Re: get_window() returns NULL

["Diego Fdez." Durán <diego goedi net>]

Hi, i think that this example code will explain something :)

--------------------------
#include <gtkmm.h>
#include <iostream>

class MainWindow : public Gtk::Window
{
      public:
              MainWindow()
              {
                      Glib::RefPtr<Gdk::Window> w = this->get_window();
                      if(!w)
                              std::cout << "w NULL" << std::endl;

                      show();
                      if(!w)
                              std::cout << "w still NULL" << std::endl;
              }

              void MainWindow::test()
              {
                      Glib::RefPtr<Gdk::Window> w = this->get_window();

                      std::cout << "Test" << std::endl;

                      if(!w)
                              std::cout << "Test: w NULL" << std::endl;
              }

              ~MainWindow(){}
};


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

        MainWindow mainWindow;
        mainWindow.test();

        Gtk::Main::run(mainWindow);

        exit(0);
}

-----------------------------------------

The exit on console is:

gooz Lain:~/Desktop/prueba$ ./ejemplo w NULL
w still NULL
Test

----------------------

I hope this helps. The window must be realized before you can use
get_window();

:)

El jue, 16-06-2005 a las 00:00 +0200, Andrea Spadaccini escribió:
> Hi everyone,
> I've got a problem with get_window().. gdb backtrace shows me that a
> segfault is caused by this function returning NULL from inside a member
> of my SubnetRenderer class, which is derived from Gtk::Drawable. here's
> the function that generates the problem:
> 
> void SubnetRenderer::setStatus(int s) {
>     Gdk::Cursor ar(Gdk::ARROW);
>     Gdk::Cursor ch(Gdk::CROSSHAIR);
> 
>     // Non funge, non capisco perché..
>     Glib::RefPtr<Gdk::Window> w = get_window();
>     std::cout << "Sono qui! :)\n";
>     Gdk::Color c("black");
>     //gc->set_foreground(mainColor);
>     if(w == NULL)
>         std::cout << "E' NULL!!!\n";
>     w->set_cursor(ar);
>     
>     switch(s) {
>         case DEFAULT:
>             sb_text = "Selezionare un oggetto per informazioni";
>             break;
>         case ADD_HOST:
>             cleanSelections();
>             sb_text = "Cliccare su un punto della mappa per aggiungere
> un host."; break;
>         case ADD_ROUTER:
>             cleanSelections();
>             //get_window()->set_cursor(ch);
>             sb_text = "Cliccare su un punto della mappa per aggiungere
> un router."; break;
>         case SOMETHING_IS_SELECTED:
>             sb_text = selected->getInfo();
>             break;
>         default:
>             sb_text = "Questo stato è impossibile. Come direbbe
> Nunnari: \"Sei un PIIIIRLA\""; break;
>     }
>     status = s;
> }
> 
> and here's the backtrace
> 
> [...]
> 
> (gdb) run
> Starting program: /home/andrea/Uni/Reti di Calcolatori/simulatore_reti/
> Sim Sono qui! :)
> E' NULL!!!
> 
> Program received signal SIGSEGV, Segmentation fault.
> Gdk::Window::set_cursor(Gdk::Cursor const&) (this=0x0,
> cursor= 0xbffff110) at window.h:719
> 719     window.h: No such file or directory.
>         in window.h
> (gdb) bt
> #0  Gdk::Window::set_cursor(Gdk::Cursor const&) (this=0x0,
> cursor= 0xbffff110) at window.h:719
> #1  0x08094f6d in SubnetRenderer::setStatus(int) (this=0xbffff4a0, s=0)
>     at SubnetRenderer.cpp:178
> #2  0x08093f5a in SubnetRenderer (this=0xbffff4a0, xsize=700, ysize=600,
>     dwb=0x0, ldwb=0x0) at SubnetRenderer.cpp:40
> #3  0x08099ee6 in TestWindow (this=0xbffff490) at TestWindow.cpp:25
> #4  0x080a1705 in main (argc=1, argv=0xbffff854) at Tester.cpp:8
> #5  0x4093e469 in __libc_start_main () from /lib/libc.so.6
> (gdb)
> 
> 
> PLEASE HELP ME!! I'm going MAD!!
> thanks in advance!!
> 
> 
> _______________________________________________
> gtkmm-list mailing list
> gtkmm-list gnome org
> http://mail.gnome.org/mailman/listinfo/gtkmm-list
-- 
-----------------------------------
Diego Fdez. Durán <diego goedi net>
Web: http://www.goedi.net
GPG ID: 90D266BB
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