24 files changed, 437 insertions, 82 deletions

diff --git a/README.md b/README.md
index 6dc2bea..083f4f4 100644
--- a/README.md
+++ b/README.md
@@ -3,7 +3,6 @@ This is a c++ Linux CLI implementation of John Conway's game of life.
 
 # Todo
 - Implement the actual game
-- Multithreading
 - Dynamic terminal window size. Redraw everything when the window size changes
 - Cells can be eaten by other cells twice as large
 - Creatures with different abilities. Speed for example
diff --git a/src/CMakeLists.txt b/src/CMakeLists.txt
index c603b37..4aa4a40 100644
--- a/src/CMakeLists.txt
+++ b/src/CMakeLists.txt
@@ -15,7 +15,9 @@ file(GLOB SOURCES
 	argument_parser.cpp
 	util/color.cpp
 	game/game.cpp
-	game/cursor_listener.cpp
+	game/status_updater.cpp
+	game/generation_tracker.cpp
+	game/statusline.cpp
 	engine/engine.cpp
 	engine/data/vector2.cpp
 	engine/data/bounds.cpp
@@ -29,6 +31,7 @@ file(GLOB SOURCES
 	commands/insert_cell.cpp
 	commands/move_cursor.cpp
 	commands/quit.cpp
+	commands/toggle_pause.cpp
 	DI/object_type.cpp)
 
 add_executable(${PROJECT_NAME} ${SOURCES})
diff --git a/src/bootstrap.cpp b/src/bootstrap.cpp
index 713991d..8dec609 100644
--- a/src/bootstrap.cpp
+++ b/src/bootstrap.cpp
@@ -5,10 +5,13 @@
 #include "interfaces/cursor.hpp"
 #include "interfaces/engine.hpp"
 #include "interfaces/game.hpp"
+#include "interfaces/generation_tracker.hpp"
 #include "interfaces/input.hpp"
 #include "interfaces/matrix.hpp"
 #include "interfaces/randomization.hpp"
 #include "interfaces/scene.hpp"
+#include "interfaces/status_updater.hpp"
+#include "interfaces/statusline.hpp"
 #include "interfaces/window.hpp"
 
 // Implementations
@@ -22,6 +25,9 @@
 #include "engine/user/cursor.hpp"
 #include "engine/user/input.hpp"
 #include "game/game.hpp"
+#include "game/generation_tracker.hpp"
+#include "game/status_updater.hpp"
+#include "game/statusline.hpp"
 #include "randomization/generator.hpp"
 #include "randomization/seed_generator.hpp"
 
@@ -42,11 +48,21 @@ Container bootstrap() noexcept
 	container.bind<IWindow>().to<Window>();
 
 	container.bind<IGameFactory>().to_factory(normalize_lambda(
-		[](const std::shared_ptr<IWindow> &window, const std::shared_ptr<IScene> &scene,
-		   const std::shared_ptr<ICursorController> &cursor_controller)
+		[&container](const std::shared_ptr<IWindow> &window,
+					 const std::shared_ptr<IScene> &scene,
+					 const std::shared_ptr<ICursorController> &cursor_controller)
 		{
+			auto statusline =
+				container.get<IStatusLineFactory>()(cursor_controller, window);
+
+			auto generation_tracker = container.get<IGenerationTrackerFactory>()(true);
+
+			auto status_updater =
+				container.get<IStatusUpdaterFactory>()(statusline, generation_tracker);
+
 			return std::dynamic_pointer_cast<IGame>(
-				std::make_shared<Game>(window, scene, cursor_controller));
+				std::make_shared<Game>(window, scene, cursor_controller, statusline,
+									   generation_tracker, status_updater));
 		}));
 
 	container.bind<IRandomNumberGeneratorFactory>().to_factory(
@@ -79,5 +95,28 @@ Container bootstrap() noexcept
 										cursor_controller, window));
 		}));
 
