feat(helium): switch to the GTK theme with KWin title buttons

Helium now takes its colors from Breeze GTK instead of a generated
theme extension, which reset the GTK theme on every launch.

- Import window_decorations.css from gtk.css so Helium, which doesn't
  load kde-gtk-config's GTK module, draws the KWin title buttons
  instead of Breeze GTK's round ones.
- Add chromium.css to give the compact layout's address bar and
  button segment the title bar color, so the tab strip is one color.
- Disable WaylandWpColorManagerV1 so KWin doesn't lift Helium's dark
  grays (40 -> 44) and the strip matches KDE title bars.
- Drop the Helium theme from build.py and the helium package.

kde/README.md

@@ -15,7 +15,7 @@ stow -d kde -t "$HOME" spectacle fastfetch
 | Package                            | Details                                                  |
 | ---------------------------------- | -------------------------------------------------------- |
 | [theme](theme/README.md)           | Darwin Breeze KDE colors and generated app themes        |
-| [helium](helium/README.md)         | Browser flags and the generated Helium theme             |
+| [helium](helium/README.md)         | Browser flags; colors come from GTK                      |
 | [fastfetch](fastfetch/README.md)   | Konsole configuration and a pre-scaled inline image logo |
 | [spectacle](spectacle/README.md)   | Screenshots to clipboard with a notification, no preview |
 | [tray-icons](tray-icons/README.md) | Ngó Sen and qBittorrent tray icons                       |
@@ -32,6 +32,6 @@ Theme and Spectacle need an additional apply step after stowing their package:
 The apply scripts require a running KDE Plasma 6 session. Ngó Sen icons need
 an additional install step described in the tray-icons README.
 
-Packages can be selected independently. Helium includes its generated theme;
+Packages can be selected independently; Helium follows the Darwin Breeze
-it does not require the KDE theme to be installed. Choose either
+colors only when the theme is applied. Choose either `kde/fastfetch` or
-`kde/fastfetch` or `mac/fastfetch`; both own `~/.config/fastfetch/`.
+`mac/fastfetch`; both own `~/.config/fastfetch/`.

kde/helium/.config/helium-browser-flags.conf

@@ -2,5 +2,7 @@
 --ozone-platform-hint=auto
 --enable-features=AcceleratedVideoDecodeLinuxGL,AcceleratedVideoDecodeLinuxZeroCopyGL,AcceleratedVideoEncoder
 
-# Darwin Breeze theme, generated by kde/theme/build.py
+# Don't tag surfaces as sRGB. KWin shows tagged sRGB through a gamma 2.2
---load-extension=~/.local/share/helium-themes/darwinbreeze
+# curve, which lifts dark grays (40 -> 44), so the tab strip would come out
+# lighter than KDE title bars.
+--disable-features=WaylandWpColorManagerV1

kde/helium/.gitignore

@@ -1,2 +0,0 @@
-# Helium caches the built theme next to the manifest.
-Cached Theme.pak

kde/helium/.local/share/helium-themes/darwinbreeze/manifest.json

@@ -1,100 +0,0 @@
-{
-  "manifest_version": 3,
-  "name": "Darwin Breeze",
-  "version": "1.0",
-  "description": "Generated by kde/theme/build.py from DarwinBreezeDark.colors",
-  "theme": {
-    "colors": {
-      "frame": [
-        35,
-        35,
-        35
-      ],
-      "frame_inactive": [
-        35,
-        35,
-        35
-      ],
-      "frame_incognito": [
-        35,
-        35,
-        35
-      ],
-      "frame_incognito_inactive": [
-        35,
-        35,
-        35
-      ],
-      "toolbar": [
-        35,
-        35,
-        35
-      ],
-      "background_tab": [
-        60,
-        60,
-        60
-      ],
-      "background_tab_inactive": [
-        60,
-        60,
-        60
-      ],
-      "tab_text": [
-        223,
-        223,
-        223
-      ],
-      "tab_background_text": [
-        223,
-        223,
-        223
-      ],
-      "tab_background_text_inactive": [
-        155,
-        155,
-        155
-      ],
-      "toolbar_text": [
-        223,
-        223,
-        223
-      ],
-      "toolbar_button_icon": [
-        223,
-        223,
-        223
-      ],
-      "bookmark_text": [
-        223,
-        223,
-        223
-      ],
-      "omnibox_background": [
-        24,
-        24,
-        24
-      ],
-      "omnibox_text": [
-        222,
-        222,
-        222
-      ],
-      "ntp_background": [
-        24,
-        24,
-        24
-      ],
-      "ntp_text": [
-        222,
-        222,
-        222
-      ],
-      "ntp_link": [
-        63,
-        157,
-        255
-      ]
-    }
-  }
-}

kde/helium/README.md

@@ -1,11 +1,14 @@
 # Helium
 
-Browser flags and the generated Darwin Breeze theme. From the repository root:
+Browser flags for hardware video decoding on Wayland and for colors that
+match KDE apps. From the repository root:
 
 ```sh
 stow -d kde -t "$HOME" helium
 ```
 
