ScalableFreeformRootEditPart.java

/*******************************************************************************
 * Copyright (c) 2000, 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
 *******************************************************************************/
package org.eclipse.gef.editparts;

import org.eclipse.draw2d.FreeformLayer;
import org.eclipse.draw2d.IFigure;
import org.eclipse.draw2d.LayeredPane;
import org.eclipse.draw2d.ScalableFigure;
import org.eclipse.draw2d.ScalableFreeformLayeredPane;
import org.eclipse.draw2d.Viewport;

/**
 * Adds Zoom support to the standard FreeformGraphicalRootEditPart.  This root is just 
 * like its superclass, except it inserts a new <code>LayeredPane</code> above the 
 * printable layers.  This pane is identified with the 
 * {@link org.eclipse.gef.LayerConstants#SCALABLE_LAYERS} ID.  This root also provides a
 * ZoomManager, for optional use with the {@link
 * org.eclipse.gef.ui.actions.ZoomComboContributionItem}
 * <P>
 * The structure of layers (top-to-bottom) for this root is:
 * <table cellspacing="0" cellpadding="0">
 *   <tr>
 *     <td colspan="4">Root Freeform Layered Pane</td>
 *   </tr>
 *   <tr>
 *     <td>├</td>
 *     <td colspan="3"> Guide Layer</td>
 *   </tr>
 *   <tr>
 *     <td>├</td>
 *     <td colspan="3"> Feedback Layer</td>
 *   </tr>
 *   <tr>
 *     <td>├</td>
 *     <td colspan="3"> Handle Layer</td>
 *   </tr>
 *   <tr>
 *     <td>└</td>
 *     <td colspan="2"> <b>Scalable Layers</b></td>
 *     <td>({@link ScalableFreeformLayeredPane})</td>
 *   </tr>
 *   <tr>
 *     <td> </td>
 *     <td>├</td>
 *     <td colspan="2"> Scaled Feedback Layer</td>
 *   </tr>
 *   <tr>
 *     <td> </td>
 *     <td>├</td>
 *     <td colspan="2"> Printable Layers</td>
 *   </tr>
 *   <tr>
 *     <td> </td>
 *     <td> </td>
 *     <td>├ Connection Layer</td>
 *   </tr>
 *   <tr>
 *     <td> </td>
 *     <td> </td>
 *     <td>└ Primary Layer</td>
 *     <td> </td>
 *   </tr>
 *   <tr>
 *     <td> </td>
 *     <td>└</td>
 *     <td colspan="2"> Grid Layer</td>
 *   </tr>
 * </table>
 * 
 * @author hudsonr
 * @since 2.1
 */
public class ScalableFreeformRootEditPart
	extends FreeformGraphicalRootEditPart
{

private ScalableFreeformLayeredPane scaledLayers;
private ZoomManager zoomManager;

/**
 * Constructor for ScalableFreeformRootEditPart
 */
public ScalableFreeformRootEditPart() {
	zoomManager = new ZoomManager((ScalableFigure)getScaledLayers(),
									((Viewport)getFigure()));
}

/**
 * @see FreeformGraphicalRootEditPart#createLayers(LayeredPane)
 */
protected void createLayers(LayeredPane layeredPane) {
	layeredPane.add(getScaledLayers(), SCALABLE_LAYERS);
	layeredPane.add(new FreeformLayer(), HANDLE_LAYER);
	layeredPane.add(new FeedbackLayer(), FEEDBACK_LAYER);
	layeredPane.add(new GuideLayer(), GUIDE_LAYER);
}

/**
 * Creates a layered pane and the layers that should be scaled.
 * @return a new freeform layered pane containing the scalable layers
 */
protected ScalableFreeformLayeredPane createScaledLayers() {
	ScalableFreeformLayeredPane layers = new ScalableFreeformLayeredPane();
	layers.add(createGridLayer(), GRID_LAYER);
	layers.add(getPrintableLayers(), PRINTABLE_LAYERS);
	layers.add(new FeedbackLayer(), SCALED_FEEDBACK_LAYER);
	return layers;
}

/**
 * @see FreeformGraphicalRootEditPart#getLayer(Object)
 */
public IFigure getLayer(Object key) {
	IFigure layer = scaledLayers.getLayer(key);
	if (layer != null)
		return layer;
	return super.getLayer(key);
}

/**
 * Returns the scalable layers of this EditPart
 * @return LayeredPane
 */
protected LayeredPane getScaledLayers() {
	if (scaledLayers == null)
		scaledLayers = createScaledLayers();
	return scaledLayers;
}

/**
 * Returns the zoomManager.
 * @return ZoomManager
 */
public ZoomManager getZoomManager() {
	return zoomManager;
}

/**
 * @see org.eclipse.gef.editparts.AbstractEditPart#register()
 */
protected void register() {
	super.register();
	getViewer().setProperty(ZoomManager.class.toString(), getZoomManager());
}

/**
 * @see org.eclipse.gef.editparts.AbstractEditPart#unregister()
 */
protected void unregister() {
	super.unregister();
	getViewer().setProperty(ZoomManager.class.toString(), null);
}

}