fix: working dentent setting and improved performance (#22)

Example/BottomSheetExample/Apple Applications/StocksExample.swift

@@ -17,6 +17,10 @@ struct StocksExample: View {
  settings.isPresented.toggle()
  }
 
+ Button("Change") {
+ settings.selectedDetent = .large
+ }
+
  Color.clear
  .navigationBarTitleDisplayMode(.inline)
  .navigationTitle("\(settings.translation.rounded())")

Example/BottomSheetExample/ExampleOverview.swift

@@ -42,7 +42,8 @@ struct ExampleOverview: View {
  return AnyView(
  StocksMainContent()
  .presentationDetentsPlus(
- [.height(244), .medium, .large]
+ [.height(244), .medium, .large],
+ selection: $settings.selectedDetent
  )
  )
  default:
@@ -76,10 +77,12 @@ struct ExampleOverview: View {
  Color(UIColor.secondarySystemBackground)
  .cornerRadius(12, corners: [.topLeft, .topRight])
  ),
+ onDrag: { translation in
+ settings.translation = translation
+ },
  header: { headerContent() },
  main: {
  mainContent()
- .onSheetDrag(translation: $settings.translation)
  }
  )
  .overlay(

Sources/BottomSheet/BottomSheet.swift

@@ -3,30 +3,28 @@ import SwiftUI
 struct SheetPlus<HContent: View, MContent: View, Background: View>: ViewModifier {
  @Binding private var isPresented: Bool
 
- let onDismiss: () -> Void
- let hcontent: HContent
- let mcontent: MContent
- let animationCurve: SheetAnimation
- let background: Background
+ @State private var translation: CGFloat = 0
+ @State private var sheetConfig: SheetPlusConfig?
 
- @State private var offset = 0.0
  @State private var newValue = 0.0
- @State private var translation: CGFloat = 0
  @State private var startTime: DragGesture.Value?
 
  @State private var detents: Set<PresentationDetent> = []
- @State private var preferenceKey: SheetPlusConfigKey?
  @State private var limits: (min: CGFloat, max: CGFloat) = (min: 0, max: 0)
 
- @State private var translationKey: SheetPlusTranslationKey?
-
- var onDrag: ((_ position: CGFloat) -> Void)?
+ let mainContent: MContent
+ let headerContent: HContent
+ let animationCurve: SheetAnimation
+ let onDismiss: () -> Void
+ let onDrag: (CGFloat) -> Void
+ let background: Background
 
- public init(
+ init(
  isPresented: Binding<Bool>,
  animationCurve: SheetAnimation,
  background: Background,
  onDismiss: @escaping () -> Void,
+ onDrag: @escaping (CGFloat) -> Void,
  @ViewBuilder hcontent: () -> HContent,
  @ViewBuilder mcontent: () -> MContent
  ) {
@@ -35,122 +33,99 @@ struct SheetPlus<HContent: View, MContent: View, Background: View>: ViewModifier
  self.animationCurve = animationCurve
  self.background = background
  self.onDismiss = onDismiss
+ self.onDrag = onDrag
 
- self.hcontent = hcontent()
- self.mcontent = mcontent()
+ self.headerContent = hcontent()
+ self.mainContent = mcontent()
  }
 
