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

 * Copyright 2005, CHISEL Group, University of Victoria, Victoria, BC, Canada.

 * 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: The Chisel Group, University of Victoria

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

package org.eclipse.zest.layouts.exampleStructures;

import java.util.HashMap;

import java.util.Map;

import org.eclipse.zest.layouts.LayoutBendPoint;

import org.eclipse.zest.layouts.LayoutEntity;

import org.eclipse.zest.layouts.LayoutRelationship;

import org.eclipse.zest.layouts.constraints.BasicEdgeConstraints;

import org.eclipse.zest.layouts.constraints.LabelLayoutConstraint;

import org.eclipse.zest.layouts.constraints.LayoutConstraint;

import org.eclipse.zest.layouts.dataStructures.BendPoint;

/**

 * The SimpleRelation class describes the relationship between

 * two objects: source and destination.  Each relationship

 * has a weight and direction associated with it.

 * Note: The source object is at the beginning of the relationship.

 * Note: The destination object is at the end of the relationship.

 *

 * @version  2.0

 * @author   Casey Best (version 1.0 by Jingwei Wu)

 * @author Chris Bennett

 */

public class SimpleRelationship implements LayoutRelationship {

	private static int DEFAULT_REL_LINE_WIDTH = 1;

	private static int DEFAULT_REL_LINE_WIDTH_SELECTED = DEFAULT_REL_LINE_WIDTH + 2;

	private static Object DEFAULT_RELATIONSHIP_COLOR;

	private static Object DEFAULT_RELATIONSHIP_HIGHLIGHT_COLOR;

	/** The line width for this relationship. */

	private int lineWidth = DEFAULT_REL_LINE_WIDTH;

	/** The color for this relationship. */

	private Object color = DEFAULT_RELATIONSHIP_COLOR;

	/**

	 * A list of layout dependent attributes

	 */

	private Map attributes;

	/**

	 * The sourceEntity of this SimpleRelation.

	 */

	protected LayoutEntity sourceEntity;

	/**

	 * The object of this SimpleRelation.

	 */

	protected LayoutEntity destinationEntity;

	/**

	 * If directional, algorithms must note the direction of the relationship.

	 * If not directional, algorithms are to ignore which direction the relationship is going.

	 * Switching the source and destination should make no difference. 

	 */

	protected boolean bidirectional;

	/**

	 * The weight given to this relation.

	 */

	private double weight;

	private Object internalRelationship;

	private LayoutBendPoint[] bendPoints;

	private String label;

	/**

	 * Constructor.

	 * @param sourceEntity The sourceEntity of this SimpleRelation.

	 * @param destinationEntity The object of this SimpleRelation.

	 * @param bidirectional Determines if the <code>sourceEntity</code> and

	 * <code>destinationEntity</code> are equal(exchangeable).

	 * @throws java.lang.NullPointerException If either <code>sourceEntity

	 * </code> or <code>destinationEntity</code> is <code>null</code>.

	 */

	public SimpleRelationship(LayoutEntity sourceEntity, LayoutEntity destinationEntity, boolean bidirectional) {

		this(sourceEntity, destinationEntity, bidirectional, 1);

	}

	/**

	 * Constructor.

	 * @param sourceEntity The sourceEntity of this SimpleRelation.

	 * @param destinationEntity The destinationEntity of this SimpleRelation.

	 * @param exchangeable Determines if the <code>sourceEntity</code> and

	 * <code>destinationEntity</code> are equal(exchangeable).

	 * @throws java.lang.NullPointerException If either <code>sourceEntity

	 * </code> or <code>destinationEntity</code> is <code>null</code>.

	 */

	public SimpleRelationship(LayoutEntity sourceEntity, LayoutEntity destinationEntity, boolean bidirectional, double weight) {

		this.destinationEntity = destinationEntity;

		this.sourceEntity = sourceEntity;

		this.bidirectional = bidirectional;

		this.weight = weight;

		this.attributes = new HashMap();

		this.lineWidth = DEFAULT_REL_LINE_WIDTH;

		this.color = DEFAULT_RELATIONSHIP_COLOR;

	}

	/**

	 * Gets the sourceEntity of this SimpleRelation whether the relation is

	 * exchangeable or not.

	 * @return The sourceEntity.

