xref: /xsrc/external/mit/libXi/dist/man/XIGrabDevice.txt

XIGRABDEVICE(libmansuffix)
==========================

NAME
----

   XIGrabDevice, XIUngrabDevice - grab or ungrab the device.

SYNOPSIS
--------

   #include <X11/extensions/XInput2.h>

   Status XIGrabDevice( Display *display,
                        int deviceid,
                        Window grab_window,
                        Time time,
                        Cursor cursor,
                        int grab_mode,
                        int paired_device_mode,
                        Bool owner_events,
                        XIEventMask *mask);
   
   Status XIUngrabDevice( Display *display,
                          int deviceid,
                          Time time);

   cursor
          Specifies the cursor image to display for the duration
          of the grab.

   display
          Specifies the connection to the X server.

   deviceid
          Specifies the device that should be grabbed or
          ungrabbed.

   grab_mode, paired_device_mode
          The grab mode for this device and (if applicable) the
          paired device.

   grab_window
          The grab window.

   mask
          Event mask.

   owner_events
          True if events are to be reported normally.

   time
          A valid timestamp or CurrentTime.

DESCRIPTION
-----------

   XIGrabDevice actively grabs control of the device. Further
   device events are reported only to the grabbing client.
   XIGrabDevice overrides any active device grab by this client.

   If the device is an attached slave device, the device is
   automatically detached from the master device and reattached to
   the same master device when client ungrabs the device. If the
   master device is removed while the device is floating as a
   result of a grab, the device remains floating once the grab
   deactivates.

   If owner_events is False, all generated device events are
   reported with respect to grab_window if selected. If
   owner_events is True and if a generated device event would
   normally be reported to this client, it is reported normally;
   otherwise, the event is reported with respect to the
   grab_window, and is only reported if specified in the event
   mask.

   If the grab_mode argument is XIGrabModeAsync, device event
   processing continues as usual. If the device is currently
   frozen by this client, then processing of device events is
   resumed. If the grab_mode argument is XIGrabModeSync, the state
   of the device (as seen by client applications) appears to
   freeze, and the X server generates no further device events
   until the grabbing client issues a releasing XIAllowEvents call
   or until the device grab is released. Actual device changes are
   not lost while the device is frozen; they are simply queued in
   the server for later processing.

   If paired_device_mode is XIGrabModeAsync, processing of events
   from the paired master device is unaffected by activation of
   the grab. If paired_device_mode is XIGrabModeSync, the state of
   the paired master device (as seen by client applications)
   appears to freeze, and the X server generates no further events
   from this device until the grabbing client issues a releasing
   XIAllowEvents call or until the device grab is released. Actual
   events are not lost while the devices are frozen; they are
   simply queued in the server for later processing. If the device
   is a slave device paired_device_mode is ignored.

   If the device is actively grabbed by some other client,
   XIGrabDevice fails and returns AlreadyGrabbed. If grab_window
   is not viewable, it fails and returns GrabNotViewable. If the
   device is frozen by an active grab of another client, it fails
   and returns GrabFrozen. If the specified time is earlier than
   the last-device-grab time or later than the current X server
   time, it fails and returns GrabInvalidTime. Otherwise, the
   last-device-grab time is set to the specified time. CurrentTime
   is replaced by the current X server time.

   If cursor is not None this cursor is displayed until the client
   calls XIUngrabDevice.

   XIGrabDevice can generate BadDevice, BadValue, and BadWindow
   errors.

   The XIUngrabDevice request releases the device and any queued
   events if this client has it actively grabbed from either
   XIGrabDevice or XIGrabKey or XIGrabButton. If other devices are
   frozen by the grab, XUngrabDevice thaws them. XUngrabDevice
   does not release the device and any queued events if the
   specified time is earlier than the last-device-grab time or is
   later than the current X server time. The X server
   automatically performs an XIUngrabDevice request if the event
   window for an active device grab becomes not viewable.

   XIUngrabDevice can generate a BadDevice error.

DIAGNOSTICS
-----------

   BadValue
          A value is outside of the permitted range.

   BadDevice
          An invalid device was specified. The device does not
          exist or is not a appropriate for the type of change.

   BadMatch
          The window is not viewable.

   BadWindow
          A value for a Window argument does not name a defined
          Window.

BUGS
----

   The protocol headers for XI 2.0 did not provide
   XIGrabModeAsync or XIGrabModeSync. Use GrabModeSync and
   GrabModeAsync instead, respectively.

SEE ALSO
--------
   XIAllowEvents(libmansuffix)