path: root/e-util/e-font.c

#define _E_FONT_C_

/*
 * e-font
 *
 * Temporary wrappers around GdkFonts to get unicode displaying
 *
 * Author: Lauris Kaplinski <lauris@helixcode.com>
 *
 * Copyright (C) 2000 Helix Code, Inc.
 *
 * TODO: LRU Cache
 *
 */

#include <string.h>
#include <gdk/gdkx.h>
#include <unicode.h>
#include "e-font.h"

#define FONT_TESTING

struct _EFont {
    gint refcount;
    GdkFont *font;
    GdkFont *bold;
    gboolean twobyte;
    unicode_iconv_t to;
    unicode_iconv_t from;
};

static gchar *find_best_bold (gchar **namelist, gint length, gchar *weight);

EFont *
e_font_from_gdk_name (const gchar *name)
{
    EFont * font;
    GdkFont *gdkfont;

    gdkfont = gdk_font_load (name);
    font = e_font_from_gdk_font (gdkfont);
    gdk_font_unref (gdkfont);

    return font;
}

EFont *
e_font_from_gdk_font (GdkFont *gdkfont)
{
    EFont *font;
    XFontStruct *xfs;
    Atom font_atom, atom;
    Bool status;
    GdkFont *boldfont;

    boldfont = NULL;

    gdk_font_ref (gdkfont);

    /* Try to find iso-10646-1 encoded font with same name */

    font_atom = gdk_atom_intern ("FONT", FALSE);
    if (gdkfont->type == GDK_FONT_FONTSET) {
        XFontStruct **font_structs;
        gint num_fonts;
        gchar **font_names;
        num_fonts = XFontsOfFontSet (GDK_FONT_XFONT (gdkfont),
                         &font_structs,
                         &font_names);
        status = XGetFontProperty (font_structs[0],
                       font_atom,
                       &atom);
    } else {
        status = XGetFontProperty (GDK_FONT_XFONT (gdkfont),
                       font_atom,
                       &atom);
    }
    if (status) {
        gchar *c[14];
        gchar *name, *p;
        gchar *enc, *boldname;
        gchar **namelist;
        GdkFont *newfont;
        gint numfonts, len, i;

        name = gdk_atom_name (atom);
        len = strlen (name) + 64; /* Hope that's sufficent */
        p = name;

        for (i = 0; i < 13; i++) {
            c[i] = p;
            /* Skip text */
            while (*p && (*p != '-')) p++;
            /* Replace hyphen with '\0' */
            if (*p) *p++ = '\0';
        }
        c[i] = p;

        p = alloca (len);

        /* Compose name for unicode encoding */
        enc = "iso10646-1";
        g_snprintf (p, len, "%s-%s-%s-%s-%s-%s-%s-%s-%s-%s-%s-%s-%s-%s",
                c[0], c[1], c[2], c[3], c[4], c[5], c[6], c[7],
                c[8], c[9], c[10], c[11], c[12], enc);
        /* Try to load unicode font */
        newfont = gdk_font_load (p);
        if (newfont) {
            /* OK, use that */
            gdk_font_unref (gdkfont);
            gdkfont = newfont;
        } else {
            /* Nope, use original encoding */
            enc = c[13];
        }
        /* Try to find bolder variant */
        g_snprintf (p, len, "%s-%s-%s-%s-%s-%s-%s-%s-%s-%s-%s-%s-%s-%s",
                c[0], c[1], c[2], "*", c[4], c[5], "*", "*",
                c[8], c[9], c[10], c[11], "*", enc);
        namelist = XListFonts (GDK_FONT_XDISPLAY (gdkfont),
                       p, 32, &numfonts);
        boldname = find_best_bold (namelist, numfonts, c[3]);
        if (boldname) {
            g_snprintf (p, len, "%s-%s-%s-%s-%s-%s-%s-%s-%s-%s-%s-%s-%s-%s",
                    c[0], c[1], c[2], boldname, c[4], c[5], "*", "*",
                    c[8], c[9], c[10], c[11], "*", enc);
            boldfont = gdk_font_load (p);
        }
        XFreeFontNames (namelist);

        g_free (name);
    }

    font = g_new (EFont, 1);

    xfs = GDK_FONT_XFONT (gdkfont);

    font->refcount = 1;
    font->font = gdkfont;
    font->bold = boldfont;
    font->twobyte = ((xfs->min_byte1 != 0) || (xfs->max_byte1 != 0));
    font->to = e_uiconv_to_gdk_font (font->font);
    font->from = e_uiconv_from_gdk_font (font->font);

    return font;

