Memory leak in TabView with PageTabViewStyle - ios

Question

I'm using a tab view using the UIPageViewController behaviour. So I defined the following model:
class WalktroughModel: Identifiable, ObservableObject {
let id: UUID = UUID()
let imageName: String
let title: String
init(imageName: String, title: String) {
self.imageName = imageName
self.title = title
}
}
Now I use this swiftUI view as a child view of tab view:
struct WalktroughAsset: View {
#StateObject var asset: WalktroughModel
var body: some View {
Image(asset.imageName)
.resizable()
.overlay(Color.black.opacity(0.43))
.overlay(
VStack{
Spacer()
Text(asset.title)
.foregroundColor(.white)
.font(.custom("OpenSans-regular", size: 22.0))
}
.padding(.bottom, 64)
)
}
}
In my content view I have the following:
struct ContentView: View {
var thumbs: [WalktroughModel] = [WalktroughModel(imageName: "splash-1", title: "Concepto 1"), WalktroughModel(imageName: "splash-2", title: "Concepto 2"), WalktroughModel(imageName: "splash-3", title: "Concepto 3")]
var body: some View {
ZStack {
Color.black.overlay(TabView{
ForEach(thumbs) {
image in
WalktroughAsset(asset: image)
}
}
.tabViewStyle(PageTabViewStyle())
.padding([.bottom, .top], 32)
)
}
.edgesIgnoringSafeArea(/*#START_MENU_TOKEN#*/.all/*#END_MENU_TOKEN#*/)
}
}
Now, when I build and run the memory jumps 80 mb to 160 mb when I swipe to the other view and jumps to 230 mb when I swipe to the third view. What could be happen?
Best Regards

Answer 1

This code fixes a memory leak for me
struct TabViewWrapper<Content: View, Selection: Hashable>: View {
#Binding var selection: Selection
#ViewBuilder let content: () -> Content
var body: some View {
TabView(selection: $selection, content: content)
}
}
Replace TabView(selection:) to TabViewWrapper(selection:)
TabViewWrapper(selection: $selection) {
tabContent
}
.tabViewStyle(PageTabViewStyle(indexDisplayMode: .never))
This bug is presented when you use custom view with args

Answer 2

Similar issue on iOS 15 (Tested on 15.2)
Memory use for the below SwiftUI app will continuously increase over time. The app is simply showing a TabView in a full screen cover, and has a timer that refreshes a countdown every second. If I display a simple text element instead of the TabView, the memory use will behave properly. I submitted a feedback to Apple.
import SwiftUI
class ContentView_manager : ObservableObject {
var view_timer: Timer?
#Published var countdown_txt: String?
func startTimer(){
if self.view_timer == nil {
self.view_timer = Timer(fireAt: Date(), interval: 1, target: self, selector: #selector(self.timer_action), userInfo: nil, repeats: true)
RunLoop.current.add(self.view_timer!, forMode: RunLoop.Mode.common)
}
}
func stopTimer(){
if self.view_timer != nil {
self.view_timer?.invalidate()
self.view_timer = nil
}
}
#objc
func timer_action(){
//update number of seconds until January 2023
print("Timer Action")
self.countdown_txt = String(DateInterval(start: Date(), end: Date(timeIntervalSince1970: 1672527600)).duration)
}
}
#main
struct debugApp: App {
var body: some Scene {
WindowGroup {
ContentView(view_manager:ContentView_manager())
}
}
}
struct ContentView : View {
#ObservedObject var view_manager : ContentView_manager
#State var show_cover : Bool = false
var body: some View {
VStack{
Button(action: {
self.show_cover = true
}, label: {Text("Show screen cover with TabView")})
}
.fullScreenCover(isPresented: self.$show_cover){ScreenCover(view_manager: view_manager)}
}
}
struct ScreenCover: View {
#ObservedObject var view_manager : ContentView_manager
var body: some View {
tab(txt:view_manager.countdown_txt)
.onAppear(perform: {
view_manager.startTimer()
})
.onDisappear(perform: {
view_manager.stopTimer()
})
}
}
struct tab: View {
var txt: String?
var body: some View {
TabView{
Text("First Tab")
.tabItem {
Image(systemName: "1.square.fill")
Text("First")
}
Text("Next year in \(txt ?? "") seconds!")
.tabItem {
Image(systemName: "2.square.fill")
Text("Second")
}
Text("Third tab")
.tabItem {
Image(systemName: "3.square.fill")
Text("Third")
}
}
.tabViewStyle(PageTabViewStyle())
}
}