XGETDEVICECONTROL(3)

NAME
XGetDeviceControl, XChangeDeviceControl - query and change input device controls

SYNOPSIS

#include <X11/extensions/XInput.h>

XDeviceControl *XGetDeviceControl( Display *display,
                                   XDevice *device,
                                   int *controlType);

int XChangeDeviceControl( Display *display,
                          XDevice *device,
                          int controlType,
                          XDeviceControl *control);

display
       Specifies the connection to the X server.

device
       Specifies the device whose control is to be interrogated
       or modified.

controlType
       Specifies the type of control to be interrogated or
       changed.

control
       Specifies the address of an XDeviceControl structure
       that contains the new values for the Device.

DESCRIPTION

    These requests are provided to manipulate those input devices
    that support device control. A BadMatch error will be generated
    if the requested device does not support any device controls.

    Valid device control types that can be used with these requests
    include the following:

    DEVICE_RESOLUTION: Queries or changes the resolution of
    valuators on input devices.

    The XGetDeviceControl request returns a pointer to an
    XDeviceControl structure.

    XGetDeviceControl can generate a BadDevice or BadMatch error.

    The XChangeDeviceControl request modifies the values of one
    control on the specified device. The control is identified by
    the id field of the XDeviceControl structure that is passed
    with the request.

    XChangeDeviceControl can generate a BadDevice, BadMatch, or
    BadValue error.

STRUCTURES

    Each control is described by a structure specific to that control.
    These structures are defined in the file XInput.h.

    XDeviceControl is a generic structure that contains two fields
    that are at the beginning of each class of control:

    typedef struct {
        XID class;
        int length;
    } XDeviceControl;

    The XDeviceResolutionState structure defines the information
    that is returned for device resolution for devices with
    valuators.

    typedef struct {
        XID control;
        int length;
        int num_valuators;
        int* resolutions;
        int* min_resolutions;
        int* max_resolutions;
    } XDeviceResolutionState;

    The XDeviceResolutionControl structure defines the attributes
    that can be controlled for keyboard Devices.

    typedef struct {
        XID control;
        int length;
        int first_valuator;
        int num_valuators;
        int* resolutions;
    } XDeviceResolutionControl;

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 XGetDeviceControl request was
           made specifying a device that has no controls or an
           XChangeDeviceControl request was made with an
           XDeviceControl structure that contains an invalid Device
           type. It may also occur if an invalid combination of
           mask bits is specified ( DvKey but no DvAutoRepeatMode
           for keyboard Devices), or if an invalid KeySym is
           specified for a string Device.

    BadValue
           Some numeric value falls outside the range of values
           accepted by the XChangeDeviceControl 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.