--- a/ui/wpf/toolkit.h	Sun Jan 25 15:01:04 2015 +0100
+++ b/ui/wpf/toolkit.h	Tue Jan 27 09:59:32 2015 +0100
@@ -41,6 +41,13 @@
 #define UI_IMPORT __declspec(dllimport)
 __declspec(dllimport) int  __stdcall myfunc(char *str);
 
+typedef struct UiEventData {
+    UiObject    *obj;
+    ui_callback callback;
+    void        *user_data;
+    int         value;
+} UiEventData;
+
 UI_IMPORT void __stdcall UIinit(char *appname);
 UI_IMPORT void __stdcall UImain();
 UI_IMPORT void __stdcall UIshow(UIWIDGET widget);