Pass checkEdges to avoid recomposition/layout shift in hot code paths

Sources/SkipUI/SkipUI/Compose/ComposeLayouts.swift

@@ -1,10 +1,12 @@
 // Copyright 2023–2025 Skip
 // SPDX-License-Identifier: LGPL-3.0-only WITH LGPL-3.0-linking-exception
 #if SKIP
+import android.util.Log
 import androidx.compose.foundation.layout.Box
 import androidx.compose.foundation.layout.requiredHeight
 import androidx.compose.foundation.layout.requiredWidth
 import androidx.compose.runtime.Composable
+import androidx.compose.runtime.LaunchedEffect
 import androidx.compose.runtime.MutableState
 import androidx.compose.runtime.mutableStateOf
 import androidx.compose.runtime.remember
@@ -142,9 +144,9 @@ private func flexibleLayoutFloat(_ value: CGFloat?) -> Float? {
 }
 
 /// Layout the given view to ignore the given safe areas.
-@Composable func IgnoresSafeAreaLayout(content: Renderable, context: ComposeContext, expandInto: Edge.Set) {
+@Composable func IgnoresSafeAreaLayout(content: Renderable, context: ComposeContext, expandInto: Edge.Set, logTag: String = "") {
     ComposeContainer(modifier: context.modifier) { modifier in
-        IgnoresSafeAreaLayout(expandInto: expandInto, modifier: modifier) { _, _ in
+        IgnoresSafeAreaLayout(expandInto: expandInto, checkEdges: expandInto, modifier: modifier, logTag: logTag) { _, _ in
             content.Render(context.content())
         }
     }
@@ -156,12 +158,22 @@ private func flexibleLayoutFloat(_ value: CGFloat?) -> Float? {
 ///     the given closure as a pixel rect.
 /// - Parameter checkEdges: Which edges to check to see if we're against a safe area. Any matching edges will be
 ///     passed to the given closure.
-@Composable func IgnoresSafeAreaLayout(expandInto: Edge.Set, checkEdges: Edge.Set = [], modifier: Modifier = Modifier, target: @Composable (IntRect, Edge.Set) -> Void) {
+/// - Parameter logTag: When non-empty, emits Android ``Log`` lines with tag `SkipUI.ISAL.<logTag>` (e.g. filter logcat `SkipUI.ISAL.List`).
+@Composable func IgnoresSafeAreaLayout(expandInto: Edge.Set, checkEdges: Edge.Set = [], modifier: Modifier = Modifier, logTag: String = "", target: @Composable (IntRect, Edge.Set) -> Void) {
     guard let safeArea = EnvironmentValues.shared._safeArea else {
+        if !logTag.isEmpty {
+            Log.d("SkipUI.ISAL.\(logTag)", "no SafeArea in environment; skipping expansion")
+        }
         target(IntRect.Zero, [])
         return
     }
 
+    if !logTag.isEmpty {
+        LaunchedEffect(logTag, expandInto.rawValue, checkEdges.rawValue) {
+            Log.d("SkipUI.ISAL.\(logTag)", "init expandInto=\(expandInto) checkEdges=\(checkEdges) edgesState(initial)=\(checkEdges)")
+        }
+    }
+
     // Note: We only allow edges we're interested in to affect our internal state and output. This is critical
     // for reducing recompositions, especially during e.g. navigation animations. We also match our internal
     // state to our output to ensure we aren't re-calling the target block when output hasn't changed
@@ -207,8 +219,15 @@ private func flexibleLayoutFloat(_ value: CGFloat?) -> Float? {
         return ComposeResult.ok
     } in: {
         Layout(modifier: modifier.onGloballyPositionedInWindow {
-            let edges = adjacentSafeAreaEdges(bounds: $0, safeArea: safeArea, isRTL: isRTL, checkEdges: expandInto.union(checkEdges))
-            edgesState.value = edges
+            let probeEdges = expandInto.union(checkEdges)
+            let newEdges = adjacentSafeAreaEdges(bounds: $0, safeArea: safeArea, isRTL: isRTL, checkEdges: probeEdges)
+            if !logTag.isEmpty {
+                let previous = edgesState.value
+                if newEdges != previous {
+                    Log.d("SkipUI.ISAL.\(logTag)", "onGloballyPositionedInWindow adjacentEdges \(previous) -> \(newEdges) (probeEdges=\(probeEdges))")
+                }
+            }
+            edgesState.value = newEdges
         }, content: {
             let expansion = IntRect(top: expansionTop, left: expansionLeft, bottom: expansionBottom, right: expansionRight)
             target(expansion, edges.intersection(checkEdges))

