Merge pull request #3392 from Flow-Launcher/fix_dispatcher_issue

Fix application null exception & Remove unused MainWindowOpacity property

Author: Jack251970

Flow.Launcher/MainWindow.xaml

@@ -24,7 +24,6 @@
     Left="{Binding Settings.WindowLeft, Mode=TwoWay, UpdateSourceTrigger=PropertyChanged}"
     Loaded="OnLoaded"
     LocationChanged="OnLocationChanged"
-    Opacity="{Binding MainWindowOpacity, Mode=OneWay, UpdateSourceTrigger=PropertyChanged}"
     PreviewKeyDown="OnKeyDown"
     PreviewKeyUp="OnKeyUp"
     PreviewMouseMove="OnPreviewMouseMove"

Flow.Launcher/MainWindow.xaml.cs

@@ -111,8 +111,8 @@ private async void OnLoaded(object sender, RoutedEventArgs _)
                 App.API.SaveAppAllSettings();
 
                 // Show Welcome Window
-                var WelcomeWindow = new WelcomeWindow();
-                WelcomeWindow.Show();
+                var welcomeWindow = new WelcomeWindow();
+                welcomeWindow.Show();
             }
 
             // Hide window if need
@@ -241,7 +241,7 @@ private async void OnLoaded(object sender, RoutedEventArgs _)
             };
 
             // QueryTextBox.Text change detection (modified to only work when character count is 1 or higher)
-            QueryTextBox.TextChanged += (sender, e) => UpdateClockPanelVisibility();
+            QueryTextBox.TextChanged += (s, e) => UpdateClockPanelVisibility();
 
             // Detecting ContextMenu.Visibility changes
             DependencyPropertyDescriptor
@@ -351,15 +351,13 @@ private void OnKeyDown(object sender, KeyEventArgs e)
                         _viewModel.LoadContextMenuCommand.Execute(null);
                         e.Handled = true;
                     }
-
                     break;
                 case Key.Left:
                     if (!_viewModel.QueryResultsSelected() && QueryTextBox.CaretIndex == 0)
                     {
                         _viewModel.EscCommand.Execute(null);
                         e.Handled = true;
                     }
-
                     break;
                 case Key.Back:
                     if (specialKeyState.CtrlPressed)
@@ -378,7 +376,6 @@ private void OnKeyDown(object sender, KeyEventArgs e)
                             }
                         }
                     }
-
                     break;
                 default:
                     break;
@@ -864,16 +861,18 @@ private void WindowAnimation()
         private void UpdateClockPanelVisibility()
         {
             if (QueryTextBox == null || ContextMenu == null || History == null || ClockPanel == null)
+            {
                 return;
+            }
 
+            // ✅ Initialize animation length & duration
             var animationLength = _settings.AnimationSpeed switch
             {
                 AnimationSpeeds.Slow => 560,
                 AnimationSpeeds.Medium => 360,
                 AnimationSpeeds.Fast => 160,
                 _ => _settings.CustomAnimationLength
             };
-
             var animationDuration = TimeSpan.FromMilliseconds(animationLength * 2 / 3);
 
             // ✅ Conditions for showing ClockPanel (No query input & ContextMenu, History are closed)
@@ -890,15 +889,21 @@ private void UpdateClockPanelVisibility()
             }
 
             // ✅ 2. When ContextMenu is closed, keep it Hidden if there's text in the query (remember previous state)
-            if (ContextMenu.Visibility != Visibility.Visible && QueryTextBox.Text.Length > 0)
+            else if (QueryTextBox.Text.Length > 0)
             {
                 _viewModel.ClockPanelVisibility = Visibility.Hidden;
                 _viewModel.ClockPanelOpacity = 0.0;
                 return;
             }
 
+            // ✅ Prevent multiple animations
+            if (_isClockPanelAnimating)
+            {
+                return;
+            }
+
             // ✅ 3. When hiding ClockPanel (apply fade-out animation)
-            if ((!shouldShowClock) && _viewModel.ClockPanelVisibility == Visibility.Visible && !_isClockPanelAnimating)
+            if ((!shouldShowClock) && _viewModel.ClockPanelVisibility == Visibility.Visible)
             {
                 _isClockPanelAnimating = true;
 
@@ -920,32 +925,32 @@ private void UpdateClockPanelVisibility()
             }
 
             // ✅ 4. When showing ClockPanel (apply fade-in animation)
-            else if (shouldShowClock && _viewModel.ClockPanelVisibility != Visibility.Visible && !_isClockPanelAnimating)
+            else if (shouldShowClock && _viewModel.ClockPanelVisibility != Visibility.Visible)
             {
                 _isClockPanelAnimating = true;
 
