SwiftUI: How to disable scrolling in List without disabling content - list

I have a list in SwiftUI declared as follows:
List {
Text("Test")
Text("Test)
...
Toggle(...)
}
I'd like to make this list unscrollable without using .disabled(true), as I'd like the toggle to be interactable. How can I accomplish this?

Put this below the list:
.onAppear {
UITableView.appearance().isScrollEnabled = false
}

Related

Cannot use instance member '' within property initializer OnAppear does not working as well

I am trying to create a LazyVGrid based on user selection in another view. As follows, the peoplelist and selectedpersonID are coming from other view.
I understand that I cannot use the "selectedpersons" during initializing of this view. I looked here(Cannot use instance member 'service' within property initializer; property initializers run before 'self' is available) to use onAppear() of the LazyVGrid.
It goes well during compiling and works ok if you select 1 person.
Once I selected 2 persons, I got a Fatal error that Index out of range at row.
struct Someview: View {
#ObservedObject var peoplelist : PersonList
let selectedpersonID : Set<UUID>?
#State private var days : [String] = Array(repeating: "0", count: selectedpersons.count * 5) //got first error here, during compiling
var body: some View {
VStack{
LazyVGrid(columns: columns) {
Text("")
ForEach(1..<6) { i in
Text("\(i)").bold()
}
ForEach(0..< selectedpersons.count , id: \.self) { row in
Text(selectedpersons[row].Name)
ForEach(0..<5) { col in
TextField("", text: $days[row * 5 + col])
}
}
}
.onAppear(){
days = Array(repeating: "0", count: selectedpersons.count * 5)}//no problem during compiling, but will have error when more than 1 person are selected.
.padding()
}
}
var selectedpersons: [Persons] {
return peoplelist.persons.filter {selectedpersonID!.contains($0.id)}
}
}
It seems to me that this OnAppear() is still slower than the content inside the LazyVGrid? So, the days is not changed quick enough for building the content insider the LazyVGrid?
Or did I make an error of the index in the array of days?
It's crashing because ForEach isn't a for loop its a View that needs to be supplied Identifiable data. If you're using indices, id: \self or data[index] then something has gone wrong. There are examples of how to use it correctly in the documentation.
Also onAppear is for performing a side-effect action when the UIView that SwiftUI manages appears, it isn't the correct place to set view data, the data should be already in the correct place when the View struct is init. Making custom Views is a good way to solve this.

Changing swipeActions dynamically in SwiftUI

I am trying to change the swipeAction from "Paid" to "UnPaid" based on payment status and somehow seems to be failing. Error: "The compiler is unable to type-check this expression in reasonable time; try breaking up the expression into distinct sub-expressions"
Appreciate any help
struct ContentView: View {
var data: [Data] = [data1, data2, data3, data4]
#State var swipeLabel = true
var body: some View {
let grouped = groupByDate(data)
List {
ForEach(Array(grouped.keys).sorted(by: >), id: \.self) { date in
let studentsDateWise = grouped[date]!
Section(header:Text(date, style: .date)) {
ForEach(studentsDateWise, id:\.self) { item in
HStack {
Text(item.name)
padding()
Text(item.date, style: .time)
if(item.paymentStatus == false) {
Image(systemName: "person.fill.questionmark")
.foregroundColor(Color.red)
} else {
Image(systemName: "banknote")
.foregroundColor(Color.green)
}
} // HStack ends here
.swipeActions() {
if(item.paymentStatus) {
Button("Paid"){}
} else {
Button("UnPaid"){}
}
}
} // ForEach ends here...
} // section ends here
} // ForEach ends here
} // List ends here
} // var ends here
}
The body func shouldn't do any grouping or sorting. You need to prepare your data first into properties and read from those in body, e.g. in an onAppear block. Also if your Data is a struct you can't use id: \.self you need to either specify a unique identifier property on the data id:\.myUniqueID or implement the Indentifiable protocol by either having an id property or an id getter that computes a unique identifier from other properties.
I would suggest separating all this code into small Views with a small body that only uses one or a two properties. Work from bottom up. Then eventually with one View works on an array of dates and another on an array of items that contains the small Views made earlier.
You should probably also learn that if and foreach in body are not like normal code, those are converted into special Views. Worth watching Apple's video Demystify SwiftUI to learn about structural identity.

