Open Bug 1765171 Opened 3 years ago Updated 4 months ago

Undesired window shadows with browser.tabs.inTitlebar = 1 on KDE Plasma

Categories

(Core :: Widget: Gtk, defect, P3)

Product:
Core
Component:
Widget: Gtk
Version:
Firefox 101
Platform:
Desktop
Linux
Type:
defect

Tracking

()

Status:
UNCONFIRMED

People

(Reporter: tustamido, Unassigned)

References

(Blocks 1 open bug)

Details

On Linux, Firefox displays titlebar by default. I don't like it, so I use browser.tabs.inTitlebar = 1. But then the window has shadows even while my OS is configured to not have any shadow.

I use Linux with KDE Plasma 5.24.4, X11.

Steps to reproduce:

  1. System Settings → Appearance → Window Decorations, click edit in Breeze (default theme), Shadows → Size = None. This should remove shadows for every window.
  2. Open Firefox non maximized and with visible titlebar (browser.tabs.inTitlebar = 0 or 2). Window has no shadows, which is correct. screenshot
  3. Set browser.tabs.inTitlebar = 1 in about:config to remove titlebar. Now Firefox window bypass my OS configuration and displays unwanted shadows. screenshot

This was reported to KDE and rejected, devs said it's a Firefox issue, because browser.tabs.inTitlebar = 1 makes Firefox to decorate window by itself instead of leaving it to OS.

Is that a recent regression or have you seen that before? How do other Gtk applications (like gedit) behave?

Blocks: gtktitlebar
Flags: needinfo?(tustamido)
Priority: -- → P3

It's not a recent regression, did a quick try with mozregression chosing versions 60 and 91 and both have the issue.

Other GTK apps don't have this issue. Just like Firefox if you don't disable titlebar. As I said, the issue here is that when you disable titlebar with browser.tabs.inTitlebar = 1 Firefox forces window decorations to be done by itself instead of the OS, that's why only Fx is affected.

So in that case Fx must get OS settings about windows shadows and follow them. This is correctly done on Windows 10. In there, even with Firefox's titlebar disabled (it's Fx default on every OS except Linux - why?), Fx window only displays shadows if you have Show shadows under windows enabled in W10 Performance Options.

But on KDE Plasma Firefox doesn't honors my (non-)shadows preference. I can't say about how it is on other DEs, didn't test. It may be hard to add a compatibility layer for every existing DE, but I guess KDE and GNOME are major ones that deserve care.

Flags: needinfo?(tustamido)

Since shortly ago (maybe v98 or even v100), Firefox doesn’t let kwin draw the shadows anymore, which means that

  1. they are a different size and color than what I configured
  2. they aren’t clickthrough, so when I click closely next to firefox’ window, firefox gets activated instead of the window I clicked

On Linux (NixOS) with KDE Plasma 5.27.1 and Firefox 110.0, I'm having the same issue. When the titlebar is disabled, window shadows are drawn, despite shadows being via KDE's system settings at Appearance => Window Decorations.

A workaround I'm using is to disable shadows for all GTK3 windows in $HOME/.config/gtk-3.0/gtk.css.

decoration { box-shadow: none; }

Also running into this issue and and causes the viewport to be offset because of it. Setting the decoration as a gtk override as seen above fixes the issue visually but not when interacting (the viewport is still offset).

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