Nevron Open Vision Documentation
Keyboard Input

 
About NKeyboard
The NKeyboard static class manages the keyboard virtual device in NOV and serves as UI event dispatcher for native keyboard events, that a particular window peer receives. Following is a description of the keyboard related features and services:
Events
Event Description Event Arguments

Keyboard Action Events

NKeyboard.KeyDownEvent Raised when a keyboard key is pressed. The target is the current keyboard focus target. The event is routed along the entire route from the target node to its root.  NKeyEventArgs
NKeyboard.KeyUpEvent Raised when a keyboard key is released. The target is the current keyboard focus target. The event is routed along the entire route from the target node to its root.  NKeyEventArgs
NKeyboard.InputCharEvent Raised when a keyboard key(s) gesture is recognized as an Unicode input character. The target is the current keyboard focus target. The event is routed along the entire route from the target node to its root.  NInputCharEventArgs

Keyboard Focus Target Events

NKeyboard.GotFocusEvent Raised when the keyboard is focused on a specific target. Further Keyboard Action Events will be raised for the focus target until the keyboard focus is moved to another target. The event is routed along the entire route from the target node to its root.  NFocusChangeEventArgs
NKeyboard.FocusInEvent Raised after NKeyboard.GotFocusEvent, but routed up to the last ancestor that was common between the previous focus target and the new one. NFocusChangeEventArgs
NKeyboard.FocusOutEvent Raised before NKeyboard.LostFocusEvent, but routed up to the last ancestor that was common between the previous focus target and the new one. NFocusChangeEventArgs
NKeyboard.LostFocusEvent Raised when a target looses keyboard focus. The event is routed along the entire route from the target node to its root.  NFocusChangeEventArgs
Extended Properties
Property Description
NKeyboard.FocusedPropertyEx Set to true for the input target on which has the keyboard focus.
NKeyboard.FocusWithinPropertyEx Set to true for the input target on which has the keyboard focus and all of its ancestors.
Keyboard Focus
Keyboard focus has two aspects – native and virtual. In order for an input target to actually gain keyboard focus, the peer of the window in which it resides must first gain native keyboard focus (i.e. the keyboard must first be focused in the native presentation layer). The part of the keyboard focus that deals with the actual window peer keyboard focus is referred as native keyboard focus. When native keyboard focus is obtained, all keyboard action events are natively routed to the window of the input target. Since NKeyboard is the front end for all keyboard events that arrive in NOV, it additionally redispatches the events to the current input target that has keyboard focus. This part of keyboard focus is referred as virtual keyboard focus, since the native presentation layer plays no role in this process. You typically never deal directly with the keyboard focus abilities of NKeyboard, but rather use the methods of the class (see Input Elements for more info).
Ambient Information

At any time you can obtain the state of the modifier keys (Ctrl, Alt and Shift), via the following properties:

 

The NKeyboard also provides several methods for helping you obtain the current value of the extended properties that it has applied to a particular node. These are:

 

 

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