int XChangeFeedbackControl(display, device, mask, control) 
      Display *display;
 
      XDevice *device; 
 
      Mask mask; 
 
      XFeedbackControl *control; 
 
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.
 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;