Update Scaffold fork (#10143)

https://android-review.googlesource.com/c/platform/frameworks/support/+/2690433

presentation-core/src/main/java/tachiyomi/presentation/core/components/material/Scaffold.kt

@@ -14,36 +14,39 @@
  * limitations under the License.
  */
 
+@file:Suppress("KDocUnresolvedReference")
+
 package tachiyomi.presentation.core.components.material
 
-import androidx.compose.foundation.layout.MutableWindowInsets
 import androidx.compose.foundation.layout.PaddingValues
+import androidx.compose.foundation.layout.Spacer
 import androidx.compose.foundation.layout.WindowInsets
-import androidx.compose.foundation.layout.asPaddingValues
-import androidx.compose.foundation.layout.calculateEndPadding
-import androidx.compose.foundation.layout.calculateStartPadding
-import androidx.compose.foundation.layout.exclude
-import androidx.compose.foundation.layout.onConsumedWindowInsetsChanged
+import androidx.compose.foundation.layout.windowInsetsBottomHeight
+import androidx.compose.foundation.layout.windowInsetsEndWidth
+import androidx.compose.foundation.layout.windowInsetsStartWidth
+import androidx.compose.foundation.layout.windowInsetsTopHeight
 import androidx.compose.material3.ExperimentalMaterial3Api
+import androidx.compose.material3.FabPosition
 import androidx.compose.material3.MaterialTheme
 import androidx.compose.material3.ScaffoldDefaults
 import androidx.compose.material3.TopAppBarDefaults
 import androidx.compose.material3.TopAppBarScrollBehavior
 import androidx.compose.material3.contentColorFor
-import androidx.compose.material3.rememberTopAppBarState
 import androidx.compose.runtime.Composable
-import androidx.compose.runtime.CompositionLocalProvider
 import androidx.compose.runtime.Immutable
+import androidx.compose.runtime.getValue
+import androidx.compose.runtime.mutableStateOf
 import androidx.compose.runtime.remember
-import androidx.compose.runtime.staticCompositionLocalOf
+import androidx.compose.runtime.setValue
 import androidx.compose.ui.Modifier
 import androidx.compose.ui.graphics.Color
 import androidx.compose.ui.input.nestedscroll.nestedScroll
-import androidx.compose.ui.layout.SubcomposeLayout
+import androidx.compose.ui.layout.Layout
 import androidx.compose.ui.unit.Constraints
+import androidx.compose.ui.unit.Dp
 import androidx.compose.ui.unit.LayoutDirection
 import androidx.compose.ui.unit.dp
-import androidx.compose.ui.unit.max
+import androidx.compose.ui.unit.offset
 import androidx.compose.ui.util.fastForEach
 import androidx.compose.ui.util.fastMap
 import androidx.compose.ui.util.fastMaxBy
@@ -70,8 +73,6 @@ import kotlin.math.max
  * * Pass scroll behavior to top bar by default
  * * Remove height constraint for expanded app bar
  * * Also take account of fab height when providing inner padding
- * * Fixes for fab and snackbar horizontal placements when [contentWindowInsets] is used
- * * Handle consumed window insets
  * * Add startBar slot for Navigation Rail
  *
  * @param modifier the [Modifier] to be applied to this scaffold
@@ -99,9 +100,7 @@ import kotlin.math.max
 @Composable
 fun Scaffold(
     modifier: Modifier = Modifier,
-    topBarScrollBehavior: TopAppBarScrollBehavior = TopAppBarDefaults.pinnedScrollBehavior(
-        rememberTopAppBarState(),
-    ),
+    topBarScrollBehavior: TopAppBarScrollBehavior = TopAppBarDefaults.pinnedScrollBehavior(),
     topBar: @Composable (TopAppBarScrollBehavior) -> Unit = {},
