Ler eventos de buffer de entrada

A função ReadConsoleInput pode ser usada para acesso direto ao buffer de entrada de um console. Quando um console é criado, a entrada do mouse é habilitada e a entrada da janela é desabilitada. Para garantir que o processo receba todos os tipos de eventos, este exemplo usa a função SetConsoleMode para habilitar as entradas da janela e do mouse. Em seguida, ocorre um loop que lê e manipula 100 eventos de entrada do console. Por exemplo, a mensagem "Evento do teclado" é exibida quando o usuário pressiona uma tecla e a mensagem "Evento do mouse" é exibida quando o usuário interage com o mouse.

#include <windows.h>
#include <stdio.h>

HANDLE hStdin;
DWORD fdwSaveOldMode;

VOID ErrorExit(LPCSTR);
VOID KeyEventProc(KEY_EVENT_RECORD);
VOID MouseEventProc(MOUSE_EVENT_RECORD);
VOID ResizeEventProc(WINDOW_BUFFER_SIZE_RECORD);

int main(VOID)
{
    DWORD cNumRead, fdwMode, i;
    INPUT_RECORD irInBuf[128];
    int counter=0;

    // Get the standard input handle.

    hStdin = GetStdHandle(STD_INPUT_HANDLE);
    if (hStdin == INVALID_HANDLE_VALUE)
        ErrorExit("GetStdHandle");

    // Save the current input mode, to be restored on exit.

    if (! GetConsoleMode(hStdin, &fdwSaveOldMode) )
        ErrorExit("GetConsoleMode");

    // Enable the window and mouse input events.

    fdwMode = ENABLE_WINDOW_INPUT | ENABLE_MOUSE_INPUT;
    if (! SetConsoleMode(hStdin, fdwMode) )
        ErrorExit("SetConsoleMode");

    // Loop to read and handle the next 100 input events.

    while (counter++ <= 100)
    {
        // Wait for the events.

        if (! ReadConsoleInput(
                hStdin,      // input buffer handle
                irInBuf,     // buffer to read into
                128,         // size of read buffer
                &cNumRead) ) // number of records read
            ErrorExit("ReadConsoleInput");

        // Dispatch the events to the appropriate handler.

        for (i = 0; i < cNumRead; i++)
        {
            switch(irInBuf[i].EventType)
            {
                case KEY_EVENT: // keyboard input
                    KeyEventProc(irInBuf[i].Event.KeyEvent);
                    break;

                case MOUSE_EVENT: // mouse input
                    MouseEventProc(irInBuf[i].Event.MouseEvent);
                    break;

                case WINDOW_BUFFER_SIZE_EVENT: // scrn buf. resizing
                    ResizeEventProc( irInBuf[i].Event.WindowBufferSizeEvent );
                    break;

                case FOCUS_EVENT:  // disregard focus events

                case MENU_EVENT:   // disregard menu events
                    break;

                default:
                    ErrorExit("Unknown event type");
                    break;
            }
        }
    }

    // Restore input mode on exit.

    SetConsoleMode(hStdin, fdwSaveOldMode);

    return 0;
}

VOID ErrorExit (LPSTR lpszMessage)
{
    fprintf(stderr, "%s\n", lpszMessage);

    // Restore input mode on exit.

    SetConsoleMode(hStdin, fdwSaveOldMode);

    ExitProcess(0);
}

VOID KeyEventProc(KEY_EVENT_RECORD ker)
{
    printf("Key event: ");

    if(ker.bKeyDown)
        printf("key pressed\n");
    else printf("key released\n");
}

VOID MouseEventProc(MOUSE_EVENT_RECORD mer)
{
#ifndef MOUSE_HWHEELED
#define MOUSE_HWHEELED 0x0008
#endif
    printf("Mouse event: ");

    switch(mer.dwEventFlags)
    {
        case 0:

            if(mer.dwButtonState == FROM_LEFT_1ST_BUTTON_PRESSED)
            {
                printf("left button press \n");
            }
            else if(mer.dwButtonState == RIGHTMOST_BUTTON_PRESSED)
            {
                printf("right button press \n");
            }
            else
            {
                printf("button press\n");
            }
            break;
        case DOUBLE_CLICK:
            printf("double click\n");
            break;
        case MOUSE_HWHEELED:
            printf("horizontal mouse wheel\n");
            break;
        case MOUSE_MOVED:
            printf("mouse moved\n");
            break;
        case MOUSE_WHEELED:
            printf("vertical mouse wheel\n");
            break;
        default:
            printf("unknown\n");
            break;
    }
}

VOID ResizeEventProc(WINDOW_BUFFER_SIZE_RECORD wbsr)
{
    printf("Resize event\n");
    printf("Console screen buffer is %d columns by %d rows.\n", wbsr.dwSize.X, wbsr.dwSize.Y);
}