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//
// Numeric keypad demo program for the Fast Light Tool Kit (FLTK).
//
// Copyright 1998-2024 by Bill Spitzak and others.
//
// This library is free software. Distribution and use rights are outlined in
// the file "COPYING" which should have been included with this file. If this
// file is missing or damaged, see the license at:
//
// https://www.fltk.org/COPYING.php
//
// Please see the following page on how to report bugs and issues:
//
// https://www.fltk.org/bugs.php
//
//
// Demonstrate keyboard remapping: Force number pad to type numbers even if NumLock off
//
// DESCRIPTION
// -----------
// This demonstrates several important things:
//
// o How to use the global event dispatcher function Fl::event_dispatch()
//
// o How to remap keyboard events
//
// o How to use Fl::event_original_key() to easily ensure the dual purpose
// numeric keypad keys generate only numbers even if NumLock is off,
// without affecting the dedicated Home/End/etc keys.
//
// Use of Fl::event_original_key() ensures someone hitting e.g. "7/Home" key
// returns FL_KP+'7', and not FL_Home, while allowing the dedicated "Home" key
// to still generate FL_Home. This allows users to use the "Home" and "End"
// keys to navigate the buffer, while "7/Home" and "1/End" always type numbers.
//
// This demo based on fltk.general thread entitled "keyboard mapping", Aug 2019.
//
#include <FL/Fl.H>
#include <FL/Fl_Double_Window.H>
#include <FL/Fl_Input.H>
#include <FL/Fl_Check_Button.H>
Fl_Check_Button *G_checkbut = 0;
// Global event handler: FLTK calls this after event translation. It's up to us
// to call Fl::handle_(e,w) to actually deliver the event to the widgets. If we
// don't and just return, the event will be dropped. See docs for more.
int MyHandler(int e, Fl_Window *w) {
// Remapping disabled? Early exit..
if (G_checkbut->value() == 0)
return Fl::handle_(e, w);
// Keyboard key pressed? See if we should remap..
if (e == FL_KEYDOWN || e == FL_KEYUP) {
// Get FLTK keycode /before/ NumLock state is applied (see above DESCRIPTION)
int keycode = Fl::event_original_key(); // get keycode before FLTK applies NumLock
if (keycode >= FL_KP && keycode <= FL_KP_Last) { // keypad key pressed?
static char buf[2]; // static: we don't want buffer to go out of scope
buf[0] = char(keycode - FL_KP); // convert keypad keycode -> ascii
buf[1] = 0; // terminate string (for safety)
Fl::e_text = buf; // point to our static buffer
Fl::e_length = 1; // only first char relevant
Fl::e_keysym = keycode; // note: some input widgets require this too
}
}
return Fl::handle_(e, w); // let FLTK deliver event to widgets
}
int main(int argc, char *argv[]) {
Fl_Double_Window *win = new Fl_Double_Window(400, 150, "Keyboard Translation Test");
win->begin();
{
new Fl_Input(100, 10, 200, 25, "Input:");
G_checkbut = new Fl_Check_Button(100, 40, 280, 25, "Force numeric keypad to type numbers");
G_checkbut->labelsize(12);
G_checkbut->set();
}
win->end();
win->resizable(win);
win->show(argc, argv);
win->tooltip("Turn NumLock OFF, then type into Input:\nusing numeric keypad to test translation");
// Set up our event handler to manage events
Fl::event_dispatch(MyHandler);
return(Fl::run());
}
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