Adding an animation fade effect when the UIScreen Brightness is changed (Swift)

Question

Just wondering if it is at all possible for the screen brightness to be changed with a fade effect. The screen brightness can yes be changed using UIScreen.mainScreen().brightness = CGFloat(1) but that just immediately changes the current brightness to the variable.

I want to know if you can animate the change of brightness. For example, the current brightness is 0.2 and I want to change it to 0.8 with a fade effect with an increment of 0.1 until it reaches 0.8

Can this be done in swift 2.3?

Answer 1

There are ready made animation methods for UIView and CALayers. But in your case, you want to animate a UIScreen property so you have to do this manually with a timer to gradually change the brightness from 0.1 to 0.8 over a time interval.

    var timer = Timer.scheduledTimer(timeInterval: 0.4, target: self, selector: #selector(self.update), userInfo: nil, repeats: true)

    func update() {
        if (UI.mainScreen().brightness >= 0.8) {
           Timer.invalidate(timer)
        }
        else {
        UIScreen.mainScreen().brightness += 0.1
        }
    }

This will change the brightness by 0.1 every 0.4 seconds. When it reaches a value of 0.8 or more it stops. You can make a more gradual or immediate effect by playing with the timerInterval parameter.