EDIT

/*******************************************************************************

 * Copyright (c) 2000, 2010 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 java.beans.PropertyChangeEvent;

import java.beans.PropertyChangeListener;

import org.eclipse.draw2d.ConnectionLayer;

import org.eclipse.draw2d.FreeformLayer;

import org.eclipse.draw2d.FreeformLayeredPane;

import org.eclipse.draw2d.FreeformViewport;

import org.eclipse.draw2d.IFigure;

import org.eclipse.draw2d.LayeredPane;

import org.eclipse.draw2d.geometry.Dimension;

import org.eclipse.draw2d.geometry.Point;

import org.eclipse.gef.AutoexposeHelper;

import org.eclipse.gef.DragTracker;

import org.eclipse.gef.EditPart;

import org.eclipse.gef.EditPartViewer;

import org.eclipse.gef.LayerConstants;

import org.eclipse.gef.Request;

import org.eclipse.gef.SnapToGrid;

import org.eclipse.gef.tools.MarqueeDragTracker;

/**

 * A graphical root that uses {@link org.eclipse.draw2d.FreeformFigure

 * FreeformFigures} as the layers in the diagram. The

 * {@link EditPartViewer#setContents(EditPart) contents} editpart must provide a

 * FreeformFigure as its figure. Freeform figures are special because they can

 * expand in any direction. This allows the user to drag objects or bendpoints

 * into the negative X and Y coordinates of a diagram. If this feature is not

 * being used, clients should use the {@link FreeformGraphicalRootEditPart} as

 * their viewer's root editpart.

 * <P>

 * <EM>IMPORTANT:</EM> The contents editpart that is added to a freeform root

 * should have a <code>FreeformFigure</code> (such as FreeformLayer) as its

 * Figure. The primary layer is <EM>not</EM> using a draw2d LayoutManager, and

 * will not size the contents' figure properly unless it is a freeform figure.

 * <P>

 * <EM>IMPORTANT:</EM>The freeform root uses a <code>FreeformViewport</code> as

 * its primary figure. This class must be used with the

 * {@link org.eclipse.gef.ui.parts.ScrollingGraphicalViewer}. The viewport gets

 * installed into that viewer's {@link org.eclipse.draw2d.FigureCanvas}, which

 * provides native scrollbars for scrolling the viewport.

 * <P>

 * This root serves as the diagram's

 * {@link org.eclipse.gef.editparts.LayerManager}, providing the following layer

 * structure, in top-to-bottom order:

 * <table cellspacing="0" cellpadding="0">

 * <tr>

 * <td colspan="2">Root Freeform Layered Pane</td>

 * </tr>

 * <tr>

 * <td>&#9500;</td>

 * <td>&nbsp;Feedback Layer</td>

 * </tr>

 * <tr>

 * <td>&#9500;</td>

 * <td>&nbsp;Handle Layer</td>

 * </tr>

 * <tr>

 * <td>&#9492;</td>

 * <td>&nbsp;Printable Layers</td>

 * </tr>

 * <tr>

 * <td>&nbsp;</td>

 * <td>&#9500; Connection Layer</td>

 * </tr>

 * <tr>

 * <td>&nbsp;</td>

 * <td>&#9492; Primary Layer</td>

 * </tr>

 * </table>

 * 

 */

public class FreeformGraphicalRootEditPart extends SimpleRootEditPart implements

		LayerConstants, LayerManager {

	private LayeredPane innerLayers;

	private LayeredPane printableLayers;

	private PropertyChangeListener gridListener = new PropertyChangeListener() {

		public void propertyChange(PropertyChangeEvent evt) {

			String property = evt.getPropertyName();

			if (property.equals(SnapToGrid.PROPERTY_GRID_ORIGIN)

					|| property.equals(SnapToGrid.PROPERTY_GRID_SPACING)

					|| property.equals(SnapToGrid.PROPERTY_GRID_VISIBLE))

				refreshGridLayer();

		}

	};

	/**

	 * @see org.eclipse.gef.editparts.AbstractGraphicalEditPart#createFigure()

	 */

	protected IFigure createFigure() {

		FreeformViewport viewport = new FreeformViewport();

		innerLayers = new FreeformLayeredPane();

		createLayers(innerLayers);

		viewport.setContents(innerLayers);

		return viewport;

	}

	/**

	 * Creates a {@link GridLayer grid}. Sub-classes can override this method to

	 * customize the appearance of the grid. The grid layer should be the first

	 * layer (i.e., beneath the primary layer) if it is not to cover up parts on

	 * the primary layer. In that case, the primary layer should be transparent

	 * so that the grid is visible.

