refactor: add termios abstraction

4 files changed, 199 insertions, 24 deletions

diff --git a/src/engine/graphics/scene.cpp b/src/engine/graphics/scene.cpp
index 7c23c7d..8ec8ddf 100644
--- a/src/engine/graphics/scene.cpp
+++ b/src/engine/graphics/scene.cpp
@@ -1,13 +1,13 @@
 #include "scene.hpp"
 
+#include <cstdint>
 #include <fmt/core.h>
+#include <iostream>
 #include <sys/ioctl.h>
-#include <termios.h>
 #include <unistd.h>
-#include <cstdint>
-#include <iostream>
 
 #include "engine/escape.hpp"
+#include "engine/io/terminal.hpp"
 
 class IComponent;
 
@@ -19,7 +19,7 @@ Scene::Scene(const IMatrixFactory<MatrixElement> &matrix_factory) noexcept
 
 void Scene::enter() noexcept
 {
-	if (_is_shown || _original_termios != nullptr)
+	if (_is_shown)
 	{
 		return;
 	}
@@ -28,30 +28,22 @@ void Scene::enter() noexcept
 	fmt::print(ENABLE_ALT_BUFFER, fmt::arg("esc", ESC));
 	std::cout.flush();
 
-	// Create a backup of the current terminal state
-	_original_termios = std::make_shared<termios>();
-	tcgetattr(STDIN_FILENO, _original_termios.get());
+	_original_terminal_state = get_terminal_state(STDIN_FILENO);
 
-	auto new_termios = termios(*_original_termios);
+	auto new_terminal_state = TerminalState(_original_terminal_state);
 
-	// Set the local mode flags of the new termios structure
-	//
-	// The following flags are disabled:
-	// ECHO   - Echoing input characters
-	// ICANON - Canonical mode (line by line input)
-	// ISIG   - Generate the corresponding signals for the characters
-	//			INTR, QUIT, SUSP and DSUSP
-	new_termios.c_lflag &= static_cast<std::uint32_t>(~(ECHO | ICANON | ISIG));
+	new_terminal_state.set_local_mode_flag(TerminalLocalModeFlag::echo, false);
+	new_terminal_state.set_local_mode_flag(TerminalLocalModeFlag::icanon, false);
+	new_terminal_state.set_local_mode_flag(TerminalLocalModeFlag::isig, false);
 
-	// Set a new terminal state
-	tcsetattr(STDIN_FILENO, TCSAFLUSH, &new_termios);
+	set_terminal_state(STDIN_FILENO, new_terminal_state);
 
 	_is_shown = true;
 }
 
 void Scene::leave() noexcept
 {
-	if (!_is_shown || _original_termios == nullptr)
+	if (!_is_shown)
 	{
 		return;
 	}
@@ -60,10 +52,9 @@ void Scene::leave() noexcept
 	fmt::print(DISABLE_ALT_BUFFER, fmt::arg("esc", ESC));
 	std::cout.flush();
 
-	// Restore the original terminal state
-	tcsetattr(STDIN_FILENO, TCSAFLUSH, _original_termios.get());
+	set_terminal_state(STDIN_FILENO, _original_terminal_state);
 
-	_original_termios = nullptr;
+	_original_terminal_state = {};
 	_is_shown = false;
 }
 
diff --git a/src/engine/graphics/scene.hpp b/src/engine/graphics/scene.hpp
index 5b52027..da3d990 100644
--- a/src/engine/graphics/scene.hpp
+++ b/src/engine/graphics/scene.hpp
@@ -3,13 +3,13 @@
 #include <fmt/core.h>
 #include <memory>
 #include <string_view>
-#include <termios.h>
 #include <utility>
 #include <vector>
 #include <yacppdic/auto_wirable.hpp>
 
