[MAPSIOS-1272] Add support for style transitions to StyleDSL (#2045)

Enables style transitions in the style DSL by creating a TransitionOptions struct

Apps/Examples/Examples/SwiftUI Examples/DynamicStylingExample.swift

@@ -23,6 +23,7 @@ struct DynamicStylingExample: View {
 
     @State var connectionKind = ConnectionComponent.Kind.line
     @State var settingsHeight = 0.0
+    @State var styleTransitions = false
     @State var cities = CityCollection.northern
     @State var pinFeatures: FeaturesRef?
     @State var connectionFeatures: FeaturesRef?
@@ -68,6 +69,9 @@ struct DynamicStylingExample: View {
                     StyleImage(id: "pin-icon", image: pinIcon.image)
                     SymbolLayer(id: "pin", source: "points")
                         .iconImage("pin-icon")
+                    if styleTransitions {
+                        TransitionOptions(duration: 5)
+                    }
                 }
 
                 if let route {
@@ -129,6 +133,7 @@ struct DynamicStylingExample: View {
 
             Toggle("Custom Atmosphere", isOn: $customAtmosphere)
             Toggle("Custom Lights", isOn: $customLights)
+            Toggle("Transition styles slowly", isOn: $styleTransitions)
         }
         .padding(10)
         .floating(RoundedRectangle(cornerRadius: 10))

CHANGELOG.md

@@ -4,8 +4,9 @@ Mapbox welcomes participation and contributions from everyone.
 
 ## main
 
-### Breaking changes ⚠️
+### Potentially breaking changes ⚠️
 * Experimental `MapStyle` no longer conforms to Equatable.
+* `TransitionOptions` is now a Swift struct rather than an Objective-C class.
 
 ### Features ✨ and improvements 🏁
 * Introduce an experimental Style DSL, enabling developers to add map style content like Sources, Layers, Style Images, Terrain, Light and Atmosphere to their map style at runtime in a declarative pattern. See the documentation [here](https://docs.mapbox.com/ios/maps/api/11.2.0-beta.1/documentation/mapboxmaps/style-dsl) for more information. For SwiftUI users, this Style DSL provides a more natural approach to manipulating content.

Sources/MapboxMaps/Documentation.docc/API Catalogs/CoreMapsInternal.md

@@ -35,3 +35,4 @@ Maps rendering SDK also known as GL-Native. These are for internal use only.
 - ``MapLoadedCallback``
 - ``StyleImageRemoveUnusedCallback``
 - ``StyleLoadedCallback``
+- ``TransitionOptions-class``

Sources/MapboxMaps/Documentation.docc/API Catalogs/Layer Property Values.md

@@ -39,7 +39,7 @@
 - ``TextTranslateAnchor``
 - ``TextWritingMode``
 - ``Visibility``
-- ``TransitionOptions``
+- ``TransitionOptions-struct``
 - ``ModelScaleMode``
 
 <!-- Next two are arguable regarding it's category -->

Sources/MapboxMaps/Documentation.docc/API Catalogs/Style.md

@@ -23,6 +23,7 @@
 - ``StyleProjection``
 - ``StyleProjectionName``
 - ``CancelError``
+- ``TransitionOptions-struct``
 
 ### Style DSL
 

Sources/MapboxMaps/Documentation.docc/Extensions/MapboxMap.md

@@ -4,8 +4,8 @@
 
 ### Style loading
 
-- ``MapboxMap/loadStyle(_:transition:completion:)-2jmep``
-- ``MapboxMap/loadStyle(_:transition:completion:)-4vvrf``
+- ``MapboxMap/loadStyle(_:transition:completion:)-6icex``
+- ``MapboxMap/loadStyle(_:transition:completion:)-1ilz1``
 
 ### Map events
 

Sources/MapboxMaps/Foundation/Extensions/Core/TransitionOptions.swift

@@ -1,31 +1,58 @@
 import Foundation
-extension TransitionOptions {
+
+/**
+ * The `TransitionOptions` control timing for the interpolation between a transitionable style
+ * property's previous value and new value. These can be used to define the style default property
+ * transition behavior. Also, any transitionable style property may also have its own `-transition`
+ * property that defines specific transition timing for that specific layer property, overriding
+ * the global transition values.
+ */
+public struct TransitionOptions: Equatable {
     /// Initializes `TransitionOptions` with provided `duration`, `delay` and `enablePlacementTransitions` flag.
     /// - Parameters:
     ///   - duration: Time allotted for transitions to complete.
     ///   - delay: Length of time before the transition begins.
     ///   - enablePlacementTransitions: Whether the fade in/out symbol placement transition is enabled.
-    public convenience init(duration: TimeInterval?,
-                            delay: TimeInterval?,
-                            enablePlacementTransitions: Bool?) {
-
-        self.init(__duration: duration.map(NSNumber.init(value:)),
-                  delay: delay.map(NSNumber.init(value:)),
-                  enablePlacementTransitions: enablePlacementTransitions.map(NSNumber.init(value:)))
+    public init(duration: TimeInterval? = nil,
+                delay: TimeInterval? = nil,
+                enablePlacementTransitions: Bool? = nil) {
+        self.duration = duration
+        self.delay = delay
+        self.enablePlacementTransitions = enablePlacementTransitions
     }
 
