Weird uitableview behaviour in iOS11. Cells scroll up with navigation push animation - ios

I have recently migrated some code to new iOS 11 beta 5 SDK.
I now get a very confusing behaviour from UITableView. The tableview itself is not that fancy. I have custom cells but in most part it is just for their height.
When I push my view controller with tableview I get an additional animation where cells "scroll up" (or possibly the whole tableview frame is changed) and down along push/pop navigation animation. Please see gif:
I manually create tableview in loadView method and setup auto layout constraints to be equal to leading, trailing, top, bottom of tableview's superview. The superview is root view of view controller.
View controller pushing code is very much standard: self.navigationController?.pushViewController(notifVC, animated: true)
The same code provides normal behaviour on iOS 10.
Could you please point me into direction of what is wrong?
EDIT: I have made a very simple tableview controller and I can reproduce the same behavior there. Code:
class VerySimpleTableViewController : UITableViewController {
override func viewDidLoad() {
super.viewDidLoad()
self.tableView.register(UITableViewCell.self, forCellReuseIdentifier: "Cell")
}
override func numberOfSections(in tableView: UITableView) -> Int {
return 1
}
override func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return 4
}
override func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCell(withIdentifier: "Cell", for: indexPath)
cell.textLabel?.text = String(indexPath.row)
cell.accessoryType = .disclosureIndicator
return cell
}
override func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {
tableView.deselectRow(at: indexPath, animated: true)
let vc = VerySimpleTableViewController.init(style: .grouped)
self.navigationController?.pushViewController(vc, animated: true)
}
}
EDIT 2: I was able to narrow issue down to my customisation of UINavigationBar. I have a customisation like this:
rootNavController.navigationBar.setBackgroundImage(createFilledImage(withColor: .white, size: 1), for: .default)
where createFilledImage creates square image with given size and color.
If I comment out this line I get back normal behaviour.
I would appreciate any thoughts on this matter.

This is due to UIScrollView's (UITableView is a subclass of UIScrollview) new contentInsetAdjustmentBehavior property, which is set to .automatic by default.
You can override this behavior with the following snippet in the viewDidLoad of any affected controllers:
tableView.contentInsetAdjustmentBehavior = .never
https://developer.apple.com/documentation/uikit/uiscrollview/2902261-contentinsetadjustmentbehavior

In addition to maggy's answer
OBJECTIVE-C
if (#available(iOS 11.0, *)) {
scrollViewForView.contentInsetAdjustmentBehavior = UIScrollViewContentInsetAdjustmentNever;
}
This issue was caused by a bug in iOS 11 where the safeAreaInsets of
the view controller's view were set incorrectly during the navigation
transition, which should be fixed in iOS 11.2. Setting the
contentInsetAdjustmentBehavior to .never isn't a great workaround
because it will likely have other undesirable side effects. If you do
use a workaround you should make sure to remove it for iOS versions >=
11.2
-mentioned by smileyborg (Software Engineer at Apple)

You can edit this behavior at once throughout the application by using NSProxy in for example didFinishLaunchingWithOptions:
if (#available(iOS 11.0, *)) {
[UIScrollView appearance].contentInsetAdjustmentBehavior = UIScrollViewContentInsetAdjustmentNever;
}

Here's how I managed to fix this issue while still allowing iOS 11 to set insets automatically. I am using UITableViewController.
Select "Extend edges under top bars" and "Extend edges under opaque bars" in your view controller in storyboard (or programmatically). The safe area insets will prevent your view from going under the top bar.
Check the "Insets to Safe Area" button on your table view in your storyboard. (or tableView.insetsContentViewsToSafeArea = true) - This might not be necessary but it's what I did.
Set the content inset adjustment behavior to "Scrollable Axes" (or tableView.contentInsetAdjustmentBehavior = .scrollableAxes) - .always might also work but I did not test.
One other thing to try if all else fails:
Override viewSafeAreaInsetsDidChange UIViewController method to get the table view to force set the scroll view insets to the safe area insets. This is in conjunction with the 'Never' setting in Maggy's answer.
- (void)viewSafeAreaInsetsDidChange {
[super viewSafeAreaInsetsDidChange];
self.tableView.contentInset = self.view.safeAreaInsets;
}
Note: self.tableView and self.view should be the same thing for UITableViewController

