How to make custom class for auto layouts? - ios

Like we make custom classes for UIButton and other items of UIKit.
Just we define our layouts in that class and further use them as we do in case of other custom class.
If it can not happen, kindly comment that why it can't be done?

The below extension can be used for your requirement
extension UIView {
public func anchor(top: NSLayoutYAxisAnchor? = nil, left: NSLayoutXAxisAnchor? = nil, bottom: NSLayoutYAxisAnchor? = nil, right: NSLayoutXAxisAnchor? = nil, topConstant: CGFloat = 0, leftConstant: CGFloat = 0, bottomConstant: CGFloat = 0, rightConstant: CGFloat = 0, widthConstant: CGFloat = 0, heightConstant: CGFloat = 0) {
translatesAutoresizingMaskIntoConstraints = false
var anchors = [NSLayoutConstraint]()
if let top = top {
anchors.append(topAnchor.constraint(equalTo: top, constant: topConstant))
}
if let left = left {
anchors.append(leftAnchor.constraint(equalTo: left, constant: leftConstant))
}
if let bottom = bottom {
anchors.append(bottomAnchor.constraint(equalTo: bottom, constant: -bottomConstant))
}
if let right = right {
anchors.append(rightAnchor.constraint(equalTo: right, constant: -rightConstant))
}
if widthConstant > 0 {
anchors.append(widthAnchor.constraint(equalToConstant: widthConstant))
}
if heightConstant > 0 {
anchors.append(heightAnchor.constraint(equalToConstant: heightConstant))
}
anchors.forEach({$0.isActive = true})
}
public func anchor(centerX: NSLayoutXAxisAnchor? = nil, centerY: NSLayoutYAxisAnchor? = nil, xConstant: CGFloat = 0, yConstant: CGFloat = 0, widthConstant: CGFloat = 0, heightConstant: CGFloat = 0) {
self.translatesAutoresizingMaskIntoConstraints = false
var anchors = [NSLayoutConstraint]()
if let centerX = centerX {
anchors.append(centerXAnchor.constraint(equalTo: centerX, constant: xConstant))
}
if let centerY = centerY {
anchors.append(centerYAnchor.constraint(equalTo: centerY, constant: yConstant))
}
if widthConstant > 0 {
anchors.append(widthAnchor.constraint(equalToConstant: widthConstant))
}
if heightConstant > 0 {
anchors.append(heightAnchor.constraint(equalToConstant: heightConstant))
}
anchors.forEach({$0.isActive = true})
}
}
as
label.anchor(centerX: view.centerXAnchor, centerY: view.centerYAnchor, xConstant: 20, yConstant: 5, widthConstant: screenSize.width, heightConstant: height1)
and
label.anchor(top: nil, left: customCell.leftAnchor, bottom: customCell.bottomAnchor, right: customCell.rightAnchor, topConstant: 0, leftConstant: 22, bottomConstant: 0, rightConstant: 22, widthConstant: width, heightConstant: btnHeigght)

Related

ScrollView Doesn't scroll when keyboard appears If elements in a ContentView

I have UIScrollView which has a UIView (basically a content view) in it. In contentView, I have UITextFields and a UIButton. At first, elements are inside UIScrollView directly. When keyboard opens, If UITextField is below keyboard, scrollview scrolls to show the content. After, I put them inside a ContentView, It started nothing to work. What am I doing wrong?
I searched below posts but not sure why my code isn't working.
How do I scroll the UIScrollView when the keyboard appears?
P.S: I know there are lots of examples in the community but I'm not sure which will be best approach. When this one was working, It was a simple and light answer but not sure why not It isn't working.
