Add graphics with symbols

<?xml version="1.0" encoding="utf-8" ?>
<ContentPage x:Class="ArcGIS.Samples.AddGraphicsWithSymbols.AddGraphicsWithSymbols"
             xmlns="http://schemas.microsoft.com/dotnet/2021/maui"
             xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
             xmlns:esriUI="clr-namespace:Esri.ArcGISRuntime.Maui;assembly=Esri.ArcGISRuntime.Maui">
    <Grid>
        <esriUI:MapView x:Name="MyMapView" />
    </Grid>
</ContentPage>

// 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 Esri.ArcGISRuntime.Geometry;
using Esri.ArcGISRuntime.Mapping;
using Esri.ArcGISRuntime.Symbology;
using Esri.ArcGISRuntime.UI;

using Colors = System.Drawing.Color;
using PointCollection = Esri.ArcGISRuntime.Geometry.PointCollection;

namespace ArcGIS.Samples.AddGraphicsWithSymbols
{
    [ArcGIS.Samples.Shared.Attributes.Sample(
        name: "Add graphics with symbols",
        category: "GraphicsOverlay",
        description: "Use a symbol style to display a graphic on a graphics overlay.",
        instructions: "Observe the graphics on the map.",
        tags: new[] { "display", "fill", "graphics", "line", "marker", "overlay", "point", "symbol" })]
    public partial class AddGraphicsWithSymbols : ContentPage
    {
        // Create the graphics overlay.
        private readonly GraphicsOverlay _overlay = new GraphicsOverlay();

        public AddGraphicsWithSymbols()
        {
            InitializeComponent();

            // Create the UI, setup the control references and execute initialization.
            Initialize();
        }

        private void Initialize()
        {
            // Create the map.
            Map myMap = new Map(BasemapStyle.ArcGISOceans);
            myMap.InitialViewpoint = new Viewpoint(56.075844, -2.681572, 13);

            // Add the map to the map view.
            MyMapView.Map = myMap;

            // Add the graphics overlay to the map view.
            MyMapView.GraphicsOverlays.Add(_overlay);

            // Call functions to create the graphics.
            CreatePoints();
            CreatePolygon();
            CreatePolyline();
            CreateText();

            // Update the extent to encompass all of the symbols.
            SetExtent();
        }

        private void CreatePoints()
        {
            // Create a red circle simple marker symbol.
            SimpleMarkerSymbol redCircleSymbol = new SimpleMarkerSymbol(SimpleMarkerSymbolStyle.Circle, Colors.Red, 10);

            // Create graphics and add them to graphics overlay.
            Graphic graphic = new Graphic(new MapPoint(-2.72, 56.065, SpatialReferences.Wgs84), redCircleSymbol);
            _overlay.Graphics.Add(graphic);

            graphic = new Graphic(new MapPoint(-2.69, 56.065, SpatialReferences.Wgs84), redCircleSymbol);
            _overlay.Graphics.Add(graphic);

            graphic = new Graphic(new MapPoint(-2.66, 56.065, SpatialReferences.Wgs84), redCircleSymbol);
            _overlay.Graphics.Add(graphic);

            graphic = new Graphic(new MapPoint(-2.63, 56.065, SpatialReferences.Wgs84), redCircleSymbol);
            _overlay.Graphics.Add(graphic);
        }

        private void CreatePolyline()
        {
            // Create a purple simple line symbol.
            SimpleLineSymbol lineSymbol = new SimpleLineSymbol(SimpleLineSymbolStyle.Dash, Colors.Purple, 4);

            // Create a new point collection for polyline.
            PointCollection points = new PointCollection(SpatialReferences.Wgs84)
            {
                // Create and add points to the point collection.
                new MapPoint(-2.715, 56.061),
                new MapPoint(-2.6438, 56.079),
                new MapPoint(-2.638, 56.079),
                new MapPoint(-2.636, 56.078),
                new MapPoint(-2.636, 56.077),
                new MapPoint(-2.637, 56.076),
                new MapPoint(-2.715, 56.061)
            };

