C++ fltk — 1 — Old style C callback
Date: 2021-08-04Last modified: 2024-02-26
Table of contents
#include <FL/Fl.H>
#include <FL/Fl_Button.H>
#include <FL/Fl_Window.H>
#include <iostream>
// Old style C callback
void cb(Fl_Widget *b, void *data) {
std::cout << "Callback called" << std::endl;
auto win = static_cast<Fl_Window *>(data);
win->label("After click old style");
}
int main([[maybe_unused]] int argc, [[maybe_unused]] char **argv) {
Fl::scheme("gtk+");
auto win = new Fl_Window(100, 100, 400, 300);
auto but = new Fl_Button(160, 200, 80, 40, "Click me");
win->label("Before click");
win->end();
win->show();
but->callback(cb, win);
return Fl::run();
}
Possible output
Callback called
Callback called
Callback called