Do adding, removing a child to stack cause all stack children to rebuild?

Question

Let's say I have a stack of 100 positioned widget children, I add one new positioned widget to that stack but the rest don't change, then I setState to rebuild that stack, should all 100 children run their rebuild function? I ask because this is happening in my app but was hoping I could prevent the rebuild of the entire stack, since flutter should see most of the stack as unchanged.

edit: [more accurately, how do i make sure i'm not re-rendering all 100 widgets in the stack when i add one child or remove one child, is there a way to verify, inspect the render tree]

is there a way to isolate the 100 by wrapping them somehow, or other solution — Aaron Halvorsen
btw what are those 100 widgets? are they typical widgets like buttons, text fields, sliders etc or you are trying to use some widgets in a hacky way? — pskink
they're draggable widgets that can be moved around the screen that have a variety of widget trees with text , images, CustomPainter paths. — Aaron Halvorsen
they have positions so they can stay in that position after dragging. as you can imagine i don't want all of them to refresh if i just add one or remove one. — Aaron Halvorsen

Husen Husen · Accepted Answer · 2021-02-03T19:21:11

All the widgets inside a stateful widget should be rebuild in every setState, To prevent of setState some widgets you should have a separate stateful widget for the stack. this may useful

Do adding, removing a child to stack cause all stack children to rebuild?

1 Answers