Change viewpoint

Change viewpoint


// Copyright 2016 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:
// 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 Android.App;
using Android.OS;
using Android.Views;
using Android.Widget;
using Esri.ArcGISRuntime.Geometry;
using Esri.ArcGISRuntime.Mapping;
using Esri.ArcGISRuntime.UI.Controls;
using System;
using System.Collections.Generic;
using System.Linq;

namespace ArcGISRuntime.Samples.ChangeViewpoint
        "Change viewpoint",
        "This sample demonstrates different ways in which you can change the viewpoint or visible area of the map.",
    public class ChangeViewpoint : Activity
        // Create and hold reference to the used MapView
        private MapView _myMapView = new MapView();

        // Coordinates for London
        private MapPoint LondonCoords = new MapPoint(
            -13881.7678417696, 6710726.57374296, SpatialReferences.WebMercator);
        private double LondonScale = 8762.7156655228955;

        // Coordinates for Redlands
        private Polygon RedlandsEnvelope = new Polygon(
            new List<MapPoint>
                    new MapPoint(-13049785.1566222, 4032064.6003424),
                    new MapPoint(-13049785.1566222, 4040202.42595729),
                    new MapPoint(-13037033.5780234, 4032064.6003424),
                    new MapPoint(-13037033.5780234, 4040202.42595729)

        // Coordinates for Edinburgh
        private Polygon EdinburghEnvelope = new Polygon(
            new List<MapPoint>
                new MapPoint(-354262.156621384, 7548092.94093301),
                new MapPoint(-354262.156621384, 7548901.50684376),
                new MapPoint(-353039.164455303, 7548092.94093301),
                new MapPoint(-353039.164455303, 7548901.50684376)},

        // String array to store titles for the viewpoints specified above.
        private string[] titles = new string[]
            "Center & Scale",

        protected override void OnCreate(Bundle bundle)

            Title = "Change viewpoint";

            // Create the UI, setup the control references and execute initialization 

        private void Initialize()
            // Create new Map with basemap and initial location
            Map myMap = new Map(Basemap.CreateTopographic());

            // Assign the map to the MapView
            _myMapView.Map = myMap;

        private void OnMapsClicked(object sender, EventArgs e)
            var viewpointsButton = sender as Button;

            // Create menu to show viewpoint options
            var mapsMenu = new PopupMenu(this, viewpointsButton);
            mapsMenu.MenuItemClick += OnViewpointMenuItemClicked;

            // Create menu options
            foreach (var title in titles)

            // Show menu in the view

        private async void OnViewpointMenuItemClicked(object sender, PopupMenu.MenuItemClickEventArgs e)
            // Get title from the selected item
            var selectedMapTitle = e.Item.TitleCondensedFormatted.ToString();

            switch (selectedMapTitle)
                case "Geometry":
                    // Set Viewpoint using Redlands envelope defined above and a padding of 20
                    await _myMapView.SetViewpointGeometryAsync(RedlandsEnvelope, 20);

                case "Center & Scale":
                    // Set Viewpoint so that it is centered on the London coordinates defined above
                    await _myMapView.SetViewpointCenterAsync(LondonCoords);
                    // Set the Viewpoint scale to match the specified scale 
                    await _myMapView.SetViewpointScaleAsync(LondonScale);

                case "Animate":
                    // Navigate to full extent of the first baselayer before animating to specified geometry
                    await _myMapView.SetViewpointAsync(
                        new Viewpoint(_myMapView.Map.Basemap.BaseLayers.First().FullExtent));
                    // Create a new Viewpoint using the specified geometry
                    var viewpoint = new Viewpoint(EdinburghEnvelope);
                    // Set Viewpoint of MapView to the Viewpoint created above and animate to it using a timespan of 5 seconds
                    await _myMapView.SetViewpointAsync(viewpoint, TimeSpan.FromSeconds(5));


        private void CreateLayout()
            // Create a new vertical layout for the app
            var layout = new LinearLayout(this) { Orientation = Orientation.Vertical };

            // Create button to show possible map options
            var mapsButton = new Button(this);
            mapsButton.Text = "Viewpoints";
            mapsButton.Click += OnMapsClicked;

            // Add maps button to the layout

            // Add the map view to the layout

            // Show the layout in the app

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