Screenshots:

Linux:Windows_95:

russian.cxx:

#if 0
// Compiling (X11)
 c++ -O5 -I/usr/X11R6/include -L/usr/X11R6/lib \
 russian.cxx -o russian -lX11 -lXext -lfltk;
#endif 

#include <FL/Fl_Window.H>
#include <FL/Fl_Return_Button.H>
#include <FL/Fl_Input.H>
#include <FL/Fl.H>
#include <locale.h>

// exit
void ok_cb(Fl_Widget*, void* v)
{
    ((Fl_Window*)v)->hide();
}

int main(int argc, char* argv[])
{
    Fl_Window w(275, 120, "Russian");
#ifndef WIN32   
    Fl_Input input(5, 25, 265, 40, "÷×ÏÄ:"); // koi8r
#else
    Fl_Input input(5, 25, 265, 40, "Ââîä:"); // cp-1251
#endif
    {
        Fl_Input& o=input;
        o.labeltype(FL_EMBOSSED_LABEL);
        o.labelfont(FL_COURIER);
        o.labelsize(18);
        o.labelcolor(FL_BLUE);
        o.selection_color(FL_GREEN);
        o.textfont(FL_COURIER);
        o.textsize(18);
        o.align(FL_ALIGN_TOP_LEFT);
    }
#ifndef WIN32   
    Fl_Return_Button ok(70, 70, 150, 40, "äÏÂÒÏ"); // koi8r
#else
    Fl_Return_Button ok(70, 70, 150, 40, "Äîáðî"); // cp-1251
#endif
    {
        Fl_Return_Button& o=ok;
        o.labeltype(FL_ENGRAVED_LABEL);
        o.labelfont(FL_TIMES_BOLD);
        o.labelsize(18);
        o.labelcolor(FL_RED);
        o.callback(ok_cb, &w);
    }
    w.end();

// On systems with non-russian default locale you may have to use
// "env LC_ALL=ru_RU.KOI8-R ./russian" or LC_ALL=ru_SU command to
// make russian locale be the default locale of the process
// so that Xkb allows you to input russian.
    setlocale(LC_CTYPE, ""); // default locale.

#ifndef WIN32
    extern const char* fl_encoding;
    fl_encoding="koi8-r"; // russian encoding.
#else

#if 0

// If you want your FLTK programm to run under non-russian windows
// (windows PE,etc.) and use Russian fonts you have to edit file
// fl_font_win32.cxx and change DEFAULT_CHARSET to RUSSIAN_CHARSET
// in CreateFont(); this will force Windows to use Russian(cp1251) fonts. On
// russian systems (with russian default charset) you do not have to do anything.

    fid = CreateFont(
        -size,              // negative makes it use "char size"
        0,                  // logical average character width 
        0,                  // angle of escapement 
        0,                  // base-line orientation angle 
        weight,
        italic,
        FALSE,              // underline attribute flag 
        FALSE,              // strikeout attribute flag 

//      DEFAULT_CHARSET,    // character set identifier 
        RUSSIAN_CHARSET, // REPLACED
        
        OUT_DEFAULT_PRECIS, // output precision 
        CLIP_DEFAULT_PRECIS,// clipping precision 
        DEFAULT_QUALITY,    // output quality 
        DEFAULT_PITCH,      // pitch and family 
        name                // pointer to typeface name string 
    );
#endif

#endif

    Fl::args(argc, argv); // process parameters given in comand-line.
    w.show(argc, argv); // apply -display, etc. parameters to the window.

    return Fl::run();
}