XGrabDevice(3X11) SDK X11 R4.11MU05 XGrabDevice(3X11)
NAME
XGrabDevice, XUngrabDevice - grab/release the specified extension
device
SYNTAX
int XGrabDevice(display, device, grabwindow, ownerevents, eventcount, eventlist,
thisdevicemode, otherdevicesmode, time)
Display *display;
XDevice *device;
Window grabwindow;
Bool ownerevents;
int eventcount;
XEventClass *eventlist;
int thisdevicemode, otherdevicesmode;
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.
grabwindow Specifies the id of a window to be associated with the
device.
ownerevents
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.
eventcount Specifies the number of elements in the event_list array.
eventlist 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.
thisdevicemode
Specifies further processing of events from this device.
You can pass GrabModeSync or GrabModeAsync.
otherdevicesmode
Specifies further processing of events from other
devices. You can pass GrabModeSync or 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 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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