/*******************************************************************************
 * Copyright (c) 2000, 2008 IBM Corporation and others.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 *
 * Contributors:
 *     IBM Corporation - initial API and implementation
 * D Port:
 *     Thomas Demmer <t_demmer AT web DOT de>
 *******************************************************************************/
module org.eclipse.swt.snippets.Snippet294;

/*
 * 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
 */
import org.eclipse.swt.SWT;
import org.eclipse.swt.graphics.Image;
import org.eclipse.swt.graphics.Region;
import org.eclipse.swt.layout.FillLayout;
import org.eclipse.swt.widgets.Button;
import org.eclipse.swt.widgets.Display;
import org.eclipse.swt.widgets.Event;
import org.eclipse.swt.widgets.Listener;
import org.eclipse.swt.widgets.Shell;

import java.lang.all;
version(Tango){
    import tango.util.Convert;
} else { // Phobos
    import std.conv;
}

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 = cast(int)Math.sqrt(cast(real)(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;
}

void main() {
    Display display = new Display();
    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, new class Listener {
        public void handleEvent(Event e) {
            shell.close();
        }
    });

    shell.setSize(200,200);
    shell.open();

    while (!shell.isDisposed()) {
        if (!display.readAndDispatch())
            display.sleep();
    }
    region.dispose();
    display.dispose();
}