Make custom callout views easier to use [WIP]

[friedbunny]

Following on from #4392, this pull request aims to simplify custom callout view creation and usage.

Changes

MGLCalloutView protocol

• Simplified.
• Most properties are optional, including accessory views and title strings.
• Adds -detailAccessoryView.

MGLCalloutViewDelegate

• Removed.

MGLAnnotation (Really, only MGLPointAnnotation)

• Adds -canShowCallout boolean property.
• Adds -calloutView property that conforms to MGLCalloutView protocol.

MGLCompactCalloutView

• Replaced SMCalloutView with custom implementation.
  • Current placeholder is based on the existing custom callout view example:

Todo

• Interface Builder support.
• Accessibility.
• Hook-up accessory views.
• Handle gestures for callouts.
  • Re-enable -[MGLMapView mapView:annotation:calloutAccessoryControlTapped:].
  • Add custom gesture handlers to custom callout example.
• Fit the default callout view to the viewport.
• Add MGLCalloutView.annotation?
  • Instead of manually re-setting the title and subtitle properties, maybe let the callout implementation do that directly with a passed-in annotation.
• Audit MGLMapView for dead delegate methods; remove or deprecate.
  • -mapView:annotationCanShowCallout:
  • -mapView:calloutViewForAnnotation:
  • -mapView:tapOnCalloutForAnnotation:
  • -mapView:rightCalloutAccessoryViewForAnnotation:
  • -mapView:leftCalloutAccessoryViewForAnnotation:

Stretch goals

• Make the default callout view swanky.
  • Animations and other polish.
• Eliminate need for public MGLCalloutView protocol.
• Enable callout views for MGLMultiPoint (polylines, polygons) Punted per Make custom callout views easier to use [WIP] #4948 (comment).
• Allow callout views to remain open while panning.

/cc @1ec5 @boundsj

[friedbunny]

This is still a big work-in-progress; b6c0c9f is my stopping point for tonight.

My approach so far has been to go through with a machete, showing wanton disregard for backwards compatibility, but clearly we’ll have to address deprecation one way or another before this is ready to go.

[friedbunny]

This is slated for removal.

[friedbunny]

Pushing this off of v3.3.0 — haven’t made enough progress and there’s a lot of other validation to do for that release. I may keep picking at this in the meantime, though.

[andrewstay]

Please clarify if that means I have to allocate all the callout views for all the annotations on the map and keep those views in the memory even though user may never click on those?

[1ec5]

@andrewstay, by the time this feature lands, it’ll work similarly to annotation views. Callout views will go into a reuse queue, so the number of allocated views will be limited.

[friedbunny]

This has been rebased onto the current master — will be picking up work on this again this week.

[friedbunny]

So stale. Hopefully this will happen eventually!