Swift: Wie kann man nach dem Verschieben (Ziehen) eine gleichmäßige Trägheit erzeugen?

Question

Ich habe Swift 2.2 seit mehreren Tagen gelernt. Nachdem ich das offizielle Tutorial beendet habe, versuche ich einige funktionale Beispiele zu erstellen. Z.B. Ich versuche, einen Avatar Dekorateur zu machen.

@IBAction func moveAvatar(recognizer:UIPanGestureRecognizer) { 
    recognizer.maximumNumberOfTouches = 1 
    recognizer.minimumNumberOfTouches = 1 
    let debugOutOfBounds = false 
    let debugGestureRecognizer = false 
    let debugVelocity = true 
    if (debugGestureRecognizer) { 
     print("pan") 
    } 
    let translation = recognizer.translationInView(self.avatar) 

    let standardAvatarSize:CGFloat = Conf.Size.avatarRadius * 2 
    if (self.avatar.frame.width < standardAvatarSize) { 
     self.avatar.frame = CGRect(origin: self.avatar.frame.origin, size: CGSize(width: standardAvatarSize, height:standardAvatarSize)) 
    } 
    if let view = recognizer.view { 
     switch recognizer.state { 
     case .Began: 
      if (debugVelocity) { 
       print("Began: velocity: \(recognizer.velocityInView(view)) translation: \(translation)") 
      } 

      self.panAvatarLastTranslation = translation 
      self.avatar.center = CGPoint(x: self.avatar.center.x + translation.x, y: self.avatar.center.y + translation.y) 
     case .Changed: 
      if (debugVelocity) { 
       print("Changed: velocity: \(recognizer.velocityInView(view)) translation: \(translation)") 
      } 
      if (translation != CGPoint(x: 0.0, y: 0.0)) { 
       self.panAvatarLastTranslation = translation 
      } 
      self.avatar.center = CGPoint(x: self.avatar.center.x + translation.x, y: self.avatar.center.y + translation.y) 
     case .Ended: 
      if (debugVelocity) { 
       print("Ended: velocity: \(recognizer.velocityInView(view)) translation: \(translation)") 
      } 
      let velocityDistance = sqrt(pow(recognizer.velocityInView(view).x, CGFloat(2)) + pow(recognizer.velocityInView(view).y, CGFloat(2))) 
      print(velocityDistance) 
      if (velocityDistance > 100) { 
       let inertiaDelay: NSTimeInterval = 0.5 
       let inertiaDistance : CGFloat = velocityDistance * CGFloat(inertiaDelay) * 0.02 
       let inertiaX:CGFloat = self.panAvatarLastTranslation.x * inertiaDistance 
       let inertiaY:CGFloat = self.panAvatarLastTranslation.y * inertiaDistance 
            //sqrt(pow(inertiaX, CGFloat(2)) + pow(inertiaY, CGFloat(2))) 
       //print("inertiaDelay: \(inertiaDelay)") 
       UIView.animateWithDuration(inertiaDelay, animations: { 
        self.avatar.center.x += inertiaX 
        self.avatar.center.y += inertiaY 
       }) 
      } 
     default: 
      print("default") 
     } 

     let standardAvatarBound: [String:CGFloat] = [ 
      "top": UIApplication.sharedApplication().statusBarFrame.height + UIScreen.mainScreen().bounds.width/2 - Conf.Size.avatarRadius, 
      "right": UIScreen.mainScreen().bounds.width/2 + Conf.Size.avatarRadius, 
      "bottom": UIApplication.sharedApplication().statusBarFrame.height + UIScreen.mainScreen().bounds.width/2 + Conf.Size.avatarRadius, 
      "left": UIScreen.mainScreen().bounds.width/2 - Conf.Size.avatarRadius 
     ] 
     let avatarBound: [String:CGFloat] = [ 
      "top": self.avatar.center.y - self.avatar.frame.height/2, 
      "right": self.avatar.frame.width/2 + self.avatar.center.x, 
      "bottom": self.avatar.center.y + self.avatar.frame.height/2, 
      "left": self.avatar.center.x - self.avatar.frame.width/2 
     ] 

     if (self.panAvatarLastTranslation.x < 0 && avatarBound["right"] < standardAvatarBound["right"]) { 
      UIView.animateWithDuration(0.5, animations: { 
       self.avatar.center.x += (standardAvatarBound["right"]! - avatarBound["right"]!) 
      }) 
      if (debugOutOfBounds) { 
       print("Out of right bound") 
      } 
     } 

     if(self.panAvatarLastTranslation.x > 0 && avatarBound["left"] > standardAvatarBound["left"]) { 
      UIView.animateWithDuration(0.5, animations: { 
       self.avatar.center.x -= (avatarBound["left"]! - standardAvatarBound["left"]!) 
      }) 
      if (debugOutOfBounds) { 
       print("Out of left bound") 
      } 
     } 

     if(self.panAvatarLastTranslation.y > 0 && avatarBound["top"] > standardAvatarBound["top"]) { 
      UIView.animateWithDuration(0.5, animations: { 
       self.avatar.center.y -= (avatarBound["top"]! - standardAvatarBound["top"]!) 
      }) 
      if (debugOutOfBounds) { 
       print("Out of top bound") 
      } 
     } 
     if(self.panAvatarLastTranslation.y < 0 && avatarBound["bottom"] < standardAvatarBound["bottom"]) { 
      UIView.animateWithDuration(0.5, animations: { 
       self.avatar.center.y += (standardAvatarBound["bottom"]! - avatarBound["bottom"]!) 
      }) 
      if (debugOutOfBounds) { 
       print("Out of bottom bound") 
      } 
     } 
    } 
    recognizer.setTranslation(CGPointZero, inView: view) 
} 

Okay, wie man sehen kann, dass ich Handhabung Trägheit Ziehen im „.Ended“ Zustand der Pfanne Gestenerkenner. Es funktioniert gut, aber nicht glatt. Was kann ich tun, um eine glatte Schwenkträgheit zu erreichen? Hier

ist der Quellcode: https://github.com/AarioAi/NotesOpen/tree/master/Swift

Answer 1

Probieren Sie verschiedene Methode zum Animieren. Heck this tutorial