introduce get_screen_count(...) function

screen.c

@@ -121,6 +121,23 @@ get_screen_bycoord(Display *disp, int x, int y)
     return -1;
 }
 
+/** Return the actual screen count
+ * \param disp Display ref
+ * \return the number of screen available
+ */
+int
+get_screen_count(Display *disp)
+{
+    int screen_number;
+
+    if(XineramaIsActive(disp))
+        XineramaQueryScreens(disp, &screen_number);
+    else
+        return ScreenCount(disp);
+
+    return screen_number;
+}
+
 void
 uicb_focusnextscreen(Display *disp,
                      DC *drawcontext,

screen.h

@@ -31,6 +31,7 @@ typedef XineramaScreenInfo ScreenInfo;
 ScreenInfo * get_screen_info(Display *, int, Statusbar *, int *);
 ScreenInfo * get_display_info(Display *, int, Statusbar);
 int get_screen_bycoord(Display *, int, int);
+int get_screen_count(Display *);
 UICB_PROTO(uicb_focusnextscreen);
 UICB_PROTO(uicb_focusprevscreen);