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 Regions 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 final Paint mPaint = new Paint(); 35 private final Rect mRect1 = new Rect(); 36 private final Rect mRect2 = new Rect(); 37 SampleView(Context context)38 public SampleView(Context context) { 39 super(context); 40 setFocusable(true); 41 42 mPaint.setAntiAlias(true); 43 mPaint.setTextSize(16); 44 mPaint.setTextAlign(Paint.Align.CENTER); 45 46 mRect1.set(10, 10, 100, 80); 47 mRect2.set(50, 50, 130, 110); 48 } 49 drawOriginalRects(Canvas canvas, int alpha)50 private void drawOriginalRects(Canvas canvas, int alpha) { 51 mPaint.setStyle(Paint.Style.STROKE); 52 mPaint.setColor(Color.RED); 53 mPaint.setAlpha(alpha); 54 drawCentered(canvas, mRect1, mPaint); 55 mPaint.setColor(Color.BLUE); 56 mPaint.setAlpha(alpha); 57 drawCentered(canvas, mRect2, mPaint); 58 59 // restore style 60 mPaint.setStyle(Paint.Style.FILL); 61 } 62 drawRgn(Canvas canvas, int color, String str, Region.Op op)63 private void drawRgn(Canvas canvas, int color, String str, Region.Op op) { 64 if (str != null) { 65 mPaint.setColor(Color.BLACK); 66 canvas.drawText(str, 80, 24, mPaint); 67 } 68 69 Region rgn = new Region(); 70 rgn.set(mRect1); 71 rgn.op(mRect2, op); 72 73 mPaint.setColor(color); 74 RegionIterator iter = new RegionIterator(rgn); 75 Rect r = new Rect(); 76 77 canvas.translate(0, 30); 78 mPaint.setColor(color); 79 while (iter.next(r)) { 80 canvas.drawRect(r, mPaint); 81 } 82 drawOriginalRects(canvas, 0x80); 83 } 84 drawCentered(Canvas c, Rect r, Paint p)85 private static void drawCentered(Canvas c, Rect r, Paint p) { 86 float inset = p.getStrokeWidth() * 0.5f; 87 if (inset == 0) { // catch hairlines 88 inset = 0.5f; 89 } 90 c.drawRect(r.left + inset, r.top + inset, 91 r.right - inset, r.bottom - inset, p); 92 } 93 onDraw(Canvas canvas)94 @Override protected void onDraw(Canvas canvas) { 95 canvas.drawColor(Color.GRAY); 96 97 canvas.save(); 98 canvas.translate(80, 5); 99 drawOriginalRects(canvas, 0xFF); 100 canvas.restore(); 101 102 mPaint.setStyle(Paint.Style.FILL); 103 104 canvas.save(); 105 canvas.translate(0, 140); 106 drawRgn(canvas, Color.RED, "Union", Region.Op.UNION); 107 canvas.restore(); 108 109 canvas.save(); 110 canvas.translate(0, 280); 111 drawRgn(canvas, Color.BLUE, "Xor", Region.Op.XOR); 112 canvas.restore(); 113 114 canvas.save(); 115 canvas.translate(160, 140); 116 drawRgn(canvas, Color.GREEN, "Difference", Region.Op.DIFFERENCE); 117 canvas.restore(); 118 119 canvas.save(); 120 canvas.translate(160, 280); 121 drawRgn(canvas, Color.WHITE, "Intersect", Region.Op.INTERSECT); 122 canvas.restore(); 123 } 124 } 125 } 126 127