	 */

	public LayoutEntity getSourceInLayout() {

		return sourceEntity;

	}

	/**

	 * Gets the destinationEntity of this SimpleRelation whether the relation is

	 * exchangeable or not.

	 * @return The destinationEntity of this SimpleRelation.

	 */

	public LayoutEntity getDestinationInLayout() {

		return destinationEntity;

	}

	/**

	 * If bidirectional, the direction of the relationship doesn't matter.  Switching the source and destination should make no difference.

	 * If not bidirectional, layout algorithms need to take into account the direction of the relationship.  The direction is based on the

	 * source and destination entities.

	 */

	public boolean isBidirectionalInLayout() {

		return bidirectional;

	}

	public void setWeightInLayout(double weight) {

		this.weight = weight;

	}

	public double getWeightInLayout() {

		return weight;

	}

	/**

	 * An algorithm may require a place to store information.  Use this structure for that purpose.

	 */

	public void setAttributeInLayout(String attribute, Object value) {

		attributes.put(attribute, value);

	}

	/**

	 * An algorithm may require a place to store information.  Use this structure for that purpose.

	 */

	public Object getAttributeInLayout(String attribute) {

		return attributes.get(attribute);

	}

	public String toString() {

		String arrow = (isBidirectionalInLayout() ? " <-> " : " -> ");

		return "(" + sourceEntity + arrow + destinationEntity + ")";

	}

	public int getLineWidth() {

		return this.lineWidth;

	}

	public void setLineWidth(int lineWidth) {

		this.lineWidth = lineWidth;

	}

	public void resetLineWidth() {

		this.lineWidth = DEFAULT_REL_LINE_WIDTH;

	}

	public static void setDefaultSize(int i) {

		DEFAULT_REL_LINE_WIDTH = i;

		DEFAULT_REL_LINE_WIDTH_SELECTED = DEFAULT_REL_LINE_WIDTH + 2;

	}

	public void setSelected() {

		this.color = DEFAULT_RELATIONSHIP_HIGHLIGHT_COLOR;

		this.lineWidth = DEFAULT_REL_LINE_WIDTH_SELECTED;

	}

	public void setUnSelected() {

		this.color = DEFAULT_RELATIONSHIP_COLOR;

		this.lineWidth = DEFAULT_REL_LINE_WIDTH;

	}

	public Object getColor() {

		return color;

	}

	public void setColor(Object c) {

		this.color = c;

	}

	public static void setDefaultColor(Object c) {

		DEFAULT_RELATIONSHIP_COLOR = c;

	}

	public static void setDefaultHighlightColor(Object c) {

		DEFAULT_RELATIONSHIP_HIGHLIGHT_COLOR = c;

	}

	/* (non-Javadoc)

	 * @see ca.uvic.cs.chisel.layouts.LayoutRelationship#getInternalRelationship()

	 */

	public Object getLayoutInformation() {

		return internalRelationship;

	}

	/* (non-Javadoc)

	 * @see ca.uvic.cs.chisel.layouts.LayoutRelationship#setInternalRelationship(java.lang.Object)

	 */

	public void setLayoutInformation(Object layoutInformation) {

		this.internalRelationship = layoutInformation;

	}

	public void setBendPoints(LayoutBendPoint[] bendPoints) {

		this.bendPoints = bendPoints;

	}

	public LayoutBendPoint[] getBendPoints() {

		return this.bendPoints;

	}

	public void clearBendPoints() {

		this.bendPoints = new BendPoint[0];

	}

	public void setDestinationInLayout(LayoutEntity destination) {

		this.destinationEntity = destination;

	}

	/**

	 * Set the label for this edge (available in the label layout constraint). 

	 */

	public void setLabel(String label) {

		this.label = label;

	}

	/**

	 * Populate the specified layout constraint

	 */

	public void populateLayoutConstraint(LayoutConstraint constraint) {

		if (constraint instanceof LabelLayoutConstraint) {

			LabelLayoutConstraint labelConstraint = (LabelLayoutConstraint) constraint;

			labelConstraint.label = this.label;

			labelConstraint.pointSize = 18;

		} else if (constraint instanceof BasicEdgeConstraints) {

			// noop

		}

	}

	public Object getGraphData() {

		return null;

	}

	public void setGraphData(Object o) {

	}

}