I'm trying to make a quiz app using SwiftUI. Since I am doing mobile programming for the first time, I am inexperienced and I may have basic mistakes. I keep the questions that I will use in app in a CSV file. I am reading this CSV file with a foreach loop, but all questions are loaded on the screen because the loop is expected to end in the view section. What I want is for the foreach loop to go to the next iteration only when the button is clicked.
//
// QuestionView.swift
// csvQuestions
//
//
import SwiftUI
struct QuestionView: View {
var brandGradient = Gradient(colors: \[Color (.systemPurple), Color(.systemIndigo)\])
#State var Questionx:\[Question\]
var body: some View {
ZStack{
//ARKA PLAN
Image("Image")
.resizable()
.scaledToFill()
.frame(width: UIScreen.main.bounds.width*1,height: UIScreen.main.bounds.height*1)
VStack{
RoundedRectangle(cornerRadius: 20)
.fill(LinearGradient(colors: \[.white,.yellow\], startPoint: .top, endPoint: .bottom))
.frame(width: UIScreen.main.bounds.width*0.9,height: UIScreen.main.bounds.height*0.7)
.padding(80)
.opacity(0.85)
Spacer()
}
VStack(){
ForEach(Questionx){
question in
Text(question.detail)
.font(.callout)
.fontWeight(.semibold)
.multilineTextAlignment(.center)
.fontWidth(.standard)
.frame(width:UIScreen.main.bounds.width*0.9,height: UIScreen.main.bounds.height*0.1)
.offset(y:115)
Spacer()
ForEach (optionsGenerator(day: String(question.date), year: String(question.year)),id:.self) { i in
Button {
if ((question.date) == "\(i[0]) \(i[1])") && (String(question.year) == i[2])
{
print ("true")
}
else {
print ("false")
}
} label: {
Text ("(i\[0\]) " + String(i\[1\]) + " " + i\[2\])
.frame(width: UIScreen.main.bounds.width*0.75,height:UIScreen.main.bounds.height*0.075)
.foregroundColor (.white)
.background (RadialGradient (gradient: brandGradient, center: .center, startRadius: 25,
endRadius: 120))
.clipShape (Capsule())
}
}
}
Spacer()
}.frame(width: UIScreen.main.bounds.width*1,height: UIScreen.main.bounds.height*1)
}
}
}
struct QuestionView_Previews: PreviewProvider {
static var previews: some View {
QuestionView(Questionx: loadCSData())
}
}
I looked at the development of similar applications on YouTube but I could not find a solution. I also tried to set up the loop in different ways but with no results.
When I add multiple line of CSV file:
When I add only a single line of CSV file, everything looks like what I want:
I have a scenario where some text within an HStack may need to be multiple lines. I would like for the text to extend into the next line so a user would see 2 lines both left-aligned.
Here is some base setup in my View:
VStack(alignment: .center) {
HStack(spacing: 4) {
HStack(spacing: 4) {
Text("display name")
Image("display image").resizable().frame(width: 10, height: 10, alignment: .center)
}
Text("blah blah blah") // This text can extend to more than 1 line...
.lineLimit(nil) // so the text will be more than 1 line...
.frame(maxWidth: .infinity, alignment: .leading)
.fixedSize(horizontal: false, vertical: true)
Spacer()
}
.padding(EdgeInsets(top: 32, leading: 0, bottom: 0, trailing: 16))
Spacer()
// more stuff here
}
So what happens here is that my text does extend to more than one line, but it stays within its own little box, it doesn't move into a whole new line so it'll be under the first text within this HStack.
Update:
I ran this code in a blank project. Here is a screenshot for a visual example. It is not displaying how I want it to.
The goal is to keep it aligned and then move the second line below to start where the display name starts.
