is there a UIKit equivalent to SwiftUI's zstack? - ios

I'm trying to create something like this. I've been working with SwiftUI recently so I know I could create that by adding an image, text and button (the I'm flexible text is the label for a button/NavigationLink) to a zstack. but I'm looking around trying to see if there's anyway to do that in UIKit. preferably without using storyboards. I'm open to a cocoapods library or whatever if that's what it takes. I've looked around and explored using SwiftUI to create the desired ZStack and then use it in my UIKit with a UIHostingController but because it involves a button/navigationlink. seeing as how the NavigationLink would require the destination to conform to a View, I wanted to ask around before converting even more of my project to swiftui. I was more hoping this project would be for giving me more experience building views in UIKit without storyboards so I'd prefer to do that instead of using SwiftUI. if that's possible I guess.
I've tried searching around but all my google searches involving UIButtons and images just link to posts about setting the image in a UIButton.

since you wanted to get more experience in creating views using UIKit, I've created a view that inherits from UIView that you can reuse. There's quite a lot of code to get the same result in UIKit. The code and output are provided below.
NOTE: Read the comments provided
Code
class ImageCardWithButton: UIView {
lazy var cardImage: UIImageView = {
let image = UIImageView()
image.translatesAutoresizingMaskIntoConstraints = false // To flag that we are using Constraints to set the layout
image.image = UIImage(named: "dog")
image.contentMode = .scaleAspectFill
return image
}()
lazy var gradientView: UIView = {
let view = UIView()
view.translatesAutoresizingMaskIntoConstraints = false // IMPORTANT IF YOU ARE USING CONSTRAINTS INSTEAD OF FRAMES
return view
}()
// VStack equivalent in UIKit
lazy var contentStack: UIStackView = {
let stack = UIStackView()
stack.translatesAutoresizingMaskIntoConstraints = false
stack.axis = .vertical
stack.distribution = .fillProportionally // Setting the distribution to fill based on the content
return stack
}()
lazy var titleLabel: UILabel = {
let label = UILabel()
label.textAlignment = .center
label.numberOfLines = 0 // Setting line number to 0 to allow sentence breaks
label.text = "Let your curiosity do the booking"
label.font = UIFont(name: "Raleway-Semibold", size: 20) // Custom font defined for the project
label.textColor = .white
return label
}()
lazy var cardButton: UIButton = {
let button = UIButton()
button.translatesAutoresizingMaskIntoConstraints = false
button.backgroundColor = .white
button.setTitle("I'm flexible", for: .normal)
button.setTitleColor(.blue, for: .normal)
// button.addTarget(self, action: #selector(someObjcMethod), for: .touchUpInside) <- Adding a touch event and function to invoke
return button
}()
override init(frame: CGRect) {
super.init(frame: frame)
commonInit()
}
required init?(coder: NSCoder) {
super.init(coder: coder)
commonInit()
}
private func commonInit() {
self.addSubview(cardImage) // Adding the subview to the current view. i.e., self
// Setting the corner radius of the view
self.layer.cornerRadius = 10
self.layer.masksToBounds = true
NSLayoutConstraint.activate([
cardImage.leadingAnchor.constraint(equalTo: self.leadingAnchor),
cardImage.trailingAnchor.constraint(equalTo: self.trailingAnchor),
cardImage.topAnchor.constraint(equalTo: self.topAnchor),
cardImage.bottomAnchor.constraint(equalTo: self.bottomAnchor),
])
setupGradientView()
addTextAndButton()
}
private func setupGradientView() {
let height = self.frame.height * 0.9 // Height of the translucent gradient view
self.addSubview(gradientView)
NSLayoutConstraint.activate([
gradientView.leadingAnchor.constraint(equalTo: self.leadingAnchor),
gradientView.trailingAnchor.constraint(equalTo: self.trailingAnchor),
gradientView.bottomAnchor.constraint(equalTo: self.bottomAnchor),
gradientView.heightAnchor.constraint(equalToConstant: height)
])
// Adding the gradient
let colorTop = UIColor.clear
let colorBottom = UIColor.black
let gradientLayer = CAGradientLayer()
gradientLayer.colors = [colorTop.cgColor, colorBottom.cgColor]
gradientLayer.locations = [0.0, 1.0]
gradientLayer.frame = CGRect(
x: 0,
y: self.frame.height - height,
width: self.frame.width,
height: height)
gradientView.layer.insertSublayer(gradientLayer, at:0)
print(self.frame)
}
private func addTextAndButton() {
// Adding the views to the stackview
contentStack.addArrangedSubview(titleLabel)
contentStack.addArrangedSubview(cardButton)
gradientView.addSubview(contentStack)
NSLayoutConstraint.activate([
contentStack.leadingAnchor.constraint(equalTo: self.leadingAnchor, constant: 20),
contentStack.trailingAnchor.constraint(equalTo: self.trailingAnchor, constant: -20), // Negative for leading and bottom constraints
contentStack.bottomAnchor.constraint(equalTo: self.bottomAnchor, constant: -20), // Negative for leading and bottom constraints
cardButton.heightAnchor.constraint(equalToConstant: 60)
])
cardButton.layer.cornerRadius = 30 // Half of the height of the button
}
}
Output
Important pointers
You can create the layout using constraints or frames. In case you are using constraints, it is important to set a views .translatesAutoresizingMaskIntoConstraints to false (You can read the documentation for it).
NSLayoutConstraint.activate([...]) Is used to apply an array of constraints at once. Alternatively, you can use:
cardImage.leadingAnchor.constraint(...)isActivated = true
for individual constraints
Manual layout of the views will sometimes require padding. So for this you will have to use negative or positive values for the padding based on the edge (side) of the view you are in. It's easy to remember to set the value of the padding in the direction of the centre of the view.
E.x., From the leading/left edge, you will need to add a padding of 10 towards the centre of the view or -10 from the right/trailing side towards the centre.

