Merge "PriorityNestedScrollConnection: Add flingToScroll [1/2]" into main

9 files changed, 153 insertions, 40 deletions

diff --git a/