Transparent macos-titlebar-style not honoured when background is close to black

[fionn]

When background = #0d0d0d (or brighter), the titlebar transparency works as expected.

When background = #0c0c0c (or darker), the titlebar is not transparent and behaves as if set to native.

Screenshots

[qwerasd205]

This looks like it's the effect of some code that was added in f086bff to make sure it's possible to distinguish the currently selected tab on very dark backgrounds. It could be handled more gracefully than this though.

[fionn]

I think it's these two assignments, conditional on backgroundColor.luminance < 0.05.

ghostty/macos/Sources/Features/Terminal/TerminalWindow.swift

Lines 554 to 555 in f086bff

	let highlightedColor = terminalWindow.hasVeryDarkBackground ? terminalWindow.backgroundColor : .clear
	let backgroundColor = terminalWindow.hasVeryDarkBackground ? titlebarBackgroundColor : systemOverlayColor

Selected tabs are distinguishable based on the colour of the title and indicator, so I think this isn't necessary -- especially given when macos-titlebar-style = tabs on a black background it works as expected.

[Absolpega]

this feels dumb
as a user I think I should be able to decide whether I can distinguish the tabs or not
there should at least be a warning in the man page about this

also one workaround is to set it to a bright value at launch but then change it back to a darker value and reload

[Fake-User]

I tried moving over from iterm, and this really stumped me for a hour till i found this issue. I had set my background to #000000 like I usually do, and couldn't figure out why macos-titlebar-style = transparent wasn't doing anything. changing the background to #0d0d0d or brighter does let the title bar be transparent, but its still not what i was hoping for.

[J-Siu]

@Fake-User Try:

theme = dark:iTerm2 Default,light:iTerm2 Default
background-opacity = 0.85
macos-titlebar-style = tabs

[Fake-User]

@J-Siu
seems to work correctly with macos-titlebar-style = tabs
many thanks