App.xaml.cs

using UWP_Visual_Asset_Generator.ViewModels;
using UWP_Visual_Asset_Generator.Views;
using Microsoft.AppCenter;
using Microsoft.AppCenter.Analytics;
using Microsoft.AppCenter.Crashes;
using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Runtime.InteropServices.WindowsRuntime;
using Windows.ApplicationModel;
using Windows.ApplicationModel.Activation;
using Windows.ApplicationModel.Core;
using Windows.Foundation;
using Windows.Foundation.Collections;
using Windows.Services.Store;
using Windows.UI;
using Windows.UI.Core;
using Windows.UI.ViewManagement;
using Windows.UI.Xaml;
using Windows.UI.Xaml.Controls;
using Windows.UI.Xaml.Controls.Primitives;
using Windows.UI.Xaml.Data;
using Windows.UI.Xaml.Input;
using Windows.UI.Xaml.Media;
using Windows.UI.Xaml.Media.Animation;
using Windows.UI.Xaml.Navigation;
using Microsoft.Toolkit.Uwp.Helpers;

namespace UWP_Visual_Asset_Generator
{
    /// <summary>
    /// Provides application-specific behavior to supplement the default Application class.
    /// </summary>
    sealed partial class App : Application
    {
        private static MainViewModel _mainViewModel;
        public static Frame rootFrame;

        public static TimeSpan ThinkingTinyPauseInMs = new TimeSpan(0, 0, 0, 0, 25); //5% of a second
        public static TimeSpan ThinkingShortPauseInMs = new TimeSpan(0,0,0,0,500); //Half a second
        public static TimeSpan ThinkingMediumPauseInMs = new TimeSpan(0, 0, 0, 0, 1000); //One second
        public static TimeSpan ThinkingLongPauseInMs = new TimeSpan(0, 0, 0, 0, 2000); //Two seconds

        private const string AppCenterAppKey = "63c401f8-a93c-4767-85de-53d2cfe74b2e";

        public static Page mainPage { get; set; }

        /// <summary>
        /// Initializes the singleton application object.  This is the first line of authored code
        /// executed, and as such is the logical equivalent of main() or WinMain().
        /// </summary>
        public App()
        {
            this.InitializeComponent();
            this.Suspending += OnSuspending;

            #if !DEBUG
            AppCenter.Start(AppCenterAppKey, typeof(Analytics), typeof(Crashes));
            #endif
            _mainViewModel = new MainViewModel();
        }

        public static MainViewModel mainViewModel
        {
            get
            {
                if (_mainViewModel == null)
                {
                    _mainViewModel = new MainViewModel();
                }
                return _mainViewModel;
            }
            set
            {
                _mainViewModel = value;
            }
        }

        /// <summary>
        /// Invoked when the application is launched normally by the end user.  Other entry points
        /// will be used such as when the application is launched to open a specific file.
        /// </summary>
        /// <param name="e">Details about the launch request and process.</param>
        protected override void OnLaunched(LaunchActivatedEventArgs e)
        {
            SystemInformation.Instance.TrackAppUse(e);

            rootFrame = Window.Current.Content as Frame;

            // Do not repeat app initialization when the Window already has content,
            // just ensure that the window is active
            if (rootFrame == null)
            {
                // Create a Frame to act as the navigation context and navigate to the first page
                rootFrame = new Frame();
                rootFrame.ContentTransitions = new TransitionCollection();
                rootFrame.ContentTransitions.Add(new EntranceThemeTransition());

                rootFrame.NavigationFailed += OnNavigationFailed;
                SystemNavigationManager.GetForCurrentView().BackRequested += OnBackRequested;

                if (e.PreviousExecutionState == ApplicationExecutionState.Terminated)
                {
                    //TODO: Load state from previously suspended application
                }

                // Place the frame in the current Window
                Window.Current.Content = rootFrame;
                // Register a handler for BackRequested events and set the
                // visibility of the Back button
                SystemNavigationManager.GetForCurrentView().AppViewBackButtonVisibility = rootFrame.CanGoBack ? AppViewBackButtonVisibility.Visible : AppViewBackButtonVisibility.Collapsed;
            }

            try
            {
                CoreApplication.GetCurrentView().TitleBar.ExtendViewIntoTitleBar = true;
                ApplicationViewTitleBar titleBar = ApplicationView.GetForCurrentView().TitleBar;
                titleBar.ButtonBackgroundColor = Colors.Transparent;
                titleBar.ButtonInactiveBackgroundColor = Colors.Transparent;
            }
            catch (Exception ex)
            {
                //Visual settinng not working (old version?)
            }

            if (e.PrelaunchActivated == false)
            {
                if (rootFrame.Content == null)
                {
                    // When the navigation stack isn't restored navigate to the first page,
                    // configuring the new page by passing required information as a navigation
                    // parameter
                    rootFrame.Navigate(typeof(MainView), e.Arguments);
                }
                // Ensure the current window is active
                Window.Current.Activate();
            }
        }

        /// <summary>
        /// Invoked when Navigation to a certain page fails
        /// </summary>
        /// <param name="sender">The Frame which failed navigation</param>
        /// <param name="e">Details about the navigation failure</param>
        void OnNavigationFailed(object sender, NavigationFailedEventArgs e)
        {
            throw new Exception("Failed to load Page " + e.SourcePageType.FullName);
        }

        private void OnBackRequested(object sender, BackRequestedEventArgs e)
        {
            //Frame rootFrame = Window.Current.Content as Frame;
            if (rootFrame.CanGoBack)
            {
                e.Handled = true;
                rootFrame.GoBack();
            }
        }

        /// <summary>
        /// Invoked when application execution is being suspended.  Application state is saved
        /// without knowing whether the application will be terminated or resumed with the contents
        /// of memory still intact.
        /// </summary>
        /// <param name="sender">The source of the suspend request.</param>
        /// <param name="e">Details about the suspend request.</param>
        private void OnSuspending(object sender, SuspendingEventArgs e)
        {
            var deferral = e.SuspendingOperation.GetDeferral();
            //TODO: Save application state and stop any background activity
            deferral.Complete();
        }
    }
}