(left = without smooth, right = smooth; captured by external camera to maximally demonstrate end-user perception. High-resolution video here. Deliberately made it super janky for clear demonstration.)

No matter how heavy the tree is to build/layout, it will run at (roughly) full FPS, feel smooth, has zero uncomfortable janks, with negligible overhead. (Detailed reports here)

Two possibilities:

• Drop-in replacements: For common scenarios, add 6 characters ("Smooth") - ListView becomes SmoothListView, MaterialPageRoute becomes SmoothMaterialPageRoute.

• Arbitrarily flexible builder: For complex cases, use SmoothBuilder(builder: ...) and put whatever you want to be smooth inside the builder.

The documentation - https://fzyzcjy.github.io/flutter_smooth/, with usage, demo, benchmark, insights, and more.

Note Feel free to create an issue if you have any questions/problems. I usually reply quickly within minutes if not hours, except for sleeping :)

Now I am working on pull requests to Flutter framework and engine (i.e. not directly modifying code in this repository), such that you can use this package with standard stable Flutter. An auto-generated list of PRs can be seen here, or conversations here.

Thanks goes to these wonderful people (emoji key following all-contributors specification):

fzyzcjy 💻 📖 🤔

Ian Hickson 🤔

Dan Field 🤔

Jonah Williams 🤔

gaaclarke 🤔

Nayuta403 📖

pajlada 📖

More specifically, thanks for all these contributions:

• @Hixie (Flutter team): Consider details of my several proposals to the Flutter framework/engine such as requiring zero-overhead principle. Construct concrete cases when the initial proposal becomes fragile.
• @dnfield (Flutter team): Provide a canonical janky case inside Flutter framework to help prototyping. Point out slowness of sync generators which avoids detouring.
• @jonahwilliams (Flutter team): Elaborate shortcomings of the old gesture system proposal (later I made a much more natural one).
• @gaaclarke (Flutter team): Share his pet theory that slowness is caused by memory locality, indicating another potential application of the package.
• @Nayuta403: Fix link.
• @pajlada: Fix typo.