diff options
Diffstat (limited to 'generic/tkTextIndex.c')
| -rw-r--r-- | generic/tkTextIndex.c | 616 |
1 files changed, 481 insertions, 135 deletions
diff --git a/generic/tkTextIndex.c b/generic/tkTextIndex.c index 4d2ac8e..8376419 100644 --- a/generic/tkTextIndex.c +++ b/generic/tkTextIndex.c @@ -5,12 +5,12 @@ * text widgets. * * Copyright (c) 1992-1994 The Regents of the University of California. - * Copyright (c) 1994-1995 Sun Microsystems, Inc. + * Copyright (c) 1994-1997 Sun Microsystems, Inc. * * See the file "license.terms" for information on usage and redistribution * of this file, and for a DISCLAIMER OF ALL WARRANTIES. * - * RCS: @(#) $Id: tkTextIndex.c,v 1.2 1998/09/14 18:23:19 stanton Exp $ + * RCS: @(#) $Id: tkTextIndex.c,v 1.3 1999/04/16 01:51:24 stanton Exp $ */ #include "default.h" @@ -34,27 +34,118 @@ static char * StartEnd _ANSI_ARGS_(( char *string, TkTextIndex *indexPtr)); /* - *-------------------------------------------------------------- + *--------------------------------------------------------------------------- * - * TkTextMakeIndex -- + * TkTextMakeByteIndex -- * - * Given a line index and a character index, look things up - * in the B-tree and fill in a TkTextIndex structure. + * Given a line index and a byte index, look things up in the B-tree + * and fill in a TkTextIndex structure. * * Results: - * The structure at *indexPtr is filled in with information - * about the character at lineIndex and charIndex (or the - * closest existing character, if the specified one doesn't - * exist), and indexPtr is returned as result. + * The structure at *indexPtr is filled in with information about the + * character at lineIndex and byteIndex (or the closest existing + * character, if the specified one doesn't exist), and indexPtr is + * returned as result. * * Side effects: * None. * - *-------------------------------------------------------------- + *--------------------------------------------------------------------------- */ TkTextIndex * -TkTextMakeIndex(tree, lineIndex, charIndex, indexPtr) +TkTextMakeByteIndex(tree, lineIndex, byteIndex, indexPtr) + TkTextBTree tree; /* Tree that lineIndex and charIndex refer + * to. */ + int lineIndex; /* Index of desired line (0 means first + * line of text). */ + int byteIndex; /* Byte index of desired character. */ + TkTextIndex *indexPtr; /* Structure to fill in. */ +{ + TkTextSegment *segPtr; + int index; + char *p, *start; + Tcl_UniChar ch; + + indexPtr->tree = tree; + if (lineIndex < 0) { + lineIndex = 0; + byteIndex = 0; + } + if (byteIndex < 0) { + byteIndex = 0; + } + indexPtr->linePtr = TkBTreeFindLine(tree, lineIndex); + if (indexPtr->linePtr == NULL) { + indexPtr->linePtr = TkBTreeFindLine(tree, TkBTreeNumLines(tree)); + byteIndex = 0; + } + if (byteIndex == 0) { + indexPtr->byteIndex = byteIndex; + return indexPtr; + } + + /* + * Verify that the index is within the range of the line and points + * to a valid character boundary. + */ + + index = 0; + for (segPtr = indexPtr->linePtr->segPtr; ; segPtr = segPtr->nextPtr) { + if (segPtr == NULL) { + /* + * Use the index of the last character in the line. Since + * the last character on the line is guaranteed to be a '\n', + * we can back up a constant sizeof(char) bytes. + */ + + indexPtr->byteIndex = index - sizeof(char); + break; + } + if (index + segPtr->size > byteIndex) { + indexPtr->byteIndex = byteIndex; + if ((byteIndex > index) && (segPtr->typePtr == &tkTextCharType)) { + /* + * Prevent UTF-8 character from being split up by ensuring + * that byteIndex falls on a character boundary. If index + * falls in the middle of a UTF-8 character, it will be + * adjusted to the end of that UTF-8 character. + */ + + start = segPtr->body.chars + (byteIndex - index); + p = Tcl_UtfPrev(start, segPtr->body.chars); + p += Tcl_UtfToUniChar(p, &ch); + indexPtr->byteIndex += p - start; + } + break; + } + index += segPtr->size; + } + return