XDeviceTimeCoord

XGetDeviceMotionEvents(3X11)	 X FUNCTIONS	 XGetDeviceMotionEvents(3X11)



NAME
       XGetDeviceMotionEvents, XDeviceTimeCoord - get device motion history

SYNTAX
       XDeviceTimeCoord	  *XGetDeviceMotionEvents(Display  *display,  XDevice
	      *device,	Time  start,  Time  stop,  int	*nevents_return,  int
	      *mode_return, int *axis_count_return);

ARGUMENTS
       display	   Specifies the connection to the X server.

       device	   Specifies  the  device  whose  motion  history  is  to  be
		   queried.

       start
       stop	   Specify the time interval in which the events are returned
		   from	 the motion history buffer.  You can pass a timestamp
		   or CurrentTime.

       nevents_return
		   Returns the number  of  events  from	 the  motion  history
		   buffer.

       mode_return Returns the mode of the device (Absolute or Relative).

       axis_count_return
		   Returns the count of axes being reported.

DESCRIPTION
       The  server  may retain the recent history of the device motion and do
       so to a finer  granularity  than	 is  reported  by  DeviceMotionNotify
       events.	 The XGetDeviceMotionEvents request makes this history avail-
       able.

       The XGetDeviceMotionEvents request returns all events  in  the  motion
       history	buffer	that fall between the specified start and stop times,
       inclusive.  If the start time is later than the stop time  or  if  the
       start time is in the future, no events are returned.  If the stop time
       is in the future, it is equivalent to specifying CurrentTime.

       The mode indicates whether the device is reporting absolute positional
       data  (mode=Absolute)  or  relative motion data (mode=Relative).	 Some
       devices allow their mode to be changed via the XSetDeviceMode request.
       These  constants are defined in the file XI.h.  The axis_count returns
       the number of axes or valuators being reported by the device.

       XGetDeviceMotionEvents can generate a BadDevice, or BadMatch error.

STRUCTURES
       The XDeviceTimeCoord structure contains:

       typedef struct {
	    Time time;
	    int *data;
       } XDeviceTimeCoord;

       The time member is set to the time, in milliseconds.  The data  member
       is  a  pointer to an array of integers.	These integers are set to the
       values of each valuator or axis reported by the device.	There is  one
       element	in  the array per axis of motion reported by the device.  The
       value of the array elements depends on the mode of the device.  If the
       mode  is	 Absolute,  the	 values	 are  the raw values generated by the
       device.	These may be scaled by client programs using the maximum val-
       ues  that the device can generate.  The maximum value for each axis of
       the device is reported in the max_val field of the XAxisInfo  returned
       by  the	XListInputDevices request.  If the mode is Relative, the data
       values are the relative values generated by the device.

       You should use XFreeDeviceMotionEvents to free the  data	 returned  by
       this request.

       Errors returned by this request: BadDevice, BadMatch.

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 the speci-
		   fied device is the X keyboard or X pointer device.

       BadMatch	   This error may occur if an XGetDeviceMotionEvents  request
		   is  made  specifying	 a  device  that has no valuators and
		   reports no axes of motion.

SEE ALSO
       Programming with Xlib



						 XGetDeviceMotionEvents(3X11)