1 /* 2 * Copyright (C) 2008 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.graphics; 18 19 import android.app.Activity; 20 import android.content.Context; 21 import android.graphics.*; 22 import android.os.Bundle; 23 import android.view.View; 24 25 public class Clipping extends GraphicsActivity { 26 27 @Override onCreate(Bundle savedInstanceState)28 protected void onCreate(Bundle savedInstanceState) { 29 super.onCreate(savedInstanceState); 30 setContentView(new SampleView(this)); 31 } 32 33 private static class SampleView extends View { 34 private Paint mPaint; 35 private Path mPath; 36 SampleView(Context context)37 public SampleView(Context context) { 38 super(context); 39 setFocusable(true); 40 41 mPaint = new Paint(); 42 mPaint.setAntiAlias(true); 43 mPaint.setStrokeWidth(6); 44 mPaint.setTextSize(16); 45 mPaint.setTextAlign(Paint.Align.RIGHT); 46 47 mPath = new Path(); 48 } 49 drawScene(Canvas canvas)50 private void drawScene(Canvas canvas) { 51 canvas.clipRect(0, 0, 100, 100); 52 53 canvas.drawColor(Color.WHITE); 54 55 mPaint.setColor(Color.RED); 56 canvas.drawLine(0, 0, 100, 100, mPaint); 57 58 mPaint.setColor(Color.GREEN); 59 canvas.drawCircle(30, 70, 30, mPaint); 60 61 mPaint.setColor(Color.BLUE); 62 canvas.drawText("Clipping", 100, 30, mPaint); 63 } 64 onDraw(Canvas canvas)65 @Override protected void onDraw(Canvas canvas) { 66 canvas.drawColor(Color.GRAY); 67 68 canvas.save(); 69 canvas.translate(10, 10); 70 drawScene(canvas); 71 canvas.restore(); 72 73 canvas.save(); 74 canvas.translate(160, 10); 75 canvas.clipRect(10, 10, 90, 90); 76 canvas.clipRect(30, 30, 70, 70, Region.Op.DIFFERENCE); 77 drawScene(canvas); 78 canvas.restore(); 79 80 canvas.save(); 81 canvas.translate(10, 160); 82 mPath.reset(); 83 canvas.clipPath(mPath); // makes the clip empty 84 mPath.addCircle(50, 50, 50, Path.Direction.CCW); 85 canvas.clipPath(mPath, Region.Op.REPLACE); 86 drawScene(canvas); 87 canvas.restore(); 88 89 canvas.save(); 90 canvas.translate(160, 160); 91 canvas.clipRect(0, 0, 60, 60); 92 canvas.clipRect(40, 40, 100, 100, Region.Op.UNION); 93 drawScene(canvas); 94 canvas.restore(); 95 96 canvas.save(); 97 canvas.translate(10, 310); 98 canvas.clipRect(0, 0, 60, 60); 99 canvas.clipRect(40, 40, 100, 100, Region.Op.XOR); 100 drawScene(canvas); 101 canvas.restore(); 102 103 canvas.save(); 104 canvas.translate(160, 310); 105 canvas.clipRect(0, 0, 60, 60); 106 canvas.clipRect(40, 40, 100, 100, Region.Op.REVERSE_DIFFERENCE); 107 drawScene(canvas); 108 canvas.restore(); 109 } 110 } 111 } 112 113