Widget handler: OnKeyDown
Description
The OnKeyDown handler is called when the user first hits a key and this frame is registered for keyboard events with Frame:EnableKeyboard. See also OnKeyUp.
Note that if you think you want to use this handler to take an in-game action based on a keypress, you probably really want to enable the runOnUp attribute of a key binding, and check the keystate variable and act accordingly. See HOWTO: Use Bindings.xml to create key bindings for your AddOn. This handler is more appropriate for cases where you want to allow freeform text entry and an EditBox isn't flexible enough.
Arguments
arg1 - returned as a string representing the key that was pressed. For example, "W" or "A" or "S" or "D" (main keyboard keys) or "UP" or "LEFT" or "DOWN" or "RIGHT" (arrow keys) or "DELETE" or other extended keys or "SHIFT" or other modifier keys.