I have a list of entries that consist of multiple columns of UI with all except the first free to be uniquely sized horizontally (i.e. they’re as short/long as their content demands). I know with the first consistently sized column I can set a frame modifier width to achieve this, but I was hoping there is a better and more flexible way to get the desired behaviour. The reason being I don’t believe the solution is optimised to consider the user’s display size nor the actual max content width of the columns. That is, the width set will either not be wide enough when the display size is set to the largest, or, if it is, then it will be unnecessarily wide on a smaller/regular display size.
This is my current best attempt:
GeometryReader { geometry in
VStack {
HStack {
HStack {
Text("9am")
Image(systemName: "cloud.drizzle").font(Font.title2)
.offset(y: 4)
}.padding(.all)
.background(Color.blue.opacity(0.2))
.cornerRadius(16)
VStack {
HStack {
Text("Summary")
.padding(.trailing, 4)
.background(Color.white)
.layoutPriority(1)
VStack {
Spacer()
Divider()
Spacer()
}
VStack {
Text("12°")
Text("25%")
.foregroundColor(Color.black)
.background(Color.white)
}.offset(y: -6)
Spacer()
}.frame(width: geometry.size.width/1.5)
}
Spacer()
}
HStack {
HStack {
Text("10am")
.customFont(.subheadline)
Image(systemName: "cloud.drizzle").font(Font.title2)
.offset(y: 4)
.opacity(0)
}
.padding(.horizontal)
.padding(.vertical,4)
.background(Color.blue.opacity(0.2))
.cornerRadius(16)
VStack {
HStack {
ZStack {
Text("Mostly cloudy")
.customFont(.body)
.padding(.trailing, 4)
.background(Color.white)
.opacity(0)
VStack {
Spacer()
Divider()
Spacer()
}
}
VStack {
Text("13°")
Text("25%")
.foregroundColor(Color.black)
.background(Color.white)
}.offset(y: -6)
Spacer()
}.frame(width: geometry.size.width/1.75)
}
Spacer()
}
}
}
For me, this looks like:
As you can tell, 10 am is slightly wider than 9 am. To keep them as closely sized as possible, I’m including a cloud icon in it too, albeit with zero opacity. Ideally, 10 am would be sized the same as 9 am without needing a transparent cloud icon. More generally speaking, what would make sense is the widest HStack in this column is identified and then whatever its width is will be applied to all other columns. Keep in mind, my code above is static for demo purposes. It will be a view that is rendered iterating through a collection of rows.
You can use dynamic frame modifiers, such as frame(.maxWidth: .infinity) modifier to extend views so that they fill up the entire frame, even if the frame is dynamic. Here is an example that should help you get going:
struct CustomContent: View {
var body: some View {
VStack {
VStack {
CustomRow(timeText: "9am", systemIcon: "cloud.drizzle", centerText: "Summary", temperature: "12°", percent: "25%")
CustomRow(timeText: "10am", systemIcon: nil, centerText: nil, temperature: "13°", percent: "25%")
}
VStack {
CustomRow(timeText: "9am", systemIcon: "cloud.drizzle", centerText: "Summary", temperature: "12°", percent: "25%")
CustomRow(timeText: "10am", systemIcon: nil, centerText: nil, temperature: "13°", percent: "25%")
}
.frame(width: 300)
}
}
}
struct CustomContent_Previews: PreviewProvider {
static var previews: some View {
CustomContent()
}
}
struct CustomRow: View {
let timeText: String
let systemIcon: String?
let centerText: String?
let temperature: String
let percent: String
var body: some View {
HStack {
//Left column
HStack(alignment: .center) {
Text(timeText)
if let icon = systemIcon {
Image(systemName: icon)
.font(.title2)
}
}
.padding(.all)
.frame(width: 105, height: 60)
.background(Color.blue.opacity(0.2))
.cornerRadius(16)
// Center column
ZStack(alignment: .leading) {
Capsule()
.fill(Color.black.opacity(0.3))
.frame(height: 0.5)
if let text = centerText {
Text(text)
.lineLimit(1)
.background(Color.white)
}
}
// Right column
VStack {
Text(temperature)
Text(percent)
.foregroundColor(Color.black)
}
}
}
}
Guided by https://www.wooji-juice.com/blog/stupid-swiftui-tricks-equal-sizes.html, I accomplished this.
