[gdm] simple-greeter: Don't request an invalid size

[Ray Strode <halfline src gnome org>]

commit 9694ea8e7a179060e122bbf9890829321c7fedeb
Author: Benjamin Otte <otte redhat com>
Date:   Sat Apr 2 04:10:09 2011 +0200

    simple-greeter: Don't request an invalid size
    
    GTK widgets must at all times report a size they can handle. So it is
    not allowed to return 0 when not realized, because then size allocations
    break when GTK uses this size for its widget.
    In this case, GTK uses the pre-realize size to determine the size it
    should request when creating the greeter window - chicken and egg so to
    say.
    
    This patch just uses the default monitor (I guess the root window's
    monitor is the default monitor?) for determining the login window size.
    
    One thing this patch doesn't do is add a call to gtk_widget_queue_resize()
    from the realize callback or from monitor-changing signals, though
    that's probably technically necessary.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=646498

 gui/simple-greeter/gdm-greeter-login-window.c |   30 ++++++++++---------------
 1 files changed, 12 insertions(+), 18 deletions(-)
---
diff --git a/gui/simple-greeter/gdm-greeter-login-window.c b/gui/simple-greeter/gdm-greeter-login-window.c
index e323bc2..11f5469 100644
--- a/gui/simple-greeter/gdm-greeter-login-window.c
+++ b/gui/simple-greeter/gdm-greeter-login-window.c
@@ -1549,25 +1549,23 @@ gdm_greeter_login_window_get_preferred_width (GtkWidget *widget,
 {
         int             monitor;
         GdkScreen      *screen;
+        GdkWindow      *window;
         GdkRectangle    area;
         GtkAllocation   widget_allocation;
         int             min_size;
         int             nat_size;
 
-        min_size = 0;
-        nat_size = 0;
-
-        if (!gtk_widget_get_realized (widget)) {
-                goto out;
-        }
-
         gtk_widget_get_preferred_width (gtk_bin_get_child (GTK_BIN (widget)),
                                         &min_size,
                                         &nat_size);
 
         /* Make width be at least 33% screen width */
         screen = gtk_widget_get_screen (widget);
-        monitor = gdk_screen_get_monitor_at_window (screen, gtk_widget_get_window (widget));
+        window = gtk_widget_get_window (widget);
+        if (window == NULL) {
+                window = gdk_screen_get_root_window (screen);
+        }
+        monitor = gdk_screen_get_monitor_at_window (screen, window);
         gdk_screen_get_monitor_geometry (screen, monitor, &area);
         min_size = MAX (min_size, .33 * area.width);
         nat_size = MAX (nat_size, .33 * area.width);
@@ -1578,7 +1576,6 @@ gdm_greeter_login_window_get_preferred_width (GtkWidget *widget,
         min_size = MAX (min_size, widget_allocation.width);
         nat_size = MAX (nat_size, widget_allocation.width);
 
- out:
         if (minimum_size)
                 *minimum_size = min_size;
         if (natural_size)
@@ -1592,29 +1589,26 @@ gdm_greeter_login_window_get_preferred_height (GtkWidget *widget,
 {
         int             monitor;
         GdkScreen      *screen;
+        GdkWindow      *window;
         GdkRectangle    area;
         int             min_size;
         int             nat_size;
 
-        min_size = 0;
-        nat_size = 0;
-
-        if (!gtk_widget_get_realized (widget)) {
-                goto out;
-        }
-
         gtk_widget_get_preferred_height (gtk_bin_get_child (GTK_BIN (widget)),
                                         &min_size,
                                         &nat_size);
 
         /* Make height be at most 80% of screen height */
         screen = gtk_widget_get_screen (widget);
-        monitor = gdk_screen_get_monitor_at_window (screen, gtk_widget_get_window (widget));
+        window = gtk_widget_get_window (widget);
+        if (window == NULL) {
+                window = gdk_screen_get_root_window (screen);
+        }
+        monitor = gdk_screen_get_monitor_at_window (screen, window);
         gdk_screen_get_monitor_geometry (screen, monitor, &area);
         min_size = MIN (min_size, .8 * area.height);
         nat_size = MIN (nat_size, .8 * area.height);
 
- out:
         if (minimum_size)
                 *minimum_size = min_size;
         if (natural_size)