Make root properties revertible for all styles (#2162)

CHANGELOG.md

@@ -7,6 +7,8 @@ Mapbox welcomes participation and contributions from everyone.
 
 * Expose `clusterMinPoints` property for `GeoJSONSource` and for `ClusterOptions`
 
+* Root properties (`Atmosphere`, `Lights`, `Projection`, `Terrain`, `Transition`) are now revertible for all styles. 
+
 ## 11.4.0 - 22 May, 2024
 
 * Live performance metrics collection. Mapbox Maps SDK v11.4.0 collects certain performance and feature usage counters so we can better benchmark the MapboxMaps library and invest in its performance. The performance counters have been carefully designed so that user-level metrics and identifiers are not collected.

Sources/MapboxMaps/ContentBuilders/MapContent/MapContentUniqueProperties.swift

@@ -3,7 +3,7 @@ import os
 
 /// The style properties that can be applied once in the whole style.
 /// If multiple properties are applied, the last wins.
-struct MapContentUniqueProperties {
+struct MapContentUniqueProperties: Decodable {
     struct Lights: Encodable, Equatable {
         var flat: FlatLight?
         var directional: DirectionalLight?
@@ -17,48 +17,79 @@ struct MapContentUniqueProperties {
     var location: LocationOptions?
     var lights = Lights()
 
-    private func update<T: Equatable & Encodable>(_ label: String, old: T?, new: T?, setter: (Any) -> Expected<NSNull, NSString>) {
+    private func update<T: Equatable & Encodable>(_ label: String, old: T?, new: T?, initial: T?, setter: (Any) -> Expected<NSNull, NSString>) {
         guard old != new else { return }
         wrapStyleDSLError {
             let value: Any
             if let new {
                 os_log(.debug, log: .contentDSL, "set %s", label)
                 value = try new.toJSON()
             } else {
-                os_log(.debug, log: .contentDSL, "remove %s", label)
-                value = NSNull()
+                os_log(.debug, log: .contentDSL, "set back to initial %s", label)
+                value = try initial.toJSON()
             }
             try handleExpected {
                 setter(value)
             }
         }
     }
 
-    func update(from old: Self, style: StyleManagerProtocol, locationManager: LocationManager?) {
-        update("atmosphere", old: old.atmosphere, new: atmosphere, setter: style.setStyleAtmosphereForProperties(_:))
-        update("projection", old: old.projection, new: projection, setter: style.setStyleProjectionForProperties(_:))
-        update("terrain", old: old.terrain, new: terrain, setter: style.setStyleTerrainForProperties(_:))
+    func update(from old: Self, style: StyleManagerProtocol, initial: Self?, locationManager: LocationManager?) {
+        update("atmosphere", old: old.atmosphere, new: atmosphere, initial: initial?.atmosphere, setter: style.setStyleAtmosphereForProperties(_:))
+        update("projection", old: old.projection, new: projection, initial: initial?.projection, setter: style.setStyleProjectionForProperties(_:))
+        update("terrain", old: old.terrain, new: terrain, initial: initial?.terrain, setter: style.setStyleTerrainForProperties(_:))
 
-        lights.update(from: old.lights, style: style)
+        lights.update(from: old.lights, style: style, initialLights: initial?.lights)
 
         if old.location != location {
             locationManager?.options = location ?? LocationOptions()
         }
 
         if old.transition != transition {
             wrapStyleDSLError {
-                if let transition {
-                    style.setStyleTransitionFor(transition.coreOptions)
-                } else {
-                    style.setStyleTransitionFor(TransitionOptions().coreOptions)
+                let transitionToSet: TransitionOptions = transition ?? initial?.transition ?? TransitionOptions()
+                style.setStyleTransitionFor(transitionToSet.coreOptions)
+            }
+        }
+    }
+}
+
+extension MapContentUniqueProperties {
+    enum CodingKeys: String, CodingKey {
+        case terrain
+        case atmosphere = "fog"
+        case projection
+        case lights = "lights"
+    }
+
+    /// Decode  from a StyleJSON
+    init(from decoder: any Decoder) throws {
+        let container = try decoder.container(keyedBy: CodingKeys.self)
+        self.terrain = try container.decodeIfPresent(Terrain.self, forKey: .terrain)
+        self.atmosphere = try container.decodeIfPresent(Atmosphere.self, forKey: .atmosphere)
+        self.projection = try container.decodeIfPresent(StyleProjection.self, forKey: .projection)
+        if var lightContainer = try? container.nestedUnkeyedContainer(forKey: .lights) {
+            while !lightContainer.isAtEnd {
+                var lightInfoContainer = lightContainer
+                let lightInfo = try lightInfoContainer.decode(LightInfo.self)
+
+                switch lightInfo.type {
+                case .ambient:
+                    lights.ambient = try? lightContainer.decode(AmbientLight.self)
+                case .directional:
+                    lights.directional = try? lightContainer.decode(DirectionalLight.self)
+                case .flat:
+                    lights.flat = try? lightContainer.decode(FlatLight.self)
+                default:
+                    Log.warning(forMessage: "Incorrect light configuration. Specify both directional and ambient lights OR flat light.", category: "StyleDSL")
                 }
             }
         }
     }
 }
 