     bottomBar: @Composable () -> Unit = {},
     startBar: @Composable () -> Unit = {},
@@ -113,16 +112,9 @@ fun Scaffold(
     contentWindowInsets: WindowInsets = ScaffoldDefaults.contentWindowInsets,
     content: @Composable (PaddingValues) -> Unit,
 ) {
-    // Tachiyomi: Handle consumed window insets
-    val remainingWindowInsets = remember { MutableWindowInsets() }
     androidx.compose.material3.Surface(
         modifier = Modifier
             .nestedScroll(topBarScrollBehavior.nestedScrollConnection)
-            .onConsumedWindowInsetsChanged {
-                remainingWindowInsets.insets = contentWindowInsets.exclude(
-                    it,
-                )
-            }
             .then(modifier),
         color = containerColor,
         contentColor = contentColor,
@@ -134,7 +126,7 @@ fun Scaffold(
             bottomBar = bottomBar,
             content = content,
             snackbar = snackbarHost,
-            contentWindowInsets = remainingWindowInsets,
+            contentWindowInsets = contentWindowInsets,
             fab = floatingActionButton,
         )
     }
@@ -152,7 +144,6 @@ fun Scaffold(
  * @param bottomBar the content to place at the bottom of the [Scaffold], on top of the
  * [content], typically a [NavigationBar].
  */
-@OptIn(ExperimentalMaterial3Api::class)
 @Composable
 private fun ScaffoldLayout(
     fabPosition: FabPosition,
@@ -164,7 +155,47 @@ private fun ScaffoldLayout(
     contentWindowInsets: WindowInsets,
     bottomBar: @Composable () -> Unit,
 ) {
-    SubcomposeLayout { constraints ->
+    // Create the backing values for the content padding
+    // These values will be updated during measurement, but before measuring and placing
+    // the body content
+    var topContentPadding by remember { mutableStateOf(0.dp) }
+    var startContentPadding by remember { mutableStateOf(0.dp) }
+    var endContentPadding by remember { mutableStateOf(0.dp) }
+    var bottomContentPadding by remember { mutableStateOf(0.dp) }
+
+    val contentPadding = remember {
+        object : PaddingValues {
+            override fun calculateLeftPadding(layoutDirection: LayoutDirection): Dp =
+                when (layoutDirection) {
+                    LayoutDirection.Ltr -> startContentPadding
+                    LayoutDirection.Rtl -> endContentPadding
+                }
+
+            override fun calculateTopPadding(): Dp = topContentPadding
+
+            override fun calculateRightPadding(layoutDirection: LayoutDirection): Dp =
+                when (layoutDirection) {
+                    LayoutDirection.Ltr -> endContentPadding
+                    LayoutDirection.Rtl -> startContentPadding
+                }
+
+            override fun calculateBottomPadding(): Dp = bottomContentPadding
+        }
+    }
+    Layout(
+        contents = listOf(
+            { Spacer(Modifier.windowInsetsTopHeight(contentWindowInsets)) },
+            { Spacer(Modifier.windowInsetsBottomHeight(contentWindowInsets)) },
+            { Spacer(Modifier.windowInsetsStartWidth(contentWindowInsets)) },
+            { Spacer(Modifier.windowInsetsEndWidth(contentWindowInsets)) },
+            startBar,
+            topBar,
+            snackbar,
+            fab,
+            bottomBar,
+            { content(contentPadding) },
+        ),
+    ) { measurables, constraints ->
         val layoutWidth = constraints.maxWidth
         val layoutHeight = constraints.maxHeight
 
