/*
 *  This file is part of the XForms library package.
 *
 *  XForms is free software; you can redistribute it and/or modify it
 *  under the terms of the GNU Lesser General Public License as
 *  published by the Free Software Foundation; either version 2.1, or
 *  (at your option) any later version.
 *
 *  XForms is distributed in the hope that it will be useful, but
 *  WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 *  Lesser General Public License for more details.
 *
 *  You should have received a copy of the GNU Lesser General Public License
 *  along with XForms.  If not, see <http://www.gnu.org/licenses/>.
 */


/**
 * \file fonts.c
 *
 *  This file is part of the XForms library package.
 *  Copyright (c) 1996-2002  T.C. Zhao and Mark Overmars
 *  All rights reserved.
 *
 * All font and string size query routines. There are rooms for speed ups.
 * For one, font switching can be reduced somewhat.
 *
 */

#ifdef HAVE_CONFIG_H
#include "config.h"
#endif

#include "include/forms.h"
#include "flinternal.h"
#include "private/flvasprintf.h"
#include <string.h>
#include <ctype.h>

static XFontStruct * defaultfs;

static XFontStruct * try_get_font_struct( int,
                                          int,
                                          int );
static char * get_fname( const char *,
                         int );


/*
 * Question marks indicate the sizes in tenth of a point. It will be
 * replaced on the fly by the font requesting routines. Depending on
 * the availability of the fonts and capabilities of the server, the
 * font may or may not be scalable.
 *
 * Resolution field is left blank on purpose as the resolution reported
 * by the server is not reliable thus the program can't force the
 * resolution. This way the admins can set the proper font path.
 *
 * Order is important as it has to agree with FL_TIMES_STYLE etc
 * defined in Basic.h
 *
 */

static const char *fnts[ FL_MAXFONTS ] =
{
    "-*-helvetica-medium-r-*-*-*-?-*-*-p-*-*-*",
    "-*-helvetica-bold-r-*-*-*-?-*-*-p-*-*-*",
    "-*-helvetica-medium-o-*-*-*-?-*-*-p-*-*-*",
    "-*-helvetica-bold-o-*-*-*-?-*-*-p-*-*-*",

    "-*-courier-medium-r-*-*-*-?-*-*-*-*-*-*",
    "-*-courier-bold-r-*-*-*-?-*-*-*-*-*-*",
    "-*-courier-medium-o-*-*-*-?-*-*-*-*-*-*",
    "-*-courier-bold-o-*-*-*-?-*-*-*-*-*-*",

    "-*-times-medium-r-*-*-*-?-*-*-p-*-*-*",
    "-*-times-bold-r-*-*-*-?-*-*-p-*-*-*",
    "-*-times-medium-i-*-*-*-?-*-*-p-*-*-*",
    "-*-times-bold-i-*-*-*-?-*-*-p-*-*-*",

    "-*-charter-medium-r-*-*-*-?-*-*-*-*-*-*",
    "-*-charter-bold-r-*-*-*-?-*-*-*-*-*-*",
    "-*-charter-medium-i-*-*-*-?-*-*-*-*-*-*",
    "-*-charter-bold-i-*-*-*-?-*-*-*-*-*-*",
};

static FL_FONT fl_fonts[ FL_MAXFONTS ];

static const char *cv_fname( const char * );

#define DEFAULTF1  "fixed"
#define DEFAULTF2  "6x13"


/***************************************
 * Global initialization routine. Must be called before any font
 * routine can be used. We can place fli_init_font in all font switching
 * and string size query routines so a seperate initialization is not
 * needed, and it has the added bonus that startup *may* be faster,
 * but we pay a function call overhead in every call to any of these
 * font related routines.
 ***************************************/

void
fli_init_font( void )
{
    FL_FONT *flf = fl_fonts;
    const char *const *f = fnts;
    static int initialized;

    if ( initialized )
        return;

    initialized = 1;

    /* If fl_set_font_name() is called before fl_initialize(), we need to
       keep the change */

    for ( ; *f; f++, flf++ )
        if ( ! *flf->fname )
            strcpy( flf->fname, *f );

    /* Load a default font */

    if (    ! defaultfs
         && ! ( defaultfs = XLoadQueryFont( flx->display, DEFAULTF1 ) ) )
        defaultfs = XLoadQueryFont( flx->display, DEFAULTF2 );

    /* Load a couple of fonts at normal size to prevent the caching code from
       using bad looking replacement if strange sizes are requested */

    fl_get_font_struct( FL_NORMAL_STYLE, FL_DEFAULT_SIZE );
    fl_get_font_struct( FL_BOLD_STYLE,   FL_DEFAULT_SIZE );
    fl_get_font_struct( FL_FIXED_STYLE,  FL_DEFAULT_SIZE );
}