}

void
e_font_ref (EFont *font)
{
    font->refcount++;
}

void
e_font_unref (EFont *font)
{
    font->refcount--;

    if (font->refcount < 1) {
        gdk_font_unref (font->font);
        if (font->bold) gdk_font_unref (font->bold);
        g_free (font);
    }
}

gint
e_font_ascent (EFont * font)
{
    return font->font->ascent;
}

gint
e_font_descent (EFont * font)
{
    return font->font->descent;
}

static gint
e_font_to_native (EFont *font, gchar *native, gchar *utf, gint bytes)
{
    char *ib, *ob;
    size_t ibl, obl;

    ib = utf;
    ibl = bytes;
    ob = native;
    obl = bytes * 4;

    while (ibl > 0) {
        unicode_iconv (font->to, (const char **) &ib, &ibl, &ob, &obl);
        if (ibl > 0) {
            gint len;
            if ((*ib & 0x80) == 0x00) len = 1;
            else if ((*ib &0xe0) == 0xc0) len = 2;
            else if ((*ib &0xf0) == 0xe0) len = 3;
            else if ((*ib &0xf80) == 0xf0) len = 4;
            else {
                g_warning ("Invalid UTF-8 sequence");
                return ob - native;
            }
            ib += len;
            ibl = bytes - (ib - utf);
            if (ibl > bytes) ibl = 0;
            if (!font->twobyte) {
                *ob++ = '_';
                obl--;
            } else {
                *((guint16 *) ob) = '_';
                ob += 2;
                obl -= 2;
            }
        }
    }

    return ob - native;
}

void
e_font_draw_utf8_text (GdkDrawable *drawable, EFont *font, EFontStyle style, GdkGC *gc, gint x, gint y, gchar *text, gint numbytes)
{
    gchar *native;
    gint native_bytes;

    g_return_if_fail (drawable != NULL);
    g_return_if_fail (font != NULL);
    g_return_if_fail (gc != NULL);
    g_return_if_fail (text != NULL);

    if (numbytes < 1) return;

    native = alloca (numbytes * 4);

    native_bytes = e_font_to_native (font, native, text, numbytes);

    if ((style & E_FONT_BOLD) && (font->bold)) {
        gdk_draw_text (drawable, font->bold, gc, x, y, native, native_bytes);
    } else {
        gdk_draw_text (drawable, font->font, gc, x, y, native, native_bytes);
        if (style & E_FONT_BOLD)
            gdk_draw_text (drawable, font->font, gc, x + 1, y, native, native_bytes);
    }
}

gint
e_font_utf8_text_width (EFont *font, EFontStyle style, char *text, int numbytes)
{
    gchar *native;
    gint native_bytes;
    gint width;

    g_return_val_if_fail (font != NULL, 0);
    g_return_val_if_fail (text != NULL, 0);

    if (numbytes < 1) return 0;

    native = alloca (numbytes * 4);

    native_bytes = e_font_to_native (font, native, text, numbytes);

    if ((style & E_FONT_BOLD) && (font->bold)) {
        width = gdk_text_width (font->bold, native, native_bytes);
    } else {
        width = gdk_text_width (font->font, native, native_bytes);
    }

    return width;
}

gint
e_font_utf8_char_width (EFont *font, EFontStyle style, char *text)
{
    gint len;

    g_return_val_if_fail (font != NULL, 0);
    g_return_val_if_fail (text != NULL, 0);

    if ((*text & 0x80) == 0x00) len = 1;
    else if ((*text &0xe0) == 0xc0) len = 2;
    else if ((*text &0xf0) == 0xe0) len = 3;
    else if ((*text &0xf80) == 0xf0) len = 4;
    else {
        g_warning ("Invalid UTF-8 sequence");
        return 0;
    }

    return e_font_utf8_text_width (font, style, text, len);
}

static const gchar *
translate_encoding (const gchar *encoding)
{
    static GHashTable *eh = NULL;
    gchar e[64];

    if (!eh) {
        eh = g_hash_table_new (g_str_hash, g_str_equal);

        g_hash_table_insert (eh, "iso8859-1", "iso-8859-1");
        g_hash_table_insert (eh, "iso8859-2", "iso-8859-2");
        g_hash_table_insert (eh, "iso8859-3", "iso-8859-3");
        g_hash_table_insert (eh, "iso8859-4", "iso-8859-4");
        g_hash_table_insert (eh, "iso8859-5", "iso-8859-5");
        g_hash_table_insert (eh, "iso8859-6", "iso-8859-6");
        g_hash_table_insert (eh, "iso8859-7", "iso-8859-7");
        g_hash_table_insert (eh, "iso8859-8", "iso-8859-8");
        g_hash_table_insert (eh, "iso8859-9", "iso-8859-9");
        g_hash_table_insert (eh, "iso8859-10", "iso-8859-10");
        g_hash_table_insert (eh, "iso8859-13", "iso-8859-13");
        g_hash_table_insert (eh, "iso8859-14", "iso-8859-14");
        g_hash_table_insert (eh, "iso8859-15", "iso-8859-15");
        g_hash_table_insert (eh, "iso10646-1", "UTF-16");
        g_hash_table_insert (eh, "koi8-r", "koi8-r");
    }

