XGETDEVICEPROPERTY

NAME
SYNOPSIS
DESCRIPTION
DIAGNOSIS
SEE ALSO

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NAME

XGetDeviceProperty, XChangeDeviceProperty, XDeleteDeviceProperty − Get, change or delete a device´s property.

SYNOPSIS

#include <X11/extensions/XInput.h>

int XGetDeviceProperty( Display *display,
XDevice *device,
Atom property,
long offset,
long length,
Bool delete,
Atom req_type,
Atom *actual_type_return,
int *actual_format_return,
unsigned long *nitems_return,
unsigned long *bytes_after_return,
unsigned char **prop_return)

void XChangeDeviceProperty( Display *display,
XDevice *device,
Atom property,
Atom type,
int format,
int mode,
const char *data,
int nelements)

void XDeleteDeviceProperty( Display *display,
XDevice *device,
Atom property)

actual_type_return
Returns an atom identifier that defines the actual type
of the property.

actual_format_return
Returns the actual format of the property.

bytes_after_return
Returns the number of bytes remaining to be read in the
property if a partial read was performed.

data
Specifies the property data.

delete
Specifies a Boolean value that determines whether the
property is deleted.

display
Specifies the connection to the X server.

device
The device to grab.

format
Specifies whether the data should be viewed as a list of
8−bit, 16−bit, or 32−bit quantities. Possible values are
8, 16, and 32. This information allows the X server to
correctly perform byte−swap operations as necessary. If
the format is 16−bit or 32−bit, you must explicitly cast
the data pointer to an (unsigned char*) in the call to
XChangeDeviceProperty.

length
Specifies the length in 32−bit multiplies of the data to
be retrieved.

mode
Specifies the mode of operation. You can pass
PropModeReplace, PropModePrepend, or PropModeAppend.

nelements
Specifies the number of elements in data.

nitems_return
Returns the actual number of 8−bit, 16−bit, or 32−bit
items stored in the prop_return array.

num_values
Specifies the number of elements in the values list.

offset
Specifies the offset in the specified property (in
32−bit quantities) where the data is to be retrieved.

property
Specifies the property to modify or query.

prop_return
Returns the data in the specified format. If the
returned format is 8, the returned data is represented
as a char array. If the returned format is 16, the
returned data is represented as an array of short int
type and should be cast to that type to obtain the
elements. If the returned format is 32, the property
data will be stored as an array of longs (which in a
64−bit application will be 64−bit values that are padded
in the upper 4 bytes).

req_type
Specifies the atom identifier associated with the
property type or AnyPropertyType.

DESCRIPTION

The XGetDeviceProperty function returns the actual type of the property; the actual format of the property; the number of 8−bit, 16−bit, or 32−bit items transferred; the number of bytes remaining to be read in the property; and a pointer to the data actually returned. For a detailed description of this function, see the man page to XGetWindowProperty.

The XChangeDeviceProperty function alters the property for the specified device and causes the server to generate a XPropertyNotifyEvent event on that device. For a detailed description of this function, see the man page to XChangeProperty.

The XDeleteDeviceProperty function deletes the specified device property. Note that a client cannot delete a property created by a driver or the server. Attempting to do so will result in a BadAtom error.

XGetDeviceProperty can generate a BadAtom, BadDevice error.

XChangeDeviceProperty can generate a BadDevice, a BadMatch, a BadAtom, and a BadValue error.

XDeleteDeviceProperty can generate a BadDevice, and a BadAtom error.

DIAGNOSIS

BadAtom
A value does not describe a valid named identifier or
the client attempted to remove a driver−allocated
property.

BadDevice
An invalid device was specified. The device does not
exist.

SEE ALSO

XListDeviceProperties(3)

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