SwiftUI Size to fit or word-wrap navigation title

I have a navigation title that is too large on some smaller devices.
I've read many ways to set the titleTextAttributes and largeTitleTextAttributes of the UINavigationBar.appearance() however when setting the paragraph style to word wrap, it seems to remove the standard ... clipping and have the text continue off the edge of the screen without wrapping:
init() {
let paragraphStyle = NSMutableParagraphStyle()
paragraphStyle.lineBreakMode = .byWordWrapping
UINavigationBar.appearance().largeTitleTextAttributes = [
.paragraphStyle: paragraphStyle
]
}
I want to maintain the SwiftUI behaviour where the title is shown as large text until the view is scrolled up and it moves to the navigation bar, so getting the .toolbar directly won't help.
I also don't want to just specify a smaller font as I only want it to shrink or wrap if necessary.
Has anyone managed to achieve this?
You can add this line on the initializer of the view where yo have the issue
UILabel.appearance(whenContainedInInstancesOf: [UINavigationBar.self]).adjustsFontSizeToFitWidth = true
Example:
struct YourView: View {
init() {
UILabel.appearance(whenContainedInInstancesOf: [UINavigationBar.self]).adjustsFontSizeToFitWidth = true
}
var body: some View {
NavigationView {
Text("Your content")
.navigationBarTitle("Very very large title to fit in screen")
}
}
}

What are the requirements for a free expandable List in SwiftUI?

Somewhere in my code I have this pretty standard list with sections:
var body: some View {
List {
ForEach(userData.groupedBookings) { group in
Section(header: Text(group.key)) {
ForEach(group.items) { booking in
LessonRow(booking: booking)
}
}
}
}
}
Somehow with this code the sections are expandable/collapsable, which makes me happy, but I don't know why.
I'm especially frustrated because I want to reproduce this behavior elsewhere with similar code and don't get the expand / collapse.
What are the requirement to automatically get this?
It is activated by sidebar list style (which in some conditions are considered as default), which you can use explicitly
List {
ForEach(userData.groupedBookings) { group in
Section(header: Text(group.key)) {
ForEach(group.items) { booking in
LessonRow(booking: booking)
}
}
}
}
.listStyle(SidebarListStyle())
as alternate you can use DisclosureGroup explicitly to have disclosure behavior for sections, like in https://stackoverflow.com/a/63228810/12299030

SwiftUI PickerView with working CallBack HOW?

Ok -
I want a picker view to pick one operator: "=","<",">"
This operator will be sent as a binding:
#Binding var op:String
My Picker:
Picker(selection: binding, label: Text("Query Type")) {
ForEach(0..<self.operators.count) { index in
Text(self.operators[index]).tag(index)
}
}.pickerStyle(SegmentedPickerStyle())
.padding()
Now My Binding with CallBack:
let binding = Binding<Int>(
get: {
return self.pickerSelection
},
set: {
//pickerSelection = $0
print("SETTTING: \($0)")
self.op = self.operators[self.pickerSelection]
self.queryCallback()
})
So, I can set the pickers perfectly. BUT, when I go back to edit my data, the picker never can choose the existing bound operator, say "<"
I put in the init an:
pickerSelection = operators.firstIndex(opValue)
However this will just start an infinite loop as pickerSelection is a #State variable
Anyone have a solution?
This is a method that works. It uses Combine to make an observable one can use to trigger the needed events. Also I see how useful Combine is with SwiftUI
https://stackoverflow.com/a/57519105/810300