Passing current UITableViewCell swipe to parent UITableView - ios

Question

I have a custom UITableViewCell, which has a functionality to be swiped to the right. The swipe gesture is based on the translation of x-axis, so, when the translation of x is exceeded 40 points, I want to trigger a segue.
I think this is a perfect place to use delegates to pass data about the current X value. So, I have created a protocol with a function didSwipeCell(), but I'm not sure how to pass the current x value to the UITableView.
Please let me know how to do it, and if you need any extra info, please let me know in the comment instead of downvoting.

Answer 1

Add x value as a parameter of didSwipeCell() method
protocol TableViewCellDelegate {
func didSwipeCell(on xValue: Float)
}
Add the delegate instance to your cell
class TableViewCell: UITableViewCell {
weak var delegate: TableViewCellDelegate?
}
Then, call the method when user swipes the cell giving xValue
delegate?.didSwipeCell(on: xValue)
In your UITableView implement TableViewCellDelegate method.
class TableView: UITableView, TableViewCellDelegate {
func didSwipeCell(on xValue: Float) {
//here you can get the xValue
}
And, do not forget to set the delegate of TableViewCell in your cellForRowAtIndexPath method
cell.delegate = self

Answer 2

You can get value of x simply from your UItableViewCell Class to your UIViewController. Declare closure
var getValue: ((_ xValue: CGFloat)->())!
in your UItableViewCell Class and implement it into your UIViewController Class.
In ViewController
cell. getValue = { (xValue) in
// do what you want to do
}

Answer 3

Here is another way to do it...
class SwipeTableViewCell: UITableViewCell {
var didSwipeAction : ((CGFloat)->())?
var startLocation = CGPoint.zero
var theSwipeGR: UISwipeGestureRecognizer?
func respondToSwipeGesture(_ sender: UIGestureRecognizer) {
if let swipe = sender as? UISwipeGestureRecognizer {
if (swipe.state == UIGestureRecognizerState.began) {
startLocation = swipe.location(in: self.contentView);
} else if (swipe.state == UIGestureRecognizerState.ended) {
let stopLocation = swipe.location(in: self.contentView);
let dx = stopLocation.x - startLocation.x;
if dx > 40 {
// pass the ending X coordinate in the callback
didSwipeAction?(stopLocation.x)
}
}
}
}
override init(style: UITableViewCellStyle, reuseIdentifier: String?) {
super.init(style: style, reuseIdentifier: reuseIdentifier)
myInit()
}
required init?(coder aDecoder: NSCoder) {
super.init(coder: aDecoder)
myInit()
}
func myInit() -> Void {
if theSwipeGR == nil {
let g = UISwipeGestureRecognizer(target: self, action: #selector(respondToSwipeGesture(_:)))
g.direction = UISwipeGestureRecognizerDirection.right
self.contentView.addGestureRecognizer(g)
theSwipeGR = g
}
}
}
and then your table view cell setup becomes:
override func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCell(withIdentifier: "SwipeCell", for: indexPath) as! SwipeTableViewCell
cell.didSwipeAction = {
(xValue) in
print("Simple", indexPath, "X =", xValue)
// call performSegue() or do something else...
}
return cell
}