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XGrabDeviceButton, XUngrabDeviceButton - grab/ungrab extension
input device buttons
- int XGrabDeviceButton(Display *display, XDevice *device,unsigned int button,
unsigned int modifiers, XDevice*modifier_device, Window grab_window, Boolowner_events,
unsigned int event_count, XEventClass*event_list, int this_device_mode,
intother_devices_mode); int XUngrabDeviceButton(Display *display, XDevice
*device,unsigned int button, unsigned int modifiers, XDevice*modifier_device,
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:
- Specifies the connection to the
- Specifies the device that is to be grabbed or released
- Specifies the device button that is to be grabbed or released or
- 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.
- specifies the device whose modifiers are to be used. If
the modifier_device specified is NULL, the X keyboard will be used as the
- Specifies the grab window.
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
- Specifies the number of event classes in the event
- Specifies which events are reported to the client.
- Specifies further processing of events from this device. You can pass GrabModeSync
- Specifies further processing of events
from all other devices. You can pass GrabModeSync or GrabModeAsync.
- 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.
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.
generate BadDevice, BadMatch, BadValue and BadWindow errors.
- 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.
- 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.
- 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.
- A value for a Window argument does not name a defined Window.
Programming With Xlib
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