plugins/org.eclipse.dltk.javascript.ui/src/org/eclipse/dltk/javascript/internal/ui/text/completion/JavaScriptTypeCompletionProposalComputer.java

/*******************************************************************************
 * Copyright (c) 2005, 2007 IBM Corporation and others.
 * This program and the accompanying materials are made available under the
 * terms of the Eclipse Public License v. 2.0 which is available at
 * http://www.eclipse.org/legal/epl-2.0.
 * 
 * SPDX-License-Identifier: EPL-2.0
 *
 
 *******************************************************************************/
package org.eclipse.dltk.javascript.internal.ui.text.completion;

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

import org.eclipse.core.runtime.IProgressMonitor;
import org.eclipse.dltk.core.DLTKCore;
import org.eclipse.dltk.javascript.internal.ui.text.Symbols;
import org.eclipse.dltk.javascript.scriptdoc.JavaHeuristicScanner;
import org.eclipse.dltk.ui.text.completion.ContentAssistInvocationContext;
import org.eclipse.dltk.ui.text.completion.IScriptCompletionProposalExtension2;
import org.eclipse.dltk.ui.text.completion.ScriptCompletionProposalCollector;
import org.eclipse.dltk.ui.text.completion.ScriptCompletionProposalComputer;
import org.eclipse.dltk.ui.text.completion.ScriptContentAssistInvocationContext;
import org.eclipse.jface.text.IDocument;
import org.eclipse.jface.text.contentassist.ICompletionProposal;
import org.eclipse.jface.text.contentassist.IContextInformation;
import org.eclipse.jface.text.templates.TemplateCompletionProcessor;

public class JavaScriptTypeCompletionProposalComputer extends
		ScriptCompletionProposalComputer {

	@Override
	protected TemplateCompletionProcessor createTemplateProposalComputer(
			ScriptContentAssistInvocationContext context) {
		return null;
	}

	@Override
	protected int guessContextInformationPosition(
			ContentAssistInvocationContext context) {
		final int contextPosition = context.getInvocationOffset();
		IDocument document = context.getDocument();
		JavaHeuristicScanner scanner = new JavaHeuristicScanner(document);
		int bound = Math.max(-1, contextPosition - 200);
		// try the innermost scope of parentheses that looks like a method call
		int pos = contextPosition - 1;
		do {
			int paren = scanner.findOpeningPeer(pos, bound, '(', ')');
			if (paren == JavaHeuristicScanner.NOT_FOUND)
				break;
			int token = scanner.previousToken(paren - 1, bound);
			// next token must be a method name (identifier)
			if (token == Symbols.TokenIDENT)
				return paren;
			pos = paren - 1;
		} while (true);
		return contextPosition;
	}

	@Override
	public List<IContextInformation> computeContextInformation(
			ContentAssistInvocationContext context, IProgressMonitor monitor) {
		if (DLTKCore.DEBUG) {
			System.out.println("Offset: " + context.getInvocationOffset());
			System.out.println(getClass().getSimpleName()
					+ ".computeContextInformation()");
		}
		if (context instanceof ScriptContentAssistInvocationContext) {
			final int completionOffset = guessContextInformationPosition(context);
			final List<ICompletionProposal> proposals = computeScriptCompletionProposals(
					completionOffset,
					(ScriptContentAssistInvocationContext) context, monitor);
			if (DLTKCore.DEBUG) {
				System.out.println("!!! Proposals: " + proposals.size());
			}
			final List<IContextInformation> list = new ArrayList<IContextInformation>();
			for (ICompletionProposal proposal : proposals) {
				final IContextInformation contextInformation = proposal
						.getContextInformation();
				if (contextInformation == null) {
					continue;
				}
				if (proposal instanceof IScriptCompletionProposalExtension2) {
					final IScriptCompletionProposalExtension2 e2 = (IScriptCompletionProposalExtension2) proposal;
					if (e2.getReplacementLength() != e2.getName().length()) {
						continue;
					}
				}
				if (DLTKCore.DEBUG) {
					System.out.println("Proposal: " + proposal + ", info: "
							+ contextInformation.getInformationDisplayString());
				}
				list.add(contextInformation);
			}
			return list;
		}
		return Collections.emptyList();
	}

	@Override
	protected ScriptCompletionProposalCollector createCollector(
			ScriptContentAssistInvocationContext context) {
		return new JavaScriptCompletionProposalCollector(
				context.getSourceModule());
	}

}