Regions
/*
* Copyright (C) 2007 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 app.test;
import android.app.Activity;
import android.content.Context;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.graphics.Picture;
import android.graphics.Rect;
import android.graphics.Region;
import android.graphics.RegionIterator;
import android.graphics.drawable.Drawable;
import android.os.Bundle;
import android.util.AttributeSet;
import android.view.View;
import android.view.ViewGroup;
import android.view.ViewParent;
public class Test 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();
}
}
}
class GraphicsActivity extends Activity {
// set to true to test Picture
private static final boolean TEST_PICTURE = false;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
}
@Override
public void setContentView(View view) {
if (TEST_PICTURE) {
ViewGroup vg = new PictureLayout(this);
vg.addView(view);
view = vg;
}
super.setContentView(view);
}
}
class PictureLayout extends ViewGroup {
private final Picture mPicture = new Picture();
public PictureLayout(Context context) {
super(context);
}
public PictureLayout(Context context, AttributeSet attrs) {
super(context, attrs);
}
@Override
public void addView(View child) {
if (getChildCount() > 1) {
throw new IllegalStateException(
"PictureLayout can host only one direct child");
}
super.addView(child);
}
@Override
public void addView(View child, int index) {
if (getChildCount() > 1) {
throw new IllegalStateException(
"PictureLayout can host only one direct child");
}
super.addView(child, index);
}
@Override
public void addView(View child, LayoutParams params) {
if (getChildCount() > 1) {
throw new IllegalStateException(
"PictureLayout can host only one direct child");
}
super.addView(child, params);
}
@Override
public void addView(View child, int index, LayoutParams params) {
if (getChildCount() > 1) {
throw new IllegalStateException(
"PictureLayout can host only one direct child");
}
super.addView(child, index, params);
}
@Override
protected LayoutParams generateDefaultLayoutParams() {
return new LayoutParams(LayoutParams.MATCH_PARENT,
LayoutParams.MATCH_PARENT);
}
@Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
final int count = getChildCount();
int maxHeight = 0;
int maxWidth = 0;
for (int i = 0; i < count; i++) {
final View child = getChildAt(i);
if (child.getVisibility() != GONE) {
measureChild(child, widthMeasureSpec, heightMeasureSpec);
}
}
maxWidth += getPaddingLeft() + getPaddingRight();
maxHeight += getPaddingTop() + getPaddingBottom();
Drawable drawable = getBackground();
if (drawable != null) {
maxHeight = Math.max(maxHeight, drawable.getMinimumHeight());
maxWidth = Math.max(maxWidth, drawable.getMinimumWidth());
}
setMeasuredDimension(resolveSize(maxWidth, widthMeasureSpec),
resolveSize(maxHeight, heightMeasureSpec));
}
private void drawPict(Canvas canvas, int x, int y, int w, int h, float sx,
float sy) {
canvas.save();
canvas.translate(x, y);
canvas.clipRect(0, 0, w, h);
canvas.scale(0.5f, 0.5f);
canvas.scale(sx, sy, w, h);
canvas.drawPicture(mPicture);
canvas.restore();
}
@Override
protected void dispatchDraw(Canvas canvas) {
super.dispatchDraw(mPicture.beginRecording(getWidth(), getHeight()));
mPicture.endRecording();
int x = getWidth() / 2;
int y = getHeight() / 2;
if (false) {
canvas.drawPicture(mPicture);
} else {
drawPict(canvas, 0, 0, x, y, 1, 1);
drawPict(canvas, x, 0, x, y, -1, 1);
drawPict(canvas, 0, y, x, y, 1, -1);
drawPict(canvas, x, y, x, y, -1, -1);
}
}
@Override
public ViewParent invalidateChildInParent(int[] location, Rect dirty) {
location[0] = getLeft();
location[1] = getTop();
dirty.set(0, 0, getWidth(), getHeight());
return getParent();
}
@Override
protected void onLayout(boolean changed, int l, int t, int r, int b) {
final int count = super.getChildCount();
for (int i = 0; i < count; i++) {
final View child = getChildAt(i);
if (child.getVisibility() != GONE) {
final int childLeft = getPaddingLeft();
final int childTop = getPaddingTop();
child.layout(childLeft, childTop,
childLeft + child.getMeasuredWidth(),
childTop + child.getMeasuredHeight());
}
}
}
}
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