/*
* Copyright 2010 JBoss Inc
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.drools.eclipse.editors.completion;
import java.util.Collections;
import java.util.Iterator;
import java.util.List;
import org.eclipse.jface.text.BadLocationException;
import org.eclipse.jface.text.IDocument;
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 org.eclipse.ui.IEditorPart;
public abstract class AbstractCompletionProcessor implements IContentAssistProcessor {
private IEditorPart editor;
public AbstractCompletionProcessor(IEditorPart editor) {
this.editor = editor;
}
protected IEditorPart getEditor() {
return editor;
}
public ICompletionProposal[] computeCompletionProposals(ITextViewer viewer, int documentOffset) {
List<ICompletionProposal> proposals = getCompletionProposals(viewer, documentOffset);
if (proposals == null) {
return new ICompletionProposal[0];
}
Collections.sort(proposals, new RuleCompletionProposal.RuleCompletionProposalComparator());
return proposals.toArray(new ICompletionProposal[proposals.size()]);
}
/**
* Returns a list of RuleCompletionProposals.
*
* @param viewer
* @param documentOffset
* @return
*/
protected abstract List<ICompletionProposal> getCompletionProposals(ITextViewer viewer, int documentOffset);
/**
* Filter out the proposals whose content does not start with the given prefix.
*/
protected static void filterProposalsOnPrefix(String prefix, List<ICompletionProposal> props) {
if ( prefix != null && prefix.trim().length() > 0 ) {
Iterator<ICompletionProposal> iterator = props.iterator();
String prefixLc = prefix.toLowerCase();
while ( iterator.hasNext() ) {
ICompletionProposal item = iterator.next();
String content = item.getDisplayString().toLowerCase();
if ( !content.toLowerCase().startsWith( prefixLc ) ) {
iterator.remove();
}
}
}
}
/**
* Read some text from behind the cursor position.
* This provides context to both filter what is shown based
* on what the user has typed in, and also to provide more information for the
* list of suggestions based on context.
*/
protected String readBackwards(int documentOffset, IDocument doc) throws BadLocationException {
int startPart = doc.getPartition(documentOffset).getOffset();
String prefix = doc.get(startPart, documentOffset - startPart);
return prefix;
}
/*
* @see IContentAssistProcessor
*/
public char[] getCompletionProposalAutoActivationCharacters() {
return null;
}
/*
* @see IContentAssistProcessor
*/
public char[] getContextInformationAutoActivationCharacters() {
return null;
}
/*
* @see IContentAssistProcessor
*/
public IContextInformationValidator getContextInformationValidator() {
return null;
}
/*
* @see IContentAssistProcessor
*/
public IContextInformation[] computeContextInformation(ITextViewer viewer, int documentOffset) {
return null;
}
/*
* @see IContentAssistProcessor
*/
public String getErrorMessage() {
return null;
}
}