Related

Constraints Issues On UI button

While practicing programmatic constraints using anchors ,I came across a problem that hides the visibility of the button when using an iPhone 8 or 8 plus simulator as shown in the image below. This is due to the current coordinate values I set for the button. However the button becomes visible when I switch to an iPhone 12. How do I set the co-ordinate values in a way that makes the button visible and in same positions on the iPhone 8 or 8 plus ?
let iosImageView: UIImageView = {
let imageview = UIImageView(image: #imageLiteral(resourceName: "icons8-ios-logo-128"))
imageview.translatesAutoresizingMaskIntoConstraints = false
return imageview
}()
let press: UIButton = {
let buttonPress = UIButton.init(type: .roundedRect)
buttonPress.setTitle("Tap Me", for: .normal)
buttonPress.backgroundColor = .black
buttonPress.frame = CGRect(x: 110, y: 700, width: 200, height: 50)
return buttonPress
}()
override func viewDidLoad() {
super.viewDidLoad()
addSubviews()
setConstraints()
// Do any additional setup after loading the view.
}
func addSubviews(){
view.addSubview(iosImageView)
view.addSubview(press)
}
func setConstraints(){
NSLayoutConstraint.activate([
iosImageView.centerXAnchor.constraint(equalTo: view.centerXAnchor),
iosImageView.topAnchor.constraint(equalTo: view.topAnchor, constant: 200),
iosImageView.widthAnchor.constraint(equalToConstant: 200),
iosImageView.heightAnchor.constraint(equalToConstant: 200),
press.centerXAnchor.constraint(equalTo: view.centerXAnchor),
press.leadingAnchor.constraint(equalTo: view.leadingAnchor),
press.trailingAnchor.constraint(equalTo: view.trailingAnchor)
])
}
Your constraints for press are invalid. You failed to specify a vertical position. And you forgot to set translatesAutoresizingMaskIntoConstraints to be false. I’m surprised the button ever appears.
(Also cut the line about buttonPress.frame. Frame and constraints are opposites; use one or the other.)

