UISearchBar not getting centered when pinned below a UINavigationBar - swift

I have this code below who configures the constraints of the view:
func configNavigationBarConstraints() {
navigationBar.autoPinEdge(toSuperviewEdge: .leading)
navigationBar.autoPinEdge(toSuperviewEdge: .trailing)
if #available(iOS 11.0, *) {
navigationBar.topAnchor.constraint(equalTo: view.safeAreaLayoutGuide.topAnchor).isActive = true
return
}
navigationBar.topAnchor.constraint(equalTo: topLayoutGuide.bottomAnchor).isActive = true
}
func configSearchBarConstraints() {
searchBar.autoPinEdge(.top, to: .bottom, of: navigationBar)
// taskHistorySearchBar.autoPinEdge(.top, to: .bottom, of: navigationBar, withOffset: 6) //This is a solution but no ideal, the height diff varies by device
searchBar.autoPinEdge(toSuperviewEdge: .left)
searchBar.autoPinEdge(toSuperviewEdge: .right)
}
This results into this view:
Note that the UISearchBar is not aligned, any idea of what I can do? Even if I set it to have a high height value by constraint, the center is offset.

You probably set the UINavigationBar's delegate and UISearchBar's delegate, both extends UIBarPositioningDelegate, so you need to do this:
extension ViewController: UINavigationBarDelegate {
func position(for bar: UIBarPositioning) -> UIBarPosition {
if bar is UINavigationBar {
return .topAttached
}
return .any
}
}
This will only apply the .topAttached setting for the UINavigationBar.

Related

Using UIScrollView correctly in SwiftUI

I wanted to implement pull to refresh for Scrollview of SwiftUi and so I tried to use the UIScrollView of UIKit to make use of its refreshControl. But I am getting a problem with the UIScrollview. There are several different views inside the scrollview and all of its data is fetched from network service using different API call and once the first api data is received the first view is shown inside the scrollview, similarly when second api data is received the second view is appended to the scrollview and similarly step by step all views are added to scrollview. Now in this process of step by step adding view, the scrollview doesn't get scrolled and its contents remain hiding above the navigationbar and below the bottom toolbar (may be the scrollView height takes full height of contents). But if i load the scrollView only after all the subview data is ready all subviews are loaded together then there is no issue. But i want to load the subviews as soon as i get the first data without waiting for all the data of every subviews to load completely.
The code that I have used is -
//UIScrollView
struct HomeScrollView: UIViewRepresentable {
private let uiScrollView: UIScrollView
init<Content: View>(#ViewBuilder content: () -> Content) {
let hosting = UIHostingController(rootView: content())
hosting.view.translatesAutoresizingMaskIntoConstraints = false
uiScrollView = UIScrollView()
uiScrollView.addSubview(hosting.view)
uiScrollView.showsVerticalScrollIndicator = false
uiScrollView.contentInsetAdjustmentBehavior = .never
let constraints = [
hosting.view.leadingAnchor.constraint(equalTo: uiScrollView.leadingAnchor),
hosting.view.trailingAnchor.constraint(equalTo: uiScrollView.trailingAnchor),
hosting.view.topAnchor.constraint(equalTo: uiScrollView.contentLayoutGuide.topAnchor, constant: 0),
hosting.view.bottomAnchor.constraint(equalTo: uiScrollView.contentLayoutGuide.bottomAnchor, constant: 0),
hosting.view.widthAnchor.constraint(equalTo: uiScrollView.widthAnchor)
]
uiScrollView.addConstraints(constraints)
}
func makeCoordinator() -> Coordinator {
Coordinator(legacyScrollView: self)
}
func makeUIView(context: Context) -> UIScrollView {
uiScrollView.refreshControl = UIRefreshControl()
uiScrollView.refreshControl?.addTarget(context.coordinator, action:
#selector(Coordinator.handleRefreshControl), for: .valueChanged)
return uiScrollView
}
func updateUIView(_ uiView: UIScrollView, context: Context) {}
class Coordinator: NSObject {
let legacyScrollView: HomeScrollView
init(legacyScrollView: HomeScrollView) {
self.legacyScrollView = legacyScrollView
}
#objc func handleRefreshControl(sender: UIRefreshControl) {
refreshData()
}
}
}
//SwiftUi inside view's body
var body: some View {
VStack {
HomeScrollView() {
ViewOne(data: modelDataOne)
ViewTwo(data: modelDataTwo)
ViewThree(data: modelDataThree)
...
}
}
}

Swift: Make the background image of UITableViewController embedded in Navigation Controller fill the entire screen

