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)