A VS Code extension that previews BUSY Bar .anim animation in a player.
Open any .anim file and it plays automatically.
Features
Custom editor for *.anim (default for the extension), read-only, themed
with VS Code colors.
Plays the animation looped in its native frame rate. Pauses when the tab is hidden.
Both container revisions: bicycle1 (masked interframe frames, raw / RLE /
QOI-like pixels, 3 color formats) and the legacy bicycle0 (full frames with
per-frame durations).
Sections: play the whole file or a specific anim section.
Keyboard: Space play/pause, ←/→ step, Home restart, +/- zoom.
Live reload: rebuilding the .anim on disk refreshes the open preview.
Commands: BUSY Bar Anim: Open Animation Preview (also in the explorer and
editor title context menus for .anim files) and
BUSY Bar Anim: Show Animation Info, which opens a Markdown report of the
header, sections and warnings.
Settings
Setting
Default
Description
busybarAnim.autoplay
true
Start playing on open. Ignored when the system asks for reduced motion.
busybarAnim.background
checkerboard
Background behind frames with transparency.
Development
npm install
npm run build # bundle the extension, webview and decoder into dist/ and media/
Then press F5 (Run Extension) and open any .anim file.
Scripts
Script
Purpose
npm run build
Minified production bundles (dist/extension.js, media/preview.js, …)
npm run compile
Fast development bundles with source maps
npm run watch
Rebuild on change (used by the F5 launch configuration)
npm run typecheck
tsc --noEmit
npm test
Builds, then runs decoder + extension host tests
npm run harness
Generates test/harness/preview.html, a browser page that runs the webview imitating VS Code
npm run render -- <file.anim> <out.png>
Decodes to PNG for eyeballing; --frame n for a single frame, --scale, --columns, --file-frames
The browser harness is useful for UI work (no Extension Host needed):
npm run harness
npx http-server . -p 8777
# open http://127.0.0.1:8777/test/harness/preview.html
