Adjust SwiftUI Component from UIKit - swiftui

Sometimes I any need to adjust the swiftUI component, so I dive into UIKit and adjust what I need, for example in the code below I adjust the table view appearance for a specific view, the problem is that effect to all the SwiftUI views the have table view so everything became a big mess, did there is some way to adjust the SwiftUI component for specific view without effect the same component in the other's views.
struct New_EditGroup: View {
init() {
let tableAppearance = UITableView.appearance()
tableAppearance.contentInset = UIEdgeInsets(top: 16, left: 0, bottom: 0, right: 0)
tableAppearance.sectionHeaderHeight = 1
tableAppearance.sectionFooterHeight = 16
}
var body: some View {
// ...

struct ContentView: View {
var body: some View {
NavigationView {
Form {
Section(header: Spacer().frame(height: 16)) {
ForEach(1..<10) { element in
Text("Element \(element)")
}
}
}
.navigationBarTitle("Main Menu", displayMode: .inline)
}
}
}

Related

How to get the height of a dynamic View in SwiftUI?

Working on a project where view are aligned like this
HeaderView
TabView
Views with each tab
List and other items in each view
Relevant code is
struct Home: View {
#StateObject var manageScrollPosition = ManageScrollPosition()
var body: some View {
GeometryReader { gReader in
ScrollView {
VStack {
EntityHeaderView(bottomViewPopupData: $bottomViewPopupData)
EntityTabView(manageScrollPosition: manageScrollPosition)
.frame(height: gReader.size.height)
}
.background(GeometryReader {
Color.clear.preference(key: ViewOffsetKey.self,
value: -$0.frame(in: .named("scroll")).origin.y)
})
.onPreferenceChange(ViewOffsetKey.self) {
if $0 == 238.0 {
manageScrollPosition.isScrollEnable = false
}
}
}
.coordinateSpace(name: "scroll")
.introspectScrollView { scrollView in
scrollView.bounces = manageScrollPosition.isScrollEnable
scrollView.isScrollEnabled = manageScrollPosition.isScrollEnable
}
}
}
I have to disable the scrolling of main scrollview once tab is reaches to top and enable the scrolling of list from child View.
Right now I'm able to achive this with static height of header View
if $0 == 238.0 {
manageScrollPosition.isScrollEnable = false
}
want to replace this static value with actual height of header or some other solution.
I'm new in SwiftUI, Very thank full for your solutiuon in advance.

