The weather widget's icons/layout are hand-drawn PIL primitives -- clean
under quantization but flat, no gradients/shadows. Adds an opt-in
render_style="modern" (current/daily modes only) that instead renders a
Jinja2 template through a persistent headless-Chromium browser
(app/html_render.py), following the approach of Tesserae, an open-source
e-ink dashboard targeting this same panel family.
Key design points:
- The Chromium dependency (Playwright) is lazily imported only when a
weather widget actually uses "modern" style, and the background browser
itself only launches on first use -- every other widget type, and this
one's own classic/hourly/multi_city paths, never pay for it.
- No Frame-level dithering setting needed: html_render dithers its own
rendered widget to exact palette colors (Bayer/ordered, not
Floyd-Steinberg) before compositing, so the shared whole-canvas
Floyd-Steinberg pass sees zero quantization error there and leaves it
untouched -- same trick draw_text/hand-drawn icons already use. Floyd-
Steinberg keeps working unchanged for photos and every other widget.
- A "Load calibrated Spectra 6 preset" button in Advanced configuration
offers a community-measured palette (data ported from
paperlesspaper/epdoptimize, Apache 2.0) as an alternative starting
point to the existing idealized DEFAULT_PALETTE_RGB -- fills the
existing palette table, doesn't save by itself.
Known open risk, not resolved here: a headless Chromium binary is far
larger than the ~100MB single-layer limit that already forced this
project's pip/npm installs into split layers, and (unlike those) is a
single ~180MB file that can't be split across layers by ordinary
Dockerfile restructuring. Flagged prominently in server/Dockerfile and
docs/widgets.md -- treat this render style as experimental/local-only
until that's resolved.
