/*
 * tkUnixRFont.c --
 *
 *	Alternate implementation of tkUnixFont.c using Xft.
 *
 * Copyright (c) 2002-2003 Keith Packard
 *
 * See the file "license.terms" for information on usage and redistribution
 * of this file, and for a DISCLAIMER OF ALL WARRANTIES.
 *
 * RCS: @(#) $Id: tkUnixRFont.c,v 1.5 2003/10/29 10:03:32 dkf Exp $
 */

#include "tkUnixInt.h"
#include "tkFont.h"
#include <X11/Xft/Xft.h>
#include <ctype.h>

typedef struct _UnixFtFace {
    XftFont	    *ftFont;
    FcPattern	    *source;
    FcCharSet	    *charset;
} UnixFtFace;

typedef struct _UnixFtFont {
    TkFont	    font;    	/* Stuff used by generic font package.  Must
				 * be first in structure. */
    UnixFtFace	    *faces;
    int		    nfaces;
    FcCharSet	    *charset;
    FcPattern	    *pattern;
    
    Display	    *display;
    int		    screen;
    XftDraw	    *ftDraw;
    Drawable	    drawable;
    XftColor	    color;
} UnixFtFont;

void
TkpFontPkgInit(mainPtr)
    TkMainInfo *mainPtr;	/* The application being created. */
{
}

static XftFont *
GetFont(fontPtr, ucs4)
    UnixFtFont *fontPtr;
    FcChar32 ucs4;
{
    int i;

    if (ucs4) {
	for (i = 0; i < fontPtr->nfaces; i++) {
	    FcCharSet *charset = fontPtr->faces[i].charset;
	    if (charset && FcCharSetHasChar(charset, ucs4)) {
		break;
	    }
	}
	if (i == fontPtr->nfaces) {
	    i = 0;
	}
    } else {
	i = 0;
    }
    if (!fontPtr->faces[i].ftFont) {
	FcPattern *pat = FcFontRenderPrepare(0, fontPtr->pattern,
		fontPtr->faces[i].source);

	fontPtr->faces[i].ftFont = XftFontOpenPattern(fontPtr->display, pat);
    }
    return fontPtr->faces[i].ftFont;
}

/*
 *---------------------------------------------------------------------------
 *
 * InitFont --
 *
 *	Initializes the fields of a UnixFtFont structure.
 *	If fontPtr is NULL, also allocates a new UnixFtFont.
 * 
 * Results:
 * 	On error, frees fontPtr and returns NULL, otherwise
 * 	returns fontPtr.
 *
 *---------------------------------------------------------------------------
 */

static UnixFtFont *
InitFont(tkwin, pattern, fontPtr)
    Tk_Window tkwin;
    FcPattern *pattern;
    UnixFtFont *fontPtr;
{
    TkFontAttributes *faPtr;
    TkFontMetrics *fmPtr;
    char *family;
    int weight, slant, spacing, i;
    double size;
    FcFontSet *set, *charset;
    FcResult result;
    XftFont *ftFont;
    
    if (!fontPtr) {
	fontPtr = (UnixFtFont *) ckalloc(sizeof(UnixFtFont));
    }
    if (!fontPtr) {
	return NULL; /* Never called? */
    }
    
    FcConfigSubstitute(0, pattern, FcMatchPattern);
    XftDefaultSubstitute(Tk_Display(tkwin), Tk_ScreenNumber(tkwin), pattern);

    /*
     * Generate the list of fonts
     */
    set = FcFontSort(0, pattern, FcTrue, &charset, &result);

    if (!set) {
	FcPatternDestroy(pattern);
	ckfree((char *) fontPtr);
	return NULL;
    }

    fontPtr->charset = charset;
    fontPtr->pattern = pattern;
    
    fontPtr->faces = (UnixFtFace *) ckalloc(set->nfont * sizeof(UnixFtFace));
    if (!fontPtr->faces) {
	FcFontSetDestroy(set);
	FcCharSetDestroy(charset);
	FcPatternDestroy(pattern);
	ckfree((char *) fontPtr);
	return NULL;
    }
    fontPtr->nfaces = set->nfont;
    