#objc override func keyboardWillShow(notification: NSNotification){
//Need to calculate keyboard exact size due to Apple suggestions
if let frameValue = notification.userInfo?[UIResponder.keyboardFrameEndUserInfoKey] as? NSValue {
keyboardHeight = frameValue.cgRectValue.size.height
let contentInsets = UIEdgeInsets(top: 0.0, left: 0.0, bottom: keyboardHeight, right: 0.0)
self.scrollView.contentInset = contentInsets
self.scrollView.scrollIndicatorInsets = contentInsets
}
}
How I Give Constraints:
contentView.translatesAutoresizingMaskIntoConstraints = false
scrollView.addSubview(contentView)
contentView.leadingAnchor.constraint(equalTo: scrollView.leadingAnchor).isActive = true
contentView.trailingAnchor.constraint(equalTo: scrollView.trailingAnchor).isActive = true
contentView.topAnchor.constraint(equalTo: scrollView.topAnchor).isActive = true
contentView.bottomAnchor.constraint(equalTo: scrollView.bottomAnchor).isActive = true
contentView.widthAnchor.constraint(equalTo: scrollView.widthAnchor).isActive = true
scrollView.translatesAutoresizingMaskIntoConstraints = false
self.view.addSubview(scrollView)
contentView.addSubview(TextField1)
contentView.addSubview(TextField2)
contentView.addSubview(button)
scrollView.anchor(header.bottomAnchor, left: self.view.leftAnchor, bottom: self.view.bottomAnchor, right: self.view.rightAnchor, topConstant: 20, leftConstant: 0, bottomConstant: 0, rightConstant: 0, widthConstant: 0, heightConstant: 0)
TextField1.anchor(contentView.topAnchor, left: self.contentView.leftAnchor, bottom: nil, right: self.contentView.rightAnchor, topConstant: 5, leftConstant: 25, bottomConstant: 0, rightConstant: 25, widthConstant: 0, heightConstant: 70)
TextField1.widthAnchor.constraint(equalTo: self.view.widthAnchor, constant: -50).isActive = true
TextField2.anchor(TextField1.bottomAnchor, left: self.contentView.leftAnchor, bottom: nil, right: self.contentView.rightAnchor, topConstant: 5, leftConstant: 25, bottomConstant: 0, rightConstant: 25, widthConstant: 0, heightConstant: 70)
Button.anchor(TextField2.bottomAnchor, left: self.contentView.leftAnchor, bottom: self.contentView.bottomAnchor, right: self.contentView.rightAnchor, topConstant: 30, leftConstant: 25, bottomConstant: 20, rightConstant: 25, widthConstant: 0, heightConstant: 40)
EDIT: Another approach I tried (which Apple recommended). This aRect.Contains always returns true.
if let frameValue = notification.userInfo?[UIResponder.keyboardFrameEndUserInfoKey] as? NSValue {
keyboardHeight = frameValue.cgRectValue.size.height
var contentInsets: UIEdgeInsets = UIEdgeInsets(top: 0.0, left: 0.0, bottom: keyboardHeight, right: 0.0)
scrollView.contentInset = contentInsets
scrollView.scrollIndicatorInsets = contentInsets
// If active text field is hidden by keyboard, scroll it so it's visible
// Your application might not need or want this behavior.
//CGRect(x: 0, y: self.header.frame.maxY, width: self.view.frame.width, height: self.view.frame.height - self.header.frame.maxY)
var aRect: CGRect = self.view.frame
aRect.size.height -= keyboardHeight
aRect.size.height -= header.frame.maxY
if !aRect.contains(activeTextField.frame.origin) {
var scrollPoint = CGPoint(x: 0.0, y: activeTextField.frame.origin.y - (keyboardHeight))
scrollView.setContentOffset(scrollPoint, animated: true)
}
}
The simple way to achieve this is by using IQKeyboardManager library.
Checkout the link: https://github.com/hackiftekhar/IQKeyboardManager
After an hour work, I find the solution. I'm sharing the answer instead of deleting the post cuz my problem was because UIScrollView doesn't content whole screen. There is an header and a label above UIScrollView . All of the answers in the community, target If UIScroll content whole screen.