-                Application.Current.Dispatcher.Invoke(() =>
+                _viewModel.ClockPanelVisibility = Visibility.Visible;  // ✅ Set Visibility to Visible first
+
+                var fadeIn = new DoubleAnimation
                 {
-                    _viewModel.ClockPanelVisibility = Visibility.Visible;  // ✅ Set Visibility to Visible first
+                    From = 0.0,
+                    To = 1.0,
+                    Duration = animationDuration,
+                    FillBehavior = FillBehavior.HoldEnd
+                };
 
-                    var fadeIn = new DoubleAnimation
-                    {
-                        From = 0.0,
-                        To = 1.0,
-                        Duration = animationDuration,
-                        FillBehavior = FillBehavior.HoldEnd
-                    };
-
-                    fadeIn.Completed += (s, e) => _isClockPanelAnimating = false;
-                    ClockPanel.BeginAnimation(OpacityProperty, fadeIn);
-                }, DispatcherPriority.Render);
+                fadeIn.Completed += (s, e) => _isClockPanelAnimating = false;
+
+                ClockPanel.BeginAnimation(OpacityProperty, fadeIn);
             }
         }
 
         private static double GetOpacityFromStyle(Style style, double defaultOpacity = 1.0)
         {
             if (style == null)
+            {
                 return defaultOpacity;
+            }
 
             foreach (Setter setter in style.Setters.Cast<Setter>())
             {
@@ -961,7 +966,9 @@ private static double GetOpacityFromStyle(Style style, double defaultOpacity = 1
         private static Thickness GetThicknessFromStyle(Style style, Thickness defaultThickness)
         {
             if (style == null)
+            {
                 return defaultThickness;
+            }
 
             foreach (Setter setter in style.Setters.Cast<Setter>())
             {

Flow.Launcher/ViewModel/MainViewModel.cs

@@ -753,8 +753,7 @@ private ResultsViewModel SelectedResults
 
         public Visibility ProgressBarVisibility { get; set; }
         public Visibility MainWindowVisibility { get; set; }
-        public double MainWindowOpacity { get; set; } = 1;
-
+        
         // This is to be used for determining the visibility status of the mainwindow instead of MainWindowVisibility
         // because it is more accurate and reliable representation than using Visibility as a condition check
         public bool MainWindowVisibilityStatus { get; set; } = true;
@@ -1454,9 +1453,11 @@ public bool ShouldIgnoreHotkeys()
 
         public void Show()
         {
+            // Invoke on UI thread
             Application.Current.Dispatcher.Invoke(() =>
             {
-                if (Application.Current.MainWindow is MainWindow mainWindow)
+                // When application is exitting, the Application.Current will be null
+                if (Application.Current?.MainWindow is MainWindow mainWindow)
                 {
                     // 📌 Remove DWM Cloak (Make the window visible normally)
                     Win32Helper.DWMSetCloakForWindow(mainWindow, false);
@@ -1481,10 +1482,10 @@ public void Show()
 
             // Update WPF properties
             MainWindowVisibility = Visibility.Visible;
-            MainWindowOpacity = 1;
             MainWindowVisibilityStatus = true;
             VisibilityChanged?.Invoke(this, new VisibilityChangedEventArgs { IsVisible = true });
 
+            // Switch keyboard layout
             if (StartWithEnglishMode)
             {
                 Win32Helper.SwitchToEnglishKeyboardLayout(true);
@@ -1527,9 +1528,11 @@ public async void Hide()
                     break;
             }
 
+            // Invoke on UI thread
             Application.Current.Dispatcher.Invoke(() =>
             {
-                if (Application.Current.MainWindow is MainWindow mainWindow)
+                // When application is exitting, the Application.Current will be null
+                if (Application.Current?.MainWindow is MainWindow mainWindow)
                 {
                     // Set clock and search icon opacity
                     var opacity = Settings.UseAnimation ? 0.0 : 1.0;
@@ -1549,6 +1552,7 @@ public async void Hide()
                 }
             }, DispatcherPriority.Render);
 
+            // Switch keyboard layout
             if (StartWithEnglishMode)
             {
                 Win32Helper.RestorePreviousKeyboardLayout();
@@ -1558,7 +1562,6 @@ public async void Hide()
             await Task.Delay(50);
 
             // Update WPF properties
-            //MainWindowOpacity = 0;
             MainWindowVisibilityStatus = false;
             MainWindowVisibility = Visibility.Collapsed;
             VisibilityChanged?.Invoke(this, new VisibilityChangedEventArgs { IsVisible = false });