-The theme files are included, so the KDE `theme` package does not need to be
+Helium takes its colors and window buttons from GTK. In Settings →
-stowed to use Helium's theme. To regenerate its colors from the shared color
+Appearance, set Theme to GTK and turn off "Use system title bar and borders".
-scheme, run `python3 kde/theme/build.py` and restart Helium.
+With the KDE `theme` package applied, GTK follows the Darwin Breeze colors and
+the window buttons match KWin's; see
+[Darwin Breeze → Helium notes](../theme/README.md#helium-notes).

kde/theme/.config/gtk-3.0/chromium.css

@@ -0,0 +1,12 @@
+/* Helium (Chromium) with its GTK theme. Chromium adds a "chromium" class to
+   every node of the GTK style contexts it reads colors from, so these rules
+   reach Helium and no other GTK app.
+
+   In the compact layout, the address bar takes the text field color and the
+   segment with the extension and window buttons takes the window color,
+   which Chromium resolves to the darker view color. Both get the title bar
+   color, so the strip reads as one bar like a KDE title bar. */
+window.background.chromium,
+textview.view.chromium {
+  background-color: @theme_bg_color_breeze;
+}

kde/theme/README.md

@@ -23,11 +23,11 @@ stow -d kde -t "$HOME" theme
 ```
 
 `apply.sh` regenerates the app themes, applies the global theme, hides the
-line under the title bar, turns off the wallpaper accent color and publishes
+line under the title bar, turns off the wallpaper accent color, gives Helium
-the T3 Code theme and installs the VS Code extension. Restart Helium
+the KWin title buttons and an even tab strip, publishes the T3 Code theme and
-afterwards; T3 Code switches on its own. In VS Code, pick "Darwin Breeze Dark"
+installs the VS Code extension. Restart Helium afterwards; T3 Code switches on its own. In VS
-once under Preferences → Color Theme; after later color changes, run Developer:
+Code, pick "Darwin Breeze Dark" once under Preferences → Color Theme; after
-Reload Window.
+later color changes, run Developer: Reload Window.
 
 Telegram has to import its theme by hand: Settings → Chat Settings → Chat
 background → Choose from file, then pick
@@ -49,7 +49,7 @@ Edit it, then run `./kde/theme/apply.sh` again. Everything else follows:
 | Qt / KDE apps                     | the color scheme itself                                                                                                           |
 | GTK apps                          | Breeze GTK, which `kde-gtk-config` syncs from the scheme                                                                          |
 | Tray icons in `kde/tray-icons/`   | `ColorScheme-Text`, recolored by Plasma                                                                                           |
-| Helium                            | `../helium/.local/share/helium-themes/`, generated by `build.py`                                                                  |
+| Helium                            | Breeze GTK, through Helium's GTK theme (see [Helium notes](#helium-notes))                                                        |
 | T3 Code                           | `t3/darwin-breeze.json`, generated by `build.py` and published with `t3 theme set`                                                |
 | VS Code                           | `vscode/package.json` and `vscode/themes/`, generated by `build.py`, packed into `darwin-breeze.vsix` and installed by `apply.sh` |
 | Telegram                          | `telegram/DarwinBreezeDark.tdesktop-theme`, built by `build.py` and imported by hand                                              |
@@ -81,7 +81,7 @@ are built by `build.py` instead. Don't edit generated files by hand.
   are, without gamma compensation, so code looks the same in both apps.
 - The terminal palette is generated from the color scheme.
 - VS Code is Electron, so its workbench colors get the same gamma
-  compensation as Helium and T3 Code.
+  compensation as T3 Code.
 - The `.vsix` isn't committed; `build.py` packs it from `vscode/`.
 
 ## Telegram notes
@@ -94,24 +94,34 @@ are built by `build.py` instead. Don't edit generated files by hand.