            // Create the polyline from the point collection.
            Polyline polyline = new Polyline(points);

            // Create the graphic with polyline and symbol.
            Graphic graphic = new Graphic(polyline, lineSymbol);

            // Add graphic to the graphics overlay.
            _overlay.Graphics.Add(graphic);
        }

        private void CreatePolygon()
        {
            // Create a green simple line symbol.
            SimpleLineSymbol outlineSymbol = new SimpleLineSymbol(SimpleLineSymbolStyle.Dash, Colors.Green, 1);

            // Create a green mesh simple fill symbol.
            SimpleFillSymbol fillSymbol = new SimpleFillSymbol(SimpleFillSymbolStyle.DiagonalCross, Colors.Green, outlineSymbol);

            // Create a new point collection for polygon.
            PointCollection points = new PointCollection(SpatialReferences.Wgs84)
            {
                // Create and add points to the point collection.
                new MapPoint(-2.6425, 56.0784),
                new MapPoint(-2.6430, 56.0763),
                new MapPoint(-2.6410, 56.0759),
                new MapPoint(-2.6380, 56.0765),
                new MapPoint(-2.6380, 56.0784),
                new MapPoint(-2.6410, 56.0786)
            };

            // Create the polyline from the point collection.
            Polygon polygon = new Polygon(points);

            // Create the graphic with polyline and symbol.
            Graphic graphic = new Graphic(polygon, fillSymbol);

            // Add graphic to the graphics overlay.
            _overlay.Graphics.Add(graphic);
        }

        private void CreateText()
        {
            // Create two text symbols.
            TextSymbol bassRockTextSymbol = new TextSymbol("Black Rock", Colors.Blue, 10,
                Esri.ArcGISRuntime.Symbology.HorizontalAlignment.Left, Esri.ArcGISRuntime.Symbology.VerticalAlignment.Bottom);

            TextSymbol craigleithTextSymbol = new TextSymbol("Craigleith", Colors.Blue, 10,
                Esri.ArcGISRuntime.Symbology.HorizontalAlignment.Right, Esri.ArcGISRuntime.Symbology.VerticalAlignment.Top);

            // Create two points.
            MapPoint bassPoint = new MapPoint(-2.64, 56.079, SpatialReferences.Wgs84);
            MapPoint craigleithPoint = new MapPoint(-2.72, 56.076, SpatialReferences.Wgs84);

            // Create two graphics from the points and symbols.
            Graphic bassRockGraphic = new Graphic(bassPoint, bassRockTextSymbol);
            Graphic craigleithGraphic = new Graphic(craigleithPoint, craigleithTextSymbol);

            // Add graphics to the graphics overlay.
            _overlay.Graphics.Add(bassRockGraphic);
            _overlay.Graphics.Add(craigleithGraphic);
        }

        private void SetExtent()
        {
            // Get all of the graphics contained in the graphics overlay.
            GraphicCollection myGraphicCollection = _overlay.Graphics;

            // Create a new envelope builder using the same spatial reference as the graphics.
            EnvelopeBuilder myEnvelopeBuilder = new EnvelopeBuilder(SpatialReferences.Wgs84);

            // Loop through each graphic in the graphic collection.
            foreach (Graphic oneGraphic in myGraphicCollection)
            {
                // Union the extent of each graphic in the envelope builder.
                myEnvelopeBuilder.UnionOf(oneGraphic.Geometry.Extent);
            }

            // Expand the envelope builder by 30%.
            myEnvelopeBuilder.Expand(1.3);

            // Adjust the viewable area of the map to encompass all of the graphics in the
            // graphics overlay plus an extra 30% margin for better viewing.
            MyMapView.SetViewpointAsync(new Viewpoint(myEnvelopeBuilder.Extent));
        }
    }
}