XALLOWDEVICEEVENTS(3) XALLOWDEVICEEVENTS(3)

NAME

XAllowDeviceEvents - release queued events

SYNOPSIS

#include <X11/extensions/XInput.h>

int XAllowDeviceEvents( Display *display,
XDevice *device,
int event_mode,
Time time);
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.

+o 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.

+o 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.

+o 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.

+o 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.

+o 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.

+o 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.

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(3)

06/19/2019 XALLOWDEVICEEVENTS(3)