CODEWITHSUNDEEP
iosswift
Colin Hancey
Colin Hancey

Reputation: 229

Animate with draw-move for loop in Swift 4

I'm trying to create an on-screen animation for iOS with Swift 4 on the Xcode IDE by drawing an object to the screen, waiting, adjusting the object's location, and redrawing. However, when I do this inside of a for loop, the screen simply waits and then draws the object in the final position. Why is it doing this? How can I animate the way that I want to? Is there an alternative way to animate that I should be considering?

My code is here:

var counter = 0
for n in 0...10{
    counter = counter + 1
    draw_wheel(counter)
    sleep(1)
}

I simply see the object I am trying to draw in its final orientation after 10 seconds.

Upvotes: 2

Views: 277

Answers (1)

SIlvester
SIlvester

Reputation: 770

If you want to create step by step animation over the time, you should consider to use CADisplayLink instead of Timers or loops.

Basically CADisplayLink is a timer object that allows your application to synchronize its drawing to the refresh rate of the display and draw according to timestamp.

func createDisplayLink() {
    let displaylink = CADisplayLink(target: self,
                                    selector: #selector(step))

    displaylink.add(to: .current,
                    forMode: .default)
}

@objc func step(displaylink: CADisplayLink) {
    print(displaylink.timestamp)
}

Upvotes: 1

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