XISELECTEVENTS(3)														 XISELECTEVENTS(3)

NAME

       XISelectEvents, XIGetSelectedEvents - select for or get selected XI2 events on the window.

SYNOPSIS

       #include <X11/extensions/XInput2.h>

       Status XISelectEvents( Display *display,
			      Window win,
			      XIEventMask *masks,
			      int num_masks);

       display
	      Specifies the connection to the X server.

       masks
	      Device event mask.

       num_masks
	      Number of masks in masks.

       win
	      Specifies the window.

       XIEventMask *XIGetSelectedEvents( Display *display,
					 Window win,
					 int *num_masks_return);

       display
	      Specifies the connection to the X server.

       num_masks_return
	      Number of masks in the return value.

       win
	      Specifies the window.

DESCRIPTION

	   XI2 events must be selected using XISelectEvents.

	   XISelectEvents sets the event mask for this client on win.
	   Further events are only reported to this client if the event
	   type matches the selected event mask. The masks overrides the
	   previously selected event mask for the given device.

	   If deviceid is a valid device, the event mask is selected only
	   for this device. If deviceid is XIAllDevices or
	   XIAllMasterDevices, the event mask is selected for all devices
	   or all master devices, respectively. The effective event mask
	   is the bit-wise OR of the XIAllDevices, XIAllMasterDevices and
	   the respective device's event mask.

	   typedef struct {
	       int deviceid;
	       int mask_len;
	       unsigned char* mask;
	   } XIEventMask;

	   The mask_len specifies the length of mask in bytes. mask is a
	   binary mask in the form of (1 << event type). deviceid must be
	   either a device or XIAllDevices or XIAllMasterDevices. A client
	   may submit several masks with the same deviceid in one request
	   but only the last mask will be effective.

	   XISelectEvents can generate a BadValue, a BadDevice, and a
	   BadWindow error.

	   XIGetSelectedEvents returns the events selected by this client on the given
	   window. If no events were selected on this window, XIGetSelectedEvents
	   returns NULL and num_masks_return is set to 0. If an internal error occurs,
	   XIGetSelectedEvents returns NULL and num_masks_return is set to -1.
	   Otherwise, XIGetSelectedEvent returns the selected event masks for all
	   devices including the masks for XIAllDevices and XIAllMasterDevices

	   The caller must free the returned data using XFree().

DIAGNOSTICS

	   BadValue
		  A value is outside of the permitted range.

	   BadWindow
		  A value for a Window argument does not name a defined
		  window.

	   BadDevice
		  An invalid device was specified. The device does not
		  exist.

								    03/09/2013							 XISELECTEVENTS(3)