Map view should not force its tint color onto subviews

[friedbunny]

Platform: iOS v3.6.0

Since forever, we’ve been forcefully updating MGLMapView’s subviews to match its tint color. @boundsj’s post in #8522 (comment) contains a great explanation of why and how we’ve done this.

The problem is, it’s not necessary for MGLMapView to handle updating its subviews — UIKit will automatically inform subviews via -tintColorDidChange, where that subview can decide for itself whether or not to update with its parent view.

Proposal

• Get rid of -[MGLMapView tintColorDidChange] entirely.
• Implement -tintColorDidChange in custom subviews that we want to keep in sync with the map view’s tint — mainly MGLFaux3DUserLocationAnnotationView, perhaps MGLCompactCalloutView.
• Recommend that developers do the same.

This would be a potentially breaking change for developers who are relying on not having to implement -tintColorDidChange themselves, so I’ve tentatively put it on the v3.7.0 milestone.

Example

1. Set the attribution button’s tint color to a novel color.
2. Present an alert view controller, which dims the map view tint color.
3. Dismiss the alert view controller.

Current result: The attribution button’s custom tint color is lost, as MGLMapView recursively resets its subviews’ tint colors to match itself, triggered by -tintColorDidChange.

Fixed result: The attribution button’s custom tint color is kept, because it no longer inherits its tint from MGLMapView and we’re not forcing it to change.

/cc @1ec5 @boundsj @fabian-guerra @jmkiley

[friedbunny]

The attribution button has been opted-out of MGLMapView’s tint updating (#9598), starting in v3.6.1.

[boundsj]

Fixed in #9598

[friedbunny]

#9598 did this for the attribution button, but I think we should do the same for any subview of the map view.

[stale]

This issue has been automatically detected as stale because it has not had recent activity and will be archived. Thank you for your contributions.

[stale]

This issue has been automatically detected as stale because it has not had recent activity and will be archived. Thank you for your contributions.

[gobetti]

Hey team, sorry for summoning this back but, this is actually causing our whole callout (and subviews) tintColor to be replaced, and looking at the -[MGLMapView updateTintColorForView:] loop I'm not seeing a way around it.

Do you still have plans to remove that? 🙏

Thank you!