Determine current modal height and/or current position

[Bartosz-L]

Is your feature request related to a problem? Please describe.
Is it possible to determine current modal height? I have modal on top of react-native-maps and on the map itself there are few buttons on the bottom (like geolocation etc). I would like to make them (buttons) jump up along with modal top edge based on the modal current position. Unfortunately I can't find any way to determine its current position.

Describe the solution you'd like
Some callback which gives current height/position of the modal.

Describe alternatives you've considered
Buttons inside the modal but absolutely positioned on top of the modal. But in my case when the modal is closed I would need to render them separately on the map as they need to be visible always.