Disable all menu item images in a Mac app.

NSMenuItem+RSCore.swift

//
//  NSMenuItem+RSCore.swift
//  RSCore
//
//  Created by Brent Simmons on 1/5/26.
//

#if os(macOS)
import AppKit
import ObjectiveC

extension NSMenuItem {
	/// Disables all icons in all regular menu items.
	///
	/// Call `NSMenuItem.disableIcons` early (from AppDelegate.init is good).
	public static func disableIcons() {
		let originalSelector = #selector(getter: image)
		let nilImageSelector = #selector(returnNilInsteadOfImage)

		guard
			let originalMethod = class_getInstanceMethod(NSMenuItem.self, originalSelector),
			let newMethod = class_getInstanceMethod(NSMenuItem.self, nilImageSelector)
		else {
			return
		}

		method_exchangeImplementations(originalMethod, newMethod)
	}

	@objc private func returnNilInsteadOfImage() -> NSImage? {
		// In a palette menu, as appears for example in the "zoom" button of a window,
		// we want the icons to appear because labels are hidden.
		if let menu, case .palette = menu.presentationStyle {
			// Because the method implementations are swapped, this will return the original image.
			return self.returnNilInsteadOfImage()
		} else {
			return nil
		}
	}
}
#endif