  func body(content: Content) -> some View {
  ZStack() {
  content
-
- VStack {
- if isPresented {
- GeometryReader { geometry in
- VStack(spacing: 0) {
- hcontent
- .contentShape(Rectangle())
- .gesture(
- DragGesture(coordinateSpace: .global)
- .onChanged { value in
- translation -= value.location.y - value.startLocation.y - newValue
- newValue = value.location.y - value.startLocation.y
-
- if startTime == nil {
- startTime = value
- }
+
+ if isPresented {
+ GeometryReader { geometry in
+ VStack(spacing: 0) {
+ headerContent
+ .contentShape(Rectangle())
+ .gesture(
+ DragGesture(coordinateSpace: .global)
+ .onChanged { value in
+ translation -= value.location.y - value.startLocation.y - newValue
+ newValue = value.location.y - value.startLocation.y
+
+ if startTime == nil {
+ startTime = value
  }
-  .onEnded { value in
-  // Reset the distance on release so we start with a
-  // clean translation next time
-  newValue = 0
-  
-  // Calculate velocity based on pt/s so it matches the UIPanGesture
-  let distance: CGFloat = value.translation.height
-  let time: CGFloat = value.time.timeIntervalSince(startTime!.time)
-  
-  let yVelocity: CGFloat = -1 * ((distance / time) / 1000)
-  startTime = nil
-  
-  if let result = snapBottomSheet(translation, detents, yVelocity) {
-  translation = result.size
-  preferenceKey?.$selection.wrappedValue = result
- }
+ }
+ .onEnded { value in
+ // Reset the distance on release so we start with a
+ // clean translation next time
+ newValue = 0
+
+ // Calculate velocity based on pt/s so it matches the UIPanGesture
+ let distance: CGFloat = value.translation.height
+ let time: CGFloat = value.time.timeIntervalSince(startTime!.time)
+
+ let yVelocity: CGFloat = -1 * ((distance / time) / 1000)
+ startTime = nil
+
+ if let result = snapBottomSheet(translation, detents, yVelocity) {
+ translation = result.size
+ sheetConfig?.selectedDetent = result
  }
- )
-
-
- UIScrollViewWrapper(
- translation: $translation,
- preferenceKey: $preferenceKey,
- detents: $detents,
- limits: $limits
- ) {
- mcontent
- .frame(width: geometry.size.width)
- }
-
- }
- .background(background)
- .frame(height:
- (limits.max - geometry.safeAreaInsets.top) > 0
- ? limits.max - geometry.safeAreaInsets.top
- : limits.max
- )
- .offset(y: UIScreen.main.bounds.height - translation)
- .onChange(of: translation) { newValue in
- if limits.max == 0 { return }
- translation = min(limits.max, max(newValue, limits.min))
- }
- .onAnimationChange(of: translation) { value in
- translationKey?.$translation.wrappedValue = value
- }
- .animation(
- .interpolatingSpring(
- mass: animationCurve.mass,
- stiffness: animationCurve.stiffness,
- damping: animationCurve.damping
+ }
  )
- )
- .onDisappear {
- translation = 0
- detents = []
- offset = 0
- newValue = 0
-  limits = (min: 0, max: 0)
-
- onDismiss()
+
+ UIScrollViewWrapper(
+ translation: $translation,
+ preferenceKey: $sheetConfig,
+ limits: limits,
+ detents: detents
+ ) {
+ mainContent
+  .frame(width: geometry.size.width)
  }
  }
- .edgesIgnoringSafeArea([.bottom])
- .transition(.move(edge: .bottom))
+ .background(background)
+ .frame(height:
+ (limits.max - geometry.safeAreaInsets.top) > 0
+ ? limits.max - geometry.safeAreaInsets.top
+ : limits.max
+ )
+ .onChange(of: translation) { newValue in
+ // Small little hack to make the iOS scroll behaviour work smoothly
+ if limits.max == 0 { return }
+ translation = min(limits.max, max(newValue, limits.min))
+ }
+ .onAnimationChange(of: translation) { value in
+ onDrag(value)
+ }
+ .offset(y: UIScreen.main.bounds.height - translation)
+ .onDisappear {
+ translation = 0
+ detents = []
+
+ onDismiss()
+ }
+ .animation(
+ .interpolatingSpring(
+ mass: animationCurve.mass,
+ stiffness: animationCurve.stiffness,
+ damping: animationCurve.damping
+ )
+ )
  }
+ .edgesIgnoringSafeArea([.bottom])
+ .transition(.move(edge: .bottom))
  }
- .animation(
- .interpolatingSpring(
- mass: animationCurve.mass,
- stiffness: animationCurve.stiffness,
- damping: animationCurve.damping
- )
- )
- }
- .onPreferenceChange(SheetPlusTranslation.self) { value in
- self.translationKey = value
  }
- .onPreferenceChange(SheetPlusConfiguration.self) { value in
- /// Quick hack to prevent the scrollview from resetting the height when keyboard shows up.
- /// Replace if the root cause has been located.
- if value.detents.count == 0 { return }
-
+ .onPreferenceChange(SheetPlusKey.self) { value in
+ sheetConfig = value
+ translation = value.translation
+
  detents = value.detents
- limits = detentLimits(detents: value.detents)
-
- if value.selection == .height(.zero) {
- translation = limits.min
- } else {
- translation = value.$selection.wrappedValue.size
- }
-
+ limits = detentLimits(detents: detents)
  }
  }
 }

Sources/BottomSheet/Preference Keys/ConfigKey.swift

@@ -7,29 +7,21 @@
 
 import SwiftUI
 
-struct SheetPlusConfigKey: Equatable {
- let id = UUID().uuidString
-
+struct SheetPlusConfig: Equatable {
  let detents: Set<PresentationDetent>
- @Binding var selection: PresentationDetent
+ @Binding var selectedDetent: PresentationDetent
+ let translation: CGFloat
 
- init(
- detents: Set<PresentationDetent>,
- selection: Binding<PresentationDetent> = .constant(.height(.zero))
- ) {
- self.detents = detents
- self._selection = selection
- }
 
- static func == (lhs: SheetPlusConfigKey, rhs: SheetPlusConfigKey) -> Bool {
- return lhs.id == rhs.id
+ static func == (lhs: SheetPlusConfig, rhs: SheetPlusConfig) -> Bool {
+ return lhs.selectedDetent == rhs.selectedDetent && lhs.translation == rhs.translation && lhs.detents == rhs.detents
  }
 }
 
-struct SheetPlusConfiguration: PreferenceKey {
- static var defaultValue: SheetPlusConfigKey = SheetPlusConfigKey(detents: [])
+struct SheetPlusKey: PreferenceKey {
+ static var defaultValue: SheetPlusConfig = SheetPlusConfig(detents: [], selectedDetent: .constant(.height(.zero)), translation: 0)
 
- static func reduce(value: inout SheetPlusConfigKey, nextValue: () -> SheetPlusConfigKey) {
+ static func reduce(value: inout SheetPlusConfig, nextValue: () -> SheetPlusConfig) {
  value = nextValue()
  }
 }