Show result of spatial relationships

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 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 // Copyright 2022 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 ShowResultOfSpatialRelationshipsView: View {  /// The error shown in the error alert.  @State private var error: Error?   /// The point indicating where to identify a graphic.  @State private var identifyPoint: CGPoint?   /// The map point where the map was tapped.  @State private var mapPoint: Point?   /// A location callout placement.  @State private var calloutPlacement: CalloutPlacement?   /// The relationships for the selected graphic.  @State private var relationships: [Relationship] = []   /// The view model for the sample.  @StateObject private var model = Model()   /// Shows the relationships for the selected graphic.  /// - Parameter graphic: The graphic to show all spatial relationships for.  private func showRelationships(for graphic: Graphic) {  guard let selectedGeometry = graphic.geometry else {  return  }  // Updates the relationships.  relationships = model.allRelationships(for: selectedGeometry)  guard !relationships.isEmpty else {  return  }  // Updates the location callout placement.  calloutPlacement = mapPoint.map { CalloutPlacement.location($0) }  }   var body: some View {  MapViewReader { mapView in  MapView(map: model.map, graphicsOverlays: [model.graphicsOverlay])  .onSingleTapGesture { screenPoint, mapPoint in  identifyPoint = screenPoint  self.mapPoint = mapPoint  }  .callout(placement: $calloutPlacement.animation(.default.speed(2))) { _ in  VStack(alignment: .leading) {  ForEach(relationships, id: \.relationshipWithLabel) { relationship in  Text(relationship.relationshipWithLabel)  .font(.headline)  VStack(alignment: .leading) {  ForEach(relationship.spatialRelationships, id: \.self) { spatialRelationship in  Text(spatialRelationship)  }  }  .padding(.bottom, 5)  }  }  .padding(8)  }  .task(id: identifyPoint) {  guard let identifyPoint = identifyPoint else { return }  // Clears the selection.  model.graphicsOverlay.clearSelection()   if calloutPlacement == nil {  do {  // Identifies the graphic at the given screen point.  let results = try await mapView.identify(  on: model.graphicsOverlay,  screenPoint: identifyPoint,  tolerance: 12,  maximumResults: 1  )   if let identifiedGraphic = results.graphics.first {  // Selects the identified graphic.  model.graphicsOverlay.selectGraphics([identifiedGraphic])  // Shows the graphic's relationships.  showRelationships(for: identifiedGraphic)  }  } catch {  self.error = error  }  } else {  // Hides the callout.  calloutPlacement = nil  }  }  .overlay(alignment: .top) {  Text("Tap on the map to select the graphic.")  .frame(maxWidth: .infinity)  .padding(.vertical, 6)  .background(.thinMaterial, ignoresSafeAreaEdges: .horizontal)  }  .errorAlert(presentingError: $error)  }  } }  private extension ShowResultOfSpatialRelationshipsView {  /// The model used to store the geo model and other expensive objects  /// used in this view.  class Model: ObservableObject {  /// A map with a topographic basemap style and an initial viewpoint.  let map: Map = {  let map = Map(basemapStyle: .arcGISTopographic)  map.initialViewpoint = Viewpoint(center: Graphic.point.geometry as! Point, scale: 1e8)  return map  }()   /// A graphics overlay consisting of a polygon, polyline, and point.  let graphicsOverlay = GraphicsOverlay(graphics: [.polygon, .polyline, .point])   /// The polygon graphic.  private var polygonGraphic: Graphic { graphicsOverlay.graphics[0] }  /// The polyline graphic.  private var polylineGraphic: Graphic { graphicsOverlay.graphics[1] }  /// The point graphic.  private var pointGraphic: Graphic { graphicsOverlay.graphics[2] }   /// Returns the relevant spatial relationships for a given geometry with all other geometries in this sample.  /// - Parameter geometry: The geometry to find all spatial relationships for.  /// - Returns: An array of relationships between the given geometry and all other geometries.  func allRelationships(for geometry: Geometry) -> [Relationship] {  let pointGeometry = pointGraphic.geometry!  let polylineGeometry = polylineGraphic.geometry!  