org.eclipse.swt.snippets.Snippet358.java Source code

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Here is the source code for org.eclipse.swt.snippets.Snippet358.java

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/*******************************************************************************
 * Copyright (c) 2011, 2016 IBM Corporation and others.
 *
 * This Example Content is intended to demonstrate
 * usage of Eclipse technology. It is provided to you under the terms and
 * conditions of the Eclipse Distribution License v1.0 which is available
 * at http://www.eclipse.org/org/documents/edl-v10.php
 *
 * Contributors:
 *     IBM Corporation - initial API and implementation
 *******************************************************************************/
package org.eclipse.swt.snippets;

/*
 * Tree example snippet: determine which TreeItems are visible in a Tree's viewport
 *
 * For a list of all SWT example snippets see
 * http://www.eclipse.org/swt/snippets/
 */
import org.eclipse.swt.*;
import org.eclipse.swt.graphics.*;
import org.eclipse.swt.layout.*;
import org.eclipse.swt.widgets.*;

public class Snippet358 {

    public static void main(String[] args) {
        Display display = new Display();
        Shell shell = new Shell(display);
        shell.setText("Snippet 358");
        shell.setLayout(new GridLayout());
        final Tree tree = new Tree(shell, SWT.NONE);
        tree.setLayoutData(new GridData(200, 200));
        for (int i = 0; i < 9; i++) {
            TreeItem item = new TreeItem(tree, SWT.NONE);
            item.setText("root-level item " + i);
            for (int j = 0; j < 9; j++) {
                new TreeItem(item, SWT.NONE).setText("item " + i + "-" + j);
            }
        }

        Button button = new Button(shell, SWT.PUSH);
        button.setText("Print item visibilities");
        button.addListener(SWT.Selection, event -> {
            Rectangle treeBounds = new Rectangle(0, 0, 0, 0);
            Point treeSize = tree.getSize();
            treeBounds.width = treeSize.x;
            treeBounds.height = treeSize.y;
            TreeItem[] rootItems = tree.getItems();
            for (int i = 0; i < rootItems.length; i++) {
                TreeItem rootItem = rootItems[i];
                System.out.println(rootItem.getText() + " is at least partially visible? "
                        + treeBounds.intersects(rootItem.getBounds()));
                TreeItem[] childItems = rootItem.getItems();
                for (int j = 0; j < childItems.length; j++) {
                    TreeItem childItem = childItems[j];
                    System.out.println(childItem.getText() + " is at least partially visible? "
                            + treeBounds.intersects(childItem.getBounds()));
                }
            }
        });

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

}