Photon Engineering Newsletter #7

Lucky you, here’s Photon update #7!

Let’s start off with a fresh new video that gives an overview of what we’re doing with the Quantum and Photon projects. If you’re not already running Nightly, but are willing to live on the cutting-edge, this would be a great time to give it a spin! Get involved to help us test out everything that’s new, and experience some of these great improvements first-hand!


Mozilla All-Hands

Next week, everyone at Mozilla will be gathering in San Francisco for our biannual All-Hands meeting. The Photon team will be using it as a repeat of our Toronto Work Week (as covered in Photon Update #2). So we’re going to be super-busy hacking on Photon. We’ve got even more great stuff coming up, and I can’t wait to talk about it in Photon Update #8. But… The intense focus means that I might not get that update out until the following week. I think the wait will be worth it. 🙂


Recent Changes




  • Updated arrow-panel animations are going through review this week.
  • Users on macOS will notice that panel open/close animations are much smoother, as a result of a platform fix. (You’ll see more improvements soon, from the item above, as well as another platform fix to add a beautiful background blur to the panel).
  • Work continues on animations for the downloads toolbar button, stop/reload button, and page loading indicator.




Visual redesign:

  • Another community contribution: Oriol removed an small, unexpected line that was appearing at the top of some windows. Thanks for the patch!
  • Firefox will now automatically enable its touch mode (which increases the size of various UI to make it more touch-friendly) when used in Windows 10 Tablet mode.
  • The dark toolbar that previously landed for Windows 10 is now coming to macOS. (This just landed, and if it sticks will be in Friday’s Nightly build.)
    Screen Shot 2017-06-22 at 4.27.25 PM



  • The onboarding tour content has landed and been polished to match the UI spec. You can click the Fox icon in about:home to give it a try! Currently it has 5 tours for existing (non-Photon) features — Private Browsing, Add-ons, Customization, Searching, and setting your Default Browser. These are planned to ship in Firefox 56 (for users installing Firefox for the first time). Additional tours will next be implemented for Firefox 57, to introduce new Photon features to existing Firefox users.
  • The onboarding tour now has UI to allow hiding it (so users who don’t want to go through each tour step can just make it go away).
  • The Mozilla logo and onboarding icon are now shown on the correct sides for RTL languages.
  • A Sync tour and tour notifications will be landing soon.



  • Places (our bookmarks and history storage system) is now initialized after first paint on startup. This helps make Firefox feel faster to launch, because the window will be shown sooner.
  • More giant patches up for review for removal of Task.jsm calls, and fixed the last blocker to starting work on removing Promise.jsm usage.
  • More awesome work on improving Talos measurements and figuring out regressions. (Particularly some issues that have been holding up animations.)
  • Florian posted in firefox-dev about the browser_startup.js test, and asked everybody to have a look at the generated list to identify low hanging fruit. This test helps us find code that is loading too early, and prevents things from regressing once we fix it.


Thus concludes Photon update #7. As noted above, next week is going to be a little busy, so it may be a couple of weeks until the next update.

4 thoughts on “Photon Engineering Newsletter #7”

  1. Please incorporate click-to-play for HTML5 Video, or a blacklist/whitelist system for site permissions.

    Autoplay video is a menace!

    1. Firefox 54 just shipped one improvement here — media won’t play until you select a tab for the first time. I believe we’re looking at some additional things, but they’re not part of the Photon/Quantum goals.

      Improving permission management is also an area we’re working on soon, but also isn’t part of the Photon/Quantum scope.

Comments are closed.