Implement asynchronous startup with splash screen

- Adds a splash screen to provide visual feedback during application startup.
- The initialization logic has been refactored to be fully asynchronous. Heavy tasks, such as database loading, are now executed on a background thread.

Author: mx7b7

src/CodeSnip/App.xaml

@@ -2,8 +2,7 @@
              xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
              xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
              xmlns:mah="clr-namespace:MahApps.Metro.Controls;assembly=MahApps.Metro"
-             xmlns:local="clr-namespace:CodeSnip"
-             StartupUri="MainWindow.xaml" >
+             xmlns:local="clr-namespace:CodeSnip" >
     <Application.Resources>
         <ResourceDictionary>
             <ResourceDictionary.MergedDictionaries>

src/CodeSnip/App.xaml.cs

@@ -1,23 +1,32 @@
-using ControlzEx.Theming;
-using System.Windows;
-using System.Windows.Media;
+using System.Windows;
 
 namespace CodeSnip
 {
     public partial class App : Application
     {
+        protected override async void OnStartup(StartupEventArgs e)
+        {
+            base.OnStartup(e);
 
-        //protected override void OnStartup(StartupEventArgs e)
-        //{
-        //    base.OnStartup(e);
+            var splashScreen = new Views.SplashScreenView.SplashScreen();
+            splashScreen.Show();
 
-        //    ThemeManager.Current.AddTheme(new Theme("CustomDarkRed", "CustomDarkRed", "Dark", "Red", Colors.DarkRed, Brushes.DarkRed, true, false));
-        //    ThemeManager.Current.AddTheme(new Theme("CustomLightRed", "CustomLightRed", "Light", "Red", Colors.DarkRed, Brushes.DarkRed, true, false));
+            var mainWindow = new MainWindow();
+            await PerformInitializationAsync(mainWindow);
+            MainWindow = mainWindow;
+            mainWindow.Show();
 
-        //    ThemeManager.Current.AddTheme(RuntimeThemeGenerator.Current.GenerateRuntimeTheme("Dark", Colors.Red));
-        //    ThemeManager.Current.AddTheme(RuntimeThemeGenerator.Current.GenerateRuntimeTheme("Light", Colors.Red));
-        //}
+            splashScreen.Close();
+        }
+        private async Task PerformInitializationAsync(MainWindow mainWindow)
+        {
 
+            if (mainWindow.DataContext is MainViewModel mainViewModel)
+            {
+                await mainViewModel.InitializeAsync();
+            }
+
+        }
     }
 
 }

src/CodeSnip/MainViewModel.cs

@@ -112,31 +112,13 @@ public MainViewModel(IFlyoutService flyoutService)
             _flyoutService = flyoutService;
             try
             {
-
-                _databaseService.InitializeDatabaseIfNeeded();
-
                 _menuOpenIcon = Application.Current.Resources["MenuOpen"] as Geometry;
                 _menuCloseIcon = Application.Current.Resources["MenuClose"] as Geometry;
                 if (_menuOpenIcon == null || _menuCloseIcon == null)
                 {
                     throw new InvalidOperationException("Icons not found in resources.");
                 }
-                IsLoadSnippetEnabled = !settingsService.LoadOnStartup;
-                ShowEmptyLanguages = settingsService.ShowEmptyLanguages;
-                ShowEmptyCategories = settingsService.ShowEmptyCategories;
 
-                if (settingsService.LoadOnStartup)
-                {
-                    LoadSnippets();
-                    if (settingsService.LastSnippet != null)
-                    {
-                        RestoreSelectedSnippetState(settingsService.LastSnippet);
-                    }
-                }
-                IsFilteringEnabled = settingsService.EnableFiltering;
-                EnableBraceStyleFolding = settingsService.EnableBraceStyleFolding;
-                EnablePythonFolding = settingsService.EnablePythonFolding;
-                EnableXmlFolding = settingsService.EnableXmlFolding;
                 SplitViewOpenPaneLength = settingsService.PanelLength;
                 WindowX = settingsService.WindowX;
                 WindowY = settingsService.WindowY;
@@ -148,6 +130,13 @@ public MainViewModel(IFlyoutService flyoutService)
                 opt.HighlightCurrentLine = settingsService.HighlightLine;
                 opt.IndentationSize = settingsService.IntendationSize;
 
