# Tool.IHandler interface

Namespace: [Eto.Forms](https://eto.picoe.ca/api/namespace/eto.forms.md) · Assembly: [Eto](https://eto.picoe.ca/api/assembly/eto.md)

```cs
public interface Tool.IHandler : Widget.IHandler
```

Interface for platform implementations of the [Tool](https://eto.picoe.ca/api/type/eto.forms.tool.md) class.

**Derived types:** [ToolItem.IHandler](https://eto.picoe.ca/api/type/eto.forms.toolitem.ihandler.md)

## Methods

- [OnLoad](https://eto.picoe.ca/api/type/eto.forms.tool.ihandler/onload.md): Called when the tool item is assigned to a control/window
- [OnPreLoad](https://eto.picoe.ca/api/type/eto.forms.tool.ihandler/onpreload.md): Called before the tool item is assigned to a control/window
- [OnUnLoad](https://eto.picoe.ca/api/type/eto.forms.tool.ihandler/onunload.md): Called when the tool item is removed from a control/window

## Inherited Members

- From [Widget.IHandler](https://eto.picoe.ca/api/type/eto.widget.ihandler.md): [ID](https://eto.picoe.ca/api/type/eto.widget.ihandler/id.md), [NativeHandle](https://eto.picoe.ca/api/type/eto.widget.ihandler/nativehandle.md), [Widget](https://eto.picoe.ca/api/type/eto.widget.ihandler/widget.md), [HandleEvent](https://eto.picoe.ca/api/type/eto.widget.ihandler/handleevent.md), [Initialize](https://eto.picoe.ca/api/type/eto.widget.ihandler/initialize.md), [UnhandleEvent](https://eto.picoe.ca/api/type/eto.widget.ihandler/unhandleevent.md)