UIPanGesture recognizer swiping only in one direction - ios

Question

I am working on UIPanGestureRecognizer and to me it is working. but I have some problem here as I am new to iOS and just shifted from Android to iOS.
First take a look at what I want to do:
What I want: I have a UITableView and I want to perform swiping on the Cells. I just want to drag them from left to right side and move/Delete that cell. Pretty same like it is done in android.
But I just want to move the item only in one direction. And that is "LEFT TO RIGHT". But not from right to left. Now here take a look at what I have done so far
What I have Done:
#objc func handlePan(recognizer: UIPanGestureRecognizer) {
// 1
if recognizer.state == .began {
// when the gesture begins, record the current center location
originalCenter = center
print("Center",originalCenter)
}
// 2
if recognizer.state == .changed {
let translation = recognizer.translation(in: self)
center = CGPoint(x: originalCenter.x+translation.x, y: originalCenter.y)
// has the user dragged the item far enough to initiate a delete/complete?
deleteOnDragRelease = frame.origin.x < -frame.size.width / 2.0
completeOnDragRelease = frame.origin.x > frame.size.width / 2.0
// print ("FrameX = ",frame.origin.x , " , ","Width = ",frame.size.width / 2.0 , "Total = ",frame.origin.x < -frame.size.width / 2.0 )
//print ("DelOnDrag = ",deleteOnDragRelease , " , ","CompOnDrag = ",completeOnDragRelease)
}
// 3
if recognizer.state == .ended {
// the frame this cell had before user dragged it
let originalFrame = CGRect(x: 0, y: frame.origin.y,
width: bounds.size.width, height: bounds.size.height)
if deleteOnDragRelease {
if delegate != nil && clickedItem != nil {
// notify the delegate that this item should be deleted
delegate!.toDoItemDeleted(clickedItem: clickedItem!)
}
} else if completeOnDragRelease {
UIView.animate(withDuration: 8.2, animations: {self.frame = originalFrame})
} else {
UIView.animate(withDuration: 8.2, animations: {self.frame = originalFrame})
}
}
}
I know I can make a check on ".changed" , and calculate if the X value is going towards 0 or lesser then 0. But point is for some time it will move item from right to left.
Question: Is there any way I can get the x value of point of contact? or just some how I can get user want to swipe right to left and just stop user from doing that?? Please share your knowledge

Answer 1

your same code just one changes in your UIGestureRecognizer method replace with this code and your problem solve. only left to right side swap work on your tableview cell . any query regrading this just drop comment below.
override func gestureRecognizerShouldBegin(_ gestureRecognizer: UIGestureRecognizer) -> Bool {
if let panGestureRecognizer = gestureRecognizer as? UIPanGestureRecognizer {
let translation = panGestureRecognizer.translation(in: superview!)
if translation.x >= 0 {
return true
}
return false
}
return false
}
Good Luck.
Keep coding.

Answer 2

You can do this using below extensions
extension UIPanGestureRecognizer {
enum GestureDirection {
case Up
case Down
case Left
case Right
}
func verticalDirection(target: UIView) -> GestureDirection {
return self.velocity(in: target).y > 0 ? .Down : .Up
}
func horizontalDirection(target: UIView) -> GestureDirection {
return self.velocity(in: target).x > 0 ? .Right : .Left
}
}
And you can get direction like below
gestureRecognizer.horizontalDirection(target: self)