C++ fltk — 5 — libsigcplusplus
Date: 2023-03-20Last modified: 2024-02-26
Table of contents
#include <FL/Fl.H>
#include <FL/Fl_Box.H>
#include <FL/Fl_Button.H>
#include <FL/Fl_Window.H>
#include <FL/fl_ask.H>
#include <sigc++/sigc++.h>
#include <iostream>
static sigc::signal<void()> SignalClickMe;
static sigc::signal<void()> SignalIncrement;
class WindowTest : public Fl_Window {
int counter = 0;
bool button1_clicked = false;
Fl_Button* button1;
Fl_Button* button2;
Fl_Box* label;
void onClickMe() {
std::cout << "onClickMe()" << std::endl;
if (button1_clicked) {
fl_alert("Stop it, you've clicked me already!");
} else {
button1->label("Thank you!");
button1_clicked = true;
}
}
public:
WindowTest() : Fl_Window(300, 300, 300, 200, "Lambda & Signals") {
button1 = new Fl_Button(5, 5, 80, 25, "Click me");
button2 = new Fl_Button(5, 70, 80, 25, "Increment");
label = new Fl_Box(5, 100, 80, 25, "Counter: 0");
button1->callback([]([[maybe_unused]] Fl_Widget* w,
[[maybe_unused]] void* u) { SignalClickMe.emit(); });
button2->callback([]([[maybe_unused]] Fl_Widget* w,
[[maybe_unused]] void* u) { SignalIncrement.emit(); });
SignalClickMe.connect(sigc::mem_fun(*this, &WindowTest::onClickMe));
SignalIncrement.connect([this] {
char text[50];
sprintf(text, "Counter: %d", ++counter);
label->copy_label(text);
std::cout << "Lamda incremment called " << counter << std::endl;
});
}
};
int main([[maybe_unused]] int argc, [[maybe_unused]] char** argv) {
WindowTest* window = new WindowTest();
window->show(0, NULL);
return Fl::run();
}
Possible output
onClickMe()
onClickMe()
Lamda incremment called 1
Lamda incremment called 2
Lamda incremment called 3