org.eclipse.fmc.blockdiagram.editor/src/org/eclipse/fmc/blockdiagram/editor/features/add/CommunicationChannelAddFeature.java

/*******************************************************************************
 * <copyright>
 *
 * Copyright (c) 2013, 2013 SAP AG.
 * 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:
 *    SAP AG - initial API, implementation and documentation
 *
 * </copyright>
 *
 *******************************************************************************/
package org.eclipse.fmc.blockdiagram.editor.features.add;

import org.eclipse.emf.ecore.EAttribute;
import org.eclipse.emf.ecore.EObject;
import org.eclipse.fmc.blockdiagram.editor.algorithm.connection.FMCConnectionAlgorithm;
import org.eclipse.fmc.blockdiagram.editor.algorithm.connection.FMCConnectionAlgorithmFactory;
import org.eclipse.fmc.blockdiagram.editor.model.ConnectionStyle;
import org.eclipse.fmc.blockdiagram.editor.model.FMCType;
import org.eclipse.fmc.blockdiagram.editor.model.FMCTypeChecker;
import org.eclipse.fmc.blockdiagram.editor.model.FMCTypeCheckerFactory;
import org.eclipse.fmc.blockdiagram.editor.util.StyleUtil;
import org.eclipse.fmc.mm.RequestDirection;
import org.eclipse.graphiti.features.IFeatureProvider;
import org.eclipse.graphiti.features.context.IAddConnectionContext;
import org.eclipse.graphiti.features.context.IAddContext;
import org.eclipse.graphiti.mm.algorithms.Polygon;
import org.eclipse.graphiti.mm.algorithms.Polyline;
import org.eclipse.graphiti.mm.algorithms.Text;
import org.eclipse.graphiti.mm.pictograms.Connection;
import org.eclipse.graphiti.mm.pictograms.ConnectionDecorator;
import org.eclipse.graphiti.mm.pictograms.Diagram;
import org.eclipse.graphiti.mm.pictograms.PictogramElement;
import org.eclipse.graphiti.services.Graphiti;
import org.eclipse.graphiti.services.IGaService;
import org.eclipse.graphiti.services.IPeService;

/**
 * This class is a specialization of the {@link ConnectionAddFeature} and
 * responsible for adding access via channels. Both bidirectional and
 * unidirectional as well as request response are supported.
 * 
 * @author Benjamin Schmeling
 * 
 */
public class CommunicationChannelAddFeature extends ConnectionAddFeature {

	private FMCTypeChecker checker = FMCTypeCheckerFactory.getInstance();
	private FMCConnectionAlgorithmFactory factory = FMCConnectionAlgorithmFactory
			.getInstance();
	/**
	 * The position of the decorator. It is not the center because manhattan
	 * connections tend to reroute at this position.
	 */
	private static final float decoPosX = 0.4f;
	/**
	 * The default channel text if not specified.
	 */
	protected static final String defaultChannelText = "Channel";

	/**
	 * 
	 * @param fp
	 *            The feature provider.
	 * @param type
	 *            The type of the connection.
	 */
	public CommunicationChannelAddFeature(IFeatureProvider fp,
			ConnectionStyle type) {
		super(fp, type);
	}

	@Override
	/*
	 * (non-Javadoc)
	 * 
	 * @see
	 * org.eclipse.graphiti.func.IAdd#canAdd(org.eclipse.graphiti.features.context
	 * .IAddContext)
	 */
	public boolean canAdd(IAddContext context) {
		return true;
	}

	@Override
	/*
	 * (non-Javadoc)
	 * 
	 * @see
	 * org.eclipse.graphiti.func.IAdd#add(org.eclipse.graphiti.features.context
	 * .IAddContext)
	 */
	public PictogramElement add(IAddContext context) {
		IPeService pe = Graphiti.getPeService();
		IGaService ga = Graphiti.getGaService();

