Reputation: 14168
I am using a UITextView
in a SwiftUI app in order to get a list of editable, multiline text fields based on this answer: How do I create a multiline TextField in SwiftUI?
I use the component in SwiftUI like this:
@State private var textHeight: CGFloat = 0
...
GrowingField(text: $subtask.text ?? "", height: $textHeight, changed:{
print("Save...")
})
.frame(height: textHeight)
The GrowingField is defined like this:
struct GrowingField: UIViewRepresentable {
@Binding var text: String
@Binding var height: CGFloat
var changed:(() -> Void)?
func makeUIView(context: Context) -> UITextView {
let textView = UITextView()
textView.delegate = context.coordinator
textView.isScrollEnabled = false
textView.backgroundColor = .orange //For debugging
//Set the font size and style...
textView.setContentCompressionResistancePriority(.defaultLow, for: .horizontal)
return textView
}
func updateUIView(_ uiView: UITextView, context: Context) {
if uiView.text != self.text{
uiView.text = self.text
}
recalculateHeight(textView: uiView, height: $height)
}
func recalculateHeight(textView: UITextView, height: Binding<CGFloat>) {
let newSize = textView.sizeThatFits(CGSize(width: textView.frame.size.width, height: CGFloat.greatestFiniteMagnitude))
if height.wrappedValue != newSize.height {
DispatchQueue.main.async {
height.wrappedValue = newSize.height
}
}
}
//Coordinator and UITextView delegates...
}
The problem I'm having is that sizeThatFits
calculates the correct height at first, then replaces it with an incorrect height. If I print
the newSize
inside recalculateHeight()
it goes like this when my view loads:
(63.0, 34.333333333333336) <!-- Right
(3.0, 143.33333333333334) <!-- Wrong
(3.0, 143.33333333333334) <!-- Wrong
I have no idea where the wrong size is coming from, and I don't know why the right one is replaced. This is how it looks with the height being way too big:
If I make a change to it, the recalculateHeight()
method gets called again via textViewDidChange()
and it rights itself:
This is really hacky, but if I put a timer in makeUIView()
, it fixes itself as well:
//Eww, gross...
Timer.scheduledTimer(withTimeInterval: 1.0, repeats: false) { _ in
recalculateHeight(view: textView, height: $height)
}
Any idea how I can determine where the incorrect sizeThatFits
value is coming from and how I can fix it?
Upvotes: 2
Views: 1040
Reputation: 14168
It took me a long time to arrive at a solution for this. It turns out the UITextView
sizing logic is good. It was a parent animation that presents my views that was causing updateUIView
to fire again with in-transition UITextView
size values.
By setting .animation(.none)
on the parent VStack
that holds all my text fields, it stopped the propagation of the animation and now it works. 🙂
Upvotes: 2