In `Nav3`, how do I block back press while in some...

# compose

[ursus]

In Nav3, how do I block back press while in some state (state.isProcessing == true) in the screen?

[Winson Chiu]

It's the same as Nav2, use BackHandler or the new NavigationEventHandler.

[Winson Chiu]

You could also manually block it by preventing changes to the backstack, since you fully control the list now.

[ursus]

well, then root composable containing navdisplay would need to know aby the child's processing, which can be tricky I guess

but okay `BackHandler`thanks!