Show callout

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// Copyright 2017 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.UI;
using Esri.ArcGISRuntime.UI.Controls;
using Foundation;
using UIKit;

namespace ArcGISRuntime.Samples.ShowCallout
{
    [Register("ShowCallout")]
    [ArcGISRuntime.Samples.Shared.Attributes.Sample(
        name: "Show callout",
        category: "MapView",
        description: "Show a callout with the latitude and longitude of user-tapped points.",
        instructions: "Tap anywhere on the map. A callout showing the WGS84 coordinates for the tapped point will appear.",
        tags: new[] { "balloon", "bubble", "callout", "flyout", "flyover", "info window", "popup", "tap" })]
    public class ShowCallout : UIViewController
    {
        // Hold references to UI controls.
        private MapView _myMapView;

        public ShowCallout()
        {
            Title = "Show callout";
        }

        private void Initialize()
        {
            // Show a streets basemap.
            _myMapView.Map = new Map(BasemapStyle.ArcGISStreets);
        }

        private void MapView_GeoViewTapped(object sender, GeoViewInputEventArgs e)
        {
            // Get the user-tapped location.
            MapPoint mapLocation = e.Location;

            // Project the map point to WGS84 for latitude/longitude display.
            MapPoint projectedLocation = (MapPoint) GeometryEngine.Project(mapLocation, SpatialReferences.Wgs84);

            // Format the display callout string based upon the projected map point (example: "Lat: 100.123, Long: 100.234").
            string mapLocationDescription = $"Lat: {projectedLocation.Y:F3} Long:{projectedLocation.X:F3}";

            // Create a new callout definition using the formatted string.
            CalloutDefinition myCalloutDefinition = new CalloutDefinition("Location:", mapLocationDescription);

            // Display the callout.
            _myMapView.ShowCalloutAt(mapLocation, myCalloutDefinition);
        }

        public override void ViewDidLoad()
        {
            base.ViewDidLoad();
            Initialize();
        }

        public override void LoadView()
        {
            // Create the views.
            View = new UIView() { BackgroundColor = ApplicationTheme.BackgroundColor };

            _myMapView = new MapView();
            _myMapView.TranslatesAutoresizingMaskIntoConstraints = false;

            UILabel helpLabel = new UILabel
            {
                Text = "Tap to show a callout.",
                AdjustsFontSizeToFitWidth = true,
                TextAlignment = UITextAlignment.Center,
                BackgroundColor = UIColor.FromWhiteAlpha(0, .6f),
                TextColor = UIColor.White,
                Lines = 1,
                TranslatesAutoresizingMaskIntoConstraints = false
            };

            // Add the views.
            View.AddSubviews(_myMapView, helpLabel);

            // Lay out the views.
            NSLayoutConstraint.ActivateConstraints(new[]
            {
                _myMapView.TopAnchor.ConstraintEqualTo(View.SafeAreaLayoutGuide.TopAnchor),
                _myMapView.BottomAnchor.ConstraintEqualTo(View.BottomAnchor),
                _myMapView.LeadingAnchor.ConstraintEqualTo(View.LeadingAnchor),
                _myMapView.TrailingAnchor.ConstraintEqualTo(View.TrailingAnchor),

                helpLabel.TopAnchor.ConstraintEqualTo(View.SafeAreaLayoutGuide.TopAnchor),
                helpLabel.LeadingAnchor.ConstraintEqualTo(View.LeadingAnchor),
                helpLabel.TrailingAnchor.ConstraintEqualTo(View.TrailingAnchor),
                helpLabel.HeightAnchor.ConstraintEqualTo(40)
            });
        }

        public override void ViewWillAppear(bool animated)
        {
            base.ViewWillAppear(animated);

            // Subscribe to events.
            _myMapView.GeoViewTapped += MapView_GeoViewTapped;
        }

        public override void ViewDidDisappear(bool animated)
        {
            base.ViewDidDisappear(animated);

            // Unsubscribe from events, per best practice.
            _myMapView.GeoViewTapped -= MapView_GeoViewTapped;
        }
    }
}