ServiceProvidersViewModel.cs

using CommunityToolkit.Mvvm.ComponentModel;
using System.Collections.ObjectModel;
using System.ComponentModel;
using IServiceProvider = Waher.Networking.XMPP.Contracts.IServiceProvider;
 
namespace NeuroAccessMaui.UI.Pages.Wallet.ServiceProviders
{
    public partial class ServiceProvidersViewModel : XmppViewModel
    {
        private const int defaultIconHeight = 150;
 
        private readonly ServiceProvidersNavigationArgs? navigationArgs;
 
        public ServiceProvidersViewModel(ServiceProvidersNavigationArgs? Args)
            : base()
        {
            this.navigationArgs = Args;
 
            if (Args is not null)
            {
                this.Title = Args.Title;
                this.Description = Args.Description;
 
                foreach (IServiceProvider ServiceProvider in Args.ServiceProviders)
                {
                    this.ServiceProviders.Add(new ServiceProviderViewModel(ServiceProvider, defaultIconHeight, this));
                }
            }
        }
 
        public override async Task OnDisposeAsync()
        {
            if (this.navigationArgs?.ServiceProvider is TaskCompletionSource<IServiceProvider> TaskSource)
                TaskSource.TrySetResult(null);
 
            await base.OnDisposeAsync();
        }
 
        #region Properties
 
        [ObservableProperty]
        private string? title;
 
        [ObservableProperty]
        private string? description;
 
        public ObservableCollection<ServiceProviderViewModel> ServiceProviders { get; } = [];
 
        [ObservableProperty]
        private ServiceProviderViewModel? selectedServiceProvider;
 
        protected override void OnPropertyChanged(PropertyChangedEventArgs e)
        {
            base.OnPropertyChanged(e);
 
            switch (e.PropertyName)
            {
                case nameof(this.SelectedServiceProvider):
                    MainThread.BeginInvokeOnMainThread(async () =>
                    {
                        await this.TrySetResultAndClosePage(this.SelectedServiceProvider?.ServiceProvider);
                    });
                    break;
            }
        }
 
        #endregion
 
        public override Task GoBack()
        {
            return this.TrySetResultAndClosePage(null);
        }
 
        private async Task TrySetResultAndClosePage(IServiceProvider? ServiceProvider)
        {
            TaskCompletionSource<IServiceProvider?>? TaskSource = null;
 
            if (this.navigationArgs is not null)
            {
                TaskSource = this.navigationArgs.ServiceProvider;
                this.navigationArgs.ServiceProvider = null;
            }
 
            await base.GoBack();
 
            TaskSource?.TrySetResult(ServiceProvider);
        }
 
        internal async Task SelectServiceProvider(ServiceProviderViewModel ServiceProvider)
        {
            await MainThread.InvokeOnMainThreadAsync(async () =>
            {
                await this.TrySetResultAndClosePage(ServiceProvider.ServiceProvider);
            });
        }
    }
}