DGElasticPullToRefresh
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gontovnik
Unable to simultaneously satisfy constraints
Hey, I try to use it whit the storyboard, but when I pull down the table view, the tableView goes away. Probably, because I use a tableView in Storyboard with constraints.. I don't know if you know what i meen :)
Hey! Could you please show me video? Could you also try on an empty project to make sure it is because of constraints? I will have a look tomorrow as well.
I tried to create an empty project: A simple viewController with inside a TableView
import UIKit
class ViewController: UIViewController {
@IBOutlet weak var testTableView: UITableView!
override func viewDidLoad() {
super.viewDidLoad()
let loadingView = DGElasticPullToRefreshLoadingViewCircle()
loadingView.tintColor = UIColor(red: 78/255.0, green: 221/255.0, blue: 200/255.0, alpha: 1.0)
testTableView.dg_addPullToRefreshWithActionHandler({ [weak self] () -> Void in
// Add your logic here
// Do not forget to call dg_stopLoading() at the end
self?.testTableView.dg_stopLoading()
}, loadingView: loadingView)
testTableView.dg_setPullToRefreshFillColor(UIColor(red: 57/255.0, green: 67/255.0, blue: 89/255.0, alpha: 1.0))
testTableView.dg_setPullToRefreshBackgroundColor(testTableView.backgroundColor!)
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
}
extension ViewController: UITableViewDataSource {
func numberOfSectionsInTableView(tableView: UITableView) -> Int {
return 1
}
func tableView(tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return 30
}
func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
let cellIdentifier = "cellIdentifier"
var cell = tableView.dequeueReusableCellWithIdentifier(cellIdentifier)
if cell == nil {
cell = UITableViewCell(style: .Default, reuseIdentifier: cellIdentifier)
cell!.contentView.backgroundColor = UIColor(red: 250/255.0, green: 250/255.0, blue: 251/255.0, alpha: 1.0)
}
if let cell = cell {
cell.textLabel?.text = "\(indexPath.row)"
return cell
}
return UITableViewCell()
}
}
// MARK: -
// MARK: UITableView Delegate
extension ViewController: UITableViewDelegate {
func tableView(tableView: UITableView, didSelectRowAtIndexPath indexPath: NSIndexPath) {
tableView.deselectRowAtIndexPath(indexPath, animated: true)
}
}
here you can see the bug, when I pull down
Ok, I found what is the issue. Now I need to find out what is the best approach to fix that. Basically, I use this trick to force stop table view scrolling:
func dg_stopScrollingAnimation() {
if let superview = self.superview, let index = superview.subviews.indexOf({ $0 == self }) as Int! {
removeFromSuperview()
superview.insertSubview(self, atIndex: index)
}
}
As we use weak references for storyboard items it becomes deallocated when we call "removeFromSuperview".
I'm having the same problem. Were you able to find a way to fix this issue?
There is one way to fix this issue, but it may cause other issues. Just comment out all in this func:
func dg_stopScrollingAnimation() {
// if let superview = self.superview, let index = superview.subviews.indexOf({ $0 == self }) as Int! {
// removeFromSuperview()
// superview.insertSubview(self, atIndex: index)
// }
}
Just tried it and it works, but there's a "flicker" problem now. Sometimes my header view on my UITableView jumps for a split second and then works as it should do. Not ideal, any ideas why the header view might cause problems?
To tell the truth, I did not test with a header view. It can actually be because of that commented stuff. If you have time, would be great if you could test with a header view but implement it programatically, without storyboard. If not, please let me know, I will do it midnight
I'm currently creating the header view programatically, here's the code for it. Only the tableView is laid out via Storyboard, but not the header view.
func tableView(tableView: UITableView, viewForHeaderInSection section: Int) -> UIView? {
let h: CGFloat = self.tableView(tableView, heightForHeaderInSection:0)
let text = self.tableView(tableView, titleForHeaderInSection: 0)
let fullFrame = CGRect(x: 0, y: 0, width: tableView.frame.width, height: h)
let label = UILabel(frame: fullFrame)
label.font = ..
label.text = ..
label.textColor = ..
label.textAlignment = .Center
let view = UIView(frame: fullFrame)
view.addSubview(label)
view.backgroundColor = ..
return view
}
I had the same problem. I took a look at dg_stopScrollingAnimation, it appears that selfis not deallocated but this code deletes all the constraints:
removeFromSuperview()
superview.insertSubview(self, atIndex: index)
Then the autolayout error makes the tableView disappear.
As you said the problem is solved by commenting the function and I did not find side effects yet.
Let's see, if you do not face any problems with commenting it out - I will remove it and update cocoapods. The purpose of that was to fix one issue when pull to refresh is loading and user tries to scroll quickly up.
Ok, I did not succeed to make that happen. But I trust you ;)
Another clean way to fix this (without updating pod manually or forking it):
extension UIScrollView {
func dg_stopScrollingAnimation() {}
}
Have a quick look on the comments above, there is a potential fix for that
I got the same problem when using auto layout and this
extension UIScrollView {
func dg_stopScrollingAnimation() {}
}
Fix the issue, but not sure whether it will cause other issue
removeFromSuperview() indeed removes all constraints, I just saw this problem occurred on my app too.
If you just want to stop the scrolling, why not call
self.setContentOffset(self.contentOffset, animated: false)
instead? Does this serve the same purpose?
@joe528 I think that method to stop scrolling is not needed at all. It just needs more testing to confirm that.
Hi all. First, congratulations to @gontovnik for this library! is awesome ! any news about this bug? Thanks
extension UIScrollView { func dg_stopScrollingAnimation() {} }
fix the issue for me, but it flickers for first time only, Any workaround for this too ?
Could this be related to auto layout universally? If you remove the tableView from it's superview all constraints are also removed. And when it is re-added it has no constraints except ones that are created automatically. That is what is creating the error that is logged.
I recently just had this issue and I had not used Storyboards. I created all constraints programmatically. Also I am not seeing any flicker and the library does work after using the fix above.
As dg_stopScrollingAnimation was deprecated, it seems like leading to this issue(https://github.com/gontovnik/DGElasticPullToRefresh/issues/47),so I have to bring dg_stopScrollingAnimation back and modify it, but I can't understand why deprecate it can lead this issue.
