Add visible annotations to the map at intersecting roads along the active route as well as at maneuver points.

Author: avi-c

Example/ViewController.swift

@@ -453,6 +453,7 @@ class ViewController: UIViewController {
     func present(_ navigationViewController: NavigationViewController, completion: CompletionHandler? = nil) {
         navigationViewController.modalPresentationStyle = .fullScreen
         activeNavigationViewController = navigationViewController
+        activeNavigationViewController?.navigationMapView?.showIntersectionAnnotations = true
 
         present(navigationViewController, animated: true) {
             completion?()
@@ -467,6 +468,7 @@ class ViewController: UIViewController {
 
     func dismissActiveNavigationViewController() {
         activeNavigationViewController?.dismiss(animated: true) {
+            self.activeNavigationViewController?.navigationMapView?.showIntersectionAnnotations = false
             self.activeNavigationViewController = nil
         }
     }

MapboxNavigation.xcodeproj/project.pbxproj

@@ -395,6 +395,10 @@
 		DAD903AF23E3DCC80057CF1F /* DateTests.swift in Sources */ = {isa = PBXBuildFile; fileRef = DAD903AE23E3DCC80057CF1F /* DateTests.swift */; };
 		DADD82802161EC0300B8B47D /* UIViewAnimationOptionsTests.swift in Sources */ = {isa = PBXBuildFile; fileRef = DADD827F2161EC0300B8B47D /* UIViewAnimationOptionsTests.swift */; };
 		DAFA92071F01735000A7FB09 /* DistanceFormatter.swift in Sources */ = {isa = PBXBuildFile; fileRef = 351BEC0B1E5BCC72006FE110 /* DistanceFormatter.swift */; };
+		F43EE329261F98DC0039D56F /* NavigationMapView+RoadAnnotations.swift in Sources */ = {isa = PBXBuildFile; fileRef = F43EE328261F98DC0039D56F /* NavigationMapView+RoadAnnotations.swift */; };
+		F43EE32A261F98DC0039D56F /* NavigationMapView+RoadAnnotations.swift in Sources */ = {isa = PBXBuildFile; fileRef = F43EE328261F98DC0039D56F /* NavigationMapView+RoadAnnotations.swift */; };
+		F488A0BE26261C4600A4CC8C /* NavigationMapView+IntersectionAnnotations.swift in Sources */ = {isa = PBXBuildFile; fileRef = F488A0BD26261C4600A4CC8C /* NavigationMapView+IntersectionAnnotations.swift */; };
+		F488A0C826261D8100A4CC8C /* ElectronicHorizon.swift in Sources */ = {isa = PBXBuildFile; fileRef = F488A0C726261D8100A4CC8C /* ElectronicHorizon.swift */; };
 		F4BF512E24EAD7A50066A49B /* FeedbackSubtypeCollectionViewCell.swift in Sources */ = {isa = PBXBuildFile; fileRef = F4BF512D24EAD7A50066A49B /* FeedbackSubtypeCollectionViewCell.swift */; };
 		F4C5A26F24EF1D16004ED0DD /* FeedbackSubtypeViewController.swift in Sources */ = {isa = PBXBuildFile; fileRef = F4C5A26E24EF1D16004ED0DD /* FeedbackSubtypeViewController.swift */; };
 /* End PBXBuildFile section */
@@ -1021,6 +1025,9 @@
 		DAFEB36D2093A11F00A86A83 /* ko */ = {isa = PBXFileReference; lastKnownFileType = text.plist.strings; name = ko; path = ko.lproj/Localizable.strings; sourceTree = "<group>"; };
 		DAFEB36E2093A3E000A86A83 /* ko */ = {isa = PBXFileReference; lastKnownFileType = text.plist.strings; name = ko; path = ko.lproj/Localizable.strings; sourceTree = "<group>"; };
 		DAFEB36F2093A3EF00A86A83 /* ko */ = {isa = PBXFileReference; lastKnownFileType = text.plist.stringsdict; name = ko; path = Resources/ko.lproj/Localizable.stringsdict; sourceTree = "<group>"; };
+		F43EE328261F98DC0039D56F /* NavigationMapView+RoadAnnotations.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = "NavigationMapView+RoadAnnotations.swift"; sourceTree = "<group>"; };
+		F488A0BD26261C4600A4CC8C /* NavigationMapView+IntersectionAnnotations.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = "NavigationMapView+IntersectionAnnotations.swift"; sourceTree = "<group>"; };
