[mutter] Add meta_window_is_on_primary_monitor function

[Alexander Larsson <alexl src gnome org>]

commit eeca838778a77074806d3cb66df4d497c9d4bd43
Author: Alexander Larsson <alexl redhat com>
Date:   Wed Mar 9 13:04:18 2011 +0100

    Add meta_window_is_on_primary_monitor function
    
    This is useful in a couple of places to avoid opencoding it.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=609258

 src/core/window.c |   11 +++++++++++
 src/meta/window.h |    1 +
 2 files changed, 12 insertions(+), 0 deletions(-)
---
diff --git a/src/core/window.c b/src/core/window.c
index 5c845c2..3451f29 100644
--- a/src/core/window.c
+++ b/src/core/window.c
@@ -3213,6 +3213,17 @@ meta_window_is_fullscreen (MetaWindow *window)
   return window->fullscreen;
 }
 
+/**
+ * meta_window_is_on_primary_monitor:
+ *
+ * Return value: %TRUE if the window is on the primary monitor
+ */
+gboolean
+meta_window_is_on_primary_monitor (MetaWindow *window)
+{
+  return window->monitor->number == window->screen->primary_monitor_index;
+}
+
 void
 meta_window_tile (MetaWindow *window)
 {
diff --git a/src/meta/window.h b/src/meta/window.h
index 060cc1e..af5602c 100644
--- a/src/meta/window.h
+++ b/src/meta/window.h
@@ -126,6 +126,7 @@ void     meta_window_foreach_ancestor         (MetaWindow            *window,
 
 MetaMaximizeFlags meta_window_get_maximized (MetaWindow *window);
 gboolean          meta_window_is_fullscreen (MetaWindow *window);
+gboolean          meta_window_is_on_primary_monitor (MetaWindow *window);
 
 gboolean meta_window_is_mapped (MetaWindow  *window);
 gboolean meta_window_toplevel_is_mapped (MetaWindow  *window);