diff --git a/src/Application/GuiEventType.h b/src/Application/GuiEventType.h
new file mode 100644
index 0000000..7b60128
--- /dev/null
+++ b/src/Application/GuiEventType.h
@@ -0,0 +1,18 @@
+#pragma once
+
+namespace ofx {
+namespace piMapper {
+
+struct GuiEventType {
+	enum {
+		SURFACE_HIT,
+		SURFACE_DRAGGED,
+		SURFACE_RELEASED,
+		HANDLE_HIT,
+		HANDLE_DRAGGED,
+		HANDLE_RELEASED
+	};
+};
+
+} // namespace piMapper
+} // namespace ofx
\ No newline at end of file