State Machine Visualizer
Visual debugging tool for state machines in Flutter applications.
Why I Built This
Tech Stack
Technical Approach
Built a DevTools extension that intercepts state machine events and renders them as an interactive graph.
Event Interception
Created hooks to capture state transitions from popular state management libraries.
Graph Rendering
Built a force-directed graph layout using CustomPainter for smooth performance.
Time Travel
Implemented state history tracking with ability to replay transitions.
DevTools Integration
Packaged as a Flutter DevTools extension for seamless workflow integration.
Key Learnings
What worked, what didn't, and what I'd do differently.
What Worked
- Force-directed layout creates intuitive state visualization
- Color-coded transitions help identify patterns quickly
- Zoom and pan make large state machines navigable
Challenges Faced
- Initial canvas rendering was too slow for complex graphs
- DevTools API had undocumented quirks that required workarounds
Key Insights
The bigger lessons that go beyond this specific experiment.
Visual Debugging Helps
Seeing state flow visually catches issues that console logs miss.
DevTools Extension API
The API is powerful but documentation is sparse — source code reading is essential.
Performance Critical
Debug tools must be fast or developers won't use them.