GeoMapViewModel.cs

using CommunityToolkit.Mvvm.ComponentModel;
using CommunityToolkit.Mvvm.Input;
using NeuroAccessMaui.UI.Popups;
using Waher.Runtime.Geo;
using System;
using Mapsui.Projections;
using Mapsui.UI.Maui;
using NeuroAccessMaui.Services;
 
namespace NeuroAccessMaui.UI.Popups.Password
{
    public partial class GeoMapViewModel : ReturningPopupViewModel<string>
    {
        // Expose the MapControl so we can read the viewport center
        public MapControl? MapControl { get; set; }
 
        public GeoPosition? InitialCoordinate { get; }
 
        public GeoMapViewModel(double? Latitude = null, double? Longitude = null)
        {
            if (Latitude.HasValue && Longitude.HasValue)
                InitialCoordinate = new GeoPosition(Latitude.Value, Longitude.Value);
        }
 
        [RelayCommand]
        public async Task Confirm()
        {
            if (MapControl?.Map?.Navigator.Viewport is null)
            {
                this.TrySetResult(null);
                await ServiceRef.PopupService.PopAsync();
                return;
            }
 
            var vp = MapControl.Map.Navigator.Viewport;
            // Convert world (Mercator) to lon/lat
            var (lon, lat) = SphericalMercator.ToLonLat(vp.CenterX, vp.CenterY);
            this.TrySetResult($"{lon},{lat}");
            await ServiceRef.PopupService.PopAsync();
        }
    }
}