PagesConnectionHandle.java

/*******************************************************************************
 * Copyright (c) 2007 Exadel, Inc. and Red Hat, Inc.
 * Distributed under license by Red Hat, Inc. All rights reserved.
 * This program is 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:
 *     Exadel, Inc. and Red Hat, Inc. - initial API and implementation
 ******************************************************************************/ 
package org.jboss.tools.seam.ui.pages.editor.edit;

import java.beans.PropertyChangeEvent;
import java.beans.PropertyChangeListener;

import org.eclipse.draw2d.Connection;
import org.eclipse.draw2d.ConnectionLocator;
import org.eclipse.draw2d.Cursors;
import org.eclipse.draw2d.geometry.Point;
import org.eclipse.gef.ConnectionEditPart;
import org.eclipse.gef.DragTracker;
import org.eclipse.gef.handles.SquareHandle;
import org.eclipse.gef.tools.ConnectionEndpointTracker;

/**
 * A handle used on a {@link Connection}.
 */
public class PagesConnectionHandle extends SquareHandle implements PropertyChangeListener {
	private boolean vertical = false;
	private int index;

	public PagesConnectionHandle(ConnectionEditPart owner, boolean vertical,
			int index) {
		this.vertical = vertical;
		this.index = index;
		if (vertical)
			setCursor(Cursors.SIZEN);
		else
			setCursor(Cursors.SIZEW);

		setOwner(owner);
		setLocator(new JSFMidpointLocator(getConnection(), index));
	}

	protected DragTracker createDragTracker() {
		ConnectionEndpointTracker tracker;
		tracker = new PagesConnectionDragTracker((ConnectionEditPart) getOwner(),
				vertical, index);
		return tracker;
	}

	/**
	 * Adds this as a {@link org.eclipse.draw2d.FigureListener} to the owner's
	 * {@link org.eclipse.draw2d.Figure}.
	 */
	public void addNotify() {
		super.addNotify();
		getConnection().addPropertyChangeListener(Connection.PROPERTY_POINTS,
				this);
	}

	/**
	 * Returns the Connection this handle is on.
	 */
	public Connection getConnection() {
		return (Connection) getOwnerFigure();
	}

	protected boolean isVertical() {
		return vertical;
	}

	public void propertyChange(PropertyChangeEvent evt) {
		if (evt.getPropertyName().equals(Connection.PROPERTY_POINTS))
			revalidate();
	}

	public void removeNotify() {
		getConnection().removePropertyChangeListener(
				Connection.PROPERTY_POINTS, this);
		super.removeNotify();
	}

	class JSFMidpointLocator extends ConnectionLocator {
		private int index;

		public JSFMidpointLocator(Connection c, int i) {
			super(c);
			index = i;
		}

		protected int getIndex() {
			return index;
		}

		protected Point getReferencePoint() {
			Connection conn = super.getConnection();
			if (getIndex() + 1 > conn.getPoints().size() - 2) {
				PagesConnectionHandle.this.setVisible(false);
				return new Point(0, 0);
			}
			Point p = Point.SINGLETON;
			Point p1 = conn.getPoints().getPoint(getIndex());
			Point p2 = conn.getPoints().getPoint(getIndex() + 1);
			conn.translateToAbsolute(p1);
			conn.translateToAbsolute(p2);
			p.x = (p2.x - p1.x) / 2 + p1.x;
			p.y = (p2.y - p1.y) / 2 + p1.y;
			return p;
		}
	}

}