Re: Disabling show-wspace for a specific mode or buffer

[Michael Heerdegen <michael_heerdegen@web.de>]

"Drew Adams" <drew.adams@oracle.com> writes:

> > (add-hook 'font-lock-mode-hook 'show-ws-highlight-tabs)
> > (add-hook 'font-lock-mode-hook 'show-ws-highlight-trailing-whitespace)
> > 
> > My problem is that in 99% of buffers I want this behavior, but
> > sometimes I don't. For example, when I run the command M-x w3m to
> > browse the web, I don't want to see trailing whitespace highlighted.
> > Can anyone suggest a solution for this problem?
>
> Sorry, but there is no simple way to do that.  But you can do it in this
> roundabout way (ugly!):
>
> (add-hook 'change-major-mode-hook
>           (lambda ()
>             (add-hook 'font-lock-mode-hook
>                       'show-ws-highlight-trailing-whitespace)))
>
> (add-hook 'after-change-major-mode-hook
>           (lambda ()
>             (when (eq major-mode 'THE-MODE)
>               (remove-hook 'font-lock-mode-hook
>                            'show-ws-highlight-trailing-whitespace)
>               (show-ws-dont-highlight-trailing-whitespace)))
>           'append)

Maybe an alternative approach would be to add the highlighting functions
to the text-mode-hook:

(add-hook 'text-mode-hook 'show-ws-highlight-tabs)
(add-hook 'text-mode-hook 'show-ws-highlight-trailing-whitespace)

Since most editing modes run `text-mode-hook', and other modes don't,
maybe this way you can get along with less exceptions?  Just an idea.


Michael.