Re: tab-bar: Defining another mouse-button binding?

[Juri Linkov]

> The real message text is
>
>   <nil> <wheel-down> is undefined
>
> and similarly for wheel-up.

Thanks for clarification.  Actually, there is already such bindings:

    (define-key map [wheel-up]    'tab-previous)
    (define-key map [wheel-down]  'tab-next)

So the problem is that it emits <nil> instead of <tab-bar>.
And as I understand, the same <nil> is emitted on the tab-line
instead of <tab-line> on GUI frames and on TTY frames.