eu.esdihumboldt.hale.ui.util.groovy.internal.contentassist.GroovyASTCompletionProcessor.java Source code

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Here is the source code for eu.esdihumboldt.hale.ui.util.groovy.internal.contentassist.GroovyASTCompletionProcessor.java

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/*
 * Copyright (c) 2013 Data Harmonisation Panel
 * 
 * All rights reserved. This program and the accompanying materials are made
 * available under the terms of the GNU Lesser General Public License as
 * published by the Free Software Foundation, either version 3 of the License,
 * or (at your option) any later version.
 * 
 * You should have received a copy of the GNU Lesser General Public License
 * along with this distribution. If not, see <http://www.gnu.org/licenses/>.
 * 
 * Contributors:
 *     Data Harmonisation Panel <http://www.dhpanel.eu>
 */

package eu.esdihumboldt.hale.ui.util.groovy.internal.contentassist;

import java.util.ArrayList;
import java.util.List;

import org.eclipse.jface.text.ITextViewer;
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 com.google.common.collect.ImmutableList;
import com.google.common.collect.Iterables;

import de.fhg.igd.slf4jplus.ALogger;
import de.fhg.igd.slf4jplus.ALoggerFactory;
import eu.esdihumboldt.hale.ui.util.groovy.GroovyCompletionProposals;
import eu.esdihumboldt.hale.ui.util.groovy.ast.GroovyAST;
import eu.esdihumboldt.hale.ui.util.source.CompilingSourceViewer;

/**
 * Groovy AST based completion processor that delegates the actual computation
 * to {@link GroovyCompletionProposals}.
 * 
 * @author Simon Templer
 */
public class GroovyASTCompletionProcessor implements IContentAssistProcessor {

    private static final ALogger log = ALoggerFactory.getLogger(GroovyASTCompletionProcessor.class);

    private final List<? extends GroovyCompletionProposals> proposals;

    /**
     * Constructor.
     * 
     * @param proposals the Groovy completion proposal computers this object
     *            delegates to
     */
    public GroovyASTCompletionProcessor(Iterable<? extends GroovyCompletionProposals> proposals) {
        super();
        this.proposals = (proposals != null) ? (ImmutableList.copyOf(proposals)) : (null);
    }

    @Override
    public ICompletionProposal[] computeCompletionProposals(final ITextViewer viewer, final int offset) {
        if (proposals == null || proposals.isEmpty()) {
            return null;
        }

        if (viewer instanceof CompilingSourceViewer<?>) {

            CompilingSourceViewer<?> csv = (CompilingSourceViewer<?>) viewer;
            try {
                Object compiled = csv.getCompiled().get();
                if (compiled instanceof GroovyAST) {
                    // the Groovy AST
                    GroovyAST ast = (GroovyAST) compiled;
                    // the line (0-based)
                    int line = csv.getDocument().getLineOfOffset(offset);
                    // the line column (0-based)
                    int column = offset - csv.getDocument().getLineOffset(line);
                    // locations in Groovy AST are 1-based
                    line++;
                    column++;

                    List<ICompletionProposal> list = new ArrayList<>();

                    // add proposals of individual computers
                    for (GroovyCompletionProposals proposal : proposals) {
                        Iterable<? extends ICompletionProposal> computed = proposal.computeProposals(viewer, ast,
                                line, column, offset);
                        if (computed != null) {
                            Iterables.addAll(list, computed);
                        }
                    }

                    return list.toArray(new ICompletionProposal[list.size()]);
                }
            } catch (Exception e) {
                log.warn("Failed to get AST to compute completion proposals", e);
            }
        }

        return null;
    }

    @Override
    public IContextInformation[] computeContextInformation(ITextViewer viewer, int offset) {
        return null;
    }

    @Override
    public char[] getCompletionProposalAutoActivationCharacters() {
        return null;
    }

    @Override
    public char[] getContextInformationAutoActivationCharacters() {
        return null;
    }

    @Override
    public String getErrorMessage() {
        return null;
    }

    @Override
    public IContextInformationValidator getContextInformationValidator() {
        return null;
    }

}