Pass a callback from the parent widget all the way down the widget tree to a descendant widget

[eryawanir]

Switching tabs

You have two options to implement switching to the Recipes tab:

1. Standard callback: Pass a callback from the parent widget all the way down the widget tree to a descendant widget. When ready, it fires the callback at each level up the tree and calls setState() to rebuild the Home widget’s subtree.

Give me the example of the code, please