canPop property
final
When false, blocks the current route from being popped.
This includes the root route, where upon popping, the Flutter app would exit.
If multiple PopScope widgets appear in a route's widget subtree, then
each and every canPop must be true in order for the route to be
able to pop.
Android's predictive back feature will not animate when this boolean is false.
Implementation
final bool canPop;