stk/Tk/unix/tkUnixFont.c

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1998-04-10 06:59:06 -04:00
/*
* tkUnixFont.c --
*
* Contains the Unix implementation of the platform-independant
* font package interface.
*
* Copyright (c) 1996 Sun Microsystems, Inc.
*
* See the file "license.terms" for information on usage and redistribution
* of this file, and for a DISCLAIMER OF ALL WARRANTIES.
*
* SCCS: @(#) tkUnixFont.c 1.15 97/05/19 13:48:45
*/
#include "tkPort.h"
#include "tkInt.h"
#include "tkUnixInt.h"
#include "tkFont.h"
#ifndef ABS
#define ABS(n) (((n) < 0) ? -(n) : (n))
#endif
/*
* The following structure represents Unix's implementation of a font.
*/
typedef struct UnixFont {
TkFont font; /* Stuff used by generic font package. Must
* be first in structure. */
Display *display; /* The display to which font belongs. */
XFontStruct *fontStructPtr; /* X information about font. */
char types[256]; /* Array giving types of all characters in
* the font, used when displaying control
* characters. See below for definition. */
int widths[256]; /* Array giving widths of all possible
* characters in the font. */
int underlinePos; /* Offset from baseline to origin of
* underline bar (used for simulating a native
* underlined font). */
int barHeight; /* Height of underline or overstrike bar
* (used for simulating a native underlined or
* strikeout font). */
} UnixFont;
/*
* Possible values for entries in the "types" field in a UnixFont structure,
* which classifies the types of all characters in the given font. This
* information is used when measuring and displaying characters.
*
* NORMAL: Standard character.
* REPLACE: This character doesn't print: instead of
* displaying character, display a replacement
* sequence like "\n" (for those characters where
* ANSI C defines such a sequence) or a sequence
* of the form "\xdd" where dd is the hex equivalent
* of the character.
* SKIP: Don't display anything for this character. This
* is only used where the font doesn't contain
* all the characters needed to generate
* replacement sequences.
*/
#define NORMAL 0
#define REPLACE 1
#define SKIP 2
/*
* Characters used when displaying control sequences.
*/
static char hexChars[] = "0123456789abcdefxtnvr\\";
/*
* The following table maps some control characters to sequences like '\n'
* rather than '\x10'. A zero entry in the table means no such mapping
* exists, and the table only maps characters less than 0x10.
*/
static char mapChars[] = {
0, 0, 0, 0, 0, 0, 0,
'a', 'b', 't', 'n', 'v', 'f', 'r',
0
};
static UnixFont * AllocFont _ANSI_ARGS_((TkFont *tkFontPtr,
Tk_Window tkwin, XFontStruct *fontStructPtr,
CONST char *fontName));
static void DrawChars _ANSI_ARGS_((Display *display,
Drawable drawable, GC gc, UnixFont *fontPtr,
CONST char *source, int numChars, int x,
int y));
static int GetControlCharSubst _ANSI_ARGS_((int c, char buf[4]));
/*
*---------------------------------------------------------------------------
*
* TkpGetNativeFont --
*
* Map a platform-specific native font name to a TkFont.
*
* Results:
* The return value is a pointer to a TkFont that represents the
* native font. If a native font by the given name could not be
* found, the return value is NULL.
*
* Every call to this procedure returns a new TkFont structure,
* even if the name has already been seen before. The caller should
* call TkpDeleteFont() when the font is no longer needed.
*
* The caller is responsible for initializing the memory associated
* with the generic TkFont when this function returns and releasing
* the contents of the generic TkFont before calling TkpDeleteFont().
*
* Side effects:
* None.
*
*---------------------------------------------------------------------------
*/
TkFont *
TkpGetNativeFont(tkwin, name)
Tk_Window tkwin; /* For display where font will be used. */
CONST char *name; /* Platform-specific font name. */
{
XFontStruct *fontStructPtr;
fontStructPtr = XLoadQueryFont(Tk_Display(tkwin), name);
if (fontStructPtr == NULL) {
return NULL;
}
return (TkFont *) AllocFont(NULL, tkwin, fontStructPtr, name);
}
/*
*---------------------------------------------------------------------------
*
* TkpGetFontFromAttributes --
*
* Given a desired set of attributes for a font, find a font with
* the closest matching attributes.
