I have an addon here to control the master volume channel of my notebook. No problem to switch from js c-types to native message but what shall i do with the slider element in the addon bar?
slider element in the addon bar
Unless users have the Classic Theme Restorer, there hasn’t been an “addon bar” for quite some time, and I don’t think the things in the addon bar are called “sidebar elements”. So what exactly is it you want?
Firefox 54 does support sidebars, if that is what you are looking for:
Yes, i remember the removal of the addon bar or also former called statusbar was also such a design fail. I have totally forgotten in the meantime that this was also added by an addon now.
So there is a 2nd problem. A sidebar will not meet this requirement. A possibility to create a toolbar with webextension would be needed here. So there is https://bugzilla.mozilla.org/show_bug.cgi?id=1215064 to address this and there are only 4 months until legacy addons stop to work and no progress on this bug.
In the meantime i can play with the mentioned experiment API https://github.com/mixedpuppy/web-ext-toolbar.
the removal of the addon bar […] was also such a design fail.
While I agree that the timetable of the legacy add-on deprecation is too tight, I wouldn’t say that the removal of the status bar was such a bad idea. Personally, I think it’s a waste of screen space.
It was always possible to disable the addon/status bar for every one so where should be the problem to keep it? It is always the same, some people need it and some not. But with Webextensions we could not yet access this now, it is only one problem more at the moment.
I wouldn’t claim to be an expert, but I guess the reason for that UX dragon is that, if it is still in Firefox by default, add-ons will use it, possibly unhiding it upon installation. The user removed that add-on, the bar is still there, the user is confused and uses Chrome instead, because that browser doesn’t have that unholy bar.
It’s sad, but as a UX designer of a mass market product, you pretty much always have to assume that users are stupid.