Merge pull request #23 from hactar/enhancement/camera-bounding-box

Add support for camera bounding box

Author: ianthetechie

Sources/MapLibreSwiftUI/Extensions/MapLibre/MLNMapViewCameraUpdating.swift

@@ -13,6 +13,12 @@ protocol MLNMapViewCameraUpdating: AnyObject {
                    direction: CLLocationDirection,
                    animated: Bool)
     func setZoomLevel(_ zoomLevel: Double, animated: Bool)
+    func setVisibleCoordinateBounds(
+        _ bounds: MLNCoordinateBounds,
+        edgePadding: UIEdgeInsets,
+        animated: Bool,
+        completionHandler: (() -> Void)?
+    )
 }
 
 extension MLNMapView: MLNMapViewCameraUpdating {

Sources/MapLibreSwiftUI/MapViewCoordinator.swift

@@ -63,7 +63,12 @@ public class MapViewCoordinator: NSObject {
         case .trackingUserLocationWithCourse:
             mapView.userTrackingMode = .followWithCourse
             mapView.setZoomLevel(camera.zoom, animated: false)
-        case .rect, .showcase:
+        case let .rect(boundingBox, padding):
+            mapView.setVisibleCoordinateBounds(boundingBox,
+                                               edgePadding: padding,
+                                               animated: animated,
+                                               completionHandler: nil)
+        case .showcase:
             // TODO: Need a method these/or to finalize a goal here.
             break
         }

Sources/MapLibreSwiftUI/Models/MapCamera/CameraState.swift

@@ -25,7 +25,10 @@ public enum CameraState: Hashable {
     case trackingUserLocationWithCourse
 
     /// Centered on a bounding box/rectangle.
-    case rect(northeast: CLLocationCoordinate2D, southwest: CLLocationCoordinate2D) // TODO: make a bounding box?
+    case rect(
+        boundingBox: MLNCoordinateBounds,
+        edgePadding: UIEdgeInsets = .init(top: 20, left: 20, bottom: 20, right: 20)
+    )
 
     /// Showcasing GeoJSON, Polygons, etc.
     case showcase(shapeCollection: MLNShapeCollection)
@@ -42,10 +45,30 @@ extension CameraState: CustomDebugStringConvertible {
             "CameraState.trackingUserLocationWithHeading"
         case .trackingUserLocationWithCourse:
             "CameraState.trackingUserLocationWithCourse"
-        case let .rect(northeast: northeast, southwest: southwest):
-            "CameraState.rect(northeast: \(northeast), southwest: \(southwest))"
+        case let .rect(boundingBox: boundingBox, _):
+            "CameraState.rect(northeast: \(boundingBox.ne), southwest: \(boundingBox.sw))"
         case let .showcase(shapeCollection: shapeCollection):
             "CameraState.showcase(shapeCollection: \(shapeCollection))"
         }
     }
 }
+
+extension MLNCoordinateBounds: Equatable, Hashable {
+    public func hash(into hasher: inout Hasher) {
+        hasher.combine(ne)
+        hasher.combine(sw)
+    }
+
+    public static func == (lhs: MLNCoordinateBounds, rhs: MLNCoordinateBounds) -> Bool {
+        lhs.ne == rhs.ne && lhs.sw == rhs.sw
+    }
+}
+
+extension UIEdgeInsets: Hashable {
+    public func hash(into hasher: inout Hasher) {
+        hasher.combine(left)
+        hasher.combine(right)
+        hasher.combine(top)
+        hasher.combine(bottom)
+    }
+}

Sources/MapLibreSwiftUI/Models/MapCamera/MapViewCamera.swift

@@ -118,5 +118,21 @@ public struct MapViewCamera: Hashable {
                       lastReasonForChange: .programmatic)
     }
 
-    // TODO: Create init methods for other camera states once supporting materials are understood (e.g. BoundingBox)
+    /// Positions the camera to show a specific region in the MapView.
+    ///
+    /// - Parameters:
+    ///   - box: Set the desired bounding box. This is a one time event and the user can manipulate by moving the map.
+    ///   - edgePadding: Set the edge insets that should be applied before positioning the map.
+    /// - Returns: The MapViewCamera representing the scenario
+    public static func boundingBox(
+        _ box: MLNCoordinateBounds,
+        edgePadding: UIEdgeInsets = .init(top: 20, left: 20, bottom: 20, right: 20)
+    ) -> MapViewCamera {
+        // zoom, pitch & direction are ignored.
+        MapViewCamera(state: .rect(boundingBox: box, edgePadding: edgePadding),
+                      zoom: 1,
+                      pitch: Defaults.pitch,
+                      direction: Defaults.direction,
+                      lastReasonForChange: .programmatic)
+    }
 }

Tests/MapLibreSwiftUITests/Models/MapCamera/CameraStateTests.swift

@@ -35,8 +35,9 @@ final class CameraStateTests: XCTestCase {
         let northeast = CLLocationCoordinate2D(latitude: 12.3, longitude: 23.4)
         let southwest = CLLocationCoordinate2D(latitude: 34.5, longitude: 45.6)
 
-        let state: CameraState = .rect(northeast: northeast, southwest: southwest)
-        XCTAssertEqual(state, .rect(northeast: northeast, southwest: southwest))
+        let state: CameraState = .rect(boundingBox: .init(sw: southwest, ne: northeast))
+        XCTAssertEqual(state, .rect(boundingBox: .init(sw: southwest, ne: northeast)))
+
         XCTAssertEqual(
             String(describing: state),
             "CameraState.rect(northeast: CLLocationCoordinate2D(latitude: 12.3, longitude: 23.4), southwest: CLLocationCoordinate2D(latitude: 34.5, longitude: 45.6))"

Tests/MapLibreSwiftUITests/Models/MapCamera/MapViewCameraTests.swift

@@ -1,4 +1,5 @@
 import CoreLocation
+import MapLibre
 import XCTest
 @testable import MapLibreSwiftUI
 
@@ -45,5 +46,20 @@ final class MapViewCameraTests: XCTestCase {
         XCTAssertEqual(camera.direction, 0)
     }
 
+    func testBoundingBox() {
+        let southwest = CLLocationCoordinate2D(latitude: 24.6056011, longitude: 46.67369842529297)
+        let northeast = CLLocationCoordinate2D(latitude: 24.6993808, longitude: 46.7709285)
+        let bounds = MLNCoordinateBounds(sw: southwest, ne: northeast)
+        let camera = MapViewCamera.boundingBox(bounds)
+
+        XCTAssertEqual(
+            camera.state,
+            .rect(boundingBox: bounds, edgePadding: .init(top: 20, left: 20, bottom: 20, right: 20))
+        )
+        XCTAssertEqual(camera.zoom, 1)
+        XCTAssertEqual(camera.pitch, .free)
+        XCTAssertEqual(camera.direction, 0)
+    }
+
     // TODO: Add additional camera tests once behaviors are added (e.g. rect)
 }