ntp_titler

Simple browser extension adding a window prefix to "special" tabs

Function

The prefix is determined by the type of the page. The prefix is determined matching the page url against the following in top-to-bottom order (first match applies)

NewTab - : The page the user has selected as their newtab page
Home - : The page the user has selected as their home page
PrivateBrowsing - : about:privatebrowsing (default newtab page for private windows)
Blank - : about:blank
<no-prefix> : https pages
chromeUI - : any other about: or chrome:// url
If the page doesn't fit into any of the above categories then it will be prefix by <url-scheme> -

Examples:

If the user has selected "blank page" as their homepage then loading about:blank will receive "Home - " prefix
If the user loads any http: url then it will receive http - prefix
If the user has set some extension page as their newtab, and they navigate to about:newtab then it will receive chromeUI - prefix

What is this useful for?

Honestly? Probably not much - except if you are into userChrome.css customization. This extension allows setting a "active tab type" as a prefix to the window. Luckily, Firefox (currently) stores the prefix in such a way that it can be used to conditionally style the window based on what type of tab is active. For example, you could show/hide various toolbars or buttons based on if the active tab is newtab page. Or you could make the UI bright red if the active page is using unsecured http connection.

Some selectors for use in userChrome.css

:root[titlepreface="http - "] 
:root[titlepreface="chromeUI - "]
:root[titlepreface="NewTab - "]
:root[titlepreface="Home - "]
:root[titlepreface="Blank - "]
:root[titlepreface="PrivateBrowsing - "]
:root[titlepreface="moz-extension - "]

Note that https: pages don't get any prefix - unless the particular url is set as your home or newtab page.

Also, there is no particular reason to believe that Firefox will always store the prefix in window element in such a way that this information is usable in userChrome.css. That's just how Firefox works right now, but it isn't in any way part of officially supported webextensions API.

Known problems

Firefox needs to be restarted after newtab or homepage have been modified for lableing to work properly.
about:blank causes an issue where either Blank, NewTab or Home will be shown as a prefix until switching tabs or loading a new page in the current tab. This happens because about:blank can be briefly loaded before the actual page content.

MrOtherGuy / ntp_titler