UISwipeGestureRecognizer动画

Question

I'm trying to implement an UISwipeGestureRecognizer in my collectionViewCell, so when you swipe to the left, the cell disappear. What i'm trying to implement (i can't find a way to do it) is to animate the swipe, so when i swipe the cell to the left, it disappears with a fade effect. This is the code i have inside the method cellForItemAtindexPath

let cSelector = #selector(reset(sender:))
    let UpSwipe = UISwipeGestureRecognizer(target: self, action: cSelector)
    UpSwipe.direction = UISwipeGestureRecognizerDirection.left
    cell.addGestureRecognizer(UpSwipe)

The method

 func reset(sender: UISwipeGestureRecognizer) {

    let cell = sender.view as! UICollectionViewCell
    let i = self.collectionView?.indexPath(for: cell)!.item


    self.messages.remove(at: i!)
    self.collectionView?.reloadData()

}

Thanks!!!

EDIT: I think i found an easiest way to do it, but i'm having some troubles. I tried implementing a UIPanGestureRecognizer in the cell. This is how it looks like...

cellForItemAt

let gestureRecognizer = UIPanGestureRecognizer(target: self, action: #selector(handlePan(gestureRecognizer:)))
    cell.addGestureRecognizer(gestureRecognizer)

The method

func handlePan(gestureRecognizer: UIPanGestureRecognizer) {
    if gestureRecognizer.state == .began {
        // When the drag is first recognized, you can get the starting coordinates here

    }

    if gestureRecognizer.state == .changed {
        let translation = gestureRecognizer.translation(in: self.view)
        // Translation has both .x and .y values

        if translation.x == translation.x - 100 {
            //Method i putted before
            reset(sender: gestureRecognizer)
        }

        //print(translation.x, translation.y)
    }
}

I'm trying to locate the coordinates of the cell, so when it's in a point at the left of the cell, the cell stars some kind of fade animation, and then disappear.

Any help??? Thanks!!!

Answer 1

There are two options to achieve your goal.

1. Create custom layout
2. Use UIView with swipe gesture

Create custom layout
You can create a custom layout according to your choice of animation. Here is reference. You just need to modify its animation.

Use UIView with Swipe Gesture
Follow these steps

• Add UIView (var name - swipeView ) in CollectionView Cell & set background color for UIView.
• Add Swipe Gesture (left and/or right)to swipeView
• Handle swipe of view along with user's drag operation using different states of swipe gesture (begin, drag, end).
• When swipe gesture end, push swipeView out side your cell with animation (set x position of them such that it can go out of bounds of cell frame)
• Remove element from array and reload collection view.

I hope, with above logic you can do what you want and you may not need readymade code.

Answer 2

So i tried this code, and it works fine for me!

func setupView(){
    // Setting up swipe gesture recognizers
    let swipeUp : UISwipeGestureRecognizer = UISwipeGestureRecognizer(target: self, action: #selector(userDidSwipeUp(_:)))
    swipeUp.direction = .left

    collectionView?.addGestureRecognizer(swipeUp)

    //let swipeDown : UISwipeGestureRecognizer = UISwipeGestureRecognizer(target: self, action: #selector(userDidSwipeDown))
    //swipeDown.direction = .right

    //collectionView?.addGestureRecognizer(swipeDown)
}


func getCellAtPoint(_ point: CGPoint) -> ChatMessageCell? {
    // Function for getting item at point. Note optionals as it could be nil
    let indexPath = collectionView?.indexPathForItem(at: point)
    var cell : ChatMessageCell?

    if indexPath != nil {
        cell = collectionView?.cellForItem(at: indexPath!) as? ChatMessageCell
    } else {
        cell = nil
    }

    return cell
}

func userDidSwipeUp(_ gesture : UISwipeGestureRecognizer) {

    let point = gesture.location(in: collectionView)  //collectionview
    let duration = animationDuration()                //0.5

    if(cell == nil){
        cell = getCellAtPoint(point)

        UIView.animate(withDuration: duration, animations: {
            //self.activeCell.myCellView.transform = CGAffineTransform(translationX: 0, y: -self.activeCell.frame.height)
            self.cell.celdaNormal.transform = CGAffineTransform(translationX: -self.cell.frame.width , y: 0)

        })

    }  else {
        // Getting the cell at the point
        let cell = getCellAtPoint(point)

        // If the cell is the previously swiped cell, or nothing assume its the previously one.
        if cell == nil || cell == cell {
            // To target the cell after that animation I test if the point of the swiping exists inside the now twice as tall cell frame
            let cellFrame = cell?.frame

            var rect = CGRect()

            if cell != nil {
                rect = CGRect(x: (cellFrame?.origin.x)! - (cellFrame?.width)!, y: (cellFrame?.origin.y)!, width: (cellFrame?.width)!*2, height: (cellFrame?.height)!)
            }

            if rect.contains(point) {
                // If swipe point is in the cell delete it

                let indexPath = collectionView?.indexPath(for: cell!)
                messages.remove(at: indexPath!.row)
                collectionView?.deleteItems(at: [indexPath!])

                if messages.count == 0 {
                    reusableView.etiqueta.isHidden = true
                }
            }
            // If another cell is swiped
        }
}

func animationDuration() -> Double {
    return 0.5
}

All you have to do, is call the setupView() in viewDidLoad, and that's it! I have to mention that i modified the code from this question... Swipe to delete on CollectionView