This seems more like a bug than intended behavior. It happens when navigation bar is not translucent or when background image is set.
If you just set contentInsetAdjustmentBehavior to .never, content insets won't be set correctly on iPhone X, e.g. content would go into bottom area, under the scrollbars.
It is necessary to do two things:
1. prevent scrollView animating up on push/pop
2. retain .automatic behaviour because it is needed for iPhone X. Without this e.g. in portrait, content will go below bottom scrollbar.
New simple solution: in XIB: Just add new UIView on top of your main view with top, leading and trailing to superview and height set to 0. You don't have to connect it to other subviews or anything.
Old solution:
Note: If you are using UIScrollView in landscape mode, it still doesn't set horizontal insets correctly(another bug?), so you must pin scrollView's leading/trailing to safeAreaInsets in IB.
Note 2: Solution below also has problem that if tableView is scrolled to the bottom, and you push controller and pop back, it will not be at the bottom anymore.
override func viewDidLoad()
{
super.viewDidLoad()
// This parts gets rid of animation when pushing
if #available(iOS 11, *)
{
self.tableView.contentInsetAdjustmentBehavior = .never
}
}
override func viewDidDisappear(_ animated: Bool)
{
super.viewDidDisappear(animated)
// This parts gets rid of animation when popping
if #available(iOS 11, *)
{
self.tableView.contentInsetAdjustmentBehavior = .never
}
}
override func viewDidAppear(_ animated: Bool)
{
super.viewDidAppear(animated)
// This parts sets correct behaviour(insets are correct on iPhone X)
if #available(iOS 11, *)
{
self.tableView.contentInsetAdjustmentBehavior = .automatic
}
}

I can reproduce the bug for iOS 11.1 but it seems that the bug is fixed since iOS 11.2.
See http://openradar.appspot.com/34465226

please make sure along with above code, add additional code as follows. It solved the problem
override func viewDidLayoutSubviews() {
super.viewDidLayoutSubviews()
tableView.contentInset = UIEdgeInsets(top: 0, left: 0, bottom: 0, right: 0) // print(thisUISBTV.adjustedContentInset)
}

Also if you use tab bar, bottom content inset of the collection view will be zero. For this, put below code in viewDidAppear:
if #available(iOS 11, *) {
tableView.contentInset = self.collectionView.safeAreaInsets
}

In my case this worked (put it in viewDidLoad):
self.navigationController.navigationBar.translucent = YES;

Removing extra space at top of collectionView or tableView
if #available(iOS 11.0, *) {
collectionView.contentInsetAdjustmentBehavior = .never
//tableView.contentInsetAdjustmentBehavior = .never
} else {
automaticallyAdjustsScrollViewInsets = false
}
Above code collectionView or tableView goes under navigation bar.
Below code prevent the collection view to go under the navigation
self.edgesForExtendedLayout = UIRectEdge.bottom
but I love to use below logic and code for the UICollectionView
Edge inset values are applied to a rectangle to shrink or expand the
area represented by that rectangle. Typically, edge insets are used
during view layout to modify the view’s frame. Positive values cause
the frame to be inset (or shrunk) by the specified amount. Negative
values cause the frame to be outset (or expanded) by the specified
amount.
collectionView.contentInset = UIEdgeInsets(top: -30, left: 0, bottom: 0, right: 0)
//tableView.contentInset = UIEdgeInsets(top: -30, left: 0, bottom: 0, right: 0)
The best way for UICollectionView
func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, insetForSectionAt section: Int) -> UIEdgeInsets {
return UIEdgeInsets(top: -30, left: 0, bottom: 0, right: 0)
}

Delete this code work for me
self.edgesForExtendedLayout = UIRectEdgeNone

if #available(iOS 11, *) {
self.edgesForExtendedLayout = UIRectEdge.bottom
}
I was using UISearchController with custom resultsControllers that has table view. Pushing new controller on results controller caused tableview to go under search.
The code listed above totally fixed the problem

