[PATCH] add sn_internal_display_get_root_window()

[Julien Danjou]

Signed-off-by: Julien Danjou <julien at danjou.info>
---
 libsn/sn-common.c    |   19 +++++++++++++++++++
 libsn/sn-internals.h |    3 +++
 libsn/sn-xmessages.c |    4 ++--
 3 files changed, 24 insertions(+), 2 deletions(-)

diff --git a/libsn/sn-common.c b/libsn/sn-common.c
index b494ad7..35fd6d7 100644
--- a/libsn/sn-common.c
+++ b/libsn/sn-common.c
@@ -151,6 +151,25 @@ sn_internal_display_get_x_screen (SnDisplay *display,
 }
 
 /**
+ * sn_internal_display_get_root_window:
+ * @display: an #SnDisplay
+ * @number: screen number to get root window from
+ *
+ * Gets a root window; if the screen number
+ * does not exist, returns %NULL.
+ *
+ * Return value: X root window or %NULL
+ **/
+Window
+sn_internal_display_get_root_window (SnDisplay *display,
+                                     int       number)
+{
+    if (number < 0 || number >= display->n_screens)
+        return None;
+    return RootWindow (display->xdisplay, number);
+}
+
+/**
  * sn_display_process_event:
  * @display: a display
  * @xevent: X event
diff --git a/libsn/sn-internals.h b/libsn/sn-internals.h
index 0336a0d..5969a82 100644
--- a/libsn/sn-internals.h
+++ b/libsn/sn-internals.h
@@ -53,6 +53,9 @@ SN_BEGIN_DECLS
 Screen*    sn_internal_display_get_x_screen    (SnDisplay              *display,
                                                 int                     number);
 
+Window     sn_internal_display_get_root_window (SnDisplay              *display,
+                                                int                     number);
+
 void       sn_internal_display_get_xmessage_data (SnDisplay              *display,
                                                   SnList                **funcs,
                                                   SnList                **pending);
diff --git a/libsn/sn-xmessages.c b/libsn/sn-xmessages.c
index da7a8f4..50afb0a 100644
--- a/libsn/sn-xmessages.c
+++ b/libsn/sn-xmessages.c
@@ -64,7 +64,7 @@ sn_internal_add_xmessage_func (SnDisplay      *display,
   handler = sn_new0 (SnXmessageHandler, 1);
 
   handler->xdisplay = sn_display_get_x_display (display);
-  handler->root = RootWindow (handler->xdisplay, screen);
+  handler->root = sn_internal_display_get_root_window (display, screen);
   handler->type_atom = sn_internal_atom_get (display, message_type);
   handler->type_atom_begin = sn_internal_atom_get (display, message_type_begin);
   handler->message_type = sn_internal_strdup (message_type);
@@ -120,7 +120,7 @@ sn_internal_remove_xmessage_func (SnDisplay      *display,
   fhd.func = func;
   fhd.func_data = func_data;
   fhd.handler = NULL;
-  fhd.root = RootWindow (sn_display_get_x_display (display), screen);
+  fhd.root = sn_internal_display_get_root_window (display, screen);
   
   if (xmessage_funcs != NULL)
     sn_list_foreach (xmessage_funcs, find_handler_foreach, &fhd);
-- 
1.5.6.5