search

arkenfox / user.js

Firefox privacy, security and anti-tracking: a comprehensive user.js template for configuration and hardening
MIT License
10.03k stars 514 forks source link

border around webpages [invalid: RTFM and duplicate of 679 - letterboxing] #728

Closed hollunder closed 5 years ago

hollunder commented 5 years ago

Hi there. I just spent a lot of time tracking down why I suddenly had a white border around every page after updating to Firefox 67. Eventually I tracked it down to this preference.

It's a rather invasive optical change and hence I don't think it's a great idea to have this enabled by default.

I suppose it's intended to make canvas fingerprinting harder, but my understanding is that the dimensions are just a small part of that and that there may be other and better ways to combat that practice.

Thorin-Oakenpants commented 5 years ago

So that's OK then. The JS values are exact, so when at round hundreds you won't see any letterboxing. The CSS is just quirky with "scaling" (not sure what that means exactly: do you mean zoom? RFP sets every new tab to zoom 100%: makes sense that zoom figures and rounding will cause the odd quirk: but we would probably all be the same), and was simply a means I used to help you find some the measurements to work out your chrome dimensions for the extension.

You can also work it out by the instructions in the user.js 4500 section header near the top

[NOTE] Info only: To set a size, open a XUL (chrome) page (such as about:config) which is at
100% zoom, hit Shift+F4 to open the scratchpad, type window.resizeTo(1366,768), hit Ctrl+R to run.
Test your window size, do some math, resize to allow for all the non inner window elements
jingofett commented 5 years ago

Sorry, scaling is a Windows 10 option. It increases the DPI

Thorin-Oakenpants commented 5 years ago

Ahh OK. I wasn't sure. I should stay away when I'm neck deep in other things, or at least clear my head. It kind of threw me, because 96dpi is "standard", and then you talked about preset "scaling", which is also what zoom comes with (but not those exact sizes, which I realized, but didn't put 2 and 2 together). Scaling (and DPI) can affects all sorts of things: it's a really big factor in entropy in things like clientRect. The good news is that LB seems to work ok.

jingofett commented 5 years ago

The only reason I figured it out was because you mentioned zoom levels, which I then remembered I was using on the OS-level.

I am realizing I only checked the DPI with Firefox, which probably faked the display of my DPI, checking with a non-hardened browser shows I'm using 120 DPI.

At any rate, thanks for the help and all the work you put into this!

Thorin-Oakenpants commented 5 years ago

holy moly ... looks like someone read the wiki page - https://old.reddit.com/r/privacytoolsIO/comments/c8v63e/ghacksuserjs_has_border_around_websites/