Module remount 

Changing a widget’s own children in the retained layout tree, in place.

A structure change normally makes the host discard its whole Taffy tree, build every widget’s layout again and solve it from scratch: every text is measured again, though one row came into a list. A widget that only mounts and unmounts children of its own, whose other widgets all stay alive, reports StructureChange::Children instead and carries it out in Widget::remount_children through a Remount: the children it mounts are built into the retained tree, the ones it lets go are removed from it, and every other node keeps its identity and its cached layout. The host admits what was mounted and solves the tree again, which lays out only the nodes the change dirtied.

Structs

Remount

The retained layout tree a Widget::remount_children changes, and what the change mounted and unmounted, for the host to admit.