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.editpolicies;

import java.util.ArrayList;

import java.util.List;

import org.eclipse.draw2d.ColorConstants;

import org.eclipse.draw2d.Cursors;

import org.eclipse.draw2d.FigureUtilities;

import org.eclipse.draw2d.FocusBorder;

import org.eclipse.draw2d.Graphics;

import org.eclipse.draw2d.IFigure;

import org.eclipse.draw2d.Locator;

import org.eclipse.draw2d.PositionConstants;

import org.eclipse.draw2d.RectangleFigure;

import org.eclipse.draw2d.geometry.PrecisionRectangle;

import org.eclipse.draw2d.geometry.Rectangle;

import org.eclipse.gef.DragTracker;

import org.eclipse.gef.GraphicalEditPart;

import org.eclipse.gef.Request;

import org.eclipse.gef.RequestConstants;

import org.eclipse.gef.SharedCursors;

import org.eclipse.gef.commands.Command;

import org.eclipse.gef.handles.AbstractHandle;

import org.eclipse.gef.handles.HandleBounds;

import org.eclipse.gef.handles.NonResizableHandleKit;

import org.eclipse.gef.handles.ResizableHandleKit;

import org.eclipse.gef.requests.AlignmentRequest;

import org.eclipse.gef.requests.ChangeBoundsRequest;

import org.eclipse.gef.tools.DragEditPartsTracker;

import org.eclipse.gef.tools.ResizeTracker;

import org.eclipse.gef.tools.SelectEditPartTracker;

/**

 * Provide support for selecting and positioning a non-resizable editpart.

 * Selection is indicated via four square handles at each corner of the

 * editpart's figure, and a rectangular handle that outlines the editpart with a

 * 1-pixel black line. All of these handles return

 * {@link org.eclipse.gef.tools.DragEditPartsTracker}s, which allows the current

 * selection to be dragged.

 * <P>

 * During feedback, a rectangle filled using XOR and outlined with dashes is

 * drawn. Subclasses can tailor the feedback.

 * 

 * @author hudsonr

 */

public class NonResizableEditPolicy extends SelectionHandlesEditPolicy {

	private IFigure focusRect;

	private IFigure feedback;

	private boolean isDragAllowed = true;

	/**

	 * Creates the figure used for feedback.

	 * 

	 * @return the new feedback figure

	 */

	protected IFigure createDragSourceFeedbackFigure() {

		// Use a ghost rectangle for feedback

		RectangleFigure r = new RectangleFigure();

		FigureUtilities.makeGhostShape(r);

		r.setLineStyle(Graphics.LINE_DOT);

		r.setForegroundColor(ColorConstants.white);

		r.setBounds(getInitialFeedbackBounds());

		addFeedback(r);

		return r;

	}

	/**

	 * @see org.eclipse.gef.editpolicies.SelectionHandlesEditPolicy#createSelectionHandles()

	 */

	protected List createSelectionHandles() {

		List list = new ArrayList();

		createMoveHandle(list);

		createDragHandle(list, PositionConstants.NORTH_EAST);

		createDragHandle(list, PositionConstants.NORTH_WEST);

		createDragHandle(list, PositionConstants.SOUTH_EAST);

		createDragHandle(list, PositionConstants.SOUTH_WEST);

		return list;

	}

	/**

	 * Creates a 'resize'/'drag' handle, which uses a

	 * {@link DragEditPartsTracker} in case {@link #isDragAllowed()} returns

	 * true, and a {@link SelectEditPartTracker} otherwise.

	 * 

	 * @param handles

	 *            The list of handles to add the resize handle to

	 * @param direction

	 *            A position constant indicating the direction to create the

	 *            handle for

	 * @since 3.7

	 */

	protected void createDragHandle(List handles, int direction) {

		if (isDragAllowed()) {

			// display 'resize' handles to allow dragging (drag tracker)

			NonResizableHandleKit

					.addHandle((GraphicalEditPart) getHost(), handles,

							direction, getDragTracker(), SharedCursors.SIZEALL);

		} else {

			// display 'resize' handles to indicate selection only (selection

			// tracker)

			NonResizableHandleKit

					.addHandle((GraphicalEditPart) getHost(), handles,

							direction, getSelectTracker(), SharedCursors.ARROW);

		}

	}

	/**

	 * Returns a selection tracker to use by a selection handle.

	 * 

	 * @return a new {@link ResizeTracker}

	 * @since 3.7

	 */

	protected SelectEditPartTracker getSelectTracker() {

		return new SelectEditPartTracker(getHost());

	}

	/**

	 * Returns a drag tracker to use by a resize handle.

