silica-viewer/SilicaViewer/ExportAccessoryView.swift

import Foundation
import AppKit

class ExportAccessoryView : NSView {
    
    @IBOutlet weak var typeBox: NSPopUpButton!
    
    var savePanel: NSSavePanel? = nil
    
    func setSavePanel(_ savePanel: NSSavePanel?) {
        self.savePanel = savePanel
    }
    
    @IBAction func changeFileFormat(_ sender: Any) {
        switch(typeBox.indexOfSelectedItem) {
        case 0:
            savePanel?.allowedFileTypes = ["tiff"]
            break
        case 1:
            savePanel?.allowedFileTypes = ["bmp"]
            break
        case 2:
            savePanel?.allowedFileTypes = ["jpeg"]
            break
        case 3:
            savePanel?.allowedFileTypes = ["png"]
            break
        case 4:
            savePanel?.allowedFileTypes = ["psd"]
            break
        default:
            break
        }
    }
}

extension NSView {
    class func fromNib<T: NSView>() -> T? {
        var topLevelObjects : NSArray?
        guard Bundle.main.loadNibNamed("\(self)", owner: nil, topLevelObjects: &topLevelObjects) else {
            return nil
        }
        return topLevelObjects!.first(where: { $0 is T }) as? T
    }
}