Navigation + Tabview + Sheet broken in iOS 15

It looks like Navigation + TabView + Sheet is broken in iOS 15.
When I do this:
ContentView -> DetailView -> Bottom Sheet
When the bottom sheet comes up, the Detail view is automatically popped off the stack:
https://www.youtube.com/watch?v=gguLptAx0l4
I expect the Detail view to stay there even when the bottom sheet appears. Does anyone have any idea on why this happens and how to fix it?
Here is my sample code:
import Combine
import SwiftUI
import RealmSwift
struct ContentView: View {
var body: some View {
NavigationView {
TabView {
TabItemView(num: 1)
.tabItem {
Text("One")
}
TabItemView(num: 2)
.tabItem {
Text("Two")
}
}
}
}
}
struct TabItemView: View {
private let num: Int
init(num: Int) {
self.num = num
}
var body: some View {
NavigationLink(destination: DetailView(text: "Detail View \(num)")) {
Text("Go to Detail View")
}
}
}
struct DetailView: View {
#State private var showingSheet = false
private let text: String
init(text: String) {
self.text = text
}
var body: some View {
Button("Open Sheet") {
showingSheet.toggle()
}.sheet(isPresented: $showingSheet) {
Text("Sheet Text")
}
}
}
This works on iOS 14 btw
UPDATE 1:
Tried #Sebastian's suggestion of putting NavigationView inside of TabView. While this fixed the nav bug, it fundamentally changed the behavior (I don't want to show the tabs in DetailView).
Also tried his suggestion of using Introspect to set navigationController.hidesBottomBarWhenPushed = true on the NavigationLink destination, but that didn't do anything:
struct ContentView: View {
var body: some View {
TabView {
NavigationView {
TabItemView(num: 1)
}.tabItem {
Text("One")
}
NavigationView {
TabItemView(num: 2)
}.tabItem {
Text("Two")
}
}
}
}
struct TabItemView: View {
private let num: Int
init(num: Int) {
self.num = num
}
var body: some View {
NavigationLink(destination: DetailView(text: "Detail View \(num)").introspectNavigationController { navigationController in
navigationController.hidesBottomBarWhenPushed = true
}) {
Text("Go to Detail View")
}
}
}
struct DetailView: View {
#State private var showingSheet = false
private let text: String
init(text: String) {
self.text = text
}
var body: some View {
Button("Open Sheet") {
showingSheet.toggle()
}.sheet(isPresented: $showingSheet) {
Text("Sheet Text")
}
}
}
You need to flip how you nest TabView & NavigationView. Instead of nesting several TabView views inside a NavigationView, use the TabView as the parent component, with a NavigationView for each tab.
This is how the updated ContentView would look like:
struct ContentView: View {
var body: some View {
TabView {
NavigationView {
TabItemView(num: 1)
}
.tabItem {
Text("One")
}
NavigationView {
TabItemView(num: 2)
}
.tabItem {
Text("Two")
}
}
}
}
This makes sense and is more correct: The tabs should always be visible, but you want to show a different navigation stack with different content in each tab.
That it worked previously doesn't make it more correct - SwiftUI probably just changed its mind on dealing with unexpected situations. That, and the lack of error messages in these situations, is the downside of using a framework that tries to render anything you throw at it!
If the goal is specifically to hide the tabs when pushing a new view on a NavigationView (e.g., when tapping on a conversation in a messaging app), you have to use a different solution. Apple added the UIViewController.hidesBottomBarWhenPushed property to UIKit to support this specific use case.
This property is set on the UIViewController that, when presented, should not show a toolbar. In other words: Not the UINavigationController or the UITabBarController, but the child UIViewController that you push onto the UINavigationController.
This property is not supported in SwiftUI natively. You could set it using SwiftUI-Introspect, or simply write the navigation structure of your application using UIKit and write the views inside in SwiftUI, linking them using UIHostingViewController.

View resizing when hiding tab bar with Introspect in SwiftUI

I'm using Introspect to hide the tab bar on child navigation link pages. However, I've noticed some odd behavior when the app is backgrounded and then brought back to the foreground.
It seems like initially, the hidden tab bar is still taking up some space, but this disappears when cycling the app back to the foreground. I'm not sure if this is SwiftUI behavior or has to do with how I'm using Introspect / UIKit.
It's causing layout issues in my app, so I'd like to make the spacing consistent if possible.
Here's a minimal example that shows the behavior:
import SwiftUI
import Introspect
struct ContentView: View {
var body: some View {
TabView {
VStack {
Spacer()
Text("Hello, world!")
}
}
.border(Color.red)
.introspectTabBarController { tabBarController in
tabBarController.tabBar.isHidden = true
}
}
}
Here is the late answer. Basically add tabbar height to current view frame. And onDissappear restore view frame size
import SwiftUI
import Introspect
#State var uiTabarController: UITabBarController?
#State var tabBarFrame: CGRect?
struct ContentView: View {
var body: some View {
TabView {
VStack {
Spacer()
Text("Hello, world!")
}
}
.border(Color.red)
.introspectTabBarController { (UITabBarController) in
uiTabarController = UITabBarController
self.tabBarFrame = uiTabarController?.view.frame
uiTabarController?.tabBar.isHidden = true
uiTabarController?.view.frame = CGRect(x:0, y:0, width:tabBarFrame!.width, height:tabBarFrame!.height+UITabBarController.tabBar.frame.height);
}
.onDisappear {
if let frame = self.tabBarFrame {
self.uiTabarController?.tabBar.isHidden = false
uiTabarController?.view.frame = frame
}
}
}
}

How to create an SwiftUI animation effect from the Model?