+	container.bind<IStatusLineFactory>().to_factory(
+		[](const std::shared_ptr<ICursorController> &cursor_controller,
+		   const std::shared_ptr<IWindow> &window)
+		{
+			return std::dynamic_pointer_cast<IStatusLine>(
+				std::make_shared<StatusLine>(cursor_controller, window));
+		});
+
+	container.bind<IStatusUpdaterFactory>().to_factory(
+		[](const std::shared_ptr<IStatusLine> &status_line,
+		   const std::shared_ptr<IGenerationTracker> &generation_tracker)
+		{
+			return std::dynamic_pointer_cast<IStatusUpdater>(
+				std::make_shared<StatusUpdater>(status_line, generation_tracker));
+		});
+
+	container.bind<IGenerationTrackerFactory>().to_factory(
+		[](bool is_paused)
+		{
+			return std::dynamic_pointer_cast<IGenerationTracker>(
+				std::make_shared<GenerationTracker>(is_paused));
+		});
+
 	return container;
 }
diff --git a/src/commands/toggle_pause.cpp b/src/commands/toggle_pause.cpp
new file mode 100644
index 0000000..8a3f44c
--- /dev/null
+++ b/src/commands/toggle_pause.cpp
@@ -0,0 +1,22 @@
+#include "toggle_pause.hpp"
+
+#include <fmt/core.h>
+#include <utility>
+
+TogglePauseCommand::TogglePauseCommand(
+	std::shared_ptr<IGenerationTracker> generation_tracker,
+	std::shared_ptr<IStatusLine> statusline) noexcept
+	: _generation_tracker(std::move(generation_tracker)),
+	  _statusline(std::move(statusline))
+{
+}
+
+void TogglePauseCommand::execute() noexcept
+{
+	auto onoff = !_generation_tracker->get_is_paused();
+
+	_generation_tracker->set_is_paused(onoff);
+
+	_statusline->set_status(StatusLineSection::B,
+							fmt::format("Paused: {}", onoff ? "yes" : "no"));
+}
diff --git a/src/commands/toggle_pause.hpp b/src/commands/toggle_pause.hpp
new file mode 100644
index 0000000..4e05323
--- /dev/null
+++ b/src/commands/toggle_pause.hpp
@@ -0,0 +1,20 @@
+#pragma once
+
+#include "interfaces/command.hpp"
+#include "interfaces/generation_tracker.hpp"
+#include "interfaces/statusline.hpp"
+
+#include <memory>
+
+class TogglePauseCommand : public ICommand
+{
+public:
+	explicit TogglePauseCommand(std::shared_ptr<IGenerationTracker> generation_tracker,
+								std::shared_ptr<IStatusLine> statusline) noexcept;
+
+	void execute() noexcept override;
+
+private:
+	std::shared_ptr<IGenerationTracker> _generation_tracker;
+	std::shared_ptr<IStatusLine> _statusline;
+};
diff --git a/src/engine/engine.cpp b/src/engine/engine.cpp
index e463f28..c988c33 100644
--- a/src/engine/engine.cpp
+++ b/src/engine/engine.cpp
@@ -2,6 +2,7 @@
 
 #include "util/function.hpp"
 
+#include <thread>
 #include <utility>
 
 CLIGameEngine::CLIGameEngine(IGameFactory game_factory, ISceneFactory scene_factory,
@@ -38,7 +39,16 @@ void CLIGameEngine::start() noexcept
 
 	_configure_input(game->get_input_config());
 
-	_input_handler->listen();
+	std::thread listen_input_thread(normalize_lambda(
+		[this]()
+		{
+			_input_handler->listen();
+		}));
+
+	while (true)
+	{
+		game->on_update();
+	}
 }
 
 void CLIGameEngine::_configure_input(
diff --git a/src/engine/graphics/scene.cpp b/src/engine/graphics/scene.cpp
index 4e382fe..24c174f 100644
--- a/src/engine/graphics/scene.cpp
+++ b/src/engine/graphics/scene.cpp
@@ -45,26 +45,6 @@ void Scene::leave() noexcept
 	_is_shown = false;
 }
 
