XGETDEVICECONTROL(3) libXi XGETDEVICECONTROL(3)NAME
XGetDeviceControl, XChangeDeviceControl - query and change input device
controls
SYNTAX
#include <X11/extensions/XInput.h>
XDeviceControl *XGetDeviceControl(Display *display, XDevice*device,
int *controlType);
int XChangeDeviceControl(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
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..SH 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.
SEE ALSO
03/04/2009 XGETDEVICECONTROL(3)
