org.eclipse.xtext.ui.editor.templates.DefaultTemplateProposalProvider.java Source code

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Here is the source code for org.eclipse.xtext.ui.editor.templates.DefaultTemplateProposalProvider.java

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/*******************************************************************************
 * Copyright (c) 2009 itemis AG (http://www.itemis.eu) 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
 *******************************************************************************/
package org.eclipse.xtext.ui.editor.templates;

import java.util.Collection;
import java.util.List;
import java.util.Set;

import org.eclipse.emf.ecore.EObject;
import org.eclipse.jface.resource.ImageDescriptor;
import org.eclipse.jface.text.templates.ContextTypeRegistry;
import org.eclipse.jface.text.templates.Template;
import org.eclipse.jface.text.templates.TemplateContext;
import org.eclipse.jface.text.templates.TemplateContextType;
import org.eclipse.jface.text.templates.persistence.TemplateStore;
import org.eclipse.swt.graphics.Image;
import org.eclipse.xtext.AbstractElement;
import org.eclipse.xtext.Assignment;
import org.eclipse.xtext.Keyword;
import org.eclipse.xtext.ParserRule;
import org.eclipse.xtext.RuleCall;
import org.eclipse.xtext.ui.editor.contentassist.ContentAssistContext;
import org.eclipse.xtext.ui.editor.contentassist.IFollowElementAcceptor;
import org.eclipse.xtext.ui.editor.contentassist.ITemplateAcceptor;
import org.eclipse.xtext.ui.internal.Activator;
import org.eclipse.xtext.util.XtextSwitch;

import com.google.common.collect.Sets;
import com.google.inject.Inject;
import com.google.inject.Singleton;

/**
 * @author Sebastian Zarnekow - Initial contribution and API
 * @author Sven Efftinge
 */
@Singleton
public class DefaultTemplateProposalProvider extends AbstractTemplateProposalProvider {

    private TemplateStore templateStore;
    private ContextTypeRegistry registry;
    private ContextTypeIdHelper helper;
    private Image image;

    @Inject
    public DefaultTemplateProposalProvider(TemplateStore templateStore, ContextTypeRegistry registry,
            ContextTypeIdHelper helper) {
        this.templateStore = templateStore;
        this.registry = registry;
        this.helper = helper;
    }

    @Override
    protected void createTemplates(TemplateContext templateContext, ContentAssistContext context,
            ITemplateAcceptor acceptor) {
        TemplateContextType contextType = templateContext.getContextType();
        Template[] templates = templateStore.getTemplates(contextType.getId());
        for (Template template : templates) {
            if (!acceptor.canAcceptMoreTemplates())
                return;
            if (validate(template, templateContext)) {
                acceptor.accept(createProposal(template, templateContext, context, getImage(template),
                        getRelevance(template)));
            }
        }
    }

    @Override
    protected TemplateContextType[] getContextTypes(final ContentAssistContext context) {
        final Set<TemplateContextType> result = Sets.newLinkedHashSet();
        IFollowElementAcceptor acceptor = createFollowElementAcceptor(result);
        List<AbstractElement> grammarElements = context.getFirstSetGrammarElements();
        for (AbstractElement element : grammarElements)
            acceptor.accept(element);
        return result.toArray(new TemplateContextType[result.size()]);
    }

    protected IFollowElementAcceptor createFollowElementAcceptor(final Collection<TemplateContextType> result) {
        return new FollowElementAcceptor(result);
    }

    public Image getImage(Template template) {
        if (image == null) {
            ImageDescriptor imageDescriptor = Activator.getImageDescriptor("icons/defaultoutlinenode.gif"); //$NON-NLS-1$
            image = imageDescriptor.createImage();
        }
        return image;
    }

    public int getRelevance(Template template) {
        return 90;
    }

    public class FollowElementAcceptor extends XtextSwitch<Boolean> implements IFollowElementAcceptor {

        private final Collection<TemplateContextType> result;

        public FollowElementAcceptor(Collection<TemplateContextType> result) {
            this.result = result;
        }

        @Override
        public Boolean defaultCase(EObject object) {
            return Boolean.TRUE;
        }

        @Override
        public Boolean caseKeyword(Keyword object) {
            addContextType(object);
            return Boolean.TRUE;
        }

        @Override
        public Boolean caseRuleCall(RuleCall object) {
            doSwitch(object.getRule());
            return Boolean.TRUE;
        }

        @Override
        public Boolean caseParserRule(ParserRule object) {
            addContextType(object);
            return Boolean.TRUE;
        }

        @Override
        public Boolean caseAssignment(Assignment object) {
            accept(object.getTerminal());
            return Boolean.TRUE;
        }

        @Override
        public void accept(AbstractElement element) {
            doSwitch(element);
        }

        protected void addContextType(ParserRule rule) {
            addContextType(helper.getId(rule));
        }

        protected void addContextType(Keyword keyword) {
            addContextType(helper.getId(keyword));
        }

        protected void addContextType(String id) {
            TemplateContextType contextType = registry.getContextType(id);
            if (contextType != null)
                result.add(contextType);
        }
    }

}