Expand Clusters on Tap

Sources/MapLibreSwiftUI/Examples/Layers.swift

@@ -123,6 +123,13 @@ let clustered = ShapeSource(identifier: "points", options: [.clustered: true, .c
             .iconColor(.white)
             .predicate(NSPredicate(format: "cluster != YES"))
     }
+    .onTapMapGesture(on: ["simple-circles-non-clusters"], onTapChanged: { _, features in
+        print("Tapped on \(features.first)")
+    })
+    .expandClustersOnTapping(clusteredLayers: [ClusterLayer(
+        layerIdentifier: "simple-circles-clusters",
+        sourceIdentifier: "points"
+    )])
     .ignoresSafeArea(.all)
 }
 

Sources/MapLibreSwiftUI/Extensions/MapView/MapViewGestures.swift

@@ -58,6 +58,29 @@ extension MapView {
             return
         }
 
+        if let clusteredLayers {
+            if let gestureRecognizer = sender as? UITapGestureRecognizer, gestureRecognizer.numberOfTouches == 1 {
+                let point = gestureRecognizer.location(in: sender.view)
+                for clusteredLayer in clusteredLayers {
+                    let features = mapView.visibleFeatures(
+                        at: point,
+                        styleLayerIdentifiers: [clusteredLayer.layerIdentifier]
+                    )
+                    if let cluster = features.first as? MLNPointFeatureCluster,
+                       let source = mapView.style?
+                       .source(withIdentifier: clusteredLayer.sourceIdentifier) as? MLNShapeSource
+                    {
+                        let zoomLevel = source.zoomLevel(forExpanding: cluster)
+
+                        if zoomLevel > 0 {
+                            mapView.setCenter(cluster.coordinate, zoomLevel: zoomLevel, animated: true)
+                            break // since we can only zoom on one thing, we can abort the for loop here
+                        }
+                    }
+                }
+            }
+        }
+
         // Process the gesture into a context response.
         let context = processContextFromGesture(mapView, gesture: gesture, sender: sender)
         // Run the context through the gesture held on the MapView (emitting to the MapView modifier).
@@ -97,3 +120,14 @@ extension MapView {
                                  coordinate: mapView.convert(point, toCoordinateFrom: mapView))
     }
 }
+
+/// Provides the layer identifier and it's source identifier.
+public struct ClusterLayer {
+    public let layerIdentifier: String
+    public let sourceIdentifier: String
+
+    public init(layerIdentifier: String, sourceIdentifier: String) {
+        self.layerIdentifier = layerIdentifier
+        self.sourceIdentifier = sourceIdentifier
+    }
+}

Sources/MapLibreSwiftUI/MapView.swift

@@ -28,6 +28,8 @@ public struct MapView: UIViewRepresentable {
 
     private var locationManager: MLNLocationManager?
 
+    var clusteredLayers: [ClusterLayer]?
+
     public init(
         styleURL: URL,
         camera: Binding<MapViewCamera> = .constant(.default()),

Sources/MapLibreSwiftUI/MapViewModifiers.swift

@@ -108,6 +108,18 @@ public extension MapView {
         return newMapView
     }
 
+    /// Add a default implementation for tapping clustered features. When tapped, the map zooms so that the cluster is
+    /// expanded.
+    /// - Parameter clusteredLayers: An array of layers to monitor that can contain clustered features.
+    /// - Returns: The modified MapView
+    func expandClustersOnTapping(clusteredLayers: [ClusterLayer]) -> MapView {
+        var newMapView = self
+
+        newMapView.clusteredLayers = clusteredLayers
+
+        return newMapView
+    }
+
     func mapViewContentInset(_ inset: UIEdgeInsets) -> Self {
         var result = self