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;