Re: trouble with event propagation

[vronskij <vronskij gmail com>]

Hi,

thanks for the clarification. Now I get the picture. I am familiar with the wxWidgets library (wrapper of the GTK+), where the propagation with wxButton works.
But it works due to wxWidgets own event handling  system. I was a bit misled by this. 

jan bodnar

On Wed, Apr 2, 2008 at 6:28 AM, varun shrivastava <iluvubuntu gmail com> wrote:

hi

   the GtkButton  widget is handling the event and is returning TRUE,
thats why the event is not getting propagated to parents .

button-press-event is RUN-LAST so first your handler is called which returns FALSE,
than default handler from GtkButton is called which returns true.

Thats why if you connect using g_signal_connect_after than none of your handler will get called


See  gtk_button_button_press handler in gtkbutton.c

bye
varun

2008/3/31 vronskij <vronskij gmail com>:

Hi,

I have a small code example, It should demonstrate the event propagation
in GTK+.

I have three widgets. A button, fixed container and a window. I have three
callbacks. After I click on the button, I expect a message from all these three widgets. First from the button, then from fixed container and from the window.
I must be missing something, cause it is not working. I am getting message only from the button widget.

How should I modify the example, so that the code works?
Thanks for your suggestions.

jan bodnar

#include <gtk/gtk.h>

static gboolean button_reached(GtkWidget *widget, GdkEvent *event, gpointer data)
{
   g_print("button widget reached");

   return FALSE;
}


static gboolean fixed_reached(GtkWidget *widget, GdkEvent *event,  gpointer data)
{
   g_print("fixed container reached");

   return FALSE;
}
  

static gboolean window_reached(GtkWidget *widget, gpointer data)
{
   g_print("window widget reached");

   return FALSE;
}

int main( int argc, char *argv[])
{

  GtkWidget *window;
  GtkWidget *fixed;
  GtkWidget *button;

  gtk_init(&argc, &argv);

  window = gtk_window_new(GTK_WINDOW_TOPLEVEL);
  gtk_window_set_position(GTK_WINDOW(window), GTK_WIN_POS_CENTER);
  gtk_window_set_default_size(GTK_WINDOW(window), 230, 150);
  gtk_window_set_title(GTK_WINDOW(window), "Simple");
  gtk_widget_add_events(window, GDK_BUTTON_PRESS_MASK);

  fixed = gtk_fixed_new();
  gtk_widget_add_events(fixed, GDK_BUTTON_PRESS_MASK);

  button = gtk_button_new_with_label("Button");
  gtk_fixed_put(GTK_FIXED(fixed), button, 50, 50);
  gtk_container_add(GTK_CONTAINER(window), fixed);

  g_signal_connect(G_OBJECT(button), "button-press-event",
        G_CALLBACK(button_reached), NULL);

  g_signal_connect(G_OBJECT(fixed), "button-press-event",
        G_CALLBACK(fixed_reached), NULL);
 
  g_signal_connect(G_OBJECT(window), "button-press-event",
        G_CALLBACK(window_reached), NULL);

  g_signal_connect_swapped(G_OBJECT(window), "destroy",
        G_CALLBACK(gtk_main_quit), G_OBJECT(window));

  gtk_widget_show_all(window);

  gtk_main();

  return 0;
}

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