Fix incomplete functionality, nullable warnings, and async issues

Incomplete functionality fixes:
- SkiaEditor: Wire up Completed event to fire on focus lost
- X11InputMethodService: Remove unused _commitCallback field
- SkiaWebView: Set _isProperlyReparented when reparenting succeeds,
  use _lastMainX/_lastMainY to track main window position,
  add _isEmbedded guard to prevent double embedding

Nullable reference fixes:
- Easing: Reorder BounceOut before BounceIn (static init order)
- GestureManager: Use local command variable instead of re-accessing
- SkiaShell: Handle null Title with ?? operator
- GLibNative: Use null! for closure pattern
- LinuxProgramHost: Default title if null
- SkiaWebView.LoadHtml: Add null/empty check for html
- SystemThemeService: Initialize Colors with default values
- DeviceDisplayService/AppInfoService: Use var for nullable env vars
- EmailService: Add null check for message parameter

Async fixes:
- SkiaImage: Use _ = for fire-and-forget async calls
- SystemTrayService: Convert async method without await to sync Task

Reduces warnings from 156 to 133 (remaining are P/Invoke structs
and obsolete MAUI API usage)

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

Easing.cs

@@ -22,8 +22,7 @@ public class Easing
     public static readonly Easing CubicInOut = new(v =>
         v < 0.5 ? 4.0 * v * v * v : 1.0 - Math.Pow(-2.0 * v + 2.0, 3.0) / 2.0);
 
-    public static readonly Easing BounceIn = new(v => 1.0 - BounceOut.Ease(1.0 - v));
+    // BounceOut must be declared before BounceIn since BounceIn references it
-
     public static readonly Easing BounceOut = new(v =>
     {
         const double n1 = 7.5625;
@@ -38,6 +37,8 @@ public class Easing
         return n1 * (v -= 2.625 / d1) * v + 0.984375;
     });
 
+    public static readonly Easing BounceIn = new(v => 1.0 - BounceOut.Ease(1.0 - v));
+
     public static readonly Easing SpringIn = new(v => v * v * (2.70158 * v - 1.70158));
 
     public static readonly Easing SpringOut = new(v =>

Handlers/GestureManager.cs

@@ -188,7 +188,7 @@ public static class GestureManager
             if (command != null && command.CanExecute(tapRecognizer.CommandParameter))
             {
                 Console.WriteLine("[GestureManager] Executing Command");
-                tapRecognizer.Command.Execute(tapRecognizer.CommandParameter);
+                command.Execute(tapRecognizer.CommandParameter);
             }
             result = true;
         }

Hosting/LinuxProgramHost.cs

@@ -46,7 +46,7 @@ public static class LinuxProgramHost
         ParseCommandLineOptions(args, options);
 
         // Initialize GTK for WebView support
-        GtkHostService.Instance.Initialize(options.Title, options.Width, options.Height);
+        GtkHostService.Instance.Initialize(options.Title ?? "MAUI Application", options.Width, options.Height);
         Console.WriteLine("[LinuxProgramHost] GTK initialized for WebView support");
 
         // Create Linux application

Native/GLibNative.cs

@@ -28,7 +28,7 @@ public static class GLibNative
 
     public static uint IdleAdd(Func<bool> callback)
     {
-        GSourceFunc wrapper = null;
+        GSourceFunc wrapper = null!;
         wrapper = delegate
         {
             bool flag = false;
@@ -58,7 +58,7 @@ public static class GLibNative
 
     public static uint TimeoutAdd(uint intervalMs, Func<bool> callback)
     {
-        GSourceFunc wrapper = null;
+        GSourceFunc wrapper = null!;
         wrapper = delegate
         {
             bool flag = false;

Services/AppInfoService.cs

@@ -41,7 +41,7 @@ public class AppInfoService : IAppInfo
         {
             try
             {
-                string environmentVariable = Environment.GetEnvironmentVariable("GTK_THEME");
+                var environmentVariable = Environment.GetEnvironmentVariable("GTK_THEME");
                 if (!string.IsNullOrEmpty(environmentVariable) && environmentVariable.Contains("dark", StringComparison.OrdinalIgnoreCase))
                 {
                     return AppTheme.Dark;

