SkeletonViews not removed from reused table view cells

lordzsolt commented 3 years ago

Description

Describe your issue here.

What type of issue is this? (place an `x` in one of the `[ ]`)

[X] bug
[ ] enhancement (feature request)
[ ] question
[ ] documentation related
[ ] discussion

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[X] I've read and understood the Contributing guidelines and have done my best effort to follow them.
[X] I've read and agree to the Code of Conduct.
[X] I've searched for any related issues and avoided creating a duplicate issue.

Bug Report

When the table view cell gets reused, the gray skeleton view is still visible.

Tested on iPad 9.7-inch and iPhone 8 Plus.

SkeletonView Environment:

SkeletonView version: 1.13 and 1.15 Xcode version: 12.5 Swift version: 5

Steps to reproduce:

Run the project
Wait for skeletons to be hidden
Scroll down
The 8th or 9th cell will still have the gray skeleton view

Expected result:

Skeleton view is visible

Actual result:

Skeleton view is no longer visible.

Attachments:

https://github.com/lordzsolt/SkeletonView-Test

aaronvegh commented 3 years ago

I had this issue as well. Hoo boy I thought I was sunk, having just spent a day+ implementing it in this app! I was able to find a solution by implementing something like this in the UITableViewCell's prepareForReuse() method:

findViews(subclassOf: UIView.self).forEach { view in
    view.layer.sublayers?
        .filter { $0 is CAGradientLayer }
        .forEach { layer in
            layer.removeFromSuperlayer(   
    }
}

findViews() is a UIView extension that includes these methods:

func findViews<T: UIView>(subclassOf: T.Type) -> [T] {
            return recursiveSubviews.compactMap { $0 as? T }
    }

    var recursiveSubviews: [UIView] {
        return subviews + subviews.flatMap { $0.recursiveSubviews }
    }

The point here is that I'm manually doing what I figure this framework should be doing, removing the CAGradientLayer from all the relevant views. For reasons I couldn't determine from looking at the code, this simply isn't happening. I suspect some break in the view hierarchy as the SkeletonView code is doing its job. In any event, this solves the problem for me.

lordzsolt commented 3 years ago

I had this issue as well. Hoo boy I thought I was sunk, having just spent a day+ implementing it in this app! I was able to find a solution by implementing something like this in the UITableViewCell's prepareForReuse() method:
findViews(subclassOf: UIView.self).forEach { view in
    view.layer.sublayers?
        .filter { $0 is CAGradientLayer }
        .forEach { layer in
            layer.removeFromSuperlayer(   
    }
}
findViews() is a UIView extension that includes these methods:
func findViews<T: UIView>(subclassOf: T.Type) -> [T] {
            return recursiveSubviews.compactMap { $0 as? T }
    }

    var recursiveSubviews: [UIView] {
        return subviews + subviews.flatMap { $0.recursiveSubviews }
    }
The point here is that I'm manually doing what I figure this framework should be doing, removing the CAGradientLayer from all the relevant views. For reasons I couldn't determine from looking at the code, this simply isn't happening. I suspect some break in the view hierarchy as the SkeletonView code is doing its job. In any event, this solves the problem for me.

I guess one important question at that point is.... What's the performance impact of this.

Since table views/collection views are highly sensitive to performance. Prepare for reuse happens when scrolling, and that's the moment where it's the most important that not a lot is happening, so it doesn't cause hitches.

Juanpe commented 3 years ago

Hi!

Please, check issue #399, I think this issue it's related and it could be duplicated

Juanpe commented 3 years ago

The latest version should fix this problem. Please, could you check it to close this issue?

stale[bot] commented 3 years ago

🤖 This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Thank you for your contributions 🙂

Juanpe / SkeletonView