Feat/map camera and layer mods

.swiftpm/xcode/xcshareddata/xcschemes/MapLibreSwiftDSL.xcscheme

@@ -1,6 +1,6 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <Scheme
-   LastUpgradeVersion = "1500"
+   LastUpgradeVersion = "1510"
    version = "1.7">
    <BuildAction
       parallelizeBuildables = "YES"

.swiftpm/xcode/xcshareddata/xcschemes/MapLibreSwiftUI-Package.xcscheme

@@ -1,6 +1,6 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <Scheme
-   LastUpgradeVersion = "1500"
+   LastUpgradeVersion = "1510"
    version = "1.7">
    <BuildAction
       parallelizeBuildables = "YES"

.swiftpm/xcode/xcshareddata/xcschemes/MapLibreSwiftUI.xcscheme

@@ -1,6 +1,6 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <Scheme
-   LastUpgradeVersion = "1500"
+   LastUpgradeVersion = "1510"
    version = "1.7">
    <BuildAction
       parallelizeBuildables = "YES"

Package.swift

@@ -42,8 +42,8 @@ let package = Package(
         ),
         .binaryTarget(
             name: "MapLibre",
-            url: "https://github.com/maplibre/maplibre-native/releases/download/ios-v6.0.0-preda45706601c7ccc6d922a8fcddfc62ff7c8f480d/MapLibre.dynamic.xcframework.zip",
-            checksum: "37e621c0c7c1f589f0a125816155ba443000d78b80649d85a9b8b3d19144836c"
+            url: "https://github.com/maplibre/maplibre-native/releases/download/ios-v6.0.0-pre9fbcb031f019048f21fdfcb57b80f4451cdecfd9/MapLibre.dynamic.xcframework.zip",
+            checksum: "929bbc3f24740df360bf447acf08bd102cf4baf12a6bc099f42e5fb8b5130cf4"
         ),
         .target(
             name: "MapLibreSwiftUI",

Sources/MapLibreSwiftDSL/MapViewContentBuilder.swift

@@ -0,0 +1,34 @@
+import Foundation
+
+@resultBuilder
+public enum MapViewContentBuilder {
+
+    public static func buildBlock(_ layers: [StyleLayerDefinition]...) -> [StyleLayerDefinition] {
+        return layers.flatMap { $0 }
+    }
+
+    public static func buildOptional(_ layers: [StyleLayerDefinition]?) -> [StyleLayerDefinition] {
+        return layers ?? []
+    }
+
+    public static func buildExpression(_ layer: StyleLayerDefinition) -> [StyleLayerDefinition] {
+        return [layer]
+    }
+
+    public static func buildExpression(_ expression: Void) -> [StyleLayerDefinition] {
+        return []
+    }
+
+    public static func buildExpression(_ styleCollection: StyleLayerCollection) -> [StyleLayerDefinition] {
+        return styleCollection.layers
+    }
+
+
+    public static func buildEither(first layer: [StyleLayerDefinition]) -> [StyleLayerDefinition] {
+        return layer
+    }
+
+    public static func buildEither(second layer: [StyleLayerDefinition]) -> [StyleLayerDefinition] {
+        return layer
+    }
+}

Sources/MapLibreSwiftDSL/Style Layers/StyleLayerCollection.swift

@@ -0,0 +1,6 @@
+import Foundation
+
+public protocol StyleLayerCollection {
+
+    @MapViewContentBuilder var layers: [StyleLayerDefinition] { get }
+}

Sources/MapLibreSwiftUI/Examples/Camera.swift

@@ -4,26 +4,27 @@ import SwiftUI
 private let switzerland = CLLocationCoordinate2D(latitude: 46.801111, longitude: 8.226667)
 
 struct CameraDirectManipulationPreview: View {
-    @State private var camera = MapView.Camera.centerAndZoom(switzerland, 4)
+    @State private var camera = MapViewCamera.center(switzerland, zoom: 4)
 
     let styleURL: URL
 
     var body: some View {
         MapView(styleURL: styleURL, camera: $camera)
             .overlay(alignment: .bottom, content: {
-                switch camera {
-                case .centerAndZoom(let coord, let zoom):
-                    Text("\(coord.latitude), \(coord.longitude) z \(zoom ?? 0)")
-                        .padding()
-                        .background(in: RoundedRectangle(cornerRadius: 8), 
-                                    fillStyle: .init())
-                        .padding(.bottom, 42)
-                }
+                Text("\(camera.coordinate.latitude), \(camera.coordinate.longitude) z \(camera.zoom ?? 0)")
+                    .padding()
+                    .background(
+                        Rectangle()
+                            .foregroundColor(.black)
+                            .cornerRadius(8)
+                    )
+
+                    .padding(.bottom, 42)
             })
         .task {
             try! await Task.sleep(nanoseconds: 3 * NSEC_PER_SEC)
 
