AuthorMap.xaml.cs

// 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: 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.Portal;
using Esri.ArcGISRuntime.Security;
using Esri.ArcGISRuntime.UI;
using System;
using System.Collections.Generic;
using System.IO;
using System.Threading.Tasks;
using Windows.UI.Popups;
using Windows.UI.Xaml;
using Windows.UI.Xaml.Controls;

namespace ArcGISRuntime.UWP.Samples.AuthorMap
{
    [ArcGISRuntime.Samples.Shared.Attributes.Sample(
        "Author a map",
        "Map",
        "This sample demonstrates how to author and save a map as an ArcGIS portal item (web map). Saving a map to arcgis.com requires an ArcGIS Online login.",
        "1. Pan and zoom to the extent you would like for your map.\n2. Choose a basemap from the list of available basemaps.\n3. Choose one or more operational layers to include.\n4. Provide a Client ID and Redirect URL for OAuth authentication with ArcGIS Online.\n5. Provide info for the new portal item, such as a Title, Description, and Tags.\n6. Click 'Save Map to Portal'.\n7. After successfully logging in to your ArcGIS Online account, the map will be saved to your default folder. \n8. You can make additional changes, update the map, and then re-save to store changes in the portal item.")]
    public partial class AuthorMap
    {
        // Constants for OAuth-related values ...
        // URL of the server to authenticate with
        private string ServerUrl = "https://www.arcgis.com/sharing/rest";

        // TODO: Add Client ID for an app registered with the server
        private string _appClientId = "lgAdHkYZYlwwfAhC";

        // TODO: Add URL for redirecting after a successful authorization
        //       Note - this must be a URL configured as a valid Redirect URI with your app
        private string _oAuthRedirectUrl = "my-ags-app://auth";

        // String array to store names of the available basemaps
        private readonly string[] _basemapNames = {
            "Light Gray",
            "Topographic",
            "Streets",
            "Imagery",
            "Ocean"
        };

        // Dictionary of operational layer names and URLs
        private readonly Dictionary<string, string> _operationalLayerUrls = new Dictionary<string, string>
        {
            {"World Elevations", "https://sampleserver6.arcgisonline.com/arcgis/rest/services/Elevation/WorldElevations/MapServer"},
            {"World Cities", "https://sampleserver6.arcgisonline.com/arcgis/rest/services/SampleWorldCities/MapServer/" },
            {"US Census Data", "https://sampleserver6.arcgisonline.com/arcgis/rest/services/Census/MapServer"}
        };

        public AuthorMap()
        {
            InitializeComponent();

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

        private void Initialize()
        {
            // Create the map
            MyMapView.Map = new Map();

            // Update the UI with basemaps and layers
            BasemapListBox.ItemsSource = _basemapNames;
            BasemapListBox.SelectedIndex = 0;
            OperationalLayerListBox.ItemsSource = _operationalLayerUrls;

            // Show the OAuth settings in the page
            ClientIdTextBox.Text = _appClientId;
            RedirectUrlTextBox.Text = _oAuthRedirectUrl;
            
            // Update the extent labels whenever the view point (extent) changes
            MyMapView.ViewpointChanged += (s, evt) => UpdateViewExtentLabels();
        }

        #region UI event handlers
        private void LayerSelectionChanged(object sender, SelectionChangedEventArgs e)
        {
            // Call a function to add operational layers to the map
            AddOperationalLayers();
        }

        private async void SaveMapClicked(object sender, RoutedEventArgs e)
        {
            try
            {
                // Don't attempt to save if the OAuth settings weren't provided
                if(String.IsNullOrEmpty(_appClientId) || String.IsNullOrEmpty(_oAuthRedirectUrl))
                {
                    MessageDialog dialog = new MessageDialog("OAuth settings were not provided.", "Cannot Save");
                    await dialog.ShowAsync();
                    return;
                }

                // Show the progress bar so the user knows work is happening
                SaveProgressBar.Visibility = Visibility.Visible;

                // Get the current map
                Map myMap = MyMapView.Map;

                // Apply the current extent as the map's initial extent
                myMap.InitialViewpoint = MyMapView.GetCurrentViewpoint(ViewpointType.BoundingGeometry);

                // Export the current map view to use as the item's thumbnail
                RuntimeImage thumbnailImg = await MyMapView.ExportImageAsync();

                // See if the map has already been saved (has an associated portal item)
                if (myMap.Item == null)
                {
                    // Get information for the new portal item
                    string title = TitleTextBox.Text;
                    string description = DescriptionTextBox.Text;
                    string tagText = TagsTextBox.Text;

