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 import org.eclipse.jface.text.Assert;
  14 import org.eclipse.jface.text.BadLocationException;
  15 import org.eclipse.jface.text.IDocument;
  16 import org.eclipse.jface.text.IRegion;
  17 import org.eclipse.jface.text.ITextViewer;
  18 import org.eclipse.jface.text.TextPresentation;
  19 import org.eclipse.jface.text.contentassist.IContextInformation;
  20 import org.eclipse.jface.text.contentassist.IContextInformationPresenter;
  21 import org.eclipse.jface.text.contentassist.IContextInformationValidator;
  22 import org.eclipse.swt.SWT;
  23 import org.eclipse.swt.custom.StyleRange;
  24
  25 public class JavaParameterListValidator implements
  26                 IContextInformationValidator, IContextInformationPresenter {
  27
  28         private int fPosition;
  29
  30         private ITextViewer fViewer;
  31
  32         private IContextInformation fInformation;
  33
  34         private int fCurrentParameter;
  35
  36         public JavaParameterListValidator() {
  37         }
  38
  39         /**
  40          * @see IContextInformationValidator#install(IContextInformation,
  41          *      ITextViewer, int)
  42          * @see IContextInformationPresenter#install(IContextInformation,
  43          *      ITextViewer, int)
  44          */
  45         public void install(IContextInformation info, ITextViewer viewer,
  46                         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)
  55                         throws BadLocationException {
  56                 while (pos < end) {
  57                         char curr = d.getChar(pos);
  58                         pos++;
  59                         if (curr == '*') {
  60                                 if (pos < end && d.getChar(pos) == '/') {
  61                                         return pos + 1;
  62                                 }
  63                         }
  64                 }
  65                 return end;
  66         }
  67
  68         private int getStringEnd(IDocument d, int pos, int end, char ch)
  69                         throws BadLocationException {
  70                 while (pos < end) {
  71                         char curr = d.getChar(pos);
  72                         pos++;
  73                         if (curr == '\\') {
  74                                 // ignore escaped characters
  75                                 pos++;
  76                         } else if (curr == ch) {
  77                                 return pos;
  78                         }
  79                 }
  80                 return end;
  81         }
  82
  83         private int getCharCount(IDocument document, int start, int end,
  84                         String increments, String decrements, boolean considerNesting)
  85                         throws BadLocationException {
  86
  87                 Assert.isTrue((increments.length() != 0 || decrements.length() != 0)
  88                                 && !increments.equals(decrements));
  89
  90                 int nestingLevel = 0;
  91                 int charCount = 0;
  92                 while (start < end) {
  93                         char curr = document.getChar(start++);
  94                         switch (curr) {
  95                         case '/':
  96                                 if (start < end) {
  97                                         char next = document.getChar(start);
  98                                         if (next == '*') {
  99                                                 // a comment starts, advance to the comment end
 100                                                 start = getCommentEnd(document, start + 1, end);
 101                                         } else if (next == '/') {
 102                                                 // '//'-comment: nothing to do anymore on this line
 103                                                 start = end;
 104                                         }
 105                                 }
 106                                 break;
 107                         case '*':
 108                                 if (start < end) {
 109                                         char next = document.getChar(start);
 110                                         if (next == '/') {
 111                                                 // we have been in a comment: forget what we read before
 112                                                 charCount = 0;
 113                                                 ++start;
 114                                         }
 115                                 }
 116                                 break;
 117                         case '"':
 118                         case '\'':
 119                                 start = getStringEnd(document, start, end, curr);
 120                                 break;
 121                         default:
 122
 123                                 if (considerNesting) {
 124
 125                                         if ('(' == curr)
 126                                                 ++nestingLevel;
 127                                         else if (')' == curr)
 128                                                 --nestingLevel;
 129
 130                                         if (nestingLevel != 0)
 131                                                 break;
 132                                 }
 133
 134                                 if (increments.indexOf(curr) >= 0) {
 135                                         ++charCount;
 136                                 }
 137
 138                                 if (decrements.indexOf(curr) >= 0) {
 139                                         --charCount;
 140                                 }
 141                         }
 142                 }
 143
 144                 return charCount;
 145         }
 146
 147         /**
 148          * @see IContextInformationValidator#isContextInformationValid(int)
 149          */
 150         public boolean isContextInformationValid(int position) {
 151
 152                 try {
 153                         if (position < fPosition)
 154                                 return false;
 155
 156                         IDocument document = fViewer.getDocument();
 157                         IRegion line = document.getLineInformationOfOffset(fPosition);
 158
 159                         if (position < line.getOffset() || position >= document.getLength())
 160                                 return false;
 161
 162                         return getCharCount(document, fPosition, position,
 163                                         "(<", ")>", false) >= 0; //$NON-NLS-1$//$NON-NLS-2$
 164
 165                 } catch (BadLocationException x) {
 166                         return false;
 167                 }
 168         }
 169
 170         /**
 171          * @see IContextInformationPresenter#updatePresentation(int,
 172          *      TextPresentation)
 173          */
 174         public boolean updatePresentation(int position,
 175                         TextPresentation presentation) {
 176
 177                 int currentParameter = -1;
 178
 179                 try {
 180                         currentParameter = getCharCount(fViewer.getDocument(), fPosition,
 181                                         position, ",", "", true); //$NON-NLS-1$//$NON-NLS-2$
 182                 } catch (BadLocationException x) {
 183                         return false;
 184                 }
 185
 186                 if (fCurrentParameter != -1) {
 187                         if (currentParameter == fCurrentParameter)
 188                                 return false;
 189                 }
 190
 191                 presentation.clear();
 192                 fCurrentParameter = currentParameter;
 193
 194                 String s = fInformation.getInformationDisplayString();
 195                 int start = 0;
 196                 int occurrences = 0;
 197                 while (occurrences < fCurrentParameter) {
 198                         int found = s.indexOf(',', start);
 199                         if (found == -1)
 200                                 break;
 201                         start = found + 1;
 202                         ++occurrences;
 203                 }
 204
 205                 if (occurrences < fCurrentParameter) {
 206                         presentation.addStyleRange(new StyleRange(0, s.length(), null,
 207                                         null, SWT.NORMAL));
 208                         return true;
 209                 }
 210
 211                 if (start == -1)
 212                         start = 0;
 213
 214                 int end = s.indexOf(',', start);
 215                 if (end == -1)
 216                         end = s.length();
 217
 218                 if (start > 0)
 219                         presentation.addStyleRange(new StyleRange(0, start, null, null,
 220                                         SWT.NORMAL));
 221
 222                 if (end > start)
 223                         presentation.addStyleRange(new StyleRange(start, end - start, null,
 224                                         null, SWT.BOLD));
 225
 226                 if (end < s.length())
 227                         presentation.addStyleRange(new StyleRange(end, s.length() - end,
 228                                         null, null, SWT.NORMAL));
 229
 230                 return true;
 231         }
 232 }