UILabel is not replacing previous text when view refreshed - swift

I have the following function being called in a ViewController that passes in data to build a list of transactions. Each time the page refreshes, this is called and new data is shown. All is good, except for one remaining frustrating bug: when the new data is loaded the previous balancedOwedAmountLabel.text still shows the previous amount.
So on each refresh, the text is written on top of the previous text each time. This results in a jumbled mess of text each time the page is refreshed. It would be expected to have the previous text removed, and replaced with the new text that I determine.
I've tried manually setting the balancedOwedAmountLabel.text = nil to simply remove it and then reset it each time the data is retrieved and painted, but it won't work. I've also tried removing the subview entirely via balancedOwedAmountLabel.removeFromSuperview() and that doesn't seem to do the trick either.
Since I'm not using a Storyboard I can't connect IBOutlets so I'm having to resort to figuring out how to get around this problem programmatically. How do I go about solving this with the following code?
private func buildTransactionTableView() {
let stackview = UIStackView()
stackview.axis = .vertical
stackview.distribution = .fill
stackview.spacing = 15
self.view.insertSubview(stackview, belowSubview: (self.accountSummaryTableViewController?.view)!)
stackview.translatesAutoresizingMaskIntoConstraints = false
stackview.topAnchor.constraint(equalTo: self.transactionsTableView.bottomAnchor, constant: 0).isActive = true
stackview.leadingAnchor.constraint(equalTo: view.safeAreaLayoutGuide.leadingAnchor, constant: 10).isActive = true
stackview.trailingAnchor.constraint(equalTo: view.safeAreaLayoutGuide.trailingAnchor, constant: -10).isActive = true
stackview.bottomAnchor.constraint(equalTo: view.safeAreaLayoutGuide.bottomAnchor,constant: -30).isActive = true
// full width parent SV
let headlineStackView = UIStackView()
headlineStackView.axis = .horizontal
headlineStackView.alignment = .top
headlineStackView.distribution = .fill
let titleLabel = UILabel(frame: CGRect(x:0,y:0,width:200,height:21))
titleLabel.textAlignment = .left
titleLabel.textColor = .black
titleLabel.font = UIFont.boldSystemFont(ofSize: 14.00)
titleLabel.text = "Transaction History"
headlineStackView.addArrangedSubview(titleLabel)
stackview.addArrangedSubview(headlineStackView)
// SV for balance informations
let balanceStackView = UIStackView()
balanceStackView.axis = .horizontal
balanceStackView.distribution = .fill
headlineStackView.addArrangedSubview(balanceStackView)
let balanceOwedLabel = UILabel(frame: CGRect(x: 0, y: 0, width: 200, height: 21))
balanceOwedLabel.textAlignment = .right
balanceOwedLabel.textColor = .black
balanceOwedLabel.font = balanceOwedLabel.font.withSize(14.00)
balanceOwedLabel.text = "Balance Owed"
balanceStackView.addArrangedSubview(balanceOwedLabel)
let balancedOwedAmountLabel = UILabel(frame: CGRect(x: 0, y: 0, width: 200, height: 21))
balancedOwedAmountLabel.textAlignment = .right
balancedOwedAmountLabel.textColor = UIColor(red: 33.00/255, green: 150.00/255, blue: 243.00/255, alpha: 1.00)
balancedOwedAmountLabel.font = UIFont.boldSystemFont(ofSize: 14.00)
var amount = 0.00
for rtp in self.userTransactions! {
if rtp.repaymentDate == nil && rtp.rtpData.amount.value != nil {
let value = Double((rtp.rtpData.amount.value)!)
amount = amount + value!
}
}
balanceStackView.addArrangedSubview(balancedOwedAmountLabel)
// This amount overwrites previous amount on screen when refreshed
// The amount is not being removed and replaced wih this new amount
balancedOwedAmountLabel.text = " $\(String(format: "%.2f", amount))"
let rtpTableVC = UserTransactionsTableViewController(style: .plain)
rtpTableVC.tableView.allowsSelection = false
rtpTableVC.tableView.separatorStyle = .none
rtpTableVC.tableView.isScrollEnabled = true
rtpTableVC.rtpTransactions = self.rtpTransactions
stackview.addArrangedSubview(rtpTableVC.view)
self.userTransactionsTableViewController = rtpTableVC
}
}

It looks like each time this function is called, you create a new stackview and add it in self.view. But I cannot see when you remove previous stackview?
One way of fixing it would be: store reference on current stackview and remove it before adding new one as:
var currentStackView: UIStackView?
private func buildTransactionTableView() {
currentStackView.removeFromSupperView()
let stackview = UIStackView()
currentStackView = stackview
...
