ext/scintilla/lexlib/LexAccessor.h

   1 // Scintilla source code edit control
   2 /** @file LexAccessor.h
   3  ** Interfaces between Scintilla and lexers.
   4  **/
   5 // Copyright 1998-2010 by Neil Hodgson <neilh@scintilla.org>
   6 // The License.txt file describes the conditions under which this software may be distributed.
   7
   8 #ifndef LEXACCESSOR_H
   9 #define LEXACCESSOR_H
  10
  11 #ifdef SCI_NAMESPACE
  12 namespace Scintilla {
  13 #endif
  14
  15 class LexAccessor {
  16 private:
  17         IDocument *pAccess;
  18         enum {extremePosition=0x7FFFFFFF};
  19         /** @a bufferSize is a trade off between time taken to copy the characters
  20          * and retrieval overhead.
  21          * @a slopSize positions the buffer before the desired position
  22          * in case there is some backtracking. */
  23         enum {bufferSize=4000, slopSize=bufferSize/8};
  24         char buf[bufferSize+1];
  25         int startPos;
  26         int endPos;
  27         int codePage;
  28         int lenDoc;
  29         int mask;
  30         char styleBuf[bufferSize];
  31         int validLen;
  32         char chFlags;
  33         char chWhile;
  34         unsigned int startSeg;
  35         int startPosStyling;
  36
  37         void Fill(int position) {
  38                 startPos = position - slopSize;
  39                 if (startPos + bufferSize > lenDoc)
  40                         startPos = lenDoc - bufferSize;
  41                 if (startPos < 0)
  42                         startPos = 0;
  43                 endPos = startPos + bufferSize;
  44                 if (endPos > lenDoc)
  45                         endPos = lenDoc;
  46
  47                 pAccess->GetCharRange(buf, startPos, endPos-startPos);
  48                 buf[endPos-startPos] = '\0';
  49         }
  50
  51 public:
  52         LexAccessor(IDocument *pAccess_) :
  53                 pAccess(pAccess_), startPos(extremePosition), endPos(0),
  54                 codePage(pAccess->CodePage()), lenDoc(pAccess->Length()),
  55                 mask(127), validLen(0), chFlags(0), chWhile(0),
  56                 startSeg(0), startPosStyling(0) {
  57         }
  58         char operator[](int position) {
  59                 if (position < startPos || position >= endPos) {
  60                         Fill(position);
  61                 }
  62                 return buf[position - startPos];
  63         }
  64         /** Safe version of operator[], returning a defined value for invalid position. */
  65         char SafeGetCharAt(int position, char chDefault=' ') {
  66                 if (position < startPos || position >= endPos) {
  67                         Fill(position);
  68                         if (position < startPos || position >= endPos) {
  69                                 // Position is outside range of document
  70                                 return chDefault;
  71                         }
  72                 }
  73                 return buf[position - startPos];
  74         }
  75         bool IsLeadByte(char ch) {
  76                 return pAccess->IsDBCSLeadByte(ch);
  77         }
  78
  79         bool Match(int pos, const char *s) {
  80                 for (int i=0; *s; i++) {
  81                         if (*s != SafeGetCharAt(pos+i))
  82                                 return false;
  83                         s++;
  84                 }
  85                 return true;
  86         }
  87         char StyleAt(int position) {
  88                 return static_cast<char>(pAccess->StyleAt(position) & mask);
  89         }
  90         int GetLine(int position) {
  91                 return pAccess->LineFromPosition(position);
  92         }
  93         int LineStart(int line) {
  94                 return pAccess->LineStart(line);
  95         }
  96         int LevelAt(int line) {
  97                 return pAccess->GetLevel(line);
  98         }
  99         int Length() const {
 100                 return lenDoc;
 101         }
 102         void Flush() {
 103                 startPos = extremePosition;
 104                 if (validLen > 0) {
 105                         pAccess->SetStyles(validLen, styleBuf);
 106                         startPosStyling += validLen;
 107                         validLen = 0;
 108                 }
 109         }
 110         int GetLineState(int line) {
 111                 return pAccess->GetLineState(line);
 112         }
 113         int SetLineState(int line, int state) {
 114                 return pAccess->SetLineState(line, state);
 115         }
 116         // Style setting
 117         void StartAt(unsigned int start, char chMask=31) {
 118                 // Store the mask specified for use with StyleAt.
 119                 mask = chMask;
 120                 pAccess->StartStyling(start, chMask);
 121                 startPosStyling = start;
 122         }
 123         void SetFlags(char chFlags_, char chWhile_) {
 124                 chFlags = chFlags_;
 125                 chWhile = chWhile_;
 126         }
 127         unsigned int GetStartSegment() const {
 128                 return startSeg;
 129         }
 130         void StartSegment(unsigned int pos) {
 131                 startSeg = pos;
 132         }
 133         void ColourTo(unsigned int pos, int chAttr) {
 134                 // Only perform styling if non empty range
 135                 if (pos != startSeg - 1) {
 136                         assert(pos >= startSeg);
 137                         if (pos < startSeg) {
 138                                 return;
 139                         }
 140
 141                         if (validLen + (pos - startSeg + 1) >= bufferSize)
 142                                 Flush();
 143                         if (validLen + (pos - startSeg + 1) >= bufferSize) {
 144                                 // Too big for buffer so send directly
 145                                 pAccess->SetStyleFor(pos - startSeg + 1, static_cast<char>(chAttr));
 146                         } else {
 147                                 if (chAttr != chWhile)
 148                                         chFlags = 0;
 149                                 chAttr |= chFlags;
 150                                 for (unsigned int i = startSeg; i <= pos; i++) {
 151                                         assert((startPosStyling + validLen) < Length());
 152                                         styleBuf[validLen++] = static_cast<char>(chAttr);
 153                                 }
 154                         }
 155                 }
 156                 startSeg = pos+1;
 157         }
 158         void SetLevel(int line, int level) {
 159                 pAccess->SetLevel(line, level);
 160         }
 161         void IndicatorFill(int start, int end, int indicator, int value) {
 162                 pAccess->DecorationSetCurrentIndicator(indicator);
 163                 pAccess->DecorationFillRange(start, value, end - start);
 164         }
 165
 166         void ChangeLexerState(int start, int end) {
 167                 pAccess->ChangeLexerState(start, end);
 168         }
 169 };
 170
 171 #ifdef SCI_NAMESPACE
 172 }
 173 #endif
 174
 175 #endif