手势简单应用

• 两指缩放
• 上下滑动可以改变笑脸弧度

@IBDesignable 使View可以在storyBoard中实时预览

@IBInspectable 使属性可以在storyBoard中设置

HappinessViewController.swift

import UIKit

public class HappinessViewController: UIViewController ,FaceViewDataSource{

    var happiness:Int = 25 {  //0 = vary sad,100 = ecstatic
            didSet{
                happiness = min(max(happiness,0),100)
                println("happiness = \(happiness)")
                updateUI()
            }
    }

    private struct Constants{
        static let HappinessGestureScale:CGFloat = 4
    }

    // 滑动的事件
    @IBAction func changeHappiness(gesture: UIPanGestureRecognizer) {
        switch gesture.state{
        case .Ended:fallthrough
        case .Changed:
            let translation =
                gesture.translationInView(faceView)
            let happinessChange = -Int(translation.y / Constants.HappinessGestureScale)

            if happiness != 0 {
                happiness += happinessChange
                gesture.setTranslation(CGPointZero, inView: faceView)
            }

        default :break
        }
    }

    @IBOutlet weak var faceView: FaceUIView!{
        didSet{
            faceView.dataSource  = self
            // 添加缩放事件，调用的是daceView里面的scale方法
            faceView.addGestureRecognizer(UIPinchGestureRecognizer(target: faceView, action: "scale:"))
//            faceView.addGestureRecognizer(UIPanGestureRecognizer(target: faceView, action: "scale:"))
        }
    }

    private func updateUI(){
        faceView.setNeedsDisplay()
    }

    func smilinessForFaceView(sender:FaceUIView) -> Double?{
        return Double(happiness-50)/50
    }
}

FaceUIView.swift

import UIKit

protocol FaceViewDataSource :class{
    func smilinessForFaceView(sender: FaceUIView) -> Double?
}

@IBDesignable
class FaceUIView: UIView {

    // @IBInspectable 使属性可以在storyBoard中设置
    @IBInspectable
     var lineWidth:CGFloat = 3{didSet{setNeedsDisplay()}}
    @IBInspectable var color:UIColor = UIColor.blueColor() { didSet{setNeedsDisplay() } }
    @IBInspectable var scale:CGFloat = 0.90{didSet { setNeedsDisplay() } }

    var faceCenter:CGPoint{return convertPoint(center,fromView:superview)}
    // 笑脸的半径
    var faceRadius:CGFloat {
        return min(bounds.size.width, bounds.size.height) / 2 * scale
    }

    weak var dataSource: FaceViewDataSource?

    // 缩放
    func scale(gesture:UIPinchGestureRecognizer){
        if gesture.state == .Changed{
            scale *= gesture.scale
            gesture.scale = 1
        }
    }

    override func drawRect(rect: CGRect) {
        let facePath = UIBezierPath(arcCenter: faceCenter, radius: faceRadius, startAngle: 0, endAngle:CGFloat(2 * M_PI), clockwise: true)

        facePath.lineWidth = lineWidth
        color.set()
        facePath.stroke()

        bezierPathForEye(.Left).stroke()
        bezierPathForEye(.Right).stroke()

        // 此处改变笑脸弧度
        let smiliness = dataSource?.smilinessForFaceView(self) ?? 0.0
        let smilePath = bezierPathForSmile(smiliness)
        smilePath.stroke()
    }

    private struct Scaling {
        static let FaceRadiusToEyeRadiusRatio:CGFloat = 10
        static let FaceRadiusToEyeOffsetRatio:CGFloat = 3
        static let FaceRadiusToEyeSeparationRatio:CGFloat = 1.5
        static let FaceRadiusToMouthWidthRatio:CGFloat = 1
        static let FaceRadiusToMouthHeightRatio:CGFloat = 3
        static let FaceRadiusToMouthOffsetRatio:CGFloat = 3
    }
    private enum Eye {case Left,Right}

    // 画眼睛
    private func bezierPathForEye(whichEye:Eye) -> UIBezierPath{
        let eyeRadius = faceRadius / Scaling.FaceRadiusToEyeRadiusRatio
        let eyeVerticaloffset = faceRadius / Scaling.FaceRadiusToEyeOffsetRatio
        let eyeHorizontalSeparation = faceRadius / Scaling.FaceRadiusToEyeSeparationRatio

        var eyeCenter = faceCenter
        eyeCenter.y -= eyeVerticaloffset

        switch whichEye {
        case .Left: eyeCenter.x -= eyeHorizontalSeparation / 2
        case .Right: eyeCenter.x += eyeHorizontalSeparation / 2
        default :break
        }

        let path = UIBezierPath(arcCenter: eyeCenter, radius: eyeRadius, startAngle: 0, endAngle:CGFloat(2*M_PI), clockwise: true)

        path.lineWidth = lineWidth
        return path
    }

    // 画嘴角弧度
    private func bezierPathForSmile(fractionOfmaxSmile:Double ) -> UIBezierPath{
        let mouthWidth = faceRadius / Scaling.FaceRadiusToMouthWidthRatio
        let mouthHeight = faceRadius / Scaling.FaceRadiusToMouthHeightRatio
        let mouthVerticalOffset = faceRadius / Scaling.FaceRadiusToMouthOffsetRatio

        let smileheight = CGFloat(max(min(fractionOfmaxSmile,1), -1)) * mouthHeight

        let start = CGPoint(x: faceCenter.x - mouthWidth/2, y: faceCenter.y + mouthVerticalOffset)

        let end = CGPoint(x:start.x + mouthWidth, y:start.y)
        let cp1 = CGPoint(x:start.x + mouthWidth/3, y:start.y + smileheight)
        let cp2 = CGPoint(x:end.x - mouthWidth/3, y: cp1.y)

        let path = UIBezierPath()
        path.moveToPoint(start)
        path.addCurveToPoint(end, controlPoint1: cp1, controlPoint2: cp2)
        path.lineWidth = lineWidth
        return path
    }

}