I managed to create translucent and rounded UITableViewCells in a UITableViewController that is embedded inside a Navigation Controller with this line of code in viewDidLoad():
tableView.backgroundView = UIImageView(image: UIImage(named: "nightTokyo"))
But I want the background image to fill the entire phone screen. I changed the code (and only this line of code) to:
navigationController?.view = UIImageView(image: UIImage(named: "nightTokyo"))
Now the background image fills up the entire phone screen, but my table and even the iPhone's time and battery indicator icons are missing.
What I want is for the background image to fill the entire screen, but the tableView, its cells, the iPhone time, battery level icon, etc. to remain displayed.
navigationController?.setNavigationBarHidden(true, animated: true)
Here is what I did which worked for me using Swift 5, XCode 12.
Step 1 (Optional) - Create a custom UINavigationController class
class CustomNavigationController: UINavigationController {
override func viewWillAppear(_ animated: Bool) {
super.viewWillAppear(animated)
navigationBar.isTranslucent = true
}
Replace your UINavigationController with this UINavigationController subclass. I mark this as optional as this is based on preference, if you do not set this, your navigation bar will be opaque and you cannot see what's beneath it.
Setting the navigationBar.isTranslucent = true allows you to see the background beneath it which is what I like. A subclass is also optional but you might need to make other updates to your nav bar so I always like to make this a subclass.
Step 2 - Set up your background view constraints
class CustomViewController: UIViewController {
// your background view
let bgImageView: UIImageView = {
let bgImageView = UIImageView()
bgImageView.image = UIImage(named: "gradient_background")
bgImageView.contentMode = .scaleAspectFill
return bgImageView
}()
// Get the height of the nav bar and the status bar so you
// know how far up your background needs to go
var topBarHeight: CGFloat {
var top = self.navigationController?.navigationBar.frame.height ?? 0.0
if #available(iOS 13.0, *) {
top += UIApplication.shared.windows.first?.windowScene?.statusBarManager?.statusBarFrame.height ?? 0
} else {
top += UIApplication.shared.statusBarFrame.height
}
return top
}
var isLayoutConfigured = false
override func viewWillAppear(_ animated: Bool) {
super.viewWillAppear(animated)
title = "Site Visit"
// you only want to do this once
if !isLayoutConfigured() {
isLayoutConfigured = true
configBackground()
}
}
private func configBackground() {
view.addSubview(bgImageView)
configureBackgroundConstraints()
}
// Set up your constraints, main one here is the top constraint
private func configureBackgroundConstraints() {
bgImageView.translatesAutoresizingMaskIntoConstraints = false
bgImageView.topAnchor.constraint(equalTo: view.safeAreaLayoutGuide.topAnchor,
constant: -topBarHeight).isActive = true
bgImageView.leadingAnchor.constraint(equalTo: view.safeAreaLayoutGuide.leadingAnchor,
constant: 0).isActive = true
bgImageView.bottomAnchor.constraint(equalTo: view.safeAreaLayoutGuide.bottomAnchor,
constant: 0).isActive = true
bgImageView.trailingAnchor.constraint(equalTo: view.safeAreaLayoutGuide.trailingAnchor,
constant: 0).isActive = true
view.layoutIfNeeded()
}
Before setting constraints:
After setting above constraints:

SwiftUI View and UIHostingController in UIScrollView breaks scrolling

When I add a UIHostingController which contains a SwiftUI view as a childView, and then place that childView inside a UIScrollView, scrolling breaks.
Here I have my View
struct TestHeightView: View {
let color: UIColor
var body: some View {
VStack {
Text("THIS IS MY TEST")
.frame(height: 90)
}
.fixedSize(horizontal: false, vertical: true)
.background(Color(color))
.edgesIgnoringSafeArea(.all)
}
}
Then I have a UIViewController with a UIScrollView as the subView. Inside the UIScrollView there is a UIStackView that is correctly setup to allow loading UIViews and scrolling through them if the stack height becomes great enough. This works. If I were to load in 40 UILabels, it would scroll through them perfectly.
The problem arises when I add a plain old UIView, and then add a UIHostingController inside that container. I do so like this:
let container = UIView()
container.backgroundColor = color.0
stackView.insertArrangedSubview(container, at: 0)
let test = TestHeightView(color: color.1)
let vc = UIHostingController(rootView: test)
vc.view.backgroundColor = .clear
add(child: vc, in: container)
func add(child: UIViewController, in container: UIView) {
addChild(child)
container.addSubview(child.view)
child.view.translatesAutoresizingMaskIntoConstraints = false
child.view.topAnchor.constraint(equalTo: container.topAnchor, constant: 0).isActive = true
child.view.bottomAnchor.constraint(equalTo: container.bottomAnchor, constant: 0).isActive = true
child.view.leadingAnchor.constraint(equalTo: container.leadingAnchor, constant: 0).isActive = true
child.view.trailingAnchor.constraint(equalTo: container.trailingAnchor, constant: 0).isActive = true
child.didMove(toParent: self)
}
In my example I added 3 of these containerViews/UIHostingController and then one UIView (green) to demonstrate what is happening.
You can see that as I scroll, all views are suspended as a gap is formed. What is happening is that the containing UIView (light color) is expanding its height. Once the height reaches a certain value, scrolling continues as normal until the next container/UIHostingController reaches the top and it begins again.
I have worked on several different solutions
.edgesIgnoringSafeArea(.all)
Does do something. I included it in my example because without it, the problem is exactly the same only more jarring and harder to explain using a video. Basically the same thing happens but without any animation, it just appears that the UIScrollView has stopped working, and then it works again
Edit:
I added another UIViewController just to make sure it wasn't children in general causing the issue. Nope. Only UIHostingControllers do this. Something in SwiftUI
Unbelievably this is the only answer I can come up with:
I found it on Twitter here https://twitter.com/b3ll/status/1193747288302075906?s=20 by Adam Bell
class EMHostingController<Content> : UIHostingController<Content> where Content : View {
func fixedSafeAreaInsets() {
guard let _class = view?.classForCoder else { return }
let safeAreaInsets: #convention(block) (AnyObject) -> UIEdgeInsets = { (sself : AnyObject!) -> UIEdgeInsets in
return .zero
}
guard let method = class_getInstanceMethod(_class.self, #selector(getter: UIView.safeAreaInsets)) else { return }
class_replaceMethod(_class, #selector(getter: UIView.safeAreaInsets), imp_implementationWithBlock(safeAreaInsets), method_getTypeEncoding(method))
let safeAreaLayoutGuide: #convention(block) (AnyObject) ->UILayoutGuide? = { (sself: AnyObject!) -> UILayoutGuide? in
return nil
}
guard let method2 = class_getInstanceMethod(_class.self, #selector(getter: UIView.safeAreaLayoutGuide)) else { return }
class_replaceMethod(_class, #selector(getter: UIView.safeAreaLayoutGuide), imp_implementationWithBlock(safeAreaLayoutGuide), method_getTypeEncoding(method2))
}
override var prefersStatusBarHidden: Bool {
return true
}
}
Had the same issue recently, also confirm that safe area insets are breaking the scrolling. My fix on iOS 14+ with the ignoresSafeArea modifier:
public var body: some View {
if #available(iOS 14.0, *) {
contentView
.ignoresSafeArea()
} else {
contentView
}
}
I had a very similar issue and found a fix by adding the following to my UIHostingController subclass:
override func viewDidLoad() {
super.viewDidLoad()
edgesForExtendedLayout = []
}

