Support smooth scroll

Author: Jack251970

Flow.Launcher/ReleaseNotesWindow.xaml

@@ -166,22 +166,32 @@
                     <cc:HyperLink x:Name="SeeMore" Text="{DynamicResource seeMoreReleaseNotes}" />
                 </Grid>
 
-                <mdxam:MarkdownScrollViewer
-                    x:Name="MarkdownViewer"
+                <!--  Do not use scroll function of MarkdownViewer because it does not support smooth scroll  -->
+                <ScrollViewer
+                    x:Name="MarkdownScrollViewer"
                     Grid.Row="2"
                     Grid.Column="0"
                     Grid.ColumnSpan="5"
                     Width="500"
-                    Height="500"
-                    Margin="15 0 20 0"
-                    ClickAction="SafetyDisplayWithRelativePath"
-                    Loaded="MarkdownViewer_Loaded"
-                    Plugins="{StaticResource MdXamlPlugins}"
-                    Visibility="Collapsed" />
+                    Height="500">
+                    <mdxam:MarkdownScrollViewer
+                        x:Name="MarkdownViewer"
+                        Margin="15 0 20 0"
+                        HorizontalAlignment="Stretch"
+                        VerticalAlignment="Stretch"
+                        ClickAction="SafetyDisplayWithRelativePath"
+                        HorizontalScrollBarVisibility="Disabled"
+                        Loaded="MarkdownViewer_Loaded"
+                        MouseWheel="MarkdownViewer_MouseWheel"
+                        Plugins="{StaticResource MdXamlPlugins}"
+                        PreviewMouseWheel="MarkdownViewer_PreviewMouseWheel"
+                        VerticalScrollBarVisibility="Disabled"
+                        Visibility="Collapsed" />
+                </ScrollViewer>
 
                 <!--  This Grid is for display progress ring and refresh button.  -->
                 <!--  And it is also for changing the size of the MarkdownViewer.  -->
-                <!--  Because VerticalAlignment="Stretch" can cause size issue with MarkdownViewer.  -->
+                <!--  Because VerticalAlignment="Stretch" can cause size issue with MarkdownScrollViewer.  -->
                 <Grid
                     Grid.Row="2"
                     Grid.Column="0"

Flow.Launcher/ReleaseNotesWindow.xaml.cs

@@ -24,6 +24,25 @@ public ReleaseNotesWindow()
             ModernWpf.ThemeManager.Current.ActualApplicationThemeChanged += ThemeManager_ActualApplicationThemeChanged;
         }
 
+        private void ThemeManager_ActualApplicationThemeChanged(ModernWpf.ThemeManager sender, object args)
+        {
+            Application.Current.Dispatcher.Invoke(() =>
+            {
+                if (ModernWpf.ThemeManager.Current.ActualApplicationTheme == ModernWpf.ApplicationTheme.Light)
+                {
+                    MarkdownViewer.MarkdownStyle = (Style)Application.Current.Resources["DocumentStyleGithubLikeLight"];
+                    MarkdownViewer.Foreground = Brushes.Black;
+                    MarkdownViewer.Background = Brushes.White;
+                }
+                else
+                {
+                    MarkdownViewer.MarkdownStyle = (Style)Application.Current.Resources["DocumentStyleGithubLikeDark"];
+                    MarkdownViewer.Foreground = Brushes.White;
+                    MarkdownViewer.Background = Brushes.Black;
+                }
+            });
+        }
+
         #region Window Events
 
         private void Window_Loaded(object sender, RoutedEventArgs e)
@@ -162,6 +181,8 @@ private sealed class GitHubReleaseInfo
 
         #endregion
 
+        #region Control Events
+
         private void MarkdownViewer_Loaded(object sender, RoutedEventArgs e)
         {
             RefreshMarkdownViewer();
@@ -196,29 +217,36 @@ private async void RefreshMarkdownViewer()
             });
         }
 
-        private void ThemeManager_ActualApplicationThemeChanged(ModernWpf.ThemeManager sender, object args)
+        private void Grid_SizeChanged(object sender, SizeChangedEventArgs e)
         {
-            Application.Current.Dispatcher.Invoke(() =>
-            {
-                if (ModernWpf.ThemeManager.Current.ActualApplicationTheme == ModernWpf.ApplicationTheme.Light)
-                {
-                    MarkdownViewer.MarkdownStyle = (Style)Application.Current.Resources["DocumentStyleGithubLikeLight"];
-                    MarkdownViewer.Foreground = Brushes.Black;
-                    MarkdownViewer.Background = Brushes.White;
-                }
-                else
-                {
-                    MarkdownViewer.MarkdownStyle = (Style)Application.Current.Resources["DocumentStyleGithubLikeDark"];
-                    MarkdownViewer.Foreground = Brushes.White;
-                    MarkdownViewer.Background = Brushes.Black;
-                }
-            });
+            MarkdownScrollViewer.Height = e.NewSize.Height;
+            MarkdownScrollViewer.Width = e.NewSize.Width;
         }
 
-        private void Grid_SizeChanged(object sender, SizeChangedEventArgs e)
+        private void MarkdownViewer_MouseWheel(object sender, MouseWheelEventArgs e)
         {
-            MarkdownViewer.Height = e.NewSize.Height;
-            MarkdownViewer.Width = e.NewSize.Width;
+            RaiseMouseWheelEvent(sender, e);
         }
+
+        private void MarkdownViewer_PreviewMouseWheel(object sender, MouseWheelEventArgs e)
+        {
+            RaiseMouseWheelEvent(sender, e);
+        }
+
+        private void RaiseMouseWheelEvent(object sender, MouseWheelEventArgs e)
+        {
+            e.Handled = true; // Prevent the inner control from handling the event
+
+            var eventArg = new MouseWheelEventArgs(e.MouseDevice, e.Timestamp, e.Delta)
+            {
+                RoutedEvent = UIElement.MouseWheelEvent,
+                Source = sender
+            };
+
+            // Raise the event on the parent ScrollViewer
+            MarkdownScrollViewer.RaiseEvent(eventArg);
+        }
+
+        #endregion
     }
 }