DefaultChainedCodeAssistProcessor.java

/*******************************************************************************
 * Copyright (c) 2012-2017 Codenvy, S.A.
 * 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:
 *   Codenvy, S.A. - initial API and implementation
 *******************************************************************************/
package org.eclipse.che.ide.api.editor.codeassist;

import org.eclipse.che.ide.api.editor.texteditor.TextEditor;

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

/**
 * Allows to chain code assist processor for the default given content type. It will delegate to sub processors.
 * 
 * @author Florent Benoit
 */
public abstract class DefaultChainedCodeAssistProcessor implements CodeAssistProcessor {

    /** Delegate code assist processors. */
    private Set<? extends CodeAssistProcessor> codeAssistProcessors;

    /**
     * Allow to set processors.
     * 
     * @param codeAssistProcessors the expected processors
     */
    protected void setProcessors(final Set<? extends CodeAssistProcessor> codeAssistProcessors) {
        this.codeAssistProcessors = codeAssistProcessors;
    }

    @Override
    public void computeCompletionProposals(final TextEditor textEditor, final int offset, final boolean triggered, final CodeAssistCallback callback) {
        if (!this.codeAssistProcessors.isEmpty()) {
            final List<CompletionProposal> proposalList = new ArrayList<>();
            final List<CodeAssistProcessor> expected = new ArrayList<>();
            for (final CodeAssistProcessor processor : this.codeAssistProcessors) {
                expected.add(processor);
                processor.computeCompletionProposals(textEditor, offset, triggered, new CodeAssistCallback() {
                    @Override
                    public void proposalComputed(final List<CompletionProposal> processorProposals) {
                        expected.remove(processor);
                        if (processorProposals == null || processorProposals.isEmpty()) {
                            return;
                        }
                        proposalList.addAll(processorProposals);

                        // all processors have computed their result
                        if (expected.isEmpty()) {
                            callback.proposalComputed(proposalList);
                        }
                    }
                });
            }
        }
    }

    @Override
    public String getErrorMessage() {
        String errorMessage = null;
        if (!this.codeAssistProcessors.isEmpty()) {
            for (final CodeAssistProcessor processor : this.codeAssistProcessors) {
                final String processorErrorMessage = processor.getErrorMessage();
                if (processorErrorMessage != null) {
                    if (errorMessage == null) {
                        errorMessage = processorErrorMessage;
                    } else {
                        errorMessage = errorMessage.concat(processorErrorMessage);
                    }
                }
            }
        }
        return errorMessage;
    }

    /**
     * Returns the injected processors.
     * @return injected processors
     */
    public Set<? extends CodeAssistProcessor> getProcessors() {
        return this.codeAssistProcessors;
    }
}