You're breathtaking!

Source/Editor/CustomEditorWindow.cs

@@ -0,0 +1,102 @@
+// Copyright (c) 2012-2020 Wojciech Figat. All rights reserved.
+
+using FlaxEditor.CustomEditors;
+using FlaxEditor.Windows;
+using FlaxEngine.GUI;
+using FlaxEngine;
+using DockState = FlaxEditor.GUI.Docking.DockState;
+
+namespace FlaxEditor
+{
+    /// <summary>
+    /// Base class for custom editor window that can create custom GUI layout and expose various functionalities to the user.
+    /// </summary>
+    /// <seealso cref="FlaxEditor.CustomEditors.CustomEditor" />
+    public abstract class CustomEditorWindow : CustomEditor
+    {
+        private class Win : EditorWindow
+        {
+            private readonly CustomEditorPresenter _presenter;
+            private CustomEditorWindow _customEditor;
+
+            public Win(CustomEditorWindow customEditor)
+            : base(Editor.Instance, false, ScrollBars.Vertical)
+            {
+                Title = customEditor.GetType().Name;
+                _customEditor = customEditor;
+
+                _presenter = new CustomEditorPresenter(null);
+                _presenter.Panel.Parent = this;
+
+                Set(customEditor);
+            }
+
+            private void Set(CustomEditorWindow value)
+            {
+                _customEditor = value;
+                _presenter.Select(value);
+                _presenter.OverrideEditor = value;
+            }
+
+            /// <inheritdoc />
+            protected override void OnShow()
+            {
+                base.OnShow();
+
+                _presenter.BuildLayout();
+            }
+
+            /// <inheritdoc />
+            protected override void OnClose()
+            {
+                Set(null);
+
+                base.OnClose();
+            }
+        }
+
+        private readonly Win _win;
+
+        /// <summary>
+        /// Gets the editor window.
+        /// </summary>
+        public EditorWindow Window => _win;
+
+        /// <summary>
+        /// Initializes a new instance of the <see cref="CustomEditorWindow"/> class.
+        /// </summary>
+        protected CustomEditorWindow()
+        {
+            _win = new Win(this);
+            ScriptsBuilder.ScriptsReloadBegin += OnScriptsReloadBegin;
+        }
+
+        /// <summary>
+        /// Finalizes an instance of the <see cref="CustomEditorWindow"/> class.
+        /// </summary>
+        ~CustomEditorWindow()
+        {
+            ScriptsBuilder.ScriptsReloadBegin -= OnScriptsReloadBegin;
+        }
+
+        private void OnScriptsReloadBegin()
+        {
+            // Skip if window type is not from game script assembly (eg. plugin code)
+            var type = GetType();
+            if (!FlaxEngine.Scripting.IsTypeFromGameScripts(type))
+                return;
+
+            Editor.Instance.Windows.AddToRestore(this);
+            Window.Close();
+        }
+
+        /// <summary>
+        /// Shows the window.
+        /// </summary>
+        /// <param name="state">Initial window state.</param>
+        public void Show(DockState state = DockState.Float)
+        {
+            _win.Show(state);
+        }
+    }
+}