I've recently tested my app in iOS 11 and for some reason I'm not able to select one of the first 12 rows in a dynamically populated table view. The didSelectRow isn't even triggered for these rows. The other rows work fine, but even when scrolling down and back up (the cells should have been re-used again by then) the first 12 rows don't work.
Even on a static table view all cells that appear on screen when switching to that view controller will not respond, neither will controls inside them, even when they are in different sections. Cells that are out of screen initially again work fine.
I'll be trying to test this in an app with boilerplate code, but is this a known bug? I couldn't find anything online about it.
I've tested this after updating the devices to iOS 11, then again from Xcode 9 beta 6 without changes to the code, and again after migrating to Swift 4. Same behaviour inside the simulator. Up to iOS 10 everything is fine, only with iOS 11 the problem occurs.
This will break my app for users in two weeks, I need to fix it, so any help or advice very much appreciated!
UPDATE: As Paulw11 suggested, there is indeed another view blocking the rows. This was notable as row 12 could only be selected in the lower part of the cell, but not in the upper part.
The cause for this issue is the following code:
extension UIViewController {
func setBackgroundImage(forTableView tableView: UITableView) {
let bgImage = UIImage(named: "Background Image.png")
let bgImageView = UIImageView(image: bgImage)
tableView.backgroundView = bgImageView
let rect = bgImageView.bounds
let effect = UIBlurEffect(style: UIBlurEffectStyle.dark)
let blurView = UIVisualEffectView(effect: effect)
let height: CGFloat
switch screenSize.height {
case 480, 568: height = 455
case 736: height = 623
default: height = 554
}
blurView.frame = CGRect(x: 0, y: 0, width: rect.width, height: height)
let container = UIView(frame: rect)
bgImageView.addSubview(blurView)
let bgOverlay = UIImage(named: "Background Overlay.png")
let bgOverlayImageView = UIImageView(image: bgOverlay)
bgOverlayImageView.alpha = 0.15
bgImageView.addSubview(bgOverlayImageView)
self.view.insertSubview(container, at: 1)
}
}
Somehow since iOS 11 this background image seems to be rendered in front of the cells. Not inserting the container view into the table view's view will solve the issue. I've tried setting the zPosition of the container's layer but it does not help. How can I move the background image behind the cells again.
It's weird that this behaviour would change from iOS 10 to 11...
UPDATE 2: Inserting the container at index -1 fixes the issue:
self.view.insertSubview(container, at: -1)
I don't get why this works, though, shouldn't this index be out of range?
UPDATE 3: As Paulw11 pointed out below, the container is completely useless, it was left over from testing and removing it fixes the issue.
The container view seems to be appearing in front of the other views and preventing touches from making it through to the table view.
As an aside, I would see if you can refactor this to use constraints; It always worries me when you see hard-coded screen sizes, as that may break when new devices are released.
Related
I have screen with two large UICollectionViewCells. Using XIB as Interface Builder. UICollectionView DataSource and Delegate is connected to my UIViewController that contains it.
Installed checkmark is true. isHidden is false. Alpha 1 for cells and UICollectionView. Also I've registered cells for UICollectionView with correct identifiers.
Before I've updated my project from minimum deployment target iOS 13 - UICollectionView works fine. After upgrading to iOS 14 minimum deployment - UICollectionView doesn't show cells. If I return minimum deployment to iOS 13 without any codebase changes - works fine.
Please anyone safe my time as I've wasted whole day already with no luck! Thanks in advance!
So I found the reason of this very strange bug. My goal was to create UICollectionView with cell which contain flexible UITextField. While user is writing - cell changes its size regarding to text height in text field.
To implement it I was using these configurations for my UICollectionView:
Image with UICollectionView configurations
Here You can see that "Cell Size" width is 0, and "Estimate Size" is automatic. It is configured for flexible cell height.