    /*
     * Fill in information about each returned font
     */
    for (i = 0; i < set->nfont; i++) {
	fontPtr->faces[i].ftFont = 0;
	fontPtr->faces[i].source = set->fonts[i];
	if (FcPatternGetCharSet(set->fonts[i], FC_CHARSET, 0,
		&charset) == FcResultMatch) {
	    fontPtr->faces[i].charset = FcCharSetCopy(charset);
	} else {
	    fontPtr->faces[i].charset = 0;
	}
    }

    fontPtr->font.fid = XLoadFont(Tk_Display(tkwin), "fixed");
    fontPtr->display = Tk_Display(tkwin);
    fontPtr->screen = Tk_ScreenNumber(tkwin);
    fontPtr->ftDraw = 0;
    fontPtr->drawable = 0;
    fontPtr->color.color.red = 0;
    fontPtr->color.color.green = 0;
    fontPtr->color.color.blue = 0;
    fontPtr->color.color.alpha = 0xffff;
    fontPtr->color.pixel = 0xffffffff;

    ftFont = GetFont(fontPtr, 0);

    /*
     * Build the Tk font structure
     */
    if (XftPatternGetString(ftFont->pattern, XFT_FAMILY, 0,
	    &family) != XftResultMatch) {
	family = "Unknown";
    }
    
    if (XftPatternGetInteger(ftFont->pattern, XFT_WEIGHT, 0,
	    &weight) != XftResultMatch) {
	weight = XFT_WEIGHT_MEDIUM;
    }
    if (weight <= XFT_WEIGHT_MEDIUM) {
	weight = TK_FW_NORMAL;
    } else {
	weight = TK_FW_BOLD;
    }
    
    if (XftPatternGetInteger(ftFont->pattern, XFT_SLANT, 0,
	    &slant) != XftResultMatch) {
	slant = XFT_SLANT_ROMAN;
    }
    if (slant <= XFT_SLANT_ROMAN) {
	slant = TK_FS_ROMAN;
    } else {
	slant = TK_FS_ITALIC;
    }
    
    if (XftPatternGetDouble(ftFont->pattern, XFT_SIZE, 0,
	    &size) != XftResultMatch) {
	size = 12.0;
    }
    
    if (XftPatternGetInteger(ftFont->pattern, XFT_SPACING, 0,
	    &spacing) != XftResultMatch) {
	spacing = XFT_PROPORTIONAL;
    }
    if (spacing == XFT_PROPORTIONAL) {
	spacing = 0;
    } else {
	spacing = 1;
    }
#if DEBUG_FONTSEL
    printf("family %s size %g weight %d slant %d\n",
	    family, size, weight, slant);
#endif

    faPtr = &fontPtr->font.fa;
    faPtr->family = family;
    faPtr->size = (int) size;
    faPtr->weight = weight;
    faPtr->slant = slant;
    faPtr->underline = 0;
    faPtr->overstrike = 0;

    fmPtr = &fontPtr->font.fm;
    fmPtr->ascent = ftFont->ascent;
    fmPtr->descent = ftFont->descent;
    fmPtr->maxWidth = ftFont->max_advance_width;
    fmPtr->fixed = spacing;

    return fontPtr;
}

static void
FiniFont(fontPtr)
    UnixFtFont *fontPtr;
{
    Display *display = fontPtr->display;
    Tk_ErrorHandler handler;
    int i;

    handler = Tk_CreateErrorHandler(display, -1, -1, -1,
	    (Tk_ErrorProc *) NULL, (ClientData) NULL);
    for (i = 0; i < fontPtr->nfaces; i++) {
	if (fontPtr->faces[i].ftFont) {
	    XftFontClose(fontPtr->display, fontPtr->faces[i].ftFont);
	}
	if (fontPtr->faces[i].source) {
	    FcPatternDestroy(fontPtr->faces[i].source);
	}
	if (fontPtr->faces[i].charset) {
	    FcCharSetDestroy(fontPtr->faces[i].charset);
	}
    }
    if (fontPtr->ftDraw) {
	XftDrawDestroy(fontPtr->ftDraw);
    }
    if (fontPtr->font.fid) {
	XUnloadFont(fontPtr->display, fontPtr->font.fid);
    }
    Tk_DeleteErrorHandler(handler);
}

