> ## Documentation Index
> Fetch the complete documentation index at: https://docs.abbyy.com/llms.txt
> Use this file to discover all available pages before exploring further.

# MouseButtonEnum

> MouseButtonEnum enumeration in ABBYY FineReader Engine Visual Components on Windows — MouseButtonEnum enumeration constants are used to denote mouse buttons.

<Warning>
  Visual Components are implemented in FRE for Windows.
</Warning>

MouseButtonEnum enumeration constants are used to denote mouse buttons.

```
typedef enum {
 MBU_LeftButton,
 MBU_MiddleButton,
 MBU_RightButton
} MouseButtonEnum;
```

## Elements

| Name                | Description          |
| ------------------- | -------------------- |
| MBU\\\_LeftButton   | Left mouse button.   |
| MBU\\\_MiddleButton | Middle mouse button. |
| MBU\\\_RightButton  | Right mouse button.  |

## Used in

[IInputEvents::OnMouseButtonDown](/fine-reader/engine/visual-components-reference/iinputevents/onmousebuttondown-method)

[IInputEvents::OnMouseButtonUp](/fine-reader/engine/visual-components-reference/iinputevents/onmousebuttonup-method)