To make it work I have added this code also:
override func viewDidLayoutSubviews() {
super.viewDidLayoutSubviews()
guard let flowLayout = collectionView.collectionViewLayout as? UICollectionViewFlowLayout,
flowLayout.estimatedItemSize.width == .greatestFiniteMagnitude else {
return
}
flowLayout.estimatedItemSize = CGSize(
width: view.frame.width - Size.verticalCollectionInsetsDistance * 2,
// Make the height a reasonable estimate to
// ensure the scroll bar remains smooth
height: 200
)
}
And here is a trick:
When I had upgraded my app to iOS 14 minimum deployment this code is broken. Because, for some reason, when You set "Cell Size" width to 0 and you have iOS 13 minimum deployment, then estimatedItemSize.width == .greatestFiniteMagnitude is true. But for iOS 14 estimatedItemSize.width == .greatestFiniteMagnitude is false and estimatedItemSize.width == 0 is true instead. So now I've fixed my code by adding this condition "flowLayout.estimatedItemSize.width == 0". And here is final version:
override func viewDidLayoutSubviews() {
super.viewDidLayoutSubviews()
guard let flowLayout = collectionView.collectionViewLayout as? UICollectionViewFlowLayout,
flowLayout.estimatedItemSize.width == .greatestFiniteMagnitude || flowLayout.estimatedItemSize.width == 0 else {
return
}
flowLayout.estimatedItemSize = CGSize(
width: view.frame.width - Size.verticalCollectionInsetsDistance * 2,
// Make the height a reasonable estimate to
// ensure the scroll bar remains smooth
height: 200
)
}
P.S. I still don't understand why iOS 14 estimatedItemSize.width is different then iOS 13. If You know answer please describe it in comments. Thanks in advance!
I've got some square buttons that I'd like to add rounded corners to that are proportional to the button's height. In past versions of my app, I had implemented this feature without issues using viewDidLayoutSubviews(). For some reason, after pushing a new version of my app with other features I had tweaked, this section of code no longer functions as expected. Here is the code:
override func viewDidLayoutSubviews() {
for button in buttons {
button!.layer.shadowColor = UIColor.black.cgColor
button!.layer.shadowOffset = CGSize(width: 0, height: 1.0)
button!.layer.shadowOpacity = 0.4
button!.layer.shadowRadius = button!.frame.height / 40
button!.layer.cornerRadius = button!.frame.height / 10
}
Again, this block of code used to work just fine but for some reason it no longer works. What I am experiencing is much larger relative radii on smaller buttons (iPhone SE) compared to bigger buttons (iPads).
To troubleshoot, in viewDidLayoutSubviews(), I'm printing the button!.frame.height and I'm noticing that no matter what device I use the frame height is 395.5, which I believe is the correct size only on the 12.9" iPad. Therefore, the buttons look correct on the 12.9" iPad but the radii end up being too large on all of the smaller devices.
Any idea what's going on here? Why is it that they're all returning the same frame height even though they're visually very different sizes on the different devices?
I copy and pasted the above code into the viewWillAppear() method and
the problem was resolved. I then deleted the code from
viewWillAppear(), leaving me with my original code during posting of
question, and it is continuing to run as expected (working). What
could possibly be the cause of this intermittent behavior
The reason when you initialized the buttons in viewWillAppear and remove them but it still work because your button's frame did not change in the viewDidLayoutSubview method. And the viewDidLayoutSubview is invoked only controller's view is updated, rotated, or changed, which in your case it does not.
If you try to rotate your device you will see your parent view's frame changed.
