DotArrowTypeProposalProvider.java

/*******************************************************************************
 * Copyright (c) 2016 itemis AG and others.
 * 
 * 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:
 *    Tamas Miklossy (itemis AG) - initial API and implementation (bug #498324)
 *******************************************************************************/
package org.eclipse.gef.dot.internal.ui.language.contentassist;

import org.eclipse.gef.dot.internal.language.arrowtype.ArrowShape;
import org.eclipse.gef.dot.internal.language.arrowtype.DeprecatedShape;
import org.eclipse.gef.dot.internal.language.arrowtype.PrimitiveShape;
import org.eclipse.jface.text.contentassist.ICompletionProposal;
import org.eclipse.jface.viewers.StyledString;
import org.eclipse.swt.graphics.Image;
import org.eclipse.xtext.ui.editor.contentassist.ContentAssistContext;

/**
 * See
 * https://www.eclipse.org/Xtext/documentation/304_ide_concepts.html#content-assist
 * on how to customize the content assistant.
 */
public class DotArrowTypeProposalProvider extends
		org.eclipse.gef.dot.internal.ui.language.contentassist.AbstractDotArrowTypeProposalProvider {

	@Override
	protected ICompletionProposal createCompletionProposal(String proposal,
			StyledString displayString, Image image, int priority,
			String prefix, ContentAssistContext context) {

		for (DeprecatedShape deprecatedShape : DeprecatedShape.VALUES) {
			if (deprecatedShape.toString().equals(proposal)) {
				// don't propose the deprecated shapes
				return null;
			}
		}

		// don't propose primitive shapes invalid for the already parsed
		// modifier(s)
		if (context.getCurrentModel() instanceof ArrowShape
				&& PrimitiveShape.get(proposal) != null) {
			ArrowShape arrowShape = (ArrowShape) context.getCurrentModel();
			// The open modifier is not allowed for the primitive shapes
			// 'crow', 'curve', 'icurve', 'none', 'tee' and 'vee', so do not
			// propose them if the open modifier already has been parsed.
			if (arrowShape.isOpen()) {
				switch (PrimitiveShape.get(proposal)) {
				case CROW:
				case CURVE:
				case ICURVE:
				case NONE:
				case TEE:
				case VEE:
					return null;
				}
			}

			// The side modifier is not allowed for the primitive shapes
			// 'dot' and 'none', so do not propose them if the side modifier
			// already has been parsed.
			if (arrowShape.getSide() != null) {
				switch (PrimitiveShape.get(proposal)) {
				case DOT:
				case NONE:
					return null;
				}
			}
		}

		return super.createCompletionProposal(proposal, displayString, image,
				priority, prefix, context);
	}
}