}

Related

How to make vertical labels bar in Swift?

I would like to make such layout via swift:
I tried to make it in such way:
var buttonArray = [UILabel]()
for (myKey,myValue) in colorDictionary{
buttonArray += [colorButton(withColor: myValue, title: myKey)]
}
let horizontalStack = UIStackView(arrangedSubviews: buttonArray)
horizontalStack.axis = .horizontal
horizontalStack.distribution = .fillEqually
horizontalStack.alignment = .fill
horizontalStack.translatesAutoresizingMaskIntoConstraints = false
horizontalStack.transform = CGAffineTransform(rotationAngle: -CGFloat.pi / 2)
let label2 = UILabel()
label2.text = "Label"
label2.backgroundColor = .red
label2.textColor = .white
label2.textAlignment = .center
label2.lineBreakMode = .byCharWrapping
label2.numberOfLines = 0
label2.translatesAutoresizingMaskIntoConstraints = false
label2.transform = CGAffineTransform(rotationAngle: -CGFloat.pi / 2)
let mainStackView = UIStackView()
mainStackView.axis = .horizontal
mainStackView.translatesAutoresizingMaskIntoConstraints = false
mainStackView.addArrangedSubview(label2)
mainStackView.addArrangedSubview(horizontalStack)
mainContainer.addSubview(mainStackView)
NSLayoutConstraint.activate([
mainStackView.topAnchor.constraint(equalTo: mainContainer.topAnchor, constant: 5),
mainStackView.leftAnchor.constraint(equalTo: mainContainer.leftAnchor,
constant: 20),
mainStackView.rightAnchor.constraint(equalTo: mainContainer.rightAnchor,
constant: -20),
mainStackView.heightAnchor.constraint(equalToConstant: 270),
])
where colorButton is:
func colorButton(withColor color:UIColor, title:String) -> UILabel{
let newButton = UILabel()
newButton.backgroundColor = color
newButton.text = title
newButton.textAlignment = .center
newButton.textColor = UIColor.white
return newButton
}
and here is the result which I got:
How I can make all these labels look like the desired image? And also I'm not sure whether label rotation can be done by my method.
What I would do is first get it working without any transformations so it appears as a normal, not rotated setup. Once that is working, you only need to apply a single transformation to the main stack view to get the whole thing rotated. Then finally you can tweak the constraints to get it positioned correctly.
Here is code that works:
let horizontalStack = UIStackView(arrangedSubviews: buttonArray)
horizontalStack.axis = .horizontal
horizontalStack.distribution = .fillEqually
horizontalStack.alignment = .fill
horizontalStack.translatesAutoresizingMaskIntoConstraints = false
let label2 = UILabel()
label2.text = "Label"
label2.backgroundColor = .red
label2.textColor = .white
label2.textAlignment = .center
label2.lineBreakMode = .byCharWrapping
label2.numberOfLines = 0
label2.translatesAutoresizingMaskIntoConstraints = false
let mainStackView = UIStackView()
mainStackView.axis = .vertical
mainStackView.distribution = .equalSpacing
mainStackView.translatesAutoresizingMaskIntoConstraints = false
mainStackView.addArrangedSubview(label2)
mainStackView.addArrangedSubview(horizontalStack)
mainStackView.transform = CGAffineTransform(rotationAngle: -CGFloat.pi / 2)
mainContainer.addSubview(mainStackView)
NSLayoutConstraint.activate([
mainStackView.centerYAnchor.constraint(equalTo: mainContainer.centerYAnchor),
mainStackView.centerXAnchor.constraint(equalTo: mainContainer.leftAnchor, constant: 40),
// Set the "width", not the "height"
mainStackView.widthAnchor.constraint(equalToConstant: 270),
])
Changes:
I removed the transformation you had for the horizontal stack view and the big label.
I added a single transformation to the main stack view.
I used a vertical, not horizontal, stack view for the main stack.
Updated the properties of the main stack view so the main label fills the area above the other labels.
Updated the constraints. Adjust those to suit your needs.
Note that you need to set the width of the main stack view since the constraint is relative to the untransformed main stack view.

The UI search bar disappears when clicked( possibly NSLayoutConstraint issue)

A quick question, for what should've been an easy implementation.
Im trying to implement a UISearchcontroller and the UIsearchbar property when trying to customize it and set constraints behaves properly appears perfect but the minute i click on the search bar it resets its constraints to nil(guessing based on visual debugger).
Before clicking
and here is the second image which shows what happens when clicked
After clicking
Ive been trying to do this for a day now.