Related

IOS 11: UICollectionView on iPhone X is sized wrong

I have a collection view that the frame appears too tall on the iPhone X. On every other device, the sizing and scrolling works properly as shown below:
However on iPhone X, it looks like this:
The top row is cut off, and it does not scroll all the way down to the last row. Somehow, the sizing correctly calculates the width but not the height, which is about 70 pixels too tall. (I'm not worried about the top and bottom bars. I'll fix those later)
I'm guessing this has something to do with the inset adjustments for the iPhone X screen, but I can't figure out how to fix it. I've tried this in where I size the collection view:
if #available(iOS 11.0, *) {
collectionView.contentInsetAdjustmentBehavior = .always
}
However, I can't seem to fix it.
Edit:
To clarify, the set up for this menu is as follows, there are actually two collection views onscreen. The first scrolls horizontally with paging enabled so that it locks onto each cell. The other collection views are the cells for the first one, and they scroll vertically. We'll call these subCollectionViews.
The subCollectionViews are receiving a size from the original collection view thats too tall. On the storyboard, the collection view's height is defined with respect to the top bar and the bottom paging bar as flush. In the story board, the height of the collection view is about 70 pixels larger than the calculated height during runtime.
So for the cell's layout guide:
override func awakeFromNib() {
cellImage = UIImageView(frame: contentView.frame)
cellImage?.contentMode = .scaleAspectFill
cellImage?.clipsToBounds = true
contentView.addSubview(cellImage!)
}
and for the collection view's layout:
layout.scrollDirection = .vertical
layout.minimumLineSpacing = 8
layout.minimumInteritemSpacing = 8
for the storyboard presets:
I think this is what y'all asked for. If there's anything you need to see, just ask.
I also facing this issue. Need to called safeAreaLayoutGuide for control the size of item.
func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, sizeForItemAt indexPath: IndexPath) -> CGSize {
if #available(iOS 11.0, *) {
return view.safeAreaLayoutGuide.layoutFrame.size
} else {
// Fallback on earlier versions
return view.frame.size
}
}
Add below lines of code. I think it will solve your problem.
override func viewWillAppear(_ animated: Bool) {
super.viewWillAppear(animated)
self.aCollectionVew.setNeedsLayout()
self.aCollectionVew.layoutIfNeeded()
}
Please take all traits, spacing and contentInsetAdjustmentBehavior.
Happy Coding...:)

Expand UITableView to show all cells in Stack View?

I am having trouble getting my UITableView to appear full height in my Stack View.
My view tree looks as follows:
- View
- Scroll View
- Stack View
- Table View
- Image View
- Map View
The table view is dynamically populated with data, which works fine. The issue is that only one row is visible at a time and I have to scroll through the list. What I would like to see happen is for the table view to take as much vertical room as it needs to display all the cells.
I did try adjusting table height as follows, but that just ends up with table that no longer scrolls, though even if it did work I would rather have something more dynamic:
override func viewDidAppear(animated: Bool) {
super.viewDidAppear(animated)
self.detailsTableView.frame.size.height = 200
}
I am suspecting that it is probably an aspect of the 'stack view' that needs adjusting, but I am not sure at this point. Can anyone suggest an appropriate way?
