/* * tkTextIndex.c (CTk) -- * * This module provides procedures that manipulate indices for * text widgets. * * Copyright (c) 1992-1994 The Regents of the University of California. * Copyright (c) 1994-1995 Sun Microsystems, Inc. * * See the file "license.terms" for information on usage and redistribution * of this file, and for a DISCLAIMER OF ALL WARRANTIES. * * @(#) $Id: ctk.shar,v 1.50 1996/01/15 14:47:16 andrewm Exp andrewm $ */ #include "default.h" #include "tkPort.h" #include "tkInt.h" #include "tkText.h" /* * Index to use to select last character in line (very large integer): */ #define LAST_CHAR 1000000 /* * Forward declarations for procedures defined later in this file: */ static char * ForwBack _ANSI_ARGS_((char *string, TkTextIndex *indexPtr)); static char * StartEnd _ANSI_ARGS_(( char *string, TkTextIndex *indexPtr)); /* *-------------------------------------------------------------- * * TkTextMakeIndex -- * * 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 * TkTextMakeIndex(tree, lineIndex, charIndex, indexPtr) TkTextBTree tree; /* Tree that lineIndex and charIndex refer * to. */ int lineIndex; /* Index of desired line (0 means first * line of text). */ int charIndex; /* Index of desired character. */ TkTextIndex *indexPtr; /* Structure to fill in. */ { register TkTextSegment *segPtr; int index; indexPtr->tree = tree; if (lineIndex < 0) { lineIndex = 0; charIndex = 0; } if (charIndex < 0) { charIndex = 0; } indexPtr->linePtr = TkBTreeFindLine(tree, lineIndex); if (indexPtr->linePtr == NULL) { indexPtr->linePtr = TkBTreeFindLine(tree, TkBTreeNumLines(tree)); charIndex = 0; } /* * Verify that the index is within the range of the line. * If not, just use the index of the last character in the line. */ for (index = 0, segPtr = indexPtr->linePtr->segPtr; ; segPtr = segPtr->nextPtr) { if (segPtr == NULL) { indexPtr->charIndex = index-1; break; } index += segPtr->size; if (index > charIndex) { indexPtr->charIndex = charIndex; break; } } return indexPtr; } /* *-------------------------------------------------------------- * * TkTextIndexToSeg -- * * 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. * * 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. */ { register TkTextSegment *segPtr; int offset; for (offset = indexPtr->charIndex, segPtr = indexPtr->linePtr->segPtr; offset >= segPtr->size; offset -= segPtr->size, segPtr = segPtr->nextPtr) { /* Empty loop body. */ } if (offsetPtr != NULL) { *offsetPtr = offset; } return segPtr; } /* *-------------------------------------------------------------- * * TkTextSegToOffset -- * * 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. * * Side effects: * None. * *-------------------------------------------------------------- */ int TkTextSegToOffset(segPtr, linePtr) TkTextSegment *segPtr; /* Segment whose offset is desired. */ TkTextLine *linePtr; /* Line containing segPtr. */ { TkTextSegment *segPtr2; int offset; offset = 0; for (segPtr2 = linePtr->segPtr; segPtr2 != segPtr; segPtr2 = segPtr2->nextPtr) { offset += segPtr2->size; } return offset; } /* *---------------------------------------------------------------------- * * TkTextGetIndex -- * * Given a string, return the line and character indices that * it describes. * * 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. * * Side effects: * None. * *---------------------------------------------------------------------- */ int TkTextGetIndex(interp, textPtr, string, indexPtr) Tcl_Interp *interp; /* Use this for error reporting. */ TkText *textPtr; /* Information about text widget. */ char *string; /* Textual description of position. */ TkTextIndex *indexPtr; /* Index structure to fill in. */ { register char *p; char *end, *endOfBase; Tcl_HashEntry *hPtr; TkTextTag *tagPtr; TkTextSearch search; TkTextIndex first, last; int wantLast, result; char c; /* *--------------------------------------------------------------------- * Stage 1: check to see if the index consists