get-started-with-writing-tools.md

Get started with writing tools

Presenter: Dongyuan Liu, Text Input & Internationalization

Link: https://developer.apple.com/wwdc24/10168

New suite of features available in text views across all kinds of apps

• Helps users polish text they're working on

Introducing writing tools

• Help users proofread, rewrite, or transform text
• Suggestions appear inline
• When you hover over selected text, it shows up with an option to open the Writing Tools panel
• Can review and apply or reject suggestions one-by-one
• Can also work with non-editable text - user can copy results

Native text views

• If you're using a supported text view, it just shows up and works

New delegate methods for Writing Tools:

func textViewWritingToolsWillBegin(_ textView: UITextView) {
    // Take necessary steps to prepare. For example, disable iCloud sync.
}

func textViewWritingToolsDidEnd(_ textView: UITextView) {
    // Take necessary steps to recover. For example, reenable iCloud sync.
}

if !textView.isWritingToolsActive {
    // Do work that needs to be avoided when Writing Tools is interacting with text view
    // For example, in the textViewDidChange callback, app may want to avoid certain things
       when Writing Tools is active
}

Text Storage

• Chunking with animations
• "Original" button to toggle between original and rewritten text
• Proofreading where user can choose whether or not to apply
• Do not persist data while writing tools are active

Controlling behavior

By default, the system offers writing tools by default. You can opt out of the full experience:

textView.writingToolsBehavior = .limited

textView.writingToolsBehavior = .none

You can specify accepted text formats:

textView.writingToolsAllowedInputOptions = [.plainText]

textView.writingToolsAllowedInputOptions = [.plainText, .richText, .table]

Similar APIs for WKWebView:

// For `WKWebView`, the `default` behavior is equivalent to `.limited`

extension WKWebViewConfiguration {
    @available(iOS 18.0, *)
    open var writingToolsBehavior: UIWritingToolsBehavior { get set }
}

extension WKWebViewConfiguration {
    @available(macOS 15.0, *)
    open var writingToolsBehavior: NSWritingToolsBehavior { get set }
}

extension WKWebView {
    /// @discussion If the Writing Tools behavior on the configuration is `.limited`, this will always be `false`.
    @available(iOS 18.0, macOS 15.0, *)
    open var isWritingToolsActive: Bool { get }
}

Protecting ranges

• Specify ranges to ignore, such as quotes or code blocks

// Returned `NSRange`s are relative to the substring of the textView’s textStorage from `enclosingRange`
func textView(_ textView: UITextView, writingToolsIgnoredRangesIn
        enclosingRange: NSRange) -> [NSRange] {
    let text = textView.textStorage.attributedSubstring(from: enclosingRange)
    return rangesInappropriateForWritingTools(in: text)
}

Custom text views

On iOS and iPadOS, as long as your app adopts UITextInteraction, you get writing tools in the callout bar or context menu for free If you can't use this, you can alternately adopt UITextSelectionDisplayInteraction or UIEditMenuInteraction For text views that don't use text interactions, new property isEditable in UITextInput protocol to indicate if your view supports editing

protocol UITextInput {
    @available(iOS 18.0, macOS 15.0, *)
    optional var isEditable: Bool { get }
}

On Mac, we show writing tools automatically in context menu and Edit menu for custom text views

• Make sure your text view adopts NSServicesMenuRequestor

class CustomTextView: NSView, NSServicesMenuRequestor {
    required init?(coder: NSCoder) {
        super.init(coder: coder)
        
        self.menu = NSMenu()
        self.menu?.addItem(NSMenuItem(title: "Custom Text View", action: nil,
            keyEquivalent: ""))
        self.menu?.addItem(NSMenuItem(title: "Copy", action: #selector(copy(_:)), 
            keyEquivalent: ""))
    }
  
    override func draw(_ dirtyRect: NSRect) {
        super.draw(dirtyRect)
        
        // Custom text drawing code...
    }
}

You can override validRequestor(forSendType: returnType:) to add writing tools for free:

class CustomTextView: NSView, NSServicesMenuRequestor {
    override func validRequestor(forSendType sendType: NSPasteboard.PasteboardType?, 
                                 returnType: NSPasteboard.PasteboardType?) -> Any? {
        if sendType == .string || sendType == .rtf {
            return self
        }
        return super.validRequestor(forSendType: sendType, returnType: returnType)
    }
    
    nonisolated func writeSelection(to pboard: NSPasteboard,
                                    types: [NSPasteboard.PasteboardType]) -> Bool {
        // Write plain text and/or rich text to pasteboard
        return true
    }

    // Implement readSelection(from pboard: NSPasteboard)
       as well for editable view
}