Swift UIView Subviews not rounding corners in Custom UIView Subclass

Greetings stack overflow.
I am trying to build a "bullseye" type view, using coloured subviews and the corner radius. The problem I have is, only my first subview's corners are getting rounded and the inner views are still squares. The black view is a subview of my custom view. The red view is it's subview, and they yellow view the subview of that. Pretty simple hierarchy.
The result looks like this:
I add the views and set their constraints manually. My test app just has the ThreeCircleView dead center of a view controller with the X,Y centered and the width, height constant. I do the actual rounding of the corners in didLayoutSubViews because the size of the view might change, so the corners would have to be resized.
I wrote a test view to isolate this, here it is
class ThreeCircleView: UIView {
var outerCircle: UIView = UIView()
var middleCircle: UIView = UIView()
var innerCircle: UIView = UIView()
override init(frame: CGRect) {
super.init(frame: frame)
translatesAutoresizingMaskIntoConstraints = false
addSubViews()
}
required init?(coder: NSCoder) {
super.init(coder: coder)
translatesAutoresizingMaskIntoConstraints = false
addSubViews()
}
func addSubViews() {
outerCircle.backgroundColor = .black
middleCircle.backgroundColor = .red
innerCircle.backgroundColor = .yellow
self.addSubview(outerCircle)
outerCircle.addSubview(middleCircle)
middleCircle.addSubview(innerCircle)
let outerCenterY = outerCircle.centerYAnchor.constraint(equalTo: self.centerYAnchor)
let outerCenterX = outerCircle.centerXAnchor.constraint(equalTo: self.centerXAnchor)
let outerCenterWidth = outerCircle.widthAnchor.constraint(equalTo: self.widthAnchor, constant: -50.0 )
let outerCenterHeight = outerCircle.heightAnchor.constraint(equalTo: self.heightAnchor, constant: -50.0 )
outerCircle.translatesAutoresizingMaskIntoConstraints = false
NSLayoutConstraint.activate([outerCenterY,outerCenterX,outerCenterWidth,outerCenterHeight])
self.setNeedsLayout()
let middleCenterY = middleCircle.centerYAnchor.constraint(equalTo: self.centerYAnchor)
let middleCenterX = middleCircle.centerXAnchor.constraint(equalTo: self.centerXAnchor)
let middleCenterWidth = middleCircle.widthAnchor.constraint(equalTo: self.widthAnchor, constant: -100.0 )
let middleCenterHeight = middleCircle.heightAnchor.constraint(equalTo: self.heightAnchor, constant: -100.0 )
middleCircle.translatesAutoresizingMaskIntoConstraints = false
NSLayoutConstraint.activate([middleCenterY,middleCenterX,middleCenterWidth,middleCenterHeight])
let innerCenterY = innerCircle.centerYAnchor.constraint(equalTo: self.centerYAnchor)
let innerCenterX = innerCircle.centerXAnchor.constraint(equalTo: self.centerXAnchor)
let innerCenterWidth = innerCircle.widthAnchor.constraint(equalTo: self.widthAnchor, constant: -150.0 )
let innerCenterHeight = innerCircle.heightAnchor.constraint(equalTo: self.heightAnchor, constant: -150.0 )
innerCircle.translatesAutoresizingMaskIntoConstraints = false
NSLayoutConstraint.activate([innerCenterY,innerCenterX,innerCenterWidth,innerCenterHeight])
}
func makeCircle(v:UIView) {
v.layer.cornerRadius = v.frame.size.width * 0.50
v.clipsToBounds = true
}
override func layoutSubviews() {
super.layoutSubviews()
makeCircle(v: outerCircle)
makeCircle(v: middleCircle)
makeCircle(v: innerCircle)
}
}
An easy way to make it look as expected is to add layoutIfNeeded() call inside your makeCircle(v:UIView) method. This will make you sure that all views' frames are updated correctly before applying visual changes:
func makeCircle(v:UIView) {
v.layoutIfNeeded()
v.layer.cornerRadius = v.frame.size.width * 0.50
v.clipsToBounds = true
}

