iOS 9 Quick Actions (3D Touch)

I am trying to understand doing Quick Actions (3D Touch) for iOS 9.

I wanted the user to select 1 of 4 filter to be applied to image, so if I select item 1, I will set the NSUserDefaults.standardUserDefaults() to the filter, then show the correct picture with the applied filter.

In AppDelete.swift:

func application(application: UIApplication, performActionForShortcutItem shortcutItem: UIApplicationShortcutItem, completionHandler: (Bool) -> Void) {
    var filterType:Int
    switch (shortcutItem.type) {
        ...set filterType
    }

    NSUserDefaults.standardUserDefaults().setInteger(filterType, forKey:"filterType")
    NSUserDefaults.standardUserDefaults().synchronize()        
}

In ViewController.swift:

override func viewDidLoad() {
    super.viewDidLoad()

    NSNotificationCenter.defaultCenter().addObserver(self, selector:"setDefaultFilter", name: UIApplicationWillEnterForegroundNotification, object:nil) // Handle enter from background
    setDefaultFilter()
}

func setDefaultFilter() {
    filterType = defaults.integerForKey("filterType")
    ...
    imageView.image = filterImage(defaultImage!, filter:filters[filterType])
}

However, when enter the app from the menu, it will always show the last selection (not the current selection). If I select item 1, nothing happened. I select item 3, item 1 will appeared.

I have also try passing parameters via appDelegate and the result is the same. I believe there are some issues with life cycle.

Any ideas?

NSUserDefaults write data on flash, which may not be so fast.

You can wait a little longer, like observe UIApplicationDidBecomeActiveNotification other than UIApplicationWillEnterForegroundNotification.

Or you can use other ways to pass params, e.g., as an instance variable in AppDelegate.