Displays a scrollable list of items lazily fetched from an asynchronous data source. Async list view is a thin wrapper on top of ListView.builder and StreamSummaryBuilder.

Because items are only fetched when they're visible to the user, async list view reduces potentially expensive database reads.

Example use cases:

• display user chat history retrieved from Firestore.
• display search results for items on an online marketplace.
• display log lines read from a large file.

Any contributions, bug reports, or feature requests are welcome.