+		F488A0C726261D8100A4CC8C /* ElectronicHorizon.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = ElectronicHorizon.swift; sourceTree = "<group>"; };
 		F4BF512D24EAD7A50066A49B /* FeedbackSubtypeCollectionViewCell.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = FeedbackSubtypeCollectionViewCell.swift; sourceTree = "<group>"; };
 		F4C5A26E24EF1D16004ED0DD /* FeedbackSubtypeViewController.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = FeedbackSubtypeViewController.swift; sourceTree = "<group>"; };
 /* End PBXFileReference section */
@@ -1352,6 +1359,7 @@
 				35002D721E5F6C830090E733 /* Supporting files */,
 				AED6285522CBE4CE00058A51 /* ViewController+GuidanceCards.swift */,
 				8A092F9A25DEE81900CA7CF5 /* ViewController+FreeDrive.swift */,
+				F43EE328261F98DC0039D56F /* NavigationMapView+RoadAnnotations.swift */,
 				3577B877214FF35800094294 /* FavoritesList.swift */,
 				358D14651E5E3B7700ADE590 /* AppDelegate.swift */,
 				35379CFB21480BFB00FD402E /* AppDelegate+CarPlay.swift */,
@@ -1658,6 +1666,8 @@
 				8AE9081125FAA53300F37077 /* Collection.swift */,
 				8A8C3D97260175D20071D274 /* CLLocationDirection.swift */,
 				8A446644260A7B24008BA55E /* BoundingBox.swift */,
+				F488A0BD26261C4600A4CC8C /* NavigationMapView+IntersectionAnnotations.swift */,
+				F488A0C726261D8100A4CC8C /* ElectronicHorizon.swift */,
 			);
 			name = Extensions;
 			sourceTree = "<group>";
@@ -2555,6 +2565,7 @@
 				8DEDEF3421E3FBE80049E114 /* NavigationViewControllerDelegate.swift in Sources */,
 				8A446645260A7B24008BA55E /* BoundingBox.swift in Sources */,
 				8AD866F625CA1BF10019A638 /* NavigationCamera.swift in Sources */,
+				F488A0C826261D8100A4CC8C /* ElectronicHorizon.swift in Sources */,
 				8D5DFFF1207C04840093765A /* NSAttributedString.swift in Sources */,
 				35CF34B11F0A733200C2692E /* UIFont.swift in Sources */,
 				8AD866F925CA1BF10019A638 /* ViewportDataSource.swift in Sources */,
@@ -2579,6 +2590,7 @@
 				160D8279205996DA00D278D6 /* DataCache.swift in Sources */,
 				8AFF437125F847340053CBB1 /* CameraOptions.swift in Sources */,
 				351BEBF21E5BCC63006FE110 /* Style.swift in Sources */,
+				F488A0BE26261C4600A4CC8C /* NavigationMapView+IntersectionAnnotations.swift in Sources */,
 				43FB386923A202420064481E /* Route.swift in Sources */,
 				3EA937B1F4DF73EB004BA6BE /* InstructionPresenter.swift in Sources */,
 				5A1C075824BDEB44000A6330 /* PassiveLocationManager.swift in Sources */,
@@ -2600,6 +2612,7 @@
 			buildActionMask = 2147483647;
 			files = (
 				358D14681E5E3B7700ADE590 /* ViewController.swift in Sources */,
+				F43EE329261F98DC0039D56F /* NavigationMapView+RoadAnnotations.swift in Sources */,
 				C5D9800D1EFA8BA9006DBF2E /* CustomViewController.swift in Sources */,
 				AED6285622CBE4CE00058A51 /* ViewController+GuidanceCards.swift in Sources */,
 				8A092F9B25DEE81900CA7CF5 /* ViewController+FreeDrive.swift in Sources */,
@@ -2705,6 +2718,7 @@
 				C53F2EE720EBC95600D9798F /* WaypointConfirmationViewController.swift in Sources */,
 				C5DE4B6220F6B6B3007AFBE6 /* CustomStyles.swift in Sources */,
 				8A0D5DB725DF2A86006F0919 /* StyledFeature.swift in Sources */,
+				F43EE32A261F98DC0039D56F /* NavigationMapView+RoadAnnotations.swift in Sources */,
 				DA8805002316EAED00B54D87 /* ViewController+GuidanceCards.swift in Sources */,
 				8A092F9C25DEE81900CA7CF5 /* ViewController+FreeDrive.swift in Sources */,
 				35379CFD21480C0500FD402E /* AppDelegate+CarPlay.swift in Sources */,

