SwiftUI Create a Custom Segmented Control also in a ScrollView - ios

Question

Below is my code to create a standard segmented control.
struct ContentView: View {
#State private var favoriteColor = 0
var colors = ["Red", "Green", "Blue"]
var body: some View {
VStack {
Picker(selection: $favoriteColor, label: Text("What is your favorite color?")) {
ForEach(0..<colors.count) { index in
Text(self.colors[index]).tag(index)
}
}.pickerStyle(SegmentedPickerStyle())
Text("Value: \(colors[favoriteColor])")
}
}
}
My question is how could I modify it to have a customized segmented control where I can have the boarder rounded along with my own colors, as it was somewhat easy to do with UIKit? Has any one done this yet.
I prefect example is the Uber eats app, when you select a restaurant you can scroll to the particular portion of the menu by selecting an option in the customized segmented control.
Included are the elements I'm looking to have customized:
* UPDATE *
Image of the final design

Answer 1

Is this what you are looking for?
import SwiftUI
struct CustomSegmentedPickerView: View {
#State private var selectedIndex = 0
private var titles = ["Round Trip", "One Way", "Multi-City"]
private var colors = [Color.red, Color.green, Color.blue]
#State private var frames = Array<CGRect>(repeating: .zero, count: 3)
var body: some View {
VStack {
ZStack {
HStack(spacing: 10) {
ForEach(self.titles.indices, id: \.self) { index in
Button(action: { self.selectedIndex = index }) {
Text(self.titles[index])
}.padding(EdgeInsets(top: 16, leading: 20, bottom: 16, trailing: 20)).background(
GeometryReader { geo in
Color.clear.onAppear { self.setFrame(index: index, frame: geo.frame(in: .global)) }
}
)
}
}
.background(
Capsule().fill(
self.colors[self.selectedIndex].opacity(0.4))
.frame(width: self.frames[self.selectedIndex].width,
height: self.frames[self.selectedIndex].height, alignment: .topLeading)
.offset(x: self.frames[self.selectedIndex].minX - self.frames[0].minX)
, alignment: .leading
)
}
.animation(.default)
.background(Capsule().stroke(Color.gray, lineWidth: 3))
Picker(selection: self.$selectedIndex, label: Text("What is your favorite color?")) {
ForEach(0..<self.titles.count) { index in
Text(self.titles[index]).tag(index)
}
}.pickerStyle(SegmentedPickerStyle())
Text("Value: \(self.titles[self.selectedIndex])")
Spacer()
}
}
func setFrame(index: Int, frame: CGRect) {
self.frames[index] = frame
}
}
struct CustomSegmentedPickerView_Previews: PreviewProvider {
static var previews: some View {
CustomSegmentedPickerView()
}
}

Answer 2

If I'm following the question aright the starting point might be something like the code below. The styling, clearly, needs a bit of attention. This has a hard-wired width for segments. To be more flexible you'd need to use a Geometry Reader to measure what was available and divide up the space.
struct ContentView: View {
#State var selection = 0
var body: some View {
let item1 = SegmentItem(title: "Some Way", color: Color.blue, selectionIndex: 0)
let item2 = SegmentItem(title: "Round Zip", color: Color.red, selectionIndex: 1)
let item3 = SegmentItem(title: "Multi-City", color: Color.green, selectionIndex: 2)
return VStack() {
Spacer()
Text("Selected Item: \(selection)")
SegmentControl(selection: $selection, items: [item1, item2, item3])
Spacer()
}
}
}
struct SegmentControl : View {
#Binding var selection : Int
var items : [SegmentItem]
var body : some View {
let width : CGFloat = 110.0
return HStack(spacing: 5) {
ForEach (items, id: \.self) { item in
SegmentButton(text: item.title, width: width, color: item.color, selectionIndex: item.selectionIndex, selection: self.$selection)
}
}.font(.body)
.padding(5)
.background(Color.gray)
.cornerRadius(10.0)
}
}
struct SegmentButton : View {
var text : String
var width : CGFloat
var color : Color
var selectionIndex = 0
#Binding var selection : Int
var body : some View {
let label = Text(text)
.padding(5)
.frame(width: width)
.background(color).opacity(selection == selectionIndex ? 1.0 : 0.5)
.cornerRadius(10.0)
.foregroundColor(Color.white)
.font(Font.body.weight(selection == selectionIndex ? .bold : .regular))
return Button(action: { self.selection = self.selectionIndex }) { label }
}
}
struct SegmentItem : Hashable {
var title : String = ""
var color : Color = Color.white
var selectionIndex = 0
}
struct ContentView_Previews: PreviewProvider {
static var previews: some View {
ContentView()
}
}

Answer 3

None of the above solutions worked for me as the GeometryReader returns different values once placed in a Navigation View that throws off the positioning of the active indicator in the background. I found alternate solutions, but they only worked with fixed length menu strings. Perhaps there is a simple modification to make the above code contributions work, and if so, I would be eager to read it. If you're having the same issues I was, then this may work for you instead.
Thanks to inspiration from a Reddit user "End3r117" and this SwiftWithMajid article, https://swiftwithmajid.com/2020/01/15/the-magic-of-view-preferences-in-swiftui/, I was able to craft a solution. This works either inside or outside of a NavigationView and accepts menu items of various lengths.
struct SegmentMenuPicker: View {
var titles: [String]
var color: Color
#State private var selectedIndex = 0
#State private var frames = Array<CGRect>(repeating: .zero, count: 5)
var body: some View {
VStack {
ZStack {
HStack(spacing: 10) {
ForEach(self.titles.indices, id: \.self) { index in
Button(action: {
print("button\(index) pressed")
self.selectedIndex = index
}) {
Text(self.titles[index])
.foregroundColor(color)
.font(.footnote)
.fontWeight(.semibold)
}
.padding(EdgeInsets(top: 0, leading: 5, bottom: 0, trailing: 5))
.modifier(FrameModifier())
.onPreferenceChange(FramePreferenceKey.self) { self.frames[index] = $0 }
}
}
.background(
Rectangle()
.fill(self.color.opacity(0.4))
.frame(
width: self.frames[self.selectedIndex].width,
height: 2,
alignment: .topLeading)
.offset(x: self.frames[self.selectedIndex].minX - self.frames[0].minX, y: self.frames[self.selectedIndex].height)
, alignment: .leading
)
}
.padding(.bottom, 15)
.animation(.easeIn(duration: 0.2))
Text("Value: \(self.titles[self.selectedIndex])")
Spacer()
}
}
}
struct FramePreferenceKey: PreferenceKey {
static var defaultValue: CGRect = .zero
static func reduce(value: inout CGRect, nextValue: () -> CGRect) {
value = nextValue()
}
}
struct FrameModifier: ViewModifier {
private var sizeView: some View {
GeometryReader { geometry in
Color.clear.preference(key: FramePreferenceKey.self, value: geometry.frame(in: .global))
}
}
func body(content: Content) -> some View {
content.background(sizeView)
}
}
struct NewPicker_Previews: PreviewProvider {
static var previews: some View {
VStack {
SegmentMenuPicker(titles: ["SuperLongValue", "1", "2", "Medium", "AnotherSuper"], color: Color.blue)
NavigationView {
SegmentMenuPicker(titles: ["SuperLongValue", "1", "2", "Medium", "AnotherSuper"], color: Color.red)
}
}
}
}