SwiftUI - Animate View expansion (show / hide) - ios

Question

I have a View that contains a HStack and a DatePicker. When you tap on the HStack, the DatePicker is shown / hidden. I want to animate this action like the animation of Starts and Ends row in iOS Calendar's New Event View.
struct TimePicker: View {
#Binding var startTime: Date
#State private var isDatePickerVisible: Bool = false
var body: some View {
VStack(alignment: .center) {
HStack {
ListItemView(icon: "start-time",
leadingText: "Start Time",
trailingText: startTime.stringTime())
}
.onTapGesture {
withAnimation {
self.isDatePickerVisible.toggle()
}
}
Group {
if isDatePickerVisible {
DatePicker("", selection: $startTime, displayedComponents: [.hourAndMinute])
.datePickerStyle(WheelDatePickerStyle())
}
}
.background(Color.red)
.modifier(AnimatingCellHeight(height: isDatePickerVisible ? 300 : 0))
}
}
}
I have used the following code for animation. It almost works. The only problem is that HStack jumps. And I can not fix it.
https://stackoverflow.com/a/60873883/8292178
struct AnimatingCellHeight: AnimatableModifier {
var height: CGFloat = 0
var animatableData: CGFloat {
get { height }
set { height = newValue }
}
func body(content: Content) -> some View {
content.frame(height: height)
}
}
How to fix this issue? How to animate visibility of the DatePicker?

Answer 1

It's simple, you don't need extra ViewModifier
struct TimePicker: View {
#Binding var startTime: Date
#State private var isDatePickerVisible: Bool = false
var body: some View {
VStack(alignment: .center) {
HStack {
ListItemView(icon: "start-time"
, leadingText: "Start Time"
, trailingText: startTime.stringTime())
}.onTapGesture {
isDatePickerVisible.toggle()
}
if isDatePickerVisible {
DatePicker(""
, selection: $model.startTime
, displayedComponents: [.hourAndMinute]
).datePickerStyle(WheelDatePickerStyle())
}
}.animation(.spring())
}
}