Written by Amy
on September 16, 2017

스탠포드 iOS 강의노트 L5

Lecture 5

Lecture 5: Gestures

Course Description Updated for iOS 10 and Swift. Tools and APIs required to build applications for the iPhone and iPad platforms using the iOS SDK. User interface design for mobile devices and unique user interactions using multi-touch technologies. Object-oriented design using model-view-controller paradigm, memory management, Swift programming language. Other topics include: object-oriented database API, animation, mobile device power management, multi-threading, networking and performance considerations.

This course material is only available in the iTunes U app on iPhone or iPad.
Developing iOS 10 Apps with Swift by Stanford

Gestures

Gestures are recognized by instances of UIGestureRecognizer
Adding a gesture recognizer to a UIView

UIPinchGestureRecognizer

var scale: CGFloat // not read-only (can reset)
var velocity: CGFloat { get } // scale factor per second

// Pinch - UIPinchGestureRecognizer
@objc func changeScale(byReactingTo pinchRecognizer: UIPinchGestureRecognizer)
{
    switch pinchRecognizer.state {
    case .changed, .ended:
        scale *= pinchRecognizer.scale
        pinchRecognizer.scale = 1
    default:
        break
    }
}

UIRotationGestureRecognizer

var rotation: CGFloat // not read-only (can reset); in radians
var velocity: CGFloat { get } // radians per second

UISwipeGestureRecognizer

var direction: UISwipeGestureRecoginzerDirection // which swipe directions you want
var numberOfTouchesRequired: Int // finger count

UITapGestureRecognizer

var numberOfTapsRequired: Int // single tap, double tap, etc. var
numberOfTouchesRequired: Int // finger count

@objc func toggleEyes(byReactingTo tapRecognizer: UITapGestureRecognizer)
{
    if tapRecognizer.state == .ended {
        let eyes: FacialExpression.Eyes = (expression.eyes == .closed) ? .open : .closed
        expression = FacialExpression(eyes: eyes, mouth: expression.mouth)
    }
}

Sample Code

@IBOutlet weak var skullView: SkullView! {
    didSet {
        let handler = #selector(skullView.changeScale(byReactingTo:))
        
        let pinchRecognizer = UIPinchGestureRecognizer(target: skullView, action: handler)
        skullView.addGestureRecognizer(pinchRecognizer)
        
        let tapRecognizer = UITapGestureRecognizer(target: self, action: #selector(self.toggleEyes(byReactingTo:)))
        skullView.addGestureRecognizer(tapRecognizer)
        
        let swipeUpRecognizer = UISwipeGestureRecognizer(target:self, action: #selector(increaseHappiness))
        swipeUpRecognizer.direction = .up
        skullView.addGestureRecognizer(swipeUpRecognizer)
        
        let swipeDownRecognizer = UISwipeGestureRecognizer(target:self, action: #selector(decreaseHappiness))
        swipeDownRecognizer.direction = .down
        skullView.addGestureRecognizer(swipeDownRecognizer)
        
        updateUI()
    }
}

← → Top