Hello.
My question is about the order in which widgets get exposure event.
I have the following widgets packing:
1. main_window->hbox1->hbox12->frame1->vbox121
Output:
Code:
expose_event: I'm [ window ]
expose_event: I'm [ hbox1 ]
expose_event: I'm [ hbox12 ]
expose_event: I'm [ frame1 ]
expose_event: I'm [ vbox121 ]
Everything's fine
2. Add a scrolled window:
main_window->hbox1->scroll1->hbox12->frame1->vbox121
Output:
Code:
expose_event: I'm [ hbox12 ]
expose_event: I'm [ frame1 ]
expose_event: I'm [ vbox121 ]
expose_event: I'm [ window ]
expose_event: I'm [ hbox1 ]
Why the order have changed?
I always thought that "window" is the first who gets an exposure event, and then as the packaging goes.
Thanx.
Here is the code:
Code:
#include <gtk/gtk.h>
#include <glib/gprintf.h>
GtkWidget *window;
GtkWidget *hbox1, *hbox12, *hbox13, *vbox1, *vbox12, *vbox13;
GtkWidget *vbox121;
GtkWidget *scroll1, *frame1, *frame2;
#define register_expose_callback(widget) do \
{ \
g_signal_connect(GTK_OBJECT(widget), "expose_event", (GtkSignalFunc)expose_event, #widget); \
} while (0)
static gboolean
expose_event(GtkWidget *widget, GdkEventExpose *event, gpointer user_data)
{
g_printf("%s: I'm [ %s ]\n", __func__, (gchar *)user_data);
return FALSE;
}
int
main(int argc, char *argv[])
{
gtk_init(&argc, &argv);
window = gtk_window_new(GTK_WINDOW_TOPLEVEL);
gtk_widget_set_size_request(GTK_WIDGET(window), 800, 400);
gtk_window_set_title(GTK_WINDOW(window), "g3");
g_signal_connect_swapped(G_OBJECT(window), "destroy", G_CALLBACK(gtk_main_quit), NULL);
register_expose_callback(window);
hbox1 = gtk_hbox_new(FALSE, 0);
register_expose_callback(hbox1);
gtk_widget_show(hbox1);
gtk_container_add(GTK_CONTAINER(window), hbox1);
hbox12 = gtk_hbox_new(FALSE, 0);
register_expose_callback(hbox12);
gtk_widget_show(hbox12);
#if 1
scroll1 = gtk_scrolled_window_new(NULL, NULL);
register_expose_callback(scroll1);
gtk_scrolled_window_add_with_viewport(GTK_SCROLLED_WINDOW(scroll1), hbox12);
gtk_scrolled_window_set_policy(GTK_SCROLLED_WINDOW(scroll1), GTK_POLICY_AUTOMATIC, GTK_POLICY_AUTOMATIC);
gtk_box_pack_start(GTK_BOX(hbox1), scroll1, TRUE, TRUE, 2);
gtk_widget_show(scroll1);
#else
gtk_box_pack_start(GTK_BOX(hbox1), hbox12, TRUE, TRUE, 2);
#endif
////
vbox121 = gtk_vbox_new(FALSE, 0);
register_expose_callback(vbox121);
frame1 = gtk_frame_new(" BlahBlah ");
register_expose_callback(frame1);
gtk_container_add(GTK_CONTAINER(frame1), vbox121);
gtk_box_pack_start(GTK_BOX(hbox12), frame1, FALSE, TRUE, 2);
gtk_widget_show(hbox12);
gtk_widget_show(frame1);
gtk_widget_show(vbox121);
gtk_widget_show(window);
gtk_main();
return 0;
}
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