For more information about view hierarchy. See this article
Try like this:-
override func viewDidLayoutSubviews() {
super.viewDidLayoutSubviews()
for button in buttons {
button!.layer.shadowColor = UIColor.black.cgColor
button!.layer.shadowOffset = CGSize(width: 0, height: 1.0)
button!.layer.shadowOpacity = 0.4
button!.layer.shadowRadius = button!.frame.height / 40
button!.layer.cornerRadius = button!.frame.height / 10
}
The image below shows Xcode graphical debug hierarchy for a UIViewController. It looks like I need to destroy additional data from UITextViews that are being recreated after editing in an array of UITextViews. Each time I make a change, I've set the array of UITextViews to [], then recreate it with the updated data. Even though I verify that the UITextView array is indeed being reset to zero elements, then recreated with the expected number of elements, these ghost images linger on screen and the debug hierarchy shows something isn't being removed.
I suspect there's some sort of housekeeping I need to do to find & destroy additional data related to the UITextViews, and that setting the array back to zero isn't clearing everything out of my subview, but I'm unsure what this might be. I'm hopeful that my mistake seems obvious to those with more experience & you'll point me in the right direction.
I also share some code below, but I suspect the visual may be the most direct clue for the experienced to set me straight.
var topOfViewFrame: CGFloat = 0
textViewArray = []
for textBlock in textBlocks.textBlocksArray { // a textBlock has formatting data for a UITextView
let textBlockHeight = CGFloat(textBlock.numberOfLines) * textBlock.blockFontSize
let viewFrame = CGRect(x: 0, y: topOfViewFrame, width: textBoxWidth, height: textBlockHeight)
var newTextView = UITextView(frame: viewFrame)
newTextView.center = CGPoint(x: screenView.frame.width/2, y: topOfViewFrame + (textBlockHeight/2)) // screenView is the 320x240 subView holding the [UITextViews]
let viewFont = UIFont(name: "AvenirNextCondensed-Medium", size: textBlock.blockFontSize)
newTextView.font = viewFont
newTextView.text = textBlock.blockText
newTextView = configureTextBlockView(textBoxView: newTextView, textBlock: textBlock)
textViewArray.append(newTextView)
screenView.addSubview(newTextView) // screenView is the subview holding the [UITextViews]
topOfViewFrame += newTextView.frame.height // put the next UITextView directly below the previous one
}
Thanks!
If you want to remove all textViews from 'screenView' its not enough just to clear the array.
You need to remove it from superview:
screenView.subviews.forEach({ $0.removeFromSuperview() })
I have recently inherited an an iOS app made in Swift 3.0 from a developer that no longer works here.
The app is made in Xcode and uses storyboards for some of the screens, but not all of them.
On a iPad in landscape orientation the main screen contains an image taking op 2/3 of the width, with a text column next to it taking up 1/3 of the screen. Below are three images each up 1/3 wide. On smaller screens all these items take up 100% of the available width and are displayed underneath each other as a long list.
This is done using the following code in MainController.swift:
override func viewWillLayoutSubviews() {
super.viewWillLayoutSubviews();
// On small screens, columnify the layout
let mainContent = view.viewWithTag(1) as! UIStackView; //contains large image and text
let thumbnails = view.viewWithTag(3) as! UIStackView; //three images
mainContent.axis = .horizontal
mainContent.distribution = .fillProportionally
thumbnails.axis = .horizontal
if(self.view.bounds.width < 1000) {
mainContent.axis = .vertical
mainContent.distribution = .equalSpacing
thumbnails.axis = .vertical
} else {
mainContent.axis = .horizontal
mainContent.distribution = .fillProportionally
thumbnails.axis = .horizontal
}
}
This all works well, unless the user performs the following actions:
Start in landscape orientation on iPad. Image is 2/3, text 1/3
Tap on thumbnail and navigate to a different panel.
Rotate iPad to portrait.
Navigate back to first panel.
Observe that all items are places underneath each other, the image is 100%, but text is only 1/3 of the screen, while it should be 100%
Rotate to landscape, text moves next to image.
Rotate to portrait, text now spans 100% (as it should be)
My hunch would be that manually triggering a re-layout after navigating back to the first panel would solve it, but I cannot find code related to the navigation. This seems all handled by some "Apple magic?". There is probably a way to hook into it, but without any code I don't have any pointers. My only other solution would be to try and refactor the entire application with storyboards, but before I start with that, I was hoping on getting some insights here.
