Hi kuopiofi, are you still running Firefox 56?!

In short, the "Toolbars API" for WebExtensions to modify whole bars has not been finalized, so you still need to use a userChrome.css file to modify the toolbar area.

I don't know if anyone has created a style rule to hide the tab bar when there's only one tab, or whether that requires information inaccessible to style rules. A good place to research that is: https://www.reddit.com/r/FirefoxCSS/

I'm not sure what you mean here:

I'm looking for one that would allow hiding the tab-bar when there's only one tab open (bit more space to use) and where the opened tabs go (to the end preferably).

By default, new tabs go to the end and "related" tabs -- for example, a link you click in the current tab -- open adjacent to the current tab. To change that:

(1) In a new tab, type or paste about:config in the address bar and press Enter/Return. Click the button promising to be careful or accepting the risk.

(2) In the search box above the list, type or paste insert and pause while the list is filtered

(3) By default, links in a tab will open next to the tab. This older preference is called browser.tabs.insertRelatedAfterCurrent and its default value is true -- double-click to toggle if desired

(4) By default, other new tabs open at the end of the bar. Starting in Firefox 61, you can change that using the browser.tabs.insertAfterCurrent preference, which has a default value of false -- double-click to toggle to true if desired

I found http://forums.mozillazine.org/viewtopic.php?f=38&t=3035293&p=14782211 for hiding the tab bar when there's only one tab. Could you take a look at it and check if it's still usable?

https://addons.mozilla.org/en-GB/firefox/addon/everything-right/?src=search seems to add all tabs to right end, so that's done.

Also found https://addons.mozilla.org/en-GB/firefox/addon/undoclosetabbutton/ undo close tab which I forgot to ask.

Well, after a bit of checking Everything Right seems to cause few problems so I used the way you suggested. Works fine.

Thanks.

kuopiofi said

I found http://forums.mozillazine.org/viewtopic.php?f=38&t=3035293&p=14782211 for hiding the tab bar when there's only one tab. Could you take a look at it and check if it's still usable?

You could try it. It's not something I would ever use myself.

Also found https://addons.mozilla.org/firefox/addon/undoclosetabbutton/ undo close tab which I forgot to ask.

Hmm, I guess if the tab bar is hidden, using right-click > Undo Close Tab on a tab wouldn't work. If you wanted to avoid another add-on, you could use the keyboard shortcut:

Ctrl+Shift+t (on Mac, Command+Shift+t)

or the Recently Closed Tabs list on the History menu.

or the Recently Closed Tabs list on the History menu.

Noticed that after posting the question...  ;-_-

That said, is there any way to clear the recently closed tabs or recently closed windows? Considering the number of closed tabs I tend to cause, I suspect that amount starts to take bit more memory than I like.

kuopiofi said

or the Recently Closed Tabs list on the History menu.

That said, is there any way to clear the recently closed tabs or recently closed windows? Considering the number of closed tabs I tend to cause, I suspect that amount starts to take bit more memory than I like.

By default, the Recently Closed Tabs list has a cap of 25 tabs per window. You can reduce (or increase) that in about:config --

(1) In a new tab, type or paste about:config in the address bar and press Enter/Return. Click the button accepting the risk.

(2) In the search box above the list, type or paste sess and pause while the list is filtered

(3) Double-click the browser.sessionstore.max_tabs_undo preference to display a dialog where you can enter the desired value, then click OK

That helps. Thanks.