floatingPanelState(_:) modifier breaks panel interactivity when used with FloatingPanelControllerDelegate methods #680
Description
First of all thank you so much for providing this great package. We have been using it in our app for years now, since it is the best solution for panels. We are refactoring our app to SwiftUI and now it's time to update screens with panels. Unfortunately, I faced some issue with this package.
Description
We use floatingPanelState(_:) to programmatically control state of panel but also we use FloatingPanelControllerDelegate methods to perform some animations when panel is moving. Using both of them breaks panel interactivity.
Expected behavior
floatingPanelState(_:) and view updates on delegate methods don't break behavior of panel
Screen.Recording.2026-02-11.at.15.31.56.mov
Actual behavior
When trying to change state of a panel by swiping it moves properly and parent view updates properly
Screen.Recording.2026-02-11.at.15.29.17.mov
Steps to reproduce
MyCoordinator
final class MyCoordinator: FloatingPanelCoordinator {
enum Event {
case willBeginDragging
case didEndAttracting
}
let action: (Event) -> Void
var proxy: FloatingPanel.FloatingPanelProxy
private lazy var delegate: FloatingPanelControllerDelegate? = self
init(action: @escaping (Event) -> Void) {
self.action = action
self.proxy = .init(controller: FloatingPanelController())
}
func setupFloatingPanel<Main, Content>(mainHostingController: UIHostingController<Main>, contentHostingController: UIHostingController<Content>) where Main : View, Content : View {
controller.delegate = delegate
controller.set(contentViewController: contentHostingController)
controller.addPanel(toParent: mainHostingController, animated: false)
}
func onUpdate<Representable>(context: UIViewControllerRepresentableContext<Representable>) where Representable : UIViewControllerRepresentable {
}
}
extension MyCoordinator: FloatingPanelControllerDelegate {
func floatingPanelWillBeginDragging(_ fpc: FloatingPanelController) {
action(.willBeginDragging)
}
func floatingPanelDidEndAttracting(_ fpc: FloatingPanelController) {
action(.didEndAttracting)
}
}ContentView
struct ContentView: View {
@State var floatingState: FloatingPanelState? = .half
@State var opacity: Double = 1
var body: some View {
VStack {
Image(systemName: "globe")
.imageScale(.large)
.foregroundStyle(.tint)
.opacity(opacity)
.animation(.easeIn(duration: 0.1), value: opacity)
Text("Hello, world!")
Spacer(minLength: .zero)
}
.floatingPanel(coordinator: MyCoordinator.self, onEvent: onEvent) { _ in
Color.red
}
.floatingPanelState($floatingState) // <-- if this line is commented all works fine
}
func onEvent(_ event: MyCoordinator.Event) {
switch event {
case .willBeginDragging:
DispatchQueue.main.async {
opacity = 0
}
case .didEndAttracting:
DispatchQueue.main.async {
opacity = 1
}
}
}
}Environment
Library version
3.2.1
Installation method
Swift Package Manager
iOS version(s)
18.6
Xcode version
16.4