Wrap label around UIbutton

I'm trying to create a view like below using storyboard in Xcode.
For this, I've added a button and a label with constraints but this is the result I get. The text doesn't start below the checkbox. One way to achieve this would be to create 2 labels and add the strings that start after this string to 2 label and place it under the first label.
Is there any better way to do this? Also, when you click on Read more the text can expand as well.
You can make the leading of the button and the label the same ( button above label ) and insert some empty characters at the beginning of the label text
You can do a way. Take the button and the label in a view
then sub divide the view into two views, left one holds the button and right one holds the label. make a gap between left and right
button's constraint will be leading , top and trailing to zero and height as your wish
label's constraint will be leading , top, trailing and bottom.
You can accomplish this by using a UITextView and setting an ExclusionPath.
The ExclusionPath (or paths) defines an area within the text view's textContainer around which the text should wrap.
If you disable scrolling, selection and editing of the UITextView it will behave just like a UILabel but will also give you the benefit of ExclusionPath
Here is a simple example - lots of hard-coded values, so you'd probably want to make it a custom class - but this should get you on your way:
class TextViewLabel: UITextView {
override init(frame: CGRect, textContainer: NSTextContainer?) {
super.init(frame: frame, textContainer: textContainer)
commonInit()
}
required init?(coder aDecoder: NSCoder) {
super.init(coder: aDecoder)
commonInit()
}
func commonInit() -> Void {
isScrollEnabled = false
isEditable = false
isSelectable = false
textContainerInset = UIEdgeInsets.zero
textContainer.lineFragmentPadding = 0
}
}
class ExclusionViewController: UIViewController {
let checkBox: UIButton = {
let v = UIButton()
v.translatesAutoresizingMaskIntoConstraints = false
return v
}()
let theTextViewLabel: TextViewLabel = {
let v = TextViewLabel()
v.translatesAutoresizingMaskIntoConstraints = false
v.backgroundColor = .yellow
v.text = "I agree to receive information about this application and all the updates related to this..."
v.font = UIFont.systemFont(ofSize: 20.0)
return v
}()
var isChecked: Bool = false
override func viewDidLoad() {
super.viewDidLoad()
view.addSubview(theTextViewLabel)
theTextViewLabel.addSubview(checkBox)
let cbWidth = CGFloat(20)
NSLayoutConstraint.activate([
theTextViewLabel.topAnchor.constraint(equalTo: view.topAnchor, constant: 100.0),
theTextViewLabel.leadingAnchor.constraint(equalTo: view.leadingAnchor, constant: 40.0),
theTextViewLabel.widthAnchor.constraint(equalToConstant: 240.0),
checkBox.topAnchor.constraint(equalTo: theTextViewLabel.topAnchor, constant: 2.0),
checkBox.leadingAnchor.constraint(equalTo: theTextViewLabel.leadingAnchor, constant: 0.0),
checkBox.widthAnchor.constraint(equalToConstant: cbWidth),
checkBox.heightAnchor.constraint(equalToConstant: cbWidth),
])
theTextViewLabel.textContainer.exclusionPaths = [
UIBezierPath(rect: CGRect(x: 0, y: 0, width: cbWidth + 8.0, height: cbWidth))
]
updateCheckboxImage()
checkBox.addTarget(self, action: #selector(checkBoxTapped), for: .touchUpInside)
}
func updateCheckboxImage() -> Void {
if isChecked {
checkBox.setImage(UIImage(named: "SmallChecked"), for: .normal)
} else {
checkBox.setImage(UIImage(named: "SmallUnChecked"), for: .normal)
}
}
#objc func checkBoxTapped() -> Void {
isChecked = !isChecked
updateCheckboxImage()
}
}
Result:
(I used these two images for the checkBox):