-            camera = MapView.Camera.centerAndZoom(switzerland, 6)
+            camera = MapViewCamera.center(switzerland, zoom: 6)
         }
     }
 }

Sources/MapLibreSwiftUI/Examples/Polyline.swift

@@ -7,7 +7,7 @@ struct PolylinePreview: View {
     let styleURL: URL
 
     var body: some View {
-        MapView(styleURL: styleURL, initialCamera: MapView.Camera.centerAndZoom(samplePedestrianWaypoints.first!, 14)) {
+        MapView(styleURL: styleURL, initialCamera: MapViewCamera.center(samplePedestrianWaypoints.first!, zoom: 14)) {
             // Note: This line does not add the source to the style as if it
             // were a statement in an imperative programming language.
             // The source is added automatically if a layer references it.

Sources/MapLibreSwiftUI/MapView.swift

@@ -2,31 +2,31 @@ import SwiftUI
 import InternalUtils
 import MapLibre
 import MapLibreSwiftDSL
-
+import MapLibreSwiftUI
 
 public struct MapView: UIViewRepresentable {
-    // TODO: Support MLNStyle as well; having a DSL for that would be nice
-    enum MapStyleSource {
-        case url(URL)
-    }
-
-    public enum Camera {
-        case centerAndZoom(CLLocationCoordinate2D, Double?)
-    }
-
-    var camera: Binding<Camera>?
+
+    public private(set) var camera: Binding<MapViewCamera>?
 
-    let styleSource: MapStyleSource
-    let userLayers: [StyleLayerDefinition]
+    public let styleSource: MapStyleSource
+    public let userLayers: [StyleLayerDefinition]
 
-    public init(styleURL: URL, camera: Binding<Camera>? = nil, @MapViewContentBuilder _ makeMapContent: () -> [StyleLayerDefinition] = { [] }) {
+    public init(
+        styleURL: URL,
+        camera: Binding<MapViewCamera>? = nil,
+        @MapViewContentBuilder _ makeMapContent: () -> [StyleLayerDefinition] = { [] }
+    ) {
         self.styleSource = .url(styleURL)
         self.camera = camera
 
         userLayers = makeMapContent()
     }
 
-    public init(styleURL: URL, initialCamera: Camera, @MapViewContentBuilder _ makeMapContent: () -> [StyleLayerDefinition] = { [] }) {
+    public init(
+        styleURL: URL,
+        initialCamera: MapViewCamera,
+        @MapViewContentBuilder _ makeMapContent: () -> [StyleLayerDefinition] = { [] }
+    ) {
         self.init(styleURL: styleURL, camera: .constant(initialCamera), makeMapContent)
     }
 
@@ -36,7 +36,8 @@ public struct MapView: UIViewRepresentable {
         // Storage of variables as they were previously; these are snapshot
         // every update cycle so we can avoid unnecessary updates
         private var snapshotUserLayers: [StyleLayerDefinition] = []
-
+        var snapshotCamera: MapViewCamera?
+
         init(parent: MapView) {
             self.parent = parent
         }
@@ -58,7 +59,8 @@ public struct MapView: UIViewRepresentable {
 
         public func mapView(_ mapView: MLNMapView, regionDidChangeAnimated animated: Bool) {
             DispatchQueue.main.async {
-                self.parent.camera?.wrappedValue = .centerAndZoom(mapView.centerCoordinate, mapView.zoomLevel)
+                self.parent.camera?.wrappedValue = .center(mapView.centerCoordinate,
+                                                           zoom:  mapView.zoomLevel)
             }
         }
 
@@ -161,7 +163,7 @@ public struct MapView: UIViewRepresentable {
             mapView.styleURL = styleURL
         }
 
-        updateMapCamera(mapView, animated: false)
+        updateMapCamera(mapView, context: context, animated: false)
 
         // TODO: Make this settable via a modifier
         mapView.logoView.isHidden = true
@@ -182,28 +184,22 @@ public struct MapView: UIViewRepresentable {
         // FIXME: This isn't exactly telling us if the *map* is loaded, and the docs for setCenter say it needs t obe.
         let isStyleLoaded = mapView.style != nil
 
-        updateMapCamera(mapView, animated: isStyleLoaded)
+        updateMapCamera(mapView, context: context, animated: isStyleLoaded)
     }
 