Context: My Main VC is a collection view and another button.
below is the search view specific code, I tried isolating the issue in a playground file and noticed issue starts when i add constraints to it.
var searchController:UISearchController!
private func setupSearchView(){
let viewController = UISearchController(searchResultsController: nil)
viewController.delegate = self
let bar = viewController.searchBar
bar.delegate = self
bar.searchBarStyle = .minimal
bar.translatesAutoresizingMaskIntoConstraints=false
bar.searchTextField.layer.cornerRadius = 20
bar.searchTextField.textColor = .darkGray
bar.searchTextField.backgroundColor = .white
bar.showsCancelButton = false
bar.layer.shadowColor = UIColor(red: 0, green: 0, blue: 0, alpha: 0.25).cgColor
bar.layer.shadowOffset = CGSize(width: 0.0, height: 2.0)
bar.layer.shadowOpacity = 1.0
bar.layer.shadowRadius = 0.0
bar.layer.masksToBounds = false
guard let customFont = UIFont(name: "Poppins-SemiBold", size: 14.0) else {
fatalError("""
Failed to load the "CustomFont-Light" font.
Make sure the font file is included in the project and the font name is spelled correctly.
"""
)}
bar.searchTextField.font=customFont
self.searchController = viewController
self.view.addSubview(bar)
bar.isHidden = true
}
func setupContstraints() {
//NSLayoutConstrainst
let searchBar:UISearchBar=searchController!.searchBar
NSLayoutConstraint.activate([
searchButton!.trailingAnchor.constraint(equalTo: view.trailingAnchor, constant: -30),
searchButton!.topAnchor.constraint(equalTo: view.topAnchor, constant: 30),
searchButton!.widthAnchor.constraint(equalToConstant: 50),
searchButton!.heightAnchor.constraint(equalToConstant: 50),
//search bar
searchBar.centerXAnchor.constraint(equalTo: self.view.centerXAnchor),
searchBar.topAnchor.constraint(equalTo: self.view.topAnchor, constant: 30),
searchBar.widthAnchor.constraint(equalToConstant: 170.0),
searchBar.heightAnchor.constraint(equalToConstant: 50.0)]
)
Update:
When i gave the search bar fixed width and height(not ideal for different device size) it now appears with the width and height but doesn't obey the top anchor constraint.
See current image
also updated the snippet with current constraints
Give a fixed width and height value for your "SearchBar" object. It will probably be fixed.
It may take up as much width as the cursor when clicked.
Comment out or delete the 2 lines below while giving a fixed height and width for the searchBar.
searchBar.leadingAnchor.constraint(equalTo: self.view.leadingAnchor, constant: 50),
searchBar.trailingAnchor.constraint(equalTo: self.view.trailingAnchor, constant: -100)
Rid of the UISearchController and use a UISearchBar instead.
let searchBar = UISearchBar()
let clearButton = UIButton()
override func viewDidLoad() {
super.viewDidLoad()
view.backgroundColor = .gray
setupSearchView()
}
private func setupSearchView(){
searchBar.searchBarStyle = .minimal
searchBar.translatesAutoresizingMaskIntoConstraints=false
searchBar.searchTextField.layer.cornerRadius = 20
searchBar.searchTextField.textColor = .darkGray
searchBar.searchTextField.backgroundColor = .white
searchBar.showsCancelButton = false
searchBar.layer.shadowColor = UIColor(red: 0, green: 0, blue: 0, alpha: 0.25).cgColor
searchBar.layer.shadowOffset = CGSize(width: 0.0, height: 2.0)
searchBar.layer.shadowOpacity = 1.0
searchBar.layer.shadowRadius = 0.0
searchBar.layer.masksToBounds = false
// guard let customFont = UIFont(name: "Poppins-SemiBold", size: 14.0) else {
// fatalError("""
// Failed to load the "CustomFont-Light" font.
// Make sure the font file is included in the project and the font name is spelled correctly.
// """
// )}
// bar.searchTextField.font=customFont
// set your search clear button
clearButton.setImage(UIImage(systemName: "multiply.circle.fill"), for: .normal)
clearButton.tintColor = .red
let searchStack = UIStackView(arrangedSubviews: [searchBar, clearButton])
searchStack.axis = .horizontal
searchStack.distribution = .fill
searchStack.alignment = .fill
searchStack.spacing = 16
searchStack.translatesAutoresizingMaskIntoConstraints = false
self.view.addSubview(searchStack)
// bar.isHidden = true
NSLayoutConstraint.activate([
clearButton.heightAnchor.constraint(equalTo: clearButton.widthAnchor),
searchStack.topAnchor.constraint(equalTo: view.safeAreaLayoutGuide.topAnchor, constant: 30),
searchStack.leadingAnchor.constraint(equalTo: view.safeAreaLayoutGuide.leadingAnchor, constant: 30),
searchStack.trailingAnchor.constraint(equalTo: view.safeAreaLayoutGuide.trailingAnchor, constant: -30),
searchStack.heightAnchor.constraint(equalToConstant: 50)
])
}

What is wrong with this StackView?

