'\" t
.\"     Title: xgrabdevice
.\"    Author: [FIXME: author] [see http://www.docbook.org/tdg5/en/html/author]
.\" Generator: DocBook XSL Stylesheets vsnapshot <http://docbook.sf.net/>
.\"      Date: 05/04/2023
.\"    Manual: \ \&
.\"    Source: \ \&
.\"  Language: English
.\"
.TH "XGRABDEVICE" "3" "05/04/2023" "\ \&" "\ \&"
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.SH "NAME"
XGrabDevice, XUngrabDevice \- grab/release the specified extension device
.SH "SYNOPSIS"
.sp
.nf
#include <X11/extensions/XInput\&.h>
.fi
.sp
.nf
int XGrabDevice( Display *display,
                 XDevice* device,
                 Window grab_window,
                 Bool owner_events,
                 int event_count,
                 XEventClass *event_list,
                 int this_device_mode,
                 int other_devices_mode,
                 Time time);
.fi
.sp
.nf
int XUngrabDevice( Display *display,
                   XDevice *device,
                   Time time);
.fi
.sp
.nf
display
       Specifies the connection to the X server\&.
.fi
.sp
.nf
device
       Specifies the device to be grabbed or released\&.
.fi
.sp
.nf
grab_window
       Specifies the id of a window to be associated with the
       device\&.
.fi
.sp
.nf
owner_events
       Specifies a Boolean value that indicates whether
       the events from the device are to be reported as usual or
       reported with respect to the grab window if selected by
       the event list\&.
.fi
.sp
.nf
event_count
       Specifies the number of elements in the event_list
       array\&.
.fi
.sp
.nf
event_list
       Specifies a pointer to a list of event classes that
       indicates which events the client wishes to receive\&.
       These event classes must have been obtained specifying
       the device being grabbed\&.
.fi
.sp
.nf
this_device_mode
       Specifies further processing of events from this
       device\&. You can pass GrabModeSync or GrabModeAsync\&.
.fi
.sp
.nf
other_devices_mode
       Specifies further processing of events from other
       devices\&. You can pass GrabModeSync or GrabModeAsync\&.
.fi
.sp
.nf
time
       Specifies the time\&. You can pass either a timestamp or
       CurrentTime\&.
.fi
.SH "DESCRIPTION"
.sp
.if n \{\
.RS 4
.\}
.nf
The XGrabDevice request actively grabs control of the device
and generates DeviceFocusIn and DeviceFocusOut events\&. Further
device events are reported only to the grabbing
client\&. XGrabDevice overrides any active device grab by this
client\&. event_list is a pointer to a list of event classes\&.
This list indicates which events the client wishes to receive
while the grab is active\&. If owner_events is False, all
generated device events are reported with respect to
grab_window if selected\&. If owner_events is True and if a
generated device event would normally be reported to this
client, it is reported normally; otherwise, the event is
reported with respect to the grab_window, and is only reported
if specified in the event_list\&.
.fi
.if n \{\
.RE
.\}
.sp
.if n \{\
.RS 4
.\}
.nf
If the this_device_mode argument is GrabModeAsync, device event
processing continues as usual\&. If the device is currently
frozen by this client, then processing of device events is
resumed\&. If the this_device_mode argument is GrabModeSync, the
state of the device (as seen by client applications) appears to
freeze, and the X server generates no further device events
until the grabbing client issues a releasing XAllowDeviceEvents
call or until the device grab is released\&. Actual device
changes are not lost while the device is frozen; they are
simply queued in the server for later processing\&.
.fi
.if n \{\
.RE
.\}
.sp
.if n \{\
.RS 4
.\}
.nf
If other_devices_mode is GrabModeAsync, processing of events
from other devices is unaffected by activation of the grab\&. If
other_devices_mode is GrabModeSync, the state of all devices
except the grabbed device (as seen by client applications)
appears to freeze, and the X server generates no further events
from those devices until the grabbing client issues a releasing
XAllowDeviceEvents call or until the device grab is released\&.
Actual events are not lost while the devices are frozen; they
are simply queued in the server for later processing\&.
.fi
.if n \{\
.RE
.\}
.sp
.if n \{\
.RS 4
.\}
.nf
If the device is actively grabbed by some other client,
XGrabDevice fails and returns AlreadyGrabbed\&. If grab_window is
not viewable, it fails and returns GrabNotViewable\&. If the
device is frozen by an active grab of another client, it fails
and returns GrabFrozen\&. If the specified time is earlier than
the last\-device\-grab time or later than the current X server
time, it fails and returns GrabInvalidTime\&. Otherwise, the
last\-device\-grab time is set to the specified time
(CurrentTime is replaced by the current X server time)\&.
.fi
.if n \{\
.RE
.\}
.sp
.if n \{\
.RS 4
.\}
.nf
If a grabbed device is closed by a client while an active grab
by that client is in effect, the active grab is released\&. If
the device is frozen only by an active grab of the requesting
client, it is thawed\&.
.fi
.if n \{\
.RE
.\}
.sp
.if n \{\
.RS 4
.\}
.nf
XGrabDevice can generate BadClass, BadDevice, BadValue, and
BadWindow errors\&.
.fi
.if n \{\
.RE
.\}
.sp
.if n \{\
.RS 4
.\}
.nf
The XUngrabDevice request releases the device and any queued
events if this client has it actively grabbed from either
XGrabDevice or XGrabDeviceKey\&. If other devices are frozen by
the grab, XUngrabDevice thaws them\&. XUngrabDevice does not
release the device and any queued events if the specified time
is earlier than the last\-device\-grab time or is later than the
current X server time\&. It also generates DeviceFocusIn and
DeviceFocusOut events\&. The X server automatically performs an
UngrabDevice request if the event window for an active device
grab becomes not viewable\&.
.fi
.if n \{\
.RE
.\}
.sp
.if n \{\
.RS 4
.\}
.nf
XUngrabDevice can generate a BadDevice error\&.
.fi
.if n \{\
.RE
.\}
.SH "DIAGNOSTICS"
.sp
.if n \{\
.RS 4
.\}
.nf
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 the
       specified device is the X keyboard or X pointer device\&.
.fi
.if n \{\
.RE
.\}
.sp
.if n \{\
.RS 4
.\}
.nf
BadValue
       Some numeric value falls outside the range of values
       accepted by the request\&. Unless a specific range is
       specified for an argument, the full range defined by the
       argument\*(Aqs type is accepted\&. Any argument defined as a
       set of alternatives can generate this error\&.
.fi
.if n \{\
.RE
.\}
.sp
.if n \{\
.RS 4
.\}
.nf
BadWindow
       A value for a Window argument does not name a defined
       Window\&.
.fi
.if n \{\
.RE
.\}
.SH "SEE ALSO"
.sp
.if n \{\
.RS 4
.\}
.nf
XAllowDeviceEvents(3), XGrabDeviceButton(3), XGrabDeviceKey(3)
.fi
.if n \{\
.RE
.\}