NavigationMapView+RoadAnnotations.swift

@@ -0,0 +1,12 @@
+import UIKit
+import Turf
+import MapboxDirections
+import MapboxCoreNavigation
+import MapboxNavigation
+import MapboxCoreMaps
+import MapboxMaps
+
+// MARK: - Visible annotations on the map about the current drive
+
+extension NavigationMapView {
+}

Sources/MapboxCoreNavigation/CoreConstants.swift

@@ -363,6 +363,8 @@ extension ElectronicHorizon {
         /**
          A key in the user info dictionary of a `Notification.Name.electronicHorizonDidEnterRoadObject` or `Notification.Name.electronicHorizonDidExitRoadObject` notification. The corresponding value is a `RoadObjectIdentifier` identifying the road object that the user entered or exited. */
         public static let roadObjectIdentifierKey: NotificationUserInfoKey = .init(rawValue: "roadObjectIdentifier")
+
+        public static let roadGraphIdentifierKey: NotificationUserInfoKey = .init(rawValue: "roadGraph")
 
         /**
          A key in the user info dictionary of a `Notification.Name.electronicHorizonDidEnterRoadObject` or `Notification.Name.electronicHorizonDidExitRoadObject` notification. The corresponding value is an `NSNumber` containing a Boolean value set to `true` if the user entered at the beginning or exited at the end of the road object, or `false` if they entered or exited somewhere along the road object. */

Sources/MapboxCoreNavigation/CoreNavigationNavigator.swift

@@ -128,12 +128,15 @@ class Navigator {
 
 extension Navigator: ElectronicHorizonObserver {
     public func onPositionUpdated(for position: ElectronicHorizonPosition, distances: [String : MapboxNavigationNative.RoadObjectDistanceInfo]) {
-        let userInfo: [ElectronicHorizon.NotificationUserInfoKey: Any] = [
+        var userInfo: [ElectronicHorizon.NotificationUserInfoKey: Any] = [
             .positionKey: RoadGraph.Position(try! position.position()),
             .treeKey: ElectronicHorizon(try! position.tree()),
             .updatesMostProbablePathKey: try! position.type() == .UPDATE,
             .distancesByRoadObjectKey: distances.mapValues(RoadObjectDistanceInfo.init),
         ]
+        if let roadGraph = roadGraph {
+            userInfo.updateValue(roadGraph, forKey: .roadGraphIdentifierKey)
+        }
         NotificationCenter.default.post(name: .electronicHorizonDidUpdatePosition, object: nil, userInfo: userInfo)
     }
 

Sources/MapboxCoreNavigation/NavigationService.swift

@@ -249,7 +249,7 @@ public class MapboxNavigationService: NSObject, NavigationService {
         let routerType = routerType ?? DefaultRouter.self
         router = routerType.init(along: route, routeIndex: routeIndex, options: routeOptions, directions: self.directions, dataSource: self)
         NavigationSettings.shared.distanceUnit = routeOptions.locale.usesMetric ? .kilometer : .mile
-        
+
         let eventType = eventsManagerType ?? NavigationEventsManager.self
         eventsManager = eventType.init(dataSource: self, accessToken: self.directions.credentials.accessToken)
         locationManager.activityType = routeOptions.activityType