	 * 

	 * @return the newly created GridLayer

	 */

	protected GridLayer createGridLayer() {

		return new GridLayer();

	}

	/**

	 * Creates the top-most set of layers on the given layered pane.

	 * 

	 * @param layeredPane

	 *            the parent for the created layers

	 */

	protected void createLayers(LayeredPane layeredPane) {

		layeredPane.add(createGridLayer(), GRID_LAYER);

		layeredPane.add(getPrintableLayers(), PRINTABLE_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 printed.

	 * 

	 * @see org.eclipse.gef.print.PrintGraphicalViewerOperation

	 * @return a new LayeredPane containing the printable layers

	 */

	protected LayeredPane createPrintableLayers() {

		FreeformLayeredPane layeredPane = new FreeformLayeredPane();

		layeredPane.add(new FreeformLayer(), PRIMARY_LAYER);

		layeredPane.add(new ConnectionLayer(), CONNECTION_LAYER);

		return layeredPane;

	}

	/**

	 * @see org.eclipse.core.runtime.IAdaptable#getAdapter(java.lang.Class)

	 */

	public Object getAdapter(Class adapter) {

		if (adapter == AutoexposeHelper.class)

			return new ViewportAutoexposeHelper(this);

		return super.getAdapter(adapter);

	}

	/**

	 * The contents' Figure will be added to the PRIMARY_LAYER.

	 * 

	 * @see org.eclipse.gef.GraphicalEditPart#getContentPane()

	 */

	public IFigure getContentPane() {

		return getLayer(PRIMARY_LAYER);

	}

	/**

	 * Should not be called, but returns a MarqeeDragTracker for good measure.

	 * 

	 * @see org.eclipse.gef.EditPart#getDragTracker(org.eclipse.gef.Request)

	 */

	public DragTracker getDragTracker(Request req) {

		/*

		 * The root will only be asked for a drag tracker if for some reason the

		 * contents editpart says it is neither selector nor opaque.

		 */

		return new MarqueeDragTracker();

	}

	/**

	 * Returns the layer indicated by the key. Searches all layered panes.

	 * 

	 * @see LayerManager#getLayer(Object)

	 */

	public IFigure getLayer(Object key) {

		if (innerLayers == null)

			return null;

		IFigure layer = innerLayers.getLayer(key);

		if (layer != null)

			return layer;

		if (printableLayers == null)

			return null;

		return printableLayers.getLayer(key);

	}

	/**

	 * The root editpart does not have a real model. The LayerManager ID is

	 * returned so that this editpart gets registered using that key.

	 * 

	 * @see org.eclipse.gef.EditPart#getModel()

	 */

	public Object getModel() {

		return LayerManager.ID;

	}

	/**

	 * Returns the LayeredPane that should be used during printing. This layer

	 * will be identified using {@link LayerConstants#PRINTABLE_LAYERS}.

	 * 

	 * @return the layered pane containing all printable content

	 */

	protected LayeredPane getPrintableLayers() {

		if (printableLayers == null)

			printableLayers = createPrintableLayers();

		return printableLayers;

	}

	/**

	 * Updates the {@link GridLayer grid} based on properties set on the

	 * {@link #getViewer() graphical viewer}:

	 * {@link SnapToGrid#PROPERTY_GRID_VISIBLE},

	 * {@link SnapToGrid#PROPERTY_GRID_SPACING}, and

	 * {@link SnapToGrid#PROPERTY_GRID_ORIGIN}.

	 * <p>

	 * This method is invoked initially when the GridLayer is created, and when

	 * any of the above-mentioned properties are changed on the viewer.

	 */

	protected void refreshGridLayer() {

		boolean visible = false;

		GridLayer grid = (GridLayer) getLayer(GRID_LAYER);

		Boolean val = (Boolean) getViewer().getProperty(

				SnapToGrid.PROPERTY_GRID_VISIBLE);

		if (val != null)

			visible = val.booleanValue();

		grid.setOrigin((Point) getViewer().getProperty(

				SnapToGrid.PROPERTY_GRID_ORIGIN));

		grid.setSpacing((Dimension) getViewer().getProperty(

				SnapToGrid.PROPERTY_GRID_SPACING));

		grid.setVisible(visible);

	}

	/**

	 * @see org.eclipse.gef.editparts.AbstractEditPart#register()

	 */

	protected void register() {

		super.register();

		if (getLayer(GRID_LAYER) != null) {

			getViewer().addPropertyChangeListener(gridListener);

			refreshGridLayer();

		}

	}

	/**

	 * @see AbstractEditPart#unregister()

	 */

	protected void unregister() {

		getViewer().removePropertyChangeListener(gridListener);

		super.unregister();

	}

	class FeedbackLayer extends FreeformLayer {

		FeedbackLayer() {

			setEnabled(false);

		}

	}

}