org.eclipse.viatra2.visualisation/src/org/eclipse/viatra2/visualisation/common/labelproviders/HighlightableSmartLabelProvider.java

/*******************************************************************************
 * Copyright (c) 2010 Zoltan Ujhelyi and Istvan Rath and Daniel Varro.
 * 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:
 *    Istvan Rath - initial API and implementation
 *******************************************************************************/
package org.eclipse.viatra2.visualisation.common.labelproviders;

import java.lang.ref.WeakReference;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Map;
import java.util.TreeMap;

import org.eclipse.jface.resource.ColorRegistry;
import org.eclipse.swt.graphics.Color;
import org.eclipse.swt.graphics.RGB;
import org.eclipse.viatra2.core.IModelElement;
import org.eclipse.viatra2.core.IModelSpace;

/**
 * "Smart" label provider that displays useful labels.
 * This variant supports highlighting of certain elements.
 * @author istvan rath
 *
 */
public class HighlightableSmartLabelProvider extends SmartLabelProvider {

	/**
	 * FQN -> Set<Weakref<IModelElement> map to hold
	 * weak refs to model element from multiple model spaces.
	 */
	private static Map<String, Collection<WeakReference<IModelElement>>> highlightedElements =
		new TreeMap<String, Collection<WeakReference<IModelElement>>>();
	
	private static Map<String, Color> highlightColor =
		new TreeMap<String, Color>();
	
	/**
	 * Add an element to the set of highlighted elements.
	 * @param me the model element to highlight
	 */
	public static void highlightElement(IModelElement me) {
		highlightElement(me, null);
	}
	
	/**
	 * Highlights an element with a selected color string. Color strings could
	 * be instantiated using
	 * {@link HighlightableSmartLabelProvider#registerColor(int, int, int)}.
	 * @param me
	 *            the model element to highlight
	 * @param colorKey
	 *            the color key to use
	 */
	public static void highlightElement(IModelElement me, String colorKey) {
		String key = getKey(me);
		Collection<WeakReference<IModelElement>> set = 
			highlightedElements.get(key);
		if (set==null) {
			set = new ArrayList<WeakReference<IModelElement>>();
			highlightedElements.put(key, set);
		}
		set.add(new WeakReference<IModelElement>(me));
		if (colorKey!=null && hlCReg.get(colorKey)!=null){
			highlightColor.put(key, hlCReg.get(colorKey));
		}
	}
	/**
	 * Clears all the highlights from a given modelspace.
	 * @param msp
	 */
	public static void clearHighlights(IModelSpace msp){
		for (Collection<WeakReference<IModelElement>> c :highlightedElements.values()) {
			Collection<WeakReference<IModelElement>> toRemove = 
				new ArrayList<WeakReference<IModelElement>>();
			for (WeakReference<IModelElement> wr : c) {
				if (wr.get().getModelSpace().equals(msp)) {
					toRemove.add(wr);
				}
			}
			c.removeAll(toRemove);
		}
	}
	
	private static String getKey(IModelElement me) {
		return me.getID();
	}
	
	/**
	 * Remove an element from the set of highlighted ones.
	 * @param me 
	 */
	public static void unhighlightElement(IModelElement me) {
		String key = getKey(me);
		Collection<WeakReference<IModelElement>> set = 
			highlightedElements.get(key);
		if (set!=null) {
			WeakReference<IModelElement> toRemove = null;
			for (WeakReference<IModelElement> target : set) {
				if (Equals(target.get(), me)) {					
					toRemove = target;
					break;
				}
			}
			if (toRemove!=null) {
				set.remove(toRemove);
			}
		}
		highlightColor.remove(key);
	}
	
	private static boolean Equals(IModelElement me0, IModelElement me1) {
		return me0.equals(me1) && me0.getModelSpace().equals(me1.getModelSpace());
	}
	
	public static boolean isHighlighted(IModelElement me) {
		String key = getKey(me);
		Collection<WeakReference<IModelElement>> set = 
			highlightedElements.get(key);
		if (set!=null) {
			for (WeakReference<IModelElement> target : set) {
				if (Equals(target.get(), me)) {
					return true;
				}
			}
		}
		return false;
	}
	
	/**
	 * Color registry for storing highlight colors.
	 */
	private static ColorRegistry hlCReg = new ColorRegistry();
	
	private Color HL;
	private static final int highlightwidth = 3;
	
	
	public static String registerColor(int r, int g, int b) {
		RGB rgb = new RGB(r,g,b);
		if (hlCReg.get(rgb.toString())==null) {
			hlCReg.put(rgb.toString(), rgb);
		}
		return rgb.toString();
	}
	
	public HighlightableSmartLabelProvider() {
		hlCReg.put("highlight", new RGB(255, 0, 0));
		HL = hlCReg.get("highlight");
	}
	
	@Override
	public int getBorderWidth(Object entity) {
		// if an entity is highlighted -> increase border width
		if (entity instanceof IModelElement && isHighlighted((IModelElement)entity)) {
			return highlightwidth;
		}
		return super.getBorderWidth(entity);
	}
	
	@Override
	public Color getBorderColor(Object entity) {
		Color c = _getColor(entity);
		return c!=null?c:super.getBorderColor(entity);
	}
	
	@Override
	public Color getBackgroundColour(Object entity) {
		Color c = _getColor(entity);
		return c!=null?c:super.getBackgroundColour(entity);
	}
	
	@Override
	public int getLineWidth(Object rel) {
		// if a relation is highlighted -> increase width
		if (rel instanceof IModelElement && isHighlighted((IModelElement)rel)) {
			return highlightwidth;
		}
		return super.getLineWidth(rel);
	}
	
	 @Override
	public Color getColor(Object entity) {
		Color c = _getColor(entity);
		return c!=null?c:super.getColor(entity);
	}
	 
	 private Color _getColor(Object entity) {
		 if (entity instanceof IModelElement && isHighlighted((IModelElement)entity)) {
				Color c = highlightColor.get(getKey((IModelElement)entity));
				if (c!=null) {
					return c;
				}
				return HL;
		 }
		 return null;
	 }
}