#objc override func keyboardWillShow(notification: NSNotification){
//Need to calculate keyboard exact size due to Apple suggestions
if let frameValue = notification.userInfo?[UIResponder.keyboardFrameEndUserInfoKey] as? NSValue {
keyboardHeight = frameValue.cgRectValue.size.height
let scrollViewRect: CGRect = view.convert(scrollView.frame, from: scrollView.superview)
let hiddenScrollViewRect: CGRect = scrollViewRect.intersection(frameValue.cgRectValue)
// Figure out where the two frames overlap, and set the content offset of the scrollview appropriately
let contentInsets: UIEdgeInsets = UIEdgeInsets(top: 0.0, left: 0.0, bottom: hiddenScrollViewRect.size.height, right: 0.0)
scrollView.contentInset = contentInsets
scrollView.scrollIndicatorInsets = contentInsets
var visibleRect: CGRect = activeTextField.frame
visibleRect = scrollView.convert(visibleRect, from: activeTextField.superview)
visibleRect = visibleRect.insetBy(dx: 0.0, dy: -5.0)
scrollView.scrollRectToVisible(visibleRect, animated: true)
}

How do I have to modify my UIView extension if I wanted to animate the auto layout constraints afterward?

I have made an UIView extension to set my NSLayout anchors. Everything works just fine. But how can I modify my extension if I wanted to add an NSLayoutConstraint so I could animate the constraints afterward?
Here is my current extension:
extension UIView {
func anchor(top: NSLayoutYAxisAnchor?, leading: NSLayoutXAxisAnchor?, bottom: NSLayoutYAxisAnchor?, trailing: NSLayoutXAxisAnchor?, padding: UIEdgeInsets = .zero, size: CGSize = .zero) {
//translate the view's autoresizing mask into Auto Layout constraints
translatesAutoresizingMaskIntoConstraints = false
if let top = top {
topAnchor.constraint(equalTo: top, constant: padding.top).isActive = true
}
if let leading = leading {
leadingAnchor.constraint(equalTo: leading, constant: padding.left).isActive = true
}
if let bottom = bottom {
bottomAnchor.constraint(equalTo: bottom, constant: -padding.bottom).isActive = true
}
if let trailing = trailing {
trailingAnchor.constraint(equalTo: trailing, constant: -padding.right).isActive = true
}
if size.width != 0 {
widthAnchor.constraint(equalToConstant: size.width).isActive = true
}
if size.height != 0 {
heightAnchor.constraint(equalToConstant: size.height).isActive = true
}
}
}
And here is how the extension is called:
//feedViewButton constraints
feedViewButton.anchor(top: nil, leading: nil, bottom: view.safeAreaLayoutGuide.bottomAnchor, trailing: view.trailingAnchor, padding: .init(top: 0, left: 0, bottom: 0, right: 25), size: .init(width: 50, height: 50))
UPDATE
I would like to have something like this
var topAnchor: NSLayoutConstraint?
topAnchor = topAnchor.constraint(equaltTo: top, constant: padding.top)
topAnchor.isActive = true
And then animate it like this:
let animator = UIViewPropertyAnimator(duration: 1, curve: .easeOut) {
topAnchor.constant = 20
}
animator.startAnimation()
Just try to animate it using autolayout, since the constraints haven't been applied yet, it should be animatable:
feedViewButton.anchor(top: nil, leading: nil, bottom: view.safeAreaLayoutGuide.bottomAnchor, trailing: view.trailingAnchor, padding: .init(top: 0, left: 0, bottom: 0, right: 25), size: .init(width: 50, height: 50))
feedViewButton.superview?.setNeedsLayout()
UIView.animate(withDuration: 0.2, delay: 0, options: [.allowUserInteraction], animations: {
feedViewButton.superview?.layoutIfNeeded()
}, completion: nil)
UPDATE
If you want to later change the constants on the anchors to animate some other change, you have to keep references to the constraints to be able to manipulate them later:
enum ConstraintType {
case top, leading, trailing, bottom, width, height
}
extension UIView {
func anchor(top: NSLayoutYAxisAnchor?, leading: NSLayoutXAxisAnchor?, bottom: NSLayoutYAxisAnchor?, trailing: NSLayoutXAxisAnchor?, padding: UIEdgeInsets = .zero, size: CGSize = .zero) -> [ConstraintType : NSLayoutConstraint] {
