App.xaml.cs

using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Runtime.InteropServices.WindowsRuntime;
using System.Threading.Tasks;
using Windows.ApplicationModel;
using Windows.ApplicationModel.Activation;
using Windows.Foundation;
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 NGopher.Common;

// The Blank Application template is documented at http://go.microsoft.com/fwlink/?LinkId=391641

namespace NGopher
{
    /// <summary>
    /// Provides application-specific behavior to supplement the default Application class.
    /// </summary>
    public sealed partial class App : Application
    {
        private TransitionCollection transitions;
        public ContinuationManager ContinuationManager { get; private 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 += this.OnSuspending;

            Windows.Phone.UI.Input.HardwareButtons.BackPressed += HardwareButtons_BackPressed;
        }

        void HardwareButtons_BackPressed(object sender, Windows.Phone.UI.Input.BackPressedEventArgs e)
        {
            Frame rootFrame = Window.Current.Content as Frame;

            if (rootFrame != null && rootFrame.CanGoBack)
            {
                e.Handled = true;
                rootFrame.GoBack();
            }
        }

        private Frame CreateRootFrame()
        {
            Frame rootFrame = Window.Current.Content as Frame;

            if (rootFrame == null)
            {
                rootFrame = new Frame();
                rootFrame.NavigationFailed += OnNavigationFailed;
                Window.Current.Content = rootFrame;
            }

            return rootFrame;
        }

        private async Task RestoreStatusAsync(ApplicationExecutionState previousExecutionState)
        {
            if (previousExecutionState == ApplicationExecutionState.Terminated)
            {
                try
                {
                    await SuspensionManager.RestoreAsync();
                }
                catch (SuspensionManagerException)
                {
                    // silently continue, assuming nothing bad happened...
                }
            }
        }

        /// <summary>
        /// Handle OnActivated event to deal with File Open/Save continuation activation kinds
        /// </summary>
        /// <param name="e">application activated event arguments, it can be casted to a proper sub-type based on ActivationKind</param>
        protected async override void OnActivated(IActivatedEventArgs e)
        {
            if (e.Kind == ActivationKind.Protocol)
            {
                ProtocolActivatedEventArgs args = e as ProtocolActivatedEventArgs;

                if (args != null && args.Uri.AbsoluteUri.StartsWith("gopher://"))
                {
                    var x = args.Uri.AbsoluteUri.Remove(0, 9).Split(new[] { '/' }, 2);
                    var path = "";
                    try { path = x[1]; }
                    catch (IndexOutOfRangeException) { }

                    var port = "70";
                    try { port = x[0].Split(':')[1]; }
                    catch (IndexOutOfRangeException) { }

                    CreateRootFrame().Navigate(typeof(DirectoryListingPage), x[0] + "\x01" + port + "\x02/" + path);
                    Window.Current.Activate();
                }
                return;
            }
            base.OnActivated(e);

            ContinuationManager = new ContinuationManager();
            Frame rootFrame = CreateRootFrame();
            await RestoreStatusAsync(e.PreviousExecutionState);

            if (rootFrame.Content == null)
            {
                rootFrame.Navigate(typeof (ServerListPage));
            }

            var continuationEventArgs = e as IContinuationActivatedEventArgs;
            if (continuationEventArgs != null)
            {
                ContinuationManager.Continue(continuationEventArgs, rootFrame);
            }

            Window.Current.Activate();
        }

        private void OnNavigationFailed(object sender, NavigationFailedEventArgs e)
        {
            throw new Exception("failed to load page " + e.SourcePageType.FullName);
        }

        /// <summary>
        /// Invoked when the application is launched normally by the end user.  Other entry points
        /// will be used when the application is launched to open a specific file, to display
        /// search results, and so forth.
        /// </summary>
        /// <param name="e">Details about the launch request and process.</param>
        protected override void OnLaunched(LaunchActivatedEventArgs e)
        {
#if DEBUG
            if (System.Diagnostics.Debugger.IsAttached)
            {
                this.DebugSettings.EnableFrameRateCounter = true;
            }
#endif

            Frame rootFrame = CreateRootFrame();

            rootFrame.CacheSize = 1;

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

            if (rootFrame.Content == null)
            {
                // Removes the turnstile navigation for startup.
                if (rootFrame.ContentTransitions != null)
                {
                    this.transitions = new TransitionCollection();
                    foreach (var c in rootFrame.ContentTransitions)
                    {
                        this.transitions.Add(c);
                    }
                }

                rootFrame.ContentTransitions = null;
                rootFrame.Navigated += this.RootFrame_FirstNavigated;

                // When the navigation stack isn't restored navigate to the first page,
                // configuring the new page by passing required information as a navigation
                // parameter
                if (!rootFrame.Navigate(typeof(ServerListPage), e.Arguments))
                {
                    throw new Exception("Failed to create initial page");
                }
            }

            // Ensure the current window is active
            Window.Current.Activate();
        }

        /// <summary>
        /// Restores the content transitions after the app has launched.
        /// </summary>
        /// <param name="sender">The object where the handler is attached.</param>
        /// <param name="e">Details about the navigation event.</param>
        private void RootFrame_FirstNavigated(object sender, NavigationEventArgs e)
        {
            var rootFrame = sender as Frame;
            rootFrame.ContentTransitions = this.transitions ?? new TransitionCollection() { new NavigationThemeTransition() };
            rootFrame.Navigated -= this.RootFrame_FirstNavigated;
        }

        /// <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 async void OnSuspending(object sender, SuspendingEventArgs e)
        {
            var deferral = e.SuspendingOperation.GetDeferral();

            // TODO: Save application state and stop any background activity

            await SuspensionManager.SaveAsync();

            deferral.Complete();
        }
    }
}