Android 13+ recolors the adaptive icon's `<monochrome>` layer with a
wallpaper-derived tint when the user enables themed icons. Support was added
in #2122/#2153 (the `ic_launcher_monochrome.png` assets) but #2353 ("fixed
launcher icon size") rewrote the committed adaptive icon to inset the
foreground 22% and silently dropped the `<monochrome>` layer, so themed icons
stopped working in shipped builds.
Restore it by re-adding a `<monochrome>` layer (same 22% inset as the
foreground) and shipping the monochrome mipmaps. The CI/release flow
regenerates `gen/android` (`tauri android init` + `tauri icon`) then
`git checkout .` to restore tracked customizations; `tauri icon` does not emit
a monochrome layer, so the mipmaps are force-committed under `gen/` like the
other customized resources.
The monochrome artwork is redesigned: Android tints the layer via SRC_IN
(alpha only), which flattened the old desaturated-logo asset into a solid
blob. A narrow vertical center gap now splits the open book into two pages
with a visible spine while keeping the bookmark, so the mark keeps its
character when themed.
Verified on a Pixel 9 Pro emulator (Android 36) with Themed Icons enabled, and
guarded by src/__tests__/android/themed-icon.test.ts.
Co-authored-by: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Huang Xin
664b6125a2