[evolution] hook out X symbols via g_module to avoid direct X linkage.

[Michael Meeks <michael src gnome org>]

commit e16baf2b51cdbf2bd4d1feb9507603c261599d11
Author: Michael Meeks <michael meeks novell com>
Date:   Wed Apr 7 17:49:19 2010 +0100

    hook out X symbols via g_module to avoid direct X linkage.

 shell/e-shell-meego.c |   63 +++++++++++++++++++++++++++++++++---------------
 1 files changed, 43 insertions(+), 20 deletions(-)
---
diff --git a/shell/e-shell-meego.c b/shell/e-shell-meego.c
index 63342f1..70401c1 100644
--- a/shell/e-shell-meego.c
+++ b/shell/e-shell-meego.c
@@ -37,9 +37,6 @@ void e_shell_detect_meego (gboolean *is_meego, gboolean *small_screen)
 #else
 void e_shell_detect_meego (gboolean *is_meego, gboolean *small_screen)
 {
-	/* cannot compile on Fedora, disabling for now */
-	*is_meego = *small_screen = FALSE;
-	/*
 	GdkAtom wm_win, mob_atom;
 	Atom dummy_t;
 	unsigned long dummy_l;
@@ -48,6 +45,18 @@ void e_shell_detect_meego (gboolean *is_meego, gboolean *small_screen)
 	GdkDisplay *display;
 	Window *wm_window_v = NULL;
 	unsigned char *moblin_string = NULL;
+	GModule *module;
+	/*
+	 * Wow - this is unpleasant, but it is hard to link directly
+	 * to the X libraries, and we have to use XGetWindowProperty
+	 * to get to the (mind-mashed) 'supporting' window.
+	 */
+	struct {
+	  int (*XFree) (void *);
+	  int (*XGetWindowProperty) (Display*, XID, Atom, long, long, Bool,
+				     Atom, Atom *, int *, unsigned long*,
+				     unsigned long*, unsigned char**);
+	} fns = { 0, 0 };
 
 	*is_meego = *small_screen = FALSE;
 
@@ -59,25 +68,36 @@ void e_shell_detect_meego (gboolean *is_meego, gboolean *small_screen)
 	if (!wm_win || !mob_atom)
 		return;
 
+	module = g_module_open (NULL, 0);
+	if (!module)
+		return;
+	g_module_symbol (module, "XFree", (gpointer) &fns.XFree);
+	g_module_symbol (module, "XGetWindowProperty",
+						  (gpointer) &fns.XGetWindowProperty);
+	if (!fns.XFree || !fns.XGetWindowProperty) {
+		fprintf (stderr, "defective X server\n");
+		goto exit;
+	}
+
 	display = gdk_display_get_default ();
 	screen = gdk_display_get_default_screen (gdk_display_get_default());
 
 	gdk_error_trap_push ();
 
-	/* get the window manager's supporting window * /
-	XGetWindowProperty (gdk_x11_display_get_xdisplay (display), 
-			    GDK_WINDOW_XID (gdk_screen_get_root_window (screen)),
-			    gdk_x11_atom_to_xatom_for_display (display, wm_win),
-			    0, 1, False, XA_WINDOW, &dummy_t, &dummy_i,
-			    &dummy_l, &dummy_l, (unsigned char **)(&wm_window_v));
+	/* get the window manager's supporting window */
+	fns.XGetWindowProperty (gdk_x11_display_get_xdisplay (display), 
+				GDK_WINDOW_XID (gdk_screen_get_root_window (screen)),
+				gdk_x11_atom_to_xatom_for_display (display, wm_win),
+				0, 1, False, XA_WINDOW, &dummy_t, &dummy_i,
+				&dummy_l, &dummy_l, (unsigned char **)(&wm_window_v));
 	
-	/* get the '_Moblin' setting * /
+	/* get the '_Moblin' setting */
 	if (wm_window_v && (*wm_window_v != None))
-		XGetWindowProperty (gdk_x11_display_get_xdisplay (display), *wm_window_v,
-				    gdk_x11_atom_to_xatom_for_display (display, mob_atom),
-				    0, 8192, False, XA_STRING,
-				    &dummy_t, &dummy_i, &dummy_l, &dummy_l,
-				    &moblin_string);
+		fns.XGetWindowProperty (gdk_x11_display_get_xdisplay (display), *wm_window_v,
+					gdk_x11_atom_to_xatom_for_display (display, mob_atom),
+					0, 8192, False, XA_STRING,
+					&dummy_t, &dummy_i, &dummy_l, &dummy_l,
+					&moblin_string);
 
 	gdk_error_trap_pop ();
 
@@ -87,7 +107,7 @@ void e_shell_detect_meego (gboolean *is_meego, gboolean *small_screen)
 
 		g_warning ("prop '%s'", moblin_string);
 
-		/* use meego theming tweaks * /
+		/* use meego theming tweaks */
 		*is_meego = TRUE;
 
 		props = g_strsplit ((gchar *)moblin_string, ":", -1);
@@ -97,22 +117,25 @@ void e_shell_detect_meego (gboolean *is_meego, gboolean *small_screen)
 			g_warning ("pair '%s'='%s'", pair ? pair[0] : "<null>",
 				   pair && pair[0] ? pair[1] : "<null>");
 
-			/* Hunt for session-type=small-screen * /
+			/* Hunt for session-type=small-screen */
 			if (pair && pair[0] && !g_ascii_strcasecmp (pair[0], "session-type"))
 				*small_screen = !g_ascii_strcasecmp (pair[1], "small-screen");
 			g_strfreev (pair);
 		}
 		g_strfreev (props);
-		XFree (moblin_string);
+		fns.XFree (moblin_string);
 	}
 
+ exit:
 	if (wm_window_v)
-	      XFree (wm_window_v);*/
+	      fns.XFree (wm_window_v);
+
+	g_module_close (module);
 }
 #endif
 
 #ifdef TEST_APP
-/* gcc -g -O0 -Wall -I. -DTEST `pkg-config --cflags --libs gtk+-2.0` e-shell-meego.c && ./a.out */
+/* gcc -g -O0 -Wall -I. -DTEST_APP `pkg-config --cflags --libs gtk+-2.0` e-shell-meego.c && ./a.out */
 #include <gtk/gtk.h>
 
 int main (int argc, char **argv)