Sources/MapboxNavigation/DayStyle.swift

@@ -36,6 +36,10 @@ extension UIColor {
     class var alternativeTrafficSevere: UIColor { get { return #colorLiteral(red: 0.71, green: 0.51, blue: 0.51, alpha: 1.0) } }
     class var defaultBuildingColor: UIColor { get { return #colorLiteral(red: 0.9833194452, green: 0.9843137255, blue: 0.9331936657, alpha: 0.8019049658) } }
     class var defaultBuildingHighlightColor: UIColor { get { return #colorLiteral(red: 0.337254902, green: 0.6588235294, blue: 0.9843137255, alpha: 0.949406036) } }
+    class var intersectionAnnotationDefaultBackgroundColor: UIColor { get { return #colorLiteral(red: 1, green: 1, blue: 1, alpha: 1) } }
+    class var intersectionAnnotationSelectedBackgroundColor: UIColor { get { return #colorLiteral(red: 0.337254902, green: 0.6588235294, blue: 0.9843137255, alpha: 1) } }
+    class var intersectionAnnotationDefaultLabelColor: UIColor { get { return #colorLiteral(red: 0, green: 0, blue: 0, alpha: 1) } }
+    class var intersectionAnnotationSelectedLabelColor: UIColor { get { return #colorLiteral(red: 1, green: 1, blue: 1, alpha: 1) } }
 }
 
 extension UIColor {

Sources/MapboxNavigation/ElectronicHorizon.swift

@@ -0,0 +1,38 @@
+import MapboxCoreNavigation
+
+extension ElectronicHorizon.Edge {
+    var mpp: [ElectronicHorizon.Edge]? {
+
+        guard level == 0 else { return nil }
+
+        var mostProbablePath = [self]
+
+        for child in outletEdges {
+            if let childMPP = child.mpp {
+                mostProbablePath.append(contentsOf: childMPP)
+            }
+        }
+
+        return mostProbablePath
+    }
+    
+    func edgeNames(roadGraph: RoadGraph) -> [String] {
+        guard let metadata = roadGraph.edgeMetadata(edgeIdentifier: identifier) else {
+            return []
+        }
+        let names = metadata.names.map { name -> String in
+            switch name {
+            case .name(let name):
+                return name
+            case .code(let code):
+                return "(\(code))"
+            }
+        }
+
+        // If the road is unnamed, fall back to the road class.
+        if names.isEmpty {
+            return ["\(metadata.mapboxStreetsRoadClass.rawValue)"]
+        }
+        return names
+    }
+}

Sources/MapboxNavigation/NavigationMapView+BuildingHighlighting.swift

@@ -101,7 +101,16 @@ extension NavigationMapView {
         highlightedBuildingsLayer.paint?.fillExtrusionColor = .constant(.init(color: buildingHighlightColor))
         highlightedBuildingsLayer.paint?.fillExtrusionHeightTransition = StyleTransition(duration: 0.8, delay: 0)
         highlightedBuildingsLayer.paint?.fillExtrusionOpacityTransition = StyleTransition(duration: 0.8, delay: 0)
+
+        #if false
+        if let _ = try? mapView.style.getSource(identifier: NavigationMapView.intersectionAnnotations, type: GeoJSONSource.self).get() {
+            mapView.style.addLayer(layer: highlightedBuildingsLayer, layerPosition: LayerPosition(above: nil, below: IdentifierString.intersectionAnnotationsLayer, at: nil))
+        } else {
+            mapView.style.addLayer(layer: highlightedBuildingsLayer)
+        }
+        #else
         mapView.style.addLayer(layer: highlightedBuildingsLayer)
+        #endif
     }
 
