XGetFeedbackControl(3X11) X FUNCTIONS XGetFeedbackControl(3X11)
NAME
XGetFeedbackControl, XChangeFeedbackControl - query and change input device feedbacks
SYNTAX
XFeedbackState *XGetFeedbackControl(Display *display, XDevice *device, int *num_feedbacks);
int XChangeFeedbackControl(Display *display, XDevice *device, 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 devices that support feedbacks. A BadMatch error will be generated 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 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 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, Led-
FeedbackClass, and BellFeedbackClass. These constants are defined in the file XI.h. An input device may support zero or more classes of
feedback, and may support multiple feedbacks of the same class. 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 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 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
BadDevice An invalid device was specified. The specified device does not exist or has not been opened by this client via XOpenInputDe-
vice. 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 XChangeFeed-
backControl 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 4.7.0 XGetFeedbackControl(3X11)