ContextManager was done

source/States/GameState/ContextManager.cpp

+#include <States/GameState/ContextManager.h>
+
+void ContextManager::reset(GameContext&& context) {
+    while (!m_contexts.empty())
+        m_contexts.pop();
+    m_initial_context = std::move(context);
+    m_contexts.emplace(m_initial_context.clone());
+}
+
+void ContextManager::save_context() {
+    m_contexts.emplace(m_contexts.top().clone());
+}
+
+void ContextManager::restore_previous_context() {
+    if (m_contexts.size() > 1)
+        m_contexts.pop();
+    else
+        m_contexts.top() = m_initial_context.clone();
+}

source/States/GameState/ContextManager.h

+#pragma once
+#include <States/GameState/GameContext.h>
+#include <stack>
+
+class ContextManager {
+public:
+    void reset(GameContext&& context);
+    GameContext& get_current_context() { return m_contexts.top(); }
+    void save_context();
+    void restore_previous_context();
+private:
+    GameContext m_initial_context;
+    std::stack<GameContext> m_contexts;
+};

source/States/GameState/GameState.cpp

-#include "GameState.h"
+#include <States/GameState/GameState.h>
 #include <iostream> /// @todo remove it
 #include <States/ExitState/ExitState.h>
 

source/States/GameState/GameState.h

 #pragma once
 #include <BasicAbstractions/IState.h>
 #include <BasicAbstractions/IWindowKeeper.h>
+#include <States/GameState/Maze/Maze.h>
+#include <States/GameState/ContextManager.h>
 
-struct GameState : IState, IWindowKeeper {
-    explicit GameState(IStateManager& state_manager, const sf::VideoMode& video_mode, const sf::String& window_title) : IState(state_manager), IWindowKeeper(video_mode, window_title) {}
+class GameState : IState, IWindowKeeper {
+public:
+    explicit GameState(IStateManager& state_manager, const sf::VideoMode& video_mode, const sf::String& window_title) :
+        IState(state_manager), IWindowKeeper(video_mode, window_title) {}
     bool do_step() override;
+    void set_maze(Maze&& maze) { m_maze = std::move(maze); }
+    void set_context(GameContext&& context) { m_context_manager.reset(std::move(context)); }
+private:
     void event_handling() override {};
     void update() override {};
     void render() override {};
+private:
+    Maze m_maze;
+    ContextManager m_context_manager;
 };
 

source/States/GameState/Maze/Maze.h

@@ -6,6 +6,7 @@
 
 class Maze : public IDrawable {
 public:
+    Maze() = default;
     explicit Maze(std::vector<std::unique_ptr<Room>> rooms) : m_rooms(std::move(rooms)) {}
     void draw_into(sf::RenderWindow& window) const override;
 private:

source/States/SelectState/SelectState.h

@@ -33,6 +33,7 @@ public:
     explicit SelectState(IStateManager& state_manager, const sf::VideoMode& video_mode, const sf::String& window_title) :
     IState(state_manager), IWindowKeeper(video_mode, window_title), m_menu(state_manager) {}
     bool do_step() override;
+private:
     void event_handling() override;
     void update() override;
     void render() override;