org.eclipse.viatra2.editor/src/org/eclipse/viatra2/treeeditor/providers/ViatraContentProvider.java

/*******************************************************************************
 * Copyright (c) 2004-2008 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.treeeditor.providers;

import java.util.Collection;

import org.eclipse.jface.viewers.ITreeContentProvider;
import org.eclipse.jface.viewers.TreeViewer;
import org.eclipse.jface.viewers.Viewer;
import org.eclipse.viatra2.core.IEntity;
import org.eclipse.viatra2.core.IModelElement;
import org.eclipse.viatra2.core.IRelation;
import org.eclipse.viatra2.treeeditor.ViatraTreeEditor;

public class ViatraContentProvider implements ITreeContentProvider {

	private ViatraTreeviewNotificationHandler iNotificationHandler;

	private ViatraTreeEditor iVTE;

	private ViatraRootProvider iVRP;

	public ViatraContentProvider(TreeViewer tv, ViatraTreeEditor vte) {
		iVTE = vte;
		iNotificationHandler = new ViatraTreeviewNotificationHandler(tv, this);
		iVTE.getFramework().getTopmodel().getNotificationManager().addAllListener(iNotificationHandler);
	}

	public void setDirty() {
		iVTE.setDirty();
	}

	/*
	 * This function should always receive root entities.
	 */
	public Object[] getElements(Object inputElement) {
		//System.out.println("CP: getElements called for "+inputElement.toString());
		if (inputElement instanceof IModelElement || inputElement instanceof ViatraRootProvider)
			return getChildren(inputElement);
		else
			return null;
	}

	public void dispose()
	{
		iVTE.getFramework().getTopmodel().getNotificationManager().removeAllListener(iNotificationHandler);
	}

	public void inputChanged(Viewer viewer, Object oldInput, Object newInput) {
		if (newInput instanceof ViatraRootProvider)
			iVRP = (ViatraRootProvider) newInput;
		// empty for the moment
	}

	public class TargetRelationDummy
	{
		public IRelation rel;
		public TargetRelationDummy(IRelation r) {
			this.rel = r;
		}
	}

	public Object[] getChildren(Object parentElement) {
		// Special case: dummy root element for the content provider to show root
		if (parentElement instanceof ViatraRootProvider)
		{
			IEntity ent = ((ViatraRootProvider) parentElement).getRootEntity();
			// addNotificationHandler(ent);
			return new Object[] { ent };
		}

		// register NH if not registered yet
		// addNotificationHandler((IModelElement)parentElement);
		Collection children = ((IModelElement)parentElement).getElementsInNamespace();

		String showTargets = iVTE.getFramework().getProperties().getRuntimeProperty(ViatraEditorPropertyProvider.VIATRA_EDITOR_PROVIDER_ID, ViatraEditorPropertyProvider.PROP_FORMATSTRING_RELATION_TARGET_SHOW);
		if ("true".equalsIgnoreCase(showTargets))
		{
			for (IRelation r : ((IModelElement)parentElement).getRelationsTo() )
			{
				children.add(new TargetRelationDummy(r));
			}
		}
		return children.toArray();
	}

	public Object getParent(Object element) {
		if (element instanceof IEntity)
			if (((IEntity) element).getParent() == null)
				return iVRP;
			else
				return ((IEntity)element).getParent();
		else if (element instanceof IRelation)
			return ((IRelation)element).getFrom();
		else if (element instanceof TargetRelationDummy)
			return ((TargetRelationDummy)element).rel.getTo();

		return null;
	}

	public boolean hasChildren(Object element) {
		//System.out.println("CP: hasChildren called for "+element.toString());
		if (element instanceof ViatraRootProvider)
			return true;

		if (element instanceof IModelElement && !((IModelElement)element).getElementsInNamespace().isEmpty())
			return true;

		String showTargets = iVTE.getFramework().getProperties().getRuntimeProperty(ViatraEditorPropertyProvider.VIATRA_EDITOR_PROVIDER_ID, ViatraEditorPropertyProvider.PROP_FORMATSTRING_RELATION_TARGET_SHOW);
		if ("true".equalsIgnoreCase(showTargets))
		{
			if (element instanceof IModelElement && !((IModelElement)element).getRelationsTo().isEmpty())
				return true;
		}
		return false;
	}

	protected void addNotificationHandler(IModelElement me) {

		if (!(me.getModelSpace()
				.getNotificationManager()
				.getNotificationListeners(me).contains(iNotificationHandler))) {

			// System.out.println("NH: registered for "+me.getFullyQualifiedName());
			me.getModelSpace()
				.getNotificationManager()
				.addNotificationListener(me,iNotificationHandler);
		}

	}

	protected void removeNotificationHandler(IModelElement me) {
		if ((me.getModelSpace()
				.getNotificationManager()
				.getNotificationListeners(me).contains(iNotificationHandler))) {

			// System.out.println("NH: deregistered for "+me.getFullyQualifiedName());
			me.getModelSpace()
				.getNotificationManager()
				.removeNotificationListener(me,iNotificationHandler);
		}
	}

}