Skip site navigation (1)Skip section navigation (2)

FreeBSD Manual Pages

  
 
  

home | help
XLISTINPUTDEVICES(3)					  XLISTINPUTDEVICES(3)

NAME
       XListInputDevices, XFreeDeviceList - list available input devices

SYNOPSIS
       #include	<X11/extensions/XInput.h>

       XDeviceInfo *XListInputDevices( Display *display,
				       int *ndevices_return);

       int XFreeDeviceList( XDeviceInfo	*list);

       display
	      Specifies	the connection to the X	server.

       ndevices_return
	      Specifies	a pointer to a variable	where the number of
	      available	devices	canbe returned.

       list
	      Specifies	the list of devices to free. The
	      XFreeDeviceList functionfrees the	list of	available
	      extension	input devices.

DESCRIPTION
	   The XListInputDevices request lists the available input
	   devices. This list includes the core	keyboard and any physical
	   input device	currently accessible through the X server, and any
	   input devices that are not currently	accessible through the X
	   server but could be accessed	if requested.

	   A master pointer is a virtual pointer device	that does not
	   represent a physical	device.	It is visually represented through
	   a cursor. A master keyboard is a virtual keyboard device that
	   does	not represent a	physical device. It is virtually
	   representd through a	keyboard focus.	A master pointer and a
	   master keyboard are always paired (i.e. if shift is pressed on
	   the master keyboard,	a pointer click	would be a shift-click).
	   Multiple master pointer/keyboard pairs can exist.

	   X servers supporting	the X Input Extension version 2,
	   XListInputDevices only returns the first master pointer, the
	   first master	keyboard and all slave devices.	Additional master
	   devices are not listed.

	   Physical devices (so-called slave devices) are attached to
	   either a master pointer or a	master keyboard, depending on
	   their capabilities. If a slave device generates an event, the
	   event is also generated by the respective master device.
	   Multiple slave devices can be attached to a single master
	   device.

	   Some	server implementations may make	all physical input devices
	   available at	the time the server is initialized. Others may
	   wait	until requested	by a client to access an input device. In
	   the latter case, it is possible that	an input device	will be
	   listed as available at one time but not at another.

	   For each input device available to the server, the
	   XListInputDevices request returns an	XDeviceInfo structure.
	   That	structure contains a pointer to	a list of structures, each
	   of which contains information about one class of input
	   supported by	the device. The	XDeviceInfo structure is defined
	   as follows:
			typedef	struct _XDeviceInfo {
			XID	id;
			Atom	type;
			char	*name;
			int	    num_classes;
			int	    use;
			XAnyClassPtr inputclassinfo;
			} XDeviceInfo;

	   The id is a number in the range 0-128 that uniquely identifies
	   the device. It is assigned to the device when it is initialized
	   by the server.

	   The type field is of	type Atom and indicates	the nature of the
	   device. The type will correspond to one of the following strings
	   (defined in the header file XI.h):

	   XI_MOUSE XI_TABLET XI_KEYBOARD XI_TOUCHSCREEN XI_TOUCHPAD
	   XI_BUTTONBOX	XI_BARCODE XI_TRACKBALL	XI_QUADRATURE XI_ID_MODULE
	   XI_ONE_KNOB XI_NINE_KNOB XI_KNOB_BOX	XI_SPACEBALL XI_DATAGLOVE
	   XI_EYETRACKER XI_CURSORKEYS XI_FOOTMOUSE XI_JOYSTICK

	   These strings may be	used in	an XInternAtom request to return
	   an atom that	can be compared	with the type field of the
	   XDeviceInfo structure.

	   The name field contains a pointer to	a null-terminated string
	   that	serves as identifier of	the device. This identifier may	be
	   user-configured or automatically assigned by	the server.

	   The num_classes field is a number in	the range 0-255	that
	   specifies the number	of input classes supported by the device
	   for which information is returned by	ListInputDevices. Some
	   input classes, such as class	Focus and class	Proximity do not
	   have	any information	to be returned by ListInputDevices.

	   All devices provide an AttachClass. This class specifies the
	   master device a given slave device is attached to. For master
	   devices, the	class specifies	the respective paired master
	   device.

