The Ribbon Gallery item enables to perform specific actions by displaying a collection of related items, including icons, content, or images.
In this sample, the gallery item is added to showcase a collection of items with content using gallerySettings property with the defined type as RibbonItemType.Gallery. Each collection can be grouped using groups property with defined group name using header property.
Each item's content is added using content property, and its customization using itemWidth, itemHeight, and cssClass properties.