tkunixfont.c

linux系统下的音频通信

	    }
	}
	Tcl_CreateHashEntry(&familyTable, family, &new);
    }

    hPtr = Tcl_FirstHashEntry(&familyTable, &search);
    while (hPtr != NULL) {
	Tcl_AppendElement(interp, Tcl_GetHashKey(&familyTable, hPtr));
	hPtr = Tcl_NextHashEntry(&search);
    }

    Tcl_DeleteHashTable(&familyTable);
    XFreeFontNames(nameList);
}

/*
 *---------------------------------------------------------------------------
 *
 *  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. */
{
    /*
     * Perform a quick sanity check to ensure we won't overflow the X
     * coordinate space.
     */
    
    if ((x + (fontPtr->fontStructPtr->max_bounds.width * numChars) > 0x7fff)) {
	int length;

	/*
	 * The string we are being asked to draw is too big and would overflow
	 * the X coordinate space.  Unfortunatley X servers aren't too bright
	 * and so they won't deal with this case cleanly.  We need to truncate
	 * the string before sending it to X.
	 */

	numChars = Tk_MeasureChars((Tk_Font) fontPtr, source, numChars,
		0x7fff - x, 0, &length);
    }

    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;
    }
}