UIPanGesture not moving individual view - ios

Question

I am doing a iPhone project in Swift where on top of my homeScreen, I am adding multiple views in a stack.
My requirement is to be able to move each individual child view on top of the homeScreen like Tinder card swiping effect. I am using UIPanGesture to achieve this so that the each individual view follows my finger on screen.
But my problem is that instead of the desired effect of moving only one screen all the stack of Views is moving together on my Home Screen.
I am stuck at this problem for the last 4 days. Kindly help me out.
Xcode Version 7.2.1 and Swift 2.1
Here is the code that moves the UIView:
//For creating each childView and adding UIPanGestureRecognizer to each childView
func configureInitialViewPlacement() -> Void {
for var i:Int = cardsArray.count-1; 0 <= i; i--
{
let cardView = cardsArray[i]
let panGestureRecognizer = UIPanGestureRecognizer(target: self, action: "beingDragged:")
cardView.addGestureRecognizer(panGestureRecognizer)
self.view.addSubview(cardView)
var frame = CGRectZero
var originalFrame = self.view.bounds
originalFrame = CGRectMake(originalFrame.origin.x+10,originalFrame.origin.y+10 , originalFrame.size.width-20, originalFrame.size.height-20)
frame.size.height = originalFrame.size.height
frame.size.width = originalFrame.size.width - CGFloat((2*CGFloat(i)*paddingOffset))
frame.origin.x = originalFrame.origin.x + CGFloat((CGFloat(i)*paddingOffset))
frame.origin.y = originalFrame.origin.y + CGFloat((CGFloat(i)*paddingOffset))
cardView.frame = frame
cardView.setContentViewForCard(cardDataArray[i])
}
}
// Method For gestureRecognizer
func beingDragged(gestureRecognizer: UIPanGestureRecognizer) -> Void {
xFromCenter = Float(gestureRecognizer.translationInView(self.view).x)
yFromCenter = Float(gestureRecognizer.translationInView(self.view).y)
switch gestureRecognizer.state {
case UIGestureRecognizerState.Began:
self.originPoint = self.view.center
case UIGestureRecognizerState.Changed:
let rotationStrength: Float = min(xFromCenter/ROTATION_STRENGTH, ROTATION_MAX)
let rotationAngle = ROTATION_ANGLE * rotationStrength
let scale = max(1 - fabsf(rotationStrength) / SCALE_STRENGTH, SCALE_MAX)
self.view.center = CGPointMake(self.originPoint.x + CGFloat(xFromCenter), self.originPoint.y + CGFloat(yFromCenter))
let transform = CGAffineTransformMakeRotation(CGFloat(rotationAngle))
let scaleTransform = CGAffineTransformScale(transform, CGFloat(scale), CGFloat(scale))
self.view.transform = scaleTransform
self.updateOverlay(CGFloat(xFromCenter))
case UIGestureRecognizerState.Ended:
self.afterSwipeAction()
case UIGestureRecognizerState.Possible:
fallthrough
case UIGestureRecognizerState.Cancelled:
fallthrough
case UIGestureRecognizerState.Failed:
fallthrough
default:
break
}
}
func afterSwipeAction() -> Void {
let floatXFromCenter = Float(xFromCenter)
if floatXFromCenter > ACTION_MARGIN {
self.rightAction()
} else if floatXFromCenter < -ACTION_MARGIN {
self.leftAction()
} else {
UIView.animateWithDuration(0.3, animations: {() -> Void in
self.view.center = self.originPoint
self.view.transform = CGAffineTransformMakeRotation(0)
})
}
}
// For Right Swipe
func rightAction() -> Void {
let finishPoint: CGPoint = CGPointMake(500, 2 * CGFloat(yFromCenter) + self.originPoint.y)
UIView.animateWithDuration(0.3,
animations: {
self.view.center = finishPoint
}, completion: {
(value: Bool) in
self.cardsArray[0].removeFromSuperview()
})
delegateforcard.cardSwipedRight(self.cardsArray[0])
}
// For Left Swipe
func leftAction() -> Void {
let finishPoint: CGPoint = CGPointMake(-500, 2 * CGFloat(yFromCenter) + self.originPoint.y)
UIView.animateWithDuration(0.3,
animations: {
self.view.center = finishPoint
}, completion: {
(value: Bool) in
self.cardsArray[0].removeFromSuperview()
})
delegateforcard.cardSwipedLeft(self.cardsArray[0])
}
Let me know if you need more clarifications.
Thanks.

Answer 1

I have also done the same in objective-c, You can get an idea from here,
Here is my code
UIPanGestureRecognizer *panGestureRecognizer = [[UIPanGestureRecognizer alloc]initWithTarget:self action:#selector(cardMoving:)];
-(void)cardMoving:(UIPanGestureRecognizer *)gestureRecognizer
{
xValueFromCenter = [gestureRecognizer translationInView:self].x; // if right positive(+) value, negative for left
yValueFromCenter = [gestureRecognizer translationInView:self].y; // if swipe up positive(+), negative for down
switch (gestureRecognizer.state) {
case UIGestureRecognizerStateBegan:{
originalPoint = self.center;
break;
};
case UIGestureRecognizerStateChanged:{
CGFloat rotationStrength = MIN(xValueFromCenter / ROTATION_STRENGTH, ROTATION_MAX);
CGFloat rotationAngel = (CGFloat) (ROTATION_ANGLE * rotationStrength);
CGFloat scale = MAX(1 - fabs(rotationStrength) / SCALE_STRENGTH, SCALE_MAX);
self.center = CGPointMake(originalPoint.x + xValueFromCenter, originalPoint.y + yValueFromCenter);
CGAffineTransform transform = CGAffineTransformMakeRotation(rotationAngel);
CGAffineTransform scaleTransform = CGAffineTransformScale(transform, scale, scale);
self.transform = scaleTransform;
[self updateOverlay:xValueFromCenter];
break;
};
case UIGestureRecognizerStateEnded: {
[self afterSwipeAction];
break;
};
case UIGestureRecognizerStatePossible:break;
case UIGestureRecognizerStateCancelled:break;
case UIGestureRecognizerStateFailed:break;
}
}
-(void)updateOverlay:(CGFloat)distance
{
if (distance > 0) {
overlayView.Direction = GGOverlayViewDirectionRight;
} else {
overlayView.Direction = GGOverlayViewDirectionLeft;
}
overlayView.alpha = MIN(fabs(distance)/100, 0.7);
}
- (void)afterSwipeAction
{
if (xValueFromCenter > ACTION_MARGIN) {
[self rightAction];
} else if (xValueFromCenter < -ACTION_MARGIN) {
[self leftAction];
} else { //for reseting the card
[UIView animateWithDuration:0.3
animations:^{
self.center = originalPoint;
self.transform = CGAffineTransformMakeRotation(0);
overlayView.alpha = 0;
}];
}
}