Firefox for Presentations: Hiding the URLbar (Shallow Thoughts)

Akkana's Musings on Open Source, Science, and Nature.

Tue, 25 Apr 2006

Firefox for Presentations: Hiding the URLbar

I've long been an advocate of making presentations in HTML rather than using more complex presentation software such as PowerPoint, Open Office Presenter, etc. For one thing, those presentation apps are rather heavyweight for my poor slow laptop. For another, you can put an HTML presentation on the web and everyone can see it right away, without needing to download the whole presentation and fire up extra software to see it.

The problem is that Mozilla's fullscreen mode doesn't give you an easy way to get rid of the URL/navigation bar, so your presentations look like you're showing web pages in a browser. That's fine for some audiences, but in some cases it looks a bit unpolished.

In the old Mozilla suite, I solved the problem by having a separate profile which I used only for presentations, in which I customized my browser to show no urlbar. But having separate profiles means you always have to specify one when you start up, and you can't quickly switch into presentation mode from a running browser. Surely there was a better way.

After some fruitless poking in the source, I decided to ask around on IRC, and Derek Pomery (nemo) came up with a wonderful CSS hack to do it. Just add one line to your chrome/userChrome.css file.

In Firefox:

#toolbar-menubar[moz-collapsed=true] + #nav-bar { display: none !important; }

In Seamonkey:

#main-menubar[moz-collapsed=true] + #nav-bar { display: none !important; }

This uses a nice CSS trick I hadn't seen before, adjacent sibling selectors, to set the visibility of one item based on the state of a sibling which appears earlier in the DOM tree.

(A tip for using the DOM Inspector to find out the names of items in fullscreen mode: since the menus are no longer visible, use Ctrl-Shift-I to bring up the DOM Inspector window. Then File->Inspect a Window and select the main content window, which gets you the chrome of the window, not just the content. Then you can explore the XUL hierarchy.)

This one-line CSS hack turns either Firefox or Seamonkey into an excellent presentation tool. If you haven't tried using HTML for presentations, I encourage you to try it. You may find that it has a lot of advantages over dedicated presentation software.

Addendum: I probably should have mentioned that View->Toolbars->Navigation Controls turns off the toolbar if you just need it for a one-time presentation or can't modify userChrome.css. You have to do it before you flip to fullscreen, of course, since the menus won't be there afterward, and then again when you flip back. I wasn't happy with this solution myself because of the two extra steps required every time, particularly because the steps are awkward since they require using the laptop's trackpad.

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[ 16:59 Apr 25, 2006    More tech/web | permalink to this entry ]