Structuring Compose interfaces.
WHAT THE BASIC LAYOUTS ARE
Arranging children vertically Arranging children horizontally Stacking children Lazy lists and grids, for long content
WHAT LAZY MEANS
Only visible items are composed.
WHY THAT MATTERS
Composing thousands of items is slow regardless.
WHAT MODIFIERS DO
Apply behaviour and appearance: size, padding, background, click handling, and much else.
WHAT MATTERS ABOUT THEM
Order. Each modifier wraps the next, so the sequence changes the result.
WHAT THAT LOOKS LIKE
Padding before a background colours a smaller area than padding after.
WHAT TO PROVIDE ON EVERY REUSABLE COMPOSABLE
A modifier parameter, applied first.
WHY
So callers can control layout without the composable deciding for them.
WHAT TO AVOID
Fixed sizes for anything containing text Deeply nested layouts where a single constraint-based one serves Modifiers applied in an order nobody checked
WHAT TO USE FOR KEYS IN LAZY LISTS
A stable identifier from the data.
WHY
Otherwise state attaches to the wrong item when the list changes.