 #include "engine/data/bounds.hpp"
 #include "engine/data/vector2.hpp"
+#include "engine/io/terminal.hpp"
 #include "interfaces/component.hpp"
 #include "interfaces/matrix.hpp"
 #include "interfaces/scene.hpp"
@@ -47,7 +47,7 @@ private:
 	std::shared_ptr<IMatrix<MatrixElement>> _matrix;
 
 	bool _is_shown;
-	std::shared_ptr<termios> _original_termios = nullptr;
+	TerminalState _original_terminal_state{};
 
 	std::vector<std::pair<std::shared_ptr<IComponent>, Vector2>> _components;
 };
diff --git a/src/engine/io/terminal.cpp b/src/engine/io/terminal.cpp
new file mode 100644
index 0000000..e6d7d3a
--- /dev/null
+++ b/src/engine/io/terminal.cpp
@@ -0,0 +1,54 @@
+#include "terminal.hpp"
+
+TerminalState::TerminalState(termios term_attrs) noexcept : _term_attrs(term_attrs) {}
+
+void TerminalState::set_input_mode_flag(TerminalInputModeFlag flag, bool is_on) noexcept
+{
+	auto flag_num = static_cast<tcflag_t>(flag);
+
+	_term_attrs.c_iflag &= is_on ? flag_num : ~flag_num;
+}
+
+void TerminalState::set_output_mode_flag(TerminalOutputModeFlag flag, bool is_on) noexcept
+{
+	auto flag_num = static_cast<tcflag_t>(flag);
+
+	_term_attrs.c_oflag &= is_on ? flag_num : ~flag_num;
+}
+
+void TerminalState::set_control_mode_flag(
+	TerminalControlModeFlag flag,
+	bool is_on) noexcept
+{
+	auto flag_num = static_cast<tcflag_t>(flag);
+
+	_term_attrs.c_cflag &= is_on ? flag_num : ~flag_num;
+}
+
+void TerminalState::set_local_mode_flag(TerminalLocalModeFlag flag, bool is_on) noexcept
+{
+	auto flag_num = static_cast<tcflag_t>(flag);
+
+	_term_attrs.c_lflag &= is_on ? flag_num : ~flag_num;
+}
+
+auto TerminalState::get_attributes() noexcept -> termios
+{
+	return _term_attrs;
+}
+
+auto get_terminal_state(int term_fd) noexcept -> TerminalState
+{
+	termios term_attrs{};
+
+	tcgetattr(term_fd, &term_attrs);
+
+	return TerminalState(term_attrs);
+}
+
+void set_terminal_state(int term_fd, TerminalState state) noexcept
+{
+	auto state_attrs = state.get_attributes();
+
+	tcsetattr(term_fd, TCSAFLUSH, &state_attrs);
+}
diff --git a/src/engine/io/terminal.hpp b/src/engine/io/terminal.hpp
new file mode 100644
index 0000000..27455bb
--- /dev/null
+++ b/src/engine/io/terminal.hpp
@@ -0,0 +1,130 @@
+#pragma once
+
+#include <termios.h>
+
+enum class TerminalControlModeFlag
+{
+	csize = 0000060,
+	cs5 = 0000000,
+	cs6 = 0000020,
+	cs7 = 0000040,
+	cs8 = 0000060,
+	cstopb = 0000100,
+	cread = 0000200,
+	parenb = 0000400,
+	parodd = 0001000,
+	hupcl = 0002000,
+	clocal = 0004000,
+};
+
+enum class TerminalInputModeFlag
+{
+	ignbrk = 0000001,  // Ignore break condition
+	brkint = 0000002,  // Signal interrupt on break
+	ignpar = 0000004,  // Ignore characters with parity errors
+	parmrk = 0000010,  // Mark parity and framing errors
+	inpck = 0000020,   // Enable input parity check
+	istrip = 0000040,  // Strip = 8,th bit off characters
+	inlcr = 0000100,   // Map NL to CR on input
+	igncr = 0000200,   // Ignore CR
+	icrnl = 0000400,   // Map CR to NL on input
+	iuclc = 0001000,   // Map uppercase characters to lowercase on input (not in POSIX)
+	ixon = 0002000,	   // Enable start/stop output control
+	ixany = 0004000,   // Enable any character to restart output
+	ixoff = 0010000,   // Enable start/stop input control
+	imaxbel = 0020000, // Ring bell when input queue is full (not in POSIX)
+	iutf8 = 0040000,   // Input is UTF8 (not in POSIX)
+};
+
+enum class TerminalOutputModeFlag
+{
+	opost = 0000001,  // Post-process output
+	olcuc = 0000002,  // Map lowercase characters to uppercase on output (not in POSIX)
