DefaultMailApp.swift

#!/usr/bin/swift

import Cocoa

struct DefaultApp {
    
    // Globals
    static let utiHandlerMicrosoft = [
        "com.apple.mail.email": "com.microsoft.outlook",
        "com.microsoft.outlook16.email-message": "com.microsoft.outlook",
        "public.vcard": "com.microsoft.outlook",
        "com.apple.ical.ics": "com.microsoft.outlook",
        "com.microsoft.outlook16.icalendar": "com.microsoft.outlook"
    ]
    
    static let utiHandlerApple = [
        "com.apple.mail.email": "com.apple.mail",
        "public.vcard": "com.apple.AddressBook",
        "com.apple.ical.ics": "com.apple.CalendarFileHandler",
    ]
    
    static let urlSchemeApple = ["mailto": "com.apple.mail"]
    static let urlSchemeMicrosoft = ["mailto": "com.microsoft.outlook"]
    
    // Funcs
    func getDefaultApp(handler: Dictionary<String, String>) {
        
        for (contentType, _) in handler {
            if let appHandler = LSCopyDefaultRoleHandlerForContentType(contentType as CFString, LSRolesMask.editor) {
                let bundleId = appHandler.takeRetainedValue()
                print("\(contentType): \(bundleId)")
            }
        }
    }
    
    func getDefaultScheme(handler: Dictionary<String, String>) {
        
        for (scheme, _) in handler {
            if let appScheme = LSCopyDefaultHandlerForURLScheme(scheme as CFString) {
                let bundleId = appScheme.takeRetainedValue()
                print("\(scheme): \(bundleId)")
            }
        }
    }
    
    func setDefaultApp(handler: Dictionary<String, String>) {
        for (contentType, lsHandler) in handler {
            LSSetDefaultRoleHandlerForContentType(contentType as CFString, LSRolesMask.editor, lsHandler as CFString)
        }
    }
    
    func setDefaultScheme(handler: Dictionary<String, String>) {
        for (scheme, lsHandler) in handler {
            LSSetDefaultHandlerForURLScheme(scheme as CFString, lsHandler as CFString)
        }
    }
}

/////////////////

class AppDelegate: NSObject, NSApplicationDelegate {
    
    let appName = "Demo App"
    let defaultApp = DefaultApp()
    
    // UI elements
    let window = NSWindow(contentRect: NSMakeRect(0, 0, 600, 400),
                          styleMask: .titled,
                          backing: .buffered,
                          defer: true)
    let label = NSTextField(frame: NSRect(x: 0, y: 300, width: 600, height: 60))
    let mailView = NSImageView(frame: NSRect(x: 120, y: 200, width: 80, height: 80))
    let outlookView = NSImageView(frame: NSRect(x: 120, y: 80, width: 80, height: 80))
    let mailButton = NSButton(frame: NSRect(x: 280, y: 210, width: 200, height: 60))
    let outlookButton = NSButton(frame: NSRect(x: 280, y: 90, width: 200, height: 60))
    let mailButtonClickedIcon = NSImageView(frame: NSRect(x: 500, y: 220, width: 40, height: 40))
    let outlookButtonClickedIcon = NSImageView(frame: NSRect(x: 500, y: 100, width: 40, height: 40))
    
    // Methods
    func setupUI() {
        
        // Menu
        setupMenu(appName: appName)
        
        // Window
        setupWindow()
        
        // "Normal" window presence (activation & exit)
        window.orderFrontRegardless()
        NSApp.activate(ignoringOtherApps: true)
        
        // Setup window's content view
        let contentView = window.contentView!
        
        // Dock icon
        setupDockIcon(path: "/System/Library/CoreServices/CoreTypes.bundle/Contents/Resources/ToolbarCustomizeIcon.icns")
        
        ///////////////
        
        // Label
        setupLabel(title: "Choose default email app")
        contentView.addSubview(label)
        
        // Icons
        setupIcon(appPath: "/Applications/Mail.app", imageView: mailView)
        contentView.addSubview(mailView)
        
        setupIcon(appPath: "/Applications/Microsoft Outlook.app", imageView: outlookView)
        contentView.addSubview(outlookView)
        
        // Buttons
        setupButton(title: "macOS Mail", button: mailButton)
        contentView.addSubview(mailButton)
        mailButton.action = #selector(mailButtonClicked)
        
        setupButton(title: "Outlook", button: outlookButton)
        contentView.addSubview(outlookButton)
        outlookButton.action = #selector(outlookButtonClicked)
        
