How to make gtk_window_set_position of gtk work? - c

Question

I want to set the position of the window using gtk_window_set_position
but it seems that after the window is created, the gtk_window_set_position will not take effect.
I'm wondering how to call gtk_window_set_position after the window shows up, i.e. a button event?

Answer 1

I just wrote a minimal working example that implements two approaches. One approach uses gtk_window_move and the other gtk_window_set_position.
If you have the gtk+ reference at hand the code should be self explanatory.
#include <gtk/gtk.h>
#include <glib.h>
void
button1_clicked_cb (GtkWidget * widget, GtkWindow * window)
{
GdkWindow *root;
gint width, height, rwidth, rheight;
gtk_window_get_size (window, &width, &height);
root = gtk_widget_get_root_window (GTK_WIDGET (window));
gdk_window_get_geometry (root, NULL, NULL, &rwidth,
&rheight);
gtk_window_move (window, (rwidth - width) / 2,
(rheight - height) / 2);
}
void
button2_clicked_cb (GtkWidget * widget, GtkWindow * window)
{
gtk_widget_hide (GTK_WIDGET (window));
gtk_window_set_position(GTK_WINDOW(window), GTK_WIN_POS_CENTER);
gtk_widget_show_all (GTK_WIDGET (window));
}
int
main (int argc, char *argv[])
{
GtkWidget *window;
GtkWidget *box;
GtkWidget *button1;
GtkWidget *button2;
gtk_init (&argc, &argv);
window = gtk_window_new (GTK_WINDOW_TOPLEVEL);
button1 = gtk_button_new_with_label ("approach 1");
button2 = gtk_button_new_with_label ("approach 2");
box = gtk_box_new (GTK_ORIENTATION_VERTICAL, 10);
gtk_box_pack_start (GTK_BOX (box), button1, TRUE, TRUE,
10);
gtk_box_pack_start (GTK_BOX (box), button2, TRUE, TRUE,
10);
gtk_container_add (GTK_CONTAINER (window), box);
gtk_widget_show_all (window);
g_signal_connect (window, "destroy",
G_CALLBACK (gtk_main_quit), NULL);
g_signal_connect (button1, "clicked",
G_CALLBACK (button1_clicked_cb),
window);
g_signal_connect (button2, "clicked",
G_CALLBACK (button2_clicked_cb),
window);
gtk_main ();
return 0;
}