int XAllowDeviceEvents(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.
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.
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.