what is wrong with my StackView?
This is the code:
class PushUpViewController: UIViewController {
override func viewDidLoad() {
super.viewDidLoad()
view.backgroundColor = .white
setUpStackView()
}
func setUpStackView() {
// SetUp StackView:
stackView.translatesAutoresizingMaskIntoConstraints = false
stackView.axis = .vertical
stackView.alignment = .center
stackView.distribution = .fillProportionally
stackView.spacing = 50
view.addSubview(stackView)
// SetUp StackView Constraints:
stackView.pin(to: view)
stackView.setCustomSpacing(50, after: PushUpButton)
stackView.setCustomSpacing(100, after: TimeLabel)
// Set Elements to StackView:
stackView.addArrangedSubview(TimeLabel)
stackView.addArrangedSubview(PushUpButton)
stackView.addArrangedSubview(secondStackView)
// SetUp PushUpButton:
PushUpButton.backgroundColor = .white
PushUpButton.setTitle("\(count)", for: .normal)
PushUpButton.setTitleColor(.systemGray, for: .normal)
PushUpButton.titleLabel?.font = UIFont.boldSystemFont(ofSize: 70)
PushUpButton.translatesAutoresizingMaskIntoConstraints = false
PushUpButton.heightAnchor.constraint(equalToConstant: 300).isActive = true
PushUpButton.widthAnchor.constraint(equalToConstant: 150).isActive = true
// SetUp TimeLabel
TimeLabel.textAlignment = .center
TimeLabel.text = "\(counter)"
TimeLabel.textColor = .black
TimeLabel.font = .boldSystemFont(ofSize: 30)
self.view.addSubview(TimeLabel)
TimeLabel.translatesAutoresizingMaskIntoConstraints = false
TimeLabel.widthAnchor.constraint(equalToConstant: 300).isActive = true
TimeLabel.heightAnchor.constraint(equalToConstant: 200).isActive = true
// SetUp SecondStackView
secondStackView.translatesAutoresizingMaskIntoConstraints = false
secondStackView.axis = .horizontal
secondStackView.alignment = .center
secondStackView.distribution = .fillEqually
secondStackView.spacing = 20
// SetUp SecondStackView Constrains
secondStackView.heightAnchor.constraint(equalToConstant: 50).isActive = true
secondStackView.widthAnchor.constraint(equalTo: view.widthAnchor, constant: -15).isActive = true
// Set Elements:
secondStackView.addArrangedSubview(breakButton)
secondStackView.addArrangedSubview(stopbutton)
//SetUp BreakButton
breakButton.backgroundColor = .lightGray
breakButton.setTitle("Break", for: .normal)
breakButton.setTitle("Start", for: .selected)
breakButton.titleLabel?.font = UIFont.boldSystemFont(ofSize: 20)
breakButton.setTitleColor(.white, for: .normal)
breakButton.layer.cornerRadius = 12
breakButton.layer.borderWidth = 1
breakButton.layer.borderColor = UIColor.white.cgColor
// breakButton.addTarget(self, action: #selector(BreakButtonTapped), for: .touchUpInside)
breakButton.translatesAutoresizingMaskIntoConstraints = false
NSLayoutConstraint.activate([
breakButton.widthAnchor.constraint(equalToConstant: 150),
breakButton.heightAnchor.constraint(equalToConstant: 50)
])
// SetUp StopButton:
stopbutton.backgroundColor = .systemRed
stopbutton.setTitle("Stop", for: .normal)
stopbutton.titleLabel?.font = UIFont.boldSystemFont(ofSize: 20)
stopbutton.setTitleColor(.white, for: .normal)
stopbutton.layer.cornerRadius = 12
stopbutton.layer.borderWidth = 1
stopbutton.layer.borderColor = UIColor.white.cgColor
// stopbutton.addTarget(self, action: #selector(stopButtonTapped), for: .touchUpInside)
stopbutton.translatesAutoresizingMaskIntoConstraints = false
NSLayoutConstraint.activate([
stopbutton.widthAnchor.constraint(equalToConstant: 150),
stopbutton.heightAnchor.constraint(equalToConstant: 50)
])
}
}
And this is how it look:
But it should looks like this:
This is what comes in the console when I am on the StackView VC:
I have no idea what this means or what I should do to solve this problem
I do not understand StackViews... I watched a lot of yt tutorials but they are all the same and did't help me. My biggest problem is the distribution of the StackView: I don't know where the difference is
First tip: forget using .fillProportionally with stack views. It is almost never used ... and when it is used, it's used for very specific reasons.
