How to add more styling options to the UIMenuController of UITextView?

Question

When UITextView's allowsEditingTextAttributes property is enabled,

textView.allowsEditingTextAttributes = true

the textview can show the BIU (bold/italic/underlined) styling options in the context menu by UIMenuController.

UIMenuController - BIU Styling Options #1

UIMenuController - BIU Styling Options #2

I wonder how to add more styling options (e.g., strikethrough, highlight) to the context menu inside the BIU. For example, the iOS' native Notes app has four options (BIU + strikethrough) inside the styling menu.

BIU Styling Options in the native Notes app

Is there any way to do it? I have been spending hours to find a way to override the "Selector(("_showTextStyleOptions:"))" but couldn't find out how.. Please help me!!

score 5 · Answer 1 · answered Jul 12 '18 at 16:19

When the editing menu is about to become visible, you get a canPerformAction(_:withSender:) call in your UITextView. This method is called again when the user selects a button within the menu. You can check if the font style button was selected and add a custom button to that submenu.

class MyTextView: UITextView {

    override func canPerformAction(_ action: Selector, withSender sender: Any?) -> Bool {
        let menuController = UIMenuController.shared
        if var menuItems = menuController.menuItems,
            (menuItems.map { $0.action }).elementsEqual([.toggleBoldface, .toggleItalics, .toggleUnderline]) {
            // The font style menu is about to become visible
            // Add a new menu item for strikethrough style
            menuItems.append(UIMenuItem(title: "Strikethrough", action: .toggleStrikethrough))
            menuController.menuItems = menuItems
        }
        return super.canPerformAction(action, withSender: sender)
    }

    @objc func toggleStrikethrough(_ sender: Any?) {
        print("Strikethrough button was pressed")
    }

}

fileprivate extension Selector {
    static let toggleBoldface = #selector(MyTextView.toggleBoldface(_:))
    static let toggleItalics = #selector(MyTextView.toggleItalics(_:))
    static let toggleUnderline = #selector(MyTextView.toggleUnderline(_:))
    static let toggleStrikethrough = #selector(MyTextView.toggleStrikethrough(_:))
}

According to documentation, you may have to call update() on the UIMenuController after adding the button. But this was not necessary in my case.

How to add more styling options to the UIMenuController of UITextView?

1 Answers1