indexPtr; +} + +/* + *--------------------------------------------------------------------------- + * + * TkTextMakeCharIndex -- + * + * Given a line index and a character index, look things up in the + * B-tree and fill in a TkTextIndex structure. + * + * Results: + * The structure at *indexPtr is filled in with information about the + * character at lineIndex and charIndex (or the closest existing + * character, if the specified one doesn't exist), and indexPtr is + * returned as result. + * + * Side effects: + * None. + * + *--------------------------------------------------------------------------- + */ + +TkTextIndex * +TkTextMakeCharIndex(tree, lineIndex, charIndex, indexPtr) TkTextBTree tree; /* Tree that lineIndex and charIndex refer * to. */ int lineIndex; /* Index of desired line (0 means first @@ -63,7 +154,9 @@ TkTextMakeIndex(tree, lineIndex, charIndex, indexPtr) TkTextIndex *indexPtr; /* Structure to fill in. */ { register TkTextSegment *segPtr; - int index; + char *p, *start, *end; + int index, offset; + Tcl_UniChar ch; indexPtr->tree = tree; if (lineIndex < 0) { @@ -84,53 +177,76 @@ TkTextMakeIndex(tree, lineIndex, charIndex, indexPtr) * If not, just use the index of the last character in the line. */ - for (index = 0, segPtr = indexPtr->linePtr->segPtr; ; - segPtr = segPtr->nextPtr) { + index = 0; + for (segPtr = indexPtr->linePtr->segPtr; ; segPtr = segPtr->nextPtr) { if (segPtr == NULL) { - indexPtr->charIndex = index-1; + /* + * Use the index of the last character in the line. Since + * the last character on the line is guaranteed to be a '\n', + * we can back up a constant sizeof(char) bytes. + */ + + indexPtr->byteIndex = index - sizeof(char); break; } - index += segPtr->size; - if (index > charIndex) { - indexPtr->charIndex = charIndex; - break; + if (segPtr->typePtr == &tkTextCharType) { + /* + * Turn character offset into a byte offset. + */ + + start = segPtr->body.chars; + end = start + segPtr->size; + for (p = start; p < end; p += offset) { + if (charIndex == 0) { + indexPtr->byteIndex = index; + return indexPtr; + } + charIndex--; + offset = Tcl_UtfToUniChar(p, &ch); + index += offset; + } + } else { + if (charIndex < segPtr->size) { + indexPtr->byteIndex = index; + break; + } + charIndex -= segPtr->size; + index += segPtr->size; } } return indexPtr; } /* - *-------------------------------------------------------------- + *--------------------------------------------------------------------------- * * TkTextIndexToSeg -- * - * Given an index, this procedure returns the segment and - * offset within segment for the index. + * Given an index, this procedure returns the segment and offset + * within segment for the index. * * Results: - * The return value is a pointer to the segment referred to - * by indexPtr; this will always be a segment with non-zero - * size. The variable at *offsetPtr is set to hold the - * integer offset within the segment of the character - * given by indexPtr. + * The return value is a pointer to the segment referred to by + * indexPtr; this will always be a segment with non-zero size. The + * variable at *offsetPtr is set to hold the integer offset within + * the segment of the character given by indexPtr. * * Side effects: * None. * - *-------------------------------------------------------------- + *--------------------------------------------------------------------------- */ TkTextSegment * TkTextIndexToSeg(indexPtr, offsetPtr) - TkTextIndex *indexPtr; /* Text index. */ - int *offsetPtr; /* Where to store offset within - * segment, or NULL if offset isn't - * wanted. */ + CONST TkTextIndex *indexPtr;/* Text index. */ + int *offsetPtr; /* Where to store offset within segment, or + * NULL if offset isn't wanted. */ { - register TkTextSegment *segPtr; + TkTextSegment *segPtr; int offset; - for (offset = indexPtr->charIndex, segPtr = indexPtr->linePtr->segPtr; + for (offset = indexPtr->byteIndex, segPtr = indexPtr->linePtr->segPtr; offset >= segPtr->size; offset -= segPtr->size, segPtr = segPtr->nextPtr) { /* Empty loop body. */ @@ -142,30 +258,29 @@ TkTextIndexToSeg(indexPtr, offsetPtr) } /* - *-------------------------------------------------------------- + *--------------------------------------------------------------------------- * * TkTextSegToOffset -- * - * Given a segment pointer and the line containing it, this - * procedure returns the offset of the segment within its - * line. + * Given a segment pointer and the line containing it, this procedure + * returns the offset of the segment within its line. * * Results: - * The return value is the offset (within its line) of the - * first character in segPtr. + * The return value is the offset (within its line) of the first + * character in segPtr. * * Side effects: * None. * - *-------------------------------------------------------------- + *--------------------------------------------------------------------------- */ int TkTextSegToOffset(segPtr, linePtr) - TkTextSegment *segPtr; /* Segment whose offset is desired. */ - TkTextLine *linePtr; /* Line containing segPtr. */ + CONST TkTextSegment *segPtr;/* Segment whose offset is desired. */ + CONST TkTextLine *linePtr; /* Line containing segPtr. */ { - TkTextSegment *segPtr2; + CONST TkTextSegment *segPtr2; int offset; offset = 0; @@ -177,23 +292,22 @@ TkTextSegToOffset(segPtr, linePtr) } /* - *---------------------------------------------------------------------- + *--------------------------------------------------------------------------- * * TkTextGetIndex -- * - * Given a string, return the line and character indices that - * it describes. + * Given a string, return the index that is described. * * Results: - * The return value is a standard Tcl return result. If - * TCL_OK is returned, then everything went well and the index - * at *indexPtr is filled in; otherwise TCL_ERROR is returned - * and an error message is left in interp->result. + * The return value is a standard Tcl return result. If TCL_OK is + * returned, then everything went well and the index at *indexPtr is + * filled in; otherwise TCL_ERROR is returned and an error message + * is left in the interp's result. * * Side effects: * None. * - *---------------------------------------------------------------------- + *--------------------------------------------------------------------------- */ int @@ -203,8 +317,7 @@ TkTextGetIndex(interp, textPtr, string, indexPtr) char *string; /* Textual description of position. */ TkTextIndex *indexPtr; /* Index structure to fill in. */ { - register char *p; - char *end, *endOfBase; + char *p, *end, *endOfBase; Tcl_HashEntry *hPtr; TkTextTag *tagPtr; TkTextSearch search; @@ -259,8 +372,8 @@ TkTextGetIndex(interp, textPtr, string, indexPtr) goto tryxy; } tagPtr = (TkTextTag *) Tcl_GetHashValue(hPtr); - TkTextMakeIndex(textPtr->tree, 0, 0, &first); - TkTextMakeIndex(textPtr->tree, TkBTreeNumLines(textPtr->tree), 0, + TkTextMakeByteIndex(textPtr->tree, 0, 0, &first); + TkTextMakeByteIndex(textPtr->tree, TkBTreeNumLines(textPtr->tree), 0, &last); TkBTreeStartSearch(&first, &last, tagPtr, &search); if (!TkBTreeCharTagged(&first, tagPtr) && !TkBTreeNextTag(&search)) { @@ -324,7 +437,7 @@ TkTextGetIndex(interp, textPtr, string, indexPtr) } endOfBase = end; } - TkTextMakeIndex(textPtr->tree, lineIndex, charIndex, indexPtr); + TkTextMakeCharIndex(textPtr->tree, lineIndex, charIndex, indexPtr); goto gotBase; } @@ -353,7 +466,7 @@ TkTextGetIndex(interp, textPtr, string, indexPtr) * Base position is end of text. */ - TkTextMakeIndex(textPtr->tree, TkBTreeNumLines(textPtr->tree), + TkTextMakeByteIndex(textPtr->tree, TkBTreeNumLines(textPtr->tree), 0, indexPtr); goto gotBase; } else { @@ -420,13 +533,12 @@ TkTextGetIndex(interp, textPtr, string, indexPtr) } /* - *---------------------------------------------------------------------- + *--------------------------------------------------------------------------- * * TkTextPrintIndex -- - * * - * This procedure generates a string description of