        // Button clicked => OK icons
        setupHiddenIcon(path: "/System/Library/PrivateFrameworks/CommerceKit.framework/Versions/A/Resources/OSBadge.icns", imageView: mailButtonClickedIcon)
        contentView.addSubview(mailButtonClickedIcon)
        
        setupHiddenIcon(path: "/System/Library/PrivateFrameworks/CommerceKit.framework/Versions/A/Resources/OSBadge.icns", imageView: outlookButtonClickedIcon)
        contentView.addSubview(outlookButtonClickedIcon)

    }
    
    // Helper methods
    func setupMenu(appName: String) {
        
        let mainMenu = NSMenu()
        let subMenu = NSMenu()
        let menuItem = mainMenu.addItem(withTitle: "Application", action: nil, keyEquivalent: "")
        let titleQuit = NSLocalizedString("Quit", comment: "Quit menu item") + " " + appName
        let menuItemQuit = subMenu.addItem(withTitle: titleQuit, action: #selector(NSApplication.terminate(_:)), keyEquivalent: "q")
        menuItemQuit.target = NSApp
        mainMenu.setSubmenu(subMenu, for: menuItem)
        NSApp.mainMenu = mainMenu
    }
    
    func setupWindow() {
        
        window.center()
        window.styleMask.insert(.closable)
        window.styleMask.insert(.miniaturizable)
        window.backgroundColor = NSColor.controlBackgroundColor
        window.title = appName
    }
    
    func setupDockIcon(path: String) {
        
        let icon = NSImage(byReferencingFile: path)!
        icon.size = CGSize(width: 128, height: 128)
        NSApp.applicationIconImage = icon
    }
    
    func setupLabel(title: String) {
        
        label.isBezeled = false
        label.isEditable = false
        label.font = NSFont.systemFont(ofSize: 40)
        label.alignment = .center
        label.stringValue = title
    }
    
    func setupIcon(appPath: String, imageView: NSImageView) {
        
        let appIcon: NSImage = NSWorkspace.shared.icon(forFile: appPath)
        appIcon.size = NSSize(width: 80.0, height: 80.0)
        imageView.image = appIcon
    }
    
    func setupButton(title: String, button: NSButton) {
        
        button.bezelStyle = .regularSquare
        button.font = NSFont.systemFont(ofSize: 20)
        button.title = title
    }
    
    func setupHiddenIcon(path: String, imageView: NSImageView) {
        
        let icon: NSImage = NSImage(byReferencingFile: path)!
        icon.size = NSSize(width: 30.0, height: 30.0)
        imageView.image = icon
        imageView.isHidden = true
    }
    
    // Button actions
    @objc func mailButtonClicked(sender: AnyObject) {
        
        print("macOS Mail selected")
        print("Current settings:")
        defaultApp.getDefaultApp(handler: DefaultApp.utiHandlerMicrosoft)
        defaultApp.getDefaultScheme(handler: DefaultApp.urlSchemeMicrosoft)
        defaultApp.setDefaultApp(handler: DefaultApp.utiHandlerApple)
        defaultApp.setDefaultScheme(handler: DefaultApp.urlSchemeApple)
        
        // Handle icon visibility
        mailButtonClickedIcon.isHidden = false
        outlookButtonClickedIcon.isHidden = true
    }
    
    @objc func outlookButtonClicked(sender: AnyObject) {
        
        print("Outlook selected")
        print("Current settings:")
        defaultApp.getDefaultApp(handler: DefaultApp.utiHandlerMicrosoft)
        defaultApp.getDefaultScheme(handler: DefaultApp.urlSchemeMicrosoft)
        defaultApp.setDefaultApp(handler: DefaultApp.utiHandlerMicrosoft)
        defaultApp.setDefaultScheme(handler: DefaultApp.urlSchemeMicrosoft)
        
        // Handle icon visibility
        outlookButtonClickedIcon.isHidden = false
        mailButtonClickedIcon.isHidden = true
    }
    
    // Required app delegate method
    func applicationDidFinishLaunching(_ aNotification: Notification) {
        
        setupUI()
    }
    
    // Close app when toolbar red button is pushed
    func applicationShouldTerminateAfterLastWindowClosed(_ app: NSApplication) -> Bool {
        return true
    }
}

// Setup app delegate and run the app
let thisApp = NSApplication.shared
NSApp.setActivationPolicy(.regular)
let appDelegate = AppDelegate()
thisApp.delegate = appDelegate
thisApp.run()