ExpandableView

@Composable

fun WindowContainerConstraintsScope.ExpandableView(modifier: Modifier = Modifier, state: ExpandableViewState = rememberExpandableViewState(), mainContent: @Composable (state: ExpandableViewState) -> Unit, expandedPanel: @Composable (state: ExpandableViewState) -> Unit)

A ready-to-use expandable window container component.

Behavior:

mainContent is always laid out.
expandedPanel is only laid out when ExpandableViewState.isExpanded is true.
The expansion/collapse motion is driven externally by animating the physical window size via SpatialContainerUtils.resizeCurrentWindowContainer; this composable does NOT add any internal enter/exit animation.
On every measure pass (including ones triggered by the user dragging the window), the expanded panel is measured first with its fixed width (clamped to the available width), and whatever width remains is given to mainContent. The panel height always matches the full container height.

modifier

The modifier to be applied to the container.

state

The ExpandableViewState that controls expansion and drives the external resize animation.

mainContent

The primary composable content that is always visible.

expandedPanel

The composable content to display alongside the main content when expanded.