I have a model object, which has a published property displayMode, which is updated asynchronously via events from the server.
class RoomState: NSObject, ObservableObject {
public enum DisplayMode: Int {
case modeA = 0
case modeB = 1
case modeC = 2
}
#Published var displayMode = DisplayMode.modeA
func processEventFromServer(newValue: DisplayMode) {
DispatchQueue.main.async {
self.displayMode = newValue
}
}
}
Then, I have a View, which displays this mode by placing some image in a certain location depending on the value.
struct RoomView: View {
#ObservedObject var state: RoomState
var body: some View {
VStack {
...
Image(systemName: "something")
.offset(x: state.displayMode.rawValue * 80, y:0)
}
}
}
This code works fine, but I want to animate the movement when the value changes. If I change the value in the code block inside the View, I can use withAnimation {..} to create an animation effect, but I am not able to figure out how to do it from the model.
This is the answer, thanks to #aheze. With .animation(), this Image view always animates when the state.displayMode changes.
struct RoomView: View {
#ObservedObject var state: RoomState
var body: some View {
VStack {
...
Image(systemName: "something")
.offset(x: state.displayMode.rawValue * 80, y:0)
.animation(.easeInOut)
}
}
}

SwiftUI How To Hide The Navigation Bar While Keeping The Back Button

So I'm trying to hide the navigationBar in a Details view in SwiftUI. I've technically gotten it to work by using an init() in a different view, but the issue is that it's making the navigationBar transparent for the whole app, which I only want it in one view. The reason I haven't used an init() in the DetailsView is because I have a variable that needs an input, so I wasn't sure how to do that! Here is the code for the initializer:
init() {
let navBarAppearance = UINavigationBar.appearance()
navBarAppearance.backgroundColor = .clear
navBarAppearance.barTintColor = .clear
navBarAppearance.tintColor = .black
navBarAppearance.setBackgroundImage(UIImage(), for: .default)
navBarAppearance.shadowImage = UIImage()
}
Here's What The Content View and Details View code is like with the init() inside the detailsView:
// ContentView //
struct ContentView: View {
var body: some View {
NavigationView {
List {
ForEach(0..<5) { i in
NavigationLink(destination: DetailsView(test: 1)) {
Text("DetailsView \(i)")
}
}
}
.listStyle(InsetGroupedListStyle())
.navigationBarTitle("Test App")
}
}
}
// DetailsView //
struct DetailsView: View {
var test: Int
var body: some View {
ScrollView {
Text("More Cool \(test)")
Text("Cool \(test)")
Text("Less Cool \(test)")
}
}
init(test: Int) {
self.test = 8
let navBarAppearance = UINavigationBar.appearance()
navBarAppearance.backgroundColor = .clear
navBarAppearance.barTintColor = .clear
navBarAppearance.tintColor = .black
navBarAppearance.setBackgroundImage(UIImage(), for: .default)
navBarAppearance.shadowImage = UIImage()
}
}
struct DetailsView_Previews: PreviewProvider {
static var previews: some View {
DetailsView(test: 8)
}
}
It's a heavily edited version of my code, but it shows the problem I have. With no variables needing to be passed in, the init() worked to remove the bar in only that view. However, with that variable input, not only does it change all the views to the "8" for the number, but it also doesn't even hide the navigationBar. I'm not sure if I'm just doing something wrong nor if this is even the right way to do it, but any help would be appreciated!
Also, on a side note, does anyone know how to hide the statusBar in iOS 14 with the NavigationView?
I think you try to use UIKit logic instead of the SwiftUI one. This is what I would do to hide the navigation bar with a back button on the top leading side of your view.
As for hiding the status bar, I would use .statusBar(hidden: true).
But it seems not to work on iOS14. It may be a bug... You can refer yourself to the Apple documentation on this topic.
struct DetailsView: View {
#Environment(\.presentationMode) var presentation
var test: Int
var body: some View {
ZStack(alignment: .topLeading) {
ScrollView {
Text("More Cool \(test)")
Text("Cool \(test)")
Text("Less Cool \(test)")
}
Button(action: { presentation.wrappedValue.dismiss() }) {
HStack {
Image(systemName: "chevron.left")
.foregroundColor(.blue)
.imageScale(.large)
Text("Back")
.font(.title3)
.foregroundColor(.blue)
}
}
.padding(.leading)
.padding(.top)
}
.navigationTitle(Text(""))
.navigationBarHidden(true)
.statusBar(hidden: true)
}
}