XQueryDeviceState(3X11) 												   XQueryDeviceState(3X11)

NAME

       XQueryDeviceState - query the state of an extension input device.

SYNOPSIS

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

ARGUMENTS

       Specifies the connection to the X server.  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

       An invalid device was specified.  The specified device does not exist or has not been opened by this  client  via  XOpenInputDevice.   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 XChangeKey-
       boardDevice or XChangePointerDevice requests.

SEE ALSO

       Programming with Xlib

															   XQueryDeviceState(3X11)