/*******************************************************************************
 * Copyright (c) 2001, 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
 *     Jens Lukowski/Innoopract - initial renaming/restructuring
 *     
 *******************************************************************************/
package org.eclipse.wst.sse.ui.internal.selection;

import org.eclipse.jface.text.IRegion;
import org.eclipse.jface.text.Region;
import org.eclipse.ui.texteditor.IUpdate;
import org.eclipse.wst.sse.core.internal.provisional.IndexedRegion;
import org.eclipse.wst.sse.ui.StructuredTextEditor;
import org.eclipse.wst.sse.ui.internal.SSEUIMessages;
import org.w3c.dom.Node;

public class StructureSelectHistoryAction extends StructureSelectAction implements IUpdate {
	public StructureSelectHistoryAction(StructuredTextEditor editor) {
		super(editor);
		setText(SSEUIMessages.StructureSelectHistory_label); //$NON-NLS-1$
		setToolTipText(SSEUIMessages.StructureSelectHistory_tooltip); //$NON-NLS-1$
		setDescription(SSEUIMessages.StructureSelectHistory_description); //$NON-NLS-1$

		update();
	}

	protected IndexedRegion getCursorIndexedRegion() {
		return null;
	}

	protected Region getNewSelectionRegion(Node node, Region region) {
		return null;
	}

	public void run() {
		IRegion old = fHistory.getLast();
		if (old != null) {
			try {
				fHistory.ignoreSelectionChanges();
				fEditor.selectAndReveal(old.getOffset(), old.getLength());
			} finally {
				fHistory.listenToSelectionChanges();
			}
		}
	}

	public void update() {
		setEnabled(!fHistory.isEmpty());
	}
}