Second tip: during development, give your UI elements contrasting background colors to make it easy to see the frames at run-time.
Third tip: Use leadingLowerCase for variable and function names... Use LeadingUpperCase for class names.
Fourth tip: group similar code together - such as setting view properties, setting constraints, etc - and include logical comments to make it easier to follow what your code is doing.
Take a look at this:
class PushUpViewController: UIViewController {
let stackView = UIStackView()
let secondStackView = UIStackView()
let pushUpButton = UIButton()
let breakButton = UIButton()
let stopbutton = UIButton()
let timeLabel = UILabel()
var count: Int = 0
var counter: Float = 0.0
override func viewDidLoad() {
super.viewDidLoad()
view.backgroundColor = .white
setUpStackView()
}
func setUpStackView() {
// SetUp StackView:
stackView.translatesAutoresizingMaskIntoConstraints = false
stackView.axis = .vertical
stackView.alignment = .fill
stackView.distribution = .fill
// SetUp timeLabel
timeLabel.textAlignment = .center
timeLabel.text = "\(counter)"
timeLabel.textColor = .black
timeLabel.font = .boldSystemFont(ofSize: 30)
// SetUp pushUpButton:
pushUpButton.backgroundColor = .white
pushUpButton.setTitle("\(count)", for: .normal)
pushUpButton.setTitleColor(.systemGray, for: .normal)
pushUpButton.titleLabel?.font = UIFont.boldSystemFont(ofSize: 70)
// SetUp secondStackView
secondStackView.axis = .horizontal
secondStackView.alignment = .fill
secondStackView.distribution = .fillEqually
secondStackView.spacing = 20
//SetUp breakButton
breakButton.backgroundColor = .lightGray
breakButton.setTitle("Break", for: .normal)
breakButton.setTitle("Start", for: .selected)
breakButton.titleLabel?.font = UIFont.boldSystemFont(ofSize: 20)
breakButton.setTitleColor(.white, for: .normal)
breakButton.layer.cornerRadius = 12
breakButton.layer.borderWidth = 1
breakButton.layer.borderColor = UIColor.white.cgColor
// SetUp stopButton:
stopbutton.backgroundColor = .systemRed
stopbutton.setTitle("Stop", for: .normal)
stopbutton.titleLabel?.font = UIFont.boldSystemFont(ofSize: 20)
stopbutton.setTitleColor(.white, for: .normal)
stopbutton.layer.cornerRadius = 12
stopbutton.layer.borderWidth = 1
stopbutton.layer.borderColor = UIColor.white.cgColor
// add buttons to horizontal second stack view
secondStackView.addArrangedSubview(breakButton)
secondStackView.addArrangedSubview(stopbutton)
// if we want the center PushUpButton to be 300 x 150
// and centered vertically
// we need to embed it in a clear view
let holderView = UIView()
// add PushUpButton to holderView
holderView.addSubview(pushUpButton)
// views added as arrangedSubviews of a stack view automatically get
// .translatesAutoresizingMaskIntoConstraints = false
// but, because we're adding the PushUpButton as a subview
// of holderView, we need to set it here
pushUpButton.translatesAutoresizingMaskIntoConstraints = false
// add views to stack view
stackView.addArrangedSubview(timeLabel)
stackView.addArrangedSubview(holderView)
stackView.addArrangedSubview(secondStackView)
// add stackView to view
view.addSubview(stackView)
// SetUp StackView Constraints:
//stackView.pin(to: view)
// respect safe-area
let g = view.safeAreaLayoutGuide
NSLayoutConstraint.activate([
// constrain stackview to full view (safe-area)
// to bottom with Zero extra space
stackView.bottomAnchor.constraint(equalTo: g.bottomAnchor, constant: 0.0),
// to top with 20-pts "padding"
stackView.topAnchor.constraint(equalTo: g.topAnchor, constant: 20.0),
// and 8-pts "padding" on each side
stackView.leadingAnchor.constraint(equalTo: g.leadingAnchor, constant: 8.0),
stackView.trailingAnchor.constraint(equalTo: g.trailingAnchor, constant: -8.0),
// pushUpButton should be 300x150
pushUpButton.widthAnchor.constraint(equalToConstant: 300.0),
pushUpButton.heightAnchor.constraint(equalToConstant: 150.0),
// pushUpButton should be centered in holderView
pushUpButton.centerXAnchor.constraint(equalTo: holderView.centerXAnchor),
pushUpButton.centerYAnchor.constraint(equalTo: holderView.centerYAnchor),
// bottom buttons should have Height: 50
secondStackView.heightAnchor.constraint(equalToConstant: 50.0),
])
// break and stop button actions
//breakButton.addTarget(self, action: #selector(BreakButtonTapped), for: .touchUpInside)
//stopbutton.addTarget(self, action: #selector(stopButtonTapped), for: .touchUpInside)
// during development, so we can see the layout easily
//holderView.backgroundColor = .yellow
//PushUpButton.backgroundColor = .green
//TimeLabel.backgroundColor = .cyan
}
}
Result on iPhone 11:
on iPhone 8:
and with background colors to help during development:
Additional Tip:
When learning auto layout (particularly stack views), work on your layout in Storyboard / Interface Builder. You can immediately see how it looks and what happens when changing values / properties. You can also change the View as: to immediately see how it looks on different devices / screen sizes. If you want to keep everything in code, once you have your layout looking the way you want, then replicate those constraints and settings in code.

