Add source code.

Author: CalebRas

Shared/Samples/Apply raster rendering rule/ApplyRasterRenderingRuleView.swift

@@ -16,10 +16,95 @@ import ArcGIS
 import SwiftUI
 
 struct ApplyRasterRenderingRuleView: View {
-    @State private var map = Map(basemapStyle: .arcGISTopographic)
+    /// A map with a streets basemap.
+    @State private var map = Map(basemapStyle: .arcGISStreets)
+    
+    /// An array of raster layers, each with a different rendering rule.
+    @State private var rasterLayers: [RasterLayer] = []
+    
+    /// The name of rendering rule selected by the picker.
+    @State private var selectedRenderingRule = "None"
+    
+    /// The viewpoint for zooming the map view to a layer's extent.
+    @State private var viewpoint: Viewpoint?
+    
+    /// The error shown in the error alert.
+    @State private var error: Error?
 
     var body: some View {
-        MapView(map: map)
+        MapView(map: map, viewpoint: viewpoint)
+            .toolbar {
+                ToolbarItem(placement: .bottomBar) {
+                    Picker("Rendering Rule", selection: $selectedRenderingRule) {
+                        ForEach(rasterLayers, id: \.name) { rasterLayer in
+                            Text(rasterLayer.name)
+                        }
+                    }
+                    .onChange(of: selectedRenderingRule) { newRule in
+                        if let rasterLayer = rasterLayers.first(where: { $0.name == newRule }) {
+                            setLayer(rasterLayer)
+                        }
+                    }
+                }
+            }
+            .task {
+                // Sets up the raster layers when the sample opens.
+                do {
+                    rasterLayers = try await makeRasterLayers()
+                    await rasterLayers.load()
+                    
+                    if let rasterLayer = rasterLayers.first {
+                        setLayer(rasterLayer)
+                    }
+                } catch {
+                    self.error = error
+                }
+            }
+            .errorAlert(presentingError: $error)
+    }
+    
+    /// Sets a given layer on the map and zooms the viewpoint the layer's extent.
+    /// - Parameter layer: The layer to set.
+    private func setLayer(_ layer: Layer) {
+        map.removeAllOperationalLayers()
+        map.addOperationalLayer(layer)
+        
+        if let layerExtent = layer.fullExtent {
+            viewpoint = Viewpoint(boundingGeometry: layerExtent)
+        }
+    }
+    
+    /// Creates raster layers for all the rendering rules from an image service raster.
+    /// - Returns: An array of new `RasterLayer` objects.
+    private func makeRasterLayers() async throws -> [RasterLayer] {
+        // Creates and loads an image service raster using an image service URL.
+        let imageServiceRaster = ImageServiceRaster(url: .charlotteLASImageService)
+        try await imageServiceRaster.load()
+        
+        // Gets the rendering rule infos from the raster's service info.
+        guard let renderingRuleInfos = imageServiceRaster.serviceInfo?.renderingRuleInfos else {
+            return []
+        }
+        
+        return renderingRuleInfos.map { renderingRuleInfo in
+            // Creates another image service raster and sets its rendering rule using the info.
+            // This is required since the raster can't be loaded when setting its rendering rule.
+            let imageServiceRaster = ImageServiceRaster(url: .charlotteLASImageService)
+            imageServiceRaster.renderingRule = RenderingRule(info: renderingRuleInfo)
+            
+            // Creates a layer using the raster.
+            let rasterLayer = RasterLayer(raster: imageServiceRaster)
+            rasterLayer.name = renderingRuleInfo.name
+            
+            return rasterLayer
+        }
+    }
+}
+
+private extension URL {
+    /// The web URL to the "CharlotteLAS" image service containing LAS files for Charlotte, NC downtown area.
+    static var charlotteLASImageService: URL {
+        URL(string: "https://sampleserver6.arcgisonline.com/arcgis/rest/services/CharlotteLAS/ImageServer")!
     }
 }