) {
          mOwner = owner;
          mBounds = bounds;
      }
  
      public void onBoundsChange() {
          if (!mHasMaxRadius) {
              mTargetRadius = getTargetRadius(mBounds);
              onTargetRadiusChanged(mTargetRadius);
          }
      }
  
      public final void setup(float maxRadius, int densityDpi) {
          if (maxRadius >= 0) {
              mHasMaxRadius = true;
              mTargetRadius = maxRadius;
          } else {
              mTargetRadius = getTargetRadius(mBounds);
          }
  
          mDensityScale = densityDpi * DisplayMetrics.DENSITY_DEFAULT_SCALE;
  
          onTargetRadiusChanged(mTargetRadius);
      }
  
      private static float getTargetRadius(Rect bounds) {
          final float halfWidth = bounds.width() / 2.0f;
          final float halfHeight = bounds.height() / 2.0f;
          return (float) Math.sqrt(halfWidth * halfWidth + halfHeight * halfHeight);
      }
  
      /**
       * Populates {@code bounds} with the maximum drawing bounds of the ripple
       * relative to its center. The resulting bounds should be translated into
       * parent drawable coordinates before use.
       *
       * @param bounds the rect to populate with drawing bounds
       */
      public void getBounds(Rect bounds) {
          final int r = (int) Math.ceil(mTargetRadius);
          bounds.set(-r, -r, r, r);
      }
  
      protected final void invalidateSelf() {
          mOwner.invalidateSelf(false);
      }
  
      protected final void onHotspotBoundsChanged() {
          if (!mHasMaxRadius) {
              mTargetRadius = getTargetRadius(mBounds);
              onTargetRadiusChanged(mTargetRadius);
          }
      }
  
      /**
       * Called when the target radius changes.
       *
       * @param targetRadius the new target radius
       */
      protected void onTargetRadiusChanged(float targetRadius) {
          // Stub.
      }
  }
  