Add custom dynamic entity data source

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 // 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 AddCustomDynamicEntityDataSourceView: View {  /// A map with an ArcGIS oceans basemap style and a dynamic entity layer.  @State private var map = makeMap()   /// The dynamic entity layer that is displaying our custom data.  private var dynamicEntityLayer: DynamicEntityLayer {  map.operationalLayers.first as! DynamicEntityLayer  }   /// The point on the screen the user tapped.  @State private var tappedScreenPoint: CGPoint?   /// The placement of the callout.  @State private var calloutPlacement: CalloutPlacement?   var body: some View {  MapViewReader { proxy in  MapView(map: map)  .onSingleTapGesture { screenPoint, _ in  tappedScreenPoint = screenPoint  }  .callout(placement: $calloutPlacement.animation(.default.speed(2))) { placement in  let attributes = (placement.geoElement as! DynamicEntityObservation).attributes  VStack(alignment: .leading) {  // Display all the attributes in the callout.  ForEach(attributes.sorted(by: { $0.key < $1.key }), id: \.key) { item in  Text("\(item.key): \(String(describing: item.value))")  }  }  }  .task(id: tappedScreenPoint) {  let newCalloutPlacement: CalloutPlacement?  if let tappedScreenPoint,  let identifyResult = try? await proxy.identify(  on: dynamicEntityLayer,  screenPoint: tappedScreenPoint,  tolerance: 2  ) {  // Set the callout placement to the observation that was tapped on.  newCalloutPlacement = identifyResult.geoElements.first.map { .geoElement($0) }  } else {  // Hides the callout.  newCalloutPlacement = nil  }  calloutPlacement = newCalloutPlacement  }  }  }   /// Makes a map with a dynamic entity layer.  private static func makeMap() -> Map {  let map = Map(basemapStyle: .arcGISOceans)  map.initialViewpoint = Viewpoint(  latitude: 47.984,  longitude: -123.657,  scale: 3e6  )   // The meta data for the custom dynamic entity data source.  let info = DynamicEntityDataSourceInfo(  entityIDFieldName: "MMSI",  fields: [  Field(type: .text, name: "MMSI", alias: "MMSI", length: 256),  Field(type: .float64, name: "SOG", alias: "SOG", length: 8),  Field(type: .float64, name: "COG", alias: "COG", length: 8),  Field(type: .text, name: "VesselName", alias: "VesselName", length: 256),  Field(type: .text, name: "CallSign", alias: "CallSign", length: 256)  ]  )   info.spatialReference = .wgs84   // Create our custom data source from our custom data feed.  let customDataSource = CustomDynamicEntityDataSource(info: info) { VesselFeed() }   let dynamicEntityLayer = DynamicEntityLayer(dataSource: customDataSource)   // Set display tracking properties on the layer.  let trackDisplayProperties = dynamicEntityLayer.trackDisplayProperties  trackDisplayProperties.showsPreviousObservations = true  trackDisplayProperties.showsTrackLine = true  trackDisplayProperties.maximumObservations = 20   // Create the label definition so we can show the vessel name on top of  // each dynamic entity.  let labelDefinition = LabelDefinition(  labelExpression: SimpleLabelExpression(simpleExpression: "[VesselName]"),  textSymbol: TextSymbol(color: .red, size: 12)  )  labelDefinition.placement = .pointAboveCenter   dynamicEntityLayer.addLabelDefinition(labelDefinition)  dynamicEntityLayer.labelsAreEnabled = true   map.addOperationalLayer(dynamicEntityLayer)   return map  } }  /// The vessel feed that is emitting custom dynamic entity events. private struct VesselFeed: CustomDynamicEntityFeed {  let events = URL.selectedVesselsDataSource.lines.map { line in  // Delay observations to simulate live data.  try await Task.sleep(nanoseconds: 10_000_000)   let decoder = JSONDecoder()  let vessel = try decoder.decode(  AddCustomDynamicEntityDataSourceView.Vessel.self,  from: line.data(using: .utf8)!  )   // The location of the vessel that was decoded from the JSON.  let location = vessel.geometry   // We successfully decoded the vessel JSON so we should  // add that vessel as a new observation.  return CustomDynamicEntityFeedEvent.newObservation(  geometry: Point(x: location.x, y: location.y, spatialReference: .wgs84),  attributes: vessel.attributes  )  } }  private extension URL {  /// The URL to the selected vessels JSON Lines data.  static var selectedVesselsDataSource: URL {  Bundle.main.url(  forResource: "AIS_MarineCadastre_SelectedVessels_CustomDataSource",  withExtension: "jsonl"  )!  } }