XAllowDeviceEvents(3X11)
NAME
XAllowDeviceEvents - release queued events
SYNTAX
XAllowDeviceEvents(display, device, event_mode, time)
Display *display;
XDevice *device;
int event_mode;
Time time;
ARGUMENTS
display Specifies the connection to the X server.
device Specifies the device from which events are to
be allowed.
event_mode Specifies the event mode. You can pass Async-
ThisDevice, SyncThisDevice, ReplayThisDevice,
AsyncOtherDevices, SyncAll, or AsyncAll.
time Specifies the time. You can pass either a
timestamp or CurrentTime.
DESCRIPTION
The XAllowDeviceEvents function releases some queued
events if the client has caused a device to freeze. It
has no effect if the specified time is earlier than the
last-grab time of the most recent active grab for the
client and device, or if the specified time is later than
the current X server time.
The following describes the processing that occurs depend-
ing on what constant you pass to the event_mode argument.
AsyncThisDevice
If the specified device is frozen by the
client, event processing for that device con-
tinues as usual. If the device is frozen mul-
tiple times by the client on behalf of multi-
ple separate grabs, AsyncThisDevice thaws for
all. AsyncThisDevice has no effect if the
specified device is not frozen by the client,
but the device need not be grabbed by the
client.
SyncThisDevice
If the specified device is frozen and actively
grabbed by the client, event processing for
that device continues normally until the next
key or button event is reported to the client.
At this time, the specified device again
appears to freeze. However, if the reported
event causes the grab to be released, the
specified device does not freeze.
SyncThisDevice has no effect if the specified
device is not frozen by the client or is not
grabbed by the client.
ReplayThisDevice
If the specified device is actively grabbed by
the client and is frozen as the result of an
event having been sent to the client (either
from the activation of a GrabDeviceButton or
from a previous AllowDeviceEvents with mode
SyncThisDevice, but not from a GrabDevice),
the grab is released and that event is com-
pletely reprocessed. This time, however, the
request ignores any passive grabs at or above
(toward the root) that the grab-window of the
grab just released. The request has no effect
if the specified device is not grabbed by the
client or if it is not frozen as the result of
an event.
AsyncOtherDevices
If the remaining devices are frozen by the
client, event processing for them continues as
usual. If the other devices are frozen multi-
ple times by the client on behalf of multiple
grabs, AsyncOtherDevices "thaws" for all.
AsyncOtherDevices has no effect if the devices
are not frozen by the client.
SyncAll If all devices are frozen by the client, event
processing (for all devices) continues nor-
mally until the next button or key event is
reported to the client for a grabbed device,
at which time all devices again appear to
freeze. However, if the reported event causes
the grab to be released, then the devices do
not freeze. If any device is still grabbed,
then a subsequent event for it will still
cause all devices to freeze. SyncAll has no
effect unless all devices are frozen by the
client. If any device is frozen twice by the
client on behalf of two separate grabs, Syn-
cAll thaws for both. A subsequent freeze for
SyncAll will only freeze each device once.
AsyncAll If all devices are frozen by the client, event
processing for all devices continues normally.
If any device is frozen multiple times by the
client on behalf of multiple separate grabs,
AsyncAll thaws for all. AsyncAll has no
effect unless all devices are frozen by the
client.
AsyncThisDevice, SyncThisDevice, and ReplayThisDevice have
no effect on the processing of events from the remaining
devices. AsyncOtherDevices has no effect on the process-
ing of events from the specified device. When the
event_mode is SyncAll or AsyncAll, the device parameter is
ignored.
It is possible for several grabs of different devices by
the same or different clients to be active simultaneously.
If a device is frozen on behalf of any grab, no event pro-
cessing is performed for the device. It is possible for a
single device to be frozen because of several grabs. In
this case, the freeze must be released on behalf of each
grab before events can again be processed.
XAllowDeviceEvents can generate a BadDevice or BadValue
error.
DIAGNOSTICS
BadDevice An invalid device was specified. The speci-
fied 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 An invalid mode was specified on the request.
SEE ALSO
XGrabDevice(3X11)
Programming With Xlib