add setViewpointScale

android/src/main/java/com/valentingrigorean/arcgis_maps_flutter/map/ArcgisMapController.java

@@ -41,6 +41,7 @@
 import java.util.ArrayList;
 import java.util.List;
 import java.util.Map;
+import java.util.concurrent.ExecutionException;
 
 import io.flutter.plugin.common.BinaryMessenger;
 import io.flutter.plugin.common.MethodCall;
@@ -439,6 +440,25 @@ public void onMethodCall(@NonNull MethodCall call, @NonNull MethodChannel.Result
                 result.success(null);
                 break;
             }
+            case "map#setViewpointScaleAsync": {
+                final Map<?, ?> data = call.arguments();
+                if (mapView != null && data != null) {
+                    double scale = (double) data.get("scale");
+                    ListenableFuture<Boolean> future = mapView.setViewpointScaleAsync(scale);
+                    future.addDoneListener(() -> {
+                        boolean scaled = false;
+                        try {
+                            scaled = future.get();
+                            result.success(scaled);
+                        } catch (ExecutionException | InterruptedException e) {
+                            result.success(false);
+                        }
+                    });
+                } else {
+                    result.success(false);
+                }
+                break;
+            }
             default:
                 result.notImplemented();
                 break;

ios/Classes/Map/ArcgisMapController.swift

@@ -336,6 +336,16 @@ public class ArcgisMapController: NSObject, FlutterPlatformView {
             layersController.setTimeOffset(arguments: call.arguments)
             result(nil)
             break
+        case "map#setViewpointScaleAsync":
+            if let data = call.arguments as? Dictionary<String, Any> {
+                let scale = data["scale"] as! Double
+                mapView.setViewpointScale(scale, completion: { finished in
+                    result(finished)
+                })
+            } else {
+                result(false)
+            }
+            break
         default:
             result(FlutterMethodNotImplemented)
             break

lib/src/mapping/view/map/arcgis_map_controller.dart

@@ -131,6 +131,18 @@ class ArcgisMapController {
         .setViewpointRotation(mapId, angleDegrees);
   }
 
+  /// Asynchronously zooms the map, with animation, to the given scale.
+  /// The map center point does not change.
+  /// The map scale is the number of map units per unit of physical device size.
+  /// It expresses the relationship between a distance in the MapView and the corresponding distance on the ground.
+  /// A smaller value will zoom the map in and produce a larger map display area (features appear larger).
+  /// A larger value will zoom the map out and produce a smaller map display area (features appear smaller).
+  Future<bool> setViewpointScale(double scale) async {
+    assert(scale >= 0);
+    return await ArcgisMapsFlutterPlatform.instance
+        .setViewpointScale(mapId, scale);
+  }
+
   Future<Viewpoint?> getCurrentViewpoint(ViewpointType type) {
     return ArcgisMapsFlutterPlatform.instance.getCurrentViewpoint(mapId, type);
   }

lib/src/method_channel/map/arcgis_maps_flutter_platform.dart

@@ -135,6 +135,11 @@ abstract class ArcgisMapsFlutterPlatform extends PlatformInterface {
         'onViewpointChangedListener() has not been implemented.');
   }
 
+  Future<bool> setViewpointScale(int mapId, double scale) {
+    throw UnimplementedError(
+        'setViewpointScale() has not been implemented.');
+  }
+
   Future<Offset?> locationToScreen(int mapId, AGSPoint mapPoint) {
     throw UnimplementedError('locationToScreen() has not been implemented.');
   }

lib/src/method_channel/map/method_channel_arcgis_maps_flutter.dart

@@ -297,6 +297,16 @@ class MethodChannelArcgisMapsFlutter extends ArcgisMapsFlutterPlatform {
         .invokeMethod<void>("map#setViewpointRotation", angleDegrees);
   }
 
+  @override
+  Future<bool> setViewpointScale(int mapId, double scale) async{
+    final result = await channel(mapId).invokeMethod<bool>(
+      'map#setViewpointScaleAsync',
+      {
+        'scale': scale,
+      },
+    );
+    return result ?? false;
+  }
   @override
   Future<Offset?> locationToScreen(int mapId, AGSPoint mapPoint) async {
     final result = await channel(mapId)