//translate the view's autoresizing mask into Auto Layout constraints
translatesAutoresizingMaskIntoConstraints = false
var constraints: [ConstraintType : NSLayoutConstraint] = [:]
if let top = top {
constraints[.top] = topAnchor.constraint(equalTo: top, constant: padding.top)
}
if let leading = leading {
constraints[.leading] = leadingAnchor.constraint(equalTo: leading, constant: padding.left)
}
if let bottom = bottom {
constraints[.bottom] = bottomAnchor.constraint(equalTo: bottom, constant: -padding.bottom)
}
if let trailing = trailing {
constraints[.trailing] = trailingAnchor.constraint(equalTo: trailing, constant: -padding.right)
}
if size.width != 0 {
constraints[.width] = widthAnchor.constraint(equalToConstant: size.width)
}
if size.height != 0 {
constraints[.height] = heightAnchor.constraint(equalToConstant: size.height)
}
let constraintsArray = Array<NSLayoutConstraint>(constraints.values)
NSLayoutConstraint.activate(constraintsArray)
return constraints
}
}
This extension returns a dictionary of constraints that you can later change and animate those changes. E.g.:
let constraints = feedViewButton.anchor(top: nil, leading: nil, bottom: view.safeAreaLayoutGuide.bottomAnchor, trailing: view.trailingAnchor, padding: .init(top: 0, left: 0, bottom: 0, right: 25), size: .init(width: 50, height: 50))
// applies the constraints
self.view.layoutIfNeeded()
// now to animate bottom to -50:
if let bottomConstraint = constraints[.bottom] {
bottomConstraint.constant = -50
self.view.setNeedsLayout()
let animator = UIViewPropertyAnimator(duration: 1, curve: .easeInOut, animations: {
self.view.layoutIfNeeded()
})
animator.startAnimation()
}
You can simply add the animation on the extension, so all calls to anchor will be animated without add the animation block always.
extension UIView {
func anchor(animated: Bool, top: NSLayoutYAxisAnchor?, leading: NSLayoutXAxisAnchor?, bottom: NSLayoutYAxisAnchor?, trailing: NSLayoutXAxisAnchor?, padding: UIEdgeInsets = .zero, size: CGSize = .zero) {
//translate the view's autoresizing mask into Auto Layout constraints
translatesAutoresizingMaskIntoConstraints = false
if let top = top {
topAnchor.constraint(equalTo: top, constant: padding.top).isActive = true
}
if let leading = leading {
leadingAnchor.constraint(equalTo: leading, constant: padding.left).isActive = true
}
if let bottom = bottom {
bottomAnchor.constraint(equalTo: bottom, constant: -padding.bottom).isActive = true
}
if let trailing = trailing {
trailingAnchor.constraint(equalTo: trailing, constant: -padding.right).isActive = true
}
if size.width != 0 {
widthAnchor.constraint(equalToConstant: size.width).isActive = true
}
if size.height != 0 {
heightAnchor.constraint(equalToConstant: size.height).isActive = true
}
if animated {
UIView.animate(withDuration: 0.2, delay: 0, options: [.allowUserInteraction], animations: {
self.layoutIfNeeded()
}, completion: nil)
} else {
self.layoutIfNeeded()
}
}
}

Swift Cannot Round the Corners of my UIButton

I've looked at almost every stackoverflow solution and for some odd reason my button will not round the corners. Can someone check and see what im doing wrong?
let goToMapsButton = UIButton(type: .custom)
scrollView.addSubview(goToMapsButton)
_ = goToMapsButton.anchor(map.bottomAnchor, left: nil, bottom: seperator.topAnchor, right: self.view.rightAnchor, topConstant: 16, leftConstant: 0, bottomConstant: 16, rightConstant: 16, widthConstant: 50, heightConstant: 50)
goToMapsButton.backgroundColor = .green
goToMapsButton.layer.cornerRadius = 0.5 * goToMapsButton.bounds.size.width
goToMapsButton.clipsToBounds = true
goToMapsButton.layer.masksToBounds = true
Btw, Im doing this all in the viewDidLoad section of the view controller, if that info makes a difference.