   colors, are kept as night has them.
 - The chat list, top bar and compose bar use the window color; the chat
   behind the bubbles and the folder strip use the darker view color.
-- Telegram is a Qt app, so unlike Helium and T3 Code it needs no gamma
+- Telegram is a Qt app, so unlike T3 Code and VS Code it needs no gamma
   compensation.
 - The `.tdesktop-theme` is a zip, so it isn't committed; `build.py` builds it
   from the night palette and the color scheme.
 
 ## Helium notes
 
-- Helium loads the theme from `~/.local/share/helium-themes/darwinbreeze`
+- Helium uses the GTK theme (Settings → Appearance → Theme: GTK) with "Use
-  through `--load-extension` in `kde/helium/.config/helium-browser-flags.conf`.
+  system title bar and borders" off, so the tab strip doubles as the title
-  Install it separately with `stow -d kde -t "$HOME" helium`.
+  bar. Its colors come from Breeze GTK, which `kde-gtk-config` syncs from
-- In Helium's compact layout the active tab and the toolbar segments on either
+  the scheme; there is no Helium theme to generate.
-  side share one theme color, so the toolbar is the same color as the tab
+- With the system title bar off, Helium draws the window buttons through
-  strip and inactive tabs are drawn lighter, as Dolphin does.
+  GTK. `kde-gtk-config` renders the KWin buttons into
+  `~/.config/gtk-3.0/window_decorations.css`, but hands that file to GTK apps
+  through a GTK module that Helium doesn't load, so Helium would show Breeze
+  GTK's own round buttons instead. `apply.sh` imports the file from `gtk.css`
+  so Helium picks it up too.
+- In the compact layout, the address bar takes GTK's text field color and the
+  segment with the extension and window buttons takes the window color, which
+  Chromium resolves to the darker view color. `.config/gtk-3.0/chromium.css`
+  gives both the title bar color, and `apply.sh` imports it from `gtk.css`.
+  Chromium adds a `chromium` class to every GTK node it reads colors from, so
+  the rules reach Helium and no other GTK app.
 - Chromium tags its output as sRGB and KWin shows it with a gamma 2.2 curve,
-  which lifts dark grays (40 becomes 44). `build.py` writes pre-compensated
+  which lifts dark grays (40 becomes 44). T3 Code and VS Code get
-  values for Helium and T3 Code (both Chromium), so the theme files say 35
+  pre-compensated colors from `build.py`; Helium instead runs with
-  where the screen shows 40.
+  `--disable-features=WaylandWpColorManagerV1`, so its surfaces go untagged
-- Under Settings → Appearance the theme must be Classic, not GTK or QT.
+  and show the GTK colors as they are.
 
 ## When the colors don't show up
 

kde/theme/apply.sh

@@ -21,6 +21,21 @@ plasma-apply-lookandfeel --apply dev.trivk.darwinbreeze.dark
 plasma-apply-colorscheme BreezeClassic >/dev/null
 plasma-apply-colorscheme DarwinBreezeDark >/dev/null
 
+# kde-gtk-config writes gtk.css; add our imports to it.
+gtk_import() {
+    local css="${XDG_CONFIG_HOME:-$HOME/.config}/$1/gtk.css"
+    if [ -e "$css" ] && ! grep -qF "'$2'" "$css"; then
+        sed -i "\$a @import '$2';" "$css"
+    fi
+}
+# kde-gtk-config gives GTK apps the KWin title buttons through a GTK module,
+# which Helium doesn't load, so it would fall back to Breeze GTK's own
+# buttons. Importing the same CSS from gtk.css reaches Helium too.
+gtk_import gtk-3.0 window_decorations.css
+gtk_import gtk-4.0 window_decorations.css
+# Helium's tab strip colors (see chromium.css).
+gtk_import gtk-3.0 chromium.css
+
 # Drop the line under the title bar so it blends into the toolbar.
 kwriteconfig6 --file breezerc --group Windeco --key DrawTitleBarSeparator false
 
@@ -45,5 +60,5 @@ fi
 
 echo "Applied Darwin Breeze"
 if pgrep -x helium >/dev/null; then
-    echo "Restart Helium to pick up its theme"
+    echo "Restart Helium to pick up the new colors"
 fi

kde/theme/build.py

@@ -4,7 +4,6 @@
 .local/share/color-schemes/DarwinBreezeDark.colors is the only place colors
 are defined. This script derives from it:
 
-  ../helium/.local/share/helium-themes/darwinbreeze/manifest.json
   t3/darwin-breeze.json   (published to T3 Code by apply.sh)