Cannot see Buttons in UIScrollView

I was making a list in the form of scrollview in swift where the view consists of various types such as labels, button etc.
However when i added the button to the subview, they were not displayed although all other labels etc were displayed. I also tried messing around in the constraints and anchors.
On the other hand when i added the same button to self.view.addsubview instead of scrollview.addsubview, they were displayed just not scrolling since not a part of the scrollview anymore.
I even removed the label to make sure that the buttons were not being overlapped(didn't work either)
I also tried to see the code in "code debug hierarchy " (3D mode), i couldn't see the button there either even though i had added it
Below is my code with an example of label, scrollview and button. It be great if anyone could provide any insights.....thanks either way....
................scrollview..........................
var editInfoView : UIScrollView = {
let view = UIScrollView()
view.translatesAutoresizingMaskIntoConstraints = false
view.contentSize.height = 700
view.backgroundColor = tableBackGroundColor
view.frame = CGRect(x: 0, y: 220, width: 375, height: 400)
return view
}()
.......................label...................
vehicleNumberLabel.translatesAutoresizingMaskIntoConstraints = false
vehicleNumberLabel.textColor = .white
vehicleNumberLabel.text = "Vehicle Number"
vehicleNumberLabel.textAlignment = .left
editInfoView.addSubview(vehicleNumberLabel)
vehicleNumberLabel.leftAnchor.constraint(equalTo: editInfoView.leftAnchor).isActive = true
vehicleNumberLabel.topAnchor.constraint(equalTo: editInfoView.topAnchor, constant: 100).isActive = true
vehicleNumberLabel.widthAnchor.constraint(equalToConstant: 160).isActive = true
vehicleNumberLabel.heightAnchor.constraint(equalToConstant: 20).isActive = true
.....................button................................
vehicleNumberButton.translatesAutoresizingMaskIntoConstraints = false
vehicleNumberButton.setTitleColor(tableTextColor, for: .normal)
vehicleNumberButton.setTitle("Vehicle Number", for: .normal)
vehicleNumberButton.tintColor = tableTextColor
vehicleNumberButton.backgroundColor = tableTextColor
editInfoView.addSubview(vehicleNumberButton)
vehicleNumberButton.rightAnchor.constraint(equalTo: editInfoView.rightAnchor).isActive = true
vehicleNumberButton.topAnchor.constraint(equalTo: editInfoView.topAnchor, constant: 400).isActive = true
vehicleNumberButton.widthAnchor.constraint(equalToConstant: 600).isActive = true
vehicleNumberButton.heightAnchor.constraint(equalToConstant: 255).isActive = true
Although I cannot determine the root cause of your issue with the code and explanation provided I suspect the frame of your UIScrollView() is zero after viewDidAppear(_:) adding subviews to a CGRect.zero can cause some strange behavior with the layout engine. When we create constraints programmatically we are creating a combination of inequalities, equalities, and priorities to restrict the view to a particular frame. If a the value of these constraint equations is incorrect it changes how your relating views appear. Its good practice to avoid the use of leftAnchor and rightAnchor as well, because views may flip direction based on language (writing direction) and user settings.
