XAllowDeviceEvents(3X11) X Version 11(Release 5) 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 AsyncThisDevice,
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 depending 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 continues as usual. If the device
is frozen multiple times by the client on behalf of multiple
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.
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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 completely 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 multiple 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 normally 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, SyncAll 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 processing 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 processing 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.
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XAllowDeviceEvents can generate a BadDevice or BadValue 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 An invalid mode was specified on the request.
SEE ALSO
XGrabDevice(3X11)
Programming With Xlib
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