	   The use field specifies how the device is currently being used.
	   If the value	is IsXKeyboard,	the device is a	master keyboard.
	   If the value	is IsXPointer, the device is a master pointer. If
	   the value is	IsXExtensionPointer, the device	is a slave
	   pointer. If the value is IsXExtensionKeyboard, the device is	a
	   slave keyboard. If the value	is IsXExtensionDevice, the device
	   is available	for use	as an extension	device.

	   The inputclassinfo field contains a pointer to the first
	   input-class specific	data. The first	two fields are common to
	   all classes.

	   The class field is a	number in the range 0-255. It uniquely
	   identifies the class	of input for which information is
	   returned. Currently defined classes are KeyClass, ButtonClass,
	   and ValuatorClass.

	   The length field is a number	in the range 0-	255. It	specifies
	   the number of bytes of data that are	contained in this input
	   class. The length includes the class	and length fields.

	   The XKeyInfo	structure describes the	characteristics	of the
	   keys	on the device. It is defined as	follows:

	   typedef struct _XKeyInfo {
	   XID class;
	   int length;
	   unsigned short min_keycode;
	   unsigned short max_keycode;
	   unsigned short num_keys;
	   } XKeyInfo;

	   min_keycode is of type KEYCODE. It specifies	the minimum
	   keycode that	the device will	report.	The minimum keycode will
	   not be smaller than 8.

	   max_keycode is of type KEYCODE. It specifies	the maximum
	   keycode that	the device will	report.	The maximum keycode will
	   not be larger than 255.

	   num_keys specifies the number of keys that the device has.

	   The XButtonInfo structure defines the characteristics of the
	   buttons on the device. It is	defined	as follows:

	   typedef struct _XButtonInfo {
	   XID class;
	   int length;
	   short num_buttons;
	   } XButtonInfo;

	   num_buttons specifies the number of buttons that the	device
	   has.

	   The XValuatorInfo structure defines the characteristics of the
	   valuators on	the device. It is defined as follows:

	   typedef struct  _XValuatorInfo {
	   XID class;
	   int length;
	   unsigned char num_axes;
	   unsigned char mode;
	   unsigned long motion_buffer;
	   XAxisInfoPtr	axes;
	   } XValuatorInfo;

	   num_axes contains the number	of axes	the device supports.

	   mode	is a constant that has one of the following values:
	   Absolute or Relative. Some devices allow the	mode to	be changed
	   dynamically via the SetDeviceMode request.

	   motion_buffer_size is a cardinal number that	specifies the
	   number of elements that can be contained in the motion history
	   buffer for the device.

	   The axes field contains a pointer to	an XAxisInfo structure.

	   The XAxisInfo structure is defined as follows:

	   typedef struct _XAxisInfo {
	   int resolution;
	   int min_value;
	   int max_value;
	   } XAxisInfo;

	   The resolution contains a number in counts/meter.

	   The min_val field contains a	number that specifies the minimum
	   value the device reports for	this axis. For devices whose mode
	   is Relative,	the min_val field will contain 0.

	   The max_val field contains a	number that specifies the maximum
	   value the device reports for	this axis. For devices whose mode
	   is Relative,	the max_val field will contain 0.

	   The XAttachInfo structure is	defined	as follows:
			typedef	struct _XAttachInfo {
			int	attached;
			} XAttachInfo;

	   If the device is a slave device, attached specifies the device
	   ID of the master device this	device is attached to. If the
	   device is not attached to a master device, attached is
	   Floating. If	the device is a	master device, attached	specifies
	   the device ID of the	master device this device is paired with.

RETURN VALUE
	   XListInputDevices returns a pointer to an array of XDeviceInfo
	   structs and sets ndevices_return to the number of elements in
	   that	array. To free the XDeviceInfo array created by
	   XListInputDevices, use XFreeDeviceList.

	   On error, XListInputDevices returns NULL and	ndevices_return	is
	   left	unmodified.

				  10/13/2016		  XLISTINPUTDEVICES(3)

NAME | SYNOPSIS | DESCRIPTION | RETURN VALUE

Want to link to this manual page? Use this URL:
<https://www.freebsd.org/cgi/man.cgi?query=XListInputDevices&sektion=3&manpath=FreeBSD+12.0-RELEASE+and+Ports>

home | help