     /// Time allotted for transitions to complete. Defaults to `0.3` seconds.
-    public var duration: TimeInterval? {
-        __duration?.doubleValue
-    }
+    public var duration: TimeInterval?
 
     /// Length of time before a transition begins. Defaults to `0.0` seconds.
-    public var delay: TimeInterval? {
-        __delay?.doubleValue
-    }
+    public var delay: TimeInterval?
 
     /// Whether the fade in/out symbol placement transition is enabled. Defaults to `true`.
-    public var enablePlacementTransitions: Bool? {
-        __enablePlacementTransitions?.boolValue
+    public var enablePlacementTransitions: Bool?
+
+    internal init(_ objValue: MapboxCoreMaps.TransitionOptions) {
+        self.init(duration: objValue.__duration?.doubleValue,
+                  delay: objValue.__delay?.doubleValue,
+                  enablePlacementTransitions: objValue.__enablePlacementTransitions?.boolValue)
+    }
+
+    internal var coreOptions: MapboxCoreMaps.TransitionOptions {
+        .init(self)
+    }
+}
+
+extension MapboxCoreMaps.TransitionOptions {
+    internal convenience init(_ swiftValue: TransitionOptions) {
+        self.init(__duration: swiftValue.duration.map(NSNumber.init(value:)),
+                  delay: swiftValue.delay.map(NSNumber.init(value:)),
+                  enablePlacementTransitions: swiftValue.enablePlacementTransitions.map(NSNumber.init(value:)))
+    }
+}
+
+@_spi(Experimental)
+@available(iOS 13.0, *)
+extension TransitionOptions: MapStyleContent, PrimitiveMapStyleContent {
+    func visit(_ node: MapStyleNode) {
+        node.mount(MountedUniqueProperty(keyPath: \.transition, value: self))
     }
 }

Sources/MapboxMaps/Foundation/MapboxMap.swift

@@ -1082,7 +1082,7 @@ extension MapboxMap {
     public var onStyleLoaded: Signal<StyleLoaded> { events.signal(for: \.onStyleLoaded) }
 
         /// The requested style data has been loaded. The `type` property defines what kind of style data has been loaded.
-        /// Event may be emitted synchronously, for example, when ``MapboxMap/loadStyle(_:transition:completion:)-2jmep`` is used to load style.
+        /// Event may be emitted synchronously, for example, when ``MapboxMap/loadStyle(_:transition:completion:)-1ilz1`` is used to load style.
         ///
         /// Based on an event data `type` property value, following use-cases may be implemented:
         /// - `style`: Style is parsed, style layer properties could be read and modified, style layers and sources could be

Sources/MapboxMaps/Snapshot/Snapshotter.swift

@@ -336,7 +336,7 @@ extension Snapshotter {
     public var onStyleLoaded: Signal<StyleLoaded> { events.signal(for: \.onStyleLoaded) }
 
     /// The requested style data has been loaded. The `type` property defines what kind of style data has been loaded.
-    /// Event may be emitted synchronously, for example, when ``MapboxMap/loadStyle(_:transition:completion:)-2jmep`` is used to load style.
+    /// Event may be emitted synchronously, for example, when ``MapboxMap/loadStyle(_:transition:completion:)-1ilz1`` is used to load style.
     ///
     /// Based on an event data `type` property value, following use-cases may be implemented:
     /// - `style`: Style is parsed, style layer properties could be read and modified, style layers and sources could be

Sources/MapboxMaps/Style/MapStyle/MapStyleReconciler.swift

@@ -45,11 +45,11 @@ final class MapStyleReconciler {
                     /// can continue loading.
                     /// We can safely add new content via style DSL.
                     guard let self else { return }
-                    if let transition {
-                        self.styleManager.setStyleTransitionFor(transition)
-                    }
                     self.reconcileStyleImports(from: oldMapStyle?.importConfigurations)
                     self._isStyleRootLoaded.value = true
+                    if let transition {
+                        self.styleManager.setStyleTransitionFor(transition.coreOptions)
+                    }
                 },
                 completed: { [weak self] in
                     completion?(nil)

