sharee.bike-App/LastenradBayern/TINK/View/MyBikes/MyBikesPage.xaml.cs

using Plugin.Connectivity;
using System;
using System.Threading;
using System.Threading.Tasks;
#if USEFLYOUT
using TINK.View.MasterDetail;
#endif
using Xamarin.Forms;
using Xamarin.Forms.Xaml;

namespace TINK.View.MyBikes
{
    using Serilog;
    using TINK.Model;
    using TINK.Model.Device;
    using TINK.ViewModel.MyBikes;
    using Xamarin.CommunityToolkit.Extensions;

    [XamlCompilation(XamlCompilationOptions.Compile)]
    public partial class MyBikesPage : ContentPage, IViewService
    {
        /// <summary> Refernce to view model. </summary>
        MyBikesPageViewModel m_oViewModel = null;

        /// <summary> Initialization status to ensure initialization logic is not called multiple times. </summary>
        private bool isInitializationStarted = false;

        /// <summary>
        /// Constructs a my bikes page.
        /// </summary>
        public MyBikesPage()
        {
        }

        /// <summary>
        /// Invoked when page is shown. 
        /// Starts update process.
        /// </summary>
        protected async override void OnAppearing()
        {
            // Don't repeat the initialization if it has been completed already.
            if (isInitializationStarted) return;
                isInitializationStarted = true;

            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.OnAppearing();
                isInitializationStarted = false;
                return;
            }

            try
            {
                var model = App.ModelRoot;

                // Backup synchronization context when called from GUI-thread.
                var synchronizationContext = SynchronizationContext.Current;

                m_oViewModel = new MyBikesPageViewModel(
                    model.ActiveUser,
                    App.PermissionsService,
                    App.BluetoothService,
                    Device.RuntimePlatform,
                    () => model.GetIsConnected(),
                    (isConnected) => model.GetConnector(isConnected),
                    App.LocationServicesContainer.Active,
                    model.LocksServices.Active,
                    model.Stations,
                    model.Polling,
                    (d, obj) => synchronizationContext.Post(d, obj),
                    model.SmartDevice,
                    this,
                    (url) => DependencyService.Get<IExternalBrowserService>().OpenUrl(url))
                {
                    IsReportLevelVerbose = model.IsReportLevelVerbose
                };
            }
            catch (Exception exception)
            {
                Log.ForContext<MyBikesPage>().Error("Displaying bikes at station page failed. {Exception}", exception);
                await DisplayAlert("Fehler", $"Seite Räder an Station kann nicht angezeigt werden. ${exception.Message}", "OK");
                isInitializationStarted = false;
                return;
            }

            InitializeComponent();

            BindingContext = m_oViewModel;
            MyBikesListView.ItemsSource = m_oViewModel;

            await m_oViewModel.OnAppearing();
            isInitializationStarted = false;
        }

        /// <summary>
        /// Invoked when pages is closed/ hidden. 
        /// Stops update process.
        /// </summary>
        protected async override void OnDisappearing()
        {
            if (m_oViewModel == null)
            {
                // View model might be null (Example: Occured when page to querry for location permissions was opened)
                return;
            }

            await m_oViewModel.OnDisappearing();
        }

        /// <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
        /// <summary> Displays user feedback popup.</summary>
        /// <param name="co2Saving"> Co2 saving information.</param>
        /// <returns>User feedback.</returns>
        public async Task<IUserFeedback> DisplayUserFeedbackPopup(string co2Saving = null) => await Navigation.ShowPopupAsync<FeedbackPopup.Result>(new FeedbackPopup(co2Saving));
#endif
    }
}