Added preset type enumeration

src/GUI/Plater.hpp

@@ -36,6 +36,14 @@ enum class UndoCmd {
     Remove, Add, Reset, Increase, Decrease, Rotate
 };
 
+/// Preset tab list
+enum class preset_t : uint8_t {
+    Print = 0, Material, Printer,
+    Last // This MUST be the last enumeration. Don't use it for anything.
+};
+/// Convenience counter to determine how many preset tabs exist.
+constexpr size_t preset_count = static_cast<uint8_t>(preset_t::Last);
+
 enum class Zoom {
     In, Out
 };