1 files changed, 141 insertions, 0 deletions
diff --git a/platform/ios/demo/Examples/Swift/UserTrackingModesExample.swift b/platform/ios/demo/Examples/Swift/UserTrackingModesExample.swift
new file mode 100644
index 0000000000..66ba7c0481
--- /dev/null
+++ b/platform/ios/demo/Examples/Swift/UserTrackingModesExample.swift
@@ -0,0 +1,141 @@
+import Mapbox
+
+@objc(UserTrackingModesExample_Swift)
+
+class UserTrackingModesExample_Swift: UIViewController, MGLMapViewDelegate {
+    var mapView: MGLMapView!
+    @IBOutlet var button: UserLocationButton!
+    
+    override func viewDidLoad() {
+        super.viewDidLoad()
+        
+        mapView = MGLMapView(frame: view.bounds, styleURL: MGLStyle.darkStyleURL(withVersion: 9))
+        mapView.autoresizingMask = [.flexibleWidth, .flexibleHeight]
+        mapView.delegate = self
+        
+        mapView.tintColor = .red
+        mapView.attributionButton.tintColor = .lightGray
+        
+        view.addSubview(mapView)
+        
+        setupLocationButton()
+    }
+    
+    func mapView(_ mapView: MGLMapView, didChange mode: MGLUserTrackingMode, animated: Bool) {
+        button.updateArrow(for: mode)
+    }
+    
+    @IBAction func locationButtonTapped() {
+        var mode: MGLUserTrackingMode
+        
+        switch (mapView.userTrackingMode) {
+        case .none:
+            mode = .follow
+            break
+        case .follow:
+            mode = .followWithHeading
+            break
+        case .followWithHeading:
+            mode = .followWithCourse
+            break
+        case .followWithCourse:
+            mode = .none
+            break
+        }
+        
+        mapView.userTrackingMode = mode
+    }
+    
+    func setupLocationButton() {
+        button = UserLocationButton()
+        button.addTarget(self, action: #selector(locationButtonTapped), for: .touchUpInside)
+        button.tintColor = mapView.tintColor
+        view.addSubview(button)
+        
+        // Do some basic auto layout.
+        button.translatesAutoresizingMaskIntoConstraints = false
+        
+        let constraints = [
+            NSLayoutConstraint(item: button, attribute: .top, relatedBy: .greaterThanOrEqual, toItem: topLayoutGuide, attribute: .bottom, multiplier: 1, constant: 10),
+            NSLayoutConstraint(item: button, attribute: .leading, relatedBy: .equal, toItem: view, attribute: .leading, multiplier: 1, constant: 10),
+            NSLayoutConstraint(item: button, attribute: .height, relatedBy: .equal, toItem: nil, attribute: .notAnAttribute, multiplier: 1, constant: button.frame.size.height),
+            NSLayoutConstraint(item: button, attribute: .width, relatedBy: .equal, toItem: nil, attribute: .notAnAttribute, multiplier: 1, constant: button.frame.size.width)
+        ]
+        
+        view.addConstraints(constraints)
+    }
+    
+}
+
+class UserLocationButton : UIButton {
+    private let size: CGFloat = 80
+    private var arrow: CAShapeLayer?
+    
+    required init() {
+        super.init(frame: CGRect(x: 0, y: 0, width: size, height: size))
+    }
+    
+    required init?(coder aDecoder: NSCoder) {
+        fatalError("init(coder:) has not been implemented")
+    }
+    
+    override func layoutSubviews() {
+        backgroundColor = UIColor.black.withAlphaComponent(0.5)
+        layer.cornerRadius = 4
+        
+        layoutArrow()
+    }
+    
+    private func layoutArrow() {
+        if arrow == nil {
+            let arrow = CAShapeLayer()
+            arrow.path = arrowPath()
+            arrow.bounds = CGRect(x: 0, y: 0, width: size / 2, height: size / 2)
+            arrow.position = CGPoint(x: size / 2, y: size / 2)
+            arrow.shouldRasterize = true
+            arrow.rasterizationScale = UIScreen.main.scale
+            arrow.drawsAsynchronously = true
+            
+            self.arrow = arrow
+            updateArrow(for: .none)
+            layer.addSublayer(self.arrow!)
+        }
+    }
+    
+    private func arrowPath() -> CGPath {
+        let max: CGFloat = size / 2
+        
+        let bezierPath = UIBezierPath()
+        bezierPath.move(to: CGPoint(x: max * 0.5, y: 0))
+        bezierPath.addLine(to: CGPoint(x: max * 0.1, y: max))
+        bezierPath.addLine(to: CGPoint(x: max * 0.5, y: max * 0.65))
+        bezierPath.addLine(to: CGPoint(x: max * 0.9, y: max))
+        bezierPath.addLine(to: CGPoint(x: max * 0.5, y: 0))
+        bezierPath.close()
+        
+        return bezierPath.cgPath
+    }
+    
+    func updateArrow(for mode: MGLUserTrackingMode) {
+        var stroke: CGColor
+        switch (mode) {
+        case .none:
+            stroke = UIColor.white.cgColor
+        case .follow:
+            stroke = tintColor.cgColor
+        case .followWithHeading, .followWithCourse:
+            stroke = UIColor.clear.cgColor
+        }
+        arrow!.strokeColor = stroke
+        
+        // Re-center the arrow, based on its current orientation.
+        arrow!.position = (mode == .none || mode == .followWithCourse) ? CGPoint(x: size / 2, y: size / 2) : CGPoint(x: size / 2 + 2, y: size / 2 - 2)
+        
+        arrow!.fillColor = (mode == .none || mode == .follow) ? UIColor.clear.cgColor : tintColor.cgColor
+        
+        let rotation: CGFloat = (mode == .follow || mode == .followWithHeading) ? 0.66 : 0
+        arrow!.setAffineTransform(CGAffineTransform.identity.rotated(by: rotation))
+        
+        layoutIfNeeded()
+    }
+}