Dynamically size UIStackView to the width of the UIViews inside

I am trying to create a UIStackView with three UIViews inside. The UIViews will have a circle with text over / in it.
I would like not to set the StackView to a static number, i would like it to be able to get smaller/grow based on the device the user is using.
Right now, the StackView is being added to the view, and the UIViews are being added to that. The colors are being displayed, but the rounded circles are not and the StackView height is not equal to the leftui's width.
Basically, I need three circles of equal height and width....is there a better way for this?
Here is my code.
#IBOutlet var stack: UIStackView!
override func viewWillLayoutSubviews() {
//let stack = UIStackView()
let leftui = UIView()
let middleui = UIView()
let rightui = UIView()
stack.addArrangedSubview(leftui)
stack.addArrangedSubview(middleui)
stack.addArrangedSubview(rightui)
leftui.backgroundColor = UIColor.red
middleui.backgroundColor = UIColor.blue
rightui.backgroundColor = UIColor.brown
leftui.bounds.size.height = leftui.bounds.width //needs these to new equal
middleui.bounds.size.height = middleui.bounds.width //needs these to new equal
rightui.bounds.size.height = rightui.bounds.width //needs these to new equal
leftui.layer.cornerRadius = leftui.bounds.size.width / 2
middleui.layer.cornerRadius = middleui.bounds.size.width / 2
rightui.layer.cornerRadius = rightui.bounds.size.width / 2
print(leftui.bounds.size.width) //prints 0.0
leftui.clipsToBounds = true
middleui.clipsToBounds = true
rightui.clipsToBounds = true
stack.sizeToFit()
stack.layoutIfNeeded()
view.addSubview(stack)
}
Here is what I was looking for.
This is from the android version of the application.
I think that in order for UIStackView to work its arrangedSubviews have to use autolayout - Check first answer here: Is it necessary to use autolayout to use stackview
This is how you could solve this:
Add a new class for your circular views, these do not do much other than set its layer.cornerRadius to half of their width, so that if height and width are the same they will be circular.
class CircularView: UIView {
override func layoutSubviews() {
super.layoutSubviews()
clipsToBounds = true
layer.cornerRadius = bounds.midX
}
}
You add a widthConstraint with which you will be able to size the elements in the stack view
var widthConstraint: NSLayoutConstraint!
You can then create the UIStackView, I used your code mostly to do this:
override func viewDidLoad() {
super.viewDidLoad()
let leftui = CircularView()
let middleui = CircularView()
let rightui = CircularView()
leftui.translatesAutoresizingMaskIntoConstraints = false
middleui.translatesAutoresizingMaskIntoConstraints = false
rightui.translatesAutoresizingMaskIntoConstraints = false
leftui.backgroundColor = UIColor.red
middleui.backgroundColor = UIColor.blue
rightui.backgroundColor = UIColor.brown
let stack = UIStackView(arrangedSubviews: [leftui, middleui, rightui])
stack.translatesAutoresizingMaskIntoConstraints = false
view.addSubview(stack)
widthConstraint = leftui.widthAnchor.constraint(equalToConstant: 100)
NSLayoutConstraint.activate([
widthConstraint,
stack.centerXAnchor.constraint(equalTo: view.centerXAnchor),
stack.centerYAnchor.constraint(equalTo: view.centerYAnchor),
leftui.heightAnchor.constraint(equalTo: leftui.widthAnchor, multiplier: 1.0),
middleui.widthAnchor.constraint(equalTo: leftui.widthAnchor, multiplier: 1.0),
middleui.heightAnchor.constraint(equalTo: leftui.widthAnchor, multiplier: 1.0),
rightui.widthAnchor.constraint(equalTo: leftui.widthAnchor, multiplier: 1.0),
rightui.heightAnchor.constraint(equalTo: leftui.widthAnchor, multiplier: 1.0)
])
}
Given the constraints set here, circles will have a width/height of 100 and stack view is centred in the view.
Next if you want to do something when view rotates you could implement something like this in your viewController
override func viewWillTransition(to size: CGSize, with coordinator: UIViewControllerTransitionCoordinator) {
coordinator.animate(alongsideTransition: { _ in
if size.width > size.height {
self.widthConstraint.constant = 150
} else {
self.widthConstraint.constant = 100
}
}, completion: nil)
}
It would animate to circles of width/height of 150 in landscape. You can then play with these values to get desired outcome.
To design this, follow the below steps.
create a custom view. in the custom view put all the subviews like
cost title label, price label and the color UIImageView
Now create three object of the custom view with proper data.
Get the device screen width divide by 3 gives each custom view
width, also set the view height as per your requirement and provide
frame for the created custom view
Now add the three views to the StackView.
Hope this will help to design, if you need any more help please comment.

