XGrabDevice(3X11) X Version 11 (Release 6.6) XGrabDevice(3X11)
NAME
XGrabDevice, XUngrabDevice - grab/release the specified
extension device
SYNTAX
int XGrabDevice(display, device, grab_window, owner_events, event_count, event_list,
this_device_mode, other_devices_mode, time)
Display *display;
XDevice *device;
Window grab_window;
Bool owner_events;
int event_count;
XEventClass *event_list;
int this_device_mode, other_devices_mode;
Time time;
XUngrabDevice(display, device, time)
Display *display;
XDevice *device;
Time time;
ARGUMENTS
display Specifies the connection to the X server.
device Specifies the device to be grabbed or released.
grab_window Specifies the id of a window to be associated
with the device.
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.
event_count Specifies the number of elements in the
event_list array.
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.
this_device_mode
Specifies further processing of events from this
device. You can pass GrabModeSync or
GrabModeAsync.
other_devices_mode
Specifies further processing of events from
other devices. You can pass GrabModeSync or
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XGrabDevice(3X11) X Version 11 (Release 6.6) XGrabDevice(3X11)
GrabModeAsync.
time Specifies the time. You can pass either a
timestamp or CurrentTime.
DESCRIPTION
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.
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.
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.
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
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set to the specified time ( CurrentTime is replaced by the
current X server time).
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.
XGrabDevice can generate BadClass, BadDevice, BadValue, and
BadWindow errors.
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.
XUngrabDevice can generate a BadDevice error.
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 the specified device is the X
keyboard or X pointer device.
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's type is
accepted. Any argument defined as a set of
alternatives can generate this error.
BadWindow A value for a Window argument does not name a
defined Window.
SEE ALSO
XAllowDeviceEvents(3X), XGrabDeviceButton(3X),
XGrabDeviceKey(3X),
Programming With Xlib
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