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iosswiftcgaffinetransform

Swift iOS animations for Tinder-style swipe screen

I have built a screen very similar to the Tinder main screen. I have set the borders on the draggable icon and the next card loads by being animated from the top of the screen. At the moment there are 2 buttons (1 accept button, 1 reject button) and when they are pressed the card rotates and transforms out of the screen in the right direction. This function currently accomplishes this animation...

func rejectAnimation() {

    let scale = CGAffineTransformMakeScale(1, 1)
    let translate = CGAffineTransformMakeTranslation(0, 0)
    self.cardUIView.transform = CGAffineTransformConcat(scale, translate)

    springWithCompletion(0.75, animations: {

        let rotate = CGAffineTransformMakeRotation(CGFloat(-M_PI_2))
        let translate = CGAffineTransformMakeTranslation((-375), 0)
        self.cardUIView.transform = CGAffineTransformConcat(rotate, translate)

        }, completion: { finished in 0
            self.refreshView()
    })
}

and

func acceptAnimation() {

    let scale = CGAffineTransformMakeScale(1, 1)
    let translate = CGAffineTransformMakeTranslation(0, 0)
    self.cardUIView.transform = CGAffineTransformConcat(scale, translate)

    springWithCompletion(0.75, animations: {

        let rotate = CGAffineTransformMakeRotation(CGFloat(M_PI_2))
        let translate = CGAffineTransformMakeTranslation(375, 0)
        self.cardUIView.transform = CGAffineTransformConcat(rotate, translate)

        }, completion: { finished in 0
            self.refreshView()
    })
}

My question is this. How can I animate so that when the user drags a card and drops it to the outside the right or left boundaries the card continues to translate off the screen in the direction it was swiped before resetting to a new card?

Note: the springWithCompletion is a function that performs the animations within it over a certain period of time.

Solution

  • Check this out . Written in swift 4

    func beingDragged(_ gestureRecognizer: UIPanGestureRecognizer) {

    xFromCenter = gestureRecognizer.translation(in: self).x
    yFromCenter = gestureRecognizer.translation(in: self).y
    switch gestureRecognizer.state {

    case .began:
        originalPoint = self.center;
        break;

    case .changed:
        let rotationStrength = min(xFromCenter / ROTATION_STRENGTH, ROTATION_MAX)
        let rotationAngel = .pi/8 * rotationStrength
        let scale = max(1 - fabs(rotationStrength) / SCALE_STRENGTH, SCALE_MAX)
        center = CGPoint(x: originalPoint.x + xFromCenter, y: originalPoint.y + yFromCenter)
        let transforms = CGAffineTransform(rotationAngle: rotationAngel)
        let scaleTransform: CGAffineTransform = transforms.scaledBy(x: scale, y: scale)
        self.transform = scaleTransform
        updateOverlay(xFromCenter)
        break;

    case .ended:
        afterSwipeAction()
        break;

    case .possible:break
    case .cancelled:break
    case .failed:break
    }
}

    https://github.com/nickypatson/TinderSwipeView

    thanks