Re: Physical keyboard events

[Cecilio Pardo <cpardo@imayhem.com>]

On 29/10/2024 14:40, Eli Zaretskii wrote:

>> I'm planning to implement physical key press/release events for emacs.
>> I would add a new element to 'enum event_kind', that in turn would
>> send a new input event. This input event will be bound in
>> 'special-event-map' so that it will not modify the normal flow of
>> keyboard input. Platform dependent code would send these events
>> on key press and release.
> 
> I hope these new events will not be sent at all times, only when some
> optional variable is set (similar to track-mouse, perhaps).  I
> wouldn't want Emacs to start processing press/release events on Shift
> or Ctrl unless a Lisp program needs that, and I don't think we want to
> change our processing of keyboard such that instead of a single
> keypress with modifiers we need to process multiple key-press and
> key-release events when the user simply types on the keyboard.

Thats why the events will be bound in special-event-map. Nobody will see 
them, except for the code that handles them.  We can of course 
completely disable them with a variable.

> Physical keys also raise the issue of supporting input methods,
> keyboard layout switches, etc.

I will define a list of keys: LeftShit, RightShift, LeftControl, etc. 
The platform dependent code will decide which one was pressed. As events 
will be invisible, I don't think we will interfere with input methods.

> However, on what systems and which Emacs configurations will it be
> possible to provide such a feature?

I think all GUI systems can use this.