-void Scene::write_status(const std::string_view &str) noexcept
-{
-	const auto previous_position = _cursor_controller->where();
-
-	const auto window_size = _window->size();
-
-	_cursor_controller->move_to(
-		Vector2({.x = 2, .y = static_cast<Vector2::Value>(window_size.get_height())}),
-		true);
-
-	auto background_color = get_background_esc_seq(STATUSBAR_COLOR);
-
-	fmt::print("{}", background_color);
-	fmt::print(ERASE_ENTIRE_LINE, fmt::arg("esc", ESC));
-	fmt::print(fmt::runtime(str.data()));
-	fmt::print(RESET_ALL_MODES, fmt::arg("esc", ESC));
-
-	_cursor_controller->move_to(previous_position, true);
-}
-
 const std::shared_ptr<IMatrix<std::string_view>> &Scene::get_matrix() const noexcept
 {
 	return _matrix;
diff --git a/src/engine/graphics/scene.hpp b/src/engine/graphics/scene.hpp
index 1f1c51c..c4f6d67 100644
--- a/src/engine/graphics/scene.hpp
+++ b/src/engine/graphics/scene.hpp
@@ -12,10 +12,6 @@
 constexpr fmt::string_view ENABLE_ALT_BUFFER = "{esc}[?1049h";
 constexpr fmt::string_view DISABLE_ALT_BUFFER = "{esc}[?1049l";
 
-constexpr fmt::string_view ERASE_ENTIRE_LINE = "{esc}[2K";
-
-constexpr uint32_t STATUSBAR_COLOR = 0x1A1A1AU;
-
 class Scene : public IScene
 {
 public:
@@ -27,8 +23,6 @@ public:
 
 	void leave() noexcept override;
 
-	void write_status(const std::string_view &str) noexcept override;
-
 	[[nodiscard]] const std::shared_ptr<IMatrix<std::string_view>> &
 	get_matrix() const noexcept override;
 
diff --git a/src/engine/user/input.hpp b/src/engine/user/input.hpp
index 6a9edfd..51f3fcb 100644
--- a/src/engine/user/input.hpp
+++ b/src/engine/user/input.hpp
@@ -29,7 +29,9 @@ public:
 	void leave_raw_mode() noexcept override;
 
 private:
-	std::array<std::vector<std::shared_ptr<ISubscriber<Context>>>, CHAR_MAX> _subscribers;
+	std::array<std::vector<std::shared_ptr<ISubscriber<Context>>>,
+			   static_cast<std::size_t>(CHAR_MAX * 2U)>
+		_subscribers;
 
 	std::shared_ptr<termios> _original_termios = nullptr;
 
diff --git a/src/game/cursor_listener.cpp b/src/game/cursor_listener.cpp
deleted file mode 100644
index c815f08..0000000
--- a/src/game/cursor_listener.cpp
+++ /dev/null
@@ -1,14 +0,0 @@
-#include "cursor_listener.hpp"
-
-#include <fmt/core.h>
-#include <utility>
-
-CursorListener::CursorListener(std::shared_ptr<IScene> scene) noexcept
-	: _scene(std::move(scene))
-{
-}
-
-void CursorListener::update(const Vector2 &context) noexcept
-{
-	_scene->write_status(fmt::format("X: {}    Y {}", context.get_x(), context.get_y()));
-}
diff --git a/src/game/cursor_listener.hpp b/src/game/cursor_listener.hpp
deleted file mode 100644
index c74bb3d..0000000
--- a/src/game/cursor_listener.hpp
+++ /dev/null
@@ -1,19 +0,0 @@
-#pragma once
-
-#include "interfaces/scene.hpp"
-#include "interfaces/subscriber.hpp"
-
-#include "engine/data/vector2.hpp"
-
-#include <memory>
-
-class CursorListener : public ISubscriber<Vector2>
-{
-public:
-	explicit CursorListener(std::shared_ptr<IScene> scene) noexcept;
-
-	void update(const Vector2 &context) noexcept override;
-
-private:
-	std::shared_ptr<IScene> _scene;
-};
diff --git a/src/game/game.cpp b/src/game/game.cpp
index f788d15..6632c08 100644
--- a/src/game/game.cpp
+++ b/src/game/game.cpp
@@ -3,22 +3,31 @@
 #include "commands/insert_cell.hpp"
 #include "commands/move_cursor.hpp"
 #include "commands/quit.hpp"
-#include "game/cursor_listener.hpp"
+#include "commands/toggle_pause.hpp"
 
