XGetDeviceControl(3X11) X FUNCTIONS XGetDeviceControl(3X11)
NAME
XGetDeviceControl, XChangeDeviceControl - query and change
input device controls
SYNTAX
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 interro-
gated 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 dev-
ices that support device control. A BadMatch error will be
generated if the requested device does not support any dev-
ice 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 XDevi-
ceControl 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
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XGetDeviceControl(3X11) X FUNCTIONS XGetDeviceControl(3X11)
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 attri-
butes 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 con-
tains an invalid Device type. It may also occur
if an invalid combination of mask bits is speci-
fied (DvKey but no DvAutoRepeatMode for keyboard
Devices), or if an invalid KeySym is specified
for a string Device.
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XGetDeviceControl(3X11) X FUNCTIONS XGetDeviceControl(3X11)
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
XFree86 Version 4.5.0 3