/*******************************************************************************
 * 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.examples.logicdesigner.edit;

import java.beans.PropertyChangeEvent;
import java.beans.PropertyChangeListener;
import java.util.List;

import org.eclipse.draw2d.ConnectionAnchor;
import org.eclipse.draw2d.geometry.Dimension;
import org.eclipse.draw2d.geometry.Point;
import org.eclipse.draw2d.geometry.Rectangle;

import org.eclipse.gef.AccessibleEditPart;
import org.eclipse.gef.ConnectionEditPart;
import org.eclipse.gef.EditPart;
import org.eclipse.gef.EditPolicy;
import org.eclipse.gef.GraphicalEditPart;
import org.eclipse.gef.NodeEditPart;
import org.eclipse.gef.Request;
import org.eclipse.gef.requests.DropRequest;

import org.eclipse.gef.examples.logicdesigner.figures.NodeFigure;
import org.eclipse.gef.examples.logicdesigner.model.LogicSubpart;
import org.eclipse.gef.examples.logicdesigner.model.Wire;

/**
 * Porvides support for 
 */
abstract public class LogicEditPart
	extends org.eclipse.gef.editparts.AbstractGraphicalEditPart
	implements NodeEditPart, PropertyChangeListener
{

private AccessibleEditPart acc;

public void activate(){
	if (isActive())
		return;
	super.activate();
	getLogicSubpart().addPropertyChangeListener(this);
}

protected void createEditPolicies(){
	installEditPolicy(EditPolicy.COMPONENT_ROLE, new LogicElementEditPolicy());
	installEditPolicy(EditPolicy.GRAPHICAL_NODE_ROLE, new LogicNodeEditPolicy());
}

abstract protected AccessibleEditPart createAccessible();

/**
 * Makes the EditPart insensible to changes in the model
 * by removing itself from the model's list of listeners.
 */
public void deactivate(){
	if (!isActive())
		return;
	super.deactivate();
	getLogicSubpart().removePropertyChangeListener(this);
}

protected AccessibleEditPart getAccessibleEditPart() {
	if (acc == null)
		acc = createAccessible();
	return acc;
}

/**
 * Returns the model associated with this as a LogicSubPart.
 *
 * @return  The model of this as a LogicSubPart.
 */
protected LogicSubpart getLogicSubpart(){
	return (LogicSubpart)getModel();
}

/**
 * Returns a list of connections for which this is the 
 * source.
 *
 * @return List of connections.
 */
protected List getModelSourceConnections(){
	return getLogicSubpart().getSourceConnections();
}

/**
 * Returns a list of connections for which this is the 
 * target.
 *
 * @return  List of connections.
 */
protected List getModelTargetConnections(){
	return getLogicSubpart().getTargetConnections();
}

/** 
 * Returns the Figure of this, as a node type figure.
 *
 * @return  Figure as a NodeFigure.
 */
protected NodeFigure getNodeFigure(){
	return (NodeFigure) getFigure();
}

/**
 * Returns the connection anchor for the given
 * ConnectionEditPart's source. 
 *
 * @return  ConnectionAnchor.
 */
public ConnectionAnchor getSourceConnectionAnchor(ConnectionEditPart connEditPart) {
	Wire wire = (Wire) connEditPart.getModel();
	return getNodeFigure().getConnectionAnchor(wire.getSourceTerminal());
}

/**
 * Returns the connection anchor of a source connection which
 * is at the given point.
 * 
 * @return  ConnectionAnchor.
 */
public ConnectionAnchor getSourceConnectionAnchor(Request request) {
	Point pt = new Point(((DropRequest)request).getLocation());
	return getNodeFigure().getSourceConnectionAnchorAt(pt);
}

/**
 * Returns the connection anchor for the given 
 * ConnectionEditPart's target.
 *
 * @return  ConnectionAnchor.
 */
public ConnectionAnchor getTargetConnectionAnchor(ConnectionEditPart connEditPart) {
	Wire wire = (Wire) connEditPart.getModel();
	return getNodeFigure().getConnectionAnchor(wire.getTargetTerminal());
}

/**
 * Returns the connection anchor of a terget connection which
 * is at the given point.
 *
 * @return  ConnectionAnchor.
 */
public ConnectionAnchor getTargetConnectionAnchor(Request request) {
	Point pt = new Point(((DropRequest)request).getLocation());
	return getNodeFigure().getTargetConnectionAnchorAt(pt);
}

/**
 * Returns the name of the given connection anchor.
 *
 * @return  The name of the ConnectionAnchor as a String.
 */
final protected String mapConnectionAnchorToTerminal(ConnectionAnchor c){
	return getNodeFigure().getConnectionAnchorName(c);
}

/**
 * Handles changes in properties of this. It is 
 * activated through the PropertyChangeListener.
 * It updates children, source and target connections,
 * and the visuals of this based on the property
 * changed.
 *
 * @param evt  Event which details the property change.
 */
public void propertyChange(PropertyChangeEvent evt){
	String prop = evt.getPropertyName();
	if (LogicSubpart.CHILDREN.equals(prop)) {
		if (evt.getOldValue() instanceof Integer)
			// new child
			addChild(createChild(evt.getNewValue()), ((Integer)evt
					.getOldValue()).intValue());
		else
			// remove child
			removeChild((EditPart)getViewer().getEditPartRegistry().get(
					evt.getOldValue()));
	}
	else if (LogicSubpart.INPUTS.equals(prop))
		refreshTargetConnections();
	else if (LogicSubpart.OUTPUTS.equals(prop))
		refreshSourceConnections();
	else if (prop.equals(LogicSubpart.ID_SIZE) || prop.equals(LogicSubpart.ID_LOCATION))
		refreshVisuals();
}

/**
 * Updates the visual aspect of this. 
 */
protected void refreshVisuals() {
	Point loc = getLogicSubpart().getLocation();
	Dimension size= getLogicSubpart().getSize();
	Rectangle r = new Rectangle(loc ,size);

	((GraphicalEditPart) getParent()).setLayoutConstraint(
		this,
		getFigure(),
		r);
}

}