query/plugins/org.eclipse.acceleo.query.ide.ui/src/org/eclipse/acceleo/query/ide/ui/viewer/AQLCompletionProcessor.java

/*******************************************************************************
 * Copyright (c) 2017 Obeo.
 * 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:
 *     Obeo - initial API and implementation
 *******************************************************************************/
package org.eclipse.acceleo.query.ide.ui.viewer;

import java.util.List;
import java.util.Map;
import java.util.Set;

import org.eclipse.acceleo.query.runtime.ICompletionResult;
import org.eclipse.acceleo.query.runtime.IQueryCompletionEngine;
import org.eclipse.acceleo.query.runtime.IReadOnlyQueryEnvironment;
import org.eclipse.acceleo.query.runtime.impl.BasicFilter;
import org.eclipse.acceleo.query.runtime.impl.QueryCompletionEngine;
import org.eclipse.acceleo.query.validation.type.IType;
import org.eclipse.jface.text.ITextViewer;
import org.eclipse.jface.text.contentassist.ContextInformationValidator;
import org.eclipse.jface.text.contentassist.ICompletionProposal;
import org.eclipse.jface.text.contentassist.IContentAssistProcessor;
import org.eclipse.jface.text.contentassist.IContextInformation;
import org.eclipse.jface.text.contentassist.IContextInformationValidator;
import org.eclipse.jface.viewers.ILabelProvider;

/**
 * AQL {@link IContentAssistProcessor}.
 * 
 * @author <a href="mailto:yvan.lussaud@obeo.fr">Yvan Lussaud</a>
 */
public class AQLCompletionProcessor implements IContentAssistProcessor {

	/**
	 * The {@link ILabelProvider}.
	 */
	private ILabelProvider labelProvider;

	/**
	 * The {@link IQueryCompletionEngine}.
	 */
	private final IQueryCompletionEngine engine;

	/**
	 * The set of defined variables types.
	 */
	private final Map<String, Set<IType>> variableTypes;

	/**
	 * Constructor.
	 * 
	 * @param labelProvider
	 *            the {@link ILabelProvider}
	 * @param queryEnvironment
	 *            the {@link IReadOnlyQueryEnvironment}
	 * @param variableTypes
	 *            the set of defined variables types
	 */
	public AQLCompletionProcessor(ILabelProvider labelProvider, IReadOnlyQueryEnvironment queryEnvironment,
			Map<String, Set<IType>> variableTypes) {
		this.labelProvider = labelProvider;
		engine = new QueryCompletionEngine(queryEnvironment);
		this.variableTypes = variableTypes;
	}

	/**
	 * {@inheritDoc}
	 *
	 * @see org.eclipse.jface.text.contentassist.IContentAssistProcessor#computeCompletionProposals(org.eclipse.jface.text.ITextViewer,
	 *      int)
	 */
	public ICompletionProposal[] computeCompletionProposals(ITextViewer viewer, int offset) {
		final ICompletionResult completionResult = engine.getCompletion(viewer.getDocument().get(), offset,
				variableTypes);
		List<org.eclipse.acceleo.query.runtime.ICompletionProposal> proposals = completionResult.getProposals(
				new BasicFilter(completionResult));

		final ICompletionProposal[] result = new ICompletionProposal[proposals.size()];
		int i = 0;
		for (org.eclipse.acceleo.query.runtime.ICompletionProposal proposal : proposals) {
			result[i++] = new AQLCompletionProposal(labelProvider, completionResult, proposal);
		}

		return result;
	}

	/**
	 * {@inheritDoc}
	 *
	 * @see org.eclipse.jface.text.contentassist.IContentAssistProcessor#computeContextInformation(org.eclipse.jface.text.ITextViewer,
	 *      int)
	 */
	public IContextInformation[] computeContextInformation(ITextViewer viewer, int offset) {
		return new IContextInformation[] {};
	}

	/**
	 * {@inheritDoc}
	 *
	 * @see org.eclipse.jface.text.contentassist.IContentAssistProcessor#getCompletionProposalAutoActivationCharacters()
	 */
	public char[] getCompletionProposalAutoActivationCharacters() {
		return new char[] {'.', '>', ' ', };
	}

	/**
	 * {@inheritDoc}
	 *
	 * @see org.eclipse.jface.text.contentassist.IContentAssistProcessor#getContextInformationAutoActivationCharacters()
	 */
	public char[] getContextInformationAutoActivationCharacters() {
		return new char[] {'.', '>', ' ', };
	}

	/**
	 * {@inheritDoc}
	 *
	 * @see org.eclipse.jface.text.contentassist.IContentAssistProcessor#getErrorMessage()
	 */
	public String getErrorMessage() {
		return null;
	}

	/**
	 * {@inheritDoc}
	 *
	 * @see org.eclipse.jface.text.contentassist.IContentAssistProcessor#getContextInformationValidator()
	 */
	public IContextInformationValidator getContextInformationValidator() {
		return new ContextInformationValidator(this);
	}

}