This is the piece of UI I want to make sure is horizontally sized equally across all rows with the width set to whatever is the highest:
HStack {
VStack {
Spacer()
Text("9am")
Spacer()
}
}.frame(minWidth: self.maximumSubViewWidth)
.overlay(DetermineWidth())
The stack the above is contained in has an OnPreferenceChange modifier:
.onPreferenceChange(DetermineWidth.Key.self) {
if $0 > maximumSubViewWidth {
maximumSubViewWidth = $0
}
}
The magic happens here:
struct MaximumWidthPreferenceKey: PreferenceKey
{
static var defaultValue: CGFloat = 0
static func reduce(value: inout CGFloat, nextValue: () -> CGFloat)
{
value = max(value, nextValue())
}
}
struct DetermineWidth: View
{
typealias Key = MaximumWidthPreferenceKey
var body: some View
{
GeometryReader
{
proxy in
Color.clear
.anchorPreference(key: Key.self, value: .bounds)
{
anchor in proxy[anchor].size.width
}
}
}
}
The link at the top best describes each’s purpose.
MaximumWidthPreferenceKey
This defines a new key, sets the default to zero, and as new values get added, takes the widest
DetermineWidth
This view is just an empty (Color.clear) background, but with our new preference set to its width. We’ll get back to that clear background part in a moment, but first: there are several ways to set preferences, here, we’re using anchorPreference. Why?
Well, anchorPreference has “No Overview Available” so I don’t actually have a good answer for that, other than it seems to be more reliable in practice. Yeah, cargo-cult code. Whee! I have a hunch that, what with it taking a block and all, SwiftUI can re-run that block to get an updated value when there are changes that affect layout.
Another hope I have is that this stuff will get better documented, so that we can better understand how these different types are intended to be used and new SwiftUI developers can get on board without spending all their time on Stack Overflow or reading blog posts like this one.
Anyway, an anchor is a token that represents a dimension or location in a view, but it doesn’t give you the value directly, you have to cash it in with a GeometryProxy to get the actual value, so, that’s what we did — to get the value, you subscript a proxy with it, so proxy[anchor].size.width gets us what we want, when anchor is .bounds (which is the value we passed in to the anchorPreference call). It’s kind of twisted, but it gets the job done.
maximumSubViewWidth is a binding variable passed in from the parent view to ensure the maximumSubViewWidth each subview refers to is always the the up-to-date maximum.
ForEach(self.items) { item, in
ItemSubview(maximumSubViewWidth: $maximumSubViewWidth, item: item)
}
The one issue with this was there was an undesired subtle but still noticeable animation on the entire row with any UI that gets resized to the max width. What I did to work around this is add an animation modifier to the parent container that’s nil to start with that switches back to .default after an explicit trigger.
.animation(self.initialised ? .default : nil)
I set self.initialised to be true after the user explicitly interacts with the row (In my case, they tap on a row to expand to show additional info) – this ensured the initial animation doesn't incorrectly happen but animations go back to normal after that. My original attempt toggled initialised's state in the .onAppear modifier so that the change is automatic but that didn't work because I’m assuming resizing can occur after the initial appearance.
The other thing to note (which possibly suggests although this solution works that it isn't the best method) is I'm seeing this message in the console repeated for either every item, or just the ones that needed to be resized (unclear but the total number of warnings = number of items):
Bound preference MaximumWidthPreferenceKey tried to update multiple
times per frame.
If anyone can think of a way to achieve the above whilst avoiding this warning then great!
UPDATE: I figured the above out.
It’s actually an important change because without addressing this I was seeing the column keep getting wider on subsequent visits to the screen.
The view has a new widthDetermined #State variable that’s set to false, and becomes true inside .onAppeared.
