C++ conversion (#80)

Converted project to C++

Tactility/Source/Services/Gui/ViewPort.h

@@ -0,0 +1,46 @@
+#pragma once
+
+#include "App.h"
+#include "lvgl.h"
+
+namespace tt::service::gui {
+
+/** ViewPort Draw callback
+ * @warning    called from GUI thread
+ */
+typedef void (*ViewPortShowCallback)(App app, lv_obj_t* parent);
+typedef void (*ViewPortHideCallback)(App app);
+
+// TODO: Move internally, use handle publicly
+
+typedef struct {
+    App app;
+    ViewPortShowCallback on_show;
+    ViewPortHideCallback _Nullable on_hide;
+    bool app_toolbar;
+} ViewPort;
+
+/** ViewPort allocator
+ *
+ * always returns view_port or stops system if not enough memory.
+ * @param app
+ * @param on_show Called to create LVGL widgets
+ * @param on_hide Called before clearing the LVGL widget parent
+ *
+ * @return     ViewPort instance
+ */
+ViewPort* view_port_alloc(
+    App app,
+    ViewPortShowCallback on_show,
+    ViewPortHideCallback on_hide
+);
+
+/** ViewPort deallocator
+ *
+ * Ensure that view_port was unregistered in GUI system before use.
+ *
+ * @param      view_port  ViewPort instance
+ */
+void view_port_free(ViewPort* view_port);
+
+} // namespace