I am struggling making an attempt to implement a PreferenceKey. I’ve learn numerous articles, so
clearly I am lacking one thing. onPreferenceChange stories as soon as at simulator startup however
not throughout scrolling. Scrolling updates the textual content within the TextEditor overlay, however the
offsetCGSize property is outwardly by no means up to date. Here is a simplified model
of the code:
struct SOView: View {
@State personal var firstText: String = "first"
@State personal var secondText: String = "second"
@State personal var thirdText: String = "third"
@State personal var offsetCGSize: CGSize = .zero
var physique: some View {
ScrollView {
VStack {
ForEach(0..<20) {index in
Textual content("Line quantity (index)")
}
Picture(systemName: "globe")
.imageScale(.giant)
.foregroundColor(.accentColor)
TextField("First", textual content: $firstText)
GeometryReader { teGeo in
TextEditor(textual content: $secondText)
.body(peak: 100)
.overlay(
RoundedRectangle(cornerRadius: 10).stroke(lineWidth: 2)
)
.overlay(
Textual content("(teGeo.body(in: .world).minY)")
)
.desire(key: OffsetPreferenceKey.self, worth: CGSize(width: 0, peak: teGeo.body(in: .world).minY))
}//geo
.body(peak: 100)
TextField("Third", textual content: $thirdText)
Textual content("TextEditor prime is (offsetCGSize.peak)")
}//v
.padding()
}//scroll
.onPreferenceChange(OffsetPreferenceKey.self) { worth in
offsetCGSize = worth
print("offsetCGSize is (offsetCGSize)")
}
}//physique
}//so view
personal struct OffsetPreferenceKey: PreferenceKey {
static var defaultValue: CGSize = CGSize.zero
static func cut back(worth: inout CGSize, nextValue: () -> CGSize) {
worth = nextValue()
}
}//off pref
Any steerage can be appreciated. Xcode 14.0.1, iOS 16
