Re: Control user change of SpinButton value

[Paul Breeuwsma <gtkmm paulinternet nl>]

Josepo Urrutia wrote:
> If I use the Gtk::SpinButton::signal_value_changed I can do a callback
> whenever the value of a spinbutton is changed, the problem is that this
> callback is also fired if the value is changed by the code not only by the
> user.

Here is some code that doubles the value of the spinbutton after someone 
changed it. Maybe you can use it.
#include <gtkmm.h>

void update (Gtk::SpinButton *spinbutton)
{
  static bool code = false;
  
  if(code)
  {
    code = false;
  }
  else
  {
    spinbutton->set_value(2.0 * spinbutton->get_value());
    code = true;
  }
}

int main (int argc, char **argv)
{
  Gtk::Main gtk(argc, argv);
  Gtk::Window window;
  Gtk::SpinButton spinbutton;
  
  spinbutton.set_range(0.0, 1000.0);
  spinbutton.set_increments(1.0, 1.0);
  spinbutton.signal_value_changed().connect(sigc::bind(sigc::ptr_fun(&update), &spinbutton));
  
  window.add(spinbutton);
  window.set_border_width(10);
  window.show_all();
  
  Gtk::Main::run(window);
  return 0;
}