Remove onSizeChange in favor of new native APIs

Sources/ArcGISToolkit/Components/FloorFilter/LevelSelector.swift

@@ -114,19 +114,38 @@ extension LevelSelector {
     /// A scrollable list of buttons; one for each level to be displayed.
     /// - Returns: The scrollable list of level buttons.
     @ViewBuilder func makeLevelButtons() -> some View {
-        ScrollViewReader { proxy in
+        let scrollView = ScrollViewReader { proxy in
             ScrollView {
-                VStack(spacing: 4) {
+                let list = VStack(spacing: 4) {
                     ForEach(filteredLevels, id: \.id) { level in
                         makeLevelButton(level)
                     }
                 }
-                .onSizeChange { contentHeight = $0.height }
+                if #available (iOS 18.0, *) {
+                    list
+                } else {
+                    list
+                        .onGeometryChange(for: CGFloat.self) { proxy in
+                            proxy.frame(in: .global).height
+                        } action: { newHeight in
+                            contentHeight = newHeight
+                        }
+                }
             }
             .frame(maxHeight: contentHeight)
             .onAppear { scrollToSelectedLevel(with: proxy) }
             .onChange(isCollapsed) { _ in scrollToSelectedLevel(with: proxy) }
         }
+        if #available (iOS 18.0, *) {
+            scrollView
+                .onScrollGeometryChange(for: CGFloat.self) { geometry in
+                    geometry.contentSize.height
+                } action: { _, newValue in
+                    contentHeight = newValue
+                }
+        } else {
+            scrollView
+        }
     }
 
     /// Determines a appropriate color for a button in the floor level list.

Sources/ArcGISToolkit/Components/Popups/MediaPopupElementView.swift

@@ -82,8 +82,10 @@ struct MediaPopupElementView: View {
                     }
                 }
             }
-            .onSizeChange {
-                width = $0.width * widthScaleFactor
+            .onGeometryChange(for: CGFloat.self) { proxy in
+                proxy.frame(in: .global).width
+            } action: { newValue in
+                width = newValue * widthScaleFactor
             }
         }
 

Sources/ArcGISToolkit/Components/Scalebar/Scalebar.swift

@@ -197,8 +197,10 @@ public struct Scalebar: View {
                 }
             }
         }
-        .onSizeChange {
-            height = $0.height
+        .onGeometryChange(for: CGFloat.self) { proxy in
+            proxy.frame(in: .global).height
+        } action: { newValue in
+            height = newValue
         }
         .frame(
             width: $viewModel.displayLength.wrappedValue,

Sources/ArcGISToolkit/Extensions/SwiftUI/View.swift

@@ -65,22 +65,6 @@ extension View {
         modifier(KeyboardStateChangedModifier(action: action))
     }
 
-    /// Returns a new `View` that allows a parent `View` to be informed of a child view's size.
-    /// - Parameter perform: The closure to be executed when the content size of the receiver
-    /// changes.
-    /// - Returns: A new `View`.
-    func onSizeChange(perform: @escaping (CGSize) -> Void) -> some View {
-        background(
-            GeometryReader { geometry in
-                Color.clear
-                    .preference(
-                        key: SizePreferenceKey.self, value: geometry.size
-                    )
-            }
-        )
-        .onPreferenceChange(SizePreferenceKey.self, perform: perform)
-    }
-
     /// Adds an equal padding amount to the horizontal edges of this view if the target environment
     /// is Mac Catalyst.
     /// - Parameter length: An amount, given in points, to pad this view on the horizontal edges.