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      1 /*
      2  * Copyright (C) 2016 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.example.android.apis.view;
     18 
     19 import android.content.Context;
     20 import android.graphics.Bitmap;
     21 import android.graphics.Canvas;
     22 import android.graphics.Paint;
     23 import android.util.AttributeSet;
     24 import android.util.Log;
     25 import android.view.MotionEvent;
     26 import android.view.PointerIcon;
     27 import android.widget.Button;
     28 
     29 public class LivePointerIconButton extends Button {
     30     public LivePointerIconButton(Context context) {
     31         this(context, null);
     32     }
     33 
     34     public LivePointerIconButton(Context context, AttributeSet attrs) {
     35         super(context, attrs);
     36     }
     37 
     38     public LivePointerIconButton(Context context, AttributeSet attrs, int defStyleAttr) {
     39         super(context, attrs, defStyleAttr);
     40     }
     41 
     42     public LivePointerIconButton(Context context, AttributeSet attrs,
     43                                   int defStyleAttr, int defStyleRes) {
     44         super(context, attrs, defStyleAttr, defStyleRes);
     45     }
     46 
     47     @Override
     48     public PointerIcon onResolvePointerIcon(MotionEvent event, int pointerIndex) {
     49         int cursorSize = getHeight();
     50 
     51         Bitmap bitmap = Bitmap.createBitmap(cursorSize, cursorSize, Bitmap.Config.ARGB_8888);
     52         Canvas canvas = new Canvas(bitmap);
     53 
     54         Paint paint = new Paint();
     55         paint.setARGB(255, 255, 255, 255);
     56         paint.setStyle(Paint.Style.STROKE);
     57         final int strokeWidth = 4;
     58         paint.setStrokeWidth(strokeWidth);
     59 
     60         // Draw a large circle filling the bitmap.
     61         final int outerCenterX = cursorSize / 2;
     62         final int outerCenterY = cursorSize / 2;
     63         final int outerRadius = cursorSize / 2 - strokeWidth;
     64         canvas.drawCircle(outerCenterX, outerCenterY, outerRadius, paint);
     65 
     66         // Compute relative offset of the mouse pointer from the view center.
     67         // It should be between -0.5 and 0.5.
     68         final float relativeX = (event.getX(pointerIndex) / getWidth()) - 0.5f;
     69         final float relativeY = (event.getY(pointerIndex) / getHeight()) - 0.5f;
     70 
     71         // Draw a smaller circle inside the large circle, offset towards the center of the view.
     72         final int innerCenterX = (int) (cursorSize * (1 - relativeX) / 2);
     73         final int innerCenterY = (int) (cursorSize * (1 - relativeY) / 2);
     74         final int innerRadius = cursorSize / 6;
     75         if (event.getAction() == MotionEvent.ACTION_MOVE) {
     76             // Fill the inner circle if the mouse button is down.
     77             paint.setStyle(Paint.Style.FILL);
     78         }
     79         canvas.drawCircle(innerCenterX, innerCenterY, innerRadius, paint);
     80 
     81         final int hotSpotX = bitmap.getWidth() / 2;
     82         final int hotSpotY = bitmap.getHeight() / 2;
     83         return PointerIcon.create(bitmap, hotSpotX, hotSpotY);
     84     }
     85 }
     86