*
* Results:
* The return value is a pointer to a TkFont that represents the
* font with the desired attributes. If a font with the desired
* attributes could not be constructed, some other font will be
* substituted automatically.
*
* Every call to this procedure returns a new TkFont structure,
* even if the specified attributes have already been seen before.
* The caller should call TkpDeleteFont() to free the platform-
* specific data when the font is no longer needed.
*
* The caller is responsible for initializing the memory associated
* with the generic TkFont when this function returns and releasing
* the contents of the generic TkFont before calling TkpDeleteFont().
*
* Side effects:
* None.
*
*---------------------------------------------------------------------------
*/
TkFont *
TkpGetFontFromAttributes(tkFontPtr, tkwin, faPtr)
TkFont *tkFontPtr; /* If non-NULL, store the information in
* this existing TkFont structure, rather than
* allocating a new structure to hold the
* font; the existing contents of the font
* will be released. If NULL, a new TkFont
* structure is allocated. */
Tk_Window tkwin; /* For display where font will be used. */
CONST TkFontAttributes *faPtr; /* Set of attributes to match. */
{
int numNames, score, i, scaleable, pixelsize, xaPixelsize;
int bestIdx, bestScore, bestScaleableIdx, bestScaleableScore;
TkXLFDAttributes xa;
char buf[256];
UnixFont *fontPtr;
char **nameList;
XFontStruct *fontStructPtr;
CONST char *fmt, *family;
double d;
family = faPtr->family;
if (family == NULL) {
family = "*";
}
pixelsize = -faPtr->pointsize;
if (pixelsize < 0) {
d = -pixelsize * 25.4 / 72;
d *= WidthOfScreen(Tk_Screen(tkwin));
d /= WidthMMOfScreen(Tk_Screen(tkwin));
d += 0.5;
pixelsize = (int) d;
}
/*
* Replace the standard Windows and Mac family names with the names that
* X likes.
*/
if ((strcasecmp("Times New Roman", family) == 0)
|| (strcasecmp("New York", family) == 0)) {
family = "Times";
} else if ((strcasecmp("Courier New", family) == 0)
|| (strcasecmp("Monaco", family) == 0)) {
family = "Courier";
} else if ((strcasecmp("Arial", family) == 0)
|| (strcasecmp("Geneva", family) == 0)) {
family = "Helvetica";
}
/*
* First try for the Q&D exact match.
*/
#if 0
sprintf(buf, "-*-%.200s-%s-%c-normal-*-*-%d-*-*-*-*-iso8859-1", family,
((faPtr->weight > TK_FW_NORMAL) ? "bold" : "medium"),
((faPtr->slant == TK_FS_ROMAN) ? 'r' :
(faPtr->slant == TK_FS_ITALIC) ? 'i' : 'o'),
faPtr->pointsize * 10);
fontStructPtr = XLoadQueryFont(Tk_Display(tkwin), buf);
#else
fontStructPtr = NULL;
#endif
if (fontStructPtr != NULL) {
goto end;
}
/*
* Couldn't find exact match. Now fall back to other available
* physical fonts.
*/
fmt = "-*-%.240s-*-*-*-*-*-*-*-*-*-*-*-*";
sprintf(buf, fmt, family);
nameList = XListFonts(Tk_Display(tkwin), buf, 10000, &numNames);
if (numNames == 0) {
/*
* Try getting some system font.
*/
sprintf(buf, fmt, "fixed");
nameList = XListFonts(Tk_Display(tkwin), buf, 10000, &numNames);
if (numNames == 0) {
getsystem:
fontStructPtr = XLoadQueryFont(Tk_Display(tkwin), "fixed");
if (fontStructPtr == NULL) {
fontStructPtr = XLoadQueryFont(Tk_Display(tkwin), "*");
if (fontStructPtr == NULL) {
panic("TkpGetFontFromAttributes: cannot get any font");
}
}
goto end;
}
}
/*
* Inspect each of the XLFDs and pick the one that most closely
* matches the desired attributes.