Here is the full viewDidLoadClass for reference:` override func viewDidLoad() {
super.viewDidLoad()
let map = MKMapView()
let view1 = UIView()
view1.backgroundColor = .red
let storeAddress = UILabel()
storeAddress.text = "318 Atwood Avenue"
storeAddress.font = UIFont.systemFont(ofSize: 20, weight: UIFont.Weight.medium)
let storeCity = UILabel()
storeCity.text = "Rainy River"
storeCity.font = UIFont.systemFont(ofSize: 20, weight: UIFont.Weight.medium)
let seperator = UIView()
seperator.backgroundColor = .lightGray
let goToMapsButton = UIButton(type: .custom)
scrollView.addSubview(map)
scrollView.addSubview(view1)
scrollView.addSubview(storeAddress)
scrollView.addSubview(storeCity)
scrollView.addSubview(goToMapsButton)
scrollView.addSubview(seperator)
map.anchorToTop(scrollView.topAnchor, left: self.view.leftAnchor, bottom: nil, right: self.view.rightAnchor)
map.heightAnchor.constraint(equalTo: self.view.heightAnchor, multiplier: 0.6).isActive = true
_ = storeAddress.anchor(map.bottomAnchor, left: self.view.leftAnchor, bottom: nil, right: nil, topConstant: 16, leftConstant: 16, bottomConstant: 0, rightConstant: 0, widthConstant: 0, heightConstant: 0)
_ = storeCity.anchor(storeAddress.bottomAnchor, left: self.view.leftAnchor, bottom: nil, right: nil, topConstant: 8, leftConstant: 16, bottomConstant: 0, rightConstant: 0, widthConstant: 0, heightConstant: 0)
_ = goToMapsButton.anchor(map.bottomAnchor, left: nil, bottom: nil, right: self.view.rightAnchor, topConstant: 16, leftConstant: 0, bottomConstant: 16, rightConstant: 16, widthConstant: 50, heightConstant: 50)
goToMapsButton.backgroundColor = .green
print(goToMapsButton.frame.width)
goToMapsButton.layer.cornerRadius = 0.25 * goToMapsButton.frame.width
goToMapsButton.clipsToBounds = true
goToMapsButton.layer.masksToBounds = true
_ = seperator.anchor(storeCity.bottomAnchor, left: self.view.leftAnchor, bottom: nil, right: self.view.rightAnchor, topConstant: 8, leftConstant: 0, bottomConstant: 0, rightConstant: 0, widthConstant: 0, heightConstant: 1)
view1.anchorToTop(map.bottomAnchor, left: self.view.leftAnchor, bottom: scrollView.bottomAnchor, right: self.view.rightAnchor)
view1.heightAnchor.constraint(equalTo: self.view.heightAnchor, multiplier: 0.8).isActive = true
}`
Move this code in viewWillLayoutSubviews:
override func viewWillLayoutSubviews() {
super.viewWillLayoutSubviews()
goToMapsButton.layer.cornerRadius = 0.25 * goToMapsButton.frame.width
}
Or create your custom class for button with rounded corners:
class RoundedButton: UIButton {
#IBInspectable var cornerRadius: CGFloat = 0
override func layoutSubviews() {
super.layoutSubviews()
clipsToBounds = true
layer.cornerRadius = cornerRadius
}
}
I face the same issue today, I'm using Anchor too. Well it looks like a one line stuff to me, never think it would takes that much of code.
The difficult is that we cannot get the frame.height or width in UIButton property closure because autolayout has not calculate the size at that time. I do a test to apply the purely round corner in viewDidLayoutSubviews.
