Which method is called when my custom keyboard is shown on screen?

Question

I have developed custom keyboard. Now I want to give functionality like if some user choose color from my container app and then open my keyboard the background color of my keyboard changes to that color. How to achieve this? Which method gets called every time when some one switch to my custom keyboard so that i can write code on that method?

Answer 1

there is not a predefined method called, but you can set a NSNotification. In your viewdidload method insert:

NSNotificationCenter.defaultCenter().addObserver(self, selector: "keyboardWasShown:", name: UIKeyboardDidShowNotification, object: nil)
NSNotificationCenter.defaultCenter().addObserver(self, selector: "keyboardWillBeHidden:", name: UIKeyboardWillHideNotification, object: nil)

and then add the two methods that will be called the the keyboard appears or disappears:

func keyboardWasShown(notification: NSNotification) {
    print("keyboard up")
}

func keyboardWillBeHidden(notification: NSNotification) {
    print("keyboard down")
}

But remember to remove the notifications in viewWillDisappear:

NSNotificationCenter.defaultCenter().removeObserver(self, name: UIKeyboardDidShowNotification, object: self.view.window)
NSNotificationCenter.defaultCenter().removeObserver(self, name: UIKeyboardWillHideNotification, object: self.view.window)

bye.

Answer 2

Save the color property as hex string in UserDefaults with suite name. Then use this color in extension app's viewDidLoad method as background color.