ViewController.swift
import UIKit
class ViewController: UIViewController {
var editInfoScrollView : UIScrollView = {
let view = UIScrollView()
view.translatesAutoresizingMaskIntoConstraints = false
view.isUserInteractionEnabled = true
view.alwaysBounceVertical = true
view.isScrollEnabled = true
view.contentSize.height = 700
view.backgroundColor = UIColor.red.withAlphaComponent(0.3)
// Does nothing because `translatesAutoresizingMaskIntoConstraints = false`
// Instead, set the content size after activating constraints in viewDidAppear
//view.frame = CGRect(x: 0, y: 220, width: 375, height: 400)
return view
}()
var vehicleNumberLabel: UILabel = {
let label = UILabel()
label.translatesAutoresizingMaskIntoConstraints = false
label.textColor = UIColor.black
label.text = "Vehicle Number"
label.textAlignment = .left
return label
}()
lazy var vehicleNumberButton: UIButton = {
let button = UIButton()
button.translatesAutoresizingMaskIntoConstraints = false
button.tag = 1
button.setTitleColor(UIColor.black, for: .normal)
button.setTitle("Go to Vehicle", for: .normal)
button.tintColor = UIColor.white
button.backgroundColor = UIColor.clear
button.layer.cornerRadius = 30 // about half of button.frame.height
button.layer.borderColor = UIColor.black.cgColor
button.layer.borderWidth = 2.0
button.layer.masksToBounds = true
button.addTarget(self, action: #selector(handelButtons(_:)), for: .touchUpInside)
return button
}()
override func viewDidLoad() {
super.viewDidLoad()
self.view.backgroundColor = UIColor.white
self.setupSubviews()
}
override func viewDidAppear(_ animated: Bool) {
super.viewDidAppear(animated)
self.editInfoScrollView.contentSize = CGSize(width: self.view.frame.width, height: 700.0)
}
func setupSubviews() {
self.view.addSubview(editInfoScrollView)
editInfoScrollView.addSubview(vehicleNumberLabel)
editInfoScrollView.addSubview(vehicleNumberButton)
let spacing: CGFloat = 12.0
let constraints:[NSLayoutConstraint] = [
editInfoScrollView.widthAnchor.constraint(equalTo: self.view.widthAnchor),
editInfoScrollView.heightAnchor.constraint(equalToConstant: 400.0),
editInfoScrollView.centerXAnchor.constraint(equalTo: self.view.centerXAnchor),
editInfoScrollView.centerYAnchor.constraint(equalTo: self.view.centerYAnchor, constant: 220.0),
vehicleNumberLabel.leadingAnchor.constraint(equalTo: editInfoScrollView.leadingAnchor, constant: spacing),
vehicleNumberLabel.trailingAnchor.constraint(equalTo: editInfoScrollView.trailingAnchor, constant: -spacing),
vehicleNumberLabel.centerXAnchor.constraint(equalTo: editInfoScrollView.centerXAnchor, constant: -50),
vehicleNumberLabel.heightAnchor.constraint(equalToConstant: 75.0),
vehicleNumberButton.widthAnchor.constraint(equalTo: editInfoScrollView.widthAnchor, multiplier: 0.66),
vehicleNumberButton.heightAnchor.constraint(equalToConstant: 65.0),
vehicleNumberButton.topAnchor.constraint(equalTo: vehicleNumberLabel.bottomAnchor, constant: spacing),
vehicleNumberButton.centerXAnchor.constraint(equalTo: editInfoScrollView.centerXAnchor),
]
NSLayoutConstraint.activate(constraints)
}
#objc func handelButtons(_ sender: UIButton) {
switch sender.tag {
case 0:
print("Default button tag")
case 1:
print("vehicleNumberButton was tapped")
default:
print("Nothing here yet")
}
}
}

How do I dynamically adjust the height of a UIView when a member stack view is no longer shown?

I am super new iOS development and StackViews in general and need help calculating dynamic height in instances where a stack view will not be shown. There are cases where certain elements will not be shown depending on what I get back from the server.
However, when I call removeArrangedSubview the element is removed but the height isn't adjusted dynamically. How can I fix this?
I would like to avoid the Interface Builder all together and just do this programmatically. I have been using layout anchors for constraints.
Here's my code. You can put in a playground to see it.