I then only determine the width for the view IF widthDetermined is false i.e. not set. I do this by using the conditional modifier proposed at https://fivestars.blog/swiftui/conditional-modifiers.html:
func `if`<Content: View>(_ conditional: Bool, content: (Self) -> Content) -> TupleView<(Self?, Content?)> {
if conditional { return TupleView((nil, content(self))) }
else { return TupleView((self, nil)) }
}
and in the view:
.if(!self.widthDetermined) {
$0.overlay(DetermineWidth())
}
I had similar issue. My text in one of the label in a row was varying from 2 characters to 20 characters. It messes up the horizontal alignment as you have seen. I was looking to make this column in row as fixed width. I came up with something very simple. And it worked for me.
var body: some View { // view for each row in list
VStack(){
HStack {
Text(wire.labelValueDate)
.
.
.foregroundColor(wire.labelColor)
.fixedSize(horizontal: true, vertical: false)
.frame(width: 110.0, alignment: .trailing)
}
}
}
I need to have back button which looks like the one displayed on any App's page in Apple App Store, having banner image. See image below:
I have tried finding any possible system icon image name as guided here:
https://stackoverflow.com/a/58900114/1152014
But couldn't find any appropriate one. Please guide.
The system icon image name is chevron.left.circle.fill (the one with fill color) and chevron.left.circle (the one without fill color)
By default the fill color is black, which you can change using the foreground color option.
import SwiftUI
struct ContentView: View {
var body: some View {
List {
Image(systemName: "chevron.left.circle.fill")
.resizable()
.frame(width: 50, height: 50, alignment: .center)
.listRowBackground(Color.green)
Text("")
Image(systemName: "chevron.left.circle")
.resizable()
.frame(width: 50, height: 50, alignment: .center)
.listRowBackground(Color.green)
}
.foregroundColor(.white)
}
}
I am working with a list in SwiftUI, I am attempting to recreate a system I had with TableView whereby a user can tap a cell and then a new view is presented with data relating to said cell. Now we have lists my code has changed to the following:
List {
ForEach(clients, id: \.id) { client in
VStack(alignment: .center) {
HStack{
Text(client.firstName ?? "Unknown" + " ")
.font(.system(size: 17))
.foregroundColor(Color.init(hex: "47535B"))
.fontWeight(.medium)
.multilineTextAlignment(.leading)
.padding(.leading)
Text(client.lastName ?? "Unknown")
.font(.system(size: 17))
.foregroundColor(Color.init(hex: "47535B"))
.fontWeight(.medium)
.multilineTextAlignment(.leading)
Spacer()
}
}
.frame(height: 50.0)
.background(Color.init(hex: "F6F6F6"))
.cornerRadius(7.0)
}
}
.padding(.horizontal, 3.0)
.padding(.vertical, 115.0)
.frame(minWidth: 0, maxWidth: .infinity, minHeight: 0, maxHeight: .infinity)
I realise I can use a NavigationLink and place the entire thing into a NavigationView but this functionality is not what I want, below is an image of my interface. What I am trying to achieve is when the user taps a cell it presents the data in the space on the right where it says "Select a client to view their profile". With the NavigationView setup I can only use the 2 default styles neither of which are suitable for me since I cannot customise where the navigation view gets placed. Is there a way I can register the same tap but have my own custom system for displaying the resulting data where I want in my interface? Perhaps I am wrong about NavigationView or maybe there is a way to have the NavigationView be positioned entirely outside of the view that contains the item list?
If you don't want to or aren't using use a NavigationView, then you likely have both the client list and the client detail in the same view somewhere. I would try adding #State private var selectedClient: Client? = nil to whatever view has both the list and the detail.
First, pass selectedClient as a binding to the list. Next, whenever one of the list items is tapped (achievable through .onTapGesture() or Button), Update selectedClient.
In your detail view, accept a bindable Client? parameter. If it's nil, then just show your current Text view. If it's not nil, then build the detail UI.
Hope this helps!