Looping through subviews swift / ios - ios

var replycount = replies.count
var startingTag = 10
for subview in self.personView.subviews {
if replycount > 0 {
subview.viewWithTag(startingTag)?.backgroundColor = .green
replycount = replycount - 1
startingTag = startingTag + 1
}
}
}
I'm pulling a number from a server (replycount) and trying to represent the number by coloring some views on the screen. I've got 10 bubbles across the bottom, and if replycount was 4, starting from the left I'd want 4 of the bubbles to have a green background color, and the rest to remain their default black.
What I'm trying to do with the above code is to grab the reply count which I"m doing successfully, my first bubble starts at a tag of 10 and goes up to 19, and if the reply count is more than 0, meaning there is a reply, I'm wanting to take the first tag of 10, make it green, then move on to the next tag of 11, minus from the reply count, and keep going until there are no more replies.
The only time the code below works is if I comment out
replycount = replycount - 1
and change viewWithTag(startingTag) to viewWithTag(10) and hardcode in the number. If either of those two things aren't done the view's color is not changed.
Is there a better way to do this, or any ideas why I'm running into this issue?

Skip looping through subviews and just do self.view.viewWithTag? Although I'm just assuming all of the bubbles are in the same view, and not each in a different subview.
Although I would probably have written it something like this for clarity:
var replycount = replies.count
for tag in 10 ..< (10 + replycount) {
self.view.viewWithTag(tag)?.backgroundColor = .green
}

Related

Why does slides[i].frame print a different value than SlideScrollView.subviews[i].frame

I was trying to calculate the current visible "Slide" in my UIScrollView when I noticed this. I couldn't figure out why I am getting these values. Especially frame 2 & 3 show strange values.
can anyone tell me if and where I am wrong and how do I get the bottom values to match that of the top?
Here is my code :
{...}
for i in 0 ..< slides.count
{
slides[i].frame = CGRect(x:CONSTwid * CGFloat(i),y:0,width:CONSTwid+20,height : view.frame.height)
print("slide \(i) frame : \(slides[i].frame)")
SlideScrollView.addSubview(slides[i])
}
let container = CGRect(x: SlideScrollView.contentOffset.x, y: SlideScrollView.contentOffset.y, width: SlideScrollView.frame.size.width, height: SlideScrollView.frame.size.height)
//this was just to see the result (do not ask me to loop it...I know :-P)
print("sr \(container)")
print("srcz\(SlideScrollView.contentSize)")
print("slide 0 frame \(SlideScrollView.subviews[0].frame)")
print("slide 1 frame \(SlideScrollView.subviews[1].frame)")
print("slide 2 frame \(SlideScrollView.subviews[2].frame)")
{...}
here is the output :
Console Output :
Thanks in advance
Since slides is an array of views you wan't to check then that is the array you need to use. Although subviews is opened property it can still hold views you should not be looking into. Basically any view can have any number of subviews for any reason. This may even vary between devices or OS versions.
In your case you seem to have an extra view of size 2.5 x 7 that looks like a very small view. Perhaps a scroll indicator?

Swift 4 reverse change height of a UIView

I would like to build a progressbar. I took a rectangular view (progressBarBckgr) and put another one in front of it (progressBar).
The one in the front should increase its height by tabbing on the correct answer within a quiz app.
func updateUI () {
let numberOfAllQuestions = allQuestion.questionList.count
print(numberOfAllQuestions) //prints 3
let progressBarBckgrHeight = progressBarBckgr.frame.size.height
let progressBarBckgrHeightInt = Int(progressBarBckgrHeight)
let progressBarBckgrHeightPiece = progressBarBckgrHeightInt / numberOfAllQuestions
progressBarOutlet.frame.size.height = (progressBarBckgr.frame.height) + CGFloat (progressBarBckgrHeightPiece)
}
So with every correct clicked answer the progressbar should increase just so far, that in the end of quiz the whole backgroundprogressbar is covered.
Example:
10 Questions
-> clicked answer fills increases the progressbar's height for 1/10
In addition to that i would like to increase the bar from the bottom to the top. As i enter the property height to increase it, it only gets bigger in direction bottom. Is there a nice turnaround trick?
Thanks!!!
You also need to move the view up by the amount of height you have increased (progressBarBckgrHeightPiece)
Also, you should set the frame directly.
progressBarOutlet.frame = CGRect(x: progressBarOutlet.frame.origin.x,
y: progressBarOutlet.frame.origin.y - progressBarBckgrHeightPiece, // Notice here
width: progressBarOutlet.frame.width,
height: progressBarOutlet.frame.height + CGFloat(progressBarBckgrHeightPiece))

Swift UIPageControl not showing dots

I have a UIPageControl which is updated based on a UIScrollView (numberOfPages and currentPage).
It has black and gray colors for current page and other pages dots, respectively.
When loading the app for the first time, only the current page dot shows up, not the gray ones. After scrolling the view, the gray dots appear and everything is fine.
What could be causing this?
Update:
So, I set the UIPageControl to have 3 pages
self.pageControl.numberOfPages = 3
and I set the current page
self.pageControl.currentPage = 0
The page control should present like o x x (o - selected, x - unselected), but it actually shows only the current page: o
Then I did this:
for i in 0..<(self.pageControl.numberOfPages) {
self.pageControl.currentPage = i
}
self.pageControl.currentPage = 0
which solves the problem. Obvisously, it's an hack.
So I wonder if this a bug with the page control or something that I'm doing wrong..
Please provide us more information. As per your short description i can give you below suggestions.
1. Check page control frame.
2. Change your de-select state page dot color. It might be matching with your first page’s background color so that’s why it’s not showing.
The easy solution I found is as below.
// lets set current page from 0 to N number of items
for i in 0..<adsArray.count {
pageControl.currentPage = i
}
// set current page back to 0 as we need
pageControl.currentPage = 0

iOS 11 breaks row selection

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.

How to center the subviews of UIScrollView

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)
}
}
}

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