org.eclipse.swt.snippets.Snippet274.java Source code

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Here is the source code for org.eclipse.swt.snippets.Snippet274.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;

/*
 * Tree snippet: implement standard tree check box behavior (SWT.CHECK)
 *
 * For a list of all SWT example snippets see
 * http://www.eclipse.org/swt/snippets/
 *
 * @since 3.3
 */
import org.eclipse.swt.*;
import org.eclipse.swt.graphics.*;
import org.eclipse.swt.widgets.*;

public class Snippet274 {

    static void checkPath(TreeItem item, boolean checked, boolean grayed) {
        if (item == null)
            return;
        if (grayed) {
            checked = true;
        } else {
            int index = 0;
            TreeItem[] items = item.getItems();
            while (index < items.length) {
                TreeItem child = items[index];
                if (child.getGrayed() || checked != child.getChecked()) {
                    checked = grayed = true;
                    break;
                }
                index++;
            }
        }
        item.setChecked(checked);
        item.setGrayed(grayed);
        checkPath(item.getParentItem(), checked, grayed);
    }

    static void checkItems(TreeItem item, boolean checked) {
        item.setGrayed(false);
        item.setChecked(checked);
        TreeItem[] items = item.getItems();
        for (int i = 0; i < items.length; i++) {
            checkItems(items[i], checked);
        }
    }

    public static void main(String[] args) {
        Display display = new Display();
        Shell shell = new Shell(display);
        shell.setText("Snippet 274");
        Tree tree = new Tree(shell, SWT.BORDER | SWT.CHECK);
        tree.addListener(SWT.Selection, event -> {
            if (event.detail == SWT.CHECK) {
                TreeItem item = (TreeItem) event.item;
                boolean checked = item.getChecked();
                checkItems(item, checked);
                checkPath(item.getParentItem(), checked, false);
            }
        });
        for (int i = 0; i < 4; i++) {
            TreeItem itemI = new TreeItem(tree, SWT.NONE);
            itemI.setText("Item " + i);
            for (int j = 0; j < 4; j++) {
                TreeItem itemJ = new TreeItem(itemI, SWT.NONE);
                itemJ.setText("Item " + i + " " + j);
                for (int k = 0; k < 4; k++) {
                    TreeItem itemK = new TreeItem(itemJ, SWT.NONE);
                    itemK.setText("Item " + i + " " + j + " " + k);
                }
            }
        }
        Rectangle clientArea = shell.getClientArea();
        tree.setBounds(clientArea.x, clientArea.y, 200, 200);
        shell.pack();
        shell.open();
        while (!shell.isDisposed()) {
            if (!display.readAndDispatch())
                display.sleep();
        }
        display.dispose();
    }

}