Render multilayer symbols

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 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 // Copyright 2023 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 RenderMultilayerSymbolsView: View {  /// A map with a light gray basemap.  @State private var map: Map = {  let map = Map(basemapStyle: .arcGISLightGray)  map.initialViewpoint = Viewpoint(boundingGeometry: Point(x: -713_800, y: 0, spatialReference: .webMercator))  return map  }()   /// The graphics overlay containing the multilayer graphics and associated text graphics.  @State private var graphicsOverlay: GraphicsOverlay = {  let graphicsOverlay = GraphicsOverlay()   // Create graphics and add them to the graphics overlay.  graphicsOverlay.addGraphics(makeMultilayerPointSimpleMarkerGraphics())  graphicsOverlay.addGraphics(makeMultilayerPointPictureMarkerGraphics())  graphicsOverlay.addGraphics(makeMultilayerPolylineGraphics())  graphicsOverlay.addGraphics(makeMultilayerPolygonGraphics())  graphicsOverlay.addGraphics(makeComplexMultilayerSymbolGraphics())   return graphicsOverlay  }()   /// The offset used to keep a consistent distance between symbols in the same column.  private static let offsetBetweenSymbols = 20.0   var body: some View {  MapView(map: map, graphicsOverlays: [graphicsOverlay])  } }  private extension RenderMultilayerSymbolsView {  // MARK: Methods   /// Creates a text symbol with the text to be displayed on the map.  /// - Parameter text: The text used to create the text symbol.  /// - Returns: A new `TextSymbol` object.  private static func makeTextSymbol(text: String) -> TextSymbol {  // Create text symbol with a white background.  let textSymbol = TextSymbol(text: text, color: .black, size: 10)  textSymbol.backgroundColor = .white  return textSymbol  }   // MARK: MultilayerPoint Simple Markers   /// Creates the multilayer point simple marker graphics.  /// - Returns: The new `Graphic` objects to display on the map.  private static func makeMultilayerPointSimpleMarkerGraphics() -> [Graphic] {  // Create a text graphic.  var graphics = [  Graphic(  geometry: Point(x: -150, y: 50, spatialReference: .wgs84),  symbol: makeTextSymbol(text: "MultilayerPoint\nSimple Markers")  )  ]   // Create a red diamond graphic from JSON and a multilayer polygon symbol.  let redFillLayer = SolidFillSymbolLayer(color: .red)  let polygonSymbol = MultilayerPolygonSymbol(symbolLayers: [redFillLayer])  if let diamondGeometry = try? Geometry.fromJSON(.diamondGeometryJSON) {  graphics.append(makeGraphicWithVectorMarkerSymbolElement(  symbol: polygonSymbol,  geometry: diamondGeometry,  offset: 0  ))  }   // Create a triangle graphic from JSON and a multilayer polygon symbol.  if let triangleGeometry = try? Geometry.fromJSON(.triangleGeometryJSON) {  graphics.append(makeGraphicWithVectorMarkerSymbolElement(  symbol: polygonSymbol,  geometry: triangleGeometry,  offset: offsetBetweenSymbols  ))  }   // Create a cross graphic from JSON and a multilayer polyline symbol.  let redStrokeLayer = SolidStrokeSymbolLayer(width: 1, color: .red)  let polylineSymbol = MultilayerPolylineSymbol(symbolLayers: [redStrokeLayer])  if let crossGeometry = try? Geometry.fromJSON(.crossGeometryJSON) {  graphics.append(makeGraphicWithVectorMarkerSymbolElement(  symbol: polylineSymbol,  geometry: crossGeometry,  offset: offsetBetweenSymbols * 2  ))  }   return graphics  }   /// Creates a graphic of multilayer point symbol using a vector marker symbol element.  /// - Parameters:  /// - symbol: The symbol to create the graphic of.  /// - geometry: The geometry used to make the vector marker symbol element.  /// - offset: The offset used to keep a consistent distance between symbols in the same column.  /// - Returns: A new `Graphic` object of the multilayer point symbol.  private static func makeGraphicWithVectorMarkerSymbolElement(  symbol: MultilayerSymbol,  geometry: Geometry,  offset: Double  ) -> Graphic {  // Create a vector element using the passed symbol and geometry.  let vectorElement = VectorMarkerSymbolElement(geometry: geometry, multilayerSymbol: symbol)   // Create a vector layer using the vector element.  let vectorLayer = VectorMarkerSymbolLayer(vectorMarkerSymbolElements: [vectorElement])   // Create a point symbol using the vector layer.  let pointSymbol = MultilayerPointSymbol(symbolLayers: [vectorLayer])   // Create a graphic of the multilayer point symbol.  return Graphic(geometry: Point(x: -150, y: 20 - offset, spatialReference: .wgs84), symbol: pointSymbol)  }   // MARK: MultilayerPoint Picture Markers   /// Creates the multilayer point picture marker graphics .  /// - Returns: The new `Graphic` objects to display on the map.  private static func makeMultilayerPointPictureMarkerGraphics() -> [Graphic] {  // Create a text graphic.  var graphics = [  Graphic(  geometry: Point(x: -80, y: 50, spatialReference: .wgs84),  symbol: makeTextSymbol(text: "MultilayerPoint\nPicture Markers")  )  ]   // Create a campsite graphic using a URL.  let campsiteLayer = PictureMarkerSymbolLayer(url: .campsiteImage)  graphics.append(  makeGraphicFromPictureMarkerSymbol(layer: campsiteLayer, offset: 0)  )   // Create a pin graphic using an image in the project assets.  let pinLayer = PictureMarkerSymbolLayer(image: .pinBlueStar)  graphics.append(  makeGraphicFromPictureMarkerSymbol(layer: pinLayer, offset: 40)  )   return graphics  }   /// Creates a graphic from a picture marker symbol layer using a multilayer point symbol.  /// - Parameters:  /// - layer: The layer used to create the multilayer point symbol.  /// - offset: The offset used to keep a consistent distance between symbols in the same column.  /// - Returns: A new `Graphic` object of the multilayer point symbol.  private static func makeGraphicFromPictureMarkerSymbol(layer: PictureMarkerSymbolLayer, offset: Double) -> Graphic {  // Create a multilayer point symbol using the picture marker symbol layer.  layer.size = 40  let symbol = MultilayerPointSymbol(symbolLayers: [layer])   // Create the location for symbol using a point.  let symbolPoint = Point(x: -80, y: 20 - offset, spatialReference: .wgs84)   // Create the graphic for multilayer point symbol.  return Graphic(geometry: symbolPoint, symbol: symbol)  }   // MARK: Multilayer Polylines   /// Creates the multilayer polyline graphics.  /// - Returns: The new `Graphic` objects to display on the map.  private static func makeMultilayerPolylineGraphics() -> [Graphic] {  // Create a text graphic.  var graphics = [  Graphic(  geometry: Point(x: 0, y: 50, spatialReference: .wgs84),  symbol: makeTextSymbol(text: "Multilayer\nPolylines")  )  ]   // Create the polyline graphics.  graphics.append(contentsOf: [  // Dash, dot, dot.  makeMultilayerPolylineSymbolGraphic(dashSpacing: [4, 6, 0.5, 6, 0.5, 6], offset: 0),  // Dashes.  makeMultilayerPolylineSymbolGraphic(dashSpacing: [4, 6], offset: offsetBetweenSymbols),  // Dash, dot.  makeMultilayerPolylineSymbolGraphic(dashSpacing: [7, 9, 0.5, 9], offset: offsetBetweenSymbols * 2)  ])   return graphics  }   /// Creates a graphic of a dashed multilayer polyline symbol.  /// - Parameters:  /// - dashSpacing: The pattern of spaces and dashes used to create a dash effect.  /// - offset: The offset used to keep a consistent distance between symbols in the same column.  /// - Returns: A new `Graphic` object of the multilayer polyline symbol.  private static func makeMultilayerPolylineSymbolGraphic(dashSpacing: [Double], offset: Double) -> Graphic {  // Create a dash effect with the passed dash spacing.  let dashEffect = DashGeometricEffect(dashTemplate: dashSpacing)   // Create a solid stroke symbol layer for the line symbol.  let strokeLayer = SolidStrokeSymbolLayer(width: 3, color: .red, geometricEffects: [dashEffect])  strokeLayer.capStyle = .round   // Create a multilayer polyline symbol from the stroke layer.  let lineSymbol = MultilayerPolylineSymbol(symbolLayers: [strokeLayer])   // Create a polyline for the graphic.  let polyline = Polyline(  points: [  Point(x: -30, y: 20 - offset),  Point(x: 30, y: 20 - offset)  ],  spatialReference: .wgs84  )   // Create a graphic of the multilayer polyline symbol.  return Graphic(geometry: polyline, symbol: lineSymbol)  }   // MARK: Multilayer Polygons   /// Creates the multilayer polygon graphics.  /// - Returns: The new `Graphic` objects to display on the map.  private static func makeMultilayerPolygonGraphics() -> [Graphic] {  // Create a text graphic.  var graphics = [  Graphic(  geometry: Point(x: 65, y: 50, spatialReference: .wgs84),  symbol: makeTextSymbol(text: "Multilayer\nPolygons")  )  ]   // Create multilayer polygon symbols.  graphics.append(contentsOf: [  // Cross-hatched diagonal lines.  makeMultilayerPolygonSymbolGraphic(angles: [-45, 45], offset: 0),  // Hatched diagonal lines.  makeMultilayerPolygonSymbolGraphic(angles: [-45], offset: offsetBetweenSymbols),  // Hatched vertical lines.  makeMultilayerPolygonSymbolGraphic(angles: [90], offset: offsetBetweenSymbols * 2)  ])   return graphics  }   /// Creates a graphic of a multilayer polygon symbol.  /// - Parameters:  /// - angles: The angles at which to draw the fill lines within the polygon.  /// - offset: The offset used to keep a consistent distance between symbols in the same column.  /// - Returns: A new `Graphic` object of the multilayer polygon symbol.  private static func makeMultilayerPolygonSymbolGraphic(angles: [Double], offset: Double) -> Graphic {  // Create a stroke symbol layer to make the symbol layer.  let hatchStrokeLayer = SolidStrokeSymbolLayer(width: 2, color: .red)   // Create a list to hold all necessary symbol layers.  var symbolLayers: [SymbolLayer] = []   // For each angle, create a hatch fill symbol layer with hatched lines at the given angle.  for angle in angles {  let hatchLayer = HatchFillSymbolLayer(  polylineSymbol: MultilayerPolylineSymbol(symbolLayers: [hatchStrokeLayer]),  angle: angle  )   // Set separation distance for lines.  hatchLayer.separation = 9  symbolLayers.append(hatchLayer)  }   // Create a stroke symbol layer to be used as an outline.  let outlineStrokeLayer = SolidStrokeSymbolLayer(width: 1, color: .black)  symbolLayers.append(outlineStrokeLayer)   // Create a multilayer polygon symbol from the symbol layer list.  let polygonSymbol = MultilayerPolygonSymbol(symbolLayers: symbolLayers)   // Create rectangle polygon for the graphic.  let polygon = Polygon(  points: [  Point(x: 60, y: 25 - offset),  Point(x: 70, y: 25 - offset),  Point(x: 70, y: 20 - offset),  Point(x: 60, y: 20 - offset)  ],  spatialReference: .wgs84  )   // Create a graphic of the multilayer polygon symbol.  