TkFont *
TkpGetNativeFont(tkwin, name)
    Tk_Window tkwin;		/* For display where font will be used. */
    CONST char *name;		/* Platform-specific font name. */
{
    UnixFtFont *fontPtr;
    FcPattern *pattern;
#if DEBUG_FONTSEL
    printf("TkpGetNativeFont %s\n", name);
#endif

    pattern = XftXlfdParse(name, FcFalse, FcFalse);
    if (!pattern) {
	return NULL;
    }

    /*
     * Should also try: pattern = FcNameParse(name);
     * but generic/tkFont.c expects TkpGetNativeFont() to only
     * work on XLFD names under Unix.
     */

    fontPtr = InitFont(tkwin, pattern, NULL);
    if (!fontPtr) {
	return NULL;
    }
    return &fontPtr->font;
}

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. */
{
    XftPattern *pattern;
    int weight, slant;
    UnixFtFont *fontPtr;

#if DEBUG_FONTSEL
    printf("TkpGetFontFromAttributes %s-%d %d %d\n", faPtr->family,
	    faPtr->size, faPtr->weight, faPtr->slant);
#endif
    pattern = XftPatternCreate();
    if (faPtr->family) {
	XftPatternAddString(pattern, XFT_FAMILY, faPtr->family);
    }
    if (faPtr->size > 0) {
	XftPatternAddInteger(pattern, XFT_SIZE, faPtr->size);
    } else if (faPtr->size < 0) {
	XftPatternAddInteger(pattern, XFT_PIXEL_SIZE, -faPtr->size);
    } else {
	XftPatternAddInteger(pattern, XFT_SIZE, 12);
    }
    switch (faPtr->weight) {
    case TK_FW_NORMAL:
    default:
	weight = XFT_WEIGHT_MEDIUM;
	break;
    case TK_FW_BOLD:
	weight = XFT_WEIGHT_BOLD;
	break;
    }
    XftPatternAddInteger(pattern, XFT_WEIGHT, weight);
    switch (faPtr->slant) {
    case TK_FS_ROMAN:
    default:
	slant = XFT_SLANT_ROMAN;
	break;
    case TK_FS_ITALIC:
	slant = XFT_SLANT_ITALIC;
	break;
    case TK_FS_OBLIQUE:
	slant = XFT_SLANT_OBLIQUE;
	break;
    }
    XftPatternAddInteger(pattern, XFT_SLANT, slant);

    fontPtr = (UnixFtFont *) tkFontPtr;
    if (fontPtr != NULL) {
	FiniFont(fontPtr);
    }
    fontPtr = InitFont(tkwin, pattern, fontPtr);
    if (!fontPtr) {
	return NULL;
    }
    return &fontPtr->font;
}

void
TkpDeleteFont(tkFontPtr)
    TkFont *tkFontPtr;		/* Token of font to be deleted. */
{
    UnixFtFont *fontPtr = (UnixFtFont *) tkFontPtr;

    FiniFont(fontPtr);
    /* XXX tkUnixFont.c doesn't free tkFontPtr... */
}

/*
 *---------------------------------------------------------------------------
 *
 * TkpGetFontFamilies --
 *
 *	Return information about the font families that are available
 *	on the display of the given window.
 *
 * Results:
 *	Modifies interp's result object to hold a list of all the available
 *	font families.
 *
 *---------------------------------------------------------------------------
 */

void
TkpGetFontFamilies(interp, tkwin)
    Tcl_Interp *interp;		/* Interp to hold result. */
    Tk_Window tkwin;		/* For display to query. */
{
    Tcl_Obj *resultPtr, *strPtr;
    XftFontSet *list;
    int i;
    char *family;