And this is what it is looks like, although the declaration is separated for those UIButtons. I really don't like this way, I want to put all button declaration code in the same place, like a closure. However I don't find any other way to do it in internet.
let b1 = UIButton()
let b2 = UIButton()
let b3 = UIButton()
let b4 = UIButton()
override func viewDidLoad() {
super.viewDidLoad()
configureLayout()
}
private func configureLayout() {
// disable large title
navigationItem.largeTitleDisplayMode = .never
let topLabel = UILabel()
topLabel.text = "Import your music"
topLabel.font = .systemFont(ofSize: 30, weight: .heavy)
topLabel.numberOfLines = 0
topLabel.textColor = .black
topLabel.textAlignment = .center
let stack = UIStackView()
stack.translatesAutoresizingMaskIntoConstraints = false
stack.axis = .vertical
stack.spacing = 40
stack.addArrangedSubview(topLabel)
b1.setTitle("Local drive", for: .normal)
b2.setTitle("Google", for: .normal)
b3.setTitle("OneNote", for: .normal)
b4.setTitle("DropBox", for: .normal)
b1.backgroundColor = .myBlue
b2.backgroundColor = .myGreen
b3.backgroundColor = .systemPink
b4.backgroundColor = .myPuple
b1.tag = 1
b2.tag = 2
b3.tag = 3
b4.tag = 4
[b1, b2, b3, b4].forEach { b in
b.titleLabel?.font = .systemFont(ofSize: 20, weight: .bold)
b.setTitleColor(.white, for: .normal)
b.setTitleColor(.gray, for: .highlighted)
stack.addArrangedSubview(b)
b.addTarget(self, action: #selector(buttonTapped(_:)), for: .touchUpInside)
}
view.addSubview(stack)
let g = view.safeAreaLayoutGuide
NSLayoutConstraint.activate([
stack.centerXAnchor.constraint(equalTo: g.centerXAnchor),
stack.centerYAnchor.constraint(equalTo: g.centerYAnchor),
stack.widthAnchor.constraint(equalTo: g.widthAnchor, multiplier: 0.75)
])
}
override func viewDidLayoutSubviews() {
super.viewDidLayoutSubviews()
[b1, b2, b3, b4].forEach { b in
b.layer.cornerRadius = b1.frame.height / 2
b.layer.cornerCurve = .continuous
}
}
Give your button a frame. like that
goToMapsButton.frame = CGRect(x: xposition, y:yposition, width: widthyouwant, height: heightyouwant)
as currently your size of button is zero 0*0.5 = zero thats why its not applying any radius.
give it frame and it will work...
UIButton might have a background UIImage with rounded corners. It allowes you to set a background UIImage for each UIControlState of your UIButton.
open class UIButton : UIControl, NSCoding {
open func setBackgroundImage(_ image: UIImage?, for state: UIControlState)
}
If your UIButton's size is determined at runtime and the radius is fixed - you can use a resizable image:
open class UIImage : NSObject, NSSecureCoding {
open func resizableImage(withCapInsets capInsets: UIEdgeInsets) -> UIImage
}
On the gif below I use UIImage with size = CGSize(width: 7, height: 7), corner radius = 3 and cap insets = UIEdgeInsets(top: 3, left: 3, bottom: 3, right: 3)

How to integrate safeAreaInsets to current constraints extension

I created extension for the view's constraints. You can find the code in the below but after new release iPhone X we need to use safeAreaInsets but i don't know how implement that property. I'll be so glad if you could help me out.
