private Task <bool> createFunnyGarden(Geometry geometry)
{
if (geometry == null)
{
return(Task.FromResult(false));
}
// get the point layer from the active map
var pointLayer = MapView.Active.Map.GetLayersAsFlattenedList().OfType <FeatureLayer>()
.Where(lyr => lyr.ShapeType == ArcGIS.Core.CIM.esriGeometryType.esriGeometryPoint).FirstOrDefault();
if (pointLayer == null)
{
return(Task.FromResult(false));
}
// get the polygon layer from the active map
var polygonLayer = MapView.Active.Map.GetLayersAsFlattenedList().OfType <FeatureLayer>()
.Where(lyr => lyr.ShapeType == ArcGIS.Core.CIM.esriGeometryType.esriGeometryPolygon).FirstOrDefault();
if (polygonLayer == null)
{
return(Task.FromResult(false));
}
// Create an edit operation
var createOperation = new EditOperation();
createOperation.Name = string.Format("Create green");
// we'll use the sketch geometry to create a spatial filter
SpatialQueryFilter spatialQueryFilter = new SpatialQueryFilter();
spatialQueryFilter.FilterGeometry = geometry;
spatialQueryFilter.SpatialRelationship = SpatialRelationship.Contains;
// retrieve the point features that are inside the sketch geometry
var searchCursor = pointLayer.Search(spatialQueryFilter);
// Construct a polygon placeholder for the point buffers
var treeBuffers = PolygonBuilder.CreatePolygon(geometry.SpatialReference);
// TODO
// 1. for each point geometry
// 2. buffer the geometry (Hint : use the MapView.Active.Extent.Width/50 as the buffer distance)
// 3. union this result with the existing treeBuffers
// 4. subtract the collection of buffers from the sketch geometry
// HINT: use the GeometryEngine to buffer, union and subtract (difference) the geometries
// Polygon greenGeometry = null;
// for each found feature
while (searchCursor.MoveNext())
{
// retrieve the geometry
var treeFeature = searchCursor.Current as Feature;
var treePoint = treeFeature.GetShape() as MapPoint;
// buffer the the location
var treeBuffer = GeometryEngine.Buffer(treePoint, MapView.Active.Extent.Width / 50);
// and union the new buffer to the existing buffer polygons
treeBuffers = GeometryEngine.Union(treeBuffer, treeBuffers) as Polygon;
}
// ensure the sketch geometry is simple
if (!GeometryEngine.IsSimpleAsFeature(geometry, true))
{
geometry = GeometryEngine.SimplifyAsFeature(geometry);
}
// construct the difference geometry between the sketch geometry and the buffered point polygons
var greenGeometry = GeometryEngine.Difference(geometry, treeBuffers);
// cue the create
createOperation.Create(polygonLayer, greenGeometry);
// execute the operation
return(createOperation.ExecuteAsync());
}