an index, - * suitable for reading in again later. + * This procedure generates a string description of an index, suitable + * for reading in again later. * * Results: * The characters pointed to by string are modified. @@ -434,49 +546,69 @@ TkTextGetIndex(interp, textPtr, string, indexPtr) * Side effects: * None. * - *---------------------------------------------------------------------- + *--------------------------------------------------------------------------- */ void TkTextPrintIndex(indexPtr, string) - TkTextIndex *indexPtr; /* Pointer to index. */ + CONST TkTextIndex *indexPtr;/* Pointer to index. */ char *string; /* Place to store the position. Must have * at least TK_POS_CHARS characters. */ { + TkTextSegment *segPtr; + int numBytes, charIndex; + + numBytes = indexPtr->byteIndex; + charIndex = 0; + for (segPtr = indexPtr->linePtr->segPtr; ; segPtr = segPtr->nextPtr) { + if (numBytes <= segPtr->size) { + break; + } + if (segPtr->typePtr == &tkTextCharType) { + charIndex += Tcl_NumUtfChars(segPtr->body.chars, segPtr->size); + } else { + charIndex += segPtr->size; + } + numBytes -= segPtr->size; + } + if (segPtr->typePtr == &tkTextCharType) { + charIndex += Tcl_NumUtfChars(segPtr->body.chars, numBytes); + } else { + charIndex += numBytes; + } sprintf(string, "%d.%d", TkBTreeLineIndex(indexPtr->linePtr) + 1, - indexPtr->charIndex); + charIndex); } /* - *-------------------------------------------------------------- + *--------------------------------------------------------------------------- * * TkTextIndexCmp -- * - * Compare two indices to see which one is earlier in - * the text. + * Compare two indices to see which one is earlier in the text. * * Results: - * The return value is 0 if index1Ptr and index2Ptr refer - * to the same position in the file, -1 if index1Ptr refers - * to an earlier position than index2Ptr, and 1 otherwise. + * The return value is 0 if index1Ptr and index2Ptr refer to the same + * position in the file, -1 if index1Ptr refers to an earlier position + * than index2Ptr, and 1 otherwise. * * Side effects: * None. * - *-------------------------------------------------------------- + *--------------------------------------------------------------------------- */ int TkTextIndexCmp(index1Ptr, index2Ptr) - TkTextIndex *index1Ptr; /* First index. */ - TkTextIndex *index2Ptr; /* Second index. */ + CONST TkTextIndex *index1Ptr; /* First index. */ + CONST TkTextIndex *index2Ptr; /* Second index. */ { int line1, line2; if (index1Ptr->linePtr == index2Ptr->linePtr) { - if (index1Ptr->charIndex < index2Ptr->charIndex) { + if (index1Ptr->byteIndex < index2Ptr->byteIndex) { return -1; - } else if (index1Ptr->charIndex > index2Ptr->charIndex) { + } else if (index1Ptr->byteIndex > index2Ptr->byteIndex) { return 1; } else { return 0; @@ -494,23 +626,23 @@ TkTextIndexCmp(index1Ptr, index2Ptr) } /* - *---------------------------------------------------------------------- + *--------------------------------------------------------------------------- * * ForwBack -- * - * This procedure handles +/- modifiers for indices to adjust - * the index forwards or backwards. + * This procedure handles +/- modifiers for indices to adjust the + * index forwards or backwards. * * Results: - * If the modifier in string is successfully parsed then the - * return value is the address of the first character after the - * modifier, and *indexPtr is updated to reflect the modifier. - * If there is a syntax error in the modifier then NULL is returned. + * If the modifier in string is successfully parsed then the return + * value is the address of the first character after the modifier, + * and *indexPtr is updated to reflect the modifier. If there is a + * syntax error in the modifier then NULL is returned. * * Side effects: * None. * - *---------------------------------------------------------------------- + *--------------------------------------------------------------------------- */ static char * @@ -550,7 +682,7 @@ ForwBack(string, indexPtr) */ units = p; - while ((*p != 0) && !isspace(UCHAR(*p)) && (*p != '+') && (*p != '-')) { + while ((*p != '\0') && !isspace(UCHAR(*p)) && (*p != '+') && (*p != '-')) { p++; } length = p - units; @@ -578,7 +710,18 @@ ForwBack(string, indexPtr) lineIndex = 0; } } - TkTextMakeIndex(indexPtr->tree, lineIndex, indexPtr->charIndex, + /* + * This doesn't work quite right if using a proportional font or + * UTF-8 characters with varying numbers of bytes. The cursor will + * bop around, keeping a constant number of bytes (not characters) + * from the left edge (but making sure not to split any UTF-8 + * characters), regardless of the x-position the index corresponds + * to. The proper way to do this is to get the x-position of the + * index and then pick the character at the same x-position in the + * new line. + */ + + TkTextMakeByteIndex(indexPtr->tree, lineIndex, indexPtr->byteIndex, indexPtr); } else { return NULL; @@ -587,44 +730,42 @@ ForwBack(string, indexPtr) } /* - *---------------------------------------------------------------------- + *--------------------------------------------------------------------------- * - * TkTextIndexForwChars -- + * TkTextIndexForwBytes -- * - * Given an index for a text widget, this procedure creates a - * new index that points "count" characters ahead of the source - * index. + * Given an index for a text widget, this procedure creates a new + * index that points "count" bytes ahead of the source index. * * Results: - * *dstPtr is modified to refer to the character "count" characters - * after srcPtr, or to the last character in the file if there aren't - * "count" characters left in the file. + * *dstPtr is modified to refer to the character "count" bytes after + * srcPtr, or to the last character in the TkText if there aren't + * "count" bytes left. * * Side effects: * None. * - *---------------------------------------------------------------------- + *--------------------------------------------------------------------------- */ - /* ARGSUSED */ void -TkTextIndexForwChars(srcPtr, count, dstPtr) - TkTextIndex *srcPtr; /* Source index. */ - int count; /* How many characters forward to - * move. May be negative. */ - TkTextIndex *dstPtr; /* Destination index: gets modified. */ +TkTextIndexForwBytes(srcPtr, byteCount, dstPtr) + CONST TkTextIndex *srcPtr; /* Source index. */ + int byteCount; /* How many bytes forward to move. May be + * negative. */ + TkTextIndex *dstPtr; /* Destination index: gets modified. */ { TkTextLine *linePtr; TkTextSegment *segPtr; int lineLength; - if (count < 0) { - TkTextIndexBackChars(srcPtr, -count, dstPtr); + if (byteCount < 0) { + TkTextIndexBackBytes(srcPtr, -byteCount, dstPtr); return; } *dstPtr = *srcPtr; - dstPtr->charIndex += count; + dstPtr->byteIndex += byteCount; while (1) { /* * Compute the length of the current line. @@ -641,13 +782,13 @@ TkTextIndexForwChars(srcPtr, count, dstPtr) * Otherwise go on to the next line. */ - if (dstPtr->charIndex < lineLength) { + if (dstPtr->byteIndex < lineLength) { return; } - dstPtr->charIndex -= lineLength; + dstPtr->byteIndex -= lineLength; linePtr = TkBTreeNextLine(dstPtr->linePtr); if (linePtr == NULL) { - dstPtr->charIndex = lineLength - 1; + dstPtr->byteIndex = lineLength - 1; return; } dstPtr->linePtr = linePtr; @@ -655,44 +796,133 @@ TkTextIndexForwChars(srcPtr, count, dstPtr) } /* - *---------------------------------------------------------------------- + *--------------------------------------------------------------------------- * - * TkTextIndexBackChars -- + * TkTextIndexForwChars -- * - * Given an index for a text widget, this procedure creates a - * new index that points "count" characters earlier than the - * source index. + * Given an index for a text widget, this procedure creates a new + * index that points "count" characters ahead of the source index. * * Results: * *dstPtr is modified to refer to the character "count" characters - * before srcPtr, or to the first character in the file if there aren't - * "count" characters earlier than srcPtr. + * after srcPtr, or to the last character in the TkText if there + * aren't "count" characters left in the file. * * Side effects: * None. * - *---------------------------------------------------------------------- + *--------------------------------------------------------------------------- + */ + +void +TkTextIndexForwChars(srcPtr, charCount, dstPtr) + CONST TkTextIndex *srcPtr; /* Source index. */ + int charCount; /* How many characters forward to move. + * May be negative. */ + TkTextIndex *dstPtr; /* Destination index: gets modified. */ +{ + TkTextLine *linePtr; + TkTextSegment *segPtr; + int byteOffset; + char *start, *end, *p; + Tcl_UniChar ch; + + if (charCount < 0) { + TkTextIndexBackChars(srcPtr, -charCount, dstPtr); + return; + } + + *dstPtr = *srcPtr; + + /* + * Find seg that contains src byteIndex. + * Move forward specified number of chars. + */ + + segPtr = TkTextIndexToSeg(dstPtr, &byteOffset); + while (1) { + /* + * Go through each segment in line looking for specified character + * index. + */ + + for ( ; segPtr != NULL; segPtr = segPtr->nextPtr) { + if (segPtr->typePtr == &tkTextCharType) { + start = segPtr->body.chars + byteOffset; + end = segPtr->body.chars + segPtr->size; + for (p = start; p < end; p += Tcl_UtfToUniChar(p, &ch)) { + if (charCount == 0) { + dstPtr->byteIndex += (p - start); + return; + } + charCount--; + } + } else { + if (charCount < segPtr->size - byteOffset) { + dstPtr->byteIndex += charCount; + return; + } + charCount -= segPtr->size - byteOffset; + } + dstPtr->byteIndex += segPtr->size - byteOffset; + byteOffset = 0; + } + + /* + * Go to the next line. If we are at the end of the text item, + * back up one byte (for the terminal '\n' character) and return + * that index. + */ + + linePtr = TkBTreeNextLine(dstPtr->linePtr); + if (linePtr == NULL) { + dstPtr->byteIndex -= sizeof(char); + return; + } + dstPtr->linePtr = linePtr; + dstPtr->byteIndex = 0; + segPtr = dstPtr->linePtr->segPtr; + } +} + +/* + *--------------------------------------------------------------------------- + * + * TkTextIndexBackBytes -- + * + * Given an index for a text widget, this procedure creates a new + * index that points "count" bytes earlier than the source index. + * + * Results: + * *dstPtr is modified to refer to the character "count" bytes before + * srcPtr, or to the first character in the TkText if there aren't + * "count" bytes earlier than srcPtr. + * + * Side effects: + * None. + * + *--------------------------------------------------------------------------- */ void -TkTextIndexBackChars(srcPtr, count, dstPtr) - TkTextIndex *srcPtr; /* Source index. */ - int count; /* How many characters backward to - * move. May be negative. */ - TkTextIndex *dstPtr; /* Destination index: gets modified. */ +TkTextIndexBackBytes(srcPtr, byteCount, dstPtr) + CONST TkTextIndex *srcPtr; /* Source index. */ + int byteCount; /* How many bytes backward to move. May be + * negative. */ + TkTextIndex *dstPtr; /* Destination index: gets modified. */ { TkTextSegment *segPtr; int lineIndex; - if (count < 0) { - TkTextIndexForwChars(srcPtr, -count, dstPtr); + if (byteCount < 0) { + TkTextIndexForwBytes(srcPtr, -byteCount, dstPtr); return; } *dstPtr = *srcPtr; - dstPtr->charIndex -= count; + dstPtr->byteIndex -= byteCount; lineIndex = -1; - while (dstPtr->charIndex < 0) { + while (dstPtr->byteIndex < 0) { /* * Move back one line in the text. If we run off the beginning * of the file then just return the first character in the text. @@ -702,7 +932,7 @@ TkTextIndexBackChars(srcPtr, count, dstPtr) lineIndex = TkBTreeLineIndex(dstPtr->linePtr); } if (lineIndex == 0) { - dstPtr->charIndex = 0; + dstPtr->byteIndex = 0; return; } lineIndex--; @@ -714,8 +944,124 @@ TkTextIndexBackChars(srcPtr, count, dstPtr) for (segPtr = dstPtr->linePtr->segPtr; segPtr != NULL; segPtr = segPtr->nextPtr) { - dstPtr->charIndex += segPtr->size; + dstPtr->byteIndex += segPtr->size; + } + } +} + +/* + *--------------------------------------------------------------------------- + * + * TkTextIndexBackChars -- + * + * Given an index for a text widget, this procedure creates a new + * index that points "count" characters earlier than the source index. + * + * Results: + * *dstPtr is modified to refer to the character "count" characters + * before srcPtr, or to the first character in the file if there + * aren't "count" characters earlier than srcPtr. + * + * Side effects: + * None. + * + *--------------------------------------------------------------------------- + */ + +void +TkTextIndexBackChars(srcPtr, charCount, dstPtr) + CONST TkTextIndex *srcPtr; /* Source index. */ + int charCount; /* How many characters backward to move. + * May be negative. */ + TkTextIndex *dstPtr; /* Destination index: gets modified. */ +{ + TkTextSegment *segPtr, *oldPtr; + int lineIndex, segSize; + char *p, *start, *end; + + if (charCount <= 0) { + TkTextIndexForwChars(srcPtr, -charCount, dstPtr); + return; + } + + *dstPtr = *srcPtr; + + /* + * Find offset within seg that contains byteIndex. + * Move backward specified number of chars. + */ + + lineIndex = -1; + + segSize = dstPtr->byteIndex; + for (segPtr = dstPtr->linePtr->segPtr; ; segPtr = segPtr->nextPtr) { + if (segSize <= segPtr->size) { + break; + } + segSize -= segPtr->size; + } + while (1) { + if (segPtr->typePtr == &tkTextCharType) { + start = segPtr->body.chars; + end = segPtr->body.chars + segSize; + for (p = end; ; p = Tcl_UtfPrev(p, start)) { + if (charCount == 0) { + dstPtr->byteIndex -= (end - p); + return; + } + if (p == start) { + break; + } + charCount--; + } + } else { + if (charCount <= segSize) { + dstPtr->byteIndex -= charCount; + return; + } + charCount -= segSize; + } + dstPtr->byteIndex -= segSize; + + /* + * Move back into previous segment. + */ + + oldPtr = segPtr; + segPtr = dstPtr->linePtr->segPtr; + if (segPtr != oldPtr) { + for ( ; segPtr->nextPtr != oldPtr; segPtr = segPtr->nextPtr) { + /* Empty body. */ + } + segSize = segPtr->size; + continue; + } + + /* + * Move back to previous line. + */ + + if (lineIndex < 0) { + lineIndex = TkBTreeLineIndex(dstPtr->linePtr); + } + if (lineIndex == 0) { + dstPtr->byteIndex = 0; + return; + } + lineIndex--; + dstPtr->linePtr = TkBTreeFindLine(dstPtr->tree, lineIndex); + + /* + * Compute the length of the line and add that to dstPtr->byteIndex. + */ + + oldPtr = dstPtr->linePtr->segPtr; + for (segPtr = oldPtr; segPtr != NULL; segPtr = segPtr->nextPtr) { + dstPtr->byteIndex += segPtr->size; + oldPtr = segPtr; } + segPtr = oldPtr; + segSize = segPtr->size; } } @@ -762,15 +1108,15 @@ StartEnd(string, indexPtr) length = p-string; if ((*string == 'l') && (strncmp(string, "lineend", length) == 0) && (length >= 5)) { - indexPtr->charIndex = 0; + indexPtr->byteIndex = 0; for (segPtr = indexPtr->linePtr->segPtr; segPtr != NULL; segPtr = segPtr->nextPtr) { - indexPtr->charIndex += segPtr->size; + indexPtr->byteIndex += segPtr->size; } - indexPtr->charIndex -= 1; + indexPtr->byteIndex -= sizeof(char); } else if ((*string == 'l') && (strncmp(string, "linestart", length) == 0) && (length >= 5)) { - indexPtr->charIndex = 0; + indexPtr->byteIndex = 0; } else if ((*string == 'w') && (strncmp(string, "wordend", length) == 0) && (length >= 5)) { int firstChar = 1; @@ -791,7 +1137,7 @@ StartEnd(string, indexPtr) firstChar = 0; } offset += 1; - indexPtr->charIndex += 1; + indexPtr->byteIndex += sizeof(char); if (offset >= segPtr->size) { segPtr = TkTextIndexToSeg(indexPtr, &offset); } @@ -820,10 +1166,10 @@ StartEnd(string, indexPtr) firstChar = 0; } offset -= 1; - indexPtr->charIndex -= 1; + indexPtr->byteIndex -= sizeof(char); if (offset < 0) { - if (indexPtr->charIndex < 0) { - indexPtr->charIndex = 0; + if (indexPtr->byteIndex < 0) { + indexPtr->byteIndex = 0; goto done; } segPtr = TkTextIndexToSeg(indexPtr, &offset); |