org.jboss.tools.openshift.express.internal.ui.utils.TreeUtils.java Source code

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Here is the source code for org.jboss.tools.openshift.express.internal.ui.utils.TreeUtils.java

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/*******************************************************************************
 * Copyright (c) 2011 Red Hat, Inc.
 * Distributed under license by Red Hat, Inc. All rights reserved.
 * This program is 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:
 *     Red Hat, Inc. - initial API and implementation
 ******************************************************************************/
package org.jboss.tools.openshift.express.internal.ui.utils;

import org.eclipse.core.runtime.Assert;
import org.eclipse.jface.viewers.ViewerCell;
import org.eclipse.swt.SWT;
import org.eclipse.swt.custom.TreeEditor;
import org.eclipse.swt.events.DisposeEvent;
import org.eclipse.swt.events.DisposeListener;
import org.eclipse.swt.widgets.Control;
import org.eclipse.swt.widgets.Event;
import org.eclipse.swt.widgets.Listener;
import org.eclipse.swt.widgets.Tree;
import org.eclipse.swt.widgets.TreeItem;

/**
 * @author Andr Dietisheim
 */
public class TreeUtils {

    /**
     * Creates a tree editor for the given cell with the given control.
     * <p>
     * A tree editor puts a control over a given cell in a tree. Furthermore it puts text into the cell so that the
     * column's large enough so that the control has enough room to overlay itself over it
     * 
     * @param cell the cell to put the control to
     * @param control the control to put to the given cell
     * @param cellText the text that's put into the table cell (overlayed by the editor), that only enlarges the
     *            column to have enough room for the editor
     * 
     * @return the tree editor
     * 
     * @see ViewerCell
     * @see TreeEditor
     */
    public static TreeEditor createTreeEditor(Control control, String cellText, ViewerCell cell) {
        Assert.isTrue(cell.getControl() instanceof Tree);

        Tree tree = (Tree) cell.getControl();
        final TreeEditor treeEditor = new TreeEditor(tree);
        initializeTreeEditor(treeEditor, control, cellText, cell);
        tree.addDisposeListener(new DisposeListener() {

            @Override
            public void widgetDisposed(DisposeEvent e) {
                treeEditor.dispose();
            }
        });
        return treeEditor;
    }

    /**
     * Initializes a given tree editor for a given viewer cell with a given (editor-)control.
     * 
     * @param treeEditor the tree editor that shall get initialized
     * @param control the control that shall be positioned by the tree editor
     * @param cellText the text that will get displayed in the cell (only used to make sure, the cell has the required size)
     * @param cell the cell the table editor shall be positioned to.
     * 
     * @see TreeEditor
     * @see ViewerCell
     */
    public static void initializeTreeEditor(TreeEditor treeEditor, Control control, String cellText,
            ViewerCell cell) {
        treeEditor.grabHorizontal = true;
        treeEditor.grabVertical = true;
        treeEditor.horizontalAlignment = SWT.FILL;
        treeEditor.verticalAlignment = SWT.FILL;
        TreeItem treeItem = (TreeItem) cell.getItem();
        treeEditor.setEditor(control, treeItem, cell.getColumnIndex());
        // ensure cell is as large as space needed for link
        //cell.setText( " " + cellText + " ");
    }

    /**
     * Sets the height of the rows in a given table. The height might only be increased (compared to the standard
     * height). Decreasing it below the default height has no effect.
     * 
     * @param height the height in pixels
     * @param table the table
     */
    public static void setRowHeight(final int height, Tree tree) {
        tree.addListener(SWT.MeasureItem, new Listener() {
            public void handleEvent(Event event) {
                event.height = height;
            }
        });
    }
}