/*
* 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;
}