SetViewpointCenterAsync isn't actually in the center only on iOS

Question

The method SetViewpointCenterAsync doesn't actually set the view point to the center of the control on iOS but slightly above it. This does not happen on Android. You can easily see this, if you have an active location source displayed and use this to center like this: MapView.SetViewpointCenterAsync(MapView.LocationDisplay.Location.Position); The first screenshot includes a cursor image, where the correct center should be using a Xamarin AbsoluteLayout like this: My guess is, that the MapView somehow included the screen dead zone / area insets in it's center point calculation. I haven't found any property to disable this though. Esri ArcGIS Runtime version 100.12.0. Screenshots taken on iPhone X.

MatthiasPorges · Answer

If it's by design, it should behave the same on Android devices with safe areas (at least on Xamarin Forms). There should also be a proper way to disable/adjust this that doesn't involve creating a negative value ViewInset with a self-calculated value.

Please consider changing this in the future.

SomeGISGuy · Answer

Yes you are right - I should have caught that earlier. It is indeed taking the safe area into account on iOS (this is by design / on purpose btw)

MatthiasPorges · Answer

I did some further testing, and it seems the MapView controls thinks the center is exactly 48 pixel off. I can "fix" this issue by actually adding a negative ViewInsets.Top value:

MapView.ViewInsets = new Thickness(0, -48, 0, 0);

48 pixel happens  to be exactly the height of the top safe area inset (aka the "notch") of the iPhone 11 simulator I'm testing on.

So this seems to further my suspicion: The control might somehow have a "hidden" Viewinset that takes the iPhones notch into account for the center calculation. I have to test this on multiple devices though to make sure.

I think this is a bug in the ArcGis runtime on iOS, because this does NOT happen on Android devices with a notch.