I had been encountering the same issue and realized you need a self sizing table view. I stumbled on this answer and created a subclass like #MuHAOS suggested. I did not encounter any issues.
final class IntrinsicTableView: UITableView {
override var contentSize: CGSize {
didSet {
invalidateIntrinsicContentSize()
}
}
override var intrinsicContentSize: CGSize {
layoutIfNeeded()
return CGSize(width: UIView.noIntrinsicMetric, height: contentSize.height)
}
}
A UIStackView will compress views wherever it can, to counteract this set a height anchor and width anchor to the UITableView or a priority for its height and width. Here is a working example of how we can be in charge of the dimensions of a table within a stack view.
An extension to instantiate and centrally position the UIStackView
First of all I've written a UIStackView extension so that I don't need to include all the code inside the view controller. Your positioning and setup will be different because you are placing your stack view inside a scroll view, but separating this code out means you can make your own adjustments.
extension UIStackView {
convenience init(axis:UILayoutConstraintAxis, spacing:CGFloat) {
self.init()
self.axis = axis
self.spacing = spacing
self.translatesAutoresizingMaskIntoConstraints = false
}
func anchorStackView(toView view:UIView, anchorX:NSLayoutXAxisAnchor, equalAnchorX:NSLayoutXAxisAnchor, anchorY:NSLayoutYAxisAnchor, equalAnchorY:NSLayoutYAxisAnchor) {
view.addSubview(self)
anchorX.constraintEqualToAnchor(equalAnchorX).active = true
anchorY.constraintEqualToAnchor(equalAnchorY).active = true
}
}
We don't set a size for the UIStackView only a position, it is the things contained within it that determine its size. Also note the setting of translatesAutoresizingMaskIntoConstraints to false in the UIStackView extension. (It is only required that we set this property for the stack view, its subviews simply inherit the behaviour.)
UITableView class with data source code
Next I've created a basic table class for demo purposes.
class MyTable: UITableView, UITableViewDataSource {
let data = ["January","February","March","April","May","June","July","August","September","October","November","December"]
func tableView(tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return data.count
}
func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCellWithIdentifier("SauceCell", forIndexPath: indexPath)
cell.textLabel?.text = data[indexPath.row]
return cell
}
}
Setup of stack view and table in view controller
Finally, the important stuff. As soon as we add our table to the stack view all the frame information is disregarded. So we need the final two lines of code to set the width and height for the table in terms that Auto Layout can understand.
class ViewController: UIViewController {
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view, typically from a nib.
let table = MyTable(frame: CGRect(x: 0, y: 0, width: view.frame.width, height: view.frame.height))
table.registerClass(UITableViewCell.self, forCellReuseIdentifier: "SauceCell")
table.dataSource = table
let stack = UIStackView(axis: .Vertical, spacing: 10)
stack.anchorStackView(toView: view, anchorX: stack.centerXAnchor, equalAnchorX: view.centerXAnchor, anchorY: stack.centerYAnchor, equalAnchorY: view.centerYAnchor)
stack.addArrangedSubview(table)
table.widthAnchor.constraintEqualToAnchor(view.widthAnchor, multiplier: 1).active = true
table.heightAnchor.constraintEqualToAnchor(view.heightAnchor, multiplier: 0.5).active = true
}
}
Note that we use addArrangedSubview: not addSubview: when adding views to the stack view.
(I've written blogposts about UIStackView as well as others about Auto Layout in general that might help too.)