Services/DeviceDisplayService.cs

@@ -73,13 +73,13 @@ public class DeviceDisplayService : IDeviceDisplay
 
     private double GetScaleFactor()
     {
-        string gdkScale = Environment.GetEnvironmentVariable("GDK_SCALE");
+        var gdkScale = Environment.GetEnvironmentVariable("GDK_SCALE");
         if (!string.IsNullOrEmpty(gdkScale) && double.TryParse(gdkScale, out var result))
         {
             return result;
         }
 
-        string qtScale = Environment.GetEnvironmentVariable("QT_SCALE_FACTOR");
+        var qtScale = Environment.GetEnvironmentVariable("QT_SCALE_FACTOR");
         if (!string.IsNullOrEmpty(qtScale) && double.TryParse(qtScale, out result))
         {
             return result;

Services/EmailService.cs

@@ -69,6 +69,7 @@ public class EmailService : IEmail
     private static string BuildMailtoUri(EmailMessage? message)
     {
         var sb = new StringBuilder("mailto:");
+        if (message == null) return sb.ToString();
 
         // Add recipients
         if (message.To?.Count > 0)

Services/SystemThemeService.cs

@@ -56,7 +56,19 @@ public class SystemThemeService
     /// <summary>
     /// System colors based on the current theme.
     /// </summary>
-    public SystemColors Colors { get; private set; }
+    public SystemColors Colors { get; private set; } = new SystemColors
+    {
+        Background = SKColors.White,
+        Surface = new SKColor(0xF5, 0xF5, 0xF5),
+        Primary = new SKColor(0x21, 0x96, 0xF3),
+        OnPrimary = SKColors.White,
+        Text = new SKColor(0x21, 0x21, 0x21),
+        TextSecondary = new SKColor(0x75, 0x75, 0x75),
+        Border = new SKColor(0xE0, 0xE0, 0xE0),
+        Divider = new SKColor(0xE0, 0xE0, 0xE0),
+        Error = new SKColor(0xF4, 0x43, 0x36),
+        Success = new SKColor(0x4C, 0xAF, 0x50)
+    };
 
     private FileSystemWatcher? _settingsWatcher;
 

Services/SystemTrayService.cs

@@ -101,7 +101,7 @@ public class SystemTrayService : IDisposable
         _ = ShowAsync();
     }
 
-    private async Task<bool> TryYadTray()
+    private Task<bool> TryYadTray()
     {
         try
         {
@@ -118,7 +118,7 @@ public class SystemTrayService : IDisposable
             };
 
             _trayProcess = Process.Start(startInfo);
-            if (_trayProcess == null) return false;
+            if (_trayProcess == null) return Task.FromResult(false);
 
             // Start reading output for menu clicks
             _ = Task.Run(async () =>
@@ -137,11 +137,11 @@ public class SystemTrayService : IDisposable
                 catch { }
             });
 
-            return true;
+            return Task.FromResult(true);
         }
         catch
         {
-            return false;
+            return Task.FromResult(false);
         }
     }
 

Services/X11InputMethodService.cs

@@ -27,7 +27,6 @@ public class X11InputMethodService : IInputMethodService, IDisposable
     private XIMProc? _preeditDoneCallback;
     private XIMProc? _preeditDrawCallback;
     private XIMProc? _preeditCaretCallback;
-    private XIMProc? _commitCallback;
 
     public bool IsActive => _isActive;
     public string PreEditText => _preEditText;

Views/SkiaEditor.cs

@@ -982,6 +982,7 @@ public class SkiaEditor : SkiaView
     {
         base.OnFocusLost();
         SkiaVisualStateManager.GoToState(this, SkiaVisualStateManager.CommonStates.Normal);
+        Completed?.Invoke(this, EventArgs.Empty);
     }
 
