XGetFeedbackControl(3X11)XGetFeedbackControl(3X11)NAME
XGetFeedbackControl, XChangeFeedbackControl - query and change input
device feedbacks
SYNOPSIS
XFeedbackState * XGetFeedbackControl(display, device, num_feedbacks)
Display *display;
XDevice *device;
int *num_feedbacks;
int XChangeFeedbackControl(display, device, mask, control)
Display *display;
XDevice *device;
Mask mask;
XFeedbackControl *control;
ARGUMENTS
Specifies the connection to the X server. Specifies the device whose
feedbacks are to be queried or modified. Specifies an address into
which the number of feedbacks supported by the device is to be
returned. Specifies a mask specific to each type of feedback that
describes how the feedback is to be modified. Specifies the address of
an XFeedbackControl structure that contains the new values for the
feedback.
DESCRIPTION
These requests are provided to manipulate those input devices that sup‐
port feedbacks. A BadMatch error will be generated if the requested
device does not support feedbacks. Whether or not a given device sup‐
ports feedbacks can be determined by examining the information returned
by the XOpenDevice request. For those devices that support feedbacks,
XOpenDevice will return an XInputClassInfo structure with the
input_class field equal to the constant FeedbackClass (defined in the
file <XI.h>).
The XGetFeedbackControl request returns a pointer to a list of XFeed‐
backState 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, LedFeed‐
backClass, and BellFeedbackClass. 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. Each feed‐
back 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 XChangeFeedbackControl 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 identified 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>. XFeedback‐
State and XFeedbackControl are generic structures that contain three
fields that are at the beginning 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 keyboard.
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 X pointer.
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;
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;
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
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. This error may occur if an XGetFeed‐
backControl 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 DvAu‐
toRepeatMode for keyboard feedbacks), or if an invalid KeySym is speci‐
fied for a string feedback. Some numeric value falls outside the range
of values accepted by the XChangeFeedbackControl request. Unless a spe‐
cific range is specified for an argument, the full range defined by the
argument's type is accepted. Any argument defined as a set of alterna‐
tives can generate this error.
SEE ALSO
Programming With Xlib
XGetFeedbackControl(3X11)