 #include <fmt/core.h>
 #include <iostream>
+#include <utility>
 
-Game::Game(const std::shared_ptr<IWindow> &window, const std::shared_ptr<IScene> &scene,
-		   const std::shared_ptr<ICursorController> &cursor_controller) noexcept
-	: _window(window), _scene(scene), _cursor_controller(cursor_controller)
+Game::Game(std::shared_ptr<IWindow> window, std::shared_ptr<IScene> scene,
+		   std::shared_ptr<ICursorController> cursor_controller,
+		   std::shared_ptr<IStatusLine> statusline,
+		   std::shared_ptr<IGenerationTracker> generation_tracker,
+		   std::shared_ptr<IStatusUpdater> status_updater) noexcept
+	: _window(std::move(window)),
+	  _scene(std::move(scene)),
+	  _cursor_controller(std::move(cursor_controller)),
+	  _statusline(std::move(statusline)),
+	  _generation_tracker(std::move(generation_tracker)),
+	  _status_updater(std::move(status_updater))
 {
 }
 
 void Game::on_start() noexcept
 {
-	auto cursor_listener = std::make_shared<CursorListener>(_scene);
+	_statusline->initialize_background();
 
-	_cursor_controller->subscribe(CursorEvent::POSITION_CHANGE, cursor_listener);
+	_cursor_controller->subscribe(CursorEvent::POSITION_CHANGE, _status_updater);
 
 	const auto window_size = _window->size();
 
@@ -28,9 +37,11 @@ void Game::on_start() noexcept
 
 	_cursor_controller->move_to(center_position);
 
-	cursor_listener->update(center_position);
+	_status_updater->update(center_position);
 }
 
+void Game::on_update() noexcept {}
+
 void Game::on_exit() const noexcept
 {
 	for (auto row : *_scene->get_matrix())
@@ -51,6 +62,7 @@ Game::get_input_config() const noexcept
 {
 	return {{'q', std::make_shared<QuitCommand>()},
 			{'i', std::make_shared<InsertCellCommand>(_cursor_controller, _scene)},
+			{'p', std::make_shared<TogglePauseCommand>(_generation_tracker, _statusline)},
 			{'k', std::make_shared<MoveCursorCommand>(Vector2::up(), _cursor_controller,
 													  _window)},
 			{'j', std::make_shared<MoveCursorCommand>(Vector2::down(), _cursor_controller,
diff --git a/src/game/game.hpp b/src/game/game.hpp
index 2493a42..5894a01 100644
--- a/src/game/game.hpp
+++ b/src/game/game.hpp
@@ -2,7 +2,10 @@
 
 #include "interfaces/cursor.hpp"
 #include "interfaces/game.hpp"
+#include "interfaces/generation_tracker.hpp"
 #include "interfaces/scene.hpp"
+#include "interfaces/status_updater.hpp"
+#include "interfaces/statusline.hpp"
 #include "interfaces/window.hpp"
 
 #include <memory>
@@ -10,18 +13,26 @@
 class Game : public IGame
 {
 public:
-	Game(const std::shared_ptr<IWindow> &window, const std::shared_ptr<IScene> &scene,
-		 const std::shared_ptr<ICursorController> &cursor_controller) noexcept;
+	Game(std::shared_ptr<IWindow> window, std::shared_ptr<IScene> scene,
+		 std::shared_ptr<ICursorController> cursor_controller,
+		 std::shared_ptr<IStatusLine> statusline,
+		 std::shared_ptr<IGenerationTracker> generation_tracker,
+		 std::shared_ptr<IStatusUpdater> status_updater) noexcept;
 
 	void on_start() noexcept override;
 
+	void on_update() noexcept override;
+
 	void on_exit() const noexcept override;
 
 	[[nodiscard]] std::unordered_map<char, std::shared_ptr<ICommand>>
 	get_input_config() const noexcept override;
 
