ReadConsoleInput example

ReadConsoleInput.cpp

#define WIN32_LEAN_AND_MEAN
#define NOMINMAX
#include <Windows.h>
#include <cassert>
#include <cstdio>

namespace
{
    void PrintLastError(const char* name)
    {
        std::fprintf(stderr, "%s failed (%d)\n", name, GetLastError());
    }
} // namespace

int main()
{
    auto hStdInput = GetStdHandle(STD_INPUT_HANDLE);
    if (hStdInput == INVALID_HANDLE_VALUE)
    {
        PrintLastError("GetStdHandle");
        return 1;
    }

    // TODO: In production, the previous mode should be restored.
    constexpr DWORD consoleMode =
        ENABLE_PROCESSED_INPUT | // enable Ctrl+C
        // ENABLE_LINE_INPUT |
        // ENABLE_ECHO_INPUT |
        ENABLE_WINDOW_INPUT |
        ENABLE_MOUSE_INPUT |
        // ENABLE_INSERT_MODE |
        // // ENABLE_QUICK_EDIT_MODE |
        // ENABLE_EXTENDED_FLAGS |
        // ENABLE_VIRTUAL_TERMINAL_INPUT
        0;

    if (!SetConsoleMode(hStdInput, consoleMode))
    {
        PrintLastError("SetConsoleMode");
        return 1;
    }

    while (true)
    {
        INPUT_RECORD r;
        DWORD n;
        if (!ReadConsoleInputW(hStdInput, &r, 1, &n))
        {
            PrintLastError("ReadConsoleInputW");
            return 1;
        }

        assert(n == 1);

        switch (r.EventType)
        {
        case KEY_EVENT:
        {
            // In a pseudo console, a key down event is immediately followed by a key up event, which is very natural since a PTY does not have the concept of "key up".
            const auto& e = r.Event.KeyEvent;
            std::printf(
                "KeyEvent %d %d %d %d %d %d\n",
                e.bKeyDown,
                e.dwControlKeyState,
                e.wVirtualKeyCode,
                e.wVirtualScanCode,
                e.wRepeatCount,
                e.uChar.UnicodeChar);
            break;
        }

        case MENU_EVENT:
            // > These events are used internally and should be ignored.
            break;

        case MOUSE_EVENT:
        {
            // NOTE: need to disable the quick edit mode to receive mouse events
            const auto& e = r.Event.MouseEvent;
            std::printf(
                "MouseEvent %d %d %d (%d, %d)\n",
                e.dwButtonState,
                e.dwControlKeyState,
                e.dwEventFlags,
                e.dwMousePosition.X,
                e.dwMousePosition.Y);
            break;
        }

        case FOCUS_EVENT:
            // > These events are used internally and should be ignored.
            break;

        case WINDOW_BUFFER_SIZE_EVENT:
        {
            const auto& e = r.Event.WindowBufferSizeEvent;
            std::printf(
                "WindowBufferSizeEvent (%d, %d)\n",
                e.dwSize.X,
                e.dwSize.Y);
            break;
        }

        default:
            std::printf("Unknown Event %d\n", r.EventType);
            break;
        }
    }
}