 }

Sources/MapboxNavigation/NavigationMapView+IntersectionAnnotations.swift

@@ -0,0 +1,133 @@
+import CoreLocation
+import UIKit
+import MapboxDirections
+import MapboxCoreNavigation
+import Turf
+import MapboxMaps
+
+extension NavigationMapView {
+    
+    struct EdgeIntersection {
+        var root: ElectronicHorizon.Edge
+        var branch: ElectronicHorizon.Edge
+        var rootMetadata: ElectronicHorizon.Edge.Metadata
+        var rootShape: LineString
+        var branchMetadata: ElectronicHorizon.Edge.Metadata
+        var branchShape: LineString
+
+        var coordinate: CLLocationCoordinate2D? {
+            rootShape.coordinates.first
+        }
+
+        var annotationPoint: CLLocationCoordinate2D? {
+            guard let length = branchShape.distance() else { return nil }
+            let targetDistance = min(length / 2, Double.random(in: 15...30))
+            guard let annotationPoint = branchShape.coordinateFromStart(distance: targetDistance) else { return nil }
+            return annotationPoint
+        }
+
+        var wayName: String? {
+            guard let roadName = rootMetadata.names.first else { return nil }
+
+            switch roadName {
+            case .name(let name):
+                return name
+            case .code(let code):
+                return "(\(code))"
+            }
+        }
+        var intersectingWayName: String? {
+            guard let roadName = branchMetadata.names.first else { return nil }
+
+            switch roadName {
+            case .name(let name):
+                return name
+            case .code(let code):
+                return "(\(code))"
+            }
+        }
+
+        var incidentAngle: CLLocationDegrees {
+            return (branchMetadata.heading - rootMetadata.heading).wrap(min: 0, max: 360)
+        }
+
+        var description: String {
+            return "EdgeIntersection: root: \(wayName ?? "") intersection: \(intersectingWayName ?? "") coordinate: \(String(describing: coordinate))"
+        }
+    }
+
+    enum AnnotationTailPosition: Int {
+        case left
+        case right
+        case center
+    }
+
+    class AnnotationCacheEntry: Equatable, Hashable {
+        var wayname: String
+        var coordinate: CLLocationCoordinate2D
+        var intersection: EdgeIntersection?
+        var feature: Feature
+        var lastAccessTime: Date
+
+        init(coordinate: CLLocationCoordinate2D, wayname: String, intersection: EdgeIntersection? = nil, feature: Feature) {
+            self.wayname = wayname
+            self.coordinate = coordinate
+            self.intersection = intersection
+            self.feature = feature
+            self.lastAccessTime = Date()
+        }
+
+        static func == (lhs: AnnotationCacheEntry, rhs: AnnotationCacheEntry) -> Bool {
+            return lhs.wayname == rhs.wayname
+        }
+
+        func hash(into hasher: inout Hasher) {
+            hasher.combine(wayname.hashValue)
+        }
+    }
+
+    class AnnotationCache {
+        private let maxEntryAge = TimeInterval(30)
+        var entries = Set<AnnotationCacheEntry>()
+        var cachePruningTimer: Timer?
+
+        init() {
+            // periodically prune the cache to remove entries that have been passed already
+            cachePruningTimer = Timer.scheduledTimer(withTimeInterval: 15, repeats: true, block: { [weak self] _ in
+                self?.prune()
+            })
+        }
+
+        deinit {
+            cachePruningTimer?.invalidate()
+            cachePruningTimer = nil
+        }
+
+        func setValue(feature: Feature, coordinate: CLLocationCoordinate2D, intersection: EdgeIntersection?, for wayname: String) {
+            entries.insert(AnnotationCacheEntry(coordinate: coordinate, wayname: wayname, intersection: intersection, feature: feature))
+        }
+
+        func value(for wayname: String) -> AnnotationCacheEntry? {
+            let matchingEntry = entries.first { entry -> Bool in
+                entry.wayname == wayname
+            }
+
+            if let matchingEntry = matchingEntry {
+                // update the timestamp used for pruning the cache
+                matchingEntry.lastAccessTime = Date()
+            }
+
+            return matchingEntry
+        }
+
+        private func prune() {
+            let now = Date()
+
+            entries.filter { now.timeIntervalSince($0.lastAccessTime) > maxEntryAge }.forEach { remove($0) }
+        }
+
+        public func remove(_ entry: AnnotationCacheEntry) {
+            entries.remove(entry)
+        }
+    }
+}