*/
bestIdx = 0;
bestScore = INT_MAX;
bestScaleableIdx = 0;
bestScaleableScore = INT_MAX;
for (i = 0; i < numNames; i++) {
score = 0;
scaleable = 0;
if (TkParseXLFD(nameList[i], &xa) != TCL_OK) {
continue;
}
xaPixelsize = -xa.fa.pointsize;
/*
* Since most people used to use -adobe-* in their XLFDs,
* preserve the preference for "adobe" foundry. Otherwise
* some applications looks may change slightly if another foundry
* is chosen.
*/
if (strcasecmp(xa.foundry, "adobe") != 0) {
score += 3000;
}
if (xa.fa.pointsize == 0) {
/*
* A scaleable font is almost always acceptable, but the
* corresponding bitmapped font would be better.
*/
score += 10;
scaleable = 1;
} else {
/*
* A font that is too small is better than one that is too
* big.
*/
if (xaPixelsize > pixelsize) {
score += (xaPixelsize - pixelsize) * 120;
} else {
score += (pixelsize - xaPixelsize) * 100;
}
}
score += ABS(xa.fa.weight - faPtr->weight) * 30;
score += ABS(xa.fa.slant - faPtr->slant) * 25;
if (xa.slant == TK_FS_OBLIQUE) {
/*
* Italic fonts are preferred over oblique. */
score += 4;
}
if (xa.setwidth != TK_SW_NORMAL) {
/*
* The normal setwidth is highly preferred.
*/
score += 2000;
}
if (xa.charset == TK_CS_OTHER) {
/*
* The standard character set is highly preferred over
* foreign languages charsets (because we don't support
* other languages yet).
*/
score += 11000;
}
if ((xa.charset == TK_CS_NORMAL) && (xa.encoding != 1)) {
/*
* The '1' encoding for the characters above 0x7f is highly
* preferred over the other encodings.
*/
score += 8000;
}
if (scaleable) {
if (score < bestScaleableScore) {
bestScaleableIdx = i;
bestScaleableScore = score;
}
} else {
if (score < bestScore) {
bestIdx = i;
bestScore = score;
}
}
if (score == 0) {
break;
}
}
/*
* Now we know which is the closest matching scaleable font and the
* closest matching bitmapped font. If the scaleable font was a
* better match, try getting the scaleable font; however, if the
* scalable font was not actually available in the desired
* pointsize, fall back to the closest bitmapped font.
*/
fontStructPtr = NULL;
if (bestScaleableScore < bestScore) {
char *str, *rest;
/*
* Fill in the desired pointsize info for this font.
*/
tryscale:
str = nameList[bestScaleableIdx];
for (i = 0; i < XLFD_PIXEL_SIZE - 1; i++) {
str = strchr(str + 1, '-');
}
rest = str;
for (i = XLFD_PIXEL_SIZE - 1; i < XLFD_REGISTRY; i++) {
rest = strchr(rest + 1, '-');
}
*str = '\0';
sprintf(buf, "%.240s-*-%d-*-*-*-*-*%s", nameList[bestScaleableIdx],
pixelsize, rest);
*str = '-';
fontStructPtr = XLoadQueryFont(Tk_Display(tkwin), buf);
bestScaleableScore = INT_MAX;
}
if (fontStructPtr == NULL) {
strcpy(buf, nameList[bestIdx]);
fontStructPtr = XLoadQueryFont(Tk_Display(tkwin), buf);
if (fontStructPtr == NULL) {
/*
* This shouldn't happen because the font name is one of the
* names that X gave us to use, but it does anyhow.
*/
if (bestScaleableScore < INT_MAX) {
goto tryscale;
} else {
XFreeFontNames(nameList);
goto getsystem;
}
}
}
XFreeFontNames(nameList);
end:
fontPtr = AllocFont(tkFontPtr, tkwin, fontStructPtr, buf);
fontPtr->font.fa.underline = faPtr->underline;
fontPtr->font.fa.overstrike = faPtr->overstrike;
return (TkFont *) fontPtr;
}
/*
*---------------------------------------------------------------------------
*
* TkpDeleteFont --
*
* Called to release a font allocated by TkpGetNativeFont() or
* TkpGetFontFromAttributes(). The caller should have already
* released the fields of the TkFont that are used exclusively by
* the generic TkFont code.
