Implement macOS share button

Multiplatform/macOS/Article/SharingServiceView.swift

@@ -0,0 +1,56 @@
+//
+//  SharingServiceView.swift
+//  Multiplatform macOS
+//
+//  Created by Maurice Parker on 7/14/20.
+//  Copyright © 2020 Ranchero Software. All rights reserved.
+//
+
+import SwiftUI
+import AppKit
+import Articles
+
+class SharingServiceController: NSViewController {
+	
+	var sharingServicePickerDelegate: SharingServicePickerDelegate? = nil
+	var articles = [Article]()
+	var completion: (() -> Void)? = nil
+
+	override func loadView() {
+		view = NSView()
+	}
+	
+	override func viewDidAppear() {
+		guard let anchor = view.superview?.superview else { return }
+		
+		sharingServicePickerDelegate = SharingServicePickerDelegate(self.view.window, completion: completion)
+		
+		let sortedArticles = articles.sortedByDate(.orderedAscending)
+		let items = sortedArticles.map { ArticlePasteboardWriter(article: $0) }
+		
+		let sharingServicePicker = NSSharingServicePicker(items: items)
+		sharingServicePicker.delegate = sharingServicePickerDelegate
+		
+		sharingServicePicker.show(relativeTo: anchor.bounds, of: anchor, preferredEdge: .minY)
+	}
+	
+}
+
+struct SharingServiceView: NSViewControllerRepresentable {
+
+	var articles: [Article]
+	@Binding var showing: Bool
+	
+	func makeNSViewController(context: Context) -> SharingServiceController {
+		let controller = SharingServiceController()
+		controller.articles = articles
+		controller.completion = {
+			showing = false
+		}
+		return controller
+	}
+
+	func updateNSViewController(_ nsViewController: SharingServiceController, context: Context) {
+	}
+	
+}