XQueryDeviceState(3)						    X FUNCTIONS 					      XQueryDeviceState(3)

NAME

       XQueryDeviceState - query the state of an extension input device.

SYNTAX

       int XQueryDeviceState(Display *display, XDevice *device);

ARGUMENTS

       display	   Specifies the connection to the X server.

       device	   Specifies the device whose state is to be queried.

DESCRIPTION

       The  XQueryDeviceState  request	queries  the  state of an input device.  The current state of keys and buttons (up or down), and valuators
       (current value) on the device is reported by this request.  Each key or button is represented by a bit in the XDeviceState  structure  that
       is  returned.   Valuators  on  the  device report 0 if they are reporting relative information, and the current value if they are reporting
       absolute information.

       XQueryDeviceState can generate a BadDevice error.

STRUCTURES

       The XDeviceState structure contains:

       typedef struct {
	    XID device_id;
	    int num_classes;
	    XInputClass *data;
       } XDeviceState;

       The XValuatorState structure contains:

       typedef struct {
	    unsigned char class;
	    unsigned char length;
	    unsigned char num_valuators;
	    unsigned char mode;
	    int *valuators;
       } XValuatorState;

       The XKeyState structure contains:

       typedef struct {
	    unsigned char class;
	    unsigned char length;
	    short	  num_keys;
	    char keys[32];
       } XKeyState;

       The XButtonState structure contains:

       typedef struct {
	    unsigned char class;
	    unsigned char length;
	    short	  num_buttons;
	    char buttons[32];
       } XButtonState;

DIAGNOSTICS

       BadDevice   An invalid device was specified.  The specified device does not exist or has not been opened by this client	via  XOpenInputDe-
		   vice.   This  error	may  also occur if some other client has caused the specified device to become the X keyboard or X pointer
		   device via the XChangeKeyboardDevice or XChangePointerDevice requests.

SEE ALSO

       Programming with Xlib

X Version 11							    libXi 1.2.1 					      XQueryDeviceState(3)