# OnToolGUI(EditorWindow)

> Use this method to implement a custom editor tool.

## Definition

* **Type:** Method
* **Namespace:** [UnityEditor.EditorTools](/engine/6000.6/script-reference/unityeditor/editortools.md)
* **Assembly:** UnityEditor.CoreModule

```csharp
public virtual void OnToolGUI(EditorWindow window)
```

### Parameters

**** (\[EditorWindow]\(/engine/6000.6/script-reference/unityeditor/editorwindow)): The window that is displaying the custom editor tool.

### Remarks

This method is called for each window where the custom editor tool is active. If the custom editor tool is subscribed to onSceneGUIDelegate, use this method to replace the callback. The onSceneGUIDelegate method is called for every open SceneView.