		IAddConnectionContext cContext = (IAddConnectionContext) context;

		Connection cShape = super.createConnection();
		Polyline line = ga.createPolyline(cShape);
		cShape.setStart(cContext.getSourceAnchor());
		cShape.setEnd(cContext.getTargetAnchor());
		line.setForeground(manageColor(0, 0, 0));

		FMCConnectionAlgorithm connectionAlgorithm = factory.getAlgorithm(cShape);
		connectionAlgorithm.createChannelSymbol(cShape, getDiagram());

		if (checker.isUnidirectionalCommunicationChannel(context.getNewObject())) {
			createCenterArrow(getDiagram(), cShape, true);
			createArrowDecorator(getDiagram(), cShape, true);
		}
		if (checker.isReqRespCommunicationChannel((context.getNewObject()))) {
			connectionAlgorithm.setRequestDirection(cShape,
					RequestDirection.REQUEST, (getDiagram()));
		}
		linkModel(cShape, cContext);
		ConnectionDecorator textDecorator = pe.createConnectionDecorator(
				cShape, true, decoPosX, true);
		Text text = ga.createText(textDecorator);
		text.setForeground(manageColor(0, 0, 0));
		ga.setLocation(text, 0, 15);
		// set reference name in the text decorator

		text.setValue(getNameFromObject(context.getNewObject()));
		text.setStyle(StyleUtil.getStyle(getDiagram(), StyleUtil.CONNECTION));
		linkTextWithModel(textDecorator, context.getNewObject());
		return cShape;
	}

	protected void linkTextWithModel(PictogramElement element, Object obj) {
		if (obj instanceof FMCType)
			link(element, FMCType.Text);
		else {
			link(element, obj);
			Graphiti.getLinkService().setLinkProperty(element, "name");
		}
	}

	/**
	 * Returns the value of the name attribute of the object.
	 * 
	 * @param obj
	 *            The object to get the name from.
	 * 
	 * @return The value of the name attribute of the eobject, if not an eobject
	 *         return default text.
	 */
	protected String getNameFromObject(Object obj) {
		if (obj instanceof EObject) {
			String name = null;
			EObject eobj = ((EObject) obj);
			for (EAttribute attr : eobj.eClass().getEAllAttributes()) {
				if ("name".equals(attr.getName())) {
					name = (String) eobj.eGet(attr);
					if (name != null)
						return name;
					else {
						eobj.eSet(attr, defaultChannelText);
						return defaultChannelText;
					}
				}
			}
		}
		return defaultChannelText;
	}

	/**
	 * Creates the graphical representation of the arrow located near the
	 * channel oval decorator.
	 * 
	 * @param diagram
	 *            The diagram to create the arrow for.
	 * @param connection
	 *            The connection to be decorated with the arrow.
	 * @param defaultDirection
	 *            True if the default direction should be used (from source to
	 *            target), false otherwise.
	 */
	public static void createCenterArrow(Diagram diagram, Connection connection,
			boolean defaultDirection) {
		ConnectionDecorator arrow1 = Graphiti.getPeService()
				.createConnectionDecorator(connection, false, decoPosX, true);
		Polygon p1 = null;
		if (defaultDirection)
			p1 = Graphiti.getGaService().createPolygon(arrow1,
					new int[] { 23, -6, 8, 0, 23, 6, 20, 0 });
		else
			p1 = Graphiti.getGaService().createPolygon(arrow1,
					new int[] { -21, -6, -6, 0, -21, 6, -18, 0 });
		p1.setBackground(Graphiti.getGaService().manageColor(diagram, 0, 0, 0));
	}
	
	/**
	 * Links the domain model object from the context with the connection.
	 * 
	 * @param con
	 *            The connection to be linked with.
	 * @param context
	 *            The add context containing the domain object.
	 */
	protected void linkModel(Connection con, IAddContext context) {
		link(con, context.getNewObject());
	}

}