    resultPtr = Tcl_NewListObj(0, NULL);

    list = XftListFonts(Tk_Display(tkwin), Tk_ScreenNumber(tkwin), 0,
	    XFT_FAMILY, 0);
    for (i = 0; i < list->nfont; i++) {
	if (XftPatternGetString(list->fonts[i], XFT_FAMILY, 0,
		&family) == XftResultMatch) {
	    strPtr = Tcl_NewStringObj(Tk_GetUid(family), -1);
	    Tcl_ListObjAppendElement(NULL, resultPtr, strPtr);
	}
    }
    XftFontSetDestroy(list);

    Tcl_SetObjResult(interp, resultPtr);
}

/*
 *-------------------------------------------------------------------------
 *
 * TkpGetSubFonts --
 *	Called by [testfont subfonts] in the Tk testing package.
 *
 * Results:
 *	Sets interp's result to a list of the faces used by tkfont
 *
 *-------------------------------------------------------------------------
 */

void
TkpGetSubFonts(interp, tkfont)
    Tcl_Interp *interp;
    Tk_Font tkfont;
{
    Tcl_Obj *objv[3], *listPtr, *resultPtr;
    UnixFtFont *fontPtr = (UnixFtFont *) tkfont;
    FcPattern *pattern;
    char *family, *foundry, *encoding;
    int i;

    resultPtr = Tcl_NewListObj(0, NULL);

    for (i = 0; i < fontPtr->nfaces ; ++i) {
 	pattern = FcFontRenderPrepare(0, fontPtr->pattern,
		fontPtr->faces[i].source);

	if (XftPatternGetString(pattern, XFT_FAMILY, 0,
		&family) != XftResultMatch) {
	    family = "Unknown";
	}
	if (XftPatternGetString(pattern, XFT_FOUNDRY, 0,
		&foundry) != XftResultMatch) {
	    foundry = "Unknown";
	}
	if (XftPatternGetString(pattern, XFT_ENCODING, 0,
		&encoding) != XftResultMatch) {
	    encoding = "Unknown";
	}
	objv[0] = Tcl_NewStringObj(family, -1);
	objv[1] = Tcl_NewStringObj(foundry, -1);
	objv[2] = Tcl_NewStringObj(encoding, -1);
	listPtr = Tcl_NewListObj(3, objv);
	Tcl_ListObjAppendElement(NULL, resultPtr, listPtr);
    }
    Tcl_SetObjResult(interp, resultPtr);
}

int
Tk_MeasureChars(tkfont, source, numBytes, maxLength, flags, lengthPtr)
    Tk_Font tkfont;		/* Font in which characters will be drawn. */
    CONST char *source;		/* UTF-8 string to be displayed.  Need not be
				 * '\0' terminated. */
    int numBytes;		/* Maximum number of bytes to consider
				 * from source string. */
    int maxLength;		/* If >= 0, maxLength specifies the longest
				 * permissible line length in pixels; 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. */
{
    UnixFtFont *fontPtr = (UnixFtFont *) tkfont;
    XftFont *ftFont;
    FcChar32 c;
    int clen;
    XGlyphInfo extents;
    int curX, newX;
    int termByte = 0, termX = 0;
    int curByte, newByte, sawNonSpace;
#if 0
    char string[256];
    int len = 0;
#endif
    
    curX = 0;
    curByte = 0;
    sawNonSpace = 0;
    while (numBytes > 0) {
	clen = FcUtf8ToUcs4((FcChar8 *) source, &c, numBytes);

	if (clen <= 0) {
	    /*
	     * This should not happen, but it can, due to bugs in Tcl
	     * (i.e., [encoding convertfrom identity]).
	     */
	    *lengthPtr = curX;
	    return ++curByte;
	}

	source += clen;
	numBytes -= clen;
	if (c < 256 && isspace(c)) {		/* I18N: ??? */
	    if (sawNonSpace) {
		termByte = curByte;
		termX = curX;
		sawNonSpace = 0;
	    }
	} else {
	    sawNonSpace = 1;
	}