 private:
-	const std::shared_ptr<IWindow> &_window;
-	const std::shared_ptr<IScene> &_scene;
-	const std::shared_ptr<ICursorController> &_cursor_controller;
+	std::shared_ptr<IWindow> _window;
+	std::shared_ptr<IScene> _scene;
+	std::shared_ptr<ICursorController> _cursor_controller;
+	std::shared_ptr<IStatusLine> _statusline;
+	std::shared_ptr<IGenerationTracker> _generation_tracker;
+	std::shared_ptr<IStatusUpdater> _status_updater;
 };
diff --git a/src/game/generation_tracker.cpp b/src/game/generation_tracker.cpp
new file mode 100644
index 0000000..0e137cb
--- /dev/null
+++ b/src/game/generation_tracker.cpp
@@ -0,0 +1,18 @@
+#include "generation_tracker.hpp"
+
+GenerationTracker::GenerationTracker(bool is_paused) noexcept : _is_paused(is_paused) {}
+
+uint32_t GenerationTracker::get_current_generation() const noexcept
+{
+	return _current_generation;
+}
+
+bool GenerationTracker::get_is_paused() const noexcept
+{
+	return _is_paused;
+}
+
+void GenerationTracker::set_is_paused(bool is_paused) noexcept
+{
+	_is_paused = is_paused;
+}
diff --git a/src/game/generation_tracker.hpp b/src/game/generation_tracker.hpp
new file mode 100644
index 0000000..0e59751
--- /dev/null
+++ b/src/game/generation_tracker.hpp
@@ -0,0 +1,22 @@
+#pragma once
+
+#include "interfaces/generation_tracker.hpp"
+
+#include <cstdint>
+
+class GenerationTracker : public IGenerationTracker
+{
+public:
+	explicit GenerationTracker(bool is_paused) noexcept;
+
+	[[nodiscard]] uint32_t get_current_generation() const noexcept override;
+
+	[[nodiscard]] bool get_is_paused() const noexcept override;
+
+	void set_is_paused(bool is_paused) noexcept override;
+
+private:
+	uint32_t _current_generation = 0U;
+
+	bool _is_paused;
+};
diff --git a/src/game/status_updater.cpp b/src/game/status_updater.cpp
new file mode 100644
index 0000000..18c535e
--- /dev/null
+++ b/src/game/status_updater.cpp
@@ -0,0 +1,25 @@
+#include "status_updater.hpp"
+
+#include <fmt/core.h>
+#include <utility>
+
+StatusUpdater::StatusUpdater(
+	std::shared_ptr<IStatusLine> statusline,
+	std::shared_ptr<IGenerationTracker> generation_tracker) noexcept
+	: _statusline(std::move(statusline)),
+	  _generation_tracker(std::move(generation_tracker))
+{
+}
+
+void StatusUpdater::update(const Vector2 &context) noexcept
+{
+	_statusline->set_status(
+		StatusLineSection::A,
+		fmt::format("X: {}    Y {}", context.get_x(), context.get_y()));
+
+	_statusline->set_status(
+		StatusLineSection::B,
+		fmt::format("Paused: {}    Generation: {}",
+					_generation_tracker->get_is_paused() ? "yes" : "no",
+					_generation_tracker->get_current_generation()));
+}
diff --git a/src/game/status_updater.hpp b/src/game/status_updater.hpp
new file mode 100644
index 0000000..3b76d3b
--- /dev/null
+++ b/src/game/status_updater.hpp
@@ -0,0 +1,24 @@
+#pragma once
+
+#include "interfaces/generation_tracker.hpp"
+#include "interfaces/status_updater.hpp"
+#include "interfaces/statusline.hpp"
+#include "interfaces/subscriber.hpp"
+
+#include "engine/data/vector2.hpp"
+
+#include <memory>
+
+class StatusUpdater : public IStatusUpdater
+{
+public:
+	explicit StatusUpdater(
+		std::shared_ptr<IStatusLine> statusline,
+		std::shared_ptr<IGenerationTracker> generation_tracker) noexcept;
+
+	void update(const Vector2 &context) noexcept override;
+
+private:
+	std::shared_ptr<IStatusLine> _statusline;
+	std::shared_ptr<IGenerationTracker> _generation_tracker;
+};
diff --git a/src/game/statusline.cpp b/src/game/statusline.cpp
new file mode 100644
index 0000000..377fa75
--- /dev/null
+++ b/src/game/statusline.cpp
@@ -0,0 +1,102 @@
+#include "statusline.hpp"
+
+#include "engine/escape.hpp"
+#include "util/color.hpp"
+
+#include <iostream>
+#include <string>
+#include <utility>
+
+StatusLine::StatusLine(std::shared_ptr<ICursorController> cursor_controller,
+					   std::shared_ptr<IWindow> window) noexcept
+	: _cursor_controller(std::move(cursor_controller)), _window(std::move(window))
+{
