Feature Gestures

Sources/MapLibreSwiftUI/Examples/Gestures.swift

@@ -0,0 +1,32 @@
+import CoreLocation
+import MapLibre
+import MapLibreSwiftDSL
+import SwiftUI
+
+#Preview("Tappable Circles") {
+    let tappableID = "simple-circles"
+    return MapView(styleURL: demoTilesURL) {
+        // Simple symbol layer demonstration with an icon
+        CircleStyleLayer(identifier: tappableID, source: pointSource)
+            .radius(16)
+            .color(.systemRed)
+            .strokeWidth(2)
+            .strokeColor(.white)
+
+        SymbolStyleLayer(identifier: "simple-symbols", source: pointSource)
+            .iconImage(UIImage(systemName: "mappin")!.withRenderingMode(.alwaysTemplate))
+            .iconColor(.white)
+    }
+    .onTapMapGesture(on: [tappableID], onTapChanged: { _, features in
+        print("Tapped on \(features.first)")
+    })
+    .ignoresSafeArea(.all)
+}
+
+#Preview("Tappable Countries") {
+    MapView(styleURL: demoTilesURL)
+        .onTapMapGesture(on: ["countries-fill"], onTapChanged: { _, features in
+            print("Tapped on \(features.first)")
+        })
+        .ignoresSafeArea(.all)
+}

Sources/MapLibreSwiftUI/Extensions/MapView/MapViewGestures.swift

@@ -15,6 +15,17 @@ extension MapView {
             let gestureRecognizer = UITapGestureRecognizer(target: context.coordinator,
                                                            action: #selector(context.coordinator.captureGesture(_:)))
             gestureRecognizer.numberOfTapsRequired = numberOfTaps
+            if numberOfTaps == 1 {
+                // If a user double taps to zoom via the built in gesture, a normal
+                // tap should not be triggered.
+                if let doubleTapRecognizer = mapView.gestureRecognizers?
+                    .first(where: {
+                        $0 is UITapGestureRecognizer && ($0 as! UITapGestureRecognizer).numberOfTapsRequired == 2
+                    })
+                {
+                    gestureRecognizer.require(toFail: doubleTapRecognizer)
+                }
+            }
             mapView.addGestureRecognizer(gestureRecognizer)
             gesture.gestureRecognizer = gestureRecognizer
 
@@ -50,7 +61,14 @@ extension MapView {
         // 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).
-        gesture.onChange(context)
+        switch gesture.onChange {
+        case let .context(action):
+            action(context)
+        case let .feature(action, layers):
+            let point = sender.location(in: sender.view)
+            let features = mapView.visibleFeatures(at: point, styleLayerIdentifiers: layers)
+            action(context, features)
+        }
     }
 
     /// Convert the sender data into a MapGestureContext

Sources/MapLibreSwiftUI/MapView.swift

@@ -10,6 +10,7 @@ public struct MapView: UIViewRepresentable {
     let userLayers: [StyleLayerDefinition]
 
     var gestures = [MapGesture]()
+
     var onStyleLoaded: ((MLNStyle) -> Void)?
 
     public var mapViewContentInset: UIEdgeInsets = .zero

Sources/MapLibreSwiftUI/MapViewModifiers.swift

@@ -50,7 +50,8 @@ public extension MapView {
     ///
     /// - Parameters:
     ///   - count: The number of taps required to run the gesture.
-    ///   - onTapChanged: Emits the context whenever the gesture changes (e.g. began, ended, etc).
+    ///   - onTapChanged: Emits the context whenever the gesture changes (e.g. began, ended, etc), that also contains
+    /// information like the latitude and longitude of the tap.
     /// - Returns: The modified map view.
     func onTapMapGesture(count: Int = 1,
                          onTapChanged: @escaping (MapGestureContext) -> Void) -> MapView
@@ -59,7 +60,30 @@ public extension MapView {
 
         // Build the gesture and link it to the map view.
         let gesture = MapGesture(method: .tap(numberOfTaps: count),
-                                 onChange: onTapChanged)
+                                 onChange: .context(onTapChanged))
+        newMapView.gestures.append(gesture)
+
+        return newMapView
+    }
+
+    /// Add an tap gesture handler to the MapView that returns any visible map features that were tapped.
+    ///
+    /// - Parameters:
+    ///   - count: The number of taps required to run the gesture.
+    ///   - on layers: The set of layer ids that you would like to check for visible features that were tapped. If no
+    /// set is provided, all map layers are checked.
+    ///   - onTapChanged: Emits the context whenever the gesture changes (e.g. began, ended, etc), that also contains
+    /// information like the latitude and longitude of the tap. Also emits an array of map features that were tapped.
+    /// Returns an empty array when nothing was tapped on the "on" layer ids that were provided.
+    /// - Returns: The modified map view.
+    func onTapMapGesture(count: Int = 1, on layers: Set<String>?,
+                         onTapChanged: @escaping (MapGestureContext, [any MLNFeature]) -> Void) -> MapView
+    {
+        var newMapView = self
+
+        // Build the gesture and link it to the map view.
+        let gesture = MapGesture(method: .tap(numberOfTaps: count),
+                                 onChange: .feature(onTapChanged, layers: layers))
         newMapView.gestures.append(gesture)
 