	 * 

	 * @return a new {@link ResizeTracker}

	 * @since 3.7

	 */

	protected DragEditPartsTracker getDragTracker() {

		return new DragEditPartsTracker(getHost());

	}

	/**

	 * Creates a 'move' handle, which uses a {@link DragEditPartsTracker} in

	 * case {@link #isDragAllowed()} returns true, and a

	 * {@link SelectEditPartTracker} otherwise.

	 * 

	 * @param handles

	 *            The list of handles to add the move handle to.

	 * @since 3.7

	 */

	protected void createMoveHandle(List handles) {

		if (isDragAllowed()) {

			// display 'move' handle to allow dragging

			ResizableHandleKit.addMoveHandle((GraphicalEditPart) getHost(),

					handles, getDragTracker(), Cursors.SIZEALL);

		} else {

			// display 'move' handle only to indicate selection

			ResizableHandleKit.addMoveHandle((GraphicalEditPart) getHost(),

					handles, getSelectTracker(), SharedCursors.ARROW);

		}

	}

	/**

	 * @see org.eclipse.gef.EditPolicy#deactivate()

	 */

	public void deactivate() {

		if (feedback != null) {

			removeFeedback(feedback);

			feedback = null;

		}

		hideFocus();

		super.deactivate();

	}

	/**

	 * Erases drag feedback. This method called whenever an erase feedback

	 * request is received of the appropriate type.

	 * 

	 * @param request

	 *            the request

	 */

	protected void eraseChangeBoundsFeedback(ChangeBoundsRequest request) {

		if (feedback != null) {

			removeFeedback(feedback);

		}

		feedback = null;

	}

	/**

	 * @see org.eclipse.gef.EditPolicy#eraseSourceFeedback(org.eclipse.gef.Request)

	 */

	public void eraseSourceFeedback(Request request) {

		if ((REQ_MOVE.equals(request.getType()) && isDragAllowed())

				|| REQ_CLONE.equals(request.getType())

				|| REQ_ADD.equals(request.getType()))

			eraseChangeBoundsFeedback((ChangeBoundsRequest) request);

	}

	/**

	 * @see org.eclipse.gef.EditPolicy#getCommand(org.eclipse.gef.Request)

	 */

	public Command getCommand(Request request) {

		Object type = request.getType();

		if (REQ_MOVE.equals(type) && isDragAllowed())

			return getMoveCommand((ChangeBoundsRequest) request);

		if (REQ_ORPHAN.equals(type))

			return getOrphanCommand(request);

		if (REQ_ALIGN.equals(type))

			return getAlignCommand((AlignmentRequest) request);

		return null;

	}

	/**

	 * Lazily creates and returns the feedback figure used during drags.

	 * 

	 * @return the feedback figure

	 */

	protected IFigure getDragSourceFeedbackFigure() {

		if (feedback == null)

			feedback = createDragSourceFeedbackFigure();

		return feedback;

	}

	/**

	 * Returns the command contribution to an alignment request

	 * 

	 * @param request

	 *            the alignment request

	 * @return the contribution to the alignment

	 */

	protected Command getAlignCommand(AlignmentRequest request) {

		AlignmentRequest req = new AlignmentRequest(REQ_ALIGN_CHILDREN);

		req.setEditParts(getHost());

		req.setAlignment(request.getAlignment());

		req.setAlignmentRectangle(request.getAlignmentRectangle());

		return getHost().getParent().getCommand(req);

	}

	/**

	 * Returns the bounds of the host's figure by reference to be used to

	 * calculate the initial location of the feedback. The returned Rectangle

	 * should not be modified. Uses handle bounds if available.

	 * 

	 * @return the host figure's bounding Rectangle

	 */

	protected Rectangle getInitialFeedbackBounds() {

		if (((GraphicalEditPart) getHost()).getFigure() instanceof HandleBounds)

			return ((HandleBounds) ((GraphicalEditPart) getHost()).getFigure())

					.getHandleBounds();

		return ((GraphicalEditPart) getHost()).getFigure().getBounds();

	}

	/**

	 * Returns the command contribution to a change bounds request. The

	 * implementation actually redispatches the request to the host's parent

	 * editpart as a {@link RequestConstants#REQ_MOVE_CHILDREN} request. The

	 * parent's contribution is returned.

