XGetFeedbackControl
Section: X FUNCTIONS (3X11)
Updated: Release 5
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NAME
XGetFeedbackControl, XChangeFeedbackControl - query and change input device feedbacks
SYNTAX
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
- 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,
LedFeedbackClass, 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.
XFeedbackState 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 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
Index
- NAME
-
- SYNTAX
-
- ARGUMENTS
-
- DESCRIPTION
-
- STRUCTURES
-
- DIAGNOSTICS
-
- SEE ALSO
-
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