Why button press event only reacts on double click?

[Klaus Rudolph <lts-rudolph gmx de>]

The function "signal_button_press_event()" reacts only if I double click 
the button. Is it possible to react also on a single press event?



#include <iostream>
#include <gtkmm.h>
#include <gtkmm/window.h>

class ExampleWindow: public Gtk::Window
{
    Gtk::Button button;
    public:
    ExampleWindow(): button("Hallo")
    {
        add(button);
        button.signal_button_press_event().connect( [this]( 
GdkEventButton* ev)->bool{ std::cout << "Press" << std::endl; return 
true; });
    }
};


int main(int argc, char* argv[])
{
    Gtk::Main kit(argc, argv);

    ExampleWindow window;

    window.show_all_children();
    Gtk::Main::run(window);
    return 0;
}