DictionaryRendererGraphicsOverlay.xaml.cs

// 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: http://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.

using ArcGIS.Samples.Managers;
using Esri.ArcGISRuntime.Geometry;
using Esri.ArcGISRuntime.Mapping;
using Esri.ArcGISRuntime.Symbology;
using Esri.ArcGISRuntime.UI;
using System.Globalization;
using System.Xml.Linq;

using PointCollection = Esri.ArcGISRuntime.Geometry.PointCollection;

namespace ArcGIS.Samples.DictionaryRendererGraphicsOverlay
{
    [ArcGIS.Samples.Shared.Attributes.Sample(
        name: "Dictionary renderer with graphics overlay",
        category: "GraphicsOverlay",
        description: "Create graphics from an XML file with key-value pairs for each graphic, and display the military symbols using a MIL-STD-2525D web style in 2D.",
        instructions: "Pan and zoom to explore military symbols on the map.",
        tags: new[] { "defense", "military", "situational awareness", "tactical", "visualization" })]
    [ArcGIS.Samples.Shared.Attributes.OfflineData("8776cfc26eed4485a03de6316826384c")]
    public partial class DictionaryRendererGraphicsOverlay : ContentPage
    {
        // Hold a reference to the graphics overlay for easy access.
        private GraphicsOverlay _tacticalMessageOverlay;

        public DictionaryRendererGraphicsOverlay()
        {
            InitializeComponent();
            _ = Initialize();
        }

        private async Task Initialize()
        {
            try
            {
                MyMapView.Map = new Map(BasemapStyle.ArcGISTopographic);

                // Create an overlay for visualizing tactical messages and add it to the map.
                _tacticalMessageOverlay = new GraphicsOverlay();
                MyMapView.GraphicsOverlays.Add(_tacticalMessageOverlay);

                // Prevent graphics from showing up when zoomed too far out.
                _tacticalMessageOverlay.MinScale = 1000000;

                // Create the dictionary symbol style from the Joint Military Symbology MIL-STD-2525D portal item.
                var symbolStyleUri = new Uri("https://www.arcgis.com/home/item.html?id=d815f3bdf6e6452bb8fd153b654c94ca");
                DictionarySymbolStyle dictionarySymbolStyle = await DictionarySymbolStyle.OpenAsync(symbolStyleUri);

                // Find the first configuration setting which has the property name "model", and set its value to "ORDERED ANCHOR POINTS".
                if (dictionarySymbolStyle?.Configurations?.FirstOrDefault(config => config.Name == "model") is DictionarySymbolStyleConfiguration configuration)
                {
                    configuration.Value = "ORDERED ANCHOR POINTS";
                }

                // Create a new dictionary renderer from the dictionary symbol style to render graphics with symbol dictionary attributes and set it to the graphics overlay renderer.
                _tacticalMessageOverlay.Renderer = new DictionaryRenderer(dictionarySymbolStyle);

                // Parse graphic attributes from an XML file following the mil2525d specification.
                LoadMilitaryMessages();

                // Get the extent of the graphics.
                Envelope graphicExtent = GeometryEngine.CombineExtents(_tacticalMessageOverlay.Graphics.Select(graphic => graphic.Geometry));

                // Zoom to the extent of the graphics.
                await MyMapView.SetViewpointGeometryAsync(graphicExtent, 10);
            }
            catch (Exception ex)
            {
                await Application.Current.MainPage.DisplayAlert(ex.GetType().Name, ex.Message, "OK");
            }
        }

        private void LoadMilitaryMessages()
        {
            // Get the path to the messages file.
            string militaryMessagePath = DataManager.GetDataFolder("8776cfc26eed4485a03de6316826384c", "Mil2525DMessages.xml");

            // Load the XML document.
            XElement xmlRoot = XElement.Load(militaryMessagePath);

            // Get all of the messages.
            IEnumerable<XElement> messages = xmlRoot.Descendants("message");

            // Add a graphic for each message.
            foreach (var message in messages)
            {
                Graphic messageGraphic = GraphicFromAttributes(message.Descendants().ToList());
                _tacticalMessageOverlay.Graphics.Add(messageGraphic);
            }
        }

        private Graphic GraphicFromAttributes(List<XElement> graphicAttributes)
        {
            // Get the geometry and the spatial reference from the message elements.
            XElement geometryAttribute = graphicAttributes.First(attr => attr.Name == "_control_points");
            XElement spatialReferenceAttr = graphicAttributes.First(attr => attr.Name == "_wkid");

            // Split the geometry field into a list of points.
            Array pointStrings = geometryAttribute.Value.Split(';');

            // Create a point collection in the correct spatial reference.
            int wkid = Convert.ToInt32(spatialReferenceAttr.Value);
            SpatialReference pointSR = SpatialReference.Create(wkid);
            PointCollection graphicPoints = new PointCollection(pointSR);

            // Add a point for each point in the list.
            foreach (string pointString in pointStrings)
            {
                var coords = pointString.Split(',');
                graphicPoints.Add(Convert.ToDouble(coords[0], CultureInfo.InvariantCulture), Convert.ToDouble(coords[1], CultureInfo.InvariantCulture));
            }

            // Create a multipoint from the point collection.
            Multipoint graphicMultipoint = new Multipoint(graphicPoints);

            // Create the graphic from the multipoint.
            Graphic messageGraphic = new Graphic(graphicMultipoint);

            // Add all of the message's attributes to the graphic (some of these are used for rendering).
            foreach (XElement attr in graphicAttributes)
            {
                messageGraphic.Attributes[attr.Name.ToString()] = attr.Value;
            }

            return messageGraphic;
        }
    }
}