*
* Results:
* None.
*
* Side effects:
* TkFont is deallocated.
*
*---------------------------------------------------------------------------
*/
void
TkpDeleteFont(tkFontPtr)
TkFont *tkFontPtr; /* Token of font to be deleted. */
{
UnixFont *fontPtr;
fontPtr = (UnixFont *) tkFontPtr;
XFreeFont(fontPtr->display, fontPtr->fontStructPtr);
ckfree((char *) fontPtr);
}
/*
*---------------------------------------------------------------------------
*
* TkpGetFontFamilies --
*
* Return information about the font families that are available
* on the display of the given window.
*
* Results:
* interp->result is modified to hold a list of all the available
* font families.
*
* Side effects:
* None.
*
*---------------------------------------------------------------------------
*/
void
TkpGetFontFamilies(interp, tkwin)
Tcl_Interp *interp;
Tk_Window tkwin;
{
int i, new, numNames;
char *family, *end, *p;
Tcl_HashTable familyTable;
Tcl_HashEntry *hPtr;
Tcl_HashSearch search;
char **nameList;
Tcl_InitHashTable(&familyTable, TCL_STRING_KEYS);
nameList = XListFonts(Tk_Display(tkwin), "*", 10000, &numNames);
for (i = 0; i < numNames; i++) {
if (nameList[i][0] != '-') {
continue;
}
family = strchr(nameList[i] + 1, '-');
if (family == NULL) {
continue;
}
family++;
end = strchr(family, '-');
if (end == NULL) {
continue;
}
*end = '\0';
for (p = family; *p != '\0'; p++) {
if (isupper(UCHAR(*p))) {
*p = tolower(UCHAR(*p));
}
}
Tcl_CreateHashEntry(&familyTable, family, &new);
}
XFree(nameList);
hPtr = Tcl_FirstHashEntry(&familyTable, &search);
while (hPtr != NULL) {
#ifdef STk_CODE
Tcl_AppendElement(interp,STk_stringify(Tcl_GetHashKey(&familyTable,hPtr),0));
#else
Tcl_AppendElement(interp, Tcl_GetHashKey(&familyTable, hPtr));
#endif
hPtr = Tcl_NextHashEntry(&search);
}
Tcl_DeleteHashTable(&familyTable);
}
/*
*---------------------------------------------------------------------------
*
* Tk_MeasureChars --
*
* Determine the number of characters from the string that will fit
* in the given horizontal span. The measurement is done under the
* assumption that Tk_DrawChars() will be used to actually display
* the characters.
*
* Results:
* The return value is the number of characters from source that
* fit into the span that extends from 0 to maxLength. *lengthPtr is
* filled with the x-coordinate of the right edge of the last
* character that did fit.
*
* Side effects:
* None.
*
*---------------------------------------------------------------------------
*/
int
Tk_MeasureChars(tkfont, source, numChars, maxLength, flags, lengthPtr)
Tk_Font tkfont; /* Font in which characters will be drawn. */
CONST char *source; /* Characters to be displayed. Need not be
* '\0' terminated. */
int numChars; /* Maximum number of characters to consider
* from source string. */
int maxLength; /* If > 0, maxLength specifies the longest
* permissible line length; don't consider any
* character that would cross this
* x-position. If <= 0, then line length is
* unbounded and the flags argument is
* ignored. */
int flags; /* Various flag bits OR-ed together:
* TK_PARTIAL_OK means include the last char
* which only partially fit on this line.
* TK_WHOLE_WORDS means stop on a word
* boundary, if possible.
