XGrabDeviceKey(3)

NAME
XGrabDeviceKey, XUngrabDeviceKey - grab/ungrab extension input device Keys

SYNTAX

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);

ARGUMENTS

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 or 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 GrabModeSync or 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),
Programming with Xlib