   telegram/DarwinBreezeDark.tdesktop-theme   (not committed; imported into Telegram by hand)
   vscode/   (packed into vscode/darwin-breeze.vsix, installed by apply.sh)
@@ -24,7 +23,6 @@ from pathlib import Path
 HERE = Path(__file__).resolve().parent
 PKG = HERE
 SCHEME = PKG / ".local/share/color-schemes/DarwinBreezeDark.colors"
-HELIUM = PKG.parent / "helium/.local/share/helium-themes/darwinbreeze"
 T3 = HERE / "t3/darwin-breeze.json"
 # Telegram Desktop's built-in night theme, used as the base for every key the
 # scheme has no role for: the colors file from telegramdesktop/tdesktop at
@@ -54,10 +52,6 @@ CYAN = (100, 210, 255)
 # Apple systemYellow; search highlights in T3 Code.
 YELLOW = (255, 255, 0)
 
-# Breeze draws inactive tabs this far from the window color towards the text
-# color (measured in Dolphin: 40 -> 62 with text 222).
-INACTIVE_TAB_MIX = 0.12
-
 
 def load() -> ColorFn:
     cp = configparser.ConfigParser(interpolation=None, strict=False)
@@ -84,7 +78,8 @@ def kwin_compensate(c: Sequence[int]) -> list[int]:
 
     Chromium tags its surfaces as sRGB, KWin shows them with a gamma 2.2
     curve, so dark grays come out lighter (40 -> 44). Encoding the target
-    with the inverse makes Helium land on the same values as native apps.
+    with the inverse makes Chromium apps land on the same values as native
+    apps.
     """
 
     def ch(v: int) -> int:
@@ -95,40 +90,6 @@ def kwin_compensate(c: Sequence[int]) -> list[int]:
     return [ch(v) for v in c]
 
 
-def helium(color: ColorFn) -> dict[str, list[int]]:
-    bar = color("Header", "BackgroundNormal")
-    text = color("Window", "ForegroundNormal")
-    view = color("View", "BackgroundNormal")
-    view_text = color("View", "ForegroundNormal")
-    inactive_tab = mix(bar, text, INACTIVE_TAB_MIX)
-
-    # In Helium's compact layout the active tab and the toolbar segments on
-    # either side share the toolbar color, so toolbar and frame must match
-    # for the strip to read as one bar. Inactive tabs get the lighter Breeze
-    # tab color, the way Dolphin draws them.
-    colors = {
-        "frame": bar,
-        "frame_inactive": bar,
-        "frame_incognito": bar,
-        "frame_incognito_inactive": bar,
-        "toolbar": bar,
-        "background_tab": inactive_tab,
-        "background_tab_inactive": inactive_tab,
-        "tab_text": text,
-        "tab_background_text": text,
-        "tab_background_text_inactive": color("Window", "ForegroundInactive"),
-        "toolbar_text": text,
-        "toolbar_button_icon": text,
-        "bookmark_text": text,
-        "omnibox_background": view,
-        "omnibox_text": view_text,
-        "ntp_background": view,
-        "ntp_text": view_text,
-        "ntp_link": color("View", "ForegroundLink"),
-    }
-    return {k: kwin_compensate(v) for k, v in colors.items()}
-
-
 def ansi(color: ColorFn) -> list[Color]:
     """The 16 colors for the VS Code terminal."""
     bg = color("View", "BackgroundNormal")
@@ -530,7 +491,7 @@ def vscode(color: ColorFn) -> dict[str, str]:
 
     colors = {k: pins.get(k) or recolor(c) for k, c in base.items()}
     colors.update(pins)
-    # Electron is Chromium, so it needs the same KWin compensation as Helium.
+    # Electron is Chromium, so it needs the KWin compensation.
     return {k: hexc(kwin_compensate(c[:3]) + list(c[3:])) for k, c in sorted(colors.items())}
 
 
@@ -638,17 +599,6 @@ def write(path: Path, data: str | bytes) -> bool:
 
 def main() -> None:
     color = load()
-    manifest = {
-        "manifest_version": 3,
-        "name": "Darwin Breeze",
-        "version": "1.0",
-        "description": f"Generated by kde/theme/build.py from {SCHEME.name}",
-        "theme": {"colors": helium(color)},
-    }
-    if write(HELIUM / "manifest.json", json.dumps(manifest, indent=2) + "\n"):
-        # Helium would keep showing the old colors from its cache.
-        (HELIUM / "Cached Theme.pak").unlink(missing_ok=True)
-
     theme = {"version": 1, "name": "Darwin Breeze", "appearance": "dark", "colors": t3(color)}
     write(T3, json.dumps(theme, indent=2) + "\n")