C++ refactoring (#91)

Tactility/Private/service/gui/ViewPort_i.h

@@ -0,0 +1,23 @@
+#pragma once
+
+#include "service/gui/ViewPort.h"
+
+namespace tt::service::gui {
+
+/** Process draw call. Calls on_show callback.
+ * To be used by GUI, called on redraw.
+ *
+ * @param      view_port  ViewPort instance
+ * @param      canvas     canvas to draw at
+ */
+void view_port_show(ViewPort* view_port, lv_obj_t* parent);
+
+/**
+ * Process draw clearing call. Calls on_hdie callback.
+ * To be used by GUI, called on redraw.
+ *
+ * @param view_port
+ */
+void view_port_hide(ViewPort* view_port);
+
+} // namespace