From eb66598c326862fd9dfc1899be4eac93f81a8023 Mon Sep 17 00:00:00 2001
From: HampusM <hampus@hampusmat.com>
Date: Wed, 8 Jun 2022 19:23:55 +0200
Subject: fix: prevent A, B, C & D from being interpreted as arrow keys

---
 src/engine/engine.cpp     |  2 --
 src/engine/keycodes.hpp   | 15 +++++++++++
 src/engine/user/input.cpp | 65 ++++++++++++++++++++++++++++++++++-------------
 src/engine/user/input.hpp | 13 +++++-----
 4 files changed, 69 insertions(+), 26 deletions(-)
 create mode 100644 src/engine/keycodes.hpp

(limited to 'src/engine')

diff --git a/src/engine/engine.cpp b/src/engine/engine.cpp
index c569c69..ed75394 100644
--- a/src/engine/engine.cpp
+++ b/src/engine/engine.cpp
@@ -76,8 +76,6 @@ void CLIGameEngine::start() noexcept
 			}
 		}
 
-		_user_input_observer->clear_currently_pressed();
-
 		last_update_time = std::chrono::system_clock::now();
 	}
 }
diff --git a/src/engine/keycodes.hpp b/src/engine/keycodes.hpp
new file mode 100644
index 0000000..163df52
--- /dev/null
+++ b/src/engine/keycodes.hpp
@@ -0,0 +1,15 @@
+#pragma once
+
+namespace keycodes
+{
+
+constexpr auto ENTER = 10;
+constexpr auto ESCAPE = 27;
+constexpr auto BACKSPACE = 127;
+
+constexpr auto UP_ARROW = -10;
+constexpr auto DOWN_ARROW = -11;
+constexpr auto RIGHT_ARROW = -12;
+constexpr auto LEFT_ARROW = -13;
+
+} // namespace keycodes
diff --git a/src/engine/user/input.cpp b/src/engine/user/input.cpp
index cbba143..f0ffbe5 100644
--- a/src/engine/user/input.cpp
+++ b/src/engine/user/input.cpp
@@ -1,9 +1,16 @@
 #include "input.hpp"
 
+#include "engine/keycodes.hpp"
+
 #include <iostream>
 #include <unistd.h>
+#include <unordered_map>
 
-#include <iostream>
+const std::unordered_map<char, char> special_keys_map = {
+	{'A', keycodes::UP_ARROW},
+	{'B', keycodes::DOWN_ARROW},
+	{'C', keycodes::RIGHT_ARROW},
+	{'D', keycodes::LEFT_ARROW}};
 
 void UserInputObserver::listen() noexcept
 {
@@ -16,38 +23,60 @@ void UserInputObserver::listen() noexcept
 			continue;
 		}
 
-		_currently_pressed_mutex.lock();
+		_input_buffer_mutex.lock();
 
-		if (character != _currently_pressed)
-		{
-			_currently_pressed = character;
-		}
+		_input_buffer += character;
 
-		_currently_pressed_mutex.unlock();
+		_input_buffer_mutex.unlock();
 	}
 }
 
-bool UserInputObserver::is_key_pressed(Key key) noexcept
+auto UserInputObserver::get_currently_pressed_key() noexcept -> Key
 {
-	_currently_pressed_mutex.lock();
+	auto input_buffer = _get_input_buffer();
 
-	const auto is_key_pressed = key == _currently_pressed;
+	if (input_buffer.empty())
+	{
+		return 0;
+	}
+
+	auto character = input_buffer.front();
 
-	_currently_pressed_mutex.unlock();
+	// Special treatment for arrow keys
+	if (input_buffer.length() == 3 && character == keycodes::ESCAPE)
+	{
+		const auto arrow_key_code = input_buffer.at(2);
 
-	return is_key_pressed;
+		if (arrow_key_code >= 'A' && arrow_key_code <= 'D')
+		{
+			character = special_keys_map.at(arrow_key_code);
+		}
+
+		input_buffer = input_buffer.substr(2);
+	}
+
+	input_buffer = input_buffer.substr(1);
+	_set_input_buffer(input_buffer);
+
+	return character;
 }
 
-auto UserInputObserver::get_currently_pressed_key() const noexcept -> Key
+auto UserInputObserver::_get_input_buffer() const noexcept -> std::string
 {
-	return _currently_pressed;
+	_input_buffer_mutex.lock();
+
+	auto input_buffer = _input_buffer;
+
+	_input_buffer_mutex.unlock();
+
+	return input_buffer;
 }
 
-void UserInputObserver::clear_currently_pressed() noexcept
+void UserInputObserver::_set_input_buffer(const std::string &input_buffer) noexcept
 {
-	_currently_pressed_mutex.lock();
+	_input_buffer_mutex.lock();
 
-	_currently_pressed = 0;
+	_input_buffer = input_buffer;
 
-	_currently_pressed_mutex.unlock();
+	_input_buffer_mutex.unlock();
 }
diff --git a/src/engine/user/input.hpp b/src/engine/user/input.hpp
index 9f565c1..12c27ee 100644
--- a/src/engine/user/input.hpp
+++ b/src/engine/user/input.hpp
@@ -6,6 +6,7 @@
 
 #include <memory>
 #include <mutex>
+#include <string>
 
 class UserInputObserver
 	: public IUserInputObserver,
@@ -16,13 +17,13 @@ public:
 
 	void listen() noexcept override;
 
-	auto is_key_pressed(Key key) noexcept -> bool override;
+	auto get_currently_pressed_key() noexcept -> Key override;
 
-	[[nodiscard]] auto get_currently_pressed_key() const noexcept -> Key override;
+private:
+	std::string _input_buffer;
+	mutable std::mutex _input_buffer_mutex;
 
-	void clear_currently_pressed() noexcept override;
+	auto _get_input_buffer() const noexcept -> std::string;
 
-private:
-	Key _currently_pressed{};
-	std::mutex _currently_pressed_mutex;
+	void _set_input_buffer(const std::string &input_buffer) noexcept;
 };
-- 
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