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      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 
     37     public FastScrollThumbDrawable(Paint paint, boolean isRtl) {
     38         mPaint = paint;
     39         mIsRtl = isRtl;
     40     }
     41 
     42     @Override
     43     public void getOutline(Outline outline) {
     44         if (mPath.isConvex()) {
     45             outline.setConvexPath(mPath);
     46         }
     47     }
     48 
     49     @Override
     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
     71     public void draw(Canvas canvas) {
     72         canvas.drawPath(mPath, mPaint);
     73     }
     74 
     75     @Override
     76     public void setAlpha(int i) {
     77         // Not supported
     78     }
     79 
     80     @Override
     81     public void setColorFilter(ColorFilter colorFilter) {
     82         // Not supported
     83     }
     84 
     85     @Override
     86     public int getOpacity() {
     87         return PixelFormat.TRANSLUCENT;
     88     }
     89 }
     90