XChDCtl(1) X Version 11 XChDCtl(1)XGetDeviceControl(3X11) X FUNCTIONS XGetDeviceControl(3X11)NAME
XGetDeviceControl, XChangeDeviceControl - query and change input device
controls
SYNTAX
XDeviceControl * XGetDeviceControl(display, device, control)
Display *display;
XDevice *device;
int *controlType;
int XChangeDeviceControl(display, device, controlType, control)
Display *display;
XDevice *device;
int controlType;
XDeviceControl *control;
ARGUMENTS
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 sup‐
port 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 XOpen‐
InputDevice. This error may also occur if some other
client has caused the specified device to become the X key‐
board 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 XDeviceCon‐
trol 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.
SEE ALSO
Programming With Xlib
X Version 11 Release 6 XGetDeviceControl(3X11)
