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

   1 package net.sourceforge.phpdt.internal.ui.text;
   2
   3 /*
   4  * (c) Copyright IBM Corp. 2000, 2001.
   5  * All Rights Reserved.
   6  */
   7
   8 import java.io.IOException;
   9
  10 import org.eclipse.jface.text.BadLocationException;
  11 import org.eclipse.jface.text.IDocument;
  12 import org.eclipse.jface.text.IRegion;
  13 import org.eclipse.jface.text.Region;
  14 import org.eclipse.jface.text.source.ICharacterPairMatcher;
  15
  16 /**
  17  * Helper class for match pairs of characters.
  18  */
  19 public class PHPPairMatcher implements ICharacterPairMatcher {
  20
  21
  22         public static final int LEFT=      1;
  23         public static final int RIGHT= 2;
  24
  25
  26         protected char[] fPairs;
  27         protected IDocument fDocument;
  28         protected int fOffset;
  29
  30         protected int fStartPos;
  31         protected int fEndPos;
  32         protected int fAnchor;
  33
  34         protected PHPCodeReader fReader= new PHPCodeReader();
  35
  36
  37         public PHPPairMatcher(char[] pairs) {
  38                 fPairs= pairs;
  39         }
  40
  41         /*
  42          * @see org.eclipse.jface.text.source.ICharacterPairMatcher#clear()
  43          */
  44         public void clear() {
  45                 if (fReader != null) {
  46                         try {
  47                                 fReader.close();
  48                         } catch (IOException x) {
  49                                 // ignore
  50                         }
  51                 }
  52         }
  53
  54         public IRegion match(IDocument document, int offset) {
  55
  56                 fOffset= offset;
  57
  58                 if (fOffset < 0)
  59                         return null;
  60
  61                 fDocument= document;
  62
  63                 if (matchPairsAt() && fStartPos != fEndPos)
  64                         return new Region(fStartPos, fEndPos - fStartPos + 1);
  65
  66                 return null;
  67         }
  68
  69         public int getAnchor() {
  70                 return fAnchor;
  71         }
  72
  73         public void dispose() {
  74                 fDocument= null;
  75                 if (fReader != null) {
  76                         try {
  77                                 fReader.close();
  78                         } catch (IOException x) {
  79                                 // ignore
  80                         }
  81                         fReader= null;
  82                 }
  83         }
  84
  85         protected boolean matchPairsAt() {
  86
  87                 int i;
  88                 int pairIndex1= fPairs.length;
  89                 int pairIndex2= fPairs.length;
  90
  91                 fStartPos= -1;
  92                 fEndPos= -1;
  93
  94                 // get the chars preceding and following the start position
  95                 try {
  96
  97                         char prevChar= fDocument.getChar(Math.max(fOffset - 1, 0));
  98                         char nextChar= fDocument.getChar(fOffset);
  99
 100                         // search for opening peer character next to the activation point
 101                         for (i= 0; i < fPairs.length; i= i + 2) {
 102                                 if (nextChar == fPairs[i]) {
 103                                         fStartPos= fOffset;
 104                                         pairIndex1= i;
 105                                 } else if (prevChar == fPairs[i]) {
 106                                         fStartPos= fOffset - 1;
 107                                         pairIndex1= i;
 108                                 }
 109                         }
 110
 111                         // search for closing peer character next to the activation point
 112                         for (i= 1; i < fPairs.length; i= i + 2) {
 113                                 if (prevChar == fPairs[i]) {
 114                                         fEndPos= fOffset - 1;
 115                                         pairIndex2= i;
 116                                 } else if (nextChar == fPairs[i]) {
 117                                         fEndPos= fOffset;
 118                                         pairIndex2= i;
 119                                 }
 120                         }
 121
 122                         if (fEndPos > -1) {
 123                                 fAnchor= RIGHT;
 124                                 fStartPos= searchForOpeningPeer(fEndPos, fPairs[pairIndex2 - 1], fPairs[pairIndex2], fDocument);
 125                                 if (fStartPos > -1)
 126                                         return true;
 127                                 else
 128                                         fEndPos= -1;
 129                         }       else if (fStartPos > -1) {
 130                                 fAnchor= LEFT;
 131                                 fEndPos= searchForClosingPeer(fStartPos, fPairs[pairIndex1], fPairs[pairIndex1 + 1], fDocument);
 132                                 if (fEndPos > -1)
 133                                         return true;
 134                                 else
 135                                         fStartPos= -1;
 136                         }
 137
 138                 } catch (BadLocationException x) {
 139                 } catch (IOException x) {
 140                 }
 141
 142                 return false;
 143         }
 144
 145         protected int searchForClosingPeer(int offset, int openingPeer, int closingPeer, IDocument document) throws IOException {
 146
 147                 fReader.configureForwardReader(document, offset + 1, document.getLength(), true, true);
 148
 149                 int stack= 1;
 150                 int c= fReader.read();
 151                 while (c != PHPCodeReader.EOF) {
 152                         if (c == openingPeer && c != closingPeer)
 153                                 stack++;
 154                         else if (c == closingPeer)
 155                                 stack--;
 156
 157                         if (stack == 0)
 158                                 return fReader.getOffset();
 159
 160                         c= fReader.read();
 161                 }
 162
 163                 return  -1;
 164         }
 165
 166         protected int searchForOpeningPeer(int offset, int openingPeer, int closingPeer, IDocument document) throws IOException {
 167
 168                 fReader.configureBackwardReader(document, offset, true, true);
 169
 170                 int stack= 1;
 171                 int c= fReader.read();
 172                 while (c != PHPCodeReader.EOF) {
 173                         if (c == closingPeer && c != openingPeer)
 174                                 stack++;
 175                         else if (c == openingPeer)
 176                                 stack--;
 177
 178                         if (stack == 0)
 179                                 return fReader.getOffset();
 180
 181                         c= fReader.read();
 182                 }
 183
 184                 return -1;
 185         }
 186 }