	 * 

	 * @param request

	 *            the change bounds request

	 * @return the command contribution to the request

	 */

	protected Command getMoveCommand(ChangeBoundsRequest request) {

		ChangeBoundsRequest req = new ChangeBoundsRequest(REQ_MOVE_CHILDREN);

		req.setEditParts(getHost());

		req.setMoveDelta(request.getMoveDelta());

		req.setSizeDelta(request.getSizeDelta());

		req.setLocation(request.getLocation());

		req.setExtendedData(request.getExtendedData());

		return getHost().getParent().getCommand(req);

	}

	/**

	 * Subclasses may override to contribute to the orphan request. By default,

	 * <code>null</code> is returned to indicate no participation. Orphan

	 * requests are not forwarded to the host's parent here. That is done in

	 * {@link ComponentEditPolicy}. So, if the host has a component editpolicy,

	 * then the parent will already have a chance to contribute.

	 * 

	 * @param req

	 *            the orphan request

	 * @return <code>null</code> by default

	 */

	protected Command getOrphanCommand(Request req) {

		return null;

	}

	/**

	 * Hides the focus rectangle displayed in <code>showFocus()</code>.

	 * 

	 * @see #showFocus()

	 * @see org.eclipse.gef.editpolicies.SelectionEditPolicy#hideFocus()

	 */

	protected void hideFocus() {

		if (focusRect != null)

			removeFeedback(focusRect);

		focusRect = null;

	}

	/**

	 * Returns true if this EditPolicy allows its EditPart to be dragged.

	 * 

	 * @return true if the EditPart can be dragged.

	 */

	public boolean isDragAllowed() {

		return isDragAllowed;

	}

	/**

	 * Sets the dragability of the EditPolicy to the given value. If the value

	 * is false, the EditPolicy should not allow its EditPart to be dragged.

	 * 

	 * @param isDragAllowed

	 *            whether or not the EditPolicy can be dragged.

	 */

	public void setDragAllowed(boolean isDragAllowed) {

		if (isDragAllowed == this.isDragAllowed)

			return;

		this.isDragAllowed = isDragAllowed;

	}

	/**

	 * Shows or updates feedback for a change bounds request.

	 * 

	 * @param request

	 *            the request

	 */

	protected void showChangeBoundsFeedback(ChangeBoundsRequest request) {

		IFigure feedback = getDragSourceFeedbackFigure();

		PrecisionRectangle rect = new PrecisionRectangle(

				getInitialFeedbackBounds().getCopy());

		getHostFigure().translateToAbsolute(rect);

		rect.translate(request.getMoveDelta());

		rect.resize(request.getSizeDelta());

		feedback.translateToRelative(rect);

		feedback.setBounds(rect);

	}

	/**

	 * Shows a focus rectangle around the host's figure. The focus rectangle is

	 * expanded by 5 pixels from the figure's bounds.

	 * 

	 * @see org.eclipse.gef.editpolicies.SelectionEditPolicy#showFocus()

	 */

	protected void showFocus() {

		focusRect = new AbstractHandle((GraphicalEditPart) getHost(),

				new Locator() {

					public void relocate(IFigure target) {

						IFigure figure = getHostFigure();

						Rectangle r;

						if (figure instanceof HandleBounds)

							r = ((HandleBounds) figure).getHandleBounds()

									.getCopy();

						else

							r = getHostFigure().getBounds().getResized(-1, -1);

						getHostFigure().translateToAbsolute(r);

						target.translateToRelative(r);

						target.setBounds(r.expand(5, 5).resize(1, 1));

					}

				}) {

			{

				setBorder(new FocusBorder());

			}

			protected DragTracker createDragTracker() {

				return null;

			}

		};

		addFeedback(focusRect);

	}

	/**

	 * Calls other methods as appropriate.

	 * 

	 * @see org.eclipse.gef.EditPolicy#showSourceFeedback(org.eclipse.gef.Request)

	 */

	public void showSourceFeedback(Request request) {

		if ((REQ_MOVE.equals(request.getType()) && isDragAllowed())

				|| REQ_ADD.equals(request.getType())

				|| REQ_CLONE.equals(request.getType()))

			showChangeBoundsFeedback((ChangeBoundsRequest) request);

	}

	/**

	 * Returns <code>true</code> for move, align, add, and orphan request types.

	 * This method is never called for some of these types, but they are

	 * included for possible future use.

	 * 

	 * @see org.eclipse.gef.EditPolicy#understandsRequest(org.eclipse.gef.Request)

	 */

	public boolean understandsRequest(Request request) {

		if (REQ_MOVE.equals(request.getType()))

			return isDragAllowed();

		else if (REQ_CLONE.equals(request.getType())

				|| REQ_ADD.equals(request.getType())

				|| REQ_ORPHAN.equals(request.getType())

				|| REQ_ALIGN.equals(request.getType()))

			return true;

		return super.understandsRequest(request);

	}

}