Thanks
extension UIView {
func anchor (top: NSLayoutYAxisAnchor?, left: NSLayoutXAxisAnchor?, bottom: NSLayoutYAxisAnchor?, right: NSLayoutXAxisAnchor?, paddingTop: CGFloat, paddingLeft: CGFloat, paddingBottom: CGFloat, paddingRight: CGFloat, width: CGFloat, height: CGFloat) {
translatesAutoresizingMaskIntoConstraints = false
if let top = top {
self.topAnchor.constraint(equalTo: top, constant: paddingTop).isActive = true
}
if let left = left {
self.leftAnchor.constraint(equalTo: left, constant: paddingLeft).isActive = true
}
if let right = right {
rightAnchor.constraint(equalTo: right, constant: -paddingRight).isActive = true
}
if let bottom = bottom {
bottomAnchor.constraint(equalTo: bottom, constant: -paddingBottom).isActive = true
}
if height != 0 {
heightAnchor.constraint(equalToConstant: height).isActive = true
}
if width != 0 {
widthAnchor.constraint(equalToConstant: width).isActive = true
}
}
}
I have refactored your code to take into account the insets. Try the following:
import UIKit
extension UIView {
func anchor (top: NSLayoutYAxisAnchor?, left: NSLayoutXAxisAnchor?, bottom: NSLayoutYAxisAnchor?, right: NSLayoutXAxisAnchor?, paddingTop: CGFloat, paddingLeft: CGFloat, paddingBottom: CGFloat, paddingRight: CGFloat, width: CGFloat, height: CGFloat, enableInsets: Bool) {
var topInset = CGFloat(0)
var bottomInset = CGFloat(0)
var rightInset = CGFloat(0)
var leftInset = CGFloat(0)
if #available(iOS 11, *), enableInsets {
let insets = self.safeAreaInsets
topInset = insets.top
bottomInset = insets.bottom
rightInset = insets.right
leftInset = insets.left
}
translatesAutoresizingMaskIntoConstraints = false
if let top = top {
self.topAnchor.constraint(equalTo: top, constant: paddingTop+topInset).isActive = true
}
if let left = left {
self.leftAnchor.constraint(equalTo: left, constant: paddingLeft+leftInset).isActive = true
}
if let right = right {
rightAnchor.constraint(equalTo: right, constant: -paddingRight-rightInset).isActive = true
}
if let bottom = bottom {
bottomAnchor.constraint(equalTo: bottom, constant: -paddingBottom-bottomInset).isActive = true
}
if height != 0 {
heightAnchor.constraint(equalToConstant: height).isActive = true
}
if width != 0 {
widthAnchor.constraint(equalToConstant: width).isActive = true
}
}
}

UIView subviews not appearing

I have a view controller with a UIView. Inside that UIView I add elements like a text label. When I run my code it is not there.
import UIKit
class EventDetailViewController: UIViewController {
//variables that will hold data sent in through previous event controller
var eventImage = ""
var eventName = ""
var eventDescription = ""
var eventStreet = ""
var eventCity = ""
var eventState = ""
var eventZip = 0
var eventDate = ""
//
lazy var currentEventImage : UIImageView = {
let currentEvent = UIImageView()
let imageURL = URL(string: self.eventImage)
currentEvent.af_setImage(withURL: imageURL!)
currentEvent.clipsToBounds = true
currentEvent.translatesAutoresizingMaskIntoConstraints = false
currentEvent.contentMode = .scaleToFill
currentEvent.layer.masksToBounds = true
return currentEvent
}()
//will be responsible for creating the UIView that contains relevant event information
let eventInfoContainerView: UIView = {
let infoContainer = UIView()
infoContainer.backgroundColor = UIColor.white
infoContainer.layer.masksToBounds = true
return infoContainer
}()
lazy var eventNameLabel: UILabel = {
let currentEventName = UILabel()
currentEventName.text = self.eventName
currentEventName.translatesAutoresizingMaskIntoConstraints = false
return currentEventName
}()
override func viewDidLoad() {
super.viewDidLoad()
view.backgroundColor = UIColor.white
navigationItem.title = eventName
self.navigationItem.hidesBackButton = true
let backButton = UIBarButtonItem(image: UIImage(named: "icons8-Back-64"), style: .plain, target: self, action: #selector(GoBack))
self.navigationItem.leftBarButtonItem = backButton
//Subviews will be added here
view.addSubview(currentEventImage)
view.addSubview(eventInfoContainerView)
eventInfoContainerView.addSubview(eventNameLabel)
//Constraints will be added here
_ = currentEventImage.anchor(view.centerYAnchor, left: nil, bottom: nil, right: nil, topConstant: -305, leftConstant: 0, bottomConstant: 0, rightConstant: 0, widthConstant: self.view.frame.width, heightConstant: 200)
_ = eventInfoContainerView.anchor(currentEventImage.bottomAnchor, left: view.leftAnchor, bottom: view.bottomAnchor, right: view.rightAnchor, topConstant: 0, leftConstant: 0, bottomConstant: 0, rightConstant: 0, widthConstant: 0, heightConstant: 0)
_ = eventNameLabel.anchor(eventInfoContainerView.bottomAnchor, left: view.leftAnchor, bottom: nil, right: nil, topConstant: 20, leftConstant: 32, bottomConstant: 0, rightConstant: 0, widthConstant: 0, heightConstant: 0)
}
func GoBack(){
_ = self.navigationController?.popViewController(animated: true)
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
}
I am kind of lost I viewed a tutorial where they added elements to a UIView in a similar fashion and things appeared. Any insight would be helpful. Tried changing multiple things and nothing really made it appear and I have researched a couple answers I know it is probably something small that my eyes are just looking past but I can't discover it at this point.
