ZoomCommand.java

/*******************************************************************************
 * Copyright (c) 2010 Oak Ridge National Laboratory.
 * 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
 ******************************************************************************/
package org.eclipse.nebula.visualization.internal.xygraph.undo;

import java.util.ArrayList;
import java.util.List;

import org.eclipse.nebula.visualization.xygraph.figures.Axis;
import org.eclipse.nebula.visualization.xygraph.linearscale.Range;

/**
 * The command for graph zooming and panning.
 * 
 * @author Xihui Chen
 * @author Kay Kasemir (allow <code>null</code> for x axis)
 */
public class ZoomCommand extends SaveStateCommand {
	final private List<Axis> xAxisList;
	final private List<Axis> yAxisList;

	final private List<Range> beforeXRangeList = new ArrayList<Range>();
	final private List<Range> beforeYRangeList = new ArrayList<Range>();
	final private List<Range> afterXRangeList = new ArrayList<Range>();
	final private List<Range> afterYRangeList = new ArrayList<Range>();

	/**
	 * Initialize
	 * 
	 * @param name
	 *            Name of operation for undo/redo GUI
	 * @param xAxisList
	 *            X Axes to save or <code>null</code>
	 * @param yAxisList
	 *            Y Axes to save
	 */
	public ZoomCommand(final String name, final List<Axis> xAxisList, final List<Axis> yAxisList) {
		super(name);
		this.xAxisList = xAxisList;
		this.yAxisList = yAxisList;
		saveOriginalState();
	}

	private void saveOriginalState() {
		if (xAxisList != null)
			for (Axis axis : xAxisList)
				beforeXRangeList.add(axis.getRange());
		for (Axis axis : yAxisList)
			beforeYRangeList.add(axis.getRange());
	}

	public void redo() {
		int i = 0;
		if (xAxisList != null) {
			for (Axis axis : xAxisList) {
				axis.setRange(afterXRangeList.get(i));
				i++;
			}
		}
		i = 0;
		for (Axis axis : yAxisList) {
			axis.setRange(afterYRangeList.get(i));
			i++;
		}
	}

	public void undo() {
		int i = 0;
		if (xAxisList != null) {
			for (Axis axis : xAxisList) {
				axis.setRange(beforeXRangeList.get(i));
				i++;
			}
		}
		i = 0;
		for (Axis axis : yAxisList) {
			axis.setRange(beforeYRangeList.get(i));
			i++;
		}
	}

	@Override
	public void saveState() {
		if (xAxisList != null)
			for (Axis axis : xAxisList)
				afterXRangeList.add(axis.getRange());
		for (Axis axis : yAxisList)
			afterYRangeList.add(axis.getRange());
	}
}