ScrollWidgetViewFocusIn.java Source code

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Here is the source code for ScrollWidgetViewFocusIn.java

Source

/*******************************************************************************
 * Copyright (c) 2000, 2005 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
 ******************************************************************************/
// package org.eclipse.swt.snippets;
import org.eclipse.swt.SWT;
import org.eclipse.swt.custom.ScrolledComposite;
import org.eclipse.swt.graphics.Point;
import org.eclipse.swt.graphics.Rectangle;
import org.eclipse.swt.layout.GridData;
import org.eclipse.swt.layout.GridLayout;
import org.eclipse.swt.widgets.Button;
import org.eclipse.swt.widgets.Composite;
import org.eclipse.swt.widgets.Control;
import org.eclipse.swt.widgets.Display;
import org.eclipse.swt.widgets.Event;
import org.eclipse.swt.widgets.Listener;
import org.eclipse.swt.widgets.Shell;

/*
 * Scroll a widget into view on focus in
 * 
 * For a list of all SWT example snippets see
 * http://www.eclipse.org/swt/snippets/
 * 
 * @since 3.0
 */

public class ScrollWidgetViewFocusIn {

    public static void main(String[] args) {
        Display display = new Display();
        Shell shell = new Shell(display);
        shell.setLayout(new GridLayout());
        Button b1 = new Button(shell, SWT.PUSH);
        b1.setText("top");
        b1.setLayoutData(new GridData(SWT.FILL, SWT.CENTER, false, false, 1, 1));
        final ScrolledComposite sc = new ScrolledComposite(shell, SWT.BORDER | SWT.H_SCROLL | SWT.V_SCROLL);
        sc.setLayoutData(new GridData(SWT.FILL, SWT.FILL, true, true, 1, 1));
        Composite c = new Composite(sc, SWT.NONE);
        c.setLayout(new GridLayout(10, true));
        for (int i = 0; i < 300; i++) {
            Button b = new Button(c, SWT.PUSH);
            b.setText("Button " + i);
        }
        Button b2 = new Button(shell, SWT.PUSH);
        b2.setText("bottom");
        b2.setLayoutData(new GridData(SWT.FILL, SWT.CENTER, false, false, 1, 1));

        sc.setContent(c);
        sc.setExpandHorizontal(true);
        sc.setExpandVertical(true);
        sc.setMinSize(c.computeSize(SWT.DEFAULT, SWT.DEFAULT));

        Listener listener = new Listener() {
            public void handleEvent(Event e) {
                Control child = (Control) e.widget;
                Rectangle bounds = child.getBounds();
                Rectangle area = sc.getClientArea();
                Point origin = sc.getOrigin();
                if (origin.x > bounds.x)
                    origin.x = Math.max(0, bounds.x);
                if (origin.y > bounds.y)
                    origin.y = Math.max(0, bounds.y);
                if (origin.x + area.width < bounds.x + bounds.width)
                    origin.x = Math.max(0, bounds.x + bounds.width - area.width);
                if (origin.y + area.height < bounds.y + bounds.height)
                    origin.y = Math.max(0, bounds.y + bounds.height - area.height);
                sc.setOrigin(origin);
            }
        };
        Control[] controls = c.getChildren();
        for (int i = 0; i < controls.length; i++) {
            controls[i].addListener(SWT.Activate, listener);
        }
        shell.setSize(300, 500);
        shell.open();
        while (!shell.isDisposed()) {
            if (!display.readAndDispatch())
                display.sleep();
        }
        display.dispose();
    }
}