    strncpy (e, encoding, 64);
    g_strdown (e);

    return g_hash_table_lookup (eh, e);
}

const gchar *
e_gdk_font_encoding (GdkFont *font)
{
    Atom font_atom, atom;
    Bool status;
    char *name, *p;
    const gchar *encoding;
    gint i;

    if (!font) return NULL;

    font_atom = gdk_atom_intern ("FONT", FALSE);

    if (font->type == GDK_FONT_FONTSET) {
        XFontStruct **font_structs;
        gint num_fonts;
        gchar **font_names;

        num_fonts = XFontsOfFontSet (GDK_FONT_XFONT (font),
                         &font_structs,
                         &font_names);
        status = XGetFontProperty (font_structs[0],
                       font_atom,
                       &atom);
    } else {
        status = XGetFontProperty (GDK_FONT_XFONT (font),
                       font_atom,
                       &atom);
    }

    if (!status) return NULL;

    name = p = gdk_atom_name (atom);

    for (i = 0; i < 13; i++) {
        /* Skip hyphen */
        while (*p && (*p != '-')) p++;
        if (*p) p++;
    }

    if (!*p) return NULL;

    encoding = translate_encoding (p);

    g_free (name);

    return encoding;
}

unicode_iconv_t
e_uiconv_from_gdk_font (GdkFont *font)
{
    static GHashTable *uh = NULL;
    const gchar *enc;
    unicode_iconv_t uiconv;

    if (!font) return (unicode_iconv_t) -1;

    enc = e_gdk_font_encoding (font);

    if (!enc) return (unicode_iconv_t) -1;

    if (!uh) uh = g_hash_table_new (g_str_hash, g_str_equal);

    uiconv = g_hash_table_lookup (uh, enc);

    if (!uiconv) {
        uiconv = unicode_iconv_open ("UTF-8", enc);
        if (uiconv == (unicode_iconv_t) -1) return uiconv;
        g_hash_table_insert (uh, (gpointer) enc, uiconv);
    }

    return uiconv;
}

unicode_iconv_t
e_uiconv_to_gdk_font (GdkFont *font)
{
    static GHashTable *uh = NULL;
    const gchar *enc;
    unicode_iconv_t uiconv;

    if (!font) return (unicode_iconv_t) -1;

    enc = e_gdk_font_encoding (font);

    if (!enc) return (unicode_iconv_t) -1;

    if (!uh) uh = g_hash_table_new (g_str_hash, g_str_equal);

    uiconv = g_hash_table_lookup (uh, enc);

    if (!uiconv) {
        uiconv = unicode_iconv_open (enc, "UTF-8");
        if (uiconv == (unicode_iconv_t) -1) return uiconv;
        g_hash_table_insert (uh, (gpointer) enc, uiconv);
    }

    return uiconv;
}

static gchar *
find_best_bold (gchar **namelist, gint length, gchar *weight)
{
    static GHashTable *wh = NULL;
    gint sw, fw, bw;
    gchar *s, *f, *b;
    gchar *p;
    gint i;

    if (!wh) {
        wh = g_hash_table_new (g_str_hash, g_str_equal);
        g_hash_table_insert (wh, "light", GINT_TO_POINTER (1));
        g_hash_table_insert (wh, "book", GINT_TO_POINTER (2));
        g_hash_table_insert (wh, "regular", GINT_TO_POINTER (2));
        g_hash_table_insert (wh, "medium", GINT_TO_POINTER (3));
        g_hash_table_insert (wh, "demibold", GINT_TO_POINTER (5));
        g_hash_table_insert (wh, "bold", GINT_TO_POINTER (6));
        g_hash_table_insert (wh, "black", GINT_TO_POINTER (8));
    }

    s = alloca (strlen (weight) + 1);
    strcpy (s, weight);
    g_strdown (s);
    sw = GPOINTER_TO_INT (g_hash_table_lookup (wh, s));
    if (sw == 0) return NULL;

    fw = 0; bw = 32;
    f = NULL; b = NULL;

    for (i = 0; i < length; i++) {
        p = namelist[i];
        if (*p) p++;
        while (*p && (*p != '-')) p++;
        if (*p) p++;
        while (*p && (*p != '-')) p++;
        if (*p) p++;
        f = p;
        while (*p && (*p != '-')) p++;
        if (*p) *p = '\0';
        g_strdown (f);
        fw = GPOINTER_TO_INT (g_hash_table_lookup (wh, f));
        if (fw && fw > sw) {
            if (fw - 2 == sw) return namelist[i];
            if (((fw > bw) && (bw == sw + 1)) || ((fw < bw) && (fw - 2 > sw))) {
                bw = fw;
                b = f;
            }
        }
    }

    return b;
}