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XAllowDeviceEvents - release queued events
- 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.
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.
- 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.
XGrabDevice(3X11)
Programming With Xlib
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