Rendering gallery

The Player bundles the example gallery of its rendering engine — modernc.org/webview, the pure-Go HTML / CSS / JavaScript engine behind the WebView widget. It is a curated showcase of what the engine renders, from CSS Level 1 through CSS 3, HTML 5, international text, and live JavaScript — all from content bundled inside the Player, with no network access.

In-app link. In the Player's built-in docs viewer (scriptweaver --help), this opens directly in the app. There is nothing to open on the web.

What it shows

CSS — the box model, flexbox, CSS Grid, 2-D transforms, opacity and filters (blur, grayscale, sepia, hue-rotate …), transitions and @keyframes animations, custom properties, calc(), sticky positioning, and @font-face web fonts.
Tables & layout — border-collapse, table-layout, floats, relative / absolute / fixed positioning with z-index stacking, and nested overflow scrollers.
HTML 5 — semantic elements, form input types, <progress> / <meter> gauges, inline SVG, and WebP images.
International text — bidirectional Arabic / Hebrew and CJK line breaking, with per-run script shaping and system-font fallback.
JavaScript — a live clock (timers), DOM building and mutation, events, fetch over the local loader, ES modules, and the browser object model — each page interactive, running on the Player's own QuickJS.

How it works

The gallery opens in a WebView in navigation mode: link clicks browse between pages, the ◀ / ▶ / ⌂ toolbar walks history, and the JavaScript pages are live. It is a genuine mini-browser — but only over the bundled gallery: a navigation allowlist pins it to the gallery's own pages, so it never reaches the network.

This is the same widget your app gets from app.WebView(...). To build your own gallery-style viewer, point one at the bundled gallery:

const wv = app.WebView({ navigate: sw.app.galleryBase, script: true });
wv.pack.configure({ fill: 'both', expand: true });
wv.loadUrl(sw.app.galleryBase + '/index.html');

See the WebView reference for the full API — navigation mode ({navigate: …}, back() / forward(), onNavigate), scripting, and sw.app.galleryBase.

Checking your own pages

The gallery shows what the engine does render. For the other half of the question — what happens to a page you wrote — the Player's repository ships pageview, a small viewer that opens your HTML in this same engine:

scriptweaver apps/pageview/main.js path/to/page.html

It reloads the page as you edit it, emulates narrower viewports so @media breakpoints fire, and — reading the source back — names the constructs the page asked for that the engine does not implement. That last part is the point: the engine fails silently, so an <iframe> or a <canvas> renders nothing at all rather than an error. A browser cannot tell you this, because it renders them. See apps/pageview/README.md in the repository for the full description.