Setting tableView header's height in Swift

I am trying to set the height of a view that is on top of my prototype cell in a table view controller. I use IB to set it's height (size inspector) and set it to 61 like so (the green view is the 'header' view):
But whenever I run the app, its' height ends up being 568.0. I have an IBOutlet called testUIView for the view in my table view controller, and I do: println("testUIView Height->\(testUIView.frame.height)") and indeed ends up being 568.0 at runtime.
Here is a screenshot showing its' height at runtime:
So my question is: How can I set the view's height so it is 61 at runtime so it indeed looks like my first screenshot (size-wise)?
I tried to set its' height property inside override func viewWillLayoutSubviews() but it did not let me assign a value to the height testUIView.frame.height = CGFloat(61.0).
Any help is appreciated! Thanks in advance!
Cheers!
Here is a solution which uses section header views rather than the actual table header view:
If you'd like to use a header for you UITableView instead you can design another prototype cell in Interface Builder, make a custom class based on a UITableViewCell and assign it to the prototype cell in interface builder on the class inspector.
Then in your controller you're going to use
func tableView(tableView: UITableView, viewForHeaderInSection section: Int) -> UIView?
In that function you're actually going to create a reusable cell from your table view but cast as the custom cell you made for the header. You will have access to all of it's properties like a regular UITableViewCell, then you're just going to return the cell's view
return cell.contentView
Another method you're going to use is
func tableView(tableView: UITableView, heightForHeaderInSection section: Int) -> CGFloat {
return 61.0
}
That one is pretty self explanatory.
Swift 3.0.1
public override func tableView(_ tableView: UITableView, heightForHeaderInSection section: Int) -> CGFloat {
return 61.0
}
Swift 3/Xcode 8:
Add this in viewDidLoad():
let HEADER_HEIGHT = 100
tableView.tableHeaderView?.frame.size = CGSize(width: tableView.frame.width, height: CGFloat(HEADER_HEIGHT))
Enjoy!
The accepted answer doesn't actually answer the question. It instead offers an alternative by using the SECTION header. This question has been answered by others but I will duplicate the answer here with a few more instructions.
Loading the view
Table views are as old as iPhones and therefore you sometimes have to force it to do what you want.
First we need to load the header and manually set its height. Otherwise the view will take more height than it needs. We do this on the viewDidLayoutSubviews callback:
lazy var profileHeaderView: ProfileHeaderView = {
let headerView = ProfileHeaderView()
return headerView
}()
override func viewDidLayoutSubviews() {
super.viewDidLayoutSubviews()
sizeHeaderToFit()
}
private func sizeHeaderToFit() {
profileHeaderView.setNeedsLayout()
profileHeaderView.layoutIfNeeded()
var frame = profileHeaderView.frame
frame.size.height = profileHeaderView.calculateHeight()
profileHeaderView.frame = frame
tableView.tableHeaderView = profileHeaderView
}
As you can see, I like to put my views inside lazy vars. This ensures that they are always created but only when I start using them.
You can also see that I'm calculating the height. In some cases, your height is fixed and therefore you can just set the frame height to a hardcoded value.
Set some priorities
We will likely see some constraint warnings appear in our debugger. This happens because the table view first forces a 0x0 size before using the size we specified above At this moment, your constraints and the height of the view are in conflict with each other.
To clear these, we simply set the constraint priorities. First you should wrap your header view components inside another view (I generally always do this for header views). This will make managing constraints much easier on your header view.
We then need to set the bottom constraint priorities to high:
containerView.setContentCompressionResistancePriority(.defaultHigh, for: .vertical)
containerView.setContentHuggingPriority(.defaultHigh, for: .vertical)
Here is a more complete example:
WARNING: Thought it is still useful as a guide for laying out your views, do not use this code if you're creating your views using nibs or storyboards.
class ProfileHeaderView: UIView {
lazy var containerView: UIView = {
let view = UIView()
return view
}()
override init(frame: CGRect) {
super.init(frame: frame)
setupLayout()
}
required init?(coder aDecoder: NSCoder) {
// We do this because the view is not created using storyboards or nibs.
fatalError("init(coder:) has not been implemented")
}
private func setupLayout() {
self.addSubview(containerView)
containerView.translatesAutoresizingMaskIntoConstraints = false
containerView.topAnchor.constraint(equalTo: self.topAnchor).isActive = true
containerView.leadingAnchor.constraint(equalTo: self.leadingAnchor).isActive = true
containerView.trailingAnchor.constraint(equalTo: self.trailingAnchor).isActive = true
containerView.bottomAnchor.constraint(equalTo: self.bottomAnchor).isActive = true
containerView.setContentCompressionResistancePriority(.defaultHigh, for: .vertical)
containerView.setContentHuggingPriority(.defaultHigh, for: .vertical)
// Set the rest of your constraints against your containerView not self and add your subviews to your containerView not self
}
}
Here is the example of the constraints set using snap-kit:
containerView.snp.makeConstraints() { make in
make.top.equalTo(self.snp.top)
make.leading.equalTo(self.snp.leading)
make.trailing.equalTo(self.snp.trailing)
make.bottom.equalTo(self.snp.bottom).priority(.high)
}
Make sure you add your constraints to the containerView not self and use containerView to add your subviews and rest of your constraints.
It has to be one of the strangest issues in iOS.
If you do just want a fixed height, as of 2019 you can:
public override func viewDidLayoutSubviews() {
var frame = tableView.tableHeaderView!.frame
frame.size.height = 68
tableView.tableHeaderView!.frame = frame
}
Strange stuff.
In swift 4.1 and Xcode 9.4.1
func tableView(_ tableView: UITableView, heightForHeaderInSection section: Int) -> CGFloat {
if UI_USER_INTERFACE_IDIOM() == UIUserInterfaceIdiom.pad {
return 75.0
} else {
return 50.0
}
}
If you use .xib file with UIVIew for your HeaderView, you can use self-sizing header like this
override func layoutSubviews() {
super.layoutSubviews()
// Manually set the view's frame based on layout constraints.
// The parent UITableView uses the header view's frame height when laying out it's subviews.
// Only the header view's height is respected.
// The UITableView ignores the view frame's width.
// Documentation: https://developer.apple.com/documentation/uikit/uitableview/1614904-tableheaderview
frame.size = systemLayoutSizeFitting(
.init(
width: frame.size.width,
height: 0
),
withHorizontalFittingPriority: .required,
verticalFittingPriority: .fittingSizeLevel
)
}