Sources/SkipUI/SkipUI/Containers/LazyVGrid.swift

@@ -76,7 +76,7 @@ public struct LazyVGrid: View, Renderable {
         let renderables = content.EvaluateLazyItems(level: 0, context: context)
         let itemCollector = remember { mutableStateOf(LazyItemCollector()) }
         ComposeContainer(axis: .vertical, scrollAxes: scrollAxes, modifier: context.modifier, fillWidth: true) { modifier in
-            IgnoresSafeAreaLayout(expandInto: [], checkEdges: [.bottom], modifier: modifier) { _, safeAreaEdges in
+            IgnoresSafeAreaLayout(expandInto: [], checkEdges: [.bottom], modifier: modifier, logTag: "LazyVGrid") { _, safeAreaEdges in
                 // Integrate with our scroll-to-top and ScrollViewReader
                 let gridState = rememberLazyGridState(initialFirstVisibleItemIndex = isSearchable ? 1 : 0)
                 let flingBehavior = scrollTargetBehavior is ViewAlignedScrollTargetBehavior ? rememberSnapFlingBehavior(gridState, SnapPosition.Start) : ScrollableDefaults.flingBehavior()

Sources/SkipUI/SkipUI/Containers/LazyVStack.swift

@@ -69,7 +69,7 @@ public struct LazyVStack : View, Renderable {
         let renderables = content.EvaluateLazyItems(level: 0, context: context)
         let itemCollector = remember { mutableStateOf(LazyItemCollector()) }
         ComposeContainer(axis: .vertical, scrollAxes: scrollAxes, modifier: context.modifier, fillWidth: true) { modifier in
-            IgnoresSafeAreaLayout(expandInto: [], checkEdges: [.bottom], modifier: modifier) { _, safeAreaEdges in
+            IgnoresSafeAreaLayout(expandInto: [], checkEdges: [.bottom], modifier: modifier, logTag: "LazyVStack") { _, safeAreaEdges in
                 // Integrate with our scroll-to-top and ScrollViewReader
                 let listState = rememberLazyListState(initialFirstVisibleItemIndex = isSearchable ? 1 : 0)
                 let flingBehavior = scrollTargetBehavior is ViewAlignedScrollTargetBehavior ? rememberSnapFlingBehavior(listState, SnapPosition.Start) : ScrollableDefaults.flingBehavior()

Sources/SkipUI/SkipUI/Containers/List.swift

@@ -123,7 +123,7 @@ public final class List : View, Renderable {
         var ignoresSafeAreaEdges: Edge.Set = [.top, .bottom]
         ignoresSafeAreaEdges.formIntersection(safeArea?.absoluteSystemBarEdges ?? [])
         ComposeContainer(scrollAxes: .vertical, modifier: context.modifier, fillWidth: true, fillHeight: true, then: Modifier.background(BackgroundColor(styling: styling, isItem: false))) { modifier in
-            IgnoresSafeAreaLayout(expandInto: ignoresSafeAreaEdges, checkEdges: [.bottom], modifier: modifier) { safeAreaExpansion, safeAreaEdges in
+            IgnoresSafeAreaLayout(expandInto: ignoresSafeAreaEdges, checkEdges: [.bottom], modifier: modifier, logTag: "List") { safeAreaExpansion, safeAreaEdges in
                 var containerModifier: Modifier
                 let refreshing = remember { mutableStateOf(false) }
                 let refreshAction = EnvironmentValues.shared.refresh

