case-study/jdt-before/ui/org/eclipse/jdt/internal/ui/text/template/preferences/TemplateVariableProcessor.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.preferences;
  12
  13 import java.util.ArrayList;
  14 import java.util.Collections;
  15 import java.util.Comparator;
  16 import java.util.Iterator;
  17 import java.util.List;
  18
  19 import org.eclipse.jface.text.ITextViewer;
  20 import org.eclipse.jface.text.contentassist.ICompletionProposal;
  21 import org.eclipse.jface.text.contentassist.IContentAssistProcessor;
  22 import org.eclipse.jface.text.contentassist.IContextInformation;
  23 import org.eclipse.jface.text.contentassist.IContextInformationValidator;
  24 import org.eclipse.jface.text.templates.TemplateContextType;
  25 import org.eclipse.jface.text.templates.TemplateVariableResolver;
  26
  27
  28
  29 public class TemplateVariableProcessor implements IContentAssistProcessor {
  30
  31         private static Comparator<TemplateVariableProposal> fgTemplateVariableProposalComparator= new Comparator<TemplateVariableProposal>() {
  32                 public int compare(TemplateVariableProposal proposal0, TemplateVariableProposal proposal1) {
  33                         return proposal0.getDisplayString().compareTo(proposal1.getDisplayString());
  34                 }
  35         };
  36
  37
  38         /** the context type */
  39         private TemplateContextType fContextType;
  40
  41         /**
  42          * Sets the context type.
  43          *
  44          * @param contextType the context type
  45          */
  46         public void setContextType(TemplateContextType contextType) {
  47                 fContextType= contextType;
  48         }
  49
  50         /**
  51          * Gets the context type.
  52          *
  53          * @return the context type
  54          */
  55         public TemplateContextType getContextType() {
  56                 return fContextType;
  57         }
  58
  59         /*
  60          * @see IContentAssistProcessor#computeCompletionProposals(ITextViewer, int)
  61          */
  62         public ICompletionProposal[] computeCompletionProposals(ITextViewer viewer,     int documentOffset) {
  63
  64                 if (fContextType == null)
  65                         return null;
  66
  67                 List<TemplateVariableProposal> proposals= new ArrayList<TemplateVariableProposal>();
  68
  69                 String text= viewer.getDocument().get();
  70                 int start= getStart(text, documentOffset);
  71                 int end= documentOffset;
  72
  73                 String string= text.substring(start, end);
  74                 int colon= string.indexOf(':');
  75                 boolean includeBrace= true;
  76                 int offset= start;
  77                 String prefix= string;
  78                 if (colon != -1) {
  79                         includeBrace= false;
  80                         offset= start + colon + 1;
  81                         prefix= string.substring(colon + 1);
  82                 } else {
  83                         int escape= string.indexOf("${"); //$NON-NLS-1$
  84                         if (escape != -1) {
  85                                 offset= start + escape + 2;
  86                                 includeBrace= false;
  87                                 prefix= string.substring(escape + 2);
  88                         }
  89                 }
  90                 if (prefix.equals("$")) //$NON-NLS-1$
  91                         prefix= ""; //$NON-NLS-1$
  92
  93                 int length= end - offset;
  94
  95                 for (Iterator<TemplateVariableResolver> iterator= fContextType.resolvers(); iterator.hasNext(); ) {
  96                         TemplateVariableResolver variable= iterator.next();
  97
  98                         if (variable.getType().startsWith(prefix))
  99                                 proposals.add(new TemplateVariableProposal(variable, offset, length, viewer, includeBrace));
 100                 }
 101
 102                 Collections.sort(proposals, fgTemplateVariableProposalComparator);
 103                 return proposals.toArray(new ICompletionProposal[proposals.size()]);
 104         }
 105
 106         /* Guesses the start position of the completion */
 107         private int getStart(String string, int end) {
 108                 int start= end;
 109
 110                 if (start >= 1 && string.charAt(start - 1) == '$')
 111                         return start - 1;
 112
 113                 while ((start != 0) && Character.isUnicodeIdentifierPart(string.charAt(start - 1)))
 114                         start--;
 115
 116                 if (start >= 1 && string.charAt(start - 1) == ':') {
 117                         start--;
 118                         while ((start != 0) && Character.isUnicodeIdentifierPart(string.charAt(start - 1)))
 119                                 start--;
 120                 }
 121
 122                 if (start >= 2 && string.charAt(start - 1) == '{' && string.charAt(start - 2) == '$')
 123                         return start - 2;
 124
 125                 return end;
 126         }
 127
 128         /*
 129          * @see IContentAssistProcessor#computeContextInformation(ITextViewer, int)
 130          */
 131         public IContextInformation[] computeContextInformation(ITextViewer viewer, int documentOffset) {
 132                 return null;
 133         }
 134
 135         /*
 136          * @see IContentAssistProcessor#getCompletionProposalAutoActivationCharacters()
 137          */
 138         public char[] getCompletionProposalAutoActivationCharacters() {
 139                 return new char[] {'$'};
 140         }
 141
 142         /*
 143          * @see IContentAssistProcessor#getContextInformationAutoActivationCharacters()
 144          */
 145         public char[] getContextInformationAutoActivationCharacters() {
 146                 return null;
 147         }
 148
 149         /*
 150          * @see IContentAssistProcessor#getErrorMessage()
 151          */
 152         public String getErrorMessage() {
 153                 return null;
 154         }
 155
 156         /*
 157          * @see IContentAssistProcessor#getContextInformationValidator()
 158          */
 159         public IContextInformationValidator getContextInformationValidator() {
 160                 return null;
 161         }
 162
 163 }
 164