UITableViewWrapperView and UITableView size differs with autolayout

I am building a chat. Everything seem to be quite ok but I bumped into sort of 'buggy' problem.
i got UIViewController with UITextView bar for entering message and UITableView.
They are in this constraint: "V:|-(64)-[chatTable][sendMessageBar]-(keyboard)-|".
When the keyboard is not out - the constant of this constraint is 0. and after keyboard is out - i increase the constant to keyboard height.
when the keyboard is not out:
self.table.contentSize = (375.0,78.5)
self.table.bounds = (0.0,-490.0,375.0,568.5)
self.table.frame = (0.0,64.0,375.0,568.5)
self.table.subviews[0].frame (UITableViewWrapperView) = (0.0,0.0,375.0,568.5)
self.table.subviews[0].frame (UITableViewWrapperView) = (0.0,0.0,375.0,568.5)
and when the keyboard comes out:
self.table.contentSize = (375.0,78.5)
self.table.bounds = (0.0,-274.0,375.0,352.5
self.table.frame = (0.0,64.0,375.0,352.5)
self.table.subviews[0].frame (UITableViewWrapperView) = (0.0,-137.5,375.0,137.5)
self.table.subviews[0].frame (UITableViewWrapperView) = (0.0,0.0,375.0,137.5)
So the UITableViewWrapperView, after I increase constraints constant, differs in size to its superview - UITableView. Is there a way to fix this ? I would assume that UITableViewWrapperView would change its frame and bounds according to UITableView but it does not.
Any ideas where is the problem or how could I work around it ?
ADDING:
After some more research - it seems that it happens somewhere between viewWillLayoutSubviews and viewDidLayoutSubviews. It is kinda weird tho:
override func viewWillLayoutSubviews() {
println("WrapperView Frame :991: \(self.table.subviews[0].frame)") \\ WrapperView Frame :991: (0.0,0.0,375.0,568.5)
super.viewWillLayoutSubviews()
println("WrapperView Frame :992: \(self.table.subviews[0].frame)") \\ WrapperView Frame :992: (0.0,0.0,375.0,568.5)
}
override func viewDidLayoutSubviews() {
println("WrapperView Frame :6: \(self.table.subviews[0].frame)") \\ WrapperView Frame :6: (0.0,-137.5,375.0,137.5)
super.viewDidLayoutSubviews()
println(">> viewDidLayoutSubviews")
}
So it seems that something happens there that messes up the UITableViewWrapperView
The following fixed it for me:
func fixTableViewInsets() {
let zContentInsets = UIEdgeInsetsZero
tableView.contentInset = zContentInsets
tableView.scrollIndicatorInsets = zContentInsets
}
override func viewWillLayoutSubviews() {
super.viewWillLayoutSubviews()
fixTableViewInsets()
}
I discovered that at viewWillAppear() that the insets were all 0. But at viewDidAppear(), they had been modified to apparently offset for navigation bar, etc. This makes the UITableViewWrapperView different from the UITableView.
I changed the insets in its own routine so that it was easier to experiment with calling it from different places. The viewWillLayoutSubviews() let it get changed before being presented - placing the change in viewDidAppear() caused the table to jerk.
I ran into this today and while the fix suggested by #anorskdev works nicely, it seems that the root cause of the issue is the automaticallyAdjustsScrollViewInsets property of UIViewController, which is true by default. I turned it off in my storyboard and the problem went away. Look for the "Adjust Scroll View Insets" checkbox in the View Controller inspector and make sure it's unchecked.
It seems that it is a bug (fighting with this bug took all day for me)
Finally this workaround helped:
for (UIView *subview in tableView.subviews)
{
if ([NSStringFromClass([subview class]) isEqualToString:#"UITableViewWrapperView"])
{
subview.frame = CGRectMake(0, 0, tableView.bounds.size.width, tableView.bounds.size.height);
}
}
After small investigation I have found this solution with setting all the safeAreaInsets and layoutMargins on the UITableView to zero:
Swift 4 snipset:
class CustomTableView: UITableView {
override var safeAreaInsets: UIEdgeInsets {
get {
return .zero
}
}
override var layoutMargins: UIEdgeInsets {
get {
return .zero
}
set {
super.layoutMargins = .zero
}
}
}
The main problem is safeAreaInsets introduced in tvOS 11.0 - the UITableViewWrapperView just took the properties from the parent view (UITableView) and renders the content with safeAreaInsets.
I was facing the same issue on tvOS 11.3, and neither of suggestions related with zero insets or scroll disable did the job, except looping through tableView's subviews and setting the UITableViewWrapperView's frame to the tableView's frame.
override func viewDidAppear(_ animated: Bool) {
super.viewDidAppear(animated)
for view in tableView.subviews {
if String(describing: type(of: view)) == "UITableViewWrapperView" {
view.frame = CGRect(x: 0, y: 0, width: tableView.bounds.size.width, height: tableView.bounds.size.height)
}
}
}
In iOS 11 UITableViewWrapperView has gone, so this problem may occur only on later iOS versions. I faced it on iOS10 when I pushed custom UIViewController in UINavigationController stack.
So, the solution is to override property automaticallyAdjustsScrollViewInsets in custom view controller like this:
override var automaticallyAdjustsScrollViewInsets: Bool {
get {
return false
}
set {
}
}
Objective C version of this answer given by anorskdev
- (void) viewWillLayoutSubviews {
[super viewWillLayoutSubviews];
[tableView setContentInset:UIEdgeInsetsZero];
[tableView setScrollIndicatorInsets:UIEdgeInsetsZero];
}
edit: Turning off automaticallyAdjustsScrollViewInsets on the hosting ViewController, as suggested by Steve Roy in this answer, also worked and is the one I went with, as it seems cleaner to disable the behaviour rather than correcting it afterwards.

