Lottie for Flutter

Purpose

This skill provides exhaustive, source-grounded operating instructions for an autonomous AI coding agent implementing, refactoring, optimizing, and reviewing Lottie animations within Flutter applications. It codifies the architecture of the pure Dart lottie runtime (lottie: ^3.5.1), establishes strict composition lifecycle and resource ownership models, enforces multi-platform rendering efficiency across Impeller and CanvasKit/Wasm, and prevents performance, memory, and ticker leaks.

When to Use This Skill

Activate this skill whenever a task involves:

• Adding, updating, or styling Lottie animations in Flutter.
• Integrating AnimationController with Lottie compositions, progress scrubbing, or marker-based playback.
• Dynamically altering animation colors, strokes, opacity, text, or paths via ValueDelegate and LottieDelegates.
• Loading animations from assets, network URLs, files, memory bytes, .zip bundles, .tgs (Telegram stickers), or .lottie (dotLottie) containers.
• Optimizing frame rates, repaint boundaries, CPU/GPU overhead, and memory consumption in animated UIs.
• Embedding animations inside virtualized scroll views (ListView, GridView, CustomScrollView).
• Designing reusable, accessible, and theme-adaptive design system animation components.
• Diagnosing jank, raster thread delays, unhandled composition exceptions, or memory leaks.