UnityImageProcessing_Package/Editor/Scripts/Editor/Windows/ImageProcessingGraphEditorWindow.cs

using System;
using UnityEditor;
using UnityEditor.Experimental.GraphView;
using UnityEngine;

namespace ImageProcessingGraph.Editor.Windows
{
    public class ImageProcessingGraphEditorWindow : EditorWindow
    {
        [SerializeField] private ImageProcessingGraphAsset currentGraph;
        [SerializeField] private SerializedObject serializedObject;
        [SerializeField] private ImageProcessingGraphViewWindow currentView;
        public ImageProcessingGraphAsset CurrentGraph => currentGraph;

        public static void Open(ImageProcessingGraphAsset asset)
        {
            var existingWindows = Resources.FindObjectsOfTypeAll<ImageProcessingGraphEditorWindow>();
            foreach (var w in existingWindows)
            {
                if (w.CurrentGraph == asset)
                {
                    w.Focus(); // 👁 focus the OG window
                    return;
                }
            }

            var window = CreateWindow<ImageProcessingGraphEditorWindow>(typeof(SceneView));
            window.titleContent = new GUIContent($"{asset.name}",
                EditorGUIUtility.ObjectContent(null, typeof(ImageProcessingGraphAsset)).image);
            window.Load(asset);
            window.Focus();
        }



        void OnEnable()
        {
            if(currentGraph != null)
                DrawGraph();
        }

        private void OnGUI()
        {
            if (currentGraph != null)
            {
                if(EditorUtility.IsDirty(currentGraph))
                    this.hasUnsavedChanges = true;
                else
                    this.hasUnsavedChanges = false;
            }
        }

        public void Load(ImageProcessingGraphAsset asset)
        {
            currentGraph = asset;
            DrawGraph();
        }

        public void DrawGraph()
        {
            serializedObject = new SerializedObject(currentGraph);
            currentView = new ImageProcessingGraphViewWindow(serializedObject, this);
            currentView.graphViewChanged += OnChange;
            rootVisualElement.Add(currentView);
        }

        private GraphViewChange OnChange(GraphViewChange graphviewchange)
        {
            EditorUtility.SetDirty(currentGraph);
            return graphviewchange;
        }
    }
}