/*******************************************************************************
 * Copyright (c) 2007, 2009 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.ui.internal.views.markers;

import org.eclipse.jface.viewers.TreeViewer;
import org.eclipse.swt.widgets.Composite;
import org.eclipse.swt.widgets.Item;
import org.eclipse.swt.widgets.Tree;

/**
 * The MarkersTreeViewer is a viewer that optimizes the expandToLevel method.
 *
 * @since 3.4
 *
 */

public class MarkersTreeViewer extends TreeViewer {

	/**
	 * Create a new instance of the receiver.
	 *
	 * @param parent
	 * @param style
	 */
	public MarkersTreeViewer(Composite parent, int style) {
		super(parent, style);

	}

	/**
	 * Create a new instance of the receiver.
	 *
	 * @param parent
	 */
	public MarkersTreeViewer(Composite parent) {
		super(parent);
	}

	/**
	 * Create a new instance of the receiver.
	 *
	 * @param tree
	 */
	public MarkersTreeViewer(Tree tree) {
		super(tree);
	}

	/**
	 * Remove all of the entries and unmap all of the elements.
	 */
	public void removeAndClearAll() {
		removeAll(getControl());
		unmapAllElements();
	}

	/*
	 * (non-Javadoc)
	 *
	 * @see
	 * org.eclipse.jface.viewers.AbstractTreeViewer#doUpdateItem(org.eclipse
	 * .swt.widgets.Item, java.lang.Object)
	 */
	@Override
	protected void doUpdateItem(Item item, Object element) {
		super.doUpdateItem(item, element);
		/*
		 * For performance reasons clear cache of the item used in updating UI.
		 */
		MarkerSupportItem cellItem = (MarkerSupportItem) element;
		if (cellItem.isConcrete())
			cellItem.clearCache();
	}

}