let polygonGeometry = polygonGraphic.geometry!   switch geometry {  case is Point:  return [  Relationship(between: pointGeometry, and: polylineGeometry),  Relationship(between: pointGeometry, and: polygonGeometry)  ]  case is Polyline:  return [  Relationship(between: polylineGeometry, and: pointGeometry),  Relationship(between: polylineGeometry, and: polygonGeometry)  ]  case is ArcGIS.Polygon:  return [  Relationship(between: polygonGeometry, and: pointGeometry),  Relationship(between: polygonGeometry, and: polylineGeometry)  ]  default:  return []  }  }  } }  private extension ShowResultOfSpatialRelationshipsView {  /// The relationship between one geometry and another geometry.  struct Relationship {  /// The input geometry to be compared.  private let geometryOne: Geometry  /// The input geometry to be compared against.  private let geometryTwo: Geometry   /// - Parameters:  /// - geometryOne: The input geometry to be compared.  /// - geometryTwo: The input geometry to be compared against.  init(between geometryOne: Geometry, and geometryTwo: Geometry) {  self.geometryOne = geometryOne  self.geometryTwo = geometryTwo  }   /// The spatial relationships between geometry one and two.  var spatialRelationships: [String] {  geometryOne.getSpatialRelationships(with: geometryTwo)  }   /// A description of what geometry type `geometryOne` is compared against.  var relationshipWithLabel: String {  "Relationship with \(geometryTwo.type)"  }  } }  private extension Geometry {  /// Checks the different relationships between two geometries and returns the result as an array of strings.  /// - Parameter geometry: The input geometry to be compared against.  /// - Returns: An array of strings representing a relationship.  func getSpatialRelationships(with geometry: Geometry) -> [String] {  var relationships: [String] = []  if GeometryEngine.isGeometry(self, crossing: geometry) {  relationships.append("Crosses")  }  if GeometryEngine.doesGeometry(self, contain: geometry) {  relationships.append("Contains")  }  if GeometryEngine.isGeometry(self, disjointWith: geometry) {  relationships.append("Disjoint")  }  if GeometryEngine.isGeometry(self, intersecting: geometry) {  relationships.append("Intersects")  }  if GeometryEngine.isGeometry(self, overlapping: geometry) {  relationships.append("Overlaps")  }  if GeometryEngine.isGeometry(self, touching: geometry) {  relationships.append("Touches")  }  if GeometryEngine.isGeometry(self, within: geometry) {  relationships.append("Within")  }  return relationships  }   /// The type of the geometry.  var type: String {  switch self {  case is Point: return "Point"  case is Polyline: return "Polyline"  case is ArcGIS.Polygon: return "Polygon"  default: return "Unknown"  }  } }  private extension Graphic {  /// A green polygon with a forward diagonal style.  static var polygon: Graphic {  let polygon = Polygon(  points: [  Point(x: -5991501.677830, y: 5599295.131468),  Point(x: -6928550.398185, y: 2087936.739807),  Point(x: -3149463.800709, y: 1840803.011362),  Point(x: -1563689.043184, y: 3714900.452072),  Point(x: -3180355.516764, y: 5619889.608838)  ],  spatialReference: .webMercator  )  let lineSymbol = SimpleLineSymbol(style: .solid, color: .green, width: 2)  let fillSymbol = SimpleFillSymbol(style: .forwardDiagonal, color: .green, outline: lineSymbol)  return Graphic(geometry: polygon, symbol: fillSymbol)  }   /// A red, dashed polyline.  static var polyline: Graphic {  let polyline = Polyline(  points: [  Point(x: -4354240.726880, y: -609939.795721),  Point(x: -3427489.245210, y: 2139422.933233),  Point(x: -2109442.693501, y: 4301843.057130),  Point(x: -1810822.771630, y: 7205664.366363)  ],  spatialReference: .webMercator  )  let lineSymbol = SimpleLineSymbol(style: .dash, color: .red, width: 4)  return Graphic(geometry: polyline, symbol: lineSymbol)  }   /// A blue point.  static var point: Graphic {  let point = Point(x: -4487263.495911, y: 3699176.480377, spatialReference: .webMercator)  let markerSymbol = SimpleMarkerSymbol(color: .blue, size: 10)  return Graphic(geometry: point, symbol: markerSymbol)  } }  #Preview {  ShowResultOfSpatialRelationshipsView() }