                    // Make sure all required info was entered
                    if (String.IsNullOrEmpty(title) || String.IsNullOrEmpty(description) || String.IsNullOrEmpty(tagText))
                    {
                        throw new Exception("Please enter a title, description, and some tags to describe the map.");
                    }

                    // Call a function to save the map as a new portal item
                    await SaveNewMapAsync(MyMapView.Map, title, description, tagText.Split(','), thumbnailImg);

                    // Report a successful save
                    MessageDialog messageDialog = new MessageDialog("Saved '" + title + "' to ArcGIS Online!", "Map Saved");
                    await messageDialog.ShowAsync();
                }
                else
                {
                    // This is not the initial save, call SaveAsync to save changes to the existing portal item
                    await myMap.SaveAsync();

                    // Get the file stream from the new thumbnail image
                    Stream imageStream = await thumbnailImg.GetEncodedBufferAsync();

                    // Update the item thumbnail
                    ((PortalItem)myMap.Item).SetThumbnail(imageStream);                    
                    await myMap.SaveAsync();

                    // Report update was successful
                    MessageDialog messageDialog = new MessageDialog("Saved changes to '" + myMap.Item.Title + "'", "Updates Saved");
                    await messageDialog.ShowAsync();
                }
            }
            catch (Exception ex)
            {
                // Report error message
                MessageDialog messageDialog = new MessageDialog("Error saving map to ArcGIS Online: " + ex.Message);
                await messageDialog.ShowAsync();
            }
            finally
            {
                // Hide the progress bar
                SaveProgressBar.Visibility = Visibility.Collapsed;
            }
        }

        private void ClearMapClicked(object sender, RoutedEventArgs e)
        {
            // Create a new map (will not have an associated PortalItem)
            MyMapView.Map = new Map(Basemap.CreateLightGrayCanvas());

            // Reset the basemap selection in the UI
            BasemapListBox.SelectedIndex = 0;

            // Reset the layer selection in the UI;
            OperationalLayerListBox.SelectedIndex = -1;

            // Reset the extent labels
            UpdateViewExtentLabels();
        }
        #endregion

        private void ApplyBasemap(string basemapName)
        {
            // Get the current map
            Map myMap = MyMapView.Map;

            // Set the basemap for the map according to the user's choice in the list box
            switch (basemapName)
            {
                case "Light Gray":
                    // Set the basemap to Light Gray Canvas
                    myMap.Basemap = Basemap.CreateLightGrayCanvas();
                    break;
                case "Topographic":
                    // Set the basemap to Topographic
                    myMap.Basemap = Basemap.CreateTopographic();
                    break;
                case "Streets":
                    // Set the basemap to Streets
                    myMap.Basemap = Basemap.CreateStreets();
                    break;
                case "Imagery":
                    // Set the basemap to Imagery
                    myMap.Basemap = Basemap.CreateImagery();
                    break;
                case "Ocean":
                    // Set the basemap to Oceans
                    myMap.Basemap = Basemap.CreateOceans();
                    break;
            }
        }

        private void AddOperationalLayers()
        {
            // Clear the operational layers from the map
            Map myMap = MyMapView.Map;
            myMap.OperationalLayers.Clear();

            // Loop through the selected items in the operational layers list box
            foreach (KeyValuePair<string, string> item in OperationalLayerListBox.SelectedItems)
            {
                // Get the service uri for each selected item 
                KeyValuePair<string, string> layerInfo = item;
                Uri layerUri = new Uri(layerInfo.Value);

                // Create a new map image layer, set it 50% opaque, and add it to the map
                ArcGISMapImageLayer layer = new ArcGISMapImageLayer(layerUri)
                {
                    Opacity = 0.5
                };
                myMap.OperationalLayers.Add(layer);
            }
        }

        private async Task SaveNewMapAsync(Map myMap, string title, string description, string[] tags, RuntimeImage img)
        {
            // Challenge the user for portal credentials (OAuth credential request for arcgis.com)
            CredentialRequestInfo loginInfo = new CredentialRequestInfo
            {

                // Use the OAuth implicit grant flow
                GenerateTokenOptions = new GenerateTokenOptions
                {
                    TokenAuthenticationType = TokenAuthenticationType.OAuthImplicit
                },

                // Indicate the url (portal) to authenticate with (ArcGIS Online)
                ServiceUri = new Uri("https://www.arcgis.com/sharing/rest")
            };

            try
            {
                // Get a reference to the (singleton) AuthenticationManager for the app
                AuthenticationManager thisAuthenticationManager = AuthenticationManager.Current;

