With the new Firefox 4 release mozilla has introduced some interesting new features and improvements. Particularly the changes to the GUI are interesting. Now you can pin a Tab as "App Tab" and so the tab is pinned on the left side of the tab-panel and you only see the favicon of this tab. I really like this for applications like google mail and google calender but also for news pages I regularly read.
But there are also problems with this approach. Sometimes I forget that I'm in an AppTab and that I don't want to switch to another page in this Tab. But because I have the URL-bar available it happens that I found another page in the Tab where my "App" should be.
Another issue is that the main goal of the AppTabs is saving space. To support this, wouldn't it be cool to hide the URL-bar and other toolbars when you are in an AppTab? You also couldn't change the location by accident. This is what I thought and so I begun to write a little extension to enable this.
Happily mozilla introduced a technique to do exactly this. For example when you open the new Addon-Manager you see that it is opened in a new tab. If you have set your tabpanel to be on top of the URL-bar you will see the toolbars hidden when you are inside of the Addon-Manager-tab. You can use this technique for every page you want ... at least on paper. Sadly there is no GUI with which you could enable hiding for a specified URL. This is what my extension is doing.
With my extension "Hide Toolbars by URL" you have a new entry in the context menu of every tab with which you can hide this URL. The hiding is connected to the URL, not to the tab. So if you open the same URL in another tab it will also be hidden. But because the exact URL will change when you use the page (i.e. when you follow a link on this domain you will be at another URL) it wouldn't be really cool. So only the first part of the URL is used to determine if the tab should be hidden. I only use "http://www.google.de" - everything behind is cut of. So every "subpage" of "http://www.google.de" will be hidden. I'm not sure if this approach is the bests so I would love to get feedback for this. Probably I will change this in the future.
Of cause the code is free and open source - you can get the code at github.com. There is also the xpi-file you need to install. I will give this extension to the addon-page of mozilla and probably they will add this to there page so you can easily install it the same way you install every extension.