Displaying menus with UIContextMenuInteraction on iOS
iOS 13 added a new class named UIContextMenuInteraction what is used for attaching menus to views. When adding menu interaction to a view and user uses 3D Touch or long press gesture on devices not supporting it, a menu is presented alongside with the highlighted content view. Therefore depending on the available space, not all the menu items can fit into the menu.
Setting up UIContextMenuInteraction
UIContextMenuInteraction is initialised with a delegate. Delegate’s job is to create an instance of UIContextMenuConfiguration with provider block for creating a menu when needed. It also should be noted that delegate can return nil in what case no menu is shown.
Creating UIMenus and UIActions
Action provider of UIContextMenuConfiguration is a function taking in suggested menu items and returning an instance of UIMenu. Suggested menu items are the ones provided by responders from responder chain. For example we could use it for sharing actions among multiple responders.
Every menu item is represented by UIAction or another UIMenu allowing to have nested menus. UIActions have title and optionally image and state icon if the state is on. In addition we can explicitly disable actions and set a destructive appearance.
Creating menus using UIContextMenuInteraction are easy to setup and they look like familiar NSMenu when building iOS app for macOS.
UIContextMenu (Xcode 11 beta 4)