Save open files on window focus loss

src/SharpIDE.Godot/IdeWindow.cs

@@ -27,6 +27,7 @@ public partial class IdeWindow : Control
         MSBuildLocator.RegisterDefaults();
         GodotServiceDefaults.AddServiceDefaults();
         Singletons.AppState = AppStateLoader.LoadAppStateFromConfigFile();
+        GetWindow().FocusExited += OnFocusExited;
         //GetWindow().SetMinSize(new Vector2I(1152, 648));
         Callable.From(() => PickSolution(true)).CallDeferred();
     }
@@ -42,6 +43,11 @@ public partial class IdeWindow : Control
         // PrintOrphanNodes();
     }
     
+    private void OnFocusExited()
+    {
+        _ = Task.GodotRun(async () => await Singletons.FileManager.SaveAllOpenFilesAsync());
+    }
+    
     public void PickSolution(bool fullscreen = false)
     {
         if (_slnPicker is not null) throw new InvalidOperationException("Solution picker is already active");