Chat list / scroll view wishlist for iOS

I want a chat-style list view with strong built-in scrolling behavior, not just message rendering.

Core layout

• The list should be bottom-anchored
• New messages should appear from the bottom and stack upward
• This should work both when content is taller than the viewport and when content is shorter than the viewport

Insert animation behavior

• When a new message arrives, it should visibly animate upward into place
• Even if the content is smaller than the scroll view, a new message should still push previous content upward in a natural way
• No abrupt popping in

Auto-scroll behavior

• If the user is already at, or near, the bottom, a new message should animate the list to the bottom
• If the user has scrolled up reading older messages, a new message should not yank them back down
• There should be a configurable threshold for this near-the-bottom behavior

Scroll preservation

• When loading more content, such as older messages fetched from a server, the scroll position should remain visually stable
• The user should be able to keep scrolling without jumps, glitches, or content shifting unexpectedly
• This should work well with long lists and incremental loading

Programmatic scrolling

I want APIs for: