net.sourceforge.phpeclipse/src/net/sourceforge/phpdt/internal/ui/text/java/JavaParameterListValidator.java

   1 /*******************************************************************************
   2  * Copyright (c) 2000, 2005 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 net.sourceforge.phpdt.internal.ui.text.java;
  12
  13
  14 import org.eclipse.swt.SWT;
  15 import org.eclipse.swt.custom.StyleRange;
  16
  17 import org.eclipse.jface.text.Assert;
  18 import org.eclipse.jface.text.BadLocationException;
  19 import org.eclipse.jface.text.IDocument;
  20 import org.eclipse.jface.text.IRegion;
  21 import org.eclipse.jface.text.ITextViewer;
  22 import org.eclipse.jface.text.TextPresentation;
  23 import org.eclipse.jface.text.contentassist.IContextInformation;
  24 import org.eclipse.jface.text.contentassist.IContextInformationPresenter;
  25 import org.eclipse.jface.text.contentassist.IContextInformationValidator;
  26
  27
  28
  29 public class JavaParameterListValidator implements IContextInformationValidator, IContextInformationPresenter {
  30
  31         private int fPosition;
  32         private ITextViewer fViewer;
  33         private IContextInformation fInformation;
  34
  35         private int fCurrentParameter;
  36
  37
  38
  39         public JavaParameterListValidator() {
  40         }
  41
  42         /**
  43          * @see IContextInformationValidator#install(IContextInformation, ITextViewer, int)
  44          * @see IContextInformationPresenter#install(IContextInformation, ITextViewer, int)
  45          */
  46         public void install(IContextInformation info, ITextViewer viewer, int documentPosition) {
  47                 fPosition= documentPosition;
  48                 fViewer= viewer;
  49                 fInformation= info;
  50
  51                 fCurrentParameter= -1;
  52         }
  53
  54         private int getCommentEnd(IDocument d, int pos, int end) throws BadLocationException {
  55                 while (pos < end) {
  56                         char curr= d.getChar(pos);
  57                         pos++;
  58                         if (curr == '*') {
  59                                 if (pos < end && d.getChar(pos) == '/') {
  60                                         return pos + 1;
  61                                 }
  62                         }
  63                 }
  64                 return end;
  65         }
  66
  67         private int getStringEnd(IDocument d, int pos, int end, char ch) throws BadLocationException {
  68                 while (pos < end) {
  69                         char curr= d.getChar(pos);
  70                         pos++;
  71                         if (curr == '\\') {
  72                                 // ignore escaped characters
  73                                 pos++;
  74                         } else if (curr == ch) {
  75                                 return pos;
  76                         }
  77                 }
  78                 return end;
  79         }
  80
  81         private int getCharCount(IDocument document, int start, int end, String increments, String decrements, boolean considerNesting) throws BadLocationException {
  82
  83                 Assert.isTrue((increments.length() != 0 || decrements.length() != 0) && !increments.equals(decrements));
  84
  85                 int nestingLevel= 0;
  86                 int charCount= 0;
  87                 while (start < end) {
  88                         char curr= document.getChar(start++);
  89                         switch (curr) {
  90                                 case '/':
  91                                         if (start < end) {
  92                                                 char next= document.getChar(start);
  93                                                 if (next == '*') {
  94                                                         // a comment starts, advance to the comment end
  95                                                         start= getCommentEnd(document, start + 1, end);
  96                                                 } else if (next == '/') {
  97                                                         // '//'-comment: nothing to do anymore on this line
  98                                                         start= end;
  99                                                 }
 100                                         }
 101                                         break;
 102                                 case '*':
 103                                         if (start < end) {
 104                                                 char next= document.getChar(start);
 105                                                 if (next == '/') {
 106                                                         // we have been in a comment: forget what we read before
 107                                                         charCount= 0;
 108                                                         ++ start;
 109                                                 }
 110                                         }
 111                                         break;
 112                                 case '"':
 113                                 case '\'':
 114                                         start= getStringEnd(document, start, end, curr);
 115                                         break;
 116                                 default:
 117
 118                                         if (considerNesting) {
 119
 120                                                 if ('(' == curr)
 121                                                         ++ nestingLevel;
 122                                                 else if (')' == curr)
 123                                                         -- nestingLevel;
 124
 125                                                 if (nestingLevel != 0)
 126                                                         break;
 127                                         }
 128
 129                                         if (increments.indexOf(curr) >= 0) {
 130                                                 ++ charCount;
 131                                         }
 132
 133                                         if (decrements.indexOf(curr) >= 0) {
 134                                                 -- charCount;
 135                                         }
 136                         }
 137                 }
 138
 139                 return charCount;
 140         }
 141
 142         /**
 143          * @see IContextInformationValidator#isContextInformationValid(int)
 144          */
 145         public boolean isContextInformationValid(int position) {
 146
 147                 try {
 148                         if (position < fPosition)
 149                                 return false;
 150
 151                         IDocument document= fViewer.getDocument();
 152                         IRegion line= document.getLineInformationOfOffset(fPosition);
 153
 154                         if (position < line.getOffset() || position >= document.getLength())
 155                                 return false;
 156
 157                         return getCharCount(document, fPosition, position, "(<", ")>", false) >= 0;  //$NON-NLS-1$//$NON-NLS-2$
 158
 159                 } catch (BadLocationException x) {
 160                         return false;
 161                 }
 162         }
 163
 164         /**
 165          * @see IContextInformationPresenter#updatePresentation(int, TextPresentation)
 166          */
 167         public boolean updatePresentation(int position, TextPresentation presentation) {
 168
 169                 int currentParameter= -1;
 170
 171                 try {
 172                         currentParameter= getCharCount(fViewer.getDocument(), fPosition, position, ",", "", true);  //$NON-NLS-1$//$NON-NLS-2$
 173                 } catch (BadLocationException x) {
 174                         return false;
 175                 }
 176
 177                 if (fCurrentParameter != -1) {
 178                         if (currentParameter == fCurrentParameter)
 179                                 return false;
 180                 }
 181
 182                 presentation.clear();
 183                 fCurrentParameter= currentParameter;
 184
 185                 String s= fInformation.getInformationDisplayString();
 186                 int start= 0;
 187                 int occurrences= 0;
 188                 while (occurrences < fCurrentParameter) {
 189                         int found= s.indexOf(',', start);
 190                         if (found == -1)
 191                                 break;
 192                         start= found + 1;
 193                         ++ occurrences;
 194                 }
 195
 196                 if (occurrences < fCurrentParameter) {
 197                         presentation.addStyleRange(new StyleRange(0, s.length(), null, null, SWT.NORMAL));
 198                         return true;
 199                 }
 200
 201                 if (start == -1)
 202                         start= 0;
 203
 204                 int end= s.indexOf(',', start);
 205                 if (end == -1)
 206                         end= s.length();
 207
 208                 if (start > 0)
 209                         presentation.addStyleRange(new StyleRange(0, start, null, null, SWT.NORMAL));
 210
 211                 if (end > start)
 212                         presentation.addStyleRange(new StyleRange(start, end - start, null, null, SWT.BOLD));
 213
 214                 if (end < s.length())
 215                         presentation.addStyleRange(new StyleRange(end, s.length() - end, null, null, SWT.NORMAL));
 216
 217                 return true;
 218         }
 219 }
 220