@@ -175,119 +206,117 @@ private fun ScaffoldLayout(
          */
         val topBarConstraints = looseConstraints.copy(maxHeight = Constraints.Infinity)
 
-        layout(layoutWidth, layoutHeight) {
-            val leftInset = contentWindowInsets.getLeft(this@SubcomposeLayout, layoutDirection)
-            val rightInset = contentWindowInsets.getRight(this@SubcomposeLayout, layoutDirection)
-            val bottomInset = contentWindowInsets.getBottom(this@SubcomposeLayout)
+        val topInsetsPlaceables = measurables[0].single()
+            .measure(looseConstraints)
+        val bottomInsetsPlaceables = measurables[1].single()
+            .measure(looseConstraints)
+        val startInsetsPlaceables = measurables[2].single()
+            .measure(looseConstraints)
+        val endInsetsPlaceables = measurables[3].single()
+            .measure(looseConstraints)
 
-            // Tachiyomi: Add startBar slot for Navigation Rail
-            val startBarPlaceables = subcompose(ScaffoldLayoutContent.StartBar, startBar).fastMap {
-                it.measure(looseConstraints)
-            }
-            val startBarWidth = startBarPlaceables.fastMaxBy { it.width }?.width ?: 0
+        val startInsetsWidth = startInsetsPlaceables.width
+        val endInsetsWidth = endInsetsPlaceables.width
 
-            // Tachiyomi: layoutWidth after horizontal insets
-            val insetLayoutWidth = layoutWidth - leftInset - rightInset - startBarWidth
+        val topInsetsHeight = topInsetsPlaceables.height
+        val bottomInsetsHeight = bottomInsetsPlaceables.height
 
-            val topBarPlaceables = subcompose(ScaffoldLayoutContent.TopBar, topBar).fastMap {
-                it.measure(topBarConstraints)
-            }
+        // Tachiyomi: Add startBar slot for Navigation Rail
+        val startBarPlaceables = measurables[4]
+            .fastMap { it.measure(looseConstraints) }
 
-            val topBarHeight = topBarPlaceables.fastMaxBy { it.height }?.height ?: 0
+        val startBarWidth = startBarPlaceables.fastMaxBy { it.width }?.width ?: 0
 
-            val snackbarPlaceables = subcompose(ScaffoldLayoutContent.Snackbar, snackbar).fastMap {
-                it.measure(looseConstraints)
-            }
+        val topBarPlaceables = measurables[5]
+            .fastMap { it.measure(topBarConstraints) }
 
-            val snackbarHeight = snackbarPlaceables.fastMaxBy { it.height }?.height ?: 0
-            val snackbarWidth = snackbarPlaceables.fastMaxBy { it.width }?.width ?: 0
+        val topBarHeight = topBarPlaceables.fastMaxBy { it.height }?.height ?: 0
 
-            // Tachiyomi: Calculate insets for snackbar placement offset
-            val snackbarLeft = if (snackbarPlaceables.isNotEmpty()) {
-                (insetLayoutWidth - snackbarWidth) / 2 + leftInset
-            } else {
-                0
-            }
+        val bottomPlaceablesConstraints = looseConstraints.offset(
+            -startInsetsWidth - endInsetsWidth,
+            -bottomInsetsHeight,
+        )
 
-            val fabPlaceables =
-                subcompose(ScaffoldLayoutContent.Fab, fab).fastMap { measurable ->
-                    measurable.measure(looseConstraints)
-                }
+        val snackbarPlaceables = measurables[6]
+            .fastMap { it.measure(bottomPlaceablesConstraints) }
+
+        val snackbarHeight = snackbarPlaceables.fastMaxBy { it.height }?.height ?: 0
+        val snackbarWidth = snackbarPlaceables.fastMaxBy { it.width }?.width ?: 0
 
-            val fabWidth = fabPlaceables.fastMaxBy { it.width }?.width ?: 0
-            val fabHeight = fabPlaceables.fastMaxBy { it.height }?.height ?: 0
+        val fabPlaceables = measurables[7]
+            .fastMap { it.measure(bottomPlaceablesConstraints) }
 
