//--------------------------------
// fltk_kb.cpp
// version 0001
//--------------------------------

#include <iostream>
#include <string>

#include <FL/Fl.H>
#include <FL/Fl_Window.H>

//############################################################################
class LB_Window : public Fl_Window
{
public:
    LB_Window(int w, int h, const char* title)
        : Fl_Window (w, h, title),
          key       (' '),
          new_key   (false)
    {}
    //------------------------------------------------------------------------
    int handle(int event) override
    {
        if(event == FL_KEYDOWN)
        {
            int e_key = Fl::event_key();
            if(is_special(e_key))
            {
                key     = e_key;
                new_key = true;
                return 1;
            }
            if(Fl::event_length())
            {
//                key     = composed_ascii(e_key, Fl::event_state() & FL_SHIFT);
                key = *(Fl::event_text());
                new_key = true;
                return 1;
            }
        } // end if(event == FL_KEYDOWN)
        return Fl_Window::handle(event);
    }
    //------------------------------------------------------------------------
    int composed_ascii(int _key, bool shifted)
    {
        if(shifted)
        {
            if(_key >= 'a' && _key <= 'z')
                return toupper((char)_key);
            switch(_key)
            {
                case '1':    return '!';
                case '2':    return '@';
                case '3':    return '#';
                case '4':    return '$';
                case '5':    return '%';
                case '6':    return '^';
                case '7':    return '&';
                case '8':    return '*';
                case '9':    return '(';
                case '0':    return ')';
                case '`':    return '~';
                case '-':    return '_';
                case '=':    return '+';
                case '[':    return '{';
                case ']':    return '}';
                case '\\':   return '|';
                case ';':    return ':';
                case '"':    return '"';
                case ',':    return '<';
                case '.':    return '>';
                case '/':    return '?';
            }
        }
        return _key;
    }
    //------------------------------------------------------------------------
    bool is_special(int _key)
    {
        if(    _key == FL_Left
            || _key == FL_Up
            || _key == FL_Right
            || _key == FL_Down
            || _key == FL_BackSpace
            || _key == FL_Tab
            || _key == FL_Enter
            || _key == FL_Escape
            || _key == FL_F
            || _key == FL_Delete
            || (    _key > FL_F
                 && _key < FL_F + 13
               )
          )
            return true;
        return false;
    }
    //------------------------------------------------------------------------
    int  key;
    bool new_key;
};

//############################################################################
int main(int argc, char** argv)
{
    LB_Window    *window = new LB_Window(200, 200, "FLTK KB");
    window->end();
    window->show(argc, argv);
    std::cout << std::endl << std::endl;
    while(window->key != 'x')
    {
        while(!window->new_key)
            Fl::wait();    
        window->new_key = false;
        switch(window->key)
        {
            case FL_Enter:
                std::cout << "ENTER" << std::endl;
                break;
            case FL_Left:
                std::cout << "LEFT_ARROW" << std::endl;
                break;
            case FL_Up:
                std::cout << "UP_ARROW" << std::endl;
                break;
            case FL_Right:
                std::cout << "RIGHT_ARROW" << std::endl;
                break;
            case FL_Down:
                std::cout << "DOWN_ARROW" << std::endl;
                break;
            case FL_F + 1:
            case FL_F + 2:
            case FL_F + 3:
            case FL_F + 4:
            case FL_F + 5:
            case FL_F + 6:
            case FL_F + 7:
            case FL_F + 8:
            case FL_F + 9:
            case FL_F + 10:
            case FL_F + 11:
            case FL_F + 12:
                std::cout << "F" << window->key - FL_F << std::endl;
                break;
            default:
                std::cout << (char) window->key << " : " << window->key << std::endl;
                break;
        }
    }
    return 0;
}

//############################################################################
//////////////////////////////////////////////////////////////////////////////
//############################################################################


/*
FL_BackSpace
FL_Tab
FL_Enter
FL_Pause
FL_Scroll_Lock
FL_Escape
FL_Home
FL_Left
FL_Up
FL_Right
FL_Down
FL_Page_Up
FL_Page_Down
FL_End
FL_Print
FL_Insert
FL_Menu
FL_Num_Lock
FL_KP - One of the keypad numbers; use FL_KP + n for number n.
FL_KP_Enter - The enter key on the keypad.
FL_F - One of the function keys; use FL_F + n for function key n.
FL_Shift_L
FL_Shift_R
FL_Control_L
FL_Control_R
FL_Caps_Lock
FL_Meta_L
FL_Meta_R
FL_Alt_L
FL_Alt_R
FL_Delete


# macOS

time g++ -std=c++17 \
fltk_kb.cpp \
-o fltk_kb_macOS \
-lfltk \
-lfltk_images \
-lfltk_png \
-lfltk_jpeg \
-lfltk_z \
-L/usr/local/lib \
-ljpeg \
-lz \
-lpng \
-framework Cocoa \
-framework CoreGraphics \
-framework CoreFoundation \
-framework ApplicationServices


# msys2

time g++ \
fltk_kb.cpp \
-o fltk_kb.exe \
-std=c++17 \
-O3 \
-Wall \
-Wextra \
-I/path/to/fltk/include \
-L/path/to/fltk/lib \
-lfltk \
-lfltk_images \
-lpthread


# Linux

time g++ \
-std=c++17 \
fltk_kb.cpp \
-o fltk_kb \
-lfltk \
-lfltk_images \
-ljpeg \
-lz 


# piDAC

time g++ \
-std=c++17 \
fltk_kb.cpp \
-o fltk_kb_pi \
-lfltk \
-lfltk_images \
-ljpeg \
-lz \
-lX11 \
-lXcursor \
-lXfixes \
-lXrender \
-lXinerama 

*/