refactoring: application mode code split

scenarioloadermode.h

@@ -0,0 +1,41 @@
+/*
+This Source Code Form is subject to the
+terms of the Mozilla Public License, v.
+2.0. If a copy of the MPL was not
+distributed with this file, You can
+obtain one at
+http://mozilla.org/MPL/2.0/.
+*/
+
+#pragma once
+
+#include "applicationmode.h"
+
+class scenarioloader_mode : public application_mode {
+
+public:
+// constructors
+    scenarioloader_mode();
+// methods
+    // initializes internal data structures of the mode. returns: true on success, false otherwise
+    bool
+        init() override;
+    // mode-specific update of simulation data. returns: false on error, true otherwise
+    bool
+        update() override;
+    // maintenance method, called when the mode is activated
+    void
+        enter() override;
+    // maintenance method, called when the mode is deactivated
+    void
+        exit() override;
+    // input handlers
+    void
+        on_key( int const Key, int const Scancode, int const Action, int const Mods ) override { ; }
+    void
+        on_cursor_pos( double const Horizontal, double const Vertical ) override { ; }
+    void
+        on_mouse_button( int const Button, int const Action, int const Mods ) override { ; }
+    void
+        on_scroll( double const Xoffset, double const Yoffset ) override { ; }
+};