RoomProposalProvider.java

/*******************************************************************************
 * Copyright (c) 2010 protos software gmbh (http://www.protos.de).
 * 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:
 * 		Thomas Schuetz and Henrik Rentz-Reichert (initial contribution)
 * 
 *******************************************************************************/

package org.eclipse.etrice.core.ui.contentassist;

import org.eclipse.emf.ecore.EObject;
import org.eclipse.etrice.core.ui.contentassist.AbstractRoomProposalProvider;
import org.eclipse.etrice.core.validation.ValidationUtil;
import org.eclipse.jface.text.contentassist.ICompletionProposal;
import org.eclipse.jface.viewers.StyledString;
import org.eclipse.swt.graphics.Image;
import org.eclipse.xtext.resource.IEObjectDescription;
import org.eclipse.xtext.ui.editor.contentassist.ContentAssistContext;

import com.google.common.base.Function;

import org.eclipse.etrice.core.room.ActorClass;
import org.eclipse.etrice.core.room.ActorRef;
import org.eclipse.etrice.core.room.RoomPackage;
/**
 * see http://www.eclipse.org/Xtext/documentation/latest/xtext.html#contentAssist on how to customize content assistant
 */
public class RoomProposalProvider extends AbstractRoomProposalProvider {
	
	protected class FilteredProposalCreator implements Function<IEObjectDescription, ICompletionProposal> {
		private IProposalFilter filter;
		private final ContentAssistContext contentAssistContext;
		private final String ruleName;

		protected FilteredProposalCreator(IProposalFilter filter, ContentAssistContext contentAssistContext, String ruleName) {
			this.filter = filter;
			this.contentAssistContext = contentAssistContext;
			this.ruleName = ruleName;
		}

		public ICompletionProposal apply(IEObjectDescription candidate) {
			if (candidate == null)
				return null;
			ICompletionProposal result = null;
			String proposal = candidate.getName();
			if (ruleName != null)
				proposal = getValueConverter().toString(proposal, ruleName);
			EObject objectOrProxy = candidate.getEObjectOrProxy();
			
			// three new lines in code taken from org.eclipse.xtext.ui.editor.contentassist.AbstractJavaBasedContentProposalProvider.DefaultProposalCreator
			if (!objectOrProxy.eIsProxy() && filter!=null)
				if (!filter.accept(contentAssistContext, candidate))
					return null;
			
			StyledString displayString = getStyledDisplayString(objectOrProxy, candidate.getQualifiedName(), candidate.getName());
			Image image = getImage(objectOrProxy);
			result = createCompletionProposal(proposal, displayString, image, contentAssistContext);
			getPriorityHelper().adjustCrossReferencePriority(result, contentAssistContext.getPrefix());			
			return result;
		}

	}
	
	protected class ActorRefFilter implements IProposalFilter {

		@Override
		public boolean accept(ContentAssistContext context, IEObjectDescription candidate) {
			if (!(context.getCurrentModel() instanceof ActorRef))
				// unexpected call??
				return false;
			
			ActorRef ar = (ActorRef) context.getCurrentModel();
			if (!(ar.eContainer() instanceof ActorClass))
				// can not filter due to lack of information
				return true;
			
			ActorClass ac = (ActorClass) ar.eContainer();
			
			EObject objectOrProxy = candidate.getEObjectOrProxy();
			
			if (objectOrProxy instanceof ActorClass) {
				ActorClass referenced = (ActorClass) objectOrProxy;
				return !ValidationUtil.isReferencing(referenced, ac);
			}
			
			return false;
		}
		
	}
	
	protected Function<IEObjectDescription, ICompletionProposal> getProposalFactory(String ruleName, ContentAssistContext contentAssistContext) {
		if (contentAssistContext!=null && contentAssistContext.getCurrentModel().eClass()==RoomPackage.eINSTANCE.getActorRef())
			return new FilteredProposalCreator(new ActorRefFilter(), contentAssistContext, ruleName);
		
		// delegate to default
		return super.getProposalFactory(ruleName, contentAssistContext);
	}

//	public void completeActorRef_Type(EObject model, Assignment assignment, ContentAssistContext context, ICompletionProposalAcceptor acceptor) {
//		super.completeActorRef_Type(
//			    model, 
//			    assignment, 
//			    context, 
//			    acceptor);
//	}
}