/***************************************
 * In addition to get the font handle, we also make the font current
 * in default GC
 ***************************************/

void
fl_set_font( int numb,
             int size )
{
    int dh;
    XCharStruct overall;
    XFontStruct *fs;

    fs = fl_get_font_struct( numb, size );

    /* cur_font is always the one in current GC */

    if ( fl_state[ fl_vmode ].cur_fnt == fs )
    {
#if FL_DEBUG >= ML_DEBUG
        M_debug( "fl_set_font", "current", fli_curfnt );
#endif
        return;
    }

    fl_state[ fl_vmode ].cur_fnt = flx->fs = fs;

    /* Basic font info (no need to send a string, we just want the maximum
       ascent and descent) */

    XTextExtents( flx->fs, "", 0, &dh, &flx->fasc, &flx->fdesc, &overall );
    flx->fheight = flx->fasc + flx->fdesc;

    XSetFont( flx->display, flx->textgc, flx->fs->fid );

    if ( fli_cntl.debug > 1 )
    {
        unsigned long res = 0;

        if ( XGetFontProperty( flx->fs, XA_RESOLUTION, &res ) )
            M_info2( "fl_set_font", "FontResolution: %lu", res );
    }
}


/***************************************
 * Add a new font (indexed by n) or change an existing font.
 * Preferably the font name constains a '?' in the size
 * position so different sizes can be used.
 ***************************************/

int
fl_set_font_name( int          n,
                  const char * name )
{
    FL_FONT *flf;

    if ( n < 0 || n >= FL_MAXFONTS )
    {
        M_warn( "fl_set_font_name", "Bad font number (%d)", n );
        return -1;
    }

    if ( ! name || ! *name )
    {
        M_warn( "fl_set_font_name", "Bad font name" );
        return -1;
    }

    if ( strlen( name ) > FL_MAX_FONTNAME_LENGTH )
    {
        M_warn( "fl_set_font_name", "Font name too long" );
        return -1;
    }

    flf = fl_fonts + n;

    if ( *flf->fname )
    {
        int i;

        for ( i = 0; i < flf->nsize; i++ )
            XFreeFont( flx->display, flf->fs[ i ] );
        *flf->fname = '\0';
    }

    flf->nsize = 0;
    strcpy( flf->fname, name );

    if ( ! flx || ! flx->display )
        return 1;

    return try_get_font_struct( n, FL_DEFAULT_SIZE, 1 ) ? 0 : -1;
}


/***************************************
 * Add a new font (indexed by n) or change an existing font.
 ***************************************/

int
fl_set_font_name_f( int          n,
                    const char * fmt,
                    ... )
{
    char *buf;
    int ret;

    EXPAND_FORMAT_STRING( buf, fmt );
    ret = fl_set_font_name( n, buf );
    fl_free( buf );
    return ret;
}


/***************************************
 * List built-in fonts
 ***************************************/

int
fl_enumerate_fonts( void ( * output )( const char *s ),
                    int  shortform )
{
    FL_FONT *flf = fl_fonts,
            *fe  = flf + FL_MAXFONTS;
    int n = 0;

    for ( ; output && flf < fe; flf++ )
        if ( *flf->fname )
        {
            output( shortform ? cv_fname( flf->fname ) : flf->fname );
            n++;
        }

    return n;
}


/***************************************
 * All font changes go through this routine. If with_fail is false,
 * this routine will not fail even if requested font can't be loaded.
 * A substitution will be made.
 ***************************************/

static XFontStruct *
try_get_font_struct( int numb,
                     int size,
                     int with_fail )
{
    FL_FONT *flf = fl_fonts;
    XFontStruct *fs = NULL;
    int n = 0,
        i;

    if ( special_style( numb ) )
        numb %= FL_SHADOW_STYLE;

    flf = fl_fonts + numb;

    if ( numb < 0 || numb >= FL_MAXFONTS || ! *flf->fname )
    {
        if ( ! fli_no_connection ) {

            /* This function is typically used to test whether a font is
               loadable or not, so it's not a fatal error if it fails. Issue
               a message for information therefore. */

            M_info( "try_get_font_struct", "Bad FontStyle requested: %d: %s",
                    numb, flf->fname );
        }

        if ( ! fl_state[ fl_vmode ].cur_fnt )
            M_warn( "try_get_font_struct", "bad font returned" );

        return fl_state[ fl_vmode ].cur_fnt;
    }

    strcpy( fli_curfnt, get_fname( flf->fname, size ) );

