If you're wondering how navigation drawers work with gestural navigation, it looks like this. 👇
Apps need to update to DrawerLayout 1.1.0-alpha01 (out this week). You can try this yourself in the #io19 Android app in Q Beta 3
The one downside I saw in the I/O app was if you were a couple screens in, opened the drawer, and then swiped back. The underlying content would go back, but it was really hard to see if anything changed because the drawer was still open.
That whole paradigm is just weird an unintuitive IMO. I really like how Vivid NG does it (been using it for a few months). Basically, only the bottom of the screen is captured so you get normal interactions with a bit of finger stretch.
It would be nice to have swipe to go back and drawer at the same time but it's a bit weird too. Should ot wait until drawer closes and then go back or go back and close the drawer at the same time? I think that's why drawers were not so popular on iOS. 1/2
I saw 2 patterns on iOS:
1. Swipe always goes back and drawer can be opened only by tapping on a burger icon.
2. Swipe always opens drawer and to go back you have to tap back button on the toolbar. 2/2
And you have to be careful when designing the app. You can't have full width scrollable views in the bottom area of the screen, right? So carousels or scrollable bottom navbars have to be padded left/right.