case-study/jdt-after/ui/org/eclipse/jdt/internal/ui/text/template/contentassist/TemplateEngine.java

   1 /*******************************************************************************
   2  * Copyright (c) 2000, 2011 IBM Corporation and others.
   3  * All rights reserved. This program and the accompanying materials
   4  * are made available under the terms of the Eclipse Public License v1.0
   5  * which accompanies this distribution, and is available at
   6  * http://www.eclipse.org/legal/epl-v10.html
   7  *
   8  * Contributors:
   9  *     IBM Corporation - initial API and implementation
  10  *******************************************************************************/
  11 package org.eclipse.jdt.internal.ui.text.template.contentassist;
  12
  13 import java.util.ArrayList;
  14 import java.util.HashMap;
  15 import java.util.Iterator;
  16 import java.util.Map;
  17 import java.util.Map.Entry;
  18
  19 import org.eclipse.swt.graphics.Image;
  20 import org.eclipse.swt.graphics.Point;
  21
  22 import org.eclipse.core.runtime.Assert;
  23
  24 import org.eclipse.jface.text.BadLocationException;
  25 import org.eclipse.jface.text.IDocument;
  26 import org.eclipse.jface.text.IRegion;
  27 import org.eclipse.jface.text.ITextViewer;
  28 import org.eclipse.jface.text.Position;
  29 import org.eclipse.jface.text.Region;
  30 import org.eclipse.jface.text.templates.GlobalTemplateVariables;
  31 import org.eclipse.jface.text.templates.Template;
  32 import org.eclipse.jface.text.templates.TemplateContextType;
  33
  34 import org.eclipse.jdt.core.ICompilationUnit;
  35
  36 import org.eclipse.jdt.internal.corext.template.java.CompilationUnitContext;
  37 import org.eclipse.jdt.internal.corext.template.java.CompilationUnitContextType;
  38 import org.eclipse.jdt.internal.corext.template.java.SWTContextType;
  39
  40 import org.eclipse.jdt.internal.ui.JavaPlugin;
  41 import org.eclipse.jdt.internal.ui.JavaPluginImages;
  42
  43
  44 public class TemplateEngine {
  45
  46         private static final String $_LINE_SELECTION= "${" + GlobalTemplateVariables.LineSelection.NAME + "}"; //$NON-NLS-1$ //$NON-NLS-2$
  47         private static final String $_WORD_SELECTION= "${" + GlobalTemplateVariables.WordSelection.NAME + "}"; //$NON-NLS-1$ //$NON-NLS-2$
  48
  49         /** The context type. */
  50         private TemplateContextType fContextType;
  51         /** The result proposals. */
  52         private ArrayList<TemplateProposal> fProposals= new ArrayList<TemplateProposal>();
  53         /** Positions created on the key documents to remove in reset. */
  54         private final Map<IDocument, Position> fPositions= new HashMap<IDocument, Position>();
  55
  56         /**
  57          * Creates the template engine for the given <code>contextType</code>.
  58          * <p>
  59          * The <code>JavaPlugin.getDefault().getTemplateContextRegistry()</code>
  60          * defines the supported context types.</p>
  61          *
  62          * @param contextType the context type
  63          */
  64         public TemplateEngine(TemplateContextType contextType) {
  65                 Assert.isNotNull(contextType);
  66                 fContextType= contextType;
  67         }
  68
  69         /**
  70          * Empties the collector.
  71          */
  72         public void reset() {
  73                 fProposals.clear();
  74                 for (Iterator<Entry<IDocument, Position>> it= fPositions.entrySet().iterator(); it.hasNext();) {
  75                         Entry<IDocument, Position> entry= it.next();
  76                         IDocument doc= entry.getKey();
  77                         Position position= entry.getValue();
  78                         doc.removePosition(position);
  79                 }
  80                 fPositions.clear();
  81         }
  82
  83         /**
  84          * Returns the array of matching templates.