Remove any view from any where e.g from window

I have 2 views on the screen, one is overlayView at the bottom and introView at the top of that overlayView. When I tap(tapToContinueAction) on the screen they should both hide or remove themselves.
extension UIView {
....
func hideView(view: UIView, hidden: Bool) {
UIView.transition(with: view, duration: 0.5, options: .transitionCrossDissolve, animations: {
view.isHidden = hidden
})
}
}
class IntroScreen
#IBAction func tapToContinueAction(_ sender: UITapGestureRecognizer) {
self.hideView(view: self, hidden: true)
}
--
class OverlayView : UiView {
...
}
In current situation i can hide introScreen only and i dont know how the other class's action can effect the overlayView at the same time and hide that view as well. Any idea?
You have two different classes for your views. Make an extension of your window to remove your specific views just like I have made removeOverlay and removeIntroView both these computed properties will go and search in subviews list of window and check each view with their type and remove them. Thats how you can remove any view form any where.
class OverLayView: UIView {}
class IntroView: UIView {
#IBAction func didTapYourCustomButton(sender: UIButton) {
let window = (UIApplication.shared.delegate as! AppDelegate).window!
window.removeOverlay
window.removeIntroView
}
}
extension UIWindow {
var removeOverlay: Void {
for subview in self.subviews {
if subview is OverLayView {
subview.removeFromSuperview()// here you are removing the view.
subview.hidden = true// you can hide the view using this
}
}
}
var removeIntroView: Void {
for subview in self.subviews {
if subview is IntroView {
subview.removeFromSuperview()// here you are removing the view.
subview.hidden = true// you can hide the view using this
}
}
}
}

Remove Collection view bounce issue when using pull to refresh

I have one collection view configured as follow
superCollectionView!.alwaysBounceHorizontal = false
superCollectionView!.alwaysBounceVertical = false
if #available(iOS 10.0, *) {
superCollectionView!.refreshControl = refreshControl
} else {
superCollectionView!.backgroundView = refreshControl
}
but bounce effect is still there.
I want to remove bounce from bottom...
If you want to remove bouncing only from the bottom (For letting the refreshControl to be available), I'd suggest to handle it in scroll​View​Did​Scroll:​ method to check if the scroll view contentOffset.y has been reached to bottom of the scroll view (logically, it is the content size of the scroll view minus the height of the visible frame of the scroll view), as follows:
Solution:
func scrollViewDidScroll(_ scrollView: UIScrollView) {
if scrollView.contentOffset.y >= scrollView.contentSize.height - scrollView.frame.size.height {
scrollView.setContentOffset(CGPoint(x: scrollView.contentOffset.x, y: scrollView.contentSize.height - scrollView.frame.size.height), animated: false)
}
}
Output:
After implementing scroll​View​Did​Scroll as mentioned above, it should be behaves like:
Also:
What about achieving the opposite?
Referring to the above description, preventing the top bouncing would be:
func scrollViewDidScroll(_ scrollView: UIScrollView) {
if scrollView.contentOffset.y < 0 {
scrollView.setContentOffset(CGPoint(x: scrollView.contentOffset.x, y: 0), animated: false)
}
}