Rails testing and Emacs mode line

I’ve been diving/digging into the oh-so-excellent Rails Tutorial, by Michael Hartl, and am into chapter 3, where testing begins.

Imagine my surprise — go ahead, imagine it — when my Emacs mode line changed color.

Originally:

modeline_original

And when I ran “bundle exec rake test”, it succeeded with:

modeline_success

Then changing the test code to fail, after running “bundle exec rake test” again:

modeline_failed

Tracking down this code, I found that the guard-notiffany gem was doing this behavior, sending a change to the Emacs mode line via emacsclient, with this bit of code in lib/notiffany/notifier/emacs.rb:

        def notify(color, bgcolor)
          elisp = <<-EOF.gsub(/\s+/, " ").strip
            (set-face-attribute 'mode-line nil
                 :background "#{bgcolor}"
                 :foreground "#{color}")
          EOF
          emacs_eval(elisp)
        end

The issue there was that it just changes the mode line “permanently”. I’d prefer that the mode line colors change for a moment, then time out and revert to their previous settings.

I wrote a bit of code to do this, and modified lib/notiffany/notifier/emacs.rb locally, but there is a pending pull request that has a better implementation.

However, my hack is:

        def notify(color, bgcolor)
          elisp  = "(let ((orig-bg (face-attribute 'mode-line :background))"
          elisp << "      (orig-fg (face-attribute 'mode-line :foreground)))"
          elisp << "     (set-face-attribute 'mode-line nil"
          elisp << "                         :background \"#{bgcolor}\""
          elisp << "                         :foreground \"#{color}\")"
          elisp << "     (sit-for 3)"
          elisp << "     (set-face-attribute 'mode-line nil"
          elisp << "                         :background orig-bg"
          elisp << "                         :foreground orig-fg))"
          emacs_eval(elisp)
        end

The sit-for keeps the mode line as red or green for 3 seconds or when there is Emacs input. I prefer that, to clear the mode line more quickly, since I find the bright color distracting.

Advertisements

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s