int XGrabDeviceButton(Display *display, XDevice *device,
unsigned int button, 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 XUngrabDeviceButton(Display *display, XDevice *device,
unsigned int button, unsigned int modifiers, XDevice
*modifier_device, Window grab_window);
ARGUMENTS
display
Specifies the connection to the X server.
device
Specifies the device that is to be grabbed or released
button
Specifies the device button that is to be grabbed or released or
AnyButton.
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 the modifier_device
specified is NULL, 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 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 all other devices.
You can pass GrabModeSync or GrabModeAsync.
DESCRIPTION
The XGrabDeviceButton request establishes a passive grab.
In the future,
the device is actively grabbed (as for XGrabDevice,
the last-grab time is set to the time at which the button was pressed
(as transmitted in the
DeviceButtonPress
event), and the
DeviceButtonPress
event is reported if all of the following conditions are true:
*
The device is not grabbed, and the specified button is logically pressed
when the specified modifier keys are logically down on the specified
modifier device
and no other buttons or modifier keys are logically down.
*
Either the grab window is an ancestor of (or is) the focus window, OR
the grab window is a descendent of the focus window and contains the
device.
*
A passive grab on the same button/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 all buttons released
(independent of the logical state of the modifier keys).
Note that the logical state of a device (as seen by client applications)
may lag the physical state if device event processing is frozen.
This request overrides all previous grabs by the same client on the same
button/modifier combinations on the same window.
A modifiers 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 button of
AnyButton
is equivalent to
issuing the request for all possible buttons.
Otherwise, it is not required that the specified button currently be assigned
to a physical button.
A modifier_device of NULL indicates that the X keyboard is to be used as the
modifier_device.
If some other client has already issued a
XGrabDeviceButton
with the same button/modifier combination on the same window, a
BadAccess
error results.
When using
AnyModifier
or
AnyButton ,
the request fails completely,
and a
BadAccess
error results (no grabs are
established) if there is a conflicting grab for any combination.
XGrabDeviceButton
has no effect on an active grab.
XGrabDeviceButton
can generate
BadClass,
BadDevice,
BadMatch,
BadValue,
and
BadWindow
errors.
The XUngrabDeviceButton
request releases the passive grab for a
button/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 button of
AnyButton
is equivalent to issuing the
request for all possible buttons.
XUngrabDeviceButton
has no effect on an active grab.
A modifier_device of NULL indicates that the X keyboard should be used as
the modifier_device.
XUngrabDeviceButton
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 XGrabDeviceButton request was made
specifying
a device that has no buttons, or specifying 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.