-    private func updateMapCamera(_ mapView: MLNMapView, animated: Bool) {
-        if let camera = self.camera {
-            switch camera.wrappedValue {
-            case .centerAndZoom(let center, let zoom):
-                // TODO: Determine if MapLibre is smart enough to keep animating to the same place multiple times; if not, add a check here to prevent suprious updates.
-                if let z = zoom {
-                    mapView.setCenter(center, zoomLevel: z, animated: animated)
-                } else {
-                    mapView.setCenter(center, animated: animated)
-                }
-            }
+    private func updateMapCamera(_ mapView: MLNMapView, context: Context, animated: Bool) {
+        guard let newCamera = self.camera?.wrappedValue,
+              context.coordinator.snapshotCamera != newCamera else {
+            // Exit early - the camera has not changed.
+            return
         }
-    }
-}
-
-@resultBuilder
-public enum MapViewContentBuilder {
-    public static func buildBlock(_ layers: StyleLayerDefinition...) -> [StyleLayerDefinition] {
-        return layers
+        
+        mapView.setCenter(newCamera.coordinate,
+                          zoomLevel: newCamera.zoom,
+                          direction: newCamera.course,
+                          animated: animated)
+        
+        context.coordinator.snapshotCamera = newCamera
     }
 }
 

Sources/MapLibreSwiftUI/Models/MapCamera/CameraState.swift

@@ -0,0 +1,37 @@
+import Foundation
+import MapLibre
+
+/// The CameraState is used to understand the current context of the MapView's camera.
+public enum CameraState {
+
+    /// Centered on a coordinate
+    case centered
+
+    /// The camera is currently following a location provider.
+    case userLocation
+
+    /// Centered on a bounding box/rectangle.
+    case rect
+
+    /// Showcasing a GeoJSON/Polygon
+    case showcase
+}
+
+extension CameraState: Equatable {
+
+    public static func ==(lhs: CameraState, rhs: CameraState) -> Bool {
+        switch (lhs, rhs) {
+
+        case (.centered, .centered):
+            return true
+        case (.userLocation, .userLocation):
+            return true
+        case (.rect, .rect):
+            return true
+        case (.showcase, .showcase):
+            return true
+        default:
+            return false
+        }
+    }
+}

Sources/MapLibreSwiftUI/Models/MapCamera/MapViewCamera.swift

@@ -0,0 +1,69 @@
+import Foundation
+import CoreLocation
+
+public struct MapViewCamera {
+
+    public var state: CameraState
+    public var coordinate: CLLocationCoordinate2D
+    public var zoom: Double
+    public var pitch: Double
+    public var course: CLLocationDirection
+
+    /// A backup camera centered at 0.0, 0.0. This is typically used as a backup,
+    /// pre-load for an expected camera update (e.g. before a location provider produces
+    /// it's first location).
+    ///
+    /// - Returns: The constructed MapViewCamera.
+    public static func backup() -> MapViewCamera {
+        return MapViewCamera(state: .centered,
+                             coordinate: CLLocationCoordinate2D(latitude: 0, longitude: 0),
+                             zoom: 10,
+                             pitch: 90,
+                             course: 0)
+    }
+
+    /// Center the map on a specific location.
+    ///
+    /// - Parameters:
+    ///   - coordinate: The coordinate to center the map on.
+    ///   - zoom: The zoom level.
+    ///   - pitch: The camera pitch. Default is 90 (straight down).
+    ///   - course: The course. Default is 0 (North).
+    /// - Returns: The constructed MapViewCamera.
+    public static func center(_ coordinate: CLLocationCoordinate2D,
+                              zoom: Double,
+                              pitch: Double = 90.0,
+                              course: Double = 0) -> MapViewCamera {
+
+        return MapViewCamera(state: .centered,
+                             coordinate: coordinate,
+                             zoom: zoom,
+                             pitch: pitch,
+                             course: course)
+    }
+
+    public static func userLocation(_ location: CLLocation,
+                                    zoom: Double,
+                                    pitch: Double = 90.0) -> MapViewCamera {
+
+        return MapViewCamera(state: .userLocation,
+                             coordinate: location.coordinate,
+                             zoom: zoom,
+                             pitch: pitch,
+                             course: location.course)
+    }
+
+    // TODO: Create init methods for other camera states once supporting materials are understood (e.g. BoundingBox)
+}
+
+extension MapViewCamera: Equatable {
+
+    public static func ==(lhs: MapViewCamera, rhs: MapViewCamera) -> Bool {
+        return lhs.state == rhs.state
+            && lhs.coordinate.latitude == rhs.coordinate.latitude
+            && lhs.coordinate.longitude == rhs.coordinate.longitude
+            && lhs.zoom == rhs.zoom
+            && lhs.pitch == rhs.pitch
+            && lhs.course == rhs.course
+    }
+}

Sources/MapLibreSwiftUI/Models/MapStyleSource.swift

@@ -0,0 +1,6 @@
+import Foundation
+
+// TODO: Support MLNStyle as well; having a DSL for that would be nice
+public enum MapStyleSource {
+    case url(URL)
+}