Gets the child within the Positionable at the given point. The default is to ignore these calls and let the caller perform their own search for the right child. But Layouts are free to return a value here if it can be done more efficiently.

idealSize

open fun idealSize(container: PositionableContainer, default: Size? = null): Size?

Returns the ideal size of the Positionable based on its contents.

minimumSize

open fun minimumSize(container: PositionableContainer, default: Size = Empty): Size

Returns the minimum size of the Positionable based on its contents.

requiresLayout

open fun requiresLayout(container: PositionableContainer, old: Size, new: Size): Boolean

Indicates whether a layout is needed because of the given size change to the Container. This is called whenever the container's size changes.

open fun requiresLayout(child: Positionable, of: PositionableContainer, old: View.SizePreferences, new: View.SizePreferences): Boolean

Indicates whether a layout is needed because of the given size preferences change to a child of the given Container. This is called whenever the container's size changes.

open fun requiresLayout(child: Positionable, of: PositionableContainer, old: Rectangle, new: Rectangle): Boolean

Indicates whether a layout is needed because of the given bounds change to a child of the given Container. This is called whenever the container's size changes.

then

infix fun Layout.then(onLayout: (PositionableContainer) -> Unit): Layout

Provides a way to get notified each time a Layout is done positioning.