+	onlcr = 0000004,  // Map NL to CR-NL on output
+	ocrnl = 0000010,  // Map CR to NL on output
+	onocr = 0000020,  // No CR output at column = 0
+	onlret = 0000040, // NL performs CR function
+	ofill = 0000100,  // Use fill characters for delay
+	ofdel = 0000200,  // Fill is DEL
+	nldly = 0000400,  // Select newline delays:
+	nl0 = 0000000,	  // Newline type = 0
+	nl1 = 0000400,	  // Newline type = 1
+	crdly = 0003000,  // Select carriage-return delays:
+	cr0 = 0000000,	  // Carriage-return delay type = 0
+	cr1 = 0001000,	  // Carriage-return delay type = 1
+	cr2 = 0002000,	  // Carriage-return delay type = 2
+	cr3 = 0003000,	  // Carriage-return delay type = 3
+	tabdly = 0014000, // Select horizontal-tab delays:
+	tab0 = 0000000,	  // Horizontal-tab delay type = 0
+	tab1 = 0004000,	  // Horizontal-tab delay type = 1
+	tab2 = 0010000,	  // Horizontal-tab delay type = 2
+	tab3 = 0014000,	  // Expand tabs to spaces
+	bsdly = 0020000,  // Select backspace delays:
+	bs0 = 0000000,	  // Backspace-delay type = 0
+	bs1 = 0020000,	  // Backspace-delay type = 1
+	ffdly = 0100000,  // Select form-feed delays:
+	ff0 = 0000000,	  // Form-feed delay type = 0
+	ff1 = 0100000,	  // Form-feed delay type = 1
+	vtdly = 0040000,  // Select vertical-tab delays:
+	vt0 = 0000000,	  // Vertical-tab delay type = 0
+	vt1 = 0040000,	  // Vertical-tab delay type = 1
+	xtabs = 0014000,
+};
+
+enum class TerminalLocalModeFlag
+{
+	isig = 0000001, // When any of the characters INTR, QUIT, SUSP, or DSUSP are received,
+					// generate the corresponding signal
+	icanon = 0000002, // Canonical input
+	xcase = 0000004,
+	echo = 0000010,	   // Echo input characters
+	echoe = 0000020,   // Echo erase character as error-correcting backspace
+	echok = 0000040,   // Echo KILL
+	echonl = 0000100,  // Echo NL
+	noflsh = 0000200,  // Disable flush after interrupt or quit
+	tostop = 0000400,  // Send SIGTTOU for background output
+	echoctl = 0001000, /* If ECHO is also set, terminal special characters
+					other than TAB, NL, START, and STOP are echoed as
+					^X, where X is the character with ASCII code = 0,x40
+					greater than the special character
+					(not in POSIX) */
+	echoprt = 0002000, /* If ICANON and ECHO are also set, characters are
+					printed as they are being erased
+					(not in POSIX) */
+	echoke = 0004000,  /* If ICANON is also set, KILL is echoed by erasing
+				   each character on the line, as specified by ECHOE
+				   and ECHOPRT (not in POSIX) */
+	flusho = 0010000,  /* Output is being flushed  This flag is toggled by
+				   typing the DISCARD character (not in POSIX) */
+	pendin = 0040000,  /* All characters in the input queue are reprinted
+				   when the next character is read
+				   (not in POSIX) */
+	iexten = 0100000,  // Enable implementation-defined input processing
+	extproc = 0200000,
+};
+
+class TerminalState
+{
+public:
+	TerminalState() = default;
+
+	explicit TerminalState(termios term_attrs) noexcept;
+
+	void set_input_mode_flag(TerminalInputModeFlag flag, bool is_on) noexcept;
+
+	void set_output_mode_flag(TerminalOutputModeFlag flag, bool is_on) noexcept;
+
+	void set_control_mode_flag(TerminalControlModeFlag flag, bool is_on) noexcept;
+
+	void set_local_mode_flag(TerminalLocalModeFlag flag, bool is_on) noexcept;
+
+	auto get_attributes() noexcept -> termios;
+
+private:
+	termios _term_attrs;
+};
+
+auto get_terminal_state(int term_fd) noexcept -> TerminalState;
+
+void set_terminal_state(int term_fd, TerminalState state) noexcept;
+