[Icons] Paint neutral glyphs with icon ink instead of body-text ink

Neutral icons resolved `currentColor` straight to `QPalette::WindowText`. A
glyph is not a word: it is a 16-24px mark drawn with a 2-unit stroke, so
antialiasing thins it until it reads lighter than the text beside it, in the
one color the palette reserves for reading. The result is that icons recede
into the chrome exactly where they should anchor it.

Add `theme_icon_ink`, one rule with one job: mix a share of the theme accent
into the neutral text color, then hold the result to a contrast floor. The
accent share gives the glyph chroma the text does not have, so it reads as an
icon rather than as leftover text, and it is derived from `QPalette::Highlight`
rather than a new token. The floor keeps a theme with a weak text color from
producing an illegible glyph.

Only the neutral label roles (`WindowText`, `Text`) are inked. Semantic tints
are hues the call site chose on purpose, disabled uses the disabled group, and
the selected-row swap to `HighlightedText` is unchanged.

The WCAG contrast math moves from `theme_icon_badge` to the new unit, so badge
ink decisions and the floor share one implementation.

Tests: the ink rule against every shipped palette, the weak-text floor, and the
palette-following render tests now ask the rule instead of restating its
output. A preview sheet sweeps the accent share at 0-35% over window and button
surfaces for both schemes.
This commit is contained in:
Lukas Brübach 2026-11-06 23:02:58 +01:00
parent 4a0c956062
commit 86c8790b48
10 changed files with 467 additions and 36 deletions

View file

@ -68,6 +68,12 @@ public:
* color keeps the WindowText -> HighlightedText swap. Application colors go
* through the saturation floor shared by the filled treatments, so a line
* glyph, a badge disc and a sticker fill carry the same tone.
*
* Neutral label roles (WindowText, Text) resolve to icon ink rather than the
* raw palette color: ThemeIconInk::glyphInk borrows a little accent chroma
* and holds the glyph to a contrast floor, because a 2px glyph in body-text
* ink reads thinner than the text beside it. Semantic roles keep the hue the
* call site asked for.
*/
QColor resolve(QIcon::Mode mode) const;