Why does UICollectionView log an error when the cells are fullscreen?

I have a UICollectionViewController using a UICollectionViewFlowLayout where my itemSize is the size of the UICollectionView. Basically, this is a line layout of cells where each cell is fullscreen and scrolls horizontally.
In my UICollectionViewFlowLayout subclass, I have overridden prepareLayout as follows:
- (void)prepareLayout {
self.itemSize = self.collectionView.frame.size;
self.scrollDirection = UICollectionViewScrollDirectionHorizontal;
self.collectionView.pagingEnabled = YES;
self.minimumLineSpacing = 0.0;
self.minimumInteritemSpacing = 0.0;
self.sectionInset = UIEdgeInsetsZero;
self.footerReferenceSize = CGSizeZero;
self.headerReferenceSize = CGSizeZero;
}
The UICollectionViewController is very basic returning 10 items in one section. I've included a sample project on GitHub for more detail.
Everything appears to be set up correctly. It looks right in the simulator and on the device but, when the collection view is displayed, there is an error logged to the console:
the behavior of the UICollectionViewFlowLayout is not defined because:
the item height must be less that the height of the UICollectionView minus the section insets top and bottom values.
Note also that the collection view controller in my example is in a navigation controller and while that doesn't look particularly necessary in the example, in my real-world case I need the collection view in a navigation controller.
There is a property on UIViewController–automaticallyAdjustsScrollViewInsets–that defaults to YES. This means that when a UIViewController has a UIScrollView in its view hierarchy–which is true of a UICollectionViewController–the contentInset property of that scroll view is adjusted automatically to account for screen areas consumed by the status bar, navigation bar, and toolbar or tab bar.
The documentation for that property states:
automaticallyAdjustsScrollViewInsets
Specifies whether or not the view controller should automatically adjust its scroll view insets.
#property(nonatomic, assign) BOOL automaticallyAdjustsScrollViewInsets
Discussion
Default value is YES, which allows the view controller to adjust its scroll view insets in response to the screen areas consumed by the status bar, navigation bar, and toolbar or tab bar. Set to NO if you want to manage scroll view inset adjustments yourself, such as
when there is more than one scroll view in the view hierarchy.
The solution is to set automaticallyAdjustsScrollViewInsets to NO somewhere in your UICollectionViewController subclass, such as in viewDidLoad:
- (void)viewDidLoad {
[super viewDidLoad];
self.automaticallyAdjustsScrollViewInsets = NO;
}
I have put an example project on GitHub that illustrates this problem and solution. There are two branches: with_error and fixed_error. Here is a diff of the change on GitHub.
iOS 11 update: automaticallyAdjustsScrollViewInsets is deprecated in iOS 11.0.
Apple recommends using UIScrollView's contentInsetAdjustmentBehavior method instead. I set this value to .never and the error has gone. You can also set this property in Interface Builder.
collectionView.contentInsetAdjustmentBehavior = .never
This issue just occured to me on 3x screens (namely the iPhone 6 Plus.) As it turned out, the autolayout engine did not really like infinite floating point values (such as .33333333), so my solution was to floor the return height in sizeForItemAt:indexPath:.
return CGSize(width: preferredWidth, height: floor(preferredHeight))
I encountered this problem when rotating the device from portrait to landscape, back to portrait. You want to invalidate the collectionView's layout upon device rotation and before the call to super, like so:
- (void)viewWillTransitionToSize:(CGSize)size withTransitionCoordinator:(id<UIViewControllerTransitionCoordinator>)coordinator {
// Causes collection view cells to be resized upon orientation change.
// Important that this is called *before* call to super in order to prevent error from being logged to console.
[self.collectionView.collectionViewLayout invalidateLayout];
[super viewWillTransitionToSize:size withTransitionCoordinator:coordinator];
//...
}
This way had worked for me perfectly!.
