Windows API Reference: Input

This section provides documentation for Windows API functions related to handling user input, including keyboard, mouse, and touch input.

Core Input Functions

`GetKeyState`

Retrieves the status of a specified key on the keyboard.

SHORT GetKeyState( int nVirtKey );

Parameters:

nVirtKey: Specifies one of the virtual-key codes. For a list of virtual-key codes, see Virtual-Key Codes.

Return Value:

The return value specifies the status of the specified virtual key, as well as the status of the assembler for each of the controls keys. If the most significant bit of the return value is set, the key is down; otherwise, the key is up.

This function retrieves the status of a keyboard message that has already been placed in the calling thread's message queue.

`SetCursorPos`

Moves the cursor to the specified position on the screen.

BOOL SetCursorPos( int X, int Y );

Parameters:

X: The new horizontal position of the cursor, in screen coordinates.
Y: The new vertical position of the cursor, in screen coordinates.

Return Value:

Nonzero if successful; otherwise, zero.

`GetMouseButtonsState`

Retrieves the current state of the mouse buttons.

DWORD GetMouseButtonsState();

Return Value:

A bitmask indicating which mouse buttons are pressed. Possible values include:

MK_LBUTTON: Left mouse button is down.
MK_RBUTTON: Right mouse button is down.
MK_MBUTTON: Middle mouse button is down.
MK_SHIFT: SHIFT key is down.
MK_CONTROL: CTRL key is down.

Advanced Input Mechanisms

`RegisterTouchWindow`

Registers a window for touch input.

BOOL RegisterTouchWindow( HWND hwnd, ULONG ulFlags );

Parameters:

hwnd: A handle to the window to register.
ulFlags: Reserved. Must be zero.

Return Value:

TRUE if the function succeeds; otherwise, FALSE.

This function is essential for enabling multi-touch support on a window.

`GetRawInputDeviceInfo`

Retrieves information about the specified raw input device.

UINT GetRawInputDeviceInfo( HANDLE hDevice, UINT uiCommand, LPVOID pData );

Parameters:

hDevice: Handle to the raw input device.
uiCommand: The information to retrieve. See Raw Input Commands.
pData: Pointer to a buffer that receives the device information.

Related Concepts

Proper handling of user input is critical for creating responsive and user-friendly Windows applications. Always consider accessibility and different input methods.