* TK_AT_LEAST_ONE means return at least one
* character even if no characters fit. */
int *lengthPtr; /* Filled with x-location just after the
* terminating character. */
{
UnixFont *fontPtr;
CONST char *p; /* Current character. */
CONST char *term; /* Pointer to most recent character that
* may legally be a terminating character. */
int termX; /* X-position just after term. */
int curX; /* X-position corresponding to p. */
int newX; /* X-position corresponding to p+1. */
int c, sawNonSpace;
fontPtr = (UnixFont *) tkfont;
if (numChars == 0) {
*lengthPtr = 0;
return 0;
}
if (maxLength <= 0) {
maxLength = INT_MAX;
}
newX = curX = termX = 0;
p = term = source;
sawNonSpace = !isspace(UCHAR(*p));
/*
* Scan the input string one character at a time, calculating width.
*/
for (c = UCHAR(*p); ; ) {
newX += fontPtr->widths[c];
if (newX > maxLength) {
break;
}
curX = newX;
numChars--;
p++;
if (numChars == 0) {
term = p;
termX = curX;
break;
}
c = UCHAR(*p);
if (isspace(c)) {
if (sawNonSpace) {
term = p;
termX = curX;
sawNonSpace = 0;
}
} else {
sawNonSpace = 1;
}
}
/*
* P points to the first character that doesn't fit in the desired
* span. Use the flags to figure out what to return.
*/
if ((flags & TK_PARTIAL_OK) && (numChars > 0) && (curX < maxLength)) {
/*
* Include the first character that didn't quite fit in the desired
* span. The width returned will include the width of that extra
* character.
*/
numChars--;
curX = newX;
p++;
}
if ((flags & TK_AT_LEAST_ONE) && (term == source) && (numChars > 0)) {
term = p;
termX = curX;
if (term == source) {
term++;
termX = newX;
}
} else if ((numChars == 0) || !(flags & TK_WHOLE_WORDS)) {
term = p;
termX = curX;
}
*lengthPtr = termX;
return term-source;
}
/*
*---------------------------------------------------------------------------
*
* Tk_DrawChars, DrawChars --
*
* Draw a string of characters on the screen. Tk_DrawChars()
* expands control characters that occur in the string to \X or
* \xXX sequences. DrawChars() just draws the strings.
*
* Results:
* None.
*
* Side effects:
* Information gets drawn on the screen.
*
*---------------------------------------------------------------------------
*/
void
Tk_DrawChars(display, drawable, gc, tkfont, source, numChars, x, y)
Display *display; /* Display on which to draw. */
Drawable drawable; /* Window or pixmap in which to draw. */
GC gc; /* Graphics context for drawing characters. */
Tk_Font tkfont; /* Font in which characters will be drawn;
* must be the same as font used in GC. */
CONST char *source; /* Characters to be displayed. Need not be
* '\0' terminated. All Tk meta-characters
* (tabs, control characters, and newlines)
* should be stripped out of the string that
* is passed to this function. If they are
* not stripped out, they will be displayed as
* regular printing characters. */
int numChars; /* Number of characters in string. */
int x, y; /* Coordinates at which to place origin of
* string when drawing. */
{
UnixFont *fontPtr;
CONST char *p;
int i, type;
char buf[4];
fontPtr = (UnixFont *) tkfont;
p = source;
for (i = 0; i < numChars; i++) {
type = fontPtr->types[UCHAR(*p)];
if (type != NORMAL) {
DrawChars(display, drawable, gc, fontPtr, source, p - source, x, y);
x += XTextWidth(fontPtr->fontStructPtr, source, p - source);
if (type == REPLACE) {
DrawChars(display, drawable, gc, fontPtr, buf,
GetControlCharSubst(UCHAR(*p), buf), x, y);
x += fontPtr->widths[UCHAR(*p)];
}
source = p + 1;
}
p++;
}
DrawChars(display, drawable, gc, fontPtr, source, p - source, x, y);
}
static void
DrawChars(display, drawable, gc, fontPtr, source, numChars, x, y)
Display *display; /* Display on which to draw. */
Drawable drawable; /* Window or pixmap in which to draw. */
GC gc; /* Graphics context for drawing characters. */
UnixFont *fontPtr; /* Font in which characters will be drawn;
* must be the same as font used in GC. */
CONST char *source; /* Characters to be displayed. Need not be
* '\0' terminated. All Tk meta-characters
* (tabs, control characters, and newlines)
* should be stripped out of the string that
* is passed to this function. If they are
* not stripped out, they will be displayed as
* regular printing characters. */
int numChars; /* Number of characters in string. */
int x, y; /* Coordinates at which to place origin of
* string when drawing. */
{
XDrawString(display, drawable, gc, x, y, source, numChars);
if (fontPtr->font.fa.underline != 0) {
XFillRectangle(display, drawable, gc, x,
y + fontPtr->underlinePos,
(unsigned) XTextWidth(fontPtr->fontStructPtr, source, numChars),
(unsigned) fontPtr->barHeight);
}
if (fontPtr->font.fa.overstrike != 0) {
y -= fontPtr->font.fm.descent + (fontPtr->font.fm.ascent) / 10;
XFillRectangle(display, drawable, gc, x, y,
(unsigned) XTextWidth(fontPtr->fontStructPtr, source, numChars),
(unsigned) fontPtr->barHeight);
}
}
/*
*---------------------------------------------------------------------------
*
* AllocFont --
*
* Helper for TkpGetNativeFont() and TkpGetFontFromAttributes().