I'm a beginner in creating a custom view. I'm trying to create a custom UIView with a scrollview and buttons that will look like this:
I'm adding a view(view with label of page number) inside of scrollView depending on the the number of pages. Is that how it should be?
Currently it looks like this:
My question is how can I center the subviews of scrollview? and next is what's wrong with this code? Why is that I can only see 1 label inside the view? and the other doesn't show up. How can I scroll to the selected page if the page number is not visible already in the scrollview?
Here's my code:
func addPageNumberViewWithCount(count: Int) {
var pageNumberViewX: CGFloat! = 0
let pageNumberViewDistance: CGFloat! = 10
for i in 1...count {
let pageNumberView = UIView(frame: CGRectMake(pageNumberViewX, 0, 30, 30))
pageNumberView.backgroundColor = UIColor.redColor()
pageNumberView.layer.cornerRadius = pageNumberView.frame.height / 2
pageNumberView.layer.masksToBounds = true
pageNumberView.clipsToBounds = true
// add number label
let label = UILabel(frame: CGRectMake(pageNumberViewX, 0, 30, 30))
label.center = pageNumberView.center
label.text = "\(i)"
label.textAlignment = .Center
pageNumberView.addSubview(label)
// update x for next view
pageNumberViewX = pageNumberView.frame.origin.x + pageNumberView.frame.width + pageNumberViewDistance
// add view inside scrollview
scrollView.addSubview(pageNumberView)
if i == count {
scrollView.contentSize = CGSizeMake(pageNumberViewX + pageNumberView.frame.width, 30)
}
}
}
Part of my answer will go to providing a solution to your question,and another part of my answer will go toward strongly suggesting that this not be the method you use to complete your desired tasks.
At this point, AutoLayout and Interface Builder have come a long way. Where they used to be difficult to use because of their inconsistency and unpredictability, they are now highly predictable and consistent as long as you understand the tools and how to use them.
Apple's suggested method for completing this task (which I mostly stand behind) is creating a .xib file (nib) to lay out the base components of the design, and to load the nib into the view or view controller whenever that design should be used. My question for you: have you tried this, or have you determined for some reason that this would be an unsatisfactory solution to your problem? AutoLayout exists to solve these problems not just in allowing you to achieve your desired solution in this one situation but to achieve it in other situations as well, with varying screen sizes and device types.
Now, if you were to simply ignore all of that and continue on your path, there would be a few good ways to handle your problem. One suggested solution I have:
1) Wrap your pageNumberView in another view. Constrain that view to the size of the scrollView. Doing this gives the scrollView content with which to base its scrollable content size, and gives the inner pageNumberView something to compare itself to.
2) Center the pageNumberView horizontally in its container (the new view that we just created).
Doing this, the page numbers should now center themselves in the container until they reach a size where they exceed the width of the scrollView. At that point, they will then continue to expand, making the area horizontally scrollable.
I can provide code examples of how you would do this, but frankly I would much prefer if you scrapped the idea of doing things this way and instead opted for the AutoLayout method at least, and perhaps even the Interface Builder method. I started out with iOS the same way you did, trying to do everything in code. It really isn't the best way to do things, at least with regard to iOS.
Edit: I've provided an example of how this would look in Interface Builder using UINib. I've populated the view with an example of 5 pages to show what it is like. I will see if I can make a GIF or something similar to show what each of the subviews look like.
For the OP, my suggestion would be this: Use this for reference, and go learn the constraints system. It is extremely unlikely that you will find success with iOS if you do not learn and utilize the constraints system. Coding in X values to a UIView's frame is only going to create a product with poor, inconsistent performance across devices, and will take much, much longer than it would to take the time to learn constraints.
Perhaps you should have a UICollectionView with a cell for each of these buttons. That's a better way of doing this, and you can lay it out again when the screen rotates and it changes width.
