Allow locationFor(styleManager:) to optionally return location

CHANGELOG.md

@@ -1,5 +1,9 @@
 # Changes to the Mapbox Navigation SDK for iOS
 
+## master
+
+* `StyleManager.locationFor(styleManager:)` now allows for an optional CLLocation to be returned. [#1523](https://github.com/mapbox/mapbox-navigation-ios/pull/1523)
+
 ## v0.18.1 (June 19, 2018)
 
 ### Packaging

MapboxNavigation/NavigationViewController.swift

@@ -608,16 +608,14 @@ extension NavigationViewController: TunnelIntersectionManagerDelegate {
 
 extension NavigationViewController: StyleManagerDelegate {
 
-    public func locationFor(styleManager: StyleManager) -> CLLocation {
-        guard let location = routeController.location else {
-            if let coordinate = routeController.routeProgress.route.coordinates?.first {
-                return CLLocation(latitude: coordinate.latitude, longitude: coordinate.longitude)
-            } else {
-                return CLLocation()
-            }
+    public func locationFor(styleManager: StyleManager) -> CLLocation? {
+        if let location = routeController.location {
+            return location
+        } else if let firstCoord = routeController.routeProgress.route.coordinates?.first {
+            return CLLocation(latitude: firstCoord.latitude, longitude: firstCoord.longitude)
+        } else {
+            return nil
         }
-
-        return location
     }
 
     public func styleManager(_ styleManager: StyleManager, didApply style: Style) {

MapboxNavigation/StyleManager.swift

@@ -9,7 +9,7 @@ public protocol StyleManagerDelegate: NSObjectProtocol {
     /**
      Asks the delegate for a location to use when calculating sunset and sunrise.
      */
-    @objc func locationFor(styleManager: StyleManager) -> CLLocation
+    @objc func locationFor(styleManager: StyleManager) -> CLLocation?
 
     /**
      Informs the delegate that a style was applied.

MapboxNavigationTests/NavigationViewControllerTests.swift

@@ -210,7 +210,7 @@ class NavigationViewControllerTests: XCTestCase {
 }
 
 extension NavigationViewControllerTests: NavigationViewControllerDelegate, StyleManagerDelegate {
-    func locationFor(styleManager: StyleManager) -> CLLocation {
+    func locationFor(styleManager: StyleManager) -> CLLocation? {
         return dependencies.poi.first!
     }
 

MapboxNavigationTests/StyleManagerTests.swift

@@ -79,7 +79,7 @@ extension StyleManagerTests: StyleManagerDelegate {
     func styleManagerDidRefreshAppearance(_ styleManager: StyleManager) { }
     func styleManager(_ styleManager: StyleManager, didApply style: Style) { }
 
-    func locationFor(styleManager: StyleManager) -> CLLocation {
+    func locationFor(styleManager: StyleManager) -> CLLocation? {
         return location
     }
 }