Sources/MapboxMaps/Style/MapStyle/MapStyleUniqueProperties.swift

@@ -13,6 +13,7 @@ struct MapStyleUniqueProperties {
     var terrain: Terrain?
     var atmosphere: Atmosphere?
     var projection: StyleProjection?
+    var transition: TransitionOptions?
     var lights = Lights()
 
     private func update<T: Equatable & Encodable>(_ label: String, old: T?, new: T?, setter: (Any) -> Expected<NSNull, NSString>) {
@@ -37,20 +38,30 @@ struct MapStyleUniqueProperties {
         update("projection", old: old.projection, new: projection, setter: style.setStyleProjectionForProperties(_:))
         update("terrain", old: old.terrain, new: terrain, setter: style.setStyleTerrainForProperties(_:))
 
-        guard old.lights != lights else { return }
+        if old.lights != lights {
+            wrapStyleDSLError {
+                if let directional = lights.directional, let ambient = lights.ambient {
+                    os_log(.debug, log: .styleDsl, "set 3d lights")
+                    try style.setLights(ambient: ambient, directional: directional)
+                } else if lights.directional != nil || lights.ambient != nil {
+                    Log.warning(forMessage: "Incorrect 3D light configuration. Specify both directional and ambient lights.", category: "StyleDSL")
+                } else if let flat = lights.flat {
+                    os_log(.debug, log: .styleDsl, "set flat light")
+                    try style.setLights(flat)
+                } else {
+                    os_log(.debug, log: .styleDsl, "remove lights")
+                    try handleExpected { style.setStyleLightsForLights(NSNull()) }
+                }
+            }
+        }
 
-        wrapStyleDSLError {
-            if let directional = lights.directional, let ambient = lights.ambient {
-                os_log(.debug, log: .styleDsl, "set 3d lights")
-                try style.setLights(ambient: ambient, directional: directional)
-            } else if lights.directional != nil || lights.ambient != nil {
-                Log.warning(forMessage: "Incorrect 3D light configuration. Specify both directional and ambient lights.", category: "StyleDSL")
-            } else if let flat = lights.flat {
-                os_log(.debug, log: .styleDsl, "set flat light")
-                try style.setLights(flat)
-            } else {
-                os_log(.debug, log: .styleDsl, "remove lights")
-                try handleExpected { style.setStyleLightsForLights(NSNull()) }
+        if old.transition != transition {
+            wrapStyleDSLError {
+                if let transition {
+                    style.setStyleTransitionFor(transition.coreOptions)
+                } else {
+                    style.setStyleTransitionFor(TransitionOptions().coreOptions)
+                }
             }
         }
     }

Sources/MapboxMaps/Style/StyleManager.swift

@@ -554,10 +554,10 @@ public class StyleManager {
     /// - SeeAlso: ``MapboxMap/onNext(event:handler:)``
     public var styleTransition: TransitionOptions {
         get {
-            styleManager.getStyleTransition()
+            TransitionOptions(styleManager.getStyleTransition())
         }
         set {
-            styleManager.setStyleTransitionFor(newValue)
+            styleManager.setStyleTransitionFor(newValue.coreOptions)
         }
     }
 

Tests/MapboxMapsTests/Foundation/Extensions/Core/TransitionOptionsTests.swift

@@ -1,5 +1,5 @@
 import XCTest
-import MapboxMaps
+@testable import MapboxMaps
 
 final class TransitionOptionsTests: XCTestCase {
     func testInitWithNils() {
@@ -8,9 +8,9 @@ final class TransitionOptionsTests: XCTestCase {
             delay: nil,
             enablePlacementTransitions: nil)
 
-        XCTAssertNil(options.__duration)
-        XCTAssertNil(options.__delay)
-        XCTAssertNil(options.__enablePlacementTransitions)
+        XCTAssertNil(options.coreOptions.__duration)
+        XCTAssertNil(options.coreOptions.__delay)
+        XCTAssertNil(options.coreOptions.__enablePlacementTransitions)
     }
 
     func testInitWithNonNils() {
@@ -23,19 +23,18 @@ final class TransitionOptionsTests: XCTestCase {
             delay: delay,
             enablePlacementTransitions: enablePlacementTransition)
 
-        XCTAssertEqual(options.__duration, NSNumber(value: duration))
-        XCTAssertEqual(options.__delay, NSNumber(value: delay))
-        XCTAssertEqual(options.__enablePlacementTransitions, NSNumber(value: enablePlacementTransition))
+        XCTAssertEqual(options.coreOptions.__duration, NSNumber(value: duration))
+        XCTAssertEqual(options.coreOptions.__delay, NSNumber(value: delay))
+        XCTAssertEqual(options.coreOptions.__enablePlacementTransitions, NSNumber(value: enablePlacementTransition))
     }
 
     func testRefinedPropertiesWithNonNils() {
         let duration = TimeInterval.random(in: 0...10)
         let delay = TimeInterval.random(in: 0...10)
         let enablePlacementTransition = Bool.random()
-        let options = TransitionOptions(
-            __duration: NSNumber(value: duration),
-            delay: NSNumber(value: delay),
-            enablePlacementTransitions: NSNumber(value: enablePlacementTransition))
+        let options = TransitionOptions(duration: duration,
+                                        delay: delay,
+                                        enablePlacementTransitions: enablePlacementTransition)
 
