Adds QuickLook preview for monster files. It shows how the monster will appear after being imported.

MonsterPreview/PreviewViewController.swift

@@ -0,0 +1,43 @@
+//
+//  PreviewViewController.swift
+//  MonsterPreview
+//
+//  Created by Tom Hicks on 4/7/21.
+//
+
+import UIKit
+import QuickLook
+import SwiftUI
+
+class PreviewViewController: UIViewController, QLPreviewingController {
+        
+    func preparePreviewOfFile(at url: URL, completionHandler handler: @escaping (Error?) -> Void) {
+        
+        let document = MonsterDocument(fileURL: url)
+        document.open(completionHandler: {[weak self](_) in
+                        self?.presentMonsterViewController(for: document)
+                        handler(nil)
+        })
+    }
+    
+    func presentMonsterViewController(for document: MonsterDocument) {
+        let monsterViewModel = MonsterImportHelper.import5ESBMonster(document.monsterDTO ?? MonsterDTO())
+        let monsterViewController = UIHostingController(rootView: MonsterDetailView(viewModel: monsterViewModel))
+        monsterViewController.loadViewIfNeeded()
+        monsterViewController.view.layoutIfNeeded()
+        addChild(monsterViewController)
+        view.addSubview(monsterViewController.view)
+        monsterViewController.didMove(toParent: self)
+        
+        if let monsterView = monsterViewController.view {
+            monsterView.translatesAutoresizingMaskIntoConstraints = false
+            NSLayoutConstraint.activate([
+                monsterView.leftAnchor.constraint(equalTo: view.leftAnchor),
+                monsterView.rightAnchor.constraint(equalTo: view.rightAnchor),
+                monsterView.topAnchor.constraint(equalTo: view.topAnchor),
+                monsterView.bottomAnchor.constraint(equalTo: view.bottomAnchor),
+            ])
+        }
+    }
+
+}