                // Call GetCredentialAsync on the AuthenticationManager to invoke the challenge handler
                await thisAuthenticationManager.GetCredentialAsync(loginInfo, false);
            }
            catch (OperationCanceledException)
            {
                // user canceled the login
                throw new Exception("Portal log in was canceled.");
            }

            // Get the ArcGIS Online portal (will use credential from login above)
            ArcGISPortal agsOnline = await ArcGISPortal.CreateAsync();

            // Save the current state of the map as a portal item in the user's default folder
            await myMap.SaveAsAsync(agsOnline, null, title, description, tags, img);
        }

        private void UpdateViewExtentLabels()
        {
            // Get the current view point for the map view
            Viewpoint currentViewpoint = MyMapView.GetCurrentViewpoint(ViewpointType.BoundingGeometry);
            if (currentViewpoint == null) { return; }

            // Get the current map extent (envelope) from the view point
            Envelope currentExtent = currentViewpoint.TargetGeometry as Envelope;

            // Project the current extent to geographic coordinates (longitude / latitude)
            Envelope currentGeoExtent = (Envelope)GeometryEngine.Project(currentExtent, SpatialReferences.Wgs84);

            // Fill the app text boxes with min / max longitude (x) and latitude (y) to four decimal places
            XMinTextBox.Text = currentGeoExtent.XMin.ToString("0.####");
            YMinTextBox.Text = currentGeoExtent.YMin.ToString("0.####");
            XMaxTextBox.Text = currentGeoExtent.XMax.ToString("0.####");
            YMaxTextBox.Text = currentGeoExtent.YMax.ToString("0.####");
        }

        #region OAuth helpers

        private void SaveOAuthSettingsClicked(object sender, RoutedEventArgs e)
        {
            // Settings were provided, update the configuration settings for OAuth authorization
            _appClientId = ClientIdTextBox.Text.Trim();
            _oAuthRedirectUrl = RedirectUrlTextBox.Text.Trim();

            // Update authentication manager with the OAuth settings
            UpdateAuthenticationManager();

            // Update the UI
            SaveMapGrid.Visibility = Visibility.Visible;
            OAuthSettingsGrid.Visibility = Visibility.Collapsed;
        }

        private void UpdateAuthenticationManager()
        {
            // Register the server information with the AuthenticationManager
            ServerInfo portalServerInfo = new ServerInfo
            {
                ServerUri = new Uri(ServerUrl),
                OAuthClientInfo = new OAuthClientInfo
                {
                    ClientId = _appClientId,
                    RedirectUri = new Uri(_oAuthRedirectUrl)
                },
                // Specify OAuthAuthorizationCode if you need a refresh token (and have specified a valid client secret)
                // Otherwise, use OAuthImplicit
                TokenAuthenticationType = TokenAuthenticationType.OAuthImplicit
            };

            // Get a reference to the (singleton) AuthenticationManager for the app
            AuthenticationManager thisAuthenticationManager = AuthenticationManager.Current;

            // Register the server information
            thisAuthenticationManager.RegisterServer(portalServerInfo);

            // Create a new ChallengeHandler that uses a method in this class to challenge for credentials
            thisAuthenticationManager.ChallengeHandler = new ChallengeHandler(CreateCredentialAsync);
        }

        // ChallengeHandler function for AuthenticationManager that will be called whenever access to a secured
        // resource is attempted
        public async Task<Credential> CreateCredentialAsync(CredentialRequestInfo info)
        {
            OAuthTokenCredential credential = null;

            try
            {
                // Create generate token options if necessary
                if (info.GenerateTokenOptions == null)
                {
                    info.GenerateTokenOptions = new GenerateTokenOptions();
                }

                // IOAuthAuthorizeHandler will challenge the user for credentials
                credential = await AuthenticationManager.Current.GenerateCredentialAsync
                    (
                            info.ServiceUri,
                            info.GenerateTokenOptions
                    ) as OAuthTokenCredential;
            }
            catch (Exception)
            {
                // Exception will be reported in calling function
                throw;
            }

            return credential;
        }
        #endregion

        private void BasemapListView_SelectionChanged(object sender, SelectionChangedEventArgs e)
        {
            // Get the name of the desired basemap 
            string name = e.AddedItems[0].ToString();

            // Apply the basemap to the current map
            ApplyBasemap(name);
        }
    }
}