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.
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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.
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The confine_to window (if any) is viewable.
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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.