User dot callout view dismisses when user location changes slightly

[1ec5]

On iOS, the user dot's callout view is automatically dismissed whenever the user location changes. It should not be dismissed when the location change is small, because that's usually just the result of Core Location refining its location.

/cc @friedbunny

[1ec5]

Keeping the callout view open in this case does not expose any view syncing performance issues, because the user dot itself isn't animated (see #1582).

[friedbunny]

Sounds good to me. We show the accuracy pulse (haloLayer) when location accuracy is <10 meters, but I'm thinking an additional screen distance threshold may be better for the callout — unless potentially jumping all the way across the screen doesn't look that bad.

[incanus]

We should just ensure that the dot isn't in fact moving perceptibly, since we can't yet reposition callouts (or other views) synced to the map yet (#1125).

[1ec5]

@incanus, I don't think that's a problem in this case: #2618 (comment).

[incanus]

Right, so I guess we use -[MGLMapView metersPerPixelAtLatitude:] combined with changes of < 1 pixel.

[friedbunny]

Is this adequately addressed by your recent changes in #3589, @1ec5?

[1ec5]

No, not until #1582 lands.

[1ec5]

I stand corrected: even though the user dot and its callout don’t animate around yet outside of user tracking mode, the callout view does stay open. Closing.