+	constexpr uint32_t SECTION_A_LENGTH = 20;
+	constexpr uint32_t SECTION_B_LENGTH = 15;
+
+	_sections_lengths[StatusLineSection::A] = SECTION_A_LENGTH;
+	_sections_lengths[StatusLineSection::B] = SECTION_B_LENGTH;
+}
+
+void StatusLine::initialize_background() noexcept
+{
+	const auto previous_position = _move_to_statusline(0);
+
+	auto background_color = get_background_esc_seq(STATUSBAR_COLOR);
+
+	fmt::print("{}{}", background_color, std::string(_window->size().get_width(), ' '));
+	fmt::print(RESET_ALL_MODES, fmt::arg("esc", ESC));
+
+	_move_back(previous_position);
+}
+
+void StatusLine::set_status(StatusLineSection section,
+							const std::string_view &str) noexcept
+{
+	_clear_section(section);
+
+	int32_t section_start = _get_section_start_x(section);
+
+	const auto previous_position = _move_to_statusline(section_start);
+
+	auto background_color = get_background_esc_seq(STATUSBAR_COLOR);
+
+	fmt::print("{}{}", background_color, str);
+	fmt::print(RESET_ALL_MODES, fmt::arg("esc", ESC));
+
+	_move_back(previous_position);
+}
+
+Vector2 StatusLine::_move_to_statusline(int32_t x) noexcept
+{
+	const auto previous_position = _cursor_controller->where();
+
+	const auto window_size = _window->size();
+
+	_cursor_controller->hide();
+
+	auto window_height = static_cast<Vector2::Value>(window_size.get_height());
+
+	_cursor_controller->move_to(Vector2({.x = x, .y = window_height}), true);
+
+	return previous_position;
+}
+
+void StatusLine::_move_back(Vector2 previous_position) noexcept
+{
+	_cursor_controller->move_to(previous_position, true);
+	_cursor_controller->show();
+}
+
+int32_t StatusLine::_get_section_start_x(StatusLineSection section) const noexcept
+{
+	int32_t section_start = 0;
+
+	auto section_index = static_cast<int32_t>(section);
+
+	while (section_index > 0)
+	{
+		section_start += static_cast<int32_t>(
+			_sections_lengths.at(StatusLineSection(section_index - 1)));
+
+		section_index--;
+	}
+
+	return section_start;
+}
+
+void StatusLine::_clear_section(StatusLineSection section) noexcept
+{
+	auto section_start = _get_section_start_x(section);
+
+	const auto previous_position = _move_to_statusline(section_start);
+
+	auto background_color = get_background_esc_seq(STATUSBAR_COLOR);
+
+	auto section_length = _sections_lengths.at(section);
+
+	fmt::print("{}{}", background_color, std::string(section_length, ' '));
+	fmt::print(RESET_ALL_MODES, fmt::arg("esc", ESC));
+
+	_move_back(previous_position);
+}
diff --git a/src/game/statusline.hpp b/src/game/statusline.hpp
new file mode 100644
index 0000000..7db1e0b
--- /dev/null
+++ b/src/game/statusline.hpp
@@ -0,0 +1,41 @@
+#pragma once
+
+#include "interfaces/cursor.hpp"
+#include "interfaces/statusline.hpp"
+#include "interfaces/window.hpp"
+
+#include "engine/data/vector2.hpp"
+
+#include <cstdint>
+#include <fmt/core.h>
+#include <memory>
+#include <string_view>
+#include <unordered_map>
+
+constexpr uint32_t STATUSBAR_COLOR = 0x1A1A1AU;
+
+class StatusLine : public IStatusLine
+{
+public:
+	StatusLine(std::shared_ptr<ICursorController> cursor_controller,
+			   std::shared_ptr<IWindow> window) noexcept;
+
+	void initialize_background() noexcept override;
+
+	void set_status(StatusLineSection section,
+					const std::string_view &str) noexcept override;
+
+private:
+	std::unordered_map<StatusLineSection, uint32_t> _sections_lengths;
+
+	std::shared_ptr<ICursorController> _cursor_controller;
+	std::shared_ptr<IWindow> _window;
+
+	Vector2 _move_to_statusline(int32_t x) noexcept;
+
+	void _move_back(Vector2 previous_position) noexcept;
+
+	int32_t _get_section_start_x(StatusLineSection section) const noexcept;
+
+	void _clear_section(StatusLineSection section) noexcept;
+};
diff --git a/src/interfaces/game.hpp b/src/interfaces/game.hpp
index c99c01f..6836dbd 100644
--- a/src/interfaces/game.hpp
+++ b/src/interfaces/game.hpp
@@ -11,9 +11,11 @@
 class IGame
 {
 public:
-	virtual ~IGame() = default;
+	virtual ~IGame() noexcept = default;
 