  85          *
  86          * @return the template proposals
  87          */
  88         public TemplateProposal[] getResults() {
  89                 return fProposals.toArray(new TemplateProposal[fProposals.size()]);
  90         }
  91
  92         /**
  93          * Inspects the context of the compilation unit around <code>completionPosition</code>
  94          * and feeds the collector with proposals.
  95          * @param viewer the text viewer
  96          * @param completionPosition the context position in the document of the text viewer
  97          * @param compilationUnit the compilation unit (may be <code>null</code>)
  98          */
  99         public void complete(ITextViewer viewer, int completionPosition, ICompilationUnit compilationUnit) {
 100             IDocument document= viewer.getDocument();
 101
 102                 if (!(fContextType instanceof CompilationUnitContextType))
 103                         return;
 104
 105                 Point selection= viewer.getSelectedRange();
 106                 Position position= new Position(completionPosition, selection.y);
 107
 108                 // remember selected text
 109                 String selectedText= null;
 110                 if (selection.y != 0) {
 111                         try {
 112                                 selectedText= document.get(selection.x, selection.y);
 113                                 document.addPosition(position);
 114                                 fPositions.put(document, position);
 115                         } catch (BadLocationException e) {}
 116                 }
 117
 118                 CompilationUnitContext context= ((CompilationUnitContextType) fContextType).createContext(document, position, compilationUnit);
 119                 context.setVariable("selection", selectedText); //$NON-NLS-1$
 120                 int start= context.getStart();
 121                 int end= context.getEnd();
 122                 IRegion region= new Region(start, end - start);
 123
 124                 Template[] templates= JavaPlugin.getDefault().getTemplateStore().getTemplates();
 125
 126                 if (selection.y == 0) {
 127                         for (int i= 0; i != templates.length; i++) {
 128                                 Template template= templates[i];
 129                                 if (context.canEvaluate(template)) {
 130                                         fProposals.add(new TemplateProposal(template, context, region, getImage()));
 131                                 }
 132                         }
 133                 } else {
 134
 135                         context.generated_551997803931588642();
 136
 137                         boolean multipleLinesSelected= areMultipleLinesSelected(viewer);
 138
 139                         for (int i= 0; i != templates.length; i++) {
 140                                 Template template= templates[i];
 141                                 if (context.canEvaluate(template) &&
 142                                         (!multipleLinesSelected && template.getPattern().indexOf($_WORD_SELECTION) != -1 || (multipleLinesSelected && template.getPattern().indexOf($_LINE_SELECTION) != -1)))
 143                                 {
 144                                         fProposals.add(new TemplateProposal(templates[i], context, region, getImage()));
 145                                 }
 146                         }
 147                 }
 148         }
 149
 150         private Image getImage() {
 151                 if (fContextType instanceof SWTContextType)
 152                         return JavaPluginImages.get(JavaPluginImages.IMG_OBJS_SWT_TEMPLATE);
 153                 else
 154                         return JavaPluginImages.get(JavaPluginImages.IMG_OBJS_TEMPLATE);
 155         }
 156
 157         /**
 158          * Returns <code>true</code> if one line is completely selected or if multiple lines are selected.
 159          * Being completely selected means that all characters except the new line characters are
 160          * selected.
 161          *
 162          * @param viewer the text viewer
 163          * @return <code>true</code> if one or multiple lines are selected
 164          * @since 2.1
 165          */
 166         private boolean areMultipleLinesSelected(ITextViewer viewer) {
 167                 if (viewer == null)
 168                         return false;
 169
 170                 Point s= viewer.getSelectedRange();
 171                 if (s.y == 0)
 172                         return false;
 173
 174                 try {
 175
 176                         IDocument document= viewer.getDocument();
 177                         int startLine= document.getLineOfOffset(s.x);
 178                         int endLine= document.getLineOfOffset(s.x + s.y);
 179                         IRegion line= document.getLineInformation(startLine);
 180                         return startLine != endLine || (s.x == line.getOffset() && s.y == line.getLength());
 181
 182                 } catch (BadLocationException x) {
 183                         return false;
 184                 }
 185         }
 186 }