by fabianswebworld (Developer) on Nov. 25, 2017 · permalink

...it’s planned, yet I cannot tell when it’s done. Moreover, due to the limitations of the WebExtension API over the old XUL API, I can’t promise that functionality will be exactly the same as before.

I’ll let you know by then!

//EDIT: 2017-11-29

Unfortunately, after much work of investigating different issues on the way to a WebExtension-compatible version of FLST, I found out that there will be NO way to port this Add-on to Firefox 57+. The new APIs simply don't provide the hooks, functions and events needed to implement the core functionality of tab-flipping by clicking the currently active tab (and I will not write an extension that doesn't offer this key feature, as it will be pointless for myself then).

If you want to learn about the details (and understand German), you can read my article about this here: www.fabianswebworld.de/?p=347

Long story short: there simply is no API to handle clicks or other events on the tab-bar itself. And as stated in Mozilla Bug #1246706 (https://bugzilla.mozilla.org/show_bug.cgi?id=1246706), which is in the "RESOLVED - WONTFIX" state, this is not going to be fixed/implemented later.

I am truly sorry to have to tell you this, and believe me - I am the person that is most upset about it myself. I recommend that you use Firefox ESR, which will support "Legacy Add-Ons" until June, 2018.

Sorry again for any inconveniences you may experience due to the fact that FLST will not continue to work in Firefox 57+, but please do not blame me - blame Mozilla for taking away the API that made this Add-on possible and not providing ANY interface that would make porting FLST possible.

As of now, it simply isn't.

Best regards,
Fabian