* Allocates and intializes the memory for a new TkFont that
* wraps the platform-specific data.
*
* Results:
* Returns pointer to newly constructed TkFont.
*
* The caller is responsible for initializing the fields of the
* TkFont that are used exclusively by the generic TkFont code, and
* for releasing those fields before calling TkpDeleteFont().
*
* Side effects:
* Memory allocated.
*
*---------------------------------------------------------------------------
*/
static UnixFont *
AllocFont(tkFontPtr, tkwin, fontStructPtr, fontName)
TkFont *tkFontPtr; /* If non-NULL, store the information in
* this existing TkFont structure, rather than
* allocating a new structure to hold the
* font; the existing contents of the font
* will be released. If NULL, a new TkFont
* structure is allocated. */
Tk_Window tkwin; /* For display where font will be used. */
XFontStruct *fontStructPtr; /* X information about font. */
CONST char *fontName; /* The string passed to XLoadQueryFont() to
* construct the fontStructPtr. */
{
UnixFont *fontPtr;
unsigned long value;
int i, width, firstChar, lastChar, n, replaceOK;
char *name, *p;
char buf[4];
TkXLFDAttributes xa;
double d;
if (tkFontPtr != NULL) {
fontPtr = (UnixFont *) tkFontPtr;
XFreeFont(fontPtr->display, fontPtr->fontStructPtr);
} else {
fontPtr = (UnixFont *) ckalloc(sizeof(UnixFont));
}
/*
* Encapsulate the generic stuff in the TkFont.
*/
fontPtr->font.fid = fontStructPtr->fid;
if (XGetFontProperty(fontStructPtr, XA_FONT, &value) && (value != 0)) {
name = Tk_GetAtomName(tkwin, (Atom) value);
TkInitFontAttributes(&xa.fa);
if (TkParseXLFD(name, &xa) == TCL_OK) {
goto ok;
}
}
TkInitFontAttributes(&xa.fa);
if (TkParseXLFD(fontName, &xa) != TCL_OK) {
TkInitFontAttributes(&fontPtr->font.fa);
fontPtr->font.fa.family = Tk_GetUid(fontName);
} else {
ok:
fontPtr->font.fa = xa.fa;
}
if (fontPtr->font.fa.pointsize < 0) {
d = -fontPtr->font.fa.pointsize * 72 / 25.4;
d *= WidthMMOfScreen(Tk_Screen(tkwin));
d /= WidthOfScreen(Tk_Screen(tkwin));
d += 0.5;
fontPtr->font.fa.pointsize = (int) d;
}
fontPtr->font.fm.ascent = fontStructPtr->ascent;
fontPtr->font.fm.descent = fontStructPtr->descent;
fontPtr->font.fm.maxWidth = fontStructPtr->max_bounds.width;
fontPtr->font.fm.fixed = 1;
fontPtr->display = Tk_Display(tkwin);
fontPtr->fontStructPtr = fontStructPtr;
/*
* Classify the characters.
