Animate GIFs in the presentation window#55
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Adds GifAnimationManager (src/renderer/src/lib/gif.ts), a per-canvas manager that decodes GIF data URLs via gifuct-js after the first paint and ticks frames through a scratch-canvas compositor so transparent patches do not erase prior pixels. The editor canvas, GIF backgrounds, and storage stay unchanged. Guardrails: 25 MB encoded size cap, 4096 px logical-dimension cap, 300-frame cap, 2 s post-hoc decode wallclock cap, 64 MB per-canvas memory budget with token-based reservation and reconcile-on-actual. Decode is gated by document.visibilityState; reset()/dispose() cancel schedulers, timers, and refund accounting. Presentation.svelte instantiates one manager next to presentationCanvas, calls reset() at the top of renderSlide(), registers each GIF image after its static frame loads, and start()s playback after image loads settle (including for one-GIF slides). Disposal runs before canvas disposal. The no-slide branch now also clears canvas state and resets the manager so stale visuals/timers do not survive a wipe. Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
Fixes two issues surfaced during QA: 1. The properties panel background preview uses a native <img> tag, so browsers animated the GIF in the editor sidebar even though the canvas GIF stays static. PropertiesPanel.svelte now detects GIF backgrounds and shows the decoded first frame instead, matching the editor canvas. 2. Adds getGifFirstFrameDataUrl(src) in lib/gif.ts — a small async helper that parses the GIF, renders frame 0 through a scratch canvas onto a composite, and returns a PNG data URL. Results are cached by source so repeated previews don't re-decode. Falls back to the original URL on any error so the preview never goes blank. This is a small editor-side affordance; presentation playback is unchanged. (The plan kept App.svelte and presentation behavior fixed; this only touches PropertiesPanel preview rendering and the gif module.) Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
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Summary
GifAnimationManager(src/renderer/src/lib/gif.ts) — a per-canvas manager that decodes GIF data URLs viagifuct-jsafter the first paint and ticks frames through a scratch-canvas compositor so transparent patches do not erase prior pixels.Presentation.svelte: one instance alongsidepresentationCanvas,reset()at the top ofrenderSlide, fire-and-forgetregister()after each static image load,start()after image loads settle (works for one-GIF slides too),dispose()before canvas disposal, and full canvas/state cleanup in the no-slide branch.App.svelteare unchanged.Guardrails (warn-once, fall back to static)
reset()document.visibilityStatepauses scheduling; resumes when visibleTest Plan
npm run typecheck— cleannpm run lint— cleannpm test— 131/131 pass (31 new intests/renderer/lib/gif.test.ts)🤖 Generated with Claude Code