1 /*
2  * Copyright (C) 2017 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 com.android.launcher3.graphics;
18 
19 import android.graphics.Canvas;
20 import android.graphics.ColorFilter;
21 import android.graphics.Matrix;
22 import android.graphics.Outline;
23 import android.graphics.Paint;
24 import android.graphics.Path;
25 import android.graphics.PixelFormat;
26 import android.graphics.Rect;
27 import android.graphics.drawable.Drawable;
28 
29 public class FastScrollThumbDrawable extends Drawable {
30 
31     private static final Matrix sMatrix = new Matrix();
32 
33     private final Path mPath = new Path();
34     private final Paint mPaint;
35     private final boolean mIsRtl;
36 
FastScrollThumbDrawable(Paint paint, boolean isRtl)37     public FastScrollThumbDrawable(Paint paint, boolean isRtl) {
38         mPaint = paint;
39         mIsRtl = isRtl;
40     }
41 
42     @Override
getOutline(Outline outline)43     public void getOutline(Outline outline) {
44         if (mPath.isConvex()) {
45             outline.setConvexPath(mPath);
46         }
47     }
48 
49     @Override
onBoundsChange(Rect bounds)50     protected void onBoundsChange(Rect bounds) {
51         mPath.reset();
52 
53         float r = bounds.height()  * 0.5f;
54         // The path represents a rotate tear-drop shape, with radius of one corner is 1/5th of the
55         // other 3 corners.
56         float diameter = 2 * r;
57         float r2 = r / 5;
58         mPath.addRoundRect(bounds.left, bounds.top, bounds.left + diameter, bounds.top + diameter,
59                 new float[] {r, r, r, r, r2, r2, r, r},
60                 Path.Direction.CCW);
61 
62         sMatrix.setRotate(-45, bounds.left + r, bounds.top + r);
63         if (mIsRtl) {
64             sMatrix.postTranslate(bounds.width(), 0);
65             sMatrix.postScale(-1, 1, bounds.width(), 0);
66         }
67         mPath.transform(sMatrix);
68     }
69 
70     @Override
draw(Canvas canvas)71     public void draw(Canvas canvas) {
72         canvas.drawPath(mPath, mPaint);
73     }
74 
75     @Override
setAlpha(int i)76     public void setAlpha(int i) {
77         // Not supported
78     }
79 
80     @Override
setColorFilter(ColorFilter colorFilter)81     public void setColorFilter(ColorFilter colorFilter) {
82         // Not supported
83     }
84 
85     @Override
getOpacity()86     public int getOpacity() {
87         return PixelFormat.TRANSLUCENT;
88     }
89 }
90