*/
firstChar = fontStructPtr->min_char_or_byte2;
lastChar = fontStructPtr->max_char_or_byte2;
for (i = 0; i < 256; i++) {
if ((i == 0177) || (i < firstChar) || (i > lastChar)) {
fontPtr->types[i] = REPLACE;
} else {
fontPtr->types[i] = NORMAL;
}
}
/*
* Compute the widths for all the normal characters. Any other
* characters are given an initial width of 0. Also, this determines
* if this is a fixed or variable width font, by comparing the widths
* of all the normal characters.
*/
width = 0;
for (i = 0; i < 256; i++) {
if (fontPtr->types[i] != NORMAL) {
n = 0;
} else if (fontStructPtr->per_char == NULL) {
n = fontStructPtr->max_bounds.width;
} else {
n = fontStructPtr->per_char[i - firstChar].width;
}
fontPtr->widths[i] = n;
if (n != 0) {
if (width == 0) {
width = n;
} else if (width != n) {
fontPtr->font.fm.fixed = 0;
}
}
}
/*
* Compute the widths of the characters that should be replaced with
* control character expansions. If the appropriate chars are not
* available in this font, then control character expansions will not
* be used; control chars will be invisible & zero-width.
*/
replaceOK = 1;
for (p = hexChars; *p != '\0'; p++) {
if ((UCHAR(*p) < firstChar) || (UCHAR(*p) > lastChar)) {
replaceOK = 0;
break;
}
}
for (i = 0; i < 256; i++) {
if (fontPtr->types[i] == REPLACE) {
if (replaceOK) {
n = GetControlCharSubst(i, buf);
for ( ; --n >= 0; ) {
fontPtr->widths[i] += fontPtr->widths[UCHAR(buf[n])];
}
} else {
fontPtr->types[i] = SKIP;
}
}
}
if (XGetFontProperty(fontStructPtr, XA_UNDERLINE_POSITION, &value)) {
fontPtr->underlinePos = value;
} else {
/*
* If the XA_UNDERLINE_POSITION property does not exist, the X
* manual recommends using the following value:
*/
fontPtr->underlinePos = fontStructPtr->descent / 2;
}
fontPtr->barHeight = 0;
if (XGetFontProperty(fontStructPtr, XA_UNDERLINE_THICKNESS, &value)) {
/*
* Sometimes this is 0 even though it shouldn't be.
*/
fontPtr->barHeight = value;
}
if (fontPtr->barHeight == 0) {
/*
* If the XA_UNDERLINE_THICKNESS property does not exist, the X
* manual recommends using the width of the stem on a capital
* letter. I don't know of a way to get the stem width of a letter,
* so guess and use 1/3 the width of a capital I.
*/
fontPtr->barHeight = fontPtr->widths['I'] / 3;
if (fontPtr->barHeight == 0) {
fontPtr->barHeight = 1;
}
}
if (fontPtr->underlinePos + fontPtr->barHeight > fontStructPtr->descent) {
/*
* If this set of cobbled together values would cause the bottom of
* the underline bar to stick below the descent of the font, jack
* the underline up a bit higher.
*/
fontPtr->barHeight = fontStructPtr->descent - fontPtr->underlinePos;
if (fontPtr->barHeight == 0) {
fontPtr->underlinePos--;
fontPtr->barHeight = 1;
}
}
return fontPtr;
}
/*
*---------------------------------------------------------------------------
*
* GetControlCharSubst --
*
* When displaying text in a widget, a backslashed escape sequence
* is substituted for control characters that occur in the text.
* Given a control character, fill in a buffer with the replacement
* string that should be displayed.
*
* Results:
* The return value is the length of the substitute string. buf is
* filled with the substitute string; it is not '\0' terminated.
*
* Side effects:
* None.
*
*---------------------------------------------------------------------------
*/
static int
GetControlCharSubst(c, buf)
int c; /* The control character to be replaced. */
char buf[4]; /* Buffer that gets replacement string. It
* only needs to be 4 characters long. */
{
buf[0] = '\\';
if ((c < sizeof(mapChars)) && (mapChars[c] != 0)) {
buf[1] = mapChars[c];
return 2;
} else {
buf[1] = 'x';
buf[2] = hexChars[(c >> 4) & 0xf];
buf[3] = hexChars[c & 0xf];
return 4;
}
}