Building a Genmoji-Ready Input System on macOS with SwiftUI

Introduction

With the evolution of Apple’s text system, user input is no longer just plain strings. Features like Genmoji introduce a new category of content:

Adaptive, image-based glyphs embedded inside text.

On macOS, supporting this kind of expressive input requires:

• Bridging AppKit into SwiftUI
• Handling rich text (NSAttributedString)
• Preserving content through serialization

In this article, we’ll build a minimal macOS app that:

• Accepts rich text input
• Supports image-based glyph content
• Persists and restores content safely

Key Concept: Rich Text, Not String

If you treat input like this:

let text: String = "Hello 😊"

It works for Unicode emoji.

But Genmoji-like content is different:

• Stored as image glyphs
• Embedded in NSAttributedString
• Not representable as plain String

So the rule is:

Always treat expressive input as rich text.

Architecture Overview

We’ll build a lightweight app with this structure:

GenmojiNotesMac
├── ContentView
├── GenmojiMacTextEditor (NSTextView bridge)
├── GenmojiMacTextPreview
├── GenmojiMacViewModel
└── RichTextStore (serialization layer)

Step 1: Bridging NSTextView into SwiftUI

SwiftUI doesn’t provide a native rich text editor that supports advanced input.

We use NSViewRepresentable:

struct GenmojiMacTextEditor: NSViewRepresentable {
    @Binding var attributedText: NSAttributedString

    func makeCoordinator() -> Coordinator {
        Coordinator(attributedText: $attributedText)
    }

    func makeNSView(context: Context) -> NSScrollView {
        let scrollView = NSScrollView()
        let textView = NSTextView()

        textView.isEditable = true
        textView.isSelectable = true

        // Critical for expressive / image-based content
        textView.importsGraphics = true

        textView.delegate = context.coordinator
        context.coordinator.textView = textView

        scrollView.documentView = textView
        return scrollView
    }

    func updateNSView(_ nsView: NSScrollView, context: Context) {
        guard let textView = nsView.documentView as? NSTextView else { return }
        textView.textStorage?.setAttributedString(attributedText)
    }
}

Why importsGraphics matters

On macOS, enabling:

textView.importsGraphics = true

allows the text view to:

• Accept pasted images
• Handle rich graphical content
• Support expressive glyph-like input

Step 2: Persisting Rich Text with RTFD

To preserve rich content, we use RTFD.

func serialize(text: NSAttributedString) throws -> Data {
    try text.data(
        from: NSRange(location: 0, length: text.length),
        documentAttributes: [.documentType: .rtfd]
    )
}

Why RTFD?

Because it:

• Stores embedded images
• Preserves attributes
• Is native to AppKit/UIKit

Step 3: Restoring Content

func deserialize(data: Data) throws -> NSAttributedString {
    try NSAttributedString(
        data: data,
        options: [.documentType: .rtfd],
        documentAttributes: nil
    )
}

Now your content survives:

• App reloads
• Copy/paste
• Disk persistence

Step 4: ViewModel Layer

Keep business logic separate from UI:

@MainActor
final class GenmojiMacViewModel: ObservableObject {
    @Published var inputText = NSAttributedString(string: "")
    @Published var previewText = NSAttributedString(string: "")

    private var savedData: Data?

    func save() {
        savedData = try? serialize(text: inputText)
    }

    func restore() {
        if let data = savedData {
            inputText = try? deserialize(data: data) ?? NSAttributedString()
        }
    }
}

Step 5: Preview UI

Display the rendered content:

struct GenmojiMacTextPreview: NSViewRepresentable {
    let attributedText: NSAttributedString

    func makeNSView(context: Context) -> NSScrollView {
        let scrollView = NSScrollView()
        let textView = NSTextView()

        textView.isEditable = false
        textView.importsGraphics = true
        textView.textStorage?.setAttributedString(attributedText)

        scrollView.documentView = textView
        return scrollView
    }

    func updateNSView(_ nsView: NSScrollView, context: Context) {}
}

Final Thoughts

Modern Apple platforms are moving toward:

Expression as a first-class input primitive

That means:

• Text is no longer just text
• UI must handle rich, adaptive content
• Persistence must preserve fidelity

If you’re building input-heavy apps, this is the direction to follow.