of nothing but a mar * name. We do this check now even though it's also done later, in * order to allow mark names that include funny characters such as * spaces or "+1c". *--------------------------------------------------------------------- */ if (TkTextMarkNameToIndex(textPtr, string, indexPtr) == TCL_OK) { return TCL_OK; } /* *------------------------------------------------ * Stage 2: start again by parsing the base index. *------------------------------------------------ */ indexPtr->tree = textPtr->tree; /* * First look for the form "tag.first" or "tag.last" where "tag" * is the name of a valid tag. Try to use up as much as possible * of the string in this check (strrchr instead of strchr below). * Doing the check now, and in this way, allows tag names to include * funny characters like "@" or "+1c". */ p = strrchr(string, '.'); if (p != NULL) { if ((p[1] == 'f') && (strncmp(p+1, "first", 5) == 0)) { wantLast = 0; endOfBase = p+6; } else if ((p[1] == 'l') && (strncmp(p+1, "last", 4) == 0)) { wantLast = 1; endOfBase = p+5; } else { goto tryxy; } *p = 0; hPtr = Tcl_FindHashEntry(&textPtr->tagTable, string); *p = '.'; if (hPtr == NULL) { goto tryxy; } tagPtr = (TkTextTag *) Tcl_GetHashValue(hPtr); TkTextMakeIndex(textPtr->tree, 0, 0, &first); TkTextMakeIndex(textPtr->tree, TkBTreeNumLines(textPtr->tree), 0, &last); TkBTreeStartSearch(&first, &last, tagPtr, &search); if (!TkBTreeCharTagged(&first, tagPtr) && !TkBTreeNextTag(&search)) { Tcl_AppendResult(interp, "text doesn't contain any characters tagged with \"", Tcl_GetHashKey(&textPtr->tagTable, hPtr), "\"", (char *) NULL); return TCL_ERROR; } *indexPtr = search.curIndex; if (wantLast) { while (TkBTreeNextTag(&search)) { *indexPtr = search.curIndex; } } goto gotBase; } tryxy: if (string[0] == '@') { /* * Find character at a given x,y location in the window. */ int x, y; p = string+1; x = strtol(p, &end, 0); if ((end == p) || (*end != ',')) { goto error; } p = end+1; y = strtol(p, &end, 0); if (end == p) { goto error; } TkTextPixelIndex(textPtr, x, y, indexPtr); endOfBase = end; goto gotBase; } if (isdigit(UCHAR(string[0])) || (string[0] == '-')) { int lineIndex, charIndex; /* * Base is identified with line and character indices. */ lineIndex = strtol(string, &end, 0) - 1; if ((end == string) || (*end != '.')) { goto error; } p = end+1; if ((*p == 'e') && (strncmp(p, "end", 3) == 0)) { charIndex = LAST_CHAR; endOfBase = p+3; } else { charIndex = strtol(p, &end, 0); if (end == p) { goto error; } endOfBase = end; } TkTextMakeIndex(textPtr->tree, lineIndex, charIndex, indexPtr); goto gotBase; } for (p = string; *p != 0; p++) { if (isspace(UCHAR(*p)) || (*p == '+') || (*p == '-')) { break; } } endOfBase = p; #if 0 if (string[0] == '.') { /* * See if the base position is the name of an embedded window. */ c = *endOfBase; *endOfBase = 0; result = TkTextWindowIndex(textPtr, string, indexPtr); *endOfBase = c; if (result != 0) { goto gotBase; } } #endif if ((string[0] == 'e') && (strncmp(string, "end", (size_t) (endOfBase-string)) == 0)) { /* * Base position is end of text. */ TkTextMakeIndex(textPtr->tree, TkBTreeNumLines(textPtr->tree), 0, indexPtr); goto gotBase; } else { /* * See if the base position is the name of a mark. */ c = *endOfBase; *endOfBase = 0; result = TkTextMarkNameToIndex(textPtr, string, indexPtr); *endOfBase = c; if (result == TCL_OK) { goto gotBase; } } goto error; /* *------------------------------------------------------------------- * Stage 3: process zero or more modifiers. Each modifier is either * a keyword like "wordend" or "linestart", or it has the form * "op count units" where op is + or -, count is a number, and units * is "chars" or "lines". *------------------------------------------------------------------- */ gotBase: p = endOfBase; while (1) { while (isspace(UCHAR(*p))) { p++; } if (*p == 0) { break; } if ((*p == '+') || (*p == '-')) { p = ForwBack(p, indexPtr); } else { p = StartEnd(p, indexPtr); } if (p == NULL) { goto error; } } return TCL_OK; error: Tcl_AppendResult(interp, "bad text index \"", string, "\"", (char *) NULL); return TCL_ERROR; } /* *---------------------------------------------------------------------- * * TkTextPrintIndex -- * * * This procedure generates a string description of an index, * suitable for reading in again later. * * Results: * The characters pointed to by string are modified. * * Side effects: * None. * *---------------------------------------------------------------------- */ void TkTextPrintIndex(indexPtr, string) TkTextIndex *indexPtr; /* Pointer to index. */ char *string; /* Place to store the position. Must have * at least TK_POS_CHARS characters. */ { sprintf(string, "%d.%d", TkBTreeLineIndex(indexPtr->linePtr) + 1, indexPtr->charIndex); } /* *-------------------------------------------------------------- * * TkTextIndexCmp -- * * 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. * * Side effects: * None. * *-------------------------------------------------------------- */ int TkTextIndexCmp(index1Ptr, index2Ptr) TkTextIndex *index1Ptr; /* First index. */ TkTextIndex *index2Ptr; /* Second index. */ { int line1, line2; if (index1Ptr->linePtr == index2Ptr->linePtr) { if (index1Ptr->charIndex < index2Ptr->charIndex) { return -1; } else if (index1Ptr->charIndex > index2Ptr->charIndex) { return 1; } else { return 0; } } line1 = TkBTreeLineIndex(index1Ptr->linePtr); line2 = TkBTreeLineIndex(index2Ptr->linePtr); if (line1 < line2) { return -1; } if (line1 > line2) { return 1; } return 0; } /* *---------------------------------------------------------------------- * * ForwBack -- * * 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. * * Side effects: * None. * *---------------------------------------------------------------------- */ static char * ForwBack(string, indexPtr) char *string; /* String to parse for additional info * about modifier (count and units). * Points to "+" or "-" that starts * modifier. */ TkTextIndex *indexPtr; /* Index to update as specified in string. */ { register char *p; char *end, *units; int count, lineIndex; size_t length; /* * Get the count (how many units forward or backward). */ p = string+1; while (isspace(UCHAR(*p))) { p++; } count = strtol(p, &end, 0); if (end == p) { return NULL; } p = end; while (isspace(UCHAR(*p))) { p++; } /* * Find the end of this modifier (next space or + or - character), * then parse the unit specifier and update the position * accordingly. */ units = p; while ((*p != 0) && !isspace(UCHAR(*p)) && (*p != '+') && (*p != '-')) { p++; } length = p - units; if ((*units == 'c') && (strncmp(units, "chars", length) == 0)) { if (*string == '+') { TkTextIndexForwChars(indexPtr, count, indexPtr); } else { TkTextIndexBackChars(indexPtr, count, indexPtr); } } else if ((*units == 'l') && (strncmp(units, "lines", length) == 0)) { lineIndex = TkBTreeLineIndex(indexPtr->linePtr); if (*string == '+') { lineIndex += count; } else { lineIndex -= count; /* * The check below retains the character position, even * if the line runs off the start of the file. Without * it, the character position will get reset to 0 by * TkTextMakeIndex. */ if (lineIndex < 0) { lineIndex = 0; } } TkTextMakeIndex(indexPtr->tree, lineIndex, indexPtr->charIndex, indexPtr); } else { return NULL; } return p; } /* *---------------------------------------------------------------------- * * TkTextIndexForwChars -- * * 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 * after srcPtr, or to the last character in the file if there aren't * "count" characters left in the file. * * 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. */ { TkTextLine *linePtr; TkTextSegment *segPtr; int lineLength; if (count < 0) { TkTextIndexBackChars(srcPtr, -count, dstPtr); return; } *dstPtr = *srcPtr; dstPtr->charIndex += count; while (1) { /* * Compute the length of the current line. */ lineLength = 0; for (segPtr = dstPtr->linePtr->segPtr; segPtr != NULL; segPtr = segPtr->nextPtr) { lineLength += segPtr->size; } /* * If the new index is in the same line then we're done. * Otherwise go on to the next line. */ if (dstPtr->charIndex < lineLength) { return; } dstPtr->charIndex -= lineLength; linePtr = TkBTreeNextLine(dstPtr->linePtr); if (linePtr == NULL) { dstPtr->charIndex = lineLength - 1; return; } dstPtr->linePtr = linePtr; } } /* *---------------------------------------------------------------------- * * 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, count, dstPtr) TkTextIndex *srcPtr; /* Source index. */ int count; /* How many characters backward to * move. May be negative. */ TkTextIndex *dstPtr; /* Destination index: gets modified. */ { TkTextSegment *segPtr; int lineIndex; if (count < 0) { TkTextIndexForwChars(srcPtr, -count, dstPtr); return; } *dstPtr = *srcPtr; dstPtr->charIndex -= count; lineIndex = -1; while (dstPtr->charIndex < 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. */ if (lineIndex < 0) { lineIndex = TkBTreeLineIndex(dstPtr->linePtr); } if (lineIndex == 0) { dstPtr->charIndex = 0; return; } lineIndex--; dstPtr->linePtr = TkBTreeFindLine(dstPtr->tree, lineIndex); /* * Compute the length of the line and add that to dstPtr->charIndex. */ for (segPtr = dstPtr->linePtr->segPtr; segPtr != NULL; segPtr = segPtr->nextPtr) { dstPtr->charIndex += segPtr->size; } } } /* *---------------------------------------------------------------------- * * StartEnd -- * * This procedure handles modifiers like "wordstart" and "lineend" * to adjust indices forwards or backwards. * * Results: * If the modifier 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 * StartEnd(string, indexPtr) char *string; /* String to parse for additional info * about modifier (count and units). * Points to first character of modifer * word. */ TkTextIndex *indexPtr; /* Index to mdoify based on string. */ { char *p; int c, offset; size_t length; register TkTextSegment *segPtr; /* * Find the end of the modifier word. */ for (p = string; isalnum(UCHAR(*p)); p++) { /* Empty loop body. */ } length = p-string; if ((*string == 'l') && (strncmp(string, "lineend", length) == 0) && (length >= 5)) { indexPtr->charIndex = 0; for (segPtr = indexPtr->linePtr->segPtr; segPtr != NULL; segPtr = segPtr->nextPtr) { indexPtr->charIndex += segPtr->size; } indexPtr->charIndex -= 1; } else if ((*string == 'l') && (strncmp(string, "linestart", length) == 0) && (length >= 5)) { indexPtr->charIndex = 0; } else if ((*string == 'w') && (strncmp(string, "wordend", length) == 0) && (length >= 5)) { int firstChar = 1; /* * If the current character isn't part of a word then just move * forward one character. Otherwise move forward until finding * a character that isn't part of a word and stop there. */ segPtr = TkTextIndexToSeg(indexPtr, &offset); while (1) { if (segPtr->typePtr == &tkTextCharType) { c = segPtr->body.chars[offset]; if (!isalnum(UCHAR(c)) && (c != '_')) { break; } firstChar = 0; } offset += 1; indexPtr->charIndex += 1; if (offset >= segPtr->size) { segPtr = TkTextIndexToSeg(indexPtr, &offset); } } if (firstChar) { TkTextIndexForwChars(indexPtr, 1, indexPtr); } } else if ((*string == 'w') && (strncmp(string, "wordstart", length) == 0) && (length >= 5)) { int firstChar = 1; /* * Starting with the current character, look for one that's not * part of a word and keep moving backward until you find one. * Then if the character found wasn't the first one, move forward * again one position. */ segPtr = TkTextIndexToSeg(indexPtr, &offset); while (1) { if (segPtr->typePtr == &tkTextCharType) { c = segPtr->body.chars[offset]; if (!isalnum(UCHAR(c)) && (c != '_')) { break; } firstChar = 0; } offset -= 1; indexPtr->charIndex -= 1; if (offset < 0) { if (indexPtr->charIndex < 0) { indexPtr->charIndex = 0; goto done; } segPtr = TkTextIndexToSeg(indexPtr, &offset); } } if (!firstChar) { TkTextIndexForwChars(indexPtr, 1, indexPtr); } } else { return NULL; } done: return p; }