add on_click to buttons

src/Button.cpp

@@ -40,6 +40,9 @@ void Button::on_focus_update(FocusUpdateEvent &event) {
 
 void Button::on_activation_update(ActivationUpdateEvent &event) {
     update_color();
+    if (event.get_activation_status() == false) {
+        on_click();
+    }
 }
 
 }

src/Button.hpp

@@ -1,4 +1,5 @@
 #include <string>
+#include <functional>
 #include "Widget.hpp"
 #include "RGB.hpp"
 #include "pango/pango-font.h"
@@ -19,6 +20,8 @@ public:
     void set_text(std::string text) { m_text = text; wants_repaint(); }
     std::string &get_text() { return m_text; }
 
+    std::function<void()> on_click { [](){} };
+protected:
     void on_paint();
     void on_init();
     void on_focus_update(FocusUpdateEvent &event);

src/main.cpp

@@ -15,6 +15,10 @@ int main() {
     main_widget.set_do_background_fill(true);
     window.set_main_widget(&main_widget);
 
+    button.on_click = [&button]() {
+        button.set_text("clicked!");
+    };
+
     main_widget.add_child(&button);
 
     window.run(true);