    /* Search for requested size */

    for ( fs = NULL, i = 0; i < flf->nsize; i++ )
        if ( size == flf->size[ i ] )
        {
            fs = flf->fs[ i ];
#if FL_DEBUG >= ML_DEBUG
            M_debug( "try_get_font_struct", "Cache hit: %s",
                     fl_cur_fontname );
#endif
        }

    /* If requested font is not found or cache is full, get the destination
       cache for this size */

    if ( ! fs && flf->nsize == FL_MAX_FONTSIZES )
    {
        XFreeFont( flx->display, flf->fs[ FL_MAX_FONTSIZES - 1 ] );
        flf->nsize--;
    }

    /* Font is not cached, try to load it */

    if ( ! fs )
    {
        n = flf->nsize;
        flf->fs[ n ] = XLoadQueryFont( flx->display, fli_curfnt );

        if ( ( fs = flf->fs[ n ] ) )
        {
            flf->size[ n ] = size;
            flf->nsize++;
        }
    }

    if ( ! fs && with_fail )
        return NULL;

    /* Didn't get it. Try to find a substitute */

    if ( ! fs )
    {
        int mdiff = 1000,
            k = -1;

        M_warn( "try_get_font_struct", "Can't load %s", fli_curfnt );

        /* Search for a replacement */

        for ( i = 0; i < flf->nsize; i++ )
        {
            if ( mdiff > FL_abs( size - flf->size[ i ] ) )
            {
                mdiff = FL_abs( size - flf->size[ i ] );
                k = i;
            }
        }

        fs = k == -1 ? ( flx->fs ? flx->fs : defaultfs ) : flf->fs[ k ];

        /* If we did not get it this time, we won't get it next time either,
           so replace it with whatever we found  */

        flf->size[ flf->nsize ] = size;
        flf->fs[ flf->nsize ] = fs;
        flf->nsize++;
    }

    /* Here we are guranteed a valid font handle although there is no
       gurantee the font handle corresponds to the font requested */

    return fs;
}


/***************************************
 ***************************************/

XFontStruct *
fl_get_font_struct( int style,
                    int size )
{
    return try_get_font_struct( style, size, 0 );
}


/***************************************
 * Similar to fl_get_string_xxxGC except that there is no side effects.
 * Must not free the fontstruct as structure FL_FONT caches the
 * structure for possible future use.
 ***************************************/

int
fl_get_string_width( int          style,
                     int          size,
                     const char * s,
                     int          len )
{
    XFontStruct *fs = fl_get_font_struct( style, size );

    return fli_no_connection ? ( len * size ) : XTextWidth( fs, s, len );
}


/***************************************
 ***************************************/

int
fli_get_string_widthTABfs( XFontStruct * fs,
                           const char *  s,
                           int           len )
{
    int w,
        tab;
    const char *p,
               *q;

    if ( fli_no_connection )
        return 12 * len;

    tab = fli_get_tabpixels( fs );

    for ( w = 0, q = s; *q && ( p = strchr( q, '\t' ) ) && ( p - s ) < len;
          q = p + 1 )
    {
        w += XTextWidth( fs, q, p - q );
        w = ( ( w / tab ) + 1 ) * tab;
    }

    return w += XTextWidth( fs, q, len - ( q - s ) );
}


/***************************************
 ***************************************/

int
fl_get_string_widthTAB( int          style,
                        int          size,
                        const char * s,
                        int          len )
{
    XFontStruct *fs = fl_get_font_struct( style, size );

    return fli_get_string_widthTABfs( fs, s, len );
}


/***************************************
 * Function returns the height of the string, calculated from adding the
 * largest ascent and descent of all its characters in the string, via 'asc'
 * and 'desc' (but which both can be NULL pointers), the maximum ascent
 * and descent.
 ***************************************/

int
fl_get_string_height( int          style,
                      int          size,
                      const char * s,
                      int          len,
                      int *        asc,
                      int *        desc )
{
    int a, d;

    if ( fli_no_connection )
        a = d = size / 2;
    else
    {
        XFontStruct *fs = fl_get_font_struct( style, size );
        XCharStruct overall;
        int dh;

