XGRABDEVICEKEY
Section: \ \& (3)
Updated: 06/19/2019
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NAME
XGrabDeviceKey, XUngrabDeviceKey - grab/ungrab extension input device Keys
SYNOPSIS
#include <X11/extensions/XInput.h>
int XGrabDeviceKey( Display *display,
XDevice *device,
unsigned int key,
unsigned int modifiers,
XDevice *modifier_device,
Window grab_window,
Bool owner_events,
unsigned int event_count,
XEventClass *event_list,
int this_device_mode,
int other_devices_mode);
int XUngrabDeviceKey( Display *display,
XDevice *device,
unsigned int key,
unsigned int modifiers,
XDevice *modifier_device,
Window grab_window);
display
Specifies the connection to the X server.
device
Specifies the device that is to be grabbed or released.
Key
Specifies the device Key that is to be grabbed released
or AnyKey.
modifiers
Specifies the set of keymasks or AnyModifier.The mask is
the bitwise inclusive OR of the valid keymask bits.Valid
bits are: ShiftMask, LockMask, ControlMask, Mod1Mask,
Mod2Mask,Mod3Mask, Mod4Mask, Mod5Mask.
modifier_device
Specifies the device whose modifiers are to be used. If
a modifier_device of NULL is specified, the X keyboard
will be used as the modifier_device.
grab_window
Specifies the grab window.
owner_events
Specifies a Boolean value that indicates whether the
device events are to be reported as usual or reported
with respect to the grab window if selected by the event
list.
event_count
Specifies the number of event classes in the event list.
event_list
Specifies which device events are reported to the
client.
this_device_mode
Specifies further processing of events from this
device. You can pass GrabModeSync or GrabModeAsync.
other_devices_mode
Specifies further processing of events from other
devices. You can pass GrabModeSyncor GrabModeAsync.
DESCRIPTION
-
The XGrabDeviceKey request establishes a passive grab. In the
future, the device is actively grabbed (as for XGrabDevice, the
last-device-grab time is set to the time at which the Key was
pressed (as transmitted in the DeviceKeyPress event), and the
DeviceKeyPress event is reported if all of the following
conditions are true:
* The device is not grabbed, and the specified key is
logically pressed when the specified modifier keys are
logically down, and no other keys or modifier keys are
logically down.
* The grab_window is an ancestor (or is) the focus window OR
the grab window is a descendant of the focus window and
contains the device.
* The confine_to window (if any) is viewable.
* A passive grab on the same key/modifier combination does
not exist on any ancestor of grab_window.
-
The interpretation of the remaining arguments is as for
XGrabDevice. The active grab is terminated automatically when
the logical state of the device has the specified key released.
-
Note that the logical state of a device (as seen by means of
the X protocol ) may lag the physical state if device event
processing is frozen.
-
If the key is not AnyKey, it must be in the range specified by
min_keycode and max_keycode as returned by the
XListInputDevices request. Otherwise, a BadValue error results.
-
This request overrides all previous grabs by the same client on
the same Key/modifier combinations on the same window. A
modifier of AnyModifier is equivalent to issuing the grab
request for all possible modifier combinations (including the
combination of no modifiers). It is not required that all
modifiers specified have currently assigned KeyCodes. A key of
AnyKey is equivalent to issuing the request for all possible
keys. Otherwise, it is not required that the specified key
currently be assigned to a physical Key.
-
If a modifier_device of NULL is specified, the X keyboard will
be used as the modifier_device.
-
If some other client has already issued a XGrabDeviceKey with
the same Key/modifier combination on the same window, a
BadAccess error results. When using AnyModifier or AnyKey, the
request fails completely, and a BadAccess error results (no
grabs are established) if there is a conflicting grab for any
combination.XGrabDeviceKey has no effect on an active grab.
-
XGrabDeviceKey can generate BadAccess, BadClass, BadDevice,
BadMatch, BadValue, and BadWindow errors. It returns Success on
successful completion of the request.
-
The XUngrabDeviceKey request releases the passive grab for a
key/modifier combination on the specified window if it was
grabbed by this client. A modifier of AnyModifier is equivalent
to issuing the ungrab request for all possible modifier
combinations, including the combination of no modifiers. A Key
of AnyKey is equivalent to issuing the request for all possible
Keys.XUngrabDeviceKey has no effect on an active grab.
-
If a modifier_device of NULL is specified, the X keyboard will
be used as the modifier_device.
-
XUngrabDeviceKey can generate BadDevice, BadMatch, BadValue and
BadWindow errors.
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.
-
BadMatch
This error may occur if an XGrabDeviceKey request was
made specifying a device that has no keys, or a modifier
device that has no keys.
-
BadValue
Some numeric value falls outside the range of values
accepted by the request. Unless a specific range is
specified for an argument, the full range defined by the
argument's type is accepted. Any argument defined as a
set of alternatives can generate this error.
-
BadWindow
A value for a Window argument does not name a defined
Window.
SEE ALSO
-
XAllowDeviceEvents(3), XGrabDevice(3), XGrabDeviceButton(3)