XGetFeedbackControl(3X11) X FUNCTIONS XGetFeedbackControl(3X11)
NAME
XGetFeedbackControl, XChangeFeedbackControl - query and
change input device feedbacks
SYNTAX
XFeedbackState *XGetFeedbackControl(Display *display, XDev-
ice *device, int *num_feedbacks);
int XChangeFeedbackControl(Display *display, XDevice *dev-
ice, Mask mask, XFeedbackControl *control);
ARGUMENTS
display Specifies the connection to the X server.
device Specifies the device whose feedbacks are to
be queried or modified.
num_feedbacks Specifies an address into which the number of
feedbacks supported by the device is to be
returned.
mask Specifies a mask specific to each type of
feedback that describes how the feedback is
to be modified.
control Specifies the address of an XFeedbackControl
structure that contains the new values for
the feedback.
DESCRIPTION
These requests are provided to manipulate those input dev-
ices that support feedbacks. A BadMatch error will be gen-
erated if the requested device does not support feedbacks.
Whether or not a given device supports feedbacks can be
determined by examining the information returned by the
XOpenDevice request. For those devices that support feed-
backs, XOpenDevice will return an XInputClassInfo structure
with the input_class field equal to the constant Feed-
backClass (defined in the file XI.h).
The XGetFeedbackControl request returns a pointer to a list
of XFeedbackState structures. Each item in this list
describes one of the feedbacks supported by the device. The
items are variable length, so each contains its length to
allow traversal to the next item in the list.
The feedback classes that are currently defined are:
KbdFeedbackClass, PtrFeedbackClass, StringFeedbackClass,
IntegerFeedbackClass, LedFeedbackClass, and BellFeed-
backClass. These constants are defined in the file XI.h.
An input device may support zero or more classes of feed-
back, and may support multiple feedbacks of the same class.
XFree86 Version 4.5.0 1
XGetFeedbackControl(3X11) X FUNCTIONS XGetFeedbackControl(3X11)
Each feedback contains a class identifier and an id that is
unique within that class for that input device. The id is
used to identify the feedback when making an XChangeFeed-
backControl request.
XGetFeedbackControl can generate a BadDevice or BadMatch
error.
The XChangeFeedbackControl request modifies the values of
one feedback on the specified device. The feedback is iden-
tified by the id field of the XFeedbackControl structure
that is passed with the request. The fields of the feedback
that are to be modified are identified by the bits of the
mask that is passed with the request.
XChangeFeedbackControl can generate a BadDevice, BadMatch,
or BadValue error.
STRUCTURES
Each class of feedback is described by a structure specific
to that class. These structures are defined in the file
XInput.h. XFeedbackState and XFeedbackControl are generic
structures that contain three fields that are at the begin-
ning of each class of feedback:
typedef struct {
XID class;
int length;
XID id;
} XFeedbackState, XFeedbackControl;
The XKbdFeedbackState structure defines the attributes that
are returned for feedbacks equivalent to those on the X key-
board.
typedef struct {
XID class;
int length;
XID id;
int click;
int percent;
int pitch;
int duration;
int led_mask;
int global_auto_repeat;
char auto_repeats[32];
} XKbdFeedbackState;
The XPtrFeedbackState structure defines the attributes that
are returned for feedbacks equivalent to those on the the X
pointer.
XFree86 Version 4.5.0 2
XGetFeedbackControl(3X11) X FUNCTIONS XGetFeedbackControl(3X11)
typedef struct {
XID class;
int length;
XID id;
int accelNum;
int accelDenom;
int threshold;
} XPtrFeedbackState;
The XIntegerFeedbackState structure defines attributes that
are returned for integer feedbacks.
typedef struct {
XID class;
int length;
XID id;
int resolution;
int minVal;
int maxVal;
} XIntegerFeedbackState;
The XStringFeedbackState structure defines the attributes
that are returned for string feedbacks.
typedef struct {
XID class;
int length;
XID id;
int max_symbols;
int num_syms_supported;
KeySym *syms_supported;
} XStringFeedbackState;
The XBellFeedbackState structure defines the attributes that
are returned for bell feedbacks.
typedef struct {
XID class;
int length;
XID id;
int percent;
int pitch;
int duration;
} XBellFeedbackState;
The XLedFeedbackState structure defines the attributes that
are returned for LED feedbacks.
typedef struct {
XID class;
int length;
XID id;
XFree86 Version 4.5.0 3
XGetFeedbackControl(3X11) X FUNCTIONS XGetFeedbackControl(3X11)
int led_values;
} XLedFeedbackState;
The XPrtFeedbackControl structure defines the attributes
that can be controlled for pointer feedbacks.
typedef struct {
XID class;
int length;
XID id;
int accelNum;
int accelDenom;
int threshold;
} XPtrFeedbackControl;
The XKbdFeedbackControl structure defines the attributes
that can be controlled for keyboard feedbacks.
typedef struct {
XID class;
int length;
XID id;
int click;
int percent;
int pitch;
int duration;
int led_mask;
int led_value;
int key;
int auto_repeat_mode;
} XKbdFeedbackControl;
The XStringFeedbackControl structure defines the attributes
that can be controlled for string feedbacks.
typedef struct {
XID class;
int length;
XID id;
int num_keysyms;
KeySym *syms_to_display;
} XStringFeedbackControl;
The XIntegerFeedbackControl structure defines the attributes
that can be controlled for integer feedbacks.
typedef struct {
XID class;
int length;
XID id;
int int_to_display;
} XIntegerFeedbackControl;
XFree86 Version 4.5.0 4
XGetFeedbackControl(3X11) X FUNCTIONS XGetFeedbackControl(3X11)
The XBellFeedbackControl structure defines the attributes
that can be controlled for bell feedbacks.
typedef struct {
XID class;
int length;
XID id;
int percent;
int pitch;
int duration;
} XBellFeedbackControl;
The XLedFeedbackControl structure defines the attributes
that can be controlled for LED feedbacks.
typedef struct {
XID class;
int length;
XID id;
int led_mask;
int led_values;
} XLedFeedbackControl;
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.
BadMatch This error may occur if an XGetFeedbackControl
request was made specifying a device that has no
feedbacks, or an XChangeFeedbackControl request
was made with an XFeedbackControl structure that
contains an invalid feedback type. It may also
occur if an invalid combination of mask bits is
specified (DvKey but no DvAutoRepeatMode for
keyboard feedbacks), or if an invalid KeySym is
specified for a string feedback.
BadValue Some numeric value falls outside the range of
values accepted by the XChangeFeedbackControl
request. Unless a specific range is specified
for an argument, the full range defined by the
argument's type is accepted. Any argument
defined as a set of alternatives can generate
this error.
SEE ALSO
Programming With Xlib
XFree86 Version 4.5.0 5