This is my custom method for setting constraints
import UIKit
extension UIView {
func anchorToTop(_ top: NSLayoutYAxisAnchor? = nil, left: NSLayoutXAxisAnchor? = nil, bottom: NSLayoutYAxisAnchor? = nil, right: NSLayoutXAxisAnchor? = nil) {
anchorWithConstantsToTop(top, left: left, bottom: bottom, right: right, topConstant: 0, leftConstant: 0, bottomConstant: 0, rightConstant: 0)
}
func anchorWithConstantsToTop(_ top: NSLayoutYAxisAnchor? = nil, left: NSLayoutXAxisAnchor? = nil, bottom: NSLayoutYAxisAnchor? = nil, right: NSLayoutXAxisAnchor? = nil, topConstant: CGFloat = 0, leftConstant: CGFloat = 0, bottomConstant: CGFloat = 0, rightConstant: CGFloat = 0) {
translatesAutoresizingMaskIntoConstraints = false
if let top = top {
topAnchor.constraint(equalTo: top, constant: topConstant).isActive = true
}
if let bottom = bottom {
bottomAnchor.constraint(equalTo: bottom, constant: -bottomConstant).isActive = true
}
if let left = left {
leftAnchor.constraint(equalTo: left, constant: leftConstant).isActive = true
}
if let right = right {
rightAnchor.constraint(equalTo: right, constant: -rightConstant).isActive = true
}
}
func anchor(_ top: NSLayoutYAxisAnchor? = nil, left: NSLayoutXAxisAnchor? = nil, bottom: NSLayoutYAxisAnchor? = nil, right: NSLayoutXAxisAnchor? = nil, topConstant: CGFloat = 0, leftConstant: CGFloat = 0, bottomConstant: CGFloat = 0, rightConstant: CGFloat = 0, widthConstant: CGFloat = 0, heightConstant: CGFloat = 0) -> [NSLayoutConstraint] {
translatesAutoresizingMaskIntoConstraints = false
var anchors = [NSLayoutConstraint]()
if let top = top {
anchors.append(topAnchor.constraint(equalTo: top, constant: topConstant))
}
if let left = left {
anchors.append(leftAnchor.constraint(equalTo: left, constant: leftConstant))
}
if let bottom = bottom {
anchors.append(bottomAnchor.constraint(equalTo: bottom, constant: -bottomConstant))
}
if let right = right {
anchors.append(rightAnchor.constraint(equalTo: right, constant: -rightConstant))
}
if widthConstant > 0 {
anchors.append(widthAnchor.constraint(equalToConstant: widthConstant))
}
if heightConstant > 0 {
anchors.append(heightAnchor.constraint(equalToConstant: heightConstant))
}
anchors.forEach({$0.isActive = true})
return anchors
}
}
OK - now that we see your .anchor(...) function...
The TOP of your label is set to the BOTTOM of eventInfoContainerView with topConstant: 20 ... which is +20
Change that value to -20 (assuming you want the label along the bottom of the view):
_ = eventNameLabel.anchor(eventInfoContainerView.bottomAnchor, left: view.leftAnchor, bottom: nil, right: nil, topConstant: -20, leftConstant: 32, bottomConstant: 0, rightConstant: 0, widthConstant: 0, heightConstant: 0)
Assuming your .anchor(...) function / extension is working properly, I think the only thing wrong is that you forgot to set:
infoContainer.translatesAutoresizingMaskIntoConstraints = false
when you initialize your eventInfoContainerView

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