        XTextExtents( fs, s, len, &dh, &a, &d, &overall );
    }

    if ( asc )
        *asc = a;
    if ( desc )
        *desc = d;

    return a + d;
}


/***************************************
 * Returns font height and, via 'asc' and 'desc' (but which both can be NULL
 * pointers), the fonts ascent and descent.
 ***************************************/

int
fl_get_char_height( int   style,
                    int   size,
                    int * asc,
                    int * desc )
{
    int a, d;

    if ( fli_no_connection )
        a = d = size / 2;
    else
    {
        XFontStruct *fs = fl_get_font_struct( style, size );

        a = fs->ascent;
        d = fs->descent;

        if ( asc )
            *asc = a;
        if ( desc )
            *desc = d;
    }

    return a + d;
}


/***************************************
 * Function returns the width of the widest character in the requested font
 ***************************************/

int
fl_get_char_width( int style,
                   int size )
{
    XFontStruct *fs = fl_get_font_struct( style, size );

    return fs->max_bounds.width;
}


/***************************************
 ***************************************/

void
fl_get_string_dimension( int          fntstyle,
                         int          fntsize,
                         const char * s,
                         int          len,
                         int *        width,
                         int *        height )
{
    const char *p,
               *q;
    int h,
        maxw = 0,
        maxh = 0;

    h = fl_get_char_height( fntstyle, fntsize, NULL, NULL );

    for ( q = s; *q && ( p = strchr( q, '\n' ) ); q = p + 1 )
    {
        maxw = FL_max( maxw,
                       fl_get_string_width( fntstyle, fntsize, q, p - q ) );
        maxh += h;
    }

    maxw = FL_max( maxw, fl_get_string_width( fntstyle, fntsize,
                                              q, len - ( q - s ) ) );
    maxh += h;

    *width  = maxw;
    *height = maxh;
}


/*
 * Tab handling. Currently only one tab
 */

#define  MaxTabs   5

static char *tabstop[ MaxTabs ] = { "aaaaaaaa", 0 };
static int tabstopNchar[ MaxTabs ] = { 7 };


/***************************************
 ***************************************/

void
fl_set_tabstop( const char *s )
{
    static int set;

    if ( s )
    {
        if ( set )
            fl_free( *tabstop );
        *tabstop = fl_strdup( s );
        *tabstopNchar = strlen( *tabstop );
        set = 1;
    }
}


/***************************************
 ***************************************/

int
fli_get_tabpixels( XFontStruct * fs )
{
    return   XTextWidth( fs, *tabstop, *tabstopNchar )
           + XTextWidth( fs, " ", 1 );
}


/***************************************
 * Convert X font names to more conventional names by stripping the
 * auxiliary info.
 ***************************************/

static const char *
cv_fname( const char *f )
{
    static char fname[ FL_MAX_FONTNAME_LENGTH + 1 ];
    char *q,
         *p;

    /* Remove all the garbages from head */

    for ( q = strcpy( fname, f ); *q && ! isalnum( ( unsigned char ) *q ); q++ )
        /* empty */ ;

    /* Remove all the garbage from the end, starting from '?' */

    if ( ( p = strchr( fname, '?' ) ) )
        *--p = '\0';

    /* Remove all remaining garbages */

    for ( p = fname + strlen( fname ) - 1;
          p > q && ! isalnum( ( unsigned char ) *p ); p-- )
        /* empty */ ;

    *++p = '\0';

    return q;
}


/***************************************
 * Given a font name and a size (in points), assemble the complete name
 ***************************************/

static char *
get_fname( const char * str,
           int          size )
{
    static char fname[ sizeof fli_curfnt ];
    char len_str[ 50 ];    /* should be enough for all ints */
    char *p;

    /* If necessary truncate font names that are too long, the caller
       expects a real string */

    strncpy( fname, str, sizeof fname - 1 );
    fname[ sizeof fname - 1 ] = '\0';

    if ( ( p = strchr( fname, '?' ) ) )
    {
        int len = sprintf( len_str, "%d0", size );

        if ( len + strlen( str ) <= sizeof fname - 1 )
        {
            memmove( p + len, p + 1, strlen( p ) );
            strncpy( p, len_str, len );
        }
    }

    return fname;
}


/***************************************
 * Some compatibility stuff, i.e. functions that were never documented
 * and were removed from V0.89, but apparently this broke some applications
 * that were using them. Put back in 10/22/00.
 ***************************************/

int
fl_fdesc_( void )
{
    return flx->fdesc;
}


/***************************************
 ***************************************/

int
fl_fheight_( void )
{
    return flx->fheight;
}


/***************************************
 ***************************************/

GC
fl_gc_( void )
{
    return flx->gc;
}


/***************************************
 ***************************************/

GC
fl_textgc_( void )
{
    return flx->textgc;
}


/***************************************
 ***************************************/

Window
fl_cur_win_( void )
{
    return flx->win;
}


/***************************************
 ***************************************/

XFontStruct *
fl_cur_fs_( void )
{
    return flx->fs;
}


/***************************************
 ***************************************/

Display *
fl_display_( void )
{
    return flx->display;
}


/*
 * Local variables:
 * tab-width: 4
 * indent-tabs-mode: nil
 * End:
 */