#if 0
	string[len++] = (char) c;
#endif
	ftFont = GetFont(fontPtr, c);

	XftTextExtents32(fontPtr->display, ftFont, &c, 1, &extents);

	newX = curX + extents.xOff;
	newByte = curByte + clen;
	if (maxLength >= 0 && newX > maxLength) {
	    if (flags & TK_PARTIAL_OK ||
		    (flags & TK_AT_LEAST_ONE && curByte == 0)) {
		curX = newX;
		curByte = newByte;
	    } else if (flags & TK_WHOLE_WORDS && termX != 0) {
		curX = termX;
		curByte = termByte;
	    }
	    break;
	}

	curX = newX;
	curByte = newByte;
    }
#if 0
    string[len] = '\0';
    printf("MeasureChars %s length %d bytes %d\n", string, curX, curByte);
#endif
    *lengthPtr = curX;
    return curByte;
}

#define NUM_SPEC    1024

void
Tk_DrawChars(display, drawable, gc, tkfont, source, numBytes, 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;		/* UTF-8 string 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 numBytes;		/* Number of bytes in string. */
    int x, y;			/* Coordinates at which to place origin of
				 * string when drawing. */
{
    UnixFtFont *fontPtr = (UnixFtFont *) tkfont;
    XGCValues values;
    XColor xcolor;
    int clen;
    XftGlyphFontSpec specs[NUM_SPEC];
    int nspec;
    XGlyphInfo metrics;

    if (fontPtr->ftDraw == 0) {
#if 0
	printf("Switch to drawable 0x%x\n", drawable);
#endif
	fontPtr->ftDraw = XftDrawCreate(display, drawable,
		DefaultVisual(display, fontPtr->screen),
		DefaultColormap(display, fontPtr->screen));
	fontPtr->drawable = drawable;
    } else {
	Tk_ErrorHandler handler;

        handler = Tk_CreateErrorHandler(display, -1, -1, -1,
		(Tk_ErrorProc *) NULL, (ClientData) NULL);
	XftDrawChange(fontPtr->ftDraw, drawable);
	fontPtr->drawable = drawable;
	Tk_DeleteErrorHandler(handler);
    }
    XGetGCValues(display, gc, GCForeground, &values);
    if (values.foreground != fontPtr->color.pixel) {
	xcolor.pixel = values.foreground;
	XQueryColor(display, DefaultColormap(display, fontPtr->screen),
		&xcolor);
	fontPtr->color.color.red = xcolor.red;
	fontPtr->color.color.green = xcolor.green;
	fontPtr->color.color.blue = xcolor.blue;
	fontPtr->color.color.alpha = 0xffff;
	fontPtr->color.pixel = values.foreground;
    }
    nspec = 0;
    while (numBytes > 0) {
	XftFont *ftFont;
	FcChar32 c;
	
	clen = FcUtf8ToUcs4((FcChar8 *) source, &c, numBytes);
	if (clen <= 0) {
	    /* This should not happen, but it can. */
	    return;
	}
	source += clen;
	numBytes -= clen;

	ftFont = GetFont(fontPtr, c);
	if (ftFont) {
	    specs[nspec].font = ftFont;
	    specs[nspec].glyph = XftCharIndex(fontPtr->display, ftFont, c);
	    specs[nspec].x = x;
	    specs[nspec].y = y;

	    XftGlyphExtents(fontPtr->display, ftFont, &specs[nspec].glyph, 1,
		    &metrics);
	    x += metrics.xOff;
	    y += metrics.yOff;
	    nspec++;
	    if (nspec == NUM_SPEC) {
		XftDrawGlyphFontSpec(fontPtr->ftDraw, &fontPtr->color,
			specs, nspec);
		nspec = 0;
	    }
	}
    }
    if (nspec) {
	XftDrawGlyphFontSpec(fontPtr->ftDraw, &fontPtr->color, specs, nspec);
    }
}