XGrabDeviceButton(3) X FUNCTIONS XGrabDeviceButton(3)
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, Bool
owner_events, unsigned int event_count, XEventClass
*event_list, int this_device_mode, int
int XUngrabDeviceButton(Display *display, XDevice *device,
unsigned int button, 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
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 inclu-
sive OR of the valid keymask bits. Valid bits are: Shiftmask, LockMask, Con-
trolMask, 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 modifier_device.
grab_window Specifies the grab window.
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.
Specifies further processing of events from this device. You can pass Grab-
ModeSync or GrabModeAsync.
Specifies further processing of events from all other devices. You can pass
GrabModeSync or GrabModeAsync.
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 DeviceButton-
Press event is reported if all of the following conditions are true:
o 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.
o 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.
o A passive grab on the same button/modifier combination does not exist on any ancestor
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 phys-
ical 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 modi-
fiers). 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. Oth-
erwise, it is not required that the specified button currently be assigned to a physical
A modifier_device of NULL indicates that the X keyboard is to be used as the modi-
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 Any-
Button , the request fails completely, and a BadAccess error results (no grabs are estab-
lished) 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
The XUngrabDeviceButton request releases the passive grab for a button/modifier combina-
tion 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
A modifier_device of NULL indicates that the X keyboard should be used as the modi-
XUngrabDeviceButton can generate BadDevice, BadMatch, BadValue and BadWindow errors.
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 alterna-
tives can generate this error.
BadWindow A value for a Window argument does not name a defined Window.
Programming With Xlib
X Version 11 libXi 1.2.1 XGrabDeviceButton(3)