_ResizingBox

extends

StatefulWidget

_ResizingBox

this

child1

this

child2

);

final

Widget

child1

final

Widget

child2

@override

State

StatefulWidget

createState

()

_ResizingBoxState

();

class

_ResizingBoxState

extends

State

_ResizingBox

with

SingleTickerProviderStateMixin

Animation

animation

@override

void

initState

()

super