-            val fabPlacement = if (fabPlaceables.isNotEmpty() && fabWidth != 0 && fabHeight != 0) {
-                // FAB distance from the left of the layout, taking into account LTR / RTL
-                // Tachiyomi: Calculate insets for fab placement offset
-                val fabLeftOffset = if (fabPosition == FabPosition.End) {
+        val fabWidth = fabPlaceables.fastMaxBy { it.width }?.width ?: 0
+        val fabHeight = fabPlaceables.fastMaxBy { it.height }?.height ?: 0
+
+        val fabPlacement = if (fabWidth > 0 && fabHeight > 0) {
+            // FAB distance from the left of the layout, taking into account LTR / RTL
+            val fabLeftOffset = when (fabPosition) {
+                FabPosition.Start -> {
                     if (layoutDirection == LayoutDirection.Ltr) {
-                        layoutWidth - FabSpacing.roundToPx() - fabWidth - rightInset
+                        FabSpacing.roundToPx()
                     } else {
-                        FabSpacing.roundToPx() + leftInset
+                        layoutWidth - FabSpacing.roundToPx() - fabWidth
                     }
-                } else {
-                    leftInset + ((insetLayoutWidth - fabWidth) / 2)
                 }
-
-                FabPlacement(
-                    left = fabLeftOffset,
-                    width = fabWidth,
-                    height = fabHeight,
-                )
-            } else {
-                null
+                FabPosition.End, FabPosition.EndOverlay -> {
+                    if (layoutDirection == LayoutDirection.Ltr) {
+                        layoutWidth - FabSpacing.roundToPx() - fabWidth
+                    } else {
+                        FabSpacing.roundToPx()
+                    }
+                }
+                else -> (layoutWidth - fabWidth) / 2
             }
 
-            val bottomBarPlaceables = subcompose(ScaffoldLayoutContent.BottomBar) {
-                CompositionLocalProvider(
-                    LocalFabPlacement provides fabPlacement,
-                    content = bottomBar,
-                )
-            }.fastMap { it.measure(looseConstraints) }
-
-            val bottomBarHeight = bottomBarPlaceables
-                .fastMaxBy { it.height }
-                ?.height
-                ?.takeIf { it != 0 }
-            val fabOffsetFromBottom = fabPlacement?.let {
-                max(bottomBarHeight ?: 0, bottomInset) + it.height + FabSpacing.roundToPx()
-            }
+            FabPlacement(
+                left = fabLeftOffset,
+                width = fabWidth,
+                height = fabHeight,
+            )
+        } else {
+            null
+        }
+
+        val bottomBarPlaceables = measurables[8]
+            .fastMap { it.measure(looseConstraints) }
 
-            val snackbarOffsetFromBottom = if (snackbarHeight != 0) {
-                snackbarHeight + (fabOffsetFromBottom ?: max(bottomBarHeight ?: 0, bottomInset))
+        val bottomBarHeight = bottomBarPlaceables.fastMaxBy { it.height }?.height ?: 0
+
+        val fabOffsetFromBottom = fabPlacement?.let {
+            if (fabPosition == FabPosition.EndOverlay) {
+                it.height + FabSpacing.roundToPx() + bottomInsetsHeight
             } else {
-                0
+                // Total height is the bottom bar height + the FAB height + the padding
+                // between the FAB and bottom bar
+                max(bottomBarHeight, bottomInsetsHeight) + it.height + FabSpacing.roundToPx()
             }
+        }
+        val snackbarOffsetFromBottom = if (snackbarHeight != 0) {
+            snackbarHeight + max(
+                fabOffsetFromBottom ?: 0,
+                max(
+                    bottomBarHeight,
+                    bottomInsetsHeight,
+                ),
+            )
+        } else {
+            0
+        }
 
