Polish AmiReel UI and improve render workflow

MainWindow.xaml.cs

@@ -16,6 +16,7 @@ public partial class MainWindow : Window
     private readonly ObservableCollection<string> _inputs = [];
     private readonly AppSettings _loadedSettings;
     private CancellationTokenSource? _renderCancellation;
+    private string? _lastRenderedFile;
 
     public MainWindow()
     {
@@ -26,6 +27,7 @@ public partial class MainWindow : Window
         EndCardBox.Text = _loadedSettings.EndCardPath;
         FfmpegPathBox.Text = _loadedSettings.FfmpegPath;
         FfprobePathBox.Text = _loadedSettings.FfprobePath;
+        PreviewPlayerPathBox.Text = _loadedSettings.PreviewPlayerPath;
         TrimBox.Text = _loadedSettings.TrimStart;
         FadeBox.Text = _loadedSettings.FadeSeconds;
         HoldBox.Text = _loadedSettings.EndCardHoldSeconds;
@@ -70,6 +72,12 @@ public partial class MainWindow : Window
         if (dialog.ShowDialog(this) == true) FfprobePathBox.Text = dialog.FileName;
     }
 
+    private void BrowsePreviewPlayer_Click(object sender, RoutedEventArgs e)
+    {
+        OpenFileDialog dialog = new() { Filter = "Video player (*.exe)|*.exe|All files|*.*" };
+        if (dialog.ShowDialog(this) == true) PreviewPlayerPathBox.Text = dialog.FileName;
+    }
+
     private void OpenSettings_Click(object sender, RoutedEventArgs e) => SettingsOverlay.Visibility = Visibility.Visible;
 
     private void CloseSettings_Click(object sender, RoutedEventArgs e)
@@ -89,7 +97,9 @@ public partial class MainWindow : Window
             _renderCancellation = new CancellationTokenSource();
             Progress<RenderProgress> progress = new(UpdateProgress);
             await new RenderPipeline().RenderAsync(settings, progress, AppendLog, _renderCancellation.Token);
+            _lastRenderedFile = Path.Combine(settings.OutputDirectory, settings.OutputName + "_final.mp4");
             OpenOutputButton.IsEnabled = true;
+            PreviewRenderedButton.IsEnabled = File.Exists(_lastRenderedFile);
             MessageBox.Show(this, "The AmiReel render completed successfully.", "Render complete",
                 MessageBoxButton.OK, MessageBoxImage.Information);
         }
@@ -140,6 +150,27 @@ public partial class MainWindow : Window
             Process.Start(new ProcessStartInfo("explorer.exe", OutputFolderBox.Text) { UseShellExecute = true });
     }
 
+    private void PreviewSource_Click(object sender, RoutedEventArgs e)
+    {
+        if (InputList.SelectedItem is string path)
+            OpenPreview(path);
+    }
+
+    private void PreviewRendered_Click(object sender, RoutedEventArgs e)
+    {
+        if (!string.IsNullOrWhiteSpace(_lastRenderedFile) && File.Exists(_lastRenderedFile))
+            OpenPreview(_lastRenderedFile);
+    }
+
+    private void InputList_SelectionChanged(object sender, SelectionChangedEventArgs e)
+        => PreviewSourceButton.IsEnabled = InputList.SelectedItem is string;
+
+    private void InputList_MouseDoubleClick(object sender, System.Windows.Input.MouseButtonEventArgs e)
+    {
+        if (InputList.SelectedItem is string path)
+            OpenPreview(path);
+    }
+
     private void SetRendering(bool rendering)
     {
         RenderButton.IsEnabled = !rendering;
@@ -187,6 +218,7 @@ public partial class MainWindow : Window
             EndCardBox.Text.Trim(),
             FfmpegPathBox.Text.Trim(),
             FfprobePathBox.Text.Trim(),
+            PreviewPlayerPathBox.Text.Trim(),
             SelectedTheme(),
             SelectedEncoder(),
             TrimBox.Text.Trim(),
@@ -195,6 +227,42 @@ public partial class MainWindow : Window
             IntervalBox.Text.Trim()));
     }
 
+    private void OpenPreview(string mediaPath)
+    {
+        if (!File.Exists(mediaPath))
+        {
+            MessageBox.Show(this, "The selected media file was not found.", "Preview unavailable",
+                MessageBoxButton.OK, MessageBoxImage.Warning);
+            return;
+        }
+
+        string playerPath = PreviewPlayerPathBox.Text.Trim();
+
+        try
+        {
+            if (!string.IsNullOrWhiteSpace(playerPath))
+            {
+                if (!File.Exists(playerPath))
+                    throw new FileNotFoundException("Configured preview player was not found.", playerPath);
+
+                ProcessStartInfo customPlayer = new()
+                {
+                    FileName = playerPath,
+                    UseShellExecute = false
+                };
+                customPlayer.ArgumentList.Add(mediaPath);
+                Process.Start(customPlayer);
+                return;
+            }
+
+            Process.Start(new ProcessStartInfo(mediaPath) { UseShellExecute = true });
+        }
+        catch (Exception exception)
+        {
+            MessageBox.Show(this, exception.Message, "Preview failed", MessageBoxButton.OK, MessageBoxImage.Error);
+        }
+    }
+
     private string SelectedTheme() => ((ComboBoxItem)ThemeBox.SelectedItem).Tag!.ToString()!;
     private string SelectedEncoder() => ((ComboBoxItem)EncoderBox.SelectedItem).Tag!.ToString()!;