# WinUI RibbonView Events Overview

This topic covers the specific events exposed by the **RadRibbonView** control and its sub elements. The events are first grouped by control and then by their general purpose.

## RadRibbonView

**RadRibbonView** provides a couple of useful events that can be used for customization purposes.

* **ToolBarPositionChanged**: Occurs when the location of the toolbar has changed. The type of the passed event arguments is **RadRoutedEventArgs**.

* **CollapsedChanged**: Occurs when the ribbon bar collapsed state has changed. The type of the passed event arguments is **RadRoutedEventArgs**.

* **PreviewMinimizedChanged**: Occurs before ribbon bar minimized state has changed. The type of the passed event arguments is **RadRoutedEventArgs**.

* **MinimizedChanged**: Occurs when ribbon bar minimized state has changed. The type of the passed event arguments is **RadRoutedEventArgs**.

* **MinimizedPopupOpenStateChanged**: Occurs when ribbon bar minimized popup open state has changed. The type of the passed event arguments is **RadRoutedEventArgs**.

* **ApplicationButtonDoubleClick**: Occurs when the user double clicks on the application button. The type of the passed event arguments is **RadRoutedEventArgs**.

* **BackstageOpenStateChanged**: Occurs when the backstage changes its open state. The type of the passed event arguments is **RadRoutedEventArgs**.

* **HelpRequested**: Occurs when the user clicks on the help button. The type of the passed event arguments is **RadRoutedEventArgs**.

* **PreviewPopupOpened**: Occurs when the Popup is opening.

* **PopupOpened**: Occurs when the Popup is opened.

* **LayoutModeChanged**: Occurs when the ribbon view layout mode has changed. The type of the passed event arguments is **RadRoutedEventArgs**.

## Selection

* **PreviewSelectionChanged**: Occurs when the selected tab is going to be changed. The type of the passed event arguments is **RadSelectionChangedEventArgs**.

* **SelectionChanged**: Occurs when the selected tab has changed. The type of the passed event arguments is **RadSelectionChangedEventArgs**.

> tip You could **cancel** the selection process by setting the **RadSelectionChangedEventArgs**'s **Handled** property to **True** in the **PreviewSelectionChanged** event handler.

> tip When your application is started the **PreviewSelectionChanged** and **SelectionChanged** events are always raised.

## RadGallery

* **ActivatePreview**: Occurs when the mouse cursor is over a gallery item. The type of the passed event arguments is **RadRoutedEventArgs**.

* **DeactivatePreview**: Occurs when the mouse cursor leaves the gallery item. The type of the passed event arguments is **RadRoutedEventArgs**.

> When a preview should be activated for a gallery item, the lifecycle of the raised events is:
>
> * **ActivatePreview**
> * **DeactivatePreview**

## RadRibbonGallery

* **IsOpenChanged**: Occurs when **IsOpen** property has changed. The type of the passed event arguments is **RadRoutedEventArgs**.

## RadRibbonGroup

* **LaunchDialog**: Occurs when ribbon bar collapsed state has changed. The type of the passed event arguments is **RadRoutedEventArgs**.