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      1 /*
      2  * Copyright (C) 2015 The Android Open Source Project
      3  *
      4  * Licensed under the Apache License, Version 2.0 (the "License");
      5  * you may not use this file except in compliance with the License.
      6  * You may obtain a copy of the License at
      7  *
      8  *      http://www.apache.org/licenses/LICENSE-2.0
      9  *
     10  * Unless required by applicable law or agreed to in writing, software
     11  * distributed under the License is distributed on an "AS IS" BASIS,
     12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
     13  * See the License for the specific language governing permissions and
     14  * limitations under the License.
     15  */
     16 
     17 package android.graphics.drawable;
     18 
     19 import android.animation.Animator;
     20 import android.graphics.Canvas;
     21 import android.graphics.Paint;
     22 import android.graphics.Rect;
     23 import android.util.DisplayMetrics;
     24 import android.view.DisplayListCanvas;
     25 import android.view.RenderNodeAnimator;
     26 
     27 import java.util.ArrayList;
     28 
     29 /**
     30  * Abstract class that handles size & positioning common to the ripple & focus states.
     31  */
     32 abstract class RippleComponent {
     33     protected final RippleDrawable mOwner;
     34 
     35     /** Bounds used for computing max radius. May be modified by the owner. */
     36     protected final Rect mBounds;
     37 
     38     /** Whether we have an explicit maximum radius. */
     39     private boolean mHasMaxRadius;
     40 
     41     /** How big this ripple should be when fully entered. */
     42     protected float mTargetRadius;
     43 
     44     /** Screen density used to adjust pixel-based constants. */
     45     protected float mDensityScale;
     46 
     47     public RippleComponent(RippleDrawable owner, Rect bounds) {
     48         mOwner = owner;
     49         mBounds = bounds;
     50     }
     51 
     52     public void onBoundsChange() {
     53         if (!mHasMaxRadius) {
     54             mTargetRadius = getTargetRadius(mBounds);
     55             onTargetRadiusChanged(mTargetRadius);
     56         }
     57     }
     58 
     59     public final void setup(float maxRadius, int densityDpi) {
     60         if (maxRadius >= 0) {
     61             mHasMaxRadius = true;
     62             mTargetRadius = maxRadius;
     63         } else {
     64             mTargetRadius = getTargetRadius(mBounds);
     65         }
     66 
     67         mDensityScale = densityDpi * DisplayMetrics.DENSITY_DEFAULT_SCALE;
     68 
     69         onTargetRadiusChanged(mTargetRadius);
     70     }
     71 
     72     private static float getTargetRadius(Rect bounds) {
     73         final float halfWidth = bounds.width() / 2.0f;
     74         final float halfHeight = bounds.height() / 2.0f;
     75         return (float) Math.sqrt(halfWidth * halfWidth + halfHeight * halfHeight);
     76     }
     77 
     78     /**
     79      * Populates {@code bounds} with the maximum drawing bounds of the ripple
     80      * relative to its center. The resulting bounds should be translated into
     81      * parent drawable coordinates before use.
     82      *
     83      * @param bounds the rect to populate with drawing bounds
     84      */
     85     public void getBounds(Rect bounds) {
     86         final int r = (int) Math.ceil(mTargetRadius);
     87         bounds.set(-r, -r, r, r);
     88     }
     89 
     90     protected final void invalidateSelf() {
     91         mOwner.invalidateSelf(false);
     92     }
     93 
     94     protected final void onHotspotBoundsChanged() {
     95         if (!mHasMaxRadius) {
     96             mTargetRadius = getTargetRadius(mBounds);
     97             onTargetRadiusChanged(mTargetRadius);
     98         }
     99     }
    100 
    101     /**
    102      * Called when the target radius changes.
    103      *
    104      * @param targetRadius the new target radius
    105      */
    106     protected void onTargetRadiusChanged(float targetRadius) {
    107         // Stub.
    108     }
    109 }
    110