Apply scene property expressions

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 // Copyright 2025 Esri // // Licensed under the Apache License, Version 2.0 (the "License"); // you may not use this file except in compliance with the License. // You may obtain a copy of the License at // // https://www.apache.org/licenses/LICENSE-2.0 // // Unless required by applicable law or agreed to in writing, software // distributed under the License is distributed on an "AS IS" BASIS, // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. // See the License for the specific language governing permissions and // limitations under the License.  import ArcGIS import SwiftUI  struct ApplyScenePropertyExpressionsView: View {  /// The scene that displays in the scene view.  @State private var scene: ArcGIS.Scene = {  let scene = Scene(basemapStyle: .arcGISImageryStandard)   // Give the scene an initial viewpoint.  let point = Point(x: 83.9, y: 28.4, z: 1000, spatialReference: .wgs84)  scene.initialViewpoint = Viewpoint(  latitude: .nan,  longitude: .nan,  scale: .nan,  camera: .init(lookingAt: point, distance: 1000, heading: 0, pitch: 50, roll: 0)  )   return scene  }()   /// The graphics overlay that we will display a cone graphic in.  @State private var graphicsOverlay = {  // Create a graphics overlay to hold our graphic.  let overlay = GraphicsOverlay()  overlay.sceneProperties.surfacePlacement = .relative   // Create a renderer for our graphics overlay and setup the heading  // and pitch expressions that will be used to adjust the heading  // and pitch of each graphic in the overlay. These expressions will  // be calculated based on the corresponding values in the graphic's  // attribute dictionary.  let renderer = SimpleRenderer()  renderer.sceneProperties.headingExpression = "[HEADING]"  renderer.sceneProperties.pitchExpression = "[PITCH]"  overlay.renderer = renderer   // Create a cone symbol.  let symbol = SimpleMarkerSceneSymbol.cone(  color: .red,  diameter: 100,  height: 100  )   // Create a graphic, setting initial heading and pitch in the  // attributes.  let graphic = Graphic(  geometry: Point(x: 83.9, y: 28.42, z: 200, spatialReference: .wgs84),  attributes: [  "HEADING": 180.0,  "PITCH": 45.0  ],  symbol: symbol  )   // Add the graphic to the overlay and return the overlay.  overlay.addGraphic(graphic)  return overlay  }()   /// A Boolean value indicating if the settings pane is displayed.  @State private var isSettingsPresented = false   /// The heading of the cone.  @State private var heading = 0.0   /// The pitch of the cone.  @State private var pitch = 0.0   /// The cone graphic.  private var coneGraphic: Graphic {  graphicsOverlay.graphics[0]  }   var body: some View {  SceneView(  scene: scene,  graphicsOverlays: [graphicsOverlay]  )  .toolbar {  ToolbarItem(placement: .bottomBar) {  Button("Settings") {  isSettingsPresented = true  }  .popover(isPresented: $isSettingsPresented) {  NavigationStack {  // The settings pane to adjust the symbology heading and pitch.  Form {  Section {  LabeledContent("Heading", value: heading, format: .number)  Slider(value: $heading, in: 0...360, step: 1) {  Text("Heading")  } minimumValueLabel: {  Text("0")  } maximumValueLabel: {  Text("360")  }  }  Section {  LabeledContent("Pitch", value: pitch, format: .number)  Slider(value: $pitch, in: 0...180, step: 1) {  Text("Pitch")  } minimumValueLabel: {  Text("0")  } maximumValueLabel: {  Text("180")  }  }  }  .toolbar {  ToolbarItem(placement: .confirmationAction) {  Button("Done") { isSettingsPresented = false }  }  }  .navigationTitle("Expression Settings")  .navigationBarTitleDisplayMode(.inline)  }  .presentationDetents([.medium])  .frame(idealWidth: 320, idealHeight: 380)  }  }  }  .onAppear {  // Sync view state with the graphic attributes on startup.  heading = coneGraphic.attributes["HEADING"] as? Double ?? 0  pitch = coneGraphic.attributes["PITCH"] as? Double ?? 0  }  // Sync view state with the graphic attributes on as it changes.  .onChange(of: heading) { coneGraphic.setAttributeValue(heading, forKey: "HEADING") }  .onChange(of: pitch) { coneGraphic.setAttributeValue(pitch, forKey: "PITCH") }  } }  #Preview {  ApplyScenePropertyExpressionsView() }