Sources/SkipUI/SkipUI/Containers/Navigation.swift

@@ -147,7 +147,7 @@ public struct NavigationStack : View, Renderable {
             // When we layout, only extend into safe areas that are due to system bars, not into any app chrome
             var ignoresSafeAreaEdges: Edge.Set = [.top, .bottom]
             ignoresSafeAreaEdges.formIntersection(safeArea?.absoluteSystemBarEdges ?? [])
-            IgnoresSafeAreaLayout(expandInto: ignoresSafeAreaEdges) { _, _ in
+            IgnoresSafeAreaLayout(expandInto: ignoresSafeAreaEdges, checkEdges: ignoresSafeAreaEdges, logTag: "NavigationStack") { _, _ in
                 ComposeContainer(modifier: context.modifier, fillWidth: true, fillHeight: true) { modifier in
                     let isRTL = EnvironmentValues.shared.layoutDirection == LayoutDirection.rightToLeft
                     NavHost(navController: navController, startDestination: Navigator.rootRoute, modifier: modifier) {

Sources/SkipUI/SkipUI/Containers/ScrollView.swift

@@ -81,7 +81,7 @@ public struct ScrollView : View, Renderable {
 
         let contentContext = context.content()
         ComposeContainer(scrollAxes: effectiveScrollAxes, modifier: context.modifier, fillWidth: axes.contains(.horizontal), fillHeight: axes.contains(.vertical)) { modifier in
-            IgnoresSafeAreaLayout(expandInto: [], checkEdges: [.bottom], modifier: modifier) { _, safeAreaEdges in
+            IgnoresSafeAreaLayout(expandInto: [], checkEdges: [.bottom], modifier: modifier, logTag: "ScrollView") { _, safeAreaEdges in
                 var containerModifier: Modifier = Modifier
                 if wantsVerticalScroll {
                     containerModifier = containerModifier.fillMaxHeight()

Sources/SkipUI/SkipUI/Containers/TabView.swift

@@ -368,7 +368,7 @@ public struct TabView : View, Renderable {
         // tab switches
         var ignoresSafeAreaEdges: Edge.Set = [.bottom, .top]
         ignoresSafeAreaEdges.formIntersection(safeArea?.absoluteSystemBarEdges ?? [])
-        IgnoresSafeAreaLayout(expandInto: ignoresSafeAreaEdges) { _, _ in
+        IgnoresSafeAreaLayout(expandInto: ignoresSafeAreaEdges, checkEdges: ignoresSafeAreaEdges, logTag: "TabView") { _, _ in
             ComposeContainer(modifier: context.modifier, fillWidth: true, fillHeight: true) { modifier in
                 // Don't use a Scaffold: it clips content beyond its bounds and prevents .ignoresSafeArea modifiers from working
                 Column(modifier: modifier.background(Color.background.colorImpl())) {

Sources/SkipUI/SkipUI/Containers/Table.swift

@@ -60,7 +60,7 @@ public final class Table<ObjectType, ID> : View, Renderable where ObjectType: Id
         ignoresSafeAreaEdges.formIntersection(safeArea?.absoluteSystemBarEdges ?? [])
         let itemContext = context.content()
         ComposeContainer(scrollAxes: .vertical, modifier: context.modifier, fillWidth: true, fillHeight: true) { modifier in
-            IgnoresSafeAreaLayout(expandInto: ignoresSafeAreaEdges, modifier: modifier) { safeAreaExpansion, _ in
+            IgnoresSafeAreaLayout(expandInto: ignoresSafeAreaEdges, modifier: modifier, logTag: "Table") { safeAreaExpansion, _ in
                 let density = LocalDensity.current
                 let headerSafeAreaHeight = with(density) { safeAreaExpansion.top.toDp() }
                 let footerSafeAreaHeight = with(density) { safeAreaExpansion.bottom.toDp() }