silica-viewer/SilicaViewer/ExportAccessoryView.swift

import Foundation
import AppKit
import UniformTypeIdentifiers

class ExportAccessoryView : NSView {
    
    @IBOutlet weak var typeBox: NSPopUpButton!
    
    var savePanel: NSSavePanel? = nil
    
    func setSavePanel(_ savePanel: NSSavePanel?) {
        self.savePanel = savePanel
    }
    
    func setPossibleOptions(_ options : Array<String>) {
        for option in options {
            typeBox.addItem(withTitle: option.uppercased())
        }
    }
    
    @IBAction func changeFileFormat(_ sender: Any) {
        if #available(macOS 11.0, *) {
            savePanel?.allowedContentTypes = [UTType(filenameExtension: (typeBox.titleOfSelectedItem?.lowercased())!)!]
        } else {
            savePanel?.allowedFileTypes?.removeAll()
            savePanel?.allowedFileTypes?.append((typeBox.titleOfSelectedItem?.lowercased())!)
        };
    }
}