return Graphic(geometry: polygon, symbol: polygonSymbol)  }   // MARK: Complex Multilayer Symbols   /// Creates the complex multilayer symbol graphics.  /// - Returns: The new `Graphic` objects to display on the map.  private static func makeComplexMultilayerSymbolGraphics() -> [Graphic] {  // Create a text graphic.  var graphics = [  Graphic(  geometry: Point(x: 130, y: 50, spatialReference: .wgs84),  symbol: makeTextSymbol(text: "Complex Multilayer\nSymbols")  )  ]   // Create the complex multilayer graphics: a point, polygon and polyline.  if let complexPointGeometry = try? Geometry.fromJSON(.complexPointGeometryJSON) {  graphics.append(makeComplexPointGraphic(geometry: complexPointGeometry))  }  graphics.append(contentsOf: [  makeComplexPolygonGraphic(),  makeComplexPolylineGraphic()  ])   return graphics  }   /// Creates a graphic of a complex multilayer point from multiple symbol layers and given geometry.  /// - Parameter geometry: The geometry used to create a multilayer polygon symbol.  /// - Returns: A new `Graphic` object of the multilayer point symbol.  private static func makeComplexPointGraphic(geometry: Geometry) -> Graphic {  // Create the vector marker symbol layers for the complex point.  let orangeSquareLayer = makeLayerForComplexPoint(fillColor: .orange, outlineColor: .blue, size: 11)  orangeSquareLayer.anchor = SymbolAnchor(x: -4, y: -6, placementMode: .absolute)   let blackSquareLayer = makeLayerForComplexPoint(fillColor: .black, outlineColor: .cyan, size: 6)  blackSquareLayer.anchor = SymbolAnchor(x: 2, y: 1, placementMode: .absolute)   let purpleSquareLayer = makeLayerForComplexPoint(fillColor: .clear, outlineColor: .magenta, size: 14)  purpleSquareLayer.anchor = SymbolAnchor(x: 4, y: 2, placementMode: .absolute)   // Create a layer of a yellow hexagon with a black outline from the passed geometry.  let yellowFillLayer = SolidFillSymbolLayer(color: .yellow)  let blackOutline = SolidStrokeSymbolLayer(width: 2, color: .black)  let hexagonVectorElement = VectorMarkerSymbolElement(  geometry: geometry,  multilayerSymbol: MultilayerPolygonSymbol(symbolLayers: [yellowFillLayer, blackOutline])  )  let yellowHexagonLayer = VectorMarkerSymbolLayer(vectorMarkerSymbolElements: [hexagonVectorElement])  yellowHexagonLayer.size = 35   // Create the multilayer point symbol from the symbol layers.  let pointSymbol = MultilayerPointSymbol(symbolLayers: [  yellowHexagonLayer,  orangeSquareLayer,  blackSquareLayer,  purpleSquareLayer  ])   // Create a graphic of the multilayer point symbol.  return Graphic(geometry: Point(x: 130, y: 20, spatialReference: .wgs84), symbol: pointSymbol)  }   /// Creates a vector marker symbol layer for use in the composition of a complex point.  /// - Parameters:  /// - fillColor: The fill color of the symbol.  /// - outlineColor: The outline color of the symbol.  /// - size: The size of the symbol.  /// - Returns: A new `VectorMarkerSymbolLayer` object of the created symbol.  private static func makeLayerForComplexPoint(  fillColor: UIColor,  outlineColor: UIColor,  size: Double  ) -> VectorMarkerSymbolLayer {  // Create a fill layer and outline.  let fillLayer = SolidFillSymbolLayer(color: fillColor)  let outlineLayer = SolidStrokeSymbolLayer(width: 2, color: outlineColor)   // Create a geometry from an envelope.  let geometry = Envelope(  min: Point(x: -0.5, y: -0.5, spatialReference: .wgs84),  max: Point(x: 0.5, y: 0.5, spatialReference: .wgs84)  )   // Create a vector marker symbol element using the geometry and a multilayer polygon symbol.  