I just subtracted the top and bottom insets from the view's height as said in that error.
func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, sizeForItemAt indexPath: IndexPath) -> CGSize {
return CGSize(width: view.frame.width , height: view.frame.height - (view.safeAreaInsets.top + view.safeAreaInsets.bottom))
}
I hope it helps!
If you have collectionView inside scrollView just put .invalidateLayout method inside viewDidLayoutSubviews as shown below:
override func viewDidLayoutSubviews() {
super.viewDidLayoutSubviews()
collectionView.collectionViewLayout.invalidateLayout()
}
I found out that .invalidateLayout method inside viewWillTransitionToSize doesn't change collection view bounds on orientation change in some cases.
A fix that worked for me.
collectionViewLayout.estimatedItemSize = .zero
or do it via IB:
Estimated Size: None
If you create the collection view in the IB, the Estimated Size property (estimatedItemSize) is set to Auto. The docs say it's .zero by default but it's not.
Like Stunner, I had the same problem when rotating from landscape (picture using full width) to portrait mode. His suggestion was the only one which really helped.
Attached the code with latest Swift for his ObjC example ... and as a bonus, my code to find the center cell of the collection view. Works quite nice ;-)
/**
-----------------------------------------------------------------------------------------------
viewWillTransition()
-----------------------------------------------------------------------------------------------
*/
override func viewWillTransition(to size: CGSize, with coordinator: UIViewControllerTransitionCoordinator) {
// find cell in the center of the screen and store it in a global variable
let center = self.view.convert((self.collectionView!.center), to: self.collectionView)
// get the indexPath for the cell in the center of the current screen
if let index = collectionView!.indexPathForItem(at: center) {
// store it in a class property
self.indexPathOfCenterCell = index
}
// force recalculation of margins, borders, cell sizes etc.
self.collectionView?.collectionViewLayout.invalidateLayout()
// inform UIKit about it
super.viewWillTransition(to: size, with: coordinator)
}
ios 10: topmost view was not connected to the view outlet
In my case I had property
layout.estimatedItemSize = UICollectionViewFlowLayout.automaticSize
set in my flow layout. So I had to switch it to some obviously wrong constant (but with some explicit height) to suppress this warning.
UICollectionView is such a thing-in-itself and sometimes absolutely unpredictable
I had similar issue.
After load cell which is full width and some height of screen. on some condition I changed the height of cell then I was getting the same error
to fix this
I used
func updateHeightPerRatio(with image:UIImage) {
let ratio = collectionView.bounds.width / image.size.width
constHeightCollectionView .constant = ceil(image.size.height * ratio)
collectionView.reloadData()
collectionView.performBatchUpdates({
collectionView.layoutIfNeeded()
}) { (completed) in
self.collectionView.reloadData()
self.layoutIfNeeded()
}
}
Solution is reload data then perform batchupdate with that collection view re -calculate the frames . after that reload collectionview again it will apply calculated frames to cell
And now there is no log for issue now.
Hope it is helpful
I was getting the same error when I was trying to embed a UICollectionView in a UITableView. I was generating a new UICollectionView in each UITableView cell, but I did not put any constraints on the height of that UICollectionView. So, when I put a constraint on the height, that error is gone!
In my case I have to reduce bottom inset (from 20 to 0) of cell as I have reduced 20 from height of collectionview
From
func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, insetForSectionAt section: Int) -> UIEdgeInsets {
- return UIEdgeInsets(top: 10, left: 10, bottom: 20, right: 10)
+ return UIEdgeInsets(top: 10, left: 10, bottom: 0, right: 10)
}
func collectionView(_ collectionView: UICollectionView,
layout collectionViewLayout: UICollectionViewLayout,
sizeForItemAt indexPath: IndexPath) -> CGSize {
let size = CGSize(width: 350, height: collectionView.bounds.size.height - 20)
return size
}

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