+                IsFilteringEnabled = settingsService.EnableFiltering;
+                EnableBraceStyleFolding = settingsService.EnableBraceStyleFolding;
+                EnablePythonFolding = settingsService.EnablePythonFolding;
+                EnableXmlFolding = settingsService.EnableXmlFolding;
+                ShowEmptyLanguages = settingsService.ShowEmptyLanguages;
+                ShowEmptyCategories = settingsService.ShowEmptyCategories;
+
             }
             catch (InvalidOperationException ex)
             {
@@ -159,6 +148,47 @@ public MainViewModel(IFlyoutService flyoutService)
             }
 
         }
+        public async Task InitializeAsync()
+        {
+            await Task.Run(() => _databaseService.InitializeDatabaseIfNeeded());
+
+            IsLoadSnippetEnabled = !settingsService.LoadOnStartup;
+
+            if (settingsService.LoadOnStartup)
+            {
+                var languages = await Task.Run(() => _databaseService.GetSnippets());
+
+                PopulateLanguagesCollection(languages);
+
+                if (settingsService.LastSnippet != null && settingsService.LoadOnStartup)
+                {
+                    RestoreSelectedSnippetState(settingsService.LastSnippet);
+                }
+            }
+        }
+
+        private void PopulateLanguagesCollection(IEnumerable<Language> languages)
+        {
+            Languages.Clear();
+            foreach (var lang in languages)
+            {
+                bool languageHasAnySnippets = false;
+                foreach (var cat in lang.Categories)
+                {
+                    bool categoryHasSnippets = cat.Snippets.Any();
+                    if (categoryHasSnippets)
+                    {
+                        languageHasAnySnippets = true;
+                    }
+
+                    // A category is visible if the setting is on, OR if it has snippets.
+                    cat.IsVisible = ShowEmptyCategories || categoryHasSnippets;
+                }
+                // A language is visible if the setting is on, OR if it has any snippets.
+                lang.IsVisible = ShowEmptyLanguages || languageHasAnySnippets;
+                Languages.Add(lang);
+            }
+        }
 
         // Call from the MainWindow constructor
         public void InitializeEditor(TextEditor textEditor)
@@ -371,7 +401,7 @@ private void OpenSettings()
                             tmpSnippet.Id);
                     }
                 }
-               
+
                 settingsService.SaveSettings();
             });
         }
@@ -581,24 +611,7 @@ public void OnWindowClosing(CancelEventArgs e)
         public void LoadSnippets()
         {
             var languages = _databaseService.GetSnippets();
-            Languages.Clear();
-            foreach (var lang in languages)
-            {
-                bool languageHasAnySnippets = false;
-                foreach (var cat in lang.Categories)
-                {
-                    bool categoryHasSnippets = cat.Snippets.Any();
-                    if (categoryHasSnippets)
-                    {
-                        languageHasAnySnippets = true;
-                    }
-                    // A category is visible if the setting is on, OR if it has snippets.
-                    cat.IsVisible = ShowEmptyCategories || categoryHasSnippets;
-                }
-                // A language is visible if the setting is on, OR if it has any snippets.
-                lang.IsVisible = ShowEmptyLanguages || languageHasAnySnippets;
-                Languages.Add(lang);
-            }
+            PopulateLanguagesCollection(languages);
         }
 
         private void SaveSettings()

src/CodeSnip/Views/SplashScreenView/SplashScreen.xaml

@@ -0,0 +1,21 @@
+<mah:MetroWindow  x:Class="CodeSnip.Views.SplashScreenView.SplashScreen"
+                 xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
+                 xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+                 xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
+                 xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
+                 xmlns:mah="http://metro.mahapps.com/winfx/xaml/controls"
+                 mc:Ignorable="d"
+                 Height="110" Width="110"
+                 WindowStyle="None"
+                 AllowsTransparency="True"
+                 Background="Transparent"
+                 WindowStartupLocation="CenterScreen"
+                 ShowInTaskbar="False"
+                 Topmost="True"
+                 ShowTitleBar="False" SizeToContent="WidthAndHeight" BorderBrush="Transparent"
+                 ShowCloseButton="False" ShowMaxRestoreButton="False" ShowMinButton="False" >
+    <Grid>
+        <mah:ProgressRing IsActive="True" Width="100" Height="100" IsLarge="True" />
+    </Grid>
+</mah:MetroWindow>
+

src/CodeSnip/Views/SplashScreenView/SplashScreen.xaml.cs

@@ -0,0 +1,12 @@
+using MahApps.Metro.Controls;
+
+namespace CodeSnip.Views.SplashScreenView
+{
+    public partial class SplashScreen : MetroWindow
+    {
+        public SplashScreen()
+        {
+            InitializeComponent();
+        }
+    }
+}