-            val bodyContentPlaceables = subcompose(ScaffoldLayoutContent.MainContent) {
-                val insets = contentWindowInsets.asPaddingValues(this@SubcomposeLayout)
-                val fabOffsetDp = fabOffsetFromBottom?.toDp() ?: 0.dp
-                val bottomBarHeightPx = bottomBarHeight ?: 0
-                val innerPadding = PaddingValues(
-                    top =
-                    if (topBarPlaceables.isEmpty()) {
-                        insets.calculateTopPadding()
-                    } else {
-                        topBarHeight.toDp()
-                    },
-                    bottom = // Tachiyomi: Also take account of fab height when providing inner padding
-                    if (bottomBarPlaceables.isEmpty() || bottomBarHeightPx == 0) {
-                        max(insets.calculateBottomPadding(), fabOffsetDp)
-                    } else {
-                        max(bottomBarHeightPx.toDp(), fabOffsetDp)
-                    },
-                    start = max(
-                        insets.calculateStartPadding((this@SubcomposeLayout).layoutDirection),
-                        startBarWidth.toDp(),
-                    ),
-                    end = insets.calculateEndPadding((this@SubcomposeLayout).layoutDirection),
-                )
-                content(innerPadding)
-            }.fastMap { it.measure(looseConstraints) }
+        // Update the backing value for the content padding of the body content
+        // We do this before measuring or placing the body content
+        topContentPadding = max(topBarHeight, topInsetsHeight).toDp()
+        bottomContentPadding = max(fabOffsetFromBottom ?: 0, max(bottomBarHeight, bottomInsetsHeight)).toDp()
+        startContentPadding = max(startBarWidth, startInsetsWidth).toDp()
+        endContentPadding = endInsetsWidth.toDp()
 
-            // Placing to control drawing order to match default elevation of each placeable
+        val bodyContentPlaceables = measurables[9]
+            .fastMap { it.measure(looseConstraints) }
 
+        layout(layoutWidth, layoutHeight) {
+            // Inset spacers are just for convenient measurement logic, no need to place them
+            // Placing to control drawing order to match default elevation of each placeable
             bodyContentPlaceables.fastForEach {
                 it.place(0, 0)
             }
@@ -299,50 +328,27 @@ private fun ScaffoldLayout(
             }
             snackbarPlaceables.fastForEach {
                 it.place(
-                    snackbarLeft,
+                    (layoutWidth - snackbarWidth) / 2 + when (layoutDirection) {
+                        LayoutDirection.Ltr -> startInsetsWidth
+                        LayoutDirection.Rtl -> endInsetsWidth
+                    },
                     layoutHeight - snackbarOffsetFromBottom,
                 )
             }
             // The bottom bar is always at the bottom of the layout
             bottomBarPlaceables.fastForEach {
-                it.place(0, layoutHeight - (bottomBarHeight ?: 0))
+                it.place(0, layoutHeight - bottomBarHeight)
             }
             // Explicitly not using placeRelative here as `leftOffset` already accounts for RTL
-            fabPlaceables.fastForEach {
-                it.place(fabPlacement?.left ?: 0, layoutHeight - (fabOffsetFromBottom ?: 0))
+            fabPlacement?.let { placement ->
+                fabPlaceables.fastForEach {
+                    it.place(placement.left, layoutHeight - fabOffsetFromBottom!!)
+                }
             }
         }
     }
 }
 
-/**
- * The possible positions for a [FloatingActionButton] attached to a [Scaffold].
- */
-@ExperimentalMaterial3Api
-@JvmInline
-value class FabPosition internal constructor(@Suppress("unused") private val value: Int) {
-    companion object {
-        /**
-         * Position FAB at the bottom of the screen in the center, above the [NavigationBar] (if it
-         * exists)
-         */
-        val Center = FabPosition(0)
-
-        /**
-         * Position FAB at the bottom of the screen at the end, above the [NavigationBar] (if it
-         * exists)
-         */
-        val End = FabPosition(1)
-    }
-
-    override fun toString(): String {
-        return when (this) {
-            Center -> "FabPosition.Center"
-            else -> "FabPosition.End"
-        }
-    }
-}
-
 /**
  * Placement information for a [FloatingActionButton] inside a [Scaffold].
  *
@@ -358,12 +364,5 @@ internal class FabPlacement(
     val height: Int,
 )
 
-/**
- * CompositionLocal containing a [FabPlacement] that is used to calculate the FAB bottom offset.
- */
-internal val LocalFabPlacement = staticCompositionLocalOf<FabPlacement?> { null }
-
 // FAB spacing above the bottom bar / bottom of the Scaffold
 private val FabSpacing = 16.dp
-
-private enum class ScaffoldLayoutContent { TopBar, MainContent, Snackbar, Fab, BottomBar, StartBar }