Move XRC pointer checking/error throwing to a templated function

src/wx/guiinit.cpp

@@ -7,6 +7,7 @@
 
 #include "wxvbam.h"
 
+#include <typeinfo>
 #include <stdexcept>
 
 #include <wx/stockitem.h>
@@ -2051,19 +2052,28 @@ public:
 } throttle_ctrl;
 
 /////////////////////////////
+///Check if a pointer from the XRC file is valid.  If it's not, throw an error telling the user.
+template <typename T>
+void CheckThrowXRCError(T pointer,std::string name)
+{
+    if(pointer == NULL)
+    {
+        std::string errormessage = "Unable to load a ";
+        errormessage+=typeid(pointer).name();
+        errormessage+=" from the builtin xrc file:  ";
+        errormessage+=name;
+        throw std::runtime_error(errormessage);
+    }
+}
+
 wxDialog * MainFrame::LoadXRCDialog(const char * name)
 {
     wxString dname = wxString::FromUTF8(name);
     /* using this instead of LoadDialog() allows non-wxDialog classes that */
     /* are derived from wxDialog (like wxPropertySheetDialog) to work */
     wxDialog * dialog = wxDynamicCast(wxXmlResource::Get()->LoadObject(this, dname, wxEmptyString), wxDialog);
-    if(!dialog)
-    {
-        std::string errormessage = "Unable to load a dialog from the builtin xrc file:  ";
-        errormessage+=name;
-        throw std::runtime_error(errormessage);
-        return NULL;
-    }
+    CheckThrowXRCError(dialog,name);
+
     /* wx-2.9.1 doesn't set parent for propertysheetdialogs for some reason */
     /* this will generate a gtk warning but it is necessary for later */
     /* retrieval using FindWindow() */