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/*
* Copyright (C) 2008 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.example.android.apis.graphics;
import android.content.Context;
import android.graphics.*;
import android.os.Bundle;
import android.view.View;
public class Regions extends GraphicsActivity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(new SampleView(this));
}
private static class SampleView extends View {
private final Paint mPaint = new Paint();
private final Rect mRect1 = new Rect();
private final Rect mRect2 = new Rect();
public SampleView(Context context) {
super(context);
setFocusable(true);
mPaint.setAntiAlias(true);
mPaint.setTextSize(16);
mPaint.setTextAlign(Paint.Align.CENTER);
mRect1.set(10, 10, 100, 80);
mRect2.set(50, 50, 130, 110);
}
private void drawOriginalRects(Canvas canvas, int alpha) {
mPaint.setStyle(Paint.Style.STROKE);
mPaint.setColor(Color.RED);
mPaint.setAlpha(alpha);
drawCentered(canvas, mRect1, mPaint);
mPaint.setColor(Color.BLUE);
mPaint.setAlpha(alpha);
drawCentered(canvas, mRect2, mPaint);
// restore style
mPaint.setStyle(Paint.Style.FILL);
}
private void drawRgn(Canvas canvas, int color, String str, Region.Op op) {
if (str != null) {
mPaint.setColor(Color.BLACK);
canvas.drawText(str, 80, 24, mPaint);
}
Region rgn = new Region();
rgn.set(mRect1);
rgn.op(mRect2, op);
mPaint.setColor(color);
RegionIterator iter = new RegionIterator(rgn);
Rect r = new Rect();
canvas.translate(0, 30);
mPaint.setColor(color);
while (iter.next(r)) {
canvas.drawRect(r, mPaint);
}
drawOriginalRects(canvas, 0x80);
}
private static void drawCentered(Canvas c, Rect r, Paint p) {
float inset = p.getStrokeWidth() * 0.5f;
if (inset == 0) { // catch hairlines
inset = 0.5f;
}
c.drawRect(r.left + inset, r.top + inset,
r.right - inset, r.bottom - inset, p);
}
@Override
protected void onDraw(Canvas canvas) {
canvas.drawColor(Color.GRAY);
canvas.save();
canvas.translate(80, 5);
drawOriginalRects(canvas, 0xFF);
canvas.restore();
mPaint.setStyle(Paint.Style.FILL);
canvas.save();
canvas.translate(0, 140);
drawRgn(canvas, Color.RED, "Union", Region.Op.UNION);
canvas.restore();
canvas.save();
canvas.translate(0, 280);
drawRgn(canvas, Color.BLUE, "Xor", Region.Op.XOR);
canvas.restore();
canvas.save();
canvas.translate(160, 140);
drawRgn(canvas, Color.GREEN, "Difference", Region.Op.DIFFERENCE);
canvas.restore();
canvas.save();
canvas.translate(160, 280);
drawRgn(canvas, Color.WHITE, "Intersect", Region.Op.INTERSECT);
canvas.restore();
}
}
}
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