let symbolElement = VectorMarkerSymbolElement(  geometry: geometry,  multilayerSymbol: MultilayerPolygonSymbol(symbolLayers: [fillLayer, outlineLayer])  )   // Create a symbol layer containing the symbol element.  let symbolLayer = VectorMarkerSymbolLayer(vectorMarkerSymbolElements: [symbolElement])  symbolLayer.size = size   return symbolLayer  }   /// Creates a graphic of a complex polygon made with multiple symbol layers.  /// - Returns: A new `Graphic` object of the multilayer polygon symbol.  private static func makeComplexPolygonGraphic() -> Graphic {  // Create a multilayer polygon symbol from the symbol layers.  let polygonSymbol = MultilayerPolygonSymbol(  symbolLayers: makeLayersForComplexMultilayerSymbols(includeRedFill: true)  )   // Create a polygon for the graphic.  let polygon = Polygon(  points: [  Point(x: 120, y: 0),  Point(x: 140, y: 0),  Point(x: 140, y: -10),  Point(x: 120, y: -10)  ],  spatialReference: .wgs84  )   // Create a graphic of the multilayer polygon symbol.  return Graphic(geometry: polygon, symbol: polygonSymbol)  }   /// Creates a graphic of the complex polyline made with multiple layers.  /// - Returns: A new `Graphic` object of the multilayer polyline symbol.  private static func makeComplexPolylineGraphic() -> Graphic {  // Create a multilayer polyline symbol from the symbol layers.  let polylineSymbol = MultilayerPolylineSymbol(  symbolLayers: makeLayersForComplexMultilayerSymbols(includeRedFill: false)  )   // Create a polyline geometry of the graphic.  let polyline = Polyline(  points: [  Point(x: 120, y: -25),  Point(x: 140, y: -25)  ],  spatialReference: .wgs84  )   // Create a graphic of the multilayer polygon symbol.  return Graphic(geometry: polyline, symbol: polylineSymbol)  }   /// Creates the symbol layers used to create the complex multilayer symbols.  /// - Parameter includeRedFill: A Boolean that indicates whether to include a red fill layer.  /// - Returns: The new `SymbolLayer` objects.  private static func makeLayersForComplexMultilayerSymbols(includeRedFill: Bool) -> [SymbolLayer] {  // Create a black dash effect.  let dashEffect = DashGeometricEffect(dashTemplate: [5, 3])  let blackDashesLayer = SolidStrokeSymbolLayer(width: 1, color: .black, geometricEffects: [dashEffect])  blackDashesLayer.capStyle = .square   // Create a black outline.  let blackOutlineLayer = SolidStrokeSymbolLayer(width: 7, color: .black)  blackOutlineLayer.capStyle = .round   // Create a yellow stroke.  let yellowStrokeLayer = SolidStrokeSymbolLayer(width: 5, color: .yellow)  yellowStrokeLayer.capStyle = .round   let symbolLayers = [blackOutlineLayer, yellowStrokeLayer, blackDashesLayer]  return includeRedFill ? symbolLayers + [SolidFillSymbolLayer(color: .red)] : symbolLayers  } }  private extension URL {  /// The URL to a campsite image on ArcGIS online.  static let campsiteImage = URL(  string: "https://static.arcgis.com/images/Symbols/OutdoorRecreation/Camping.png"  )! }  private extension Data {  /// The JSON for a complex point geometry.  static let complexPointGeometryJSON = Data("{\"rings\":[[[-2.89,5],[2.89,5],[5.77,0],[2.89,-5],[-2.89,-5],[-5.77,0],[-2.89,5]]]}".utf8)   /// The JSON for a diamond geometry.  static let diamondGeometryJSON = Data("{\"rings\":[[[0,2.5],[2.5,0],[0,-2.5],[-2.5,0],[0,2.5]]]}".utf8)   /// The JSON for a triangle geometry.  static let triangleGeometryJSON = Data("{\"rings\":[[[0,5],[5,-5],[-5,-5],[0,5]]]}".utf8)   /// The JSON for a cross geometry.  static let crossGeometryJSON = Data("{\"paths\":[[[-1,1],[0,0],[1,-1]],[[1,1],[0,0],[-1,-1]]]}".utf8) }  #Preview {  RenderMultilayerSymbolsView() }