sharee.bike-App/Meinkonrad/TINK/View/FindBike/FindBikePage.xaml.cs

using System;
using System.Threading;
using System.Threading.Tasks;
using Serilog;
using TINK.Model.Bikes.BikeInfoNS.DriveNS.BatteryNS;
using TINK.Model.Device;
using TINK.MultilingualResources;
using TINK.ViewModel.FindBike;
using Xamarin.CommunityToolkit.Extensions;
using Xamarin.Forms;
using Xamarin.Forms.Xaml;

namespace TINK.View.FindBike
{
	[XamlCompilation(XamlCompilationOptions.Compile)]
	public partial class FindBikePage : ContentPage, IViewService
	{
		/// <summary> Refernce to view model. </summary>
		FindBikePageViewModel m_oViewModel = null;

		/// <summary>
		/// Holds a value indicating whether page already subscribed to shell item changes or not.
		/// </summary>
		private bool _IsShellItemChangedReceived = false;

		public FindBikePage() { }

		/// <summary>
		/// Invoked when page is shown. 
		/// Starts update process.
		/// </summary>
		protected async override void OnAppearing()
		{
			if (m_oViewModel != null)
			{
				// No need to create view model, set binding context an items source if already done.
				// If done twice tap events are fired multiple times (when hiding page using home button).
				await m_oViewModel.OnAppearingOrRefresh();
				return;
			}

			try
			{
				var model = App.ModelRoot;

				m_oViewModel = new FindBikePageViewModel(
					model.ActiveUser,
					App.PermissionsService,
					App.BluetoothService,
					Device.RuntimePlatform,
					() => model.GetIsConnected(),
					(isConnected) => model.GetConnector(isConnected),
					App.LocationServicesContainer.Active,
					model.LocksServices.Active,
					model.Stations,
					model.Polling,
					model.PostAction,
					model.SmartDevice,
					this,
					(url) => DependencyService.Get<IExternalBrowserService>().OpenUrl(url))
				{
					IsReportLevelVerbose = model.IsReportLevelVerbose
				};
			}
			catch (Exception exception)
			{
				Log.ForContext<FindBikePage>().Error("Displaying bikes at station page failed. {Exception}", exception);
				await DisplayAlert(
					AppResources.ErrorPageNotLoadedTitle,
					$"{AppResources.ErrorPageNotLoaded}\r\n{exception.Message}",
					AppResources.MessageAnswerOk);
				return;

			}

			InitializeComponent();

			BindingContext = m_oViewModel;
			FindBikeListView.ItemsSource = m_oViewModel;

			await m_oViewModel.OnAppearingOrRefresh();
		}

		/// <summary>
		/// Invoked when page is disappearing to
		/// - stop the update process
		/// - to subscribe to events.
		/// </summary>
		protected async override void OnDisappearing()
		{
			if (!_IsShellItemChangedReceived && Shell.Current != null)
			{
				// Subscribe to events.
				// Do not do this on startup because Shell.Current is null, if FindeBikePage is startup page.
				Shell.Current.Navigated += (sender, e) =>
				{
					if (e.Source != ShellNavigationSource.ShellItemChanged)
					{
						// Nothing to do.
						return;
					}

					// Reset previous user input after switch of pages to allow user to select a differnt bike if one has been selected before.
					m_oViewModel.BikeIdUserInput = String.Empty;
				};

			}

			_IsShellItemChangedReceived = true;

			await (m_oViewModel?.OnDisappearing() ?? Task.CompletedTask);
		}

		/// <summary>
		/// Displays alert message.
		/// </summary>
		/// <param name="p_strTitle">Title of message.</param>
		/// <param name="p_strMessage">Message to display.</param>
		/// <param name="p_strCancel">Type of buttons.</param>
		public new async Task DisplayAlert(string p_strTitle, string p_strMessage, string p_strCancel)
			=> await App.Current.MainPage.DisplayAlert(p_strTitle, p_strMessage, p_strCancel);

		/// <summary> Displays alert message.</summary>
		/// <param name="title">Title of message.</param>
		/// <param name="message">Message to display.</param>
		/// <param name="details">Detailed error description.</param>
		/// <param name="cancel">Type of buttons.</param>
		public async Task DisplayAdvancedAlert(
			string title,
			string message,
			string details,
			string cancel)
			=> await App.Current.MainPage.DisplayAlert(title, $"{message}\r\nDetails:\r\n{details}", cancel);

		/// <summary> Displays detailed alert message.</summary>
		/// <param name="title">Title of message.</param>
		/// <param name="message">Message to display.</param>
		/// <param name="details">Detailed error description.</param>
		/// <param name="accept">Text of accept button.</param>
		/// <param name="cancel">Text of cancel button.</param>
		/// <returns>True if user pressed accept.</returns>
		public async Task<bool> DisplayAdvancedAlert(string title, string message, string details, string accept, string cancel)
			=> await App.Current.MainPage.DisplayAlert(title, !string.IsNullOrEmpty(details) ? $"{message}\r\nDetails:\r\n{details}" : $"{message}", accept, cancel);

		/// <summary>
		/// Displays alert message.
		/// </summary>
		/// <param name="p_strTitle">Title of message.</param>
		/// <param name="p_strMessage">Message to display.</param>
		/// <param name="p_strAccept">Text of accept button.</param>
		/// <param name="p_strCancel">Text of button.</param>
		/// <returns>True if user pressed accept.</returns>
		public new async Task<bool> DisplayAlert(string p_strTitle, string p_strMessage, string p_strAccept, string p_strCancel)
			=> await App.Current.MainPage.DisplayAlert(p_strTitle, p_strMessage, p_strAccept, p_strCancel);

#if USEFLYOUT
        public void ShowPage(ViewTypes p_oType, string p_strTitle = null)
            => throw new NotImplementedException();
#else
		/// <summary> Shows a page.</summary>
		/// <param name="route">Route of the page to show.</param>
		public async Task ShowPage(string route) => await Shell.Current.GoToAsync(route);
#endif

		/// <summary> Pushes a page onto the modal stack. </summary>
		/// <param name="typeOfPage">Page to display.</param>
		public async Task PushModalAsync(ViewTypes typeOfPage)
			=> await Navigation.PushModalAsync((Page)Activator.CreateInstance(typeOfPage.GetViewType()));

		/// <summary> Pops a page from the modal stack. </summary>
		public Task PopModalAsync() => throw new NotSupportedException();

		/// <summary> Pushes a page onto the stack. </summary>
		/// <param name="p_oTypeOfPage">Page to display.</param>
		public Task PushAsync(ViewTypes p_oTypeOfPage) => throw new NotSupportedException();

#if USCSHARP9
        public async Task<IViewService.IUserFeedback> DisplayUserFeedbackPopup() => await Navigation.ShowPopupAsync<FeedbackPopup.Result>(new FeedbackPopup());
#else
		public async Task<IUserFeedback> DisplayUserFeedbackPopup(IBatteryMutable battery = null, string co2Saving = null) => await Navigation.ShowPopupAsync<FeedbackPopup.Result>(new FeedbackPopup(battery, co2Saving));
#endif
	}
}