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XQueryDeviceState(3X11)
X11R6
NAME
  XQueryDeviceState - query the state of an extension input device.

SYNOPSIS
  XQueryDeviceState(display, device)
	  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 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 XChangeKeyboardDevice or XChangePointerDevice requests.

SEE ALSO
  Programming with Xlib

Index for Section 3X11

Alphabetical listing for X

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