     #region Selection and Clipboard

Views/SkiaImage.cs

@@ -84,7 +84,7 @@ public class SkiaImage : SkiaView
                 !_pendingSvgReload)
             {
                 _pendingSvgReload = true;
-                ReloadSvgDebounced();
+                _ = ReloadSvgDebounced();
             }
         }
     }
@@ -427,7 +427,7 @@ public class SkiaImage : SkiaView
                 {
                     _lastArrangedBounds = bounds;
                     Console.WriteLine($"[SkiaImage] Arrange detected larger bounds: {width}x{height} vs loaded {_svgLoadedWidth}x{_svgLoadedHeight}");
-                    LoadSvgAtSizeAsync(_currentFilePath, width, height);
+                    _ = LoadSvgAtSizeAsync(_currentFilePath, width, height);
                 }
             }
         }

Views/SkiaShell.cs

@@ -693,7 +693,7 @@ public class SkiaShell : SkiaLayoutView
         }
 
         SetCurrentContent(root.Content);
-        Title = root.Title;
+        Title = root.Title ?? string.Empty;
         Invalidate();
     }
 

Views/SkiaWebView.cs

@@ -759,6 +759,11 @@ public class SkiaWebView : SkiaView
     public void LoadHtml(string html, string? baseUrl = null)
     {
         Console.WriteLine($"[WebView] LoadHtml called, html length: {html?.Length ?? 0}");
+        if (string.IsNullOrEmpty(html))
+        {
+            Console.WriteLine("[WebView] Cannot load HTML - html is null or empty");
+            return;
+        }
         if (!_isInitialized) Initialize();
         if (_webView == IntPtr.Zero || _webkitLoadHtml == null)
         {
@@ -869,6 +874,7 @@ public class SkiaWebView : SkiaView
 
     public void ShowNativeWindow()
     {
+        if (_isEmbedded) return; // Already embedded
         if (!_isInitialized) Initialize();
         if (_gtkWindow == IntPtr.Zero) return;
 
@@ -918,7 +924,15 @@ public class SkiaWebView : SkiaView
         if (gdkWindow != IntPtr.Zero)
         {
             _gtkX11Window = gdk3_x11_window_get_xid(gdkWindow);
-            Console.WriteLine($"[WebView] GTK X11 window: {_gtkX11Window}");
+            if (_gtkX11Window != IntPtr.Zero)
+            {
+                _isProperlyReparented = true;
+                Console.WriteLine($"[WebView] GTK X11 window: {_gtkX11Window} (reparented successfully)");
+            }
+            else
+            {
+                Console.WriteLine($"[WebView] GTK X11 window: failed to get XID");
+            }
         }
 
         PositionUsingGtk();
@@ -1073,13 +1087,20 @@ public class SkiaWebView : SkiaView
         }
         catch { }
 
-        int offsetX = 0, offsetY = 0;
+        // Track main window position changes
-        int screenX = destX + (int)Bounds.Left - offsetX;
+        bool mainWindowMoved = destX != _lastMainX || destY != _lastMainY;
-        int screenY = destY + (int)Bounds.Top - offsetY;
+        if (mainWindowMoved)
+        {
+            _lastMainX = destX;
+            _lastMainY = destY;
+        }
+
+        int screenX = destX + (int)Bounds.Left;
+        int screenY = destY + (int)Bounds.Top;
         int width = Math.Max(100, (int)Bounds.Width);
         int height = Math.Max(100, (int)Bounds.Height);
 
-        if (Math.Abs(screenX - _lastPosX) > 2 || Math.Abs(screenY - _lastPosY) > 2 ||
+        if (mainWindowMoved || Math.Abs(screenX - _lastPosX) > 2 || Math.Abs(screenY - _lastPosY) > 2 ||
             Math.Abs(width - _lastWidth) > 2 || Math.Abs(height - _lastHeight) > 2)
         {
             Console.WriteLine($"[WebView] Move to ({screenX}, {screenY}), size ({width}x{height}), mainWin=({destX},{destY}), bounds=({Bounds.Left},{Bounds.Top})");