ToolbarItemWithControlValidating

ToolbarItemWithControlValidating.swift

// View-based toolbar items do not auto-validate by default, since the toolbar item view may
// be of any type. This subclass validates a toolbar item NSControl view against its action target.
class ToolbarItemWithControlValidating: NSToolbarItem {
    override func validate() {
        // validate with views view
        if let action = self.action {
            let validator = NSApp.target(forAction: action, to: self.target, from: self) as AnyObject?
            switch validator {
            case let validator as NSToolbarItemValidation:
                isEnabled = validator.validateToolbarItem(self)
            case let validator as NSUserInterfaceValidations:
                isEnabled = validator.validateUserInterfaceItem(self)
            default:
                isEnabled = false
            }
        } else {
            super.validate()
        }
    }
}