Is there a way to clear text that the player has typed into the input window but hasn't yet entered? I've been looking around at the likely extensions (e.g., "Text Input-Output Control," "Flexible Windows," etc) & their source code, but haven't come up with a way.
Could you clarify a couple of things?
I take it that you are using separate windows for text input and output?
Are you wanting to clear partial input in response to a real-time event, or in response to a specific keypress, or...?
The other thing I'm wondering is if there is an easy way to disable the command history that the player can access using the the up-arrow key? I was looking at the "Interactive Parser" extension source code and figure I could borrow from Jon Ingold's method of replacing the Keyboard Primitive--but I'm hoping there's an easier way.
The up/down arrow behavior is controlled by the interpreter, so the only way to get control is indeed to replace KeyboardPrimitive(), as Jon does with Interactive Parser. If the game is for a gallery piece (or any other situation where you control the computer on which it is displayed), I suppose that it might also be possible to disable the up/down arrow keys at the OS level.