Extensions

If you’re serious about improving your application’s performance, you need to collect data. At Mozilla, we use Talos. The Mobile team has been using Talos to track performance on Maemo (using N810 and N900) devices for a few years and recently started tracking Android (using Tegras) as well. Here are a few of the metrics we track:

I saw a neat technique in Bug 564675 for creating default preferences in bootstrapped add-ons. Edward Lee posted a link to some code he uses for a bootstrapped add-on. Essentailly, the default preference branch is writable, but not permanent. This is a good thing for bootstrapped add-ons. The add-on should write it’s default preferences every time it loads and the preferences disappear when the session ends. The code looks like:

After playing around with bootstrap (restartless) add-ons a bit more, I came to the point where I needed some extra resources in the add-on. For images, I could have stuck with the data: URI approach I mentioned previously, but I also wanted to add an options UI for my add-on. Turns out it was pretty simple. Thanks to Vlad for getting the ball rolling.

Just an update for add-on developers who are targeting Firefox Mobile. AMO (addons.mozilla.org) is ready for you to bump MaxVersion to “4.0b4”

Last week we were talking about the need for [private browsing](http://support.mozilla.com/en-US/kb/Private Browsing), or something like it, in Firefox Mobile. Even though you might not share your phone with other people, you might share a tablet - especially the “family tablet”, sitting there on the coffee table. Private browsing is an obtrusive system, at least as implemented in Mozilla, and it’s doubtful we could add it for Firefox Mobile in time for the upcoming release. Also, private browsing doesn’t really satisfy the sharing use case for tablets.

We recently landed some code in Firefox Mobile to better handle restartless (bootstrapped) add-ons. Turns out, Dietrich made a non-Jetpack add-on using the SDK and tried unsuccessfully to install it into Firefox Mobile. In the process of getting everything working, I decided to make a simple restartless add-on we could use as a testcase. It’s a copy of Dietrich’s original add-on, without any SDK usage. I’ve not taken the SDK plunge yet. The experience was interesting, educational and slightly enjoyable. The process of testing the install / uninstall and enable / disable mechanism without a restart left me as giddy as a schoolboy.

In addition to working on Firefox Mobile, I like to tinker around with building add-ons too. Not surprising I guess, since I seem to go on and on about how to build them.