 private extension MapContentUniqueProperties.Lights {
-    func update(from old: Self, style: StyleManagerProtocol) {
+    func update(from old: Self, style: StyleManagerProtocol, initialLights: Self?) {
         if self != old {
             wrapStyleDSLError {
                 if let directional = directional, let ambient = ambient {
@@ -70,10 +101,24 @@ private extension MapContentUniqueProperties.Lights {
                     os_log(.debug, log: .contentDSL, "set flat light")
                     try style.setLights(flat)
                 } else {
-                    os_log(.debug, log: .contentDSL, "remove lights")
-                    try handleExpected { style.setStyleLightsForLights(NSNull()) }
+                    os_log(.debug, log: .contentDSL, "set initial lights")
+                    try setInitialLights(style: style, initialLights: initialLights)
                 }
             }
         }
     }
+
+    func setInitialLights(style: StyleManagerProtocol, initialLights: Self?) throws {
+        if let initialDirectional = initialLights?.directional,
+           let initialAmbient = initialLights?.ambient {
+            os_log(.debug, log: .contentDSL, "re-set initial 3d lights")
+            try style.setLights(ambient: initialAmbient, directional: initialDirectional)
+        } else if let initialFlat = initialLights?.flat {
+            os_log(.debug, log: .contentDSL, "re-set initial flat lights")
+            try style.setLights(initialFlat)
+        } else {
+            os_log(.debug, log: .contentDSL, "remove lights")
+            try handleExpected { style.setStyleLightsForLights(NSNull()) }
+        }
+    }
 }

Sources/MapboxMaps/ContentBuilders/Tree/MapContentNodeContext.swift

@@ -24,6 +24,7 @@ final class MapContentNodeContext {
 
     var lastImportId: String?
     var initialStyleImports: [String] = []
+    var initialUniqueProperties: MapContentUniqueProperties?
 
     var uniqueProperties = MapContentUniqueProperties()
 

Sources/MapboxMaps/ContentBuilders/Tree/MapContentReconciler.swift

@@ -77,6 +77,7 @@ private extension MapContentNodeContext {
         uniqueProperties.update(
             from: oldProperties,
             style: style.styleManager,
+            initial: initialUniqueProperties,
             locationManager: content?.location.value
         )
     }
@@ -85,21 +86,39 @@ private extension MapContentNodeContext {
         lastLayerId = nil
 
         /// On style reload we need to traverse the whole tree to reconstruct non-persistent layers
-        /// On style we need to identifty bottom position in the style in order to stack content above
+        /// On style reload we need to identify the bottom position in the style in order to stack content above
         /// Position must take into account only non-persistent layers, which was not added in runtime
         isEqualContent = { _, _ in false }
         initialStyleLayers = getInitialStyleLayers() ?? []
         initialStyleImports = style.styleManager.getStyleImports().map(\.id)
+        initialUniqueProperties = getInitialUniqueProperties()
+
         mapContent.update(root)
         isEqualContent = arePropertiesEqual
 
         uniqueProperties.update(
             from: MapContentUniqueProperties(),
             style: style.styleManager,
+            initial: initialUniqueProperties,
             locationManager: content?.location.value
         )
     }
 
+    func getInitialUniqueProperties() -> MapContentUniqueProperties? {
+        if let jsonData = style.styleManager.getStyleJSON().data(using: .utf8) {
+            do {
+                var initialMapUniqueProperties = try JSONDecoder().decode(MapContentUniqueProperties.self, from: jsonData)
+                // Transition options are not included in the StyleJSON
+                initialMapUniqueProperties.transition = TransitionOptions(style.styleManager.getStyleTransition())
+                return initialMapUniqueProperties
+            } catch {
+                Log.warning(forMessage: "Unable to decode initial MapContentUniqueProperties \(error) from StyleJSON", category: "StyleDSL")
+                return nil
+            }
+        }
+        return nil
+    }
+
     func getInitialStyleLayers() -> [String]? {
         try? style.styleManager
             .getStyleLayers()

Sources/MapboxMaps/Style/LightInfo.swift

@@ -1,7 +1,7 @@
 import Foundation
 
 /// Information about a light
-public struct LightInfo {
+public struct LightInfo: Decodable {
     /// The identifier of the light
     public var id: String