-	virtual void on_start() = 0;
+	virtual void on_start() noexcept = 0;
+
+	virtual void on_update() noexcept = 0;
 
 	virtual void on_exit() const noexcept = 0;
 
diff --git a/src/interfaces/generation_tracker.hpp b/src/interfaces/generation_tracker.hpp
new file mode 100644
index 0000000..135af00
--- /dev/null
+++ b/src/interfaces/generation_tracker.hpp
@@ -0,0 +1,18 @@
+#pragma once
+
+#include <cstdint>
+#include <memory>
+
+class IGenerationTracker
+{
+public:
+	virtual ~IGenerationTracker() noexcept = default;
+
+	[[nodiscard]] virtual uint32_t get_current_generation() const noexcept = 0;
+
+	[[nodiscard]] virtual bool get_is_paused() const noexcept = 0;
+
+	virtual void set_is_paused(bool is_paused) noexcept = 0;
+};
+
+using IGenerationTrackerFactory = std::shared_ptr<IGenerationTracker> (*)(bool is_paused);
diff --git a/src/interfaces/scene.hpp b/src/interfaces/scene.hpp
index 0443d41..3b5e037 100644
--- a/src/interfaces/scene.hpp
+++ b/src/interfaces/scene.hpp
@@ -15,8 +15,6 @@ public:
 
 	virtual void leave() noexcept = 0;
 
-	virtual void write_status(const std::string_view &str) noexcept = 0;
-
 	[[nodiscard]] virtual const std::shared_ptr<IMatrix<std::string_view>> &
 	get_matrix() const noexcept = 0;
 };
diff --git a/src/interfaces/status_updater.hpp b/src/interfaces/status_updater.hpp
new file mode 100644
index 0000000..ccfb2db
--- /dev/null
+++ b/src/interfaces/status_updater.hpp
@@ -0,0 +1,19 @@
+#pragma once
+
+#include "interfaces/generation_tracker.hpp"
+#include "interfaces/statusline.hpp"
+#include "interfaces/subscriber.hpp"
+
+#include "engine/data/vector2.hpp"
+
+#include <memory>
+
+class IStatusUpdater : public ISubscriber<Vector2>
+{
+public:
+	void update(const Vector2 &context) noexcept override = 0;
+};
+
+using IStatusUpdaterFactory = std::shared_ptr<IStatusUpdater> (*)(
+	const std::shared_ptr<IStatusLine> &statusline,
+	const std::shared_ptr<IGenerationTracker> &generation_tracker);
diff --git a/src/interfaces/statusline.hpp b/src/interfaces/statusline.hpp
new file mode 100644
index 0000000..00da99b
--- /dev/null
+++ b/src/interfaces/statusline.hpp
@@ -0,0 +1,27 @@
+#pragma once
+
+#include "interfaces/cursor.hpp"
+#include "interfaces/window.hpp"
+
+#include <string_view>
+
+enum StatusLineSection
+{
+	A,
+	B
+};
+
+class IStatusLine
+{
+public:
+	virtual ~IStatusLine() noexcept = default;
+
+	virtual void initialize_background() noexcept = 0;
+
+	virtual void set_status(StatusLineSection section,
+							const std::string_view &str) noexcept = 0;
+};
+
+using IStatusLineFactory = std::shared_ptr<IStatusLine> (*)(
+	const std::shared_ptr<ICursorController> &cursor_controller,
+	const std::shared_ptr<IWindow> &window);