Those cells will layout offset to the left. You can solve that this way:
let pageNumberViewTotalWidth = 30 * count + (pageNumberViewDistance * count - 1)
self.collectionView.contentInset.left = (self.collectionView.frame.size.width - pageNumberViewTotalWidth) / 2
The labels aren't showing up because you're setting their frame's x to be the same as the page number view's x. It's frame should be relative to it's superview, in this case pageNumberView.
First Question of yours "how can I center the subviews of scrollview?"
Solution: lets suppose you have in total 50 pages and you want to show 5 pages at a time in the scrollview.
Then make 10 subviews of equal widths where each subview width will be equal to visible portion of the collection view that is
self.view.size.width - 2*(width of toggle button)
Then in each container view add 5 of your pageNumberView placed at equal distance
lets pageNumberViewWidth = container.width/5 - 2*margin
now pageNumberView frame will be (margin,0,pageNumberViewWidth,height)
In this way in each container view your pageNumberViews will be placed equally and it will look as if you have centred them.
Second Question "Why is that I can only see 1 label inside the view?"
Answer : Its because you are setting label frame incorrectly
let label = UILabel(frame: CGRectMake(pageNumberViewX, 0, 30, 30))
Here label is the subview of pageNumberView So you have to set its frame according to its parent's view which is pageNumberView, so change it to
let label = UILabel(frame: CGRectMake(0, 0, 30, 30))
First time it was right because pageNumberViewX is 0 for first iteration after that it become some positive value which makes its frame shifted to right but its parent's width is small so its not visible to you.
Third Question : "How can I scroll to the selected page if the page number is not visible already in the scrollview?"
For this you need to find the frame of your selected page:
you can do that by using the offset that you used to create pageNumberView.
(width of each pageNumberView)*pageNumber = starting point of the required pageNumberView.
let frame : CGRect = CGRectMake(calculated offset above, 0,30, 30)
//where you want to scroll
self.scrollView.scrollRectToVisible(frame, animated:true)
I hope this will help you in solving your problem
Edit for first problem
func addPageNumberViewWithCount(count: Int) {
var containerViewX: CGFloat! = 0
let pageNumberViewDistance: CGFloat! = 10
let pageNumberViewPerSubview = 5
var numberOfSubview = count/pageNumberViewPerSubview
if(count % pageNumberViewPerSubview > 0){
numberOfSubview = numberOfSubview + 1
}
var pagesLeft = count
for i in 1...numberOfSubview {
var pageNumberViewX: CGFloat! = 0
let containerView : UIView = UIView(frame:CGRectMake(containerViewX,0,scrollView.frame.size.width,scrollView.frame.size.height))
if(pagesLeft < pageNumberViewPerSubview){
for k in 1...pagesLeft{
}
}
else{
for j in 1...pageNumberViewPerSubview{
let pageNumberView = UIView(frame: CGRectMake(pageNumberViewX, 0, 30, 30))
pageNumberView.backgroundColor = UIColor.redColor()
pageNumberView.layer.cornerRadius = pageNumberView.frame.height / 2
pageNumberView.layer.masksToBounds = true
pageNumberView.clipsToBounds = true
// add number label
let label = UILabel(frame: CGRectMake(0, 0, 30, 30))
label.text = "\(i)"
label.textAlignment = .Center
pageNumberView.addSubview(label)
// update x for next view
pageNumberViewX = pageNumberView.frame.origin.x + pageNumberView.frame.width + pageNumberViewDistance
containerView.addSubview(pageNumberView)
}
containerViewX = containerViewX + scrollView.frame.size.width
// add view inside scrollview
scrollView.addSubview(containerView)
pagesLeft = pagesLeft - pageNumberViewPerSubview
}
if i == count {
scrollView.contentSize = CGSizeMake(numberOfSubview*scrollView.frame.size.width, 30)
}
}
}