Add support for FillStyleLayer (#66)

* Add support for FillStyleLayer.

* linting

CHANGELOG.md

@@ -5,6 +5,10 @@ All notable changes to this project will be documented in this file.
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.1.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
+### Added
+
+- Added FillStyleLayer and example.
+
 ## Version 0.4.2 - 2024-12-03
 
 ### Fixed

Sources/MapLibreSwiftDSL/Style Layers/FillStyleLayer.swift

@@ -0,0 +1,81 @@
+import Foundation
+import InternalUtils
+import MapLibre
+import MapLibreSwiftMacros
+
+// TODO: Other properties and their modifiers
+@MLNStyleProperty<UIColor>("fillColor", supportsInterpolation: true)
+@MLNStyleProperty<UIColor>("fillOutlineColor", supportsInterpolation: true)
+@MLNStyleProperty<Float>("fillOpacity", supportsInterpolation: true)
+public struct FillStyleLayer: SourceBoundVectorStyleLayerDefinition {
+    public let identifier: String
+    public let sourceLayerIdentifier: String?
+    public var insertionPosition: LayerInsertionPosition = .aboveOthers
+    public var isVisible: Bool = true
+    public var maximumZoomLevel: Float? = nil
+    public var minimumZoomLevel: Float? = nil
+
+    public var source: StyleLayerSource
+    public var predicate: NSPredicate?
+
+    public init(identifier: String, source: Source) {
+        self.identifier = identifier
+        self.source = .source(source)
+        sourceLayerIdentifier = nil
+    }
+
+    public init(identifier: String, source: MLNSource, sourceLayerIdentifier: String? = nil) {
+        self.identifier = identifier
+        self.source = .mglSource(source)
+        self.sourceLayerIdentifier = sourceLayerIdentifier
+    }
+
+    public func makeStyleLayer(style: MLNStyle) -> StyleLayer {
+        let styleSource = addSource(to: style)
+
+        return FillStyleLayerInternal(definition: self, mglSource: styleSource)
+    }
+}
+
+private struct FillStyleLayerInternal: StyleLayer {
+    private var definition: FillStyleLayer
+    private let mglSource: MLNSource
+
+    public var identifier: String { definition.identifier }
+    public var insertionPosition: LayerInsertionPosition {
+        get { definition.insertionPosition }
+        set { definition.insertionPosition = newValue }
+    }
+
+    public var isVisible: Bool {
+        get { definition.isVisible }
+        set { definition.isVisible = newValue }
+    }
+
+    public var maximumZoomLevel: Float? {
+        get { definition.maximumZoomLevel }
+        set { definition.maximumZoomLevel = newValue }
+    }
+
+    public var minimumZoomLevel: Float? {
+        get { definition.minimumZoomLevel }
+        set { definition.minimumZoomLevel = newValue }
+    }
+
+    init(definition: FillStyleLayer, mglSource: MLNSource) {
+        self.definition = definition
+        self.mglSource = mglSource
+    }
+
+    public func makeMLNStyleLayer() -> MLNStyleLayer {
+        let result = MLNFillStyleLayer(identifier: identifier, source: mglSource)
+
+        result.fillColor = definition.fillColor
+        result.fillOutlineColor = definition.fillOutlineColor
+        result.fillOpacity = definition.fillOpacity
+
+        result.predicate = definition.predicate
+
+        return result
+    }
+}

Sources/MapLibreSwiftUI/Examples/FillStyleLayerPreviews.swift

@@ -0,0 +1,18 @@
+import MapLibre
+import MapLibreSwiftDSL
+import SwiftUI
+
+@available(iOS 17.0, *)
+#Preview {
+    @Previewable let source = ShapeSource(identifier: "fillSource") {
+        MLNPolygonFeature(coordinates: austriaPolygon, count: UInt(austriaPolygon.count))
+    }
+    MapView(styleURL: demoTilesURL, camera: .constant(.center(austriaPolygon.first!, zoom: 4))) {
+        FillStyleLayer(identifier: "fillLayer", source: source)
+            .fillColor(.red)
+            .fillOpacity(0.5)
+            .fillOutlineColor(.blue)
+    }
+
+    .ignoresSafeArea(.all)
+}

Sources/MapLibreSwiftUI/Examples/Preview Helpers.swift

@@ -3,3 +3,14 @@ import CoreLocation
 
 let switzerland = CLLocationCoordinate2D(latitude: 47.03041, longitude: 8.29470)
 public let demoTilesURL = URL(string: "https://demotiles.maplibre.org/style.json")!
+
+let austriaPolygon: [CLLocationCoordinate2D] = [
+    CLLocationCoordinate2D(latitude: 49.0200, longitude: 16.9600),
+    CLLocationCoordinate2D(latitude: 48.9000, longitude: 15.0160),
+    CLLocationCoordinate2D(latitude: 48.2890, longitude: 13.0310),
+    CLLocationCoordinate2D(latitude: 47.5237, longitude: 10.4350),
+    CLLocationCoordinate2D(latitude: 46.4000, longitude: 12.1500),
+    CLLocationCoordinate2D(latitude: 46.8700, longitude: 16.5900),
+    CLLocationCoordinate2D(latitude: 48.1234, longitude: 16.9600),
+    CLLocationCoordinate2D(latitude: 49.0200, longitude: 16.9600), // Closing point (same as start)
+]