         return newMapView
@@ -78,7 +102,7 @@ public extension MapView {
 
         // Build the gesture and link it to the map view.
         let gesture = MapGesture(method: .longPress(minimumDuration: minimumDuration),
-                                 onChange: onPressChanged)
+                                 onChange: .context(onPressChanged))
         newMapView.gestures.append(gesture)
 
         return newMapView

Sources/MapLibreSwiftUI/Models/Gesture/MapGesture.swift

@@ -1,3 +1,4 @@
+import MapLibre
 import UIKit
 
 public class MapGesture: NSObject {
@@ -19,7 +20,7 @@ public class MapGesture: NSObject {
     let method: Method
 
     /// The onChange action that runs when the gesture changes on the map view.
-    let onChange: (MapGestureContext) -> Void
+    let onChange: GestureAction
 
     /// The underlying gesture recognizer
     weak var gestureRecognizer: UIGestureRecognizer?
@@ -29,8 +30,13 @@ public class MapGesture: NSObject {
     /// - Parameters:
     ///   - method: The gesture recognizer method
     ///   - onChange: The action to perform when the gesture is changed
-    init(method: Method, onChange: @escaping (MapGestureContext) -> Void) {
+    init(method: Method, onChange: GestureAction) {
         self.method = method
         self.onChange = onChange
     }
 }
+
+public enum GestureAction {
+    case context((MapGestureContext) -> Void)
+    case feature((MapGestureContext, [any MLNFeature]) -> Void, layers: Set<String>?)
+}

Tests/MapLibreSwiftUITests/MapView/MapViewGestureTests.swift

@@ -28,9 +28,9 @@ final class MapViewGestureTests: XCTestCase {
     // MARK: Gesture Processing
 
     @MainActor func testTapGesture() {
-        let gesture = MapGesture(method: .tap(numberOfTaps: 2)) { _ in
+        let gesture = MapGesture(method: .tap(numberOfTaps: 2), onChange: .context { _ in
             // Do nothing
-        }
+        })
 
         let mockTapGesture = MockUIGestureRecognizing()
 
@@ -53,9 +53,9 @@ final class MapViewGestureTests: XCTestCase {
     }
 
     @MainActor func testLongPressGesture() {
-        let gesture = MapGesture(method: .longPress(minimumDuration: 1)) { _ in
+        let gesture = MapGesture(method: .longPress(minimumDuration: 1), onChange: .context { _ in
             // Do nothing
-        }
+        })
 
         let mockTapGesture = MockUIGestureRecognizing()
 

Tests/MapLibreSwiftUITests/Models/Gesture/MapGestureTests.swift

@@ -4,31 +4,39 @@ import XCTest
 final class MapGestureTests: XCTestCase {
     func testTapGestureDefaults() {
         let gesture = MapGesture(method: .tap(),
-                                 onChange: { _ in })
+                                 onChange: .context { _ in
+
+                                 })
 
         XCTAssertEqual(gesture.method, .tap())
         XCTAssertNil(gesture.gestureRecognizer)
     }
 
     func testTapGesture() {
         let gesture = MapGesture(method: .tap(numberOfTaps: 3),
-                                 onChange: { _ in })
+                                 onChange: .context { _ in
+
+                                 })
 
         XCTAssertEqual(gesture.method, .tap(numberOfTaps: 3))
         XCTAssertNil(gesture.gestureRecognizer)
     }
 
     func testLongPressGestureDefaults() {
         let gesture = MapGesture(method: .longPress(),
-                                 onChange: { _ in })
+                                 onChange: .context { _ in
+
+                                 })
 
         XCTAssertEqual(gesture.method, .longPress())
         XCTAssertNil(gesture.gestureRecognizer)
     }
 
     func testLongPressGesture() {
         let gesture = MapGesture(method: .longPress(minimumDuration: 3),
-                                 onChange: { _ in })
+                                 onChange: .context { _ in
+
+                                 })
 
         XCTAssertEqual(gesture.method, .longPress(minimumDuration: 3))
         XCTAssertNil(gesture.gestureRecognizer)