//: Playground - noun: a place where people can play
import UIKit
import Foundation
let view = UIView(frame: CGRect(x: 0, y: 0, width: 800, height: 140))
let firstStackView = UIStackView(frame: CGRectZero)
//firstStackView.heightAnchor.constraintGreaterThanOrEqualToConstant(40).active = true
firstStackView.axis = .Vertical
firstStackView.alignment = .Fill
firstStackView.distribution = .EqualSpacing
let titleStackView = UIStackView(frame: CGRectZero)
titleStackView.axis = .Horizontal
titleStackView.alignment = .Fill
titleStackView.distribution = .Fill
titleStackView.spacing = 3
firstStackView.addArrangedSubview(titleStackView)
let productStackView = UIStackView(frame: .zero)
productStackView.axis = .Horizontal
productStackView.alignment = .Leading
productStackView.distribution = .Fill
productStackView.spacing = 3
firstStackView.addArrangedSubview(productStackView)
//firstStackView.removeArrangedSubview(productStackView)
let secondStackView = UIStackView(frame: CGRectZero)
//secondStackView.heightAnchor.constraintEqualToConstant(30).active = true
secondStackView.axis = .Horizontal
secondStackView.distribution = .EqualSpacing
let title = UILabel(frame: CGRectZero)
title.text = "test1"
title.textColor = .blackColor()
//labelOne.backgroundColor = .blueColor()
let size = title.sizeThatFits(CGSizeZero)
print("\(size)")
title.widthAnchor.constraintEqualToConstant(size.width).active = true
//labelOne.heightAnchor.constraintEqualToConstant(30).active = true
titleStackView.addArrangedSubview(title)
let assigneeLabel = UILabel(frame: CGRectZero)
assigneeLabel.text = "test2"
assigneeLabel.textColor = .blackColor()
//labelTest.backgroundColor = .redColor()
assigneeLabel.textAlignment = .Left
//labelTest.heightAnchor.constraintEqualToConstant(30).active = true
titleStackView.addArrangedSubview(assigneeLabel)
let actions = UIButton(type: .Custom)
//buttonOne.backgroundColor = .redColor()
actions.setTitle("some button", forState: .Normal)
actions.setTitleColor(.blackColor(), forState: .Normal)
titleStackView.addArrangedSubview(actions)
let productOne = UILabel(frame: CGRectZero)
productOne.text = "something1"
productOne.numberOfLines = 0
let productLabelSize = productOne.sizeThatFits(CGSizeZero)
productOne.widthAnchor.constraintEqualToConstant(productLabelSize.width).active = true
productOne.textColor = .blackColor()
//labelTwo.backgroundColor = .blueColor()
productStackView.removeArrangedSubview(productOne)
//productStackView.addArrangedSubview(productOne)
let productTwo = UILabel(frame: CGRectZero)
productTwo.text = "something2"
productTwo.numberOfLines = 0
//productTwo.heightAnchor.constraintEqualToConstant(30).active = true
productTwo.textColor = .blackColor()
//labelTwo.backgroundColor = .blueColor()
productStackView.removeArrangedSubview(productTwo)
//productStackView.addArrangedSubview(productTwo)
let labelThree = UILabel(frame: CGRectZero)
labelThree.text = "sometime"
//labelThree.heightAnchor.constraintEqualToConstant(30).active = true
labelThree.textColor = .blackColor()
//labelThree.backgroundColor = .blueColor()
firstStackView.addArrangedSubview(labelThree)
let descriptionView = UILabel(frame: CGRectZero)
descriptionView.text = "some description about something"
descriptionView.textColor = .blackColor()
//descriptionView.backgroundColor = .redColor()
secondStackView.addArrangedSubview(descriptionView)
let tagsView = UILabel(frame: CGRectZero)
tagsView.text = "some more things"
tagsView.textColor = .blackColor()
secondStackView.addArrangedSubview(tagsView)
secondStackView.trailingAnchor.constraintEqualToAnchor(tagsView.trailingAnchor).active = true
let stackView = UIStackView(arrangedSubviews: [firstStackView, secondStackView])
stackView.layoutMargins = UIEdgeInsets(top: 0, left: 20, bottom: 0, right: 20)
stackView.layoutMarginsRelativeArrangement = true
stackView.axis = .Vertical
stackView.frame = view.bounds
stackView.distribution = .FillProportionally
view.addSubview(stackView)
Before element is removed:
After element is removed:
I would like that gap to be gone and the height adjusted dynamically.
You can add a constraint for the height of the view if you are using auto layout.
So like for initial setup, you could do something like:
class YourClass : UIViewController() {
var heightConstraint = NSLayoutConstraint()
func someMethod () {
// load your View
// get the height of view.
heightConstraint = yourView.heightAnchor.constraintEqualToConstant(height)
self.view.addConstraint(heightConstraint)
}
func deleteMemberStackView() {
/// After deleting the member, get the new height of the view and do this
self.view.removeConstraint(heightConstraint)
heightConstraint = yourView.heightAnchor.constraintEqualToConstant(height)
self.view.addConstraint(heightConstraint)
UIView.animateViewDuration(0.3, completion: {
self.view.layoutIfNeeded()
})
}
}