saving gtk window position - c

Question

I'm trying to save the gtk window position(absolute) to restore it wehn I open the applicaiton again
here's my code so far:
gint x,y;
gtk_window_get_position(main_window,&x,&y);
printf("current position is:\nx: %i\ny:%i\n",x,y);
this code runs when the application exits, I always get:
current position is:
x: 0
y:0
What am I doing wrong.

Answer 1

gtk_window_get_position usually does a best guess but you cannot rely on it because
the X Window System does not specify a way to obtain the geometry of
the decorations placed on a window by the window manager.
(from gtk_window_get_position reference)
To see the function in action, try something like below:
#include <gtk/gtk.h>
int main(int argv, char* argc[])
{
GtkWidget *window, *button;
gint x, y;
gtk_init(&argv, &argc);
window = gtk_window_new(GTK_WINDOW_TOPLEVEL);
gtk_window_set_title(GTK_WINDOW(window), "Test Window");
button = gtk_button_new_with_label("Close");
g_signal_connect(G_OBJECT(button), "clicked",
G_CALLBACK(gtk_main_quit), (gpointer)NULL);
gtk_container_set_border_width(GTK_CONTAINER(window), 10);
gtk_container_add(GTK_CONTAINER(window), button);
gtk_window_get_position(GTK_WINDOW(window), &x, &y);
printf("current position is:\nx: %i\ny:%i\n", x, y);
gtk_window_set_position(GTK_WINDOW(window),
GTK_WIN_POS_CENTER_ALWAYS);
gtk_window_get_position(GTK_WINDOW(window), &x, &y);
printf("new position is:\nx: %i\ny:%i\n", x, y);
gtk_widget_show_all(window);
gtk_main();
}
Edit
If you wish the window to appear at a specific location, you could try something like:
gtk_window_move(GTK_WINDOW(window), 420, 180);
However the above function should be placed after
gtk_widget_show_all(window);
because
most window managers ignore requests for initial window positions
(instead using a user-defined placement algorithm) and honor requests
after the window has already been shown.
(from gtk_window_move reference)

Answer 2

I've just implemented this feature using pygobject; it's not C but it could still be useful to have a look at it.
You can find the code here.
I've used GNOME Builder's default template for a python GNOME application, so it should be super-easy to replicate if you set your project with it.