On AppKit, menu items and toolbar items have validateMenuItem(_:) and validateToolbarItem(_:) respectively. However, by new touch bar items, there is no such convenience method to validate appropriate items at the right moment.
I'm now validating touch bar items every time when I change the related values and invoke a validation method in didSet (see the following sample code). But I feel it is not a good way because the related values must know there is a touch bar item depending on it.
var foo: Foo? {
didSet {
if #available(macOS 10.12.1, *), NSClassFromString("NSTouchBar") != nil {
self.validateTouchBarItem(identifier: .foo)
}
}
}
@available(macOS 10.12.1, *)
func validateTouchBarItem(identifier: NSTouchBarItemIdentifier) {
guard
let item = self.touchBar?.item(forIdentifier: identifier),
let button = item.view as? NSButton
else { return }
switch identifier {
case NSTouchBarItemIdentifier.foo:
button.isEnabled = (self.foo != nil)
default: break
}
}
Another way I'm using is the Cocoa-binding and KVO, however, it doesn't always work well.
So, I'm curious whether there is any recommended or a defacto-standard way to validate touch bar items, especially containing NSButton and NSSegmentedControl. I wanna change not only the availability of items but sometimes also images or colors of them depending on the situation. How do you guys validate touch bar items?
I improved my touch bar validation system by myself and made the following protocol and extensions.
@available(macOS 10.12.1, *)
protocol TouchBarItemValidations: class {
func validateTouchBarItem(_ item: NSTouchBarItem) -> Bool
}
@available(macOS 10.12.1, *)
extension NSTouchBarProvider {
func validateTouchBarItems() {
guard NSClassFromString("NSTouchBar") != nil else { return } // run-time check
guard let touchBar = self.touchBar else { return }
// validate currently visible touch bar items
for identifier in touchBar.itemIdentifiers {
guard let item = touchBar.item(forIdentifier: identifier) as? NSCustomTouchBarItem else { continue }
item.validate()
}
}
}
@available(macOS 10.12.1, *)
extension NSCustomTouchBarItem: NSValidatedUserInterfaceItem {
func validate() {
// validate content control
if let control = self.control,
let action = control.action,
let validator = NSApp.target(forAction: action, to: control.target, from: self)
{
if let validator = validator as? TouchBarItemValidations {
control.isEnabled = validator.validateTouchBarItem(self)
} else if let validator = validator as? NSUserInterfaceValidations {
control.isEnabled = (validator as AnyObject).validateUserInterfaceItem(self)
}
}
}
// MARK: Validated User Interface Item Protocol
public var action: Selector? {
return self.control?.action
}
public var tag: Int {
return self.control?.tag ?? 0
}
// MARK: Private Methods
private var control: NSControl? {
return self.view as? NSControl
}
}
@available(macOS 10.12.1, *)
extension AppDelegate {
func applicationDidUpdate(_ notification: Notification) {
// validate touch bar items
if #available(macOS 10.12.1, *) {
if let window = NSApp.mainWindow {
for responder in sequence(first: window.firstResponder, next: { $0.nextResponder }) {
responder.validateTouchBarItems()
}
}
}
}
}
You should modify AppDelegate's applicationDidUpdate(:_) if you already have one, but except for that, nothing complex to add. You can now use validateTouchBarItem(_:) or normal validateUserInterfaceItem(_:) to validate your own touch bar items!
I suppose this works well at least for my requirements.