Fix calling UI from a background thread

CHANGELOG.md

@@ -16,6 +16,7 @@ unreleased
 - Fix an issue where `⌘←` was ignored when the cursor locates at the end of the document.
 - Fix an issue where save dialog layout crrupted when toggle visibility of the file browser.
 - Fix an issue where no alart was raised on saving even when document contains lossy yen signs.
+- Fix a possible crash on print.
 
 
 

CotEditor/Sources/Document.swift

@@ -641,7 +641,7 @@ final class Document: NSDocument, AdditionalDocumentPreparing, EncodingHolder {
         printOperation.canSpawnSeparateThread = true  // display print progress panel as a sheet
         
         // setup print panel
-        self.printPanelAccessoryController.view.setContentHuggingPriority(.fittingSizeCompression, for: .horizontal)
+        printOperation.printPanel.addAccessoryController(self.printPanelAccessoryController)
         printOperation.printPanel.options.formUnion([.showsPaperSize, .showsOrientation, .showsScaling])
         
         return printOperation

CotEditor/Sources/PrintTextView.swift

@@ -385,7 +385,9 @@ final class PrintTextView: NSTextView, NSLayoutManagerDelegate, Themable {
             }
             if let controller = NSPrintOperation.current?.printPanel.accessoryControllers.first as? PrintPanelAccessoryController {
                 self.syntaxStyle?.highlightAll { [weak controller] in
-                    if let controller = controller, !controller.view.isHidden {
+                    DispatchQueue.main.async {
+                        guard let controller = controller, !controller.view.isHidden else { return }
+                        
                         controller.needsUpdatePreview = true
                     }
                 }