feat(config): add RAII guard for raw mode

Sample/App/Source/Main.cpp

@@ -1,5 +1,7 @@
 #include <ctui_c.h>
 
+#include "ctui_raw_mode.h"
+
 #ifdef _WIN32
 #include <windows.h>
 #endif
@@ -13,7 +15,8 @@ int main() {
     SetConsoleCP(CP_UTF8);
 #endif
 
-    enable_raw_mode();
+    RawModeGuard rmg;
+
     screen->config();
 
     auto root = screen->make_child<VStack>(

Source/ctui.h

@@ -9,3 +9,4 @@
 #include "Widgets/Container/ctui_container_vstack.h"
 #include "Widgets/Container/ctui_container_screen.h"
 #include "ctui_utf8.h"
+#include "ctui_raw_mode.h"

Source/ctui_config.cpp

@@ -7,51 +7,12 @@
 #include <windows.h>
 #include <conio.h>
 #else
-#include <termios.h>
 #include <unistd.h>
 #include <sys/ioctl.h>
-#include <stdio.h>
 #endif
 
-namespace ctui {
-    bool raw_mode = false;
-
-
-    void enable_raw_mode() {
-#ifdef _WIN32
-        HANDLE hStdin = GetStdHandle(STD_INPUT_HANDLE);
-        DWORD mode;
-        GetConsoleMode(hStdin, &mode);
-        SetConsoleMode(hStdin, mode & ~(ENABLE_LINE_INPUT | ENABLE_ECHO_INPUT));
-        HANDLE hOut = GetStdHandle(STD_OUTPUT_HANDLE);
-        GetConsoleMode(hOut, &mode);
-        SetConsoleMode(hOut, mode | ENABLE_VIRTUAL_TERMINAL_PROCESSING);
-#else
-        termios t;
-        tcgetattr(STDIN_FILENO, &t);
-        t.c_lflag &= ~(ICANON | ECHO | IXON);
-        tcsetattr(STDIN_FILENO, TCSANOW, &t);
-#endif
-        std::ios::sync_with_stdio(false);
-    	raw_mode = true;
-        std::cout << "\033[2J\033[H";
-    }
-
-    void disable_raw_mode() {
-#ifdef _WIN32
-        HANDLE hStdin = GetStdHandle(STD_INPUT_HANDLE);
-        DWORD mode;
-        GetConsoleMode(hStdin, &mode);
-        SetConsoleMode(hStdin, mode | ENABLE_LINE_INPUT | ENABLE_ECHO_INPUT);
-#else
-        termios t;
-        tcgetattr(STDIN_FILENO, &t);
-        t.c_lflag |= (ICANON | ECHO);
-        tcsetattr(STDIN_FILENO, TCSANOW, &t);
-#endif
-        raw_mode = false;
-    }
-
+namespace ctui
+{
     std::pair<int, int> get_win_size() {
 #ifdef _WIN32
         CONSOLE_SCREEN_BUFFER_INFO csbi;

Source/ctui_config.h

@@ -2,8 +2,5 @@
 #include <utility>
 
 namespace ctui {
-    extern bool raw_mode;
-    void enable_raw_mode();
-    void disable_raw_mode();
     std::pair<int, int> get_win_size();
 }

Source/ctui_raw_mode.cpp

@@ -0,0 +1,61 @@
+#include "pch.h"
+
+#include "ctui_raw_mode.h"
+
+namespace ctui
+{
+    RawModeGuard::RawModeGuard()
+    {
+#ifdef _WIN32
+        _stdin = GetStdHandle(STD_INPUT_HANDLE);
+        _stdout = GetStdHandle(STD_OUTPUT_HANDLE);
+
+        // GetConsoleMode fails if the handle is invalid or redirected (e.g. stdin/stdout
+        // piped to a file). Without this check, _original_*_mode stays uninitialized and
+        // we'd later restore garbage in the destructor.
+        if (!GetConsoleMode(_stdin, &_original_stdin_mode))
+            throw std::system_error(GetLastError(), std::system_category(), "GetConsoleMode (stdin) failed");
+        if (!GetConsoleMode(_stdout, &_original_stdout_mode))
+            throw std::system_error(GetLastError(), std::system_category(), "GetConsoleMode (stdout) failed");
+
+        DWORD stdin_mode = _original_stdin_mode;
+        stdin_mode &= ~(ENABLE_LINE_INPUT | ENABLE_ECHO_INPUT);
+        SetConsoleMode(_stdin, stdin_mode);
+
+        DWORD stdout_mode = _original_stdout_mode;
+        stdout_mode |= ENABLE_VIRTUAL_TERMINAL_PROCESSING;
+        SetConsoleMode(_stdout, stdout_mode);
+#else
+        // Same reasoning as GetConsoleMode above: tcgetattr fails for non-TTY stdin
+        // (redirected/piped), and leaves _original untouched on failure.
+        if (tcgetattr(STDIN_FILENO, &_original) != 0)
+            throw std::system_error(errno, std::generic_category(), "tcgetattr failed");
+
+        termios raw = _original;
+        raw.c_lflag &= ~(ICANON | ECHO);
+        raw.c_iflag &= ~IXON;
+
+        tcsetattr(STDIN_FILENO, TCSANOW, &raw);
+#endif
+
+        // TODO: Move code to main loop as soon as it exists.
+        std::ios::sync_with_stdio(false);
+        std::cout << "\033[?1049h\033[2J\033[H";
+    }
+
+    RawModeGuard::~RawModeGuard()
+    {
+        // Must run *before* restoring the console mode below: if the original stdout
+        // mode didn't have ENABLE_VIRTUAL_TERMINAL_PROCESSING (the common case), the
+        // escape sequence would no longer be interpreted once we restore it, and the
+        // terminal would be stuck in the alternate screen buffer.
+        std::cout << "\033[?1049l"; // TODO: move to main loop
+
+#ifdef _WIN32
+        SetConsoleMode(_stdin, _original_stdin_mode);
+        SetConsoleMode(_stdout, _original_stdout_mode);
+#else
+        tcsetattr(STDIN_FILENO, TCSANOW, &_original);
+#endif
+    }
+}

Source/ctui_raw_mode.h

@@ -0,0 +1,33 @@
+#pragma once
+
+#ifdef _WIN32
+#include <windows.h>
+#else
+#include <termios.h>
+#include <unistd.h>
+#endif
+
+namespace ctui
+{
+	class RawModeGuard
+	{
+		// Original Terminal State
+#ifdef _WIN32
+		HANDLE _stdin;
+		HANDLE _stdout;
+
+		DWORD _original_stdin_mode;
+		DWORD _original_stdout_mode;
+#else
+		termios _original;
+#endif
+	public:
+		RawModeGuard();
+		~RawModeGuard();
+
+		RawModeGuard(const RawModeGuard&) = delete;
+		RawModeGuard& operator=(const RawModeGuard&) = delete;
+		RawModeGuard(RawModeGuard&&) = delete;
+		RawModeGuard& operator=(RawModeGuard&&) = delete;
+	};
+}