From c0f47191be0265d55ceca02233caf85946831e65 Mon Sep 17 00:00:00 2001
From: redstrate <josh@redstrate.com>
Date: Mon, 14 Jun 2021 12:17:58 -0400
Subject: [PATCH] Always call handler in thumbnail and quicklook generation
 (#4)

---
 Quicklook/PreviewViewController.swift | 10 +++++++---
 Thumbnail/ThumbnailProvider.swift     | 10 ++++++----
 2 files changed, 13 insertions(+), 7 deletions(-)

diff --git a/Quicklook/PreviewViewController.swift b/Quicklook/PreviewViewController.swift
index 4a2595e..401f593 100644
--- a/Quicklook/PreviewViewController.swift
+++ b/Quicklook/PreviewViewController.swift
@@ -15,16 +15,18 @@ class PreviewViewController: NSViewController, QLPreviewingController {
         fc.coordinate(with: [intent], queue: .main) { (err) in
             if err == nil {
                 do {
+                    let standardError = NSError(domain: "procreate-viewer", code: 1, userInfo: nil)
+
                     guard let archive = Archive(data: try Data(contentsOf: intent.url), accessMode: Archive.AccessMode.read) else {
-                        return
+                        throw standardError
                     }
                     
                     guard let entry = archive[ThumbnailPath] else {
-                        return
+                        throw standardError
                     }
                     
                     guard let thumbnailData = readData(archive: archive, entry: entry) else {
-                        return
+                        throw standardError
                     }
 
                     self.imageView?.image = NSImage(data: thumbnailData)
@@ -32,9 +34,11 @@ class PreviewViewController: NSViewController, QLPreviewingController {
                     handler(nil)
                 } catch {
                     NSLog("Could not load file \(intent.url.lastPathComponent) to preview it")
+                    handler(err)
                 }
             } else {
                 NSLog("Could not find file \(intent.url.lastPathComponent) to preview it")
+                handler(err)
             }
         }
     }
diff --git a/Thumbnail/ThumbnailProvider.swift b/Thumbnail/ThumbnailProvider.swift
index 1a34b1f..4db930f 100644
--- a/Thumbnail/ThumbnailProvider.swift
+++ b/Thumbnail/ThumbnailProvider.swift
@@ -4,17 +4,19 @@ import Cocoa
 
 class ThumbnailProvider: QLThumbnailProvider {
     override func provideThumbnail(for request: QLFileThumbnailRequest, _ handler: @escaping (QLThumbnailReply?, Error?) -> Void) {
+        let standardError = NSError(domain: "procreate-viewer", code: 1, userInfo: nil)
+
         do {
             guard let archive = Archive(data: try Data(contentsOf: request.fileURL), accessMode: Archive.AccessMode.read) else {
-                return
+                throw standardError
             }
             
             guard let entry = archive[ThumbnailPath] else {
-                return
+                throw standardError
             }
             
             guard let thumbnailData = readData(archive: archive, entry: entry) else {
-                return
+                throw standardError
             }
             
             let image = NSImage(data: thumbnailData)
@@ -51,7 +53,7 @@ class ThumbnailProvider: QLThumbnailProvider {
             handler(reply, nil)
         } catch {
             NSLog("Could not access file \(request.fileURL.lastPathComponent) to preview it")
-            handler(nil, nil)
+            handler(nil, standardError)
         }
     }
 }