When starting this project, I've already had experiences with Flutter, so the challenge difficulties will bypass some basic knowledge and the knowledge that I knew it already. 🧑‍💻

1. DraggableScrollableSheet

• Use another sizing widget beside scrolling widget to make sheet affect. Please check demo.
• minChildSize: is for smallest size that sheet can shrink and then opposite is maxChildSize from 0 to 1.
• snap:true: to turn on custom snap, snapSizes: List(double) to define points to snap when users release their finger.

2. ListWheelScrollView

• Use for fancy scrolling
• useMagnifier & magnification: for zoomed-in rate of the magnifier

• SingleChildScrollView is 1 widget, so wrapping another widget with it will cause redundant rebuilds a whole widget tree when scrolling. However, if you have a relatively simple layout and performance isn't a major concern, SingleChildScrollView maybe be more suitable.
• ListView => render a whole list, it doesn't implement lazy loading for UIs.
• ListView.builder => optimize performance better, because of lazy loading UIs (build & render only can-see items). But there is an issue with ListView.builder, it's just able to use for item with the same type.

• Set shrinkWrap: true & physics: const NeverScrollableScrollPhysics() for children list view ? => it will back to ListView mechanism => not good for performance
• Solution: Use Slivers with CustomScrollView.

There are 2 variants: implicit & explicit.

• Implicit rely on simple setting a new value through Widget property, then Flutter takes care the rest.
• Explicit require an animation controller => mean that you need to handle animation manually. Before deciding what type of animation that you need, answering some question first:
• Question list

• The process between old and the new value is called interpolation.
• There are 2 props need to be highlighted.
  1. Duration -> Duration that animation will execute.
  2. Curve -> How transaction works beginning and end values.

• Use case: when can not find any "AnimatedFoo" widget.
• Optimization:
  1. use child parameter is rather than call directly on builder. Because widget will reconstructed every time builder methods get called.
  2. set tween as static final when appropriate.