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 
RippleComponent(RippleDrawable owner, Rect bounds)47     public RippleComponent(RippleDrawable owner, Rect bounds) {
48         mOwner = owner;
49         mBounds = bounds;
50     }
51 
onBoundsChange()52     public void onBoundsChange() {
53         if (!mHasMaxRadius) {
54             mTargetRadius = getTargetRadius(mBounds);
55             onTargetRadiusChanged(mTargetRadius);
56         }
57     }
58 
setup(float maxRadius, int densityDpi)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 
getTargetRadius(Rect bounds)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      */
getBounds(Rect bounds)85     public void getBounds(Rect bounds) {
86         final int r = (int) Math.ceil(mTargetRadius);
87         bounds.set(-r, -r, r, r);
88     }
89 
invalidateSelf()90     protected final void invalidateSelf() {
91         mOwner.invalidateSelf(false);
92     }
93 
onHotspotBoundsChanged()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      */
onTargetRadiusChanged(float targetRadius)106     protected void onTargetRadiusChanged(float targetRadius) {
107         // Stub.
108     }
109 }
110