/*******************************************************************************
* Copyright (c) 2000, 2008 IBM Corporation 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
*
* Contributors:
* IBM Corporation - initial API and implementation
*******************************************************************************/
package org.eclipse.wst.jsdt.internal.ui.text.template.contentassist;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.Iterator;
import java.util.Map;
import java.util.Map.Entry;
import org.eclipse.core.runtime.Assert;
import org.eclipse.jface.text.BadLocationException;
import org.eclipse.jface.text.IDocument;
import org.eclipse.jface.text.IRegion;
import org.eclipse.jface.text.ITextViewer;
import org.eclipse.jface.text.Position;
import org.eclipse.jface.text.Region;
import org.eclipse.jface.text.templates.GlobalTemplateVariables;
import org.eclipse.jface.text.templates.Template;
import org.eclipse.jface.text.templates.TemplateContextType;
import org.eclipse.swt.graphics.Point;
import org.eclipse.wst.jsdt.core.IJavaScriptUnit;
import org.eclipse.wst.jsdt.internal.corext.template.java.CompilationUnitContext;
import org.eclipse.wst.jsdt.internal.corext.template.java.CompilationUnitContextType;
import org.eclipse.wst.jsdt.internal.ui.JavaScriptPlugin;
import org.eclipse.wst.jsdt.internal.ui.JavaPluginImages;
public class TemplateEngine {
private static final String $_LINE_SELECTION= "${" + GlobalTemplateVariables.LineSelection.NAME + "}"; //$NON-NLS-1$ //$NON-NLS-2$
private static final String $_WORD_SELECTION= "${" + GlobalTemplateVariables.WordSelection.NAME + "}"; //$NON-NLS-1$ //$NON-NLS-2$
/** The context type. */
private TemplateContextType fContextType;
/** The result proposals. */
private ArrayList fProposals= new ArrayList();
/** Positions created on the key documents to remove in reset. */
private final Map fPositions= new HashMap();
/**
* Creates the template engine for a particular context type.
* See <code>TemplateContext</code> for supported context types.
*/
public TemplateEngine(TemplateContextType contextType) {
Assert.isNotNull(contextType);
fContextType= contextType;
}
/**
* Empties the collector.
*/
public void reset() {
fProposals.clear();
for (Iterator it= fPositions.entrySet().iterator(); it.hasNext();) {
Entry entry= (Entry) it.next();
IDocument doc= (IDocument) entry.getKey();
Position position= (Position) entry.getValue();
doc.removePosition(position);
}
fPositions.clear();
}
/**
* Returns the array of matching templates.
*/
public TemplateProposal[] getResults() {
return (TemplateProposal[]) fProposals.toArray(new TemplateProposal[fProposals.size()]);
}
/**
* Inspects the context of the compilation unit around <code>completionPosition</code>
* and feeds the collector with proposals.
* @param viewer the text viewer
* @param completionPosition the context position in the document of the text viewer
* @param compilationUnit the compilation unit (may be <code>null</code>)
*/
public void complete(ITextViewer viewer, int completionPosition, IJavaScriptUnit compilationUnit) {
IDocument document= viewer.getDocument();
if (!(fContextType instanceof CompilationUnitContextType))
return;
Point selection= viewer.getSelectedRange();
Position position= new Position(completionPosition, selection.y);
// remember selected text
String selectedText= null;
if (selection.y != 0) {
try {
selectedText= document.get(selection.x, selection.y);
document.addPosition(position);
fPositions.put(document, position);
} catch (BadLocationException e) {}
}
CompilationUnitContext context= ((CompilationUnitContextType) fContextType).createContext(document, position, compilationUnit);
context.setVariable("selection", selectedText); //$NON-NLS-1$
int start= context.getStart();
int end= context.getEnd();
IRegion region= new Region(start, end - start);
Template[] templates= JavaScriptPlugin.getDefault().getTemplateStore().getTemplates();
if (selection.y == 0) {
for (int i= 0; i != templates.length; i++)
if (context.canEvaluate(templates[i]))
fProposals.add(new TemplateProposal(templates[i], context, region, JavaPluginImages.get(JavaPluginImages.IMG_OBJS_TEMPLATE)));
} else {
if (context.getKey().length() == 0)
context.setForceEvaluation(true);
boolean multipleLinesSelected= areMultipleLinesSelected(viewer);
for (int i= 0; i != templates.length; i++) {
Template template= templates[i];
if (context.canEvaluate(template) &&
template.getContextTypeId().equals(context.getContextType().getId()) &&
(!multipleLinesSelected && template.getPattern().indexOf($_WORD_SELECTION) != -1 || (multipleLinesSelected && template.getPattern().indexOf($_LINE_SELECTION) != -1)))
{
fProposals.add(new TemplateProposal(templates[i], context, region, JavaPluginImages.get(JavaPluginImages.IMG_OBJS_TEMPLATE)));
}
}
}
}
/**
* Returns <code>true</code> if one line is completely selected or if multiple lines are selected.
* Being completely selected means that all characters except the new line characters are
* selected.
*
* @return <code>true</code> if one or multiple lines are selected
*
*/
private boolean areMultipleLinesSelected(ITextViewer viewer) {
if (viewer == null)
return false;
Point s= viewer.getSelectedRange();
if (s.y == 0)
return false;
try {
IDocument document= viewer.getDocument();
int startLine= document.getLineOfOffset(s.x);
int endLine= document.getLineOfOffset(s.x + s.y);
IRegion line= document.getLineInformation(startLine);
return startLine != endLine || (s.x == line.getOffset() && s.y == line.getLength());
} catch (BadLocationException x) {
return false;
}
}
}