         XCTAssertEqual(options.duration, duration)
         XCTAssertEqual(options.delay, delay)
@@ -44,12 +43,23 @@ final class TransitionOptionsTests: XCTestCase {
 
     func testRefinedPropertiesWithNils() {
         let options = TransitionOptions(
-            __duration: nil,
-            delay: nil,
-            enablePlacementTransitions: nil)
+                        duration: nil,
+                        delay: nil,
+                        enablePlacementTransitions: nil)
 
         XCTAssertNil(options.duration)
         XCTAssertNil(options.delay)
         XCTAssertNil(options.enablePlacementTransitions)
     }
+
+    func testTransitionOptionsEquality() {
+        let options = TransitionOptions(duration: 12, delay: 3, enablePlacementTransitions: true)
+        let options2 = TransitionOptions(duration: 12, delay: 3, enablePlacementTransitions: true)
+
+        XCTAssertEqual(options.duration, options2.duration)
+        XCTAssertEqual(options.delay, options2.delay)
+        XCTAssertEqual(options.enablePlacementTransitions, options2.enablePlacementTransitions)
+        XCTAssertEqual(options, options2)
+    }
+
 }

Tests/MapboxMapsTests/Foundation/Extensions/Turf/FeatureTests.swift

@@ -102,7 +102,7 @@ final class FeatureTests: XCTestCase {
     }
 
     func testSetPropertiesWithFunction() throws {
-        var feature = Feature(geometry: geometry)
+        let feature = Feature(geometry: geometry)
             .properties([
                 "a": 123,
                 "b": "c",

Tests/MapboxMapsTests/Foundation/Mocks/MockStyleManager.swift

@@ -49,7 +49,7 @@ class MockStyleManager: StyleManagerProtocol {
     }
 
     let getStyleTransitionStub = Stub<Void, MapboxCoreMaps.TransitionOptions>(
-        defaultReturnValue: TransitionOptions(duration: nil, delay: nil, enablePlacementTransitions: nil)
+        defaultReturnValue: .init(TransitionOptions())
     )
     func getStyleTransition() -> MapboxCoreMaps.TransitionOptions {
         getStyleTransitionStub.call()

Tests/MapboxMapsTests/Foundation/Style/MapStyleReconcilerTests.swift

@@ -162,7 +162,9 @@ final class MapStyleReconcilerTests: XCTestCase {
 
         XCTAssertEqual(styleManager.setStyleURIStub.invocations.count, 1)
         XCTAssertEqual(styleManager.setStyleTransitionStub.invocations.count, 1)
-        XCTAssertEqual(styleManager.setStyleTransitionStub.invocations.last?.parameters, transition)
+
+        let coreTransitionOptions = try XCTUnwrap(styleManager.setStyleTransitionStub.invocations.last?.parameters)
+        XCTAssertEqual(TransitionOptions(coreTransitionOptions), transition)
 
         XCTAssertEqual(calls, 2)
     }

Tests/MapboxMapsTests/Foundation/Style/StyleTests.swift

@@ -104,23 +104,24 @@ final class StyleManagerTests: XCTestCase {
     }
 
     func testGetStyleTransition() {
-        let stubTransition = MapboxCoreMaps.TransitionOptions(
+        let stubTransition = TransitionOptions(
             duration: .random(in: 0...300),
             delay: .random(in: 0...300),
             enablePlacementTransitions: .random())
-        styleManager.getStyleTransitionStub.defaultReturnValue = stubTransition
+        styleManager.getStyleTransitionStub.defaultReturnValue = stubTransition.coreOptions
 
         XCTAssertEqual(style.styleTransition, stubTransition)
     }
 
-    func testSetStyleTransition() {
-        let stubTransition = MapboxCoreMaps.TransitionOptions(
+    func testSetStyleTransition() throws {
+        let stubTransition = TransitionOptions(
             duration: .random(in: 0...300),
             delay: .random(in: 0...300),
             enablePlacementTransitions: .random())
         style.styleTransition = stubTransition
 
-        XCTAssertEqual(styleManager.setStyleTransitionStub.invocations.last?.parameters, stubTransition)
+        let coreTransitionOptions = try XCTUnwrap(styleManager.setStyleTransitionStub.invocations.last?.parameters)
+        XCTAssertEqual(TransitionOptions(coreTransitionOptions), stubTransition)
     }
 
     // MARK: Layer