Custom navigation bar title gets clipped after user leaves view controller

I need to extend my navigation bar height but since Apple made it very hard to change the navigation bar height in iOS 11 I decided I needed to use a custom view which extended the navigation bar without the user noticing.
I've created a custom view to add to the bottom of the navigation bar. I made it red just for the sake of making this question more clear. When the user leaves the view controller and then comes back, the title view custom view is "clipped" by the red view. Why?
I've tried to set clipsToBounds false on the custom title view, but that didn't help. How can I make sure the custom title view always stays on top of everything? Why is it being clipped and overlapped by the little red view (whose main purpose is to "extend" the navigation bar)?
Note: "Monthly Spending" label is part of the title view being clipped.
class ViewController: UIViewController {
let customTitleView = CustomTitleView()
let navigationBarExtensionView: UIView = {
let view = UIView()
view.backgroundColor = .red
view.translatesAutoresizingMaskIntoConstraints = false
return view
}()
override func viewDidLoad() {
super.viewDidLoad()
setupAdditionalGradientView()
navigationItem.titleView = customTitleView
}
internal func setupAdditionalGradientView() {
view.addSubview(navigationBarExtensionView)
navigationBarExtensionView.topAnchor.constraint(equalTo: view.topAnchor).isActive = true
navigationBarExtensionView.rightAnchor.constraint(equalTo: view.rightAnchor).isActive = true
navigationBarExtensionView.leftAnchor.constraint(equalTo: view.leftAnchor).isActive = true
navigationBarExtensionView.heightAnchor.constraint(equalToConstant: 18).isActive = true
// Hide pixel shadow between nav bar and red bar
navigationController?.navigationBar.shadowImage = UIImage()
navigationController?.navigationBar.layer.shadowRadius = 0
navigationController?.navigationBar.layer.shadowOffset = CGSize(width: 0, height: 0)
}
}
Custom title view:
import UIKit
class CustomTitleView: UIView {
let primaryLabel: UILabel = {
let label = UILabel()
label.text = "$10,675.00"
label.font = UIFont.systemFont(ofSize: 27.99, weight: .medium)
label.textColor = .white
label.textAlignment = .center
return label
}()
let secondaryLabel: UILabel = {
let label = UILabel()
label.text = "Monthly Spending"
label.textColor = .white
label.textAlignment = .center
label.font = UIFont.systemFont(ofSize: 10, weight: .medium)
return label
}()
let stackView: UIStackView = {
let stackView = UIStackView()
stackView.axis = .vertical
stackView.distribution = .fillProportionally
stackView.alignment = .center
stackView.translatesAutoresizingMaskIntoConstraints = false
return stackView
}()
override init(frame: CGRect) {
super.init(frame: frame)
setupStackView()
}
internal func setupStackView() {
addSubview(stackView)
stackView.addArrangedSubview(primaryLabel)
stackView.addArrangedSubview(secondaryLabel)
stackView.centerXAnchor.constraint(equalTo: centerXAnchor).isActive = true
stackView.centerYAnchor.constraint(equalTo: centerYAnchor, constant: 10).isActive = true
}
required init?(coder aDecoder: NSCoder) {
super.init(coder: aDecoder)
}
}
In iOS 11, a custom bar button item view such as your titleView is sized from the inside out using constraints. Thus, you need constraints to size the view correctly. You are not providing any constraints, so the runtime doesn't know how to size the title view.
However, I would suggest that you just give up on the dubious idea of extending your UINavigationItem's custom view downward below the outside of the navigation bar, and instead, just show the words Monthly Spending in your view controller's view.

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