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/*******************************************************************************
* Copyright (c) 2000, 2016 IBM Corporation and others.
*
* This program and the accompanying materials
* are made available under the terms of the Eclipse Public License 2.0
* which accompanies this distribution, and is available at
* https://www.eclipse.org/legal/epl-2.0/
*
* SPDX-License-Identifier: EPL-2.0
*
* Contributors:
* IBM Corporation - initial API and implementation
*******************************************************************************/
package org.eclipse.swt.snippets;
import org.eclipse.swt.*;
import org.eclipse.swt.graphics.*;
import org.eclipse.swt.layout.*;
import org.eclipse.swt.widgets.*;
/*
* Region on a control: create a non-rectangular button
*
* For a list of all SWT example snippets see
* http://www.eclipse.org/swt/snippets/
*
* @since 3.4
*/
public class Snippet294 {
static int[] circle(int r, int offsetX, int offsetY) {
int[] polygon = new int[8 * r + 4];
// x^2 + y^2 = r^2
for (int i = 0; i < 2 * r + 1; i++) {
int x = i - r;
int y = (int)Math.sqrt(r*r - x*x);
polygon[2*i] = offsetX + x;
polygon[2*i+1] = offsetY + y;
polygon[8*r - 2*i - 2] = offsetX + x;
polygon[8*r - 2*i - 1] = offsetY - y;
}
return polygon;
}
public static void main(String[] args) {
final Display display = new Display();
final Shell shell = new Shell(display);
shell.setText("Regions on a Control");
shell.setLayout(new FillLayout());
shell.setBackground(display.getSystemColor(SWT.COLOR_DARK_RED));
Button b2 = new Button(shell, SWT.PUSH);
b2.setText("Button with Regions");
// define a region that looks like a circle with two holes in ot
Region region = new Region();
region.add(circle(67, 87, 77));
region.subtract(circle(20, 87, 47));
region.subtract(circle(20, 87, 113));
// define the shape of the button using setRegion
b2.setRegion(region);
b2.setLocation(100,50);
b2.addListener(SWT.Selection, e -> shell.close());
shell.setSize(200,200);
shell.open();
while (!shell.isDisposed()) {
if (!display.readAndDispatch())
display.sleep();
}
region.dispose();
display.dispose();
}
}
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