org.eclipse.swt.snippets.Snippet214.java Source code

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Here is the source code for org.eclipse.swt.snippets.Snippet214.java

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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;

/*
 * Control example snippet: set a background image (a dynamic gradient)
 *
 * For a list of all SWT example snippets see
 * http://www.eclipse.org/swt/snippets/
 *
 * @since 3.2
 */
import org.eclipse.swt.*;
import org.eclipse.swt.graphics.*;
import org.eclipse.swt.layout.*;
import org.eclipse.swt.widgets.*;

public class Snippet214 {
    static Image oldImage;

    public static void main(String[] args) {
        final Display display = new Display();
        final Shell shell = new Shell(display);
        shell.setText("Snippet 214");
        shell.setBackgroundMode(SWT.INHERIT_DEFAULT);
        FillLayout layout1 = new FillLayout(SWT.VERTICAL);
        layout1.marginWidth = layout1.marginHeight = 10;
        shell.setLayout(layout1);
        Group group = new Group(shell, SWT.NONE);
        group.setText("Group ");
        RowLayout layout2 = new RowLayout(SWT.VERTICAL);
        layout2.marginWidth = layout2.marginHeight = layout2.spacing = 10;
        group.setLayout(layout2);
        for (int i = 0; i < 8; i++) {
            Button button = new Button(group, SWT.RADIO);
            button.setText("Button " + i);
        }
        shell.addListener(SWT.Resize, event -> {
            Rectangle rect = shell.getClientArea();
            Image newImage = new Image(display, Math.max(1, rect.width), 1);
            GC gc = new GC(newImage);
            gc.setForeground(display.getSystemColor(SWT.COLOR_WHITE));
            gc.setBackground(display.getSystemColor(SWT.COLOR_BLUE));
            gc.fillGradientRectangle(rect.x, rect.y, rect.width, 1, false);
            gc.dispose();
            shell.setBackgroundImage(newImage);
            if (oldImage != null)
                oldImage.dispose();
            oldImage = newImage;
        });
        shell.pack();
        shell.open();
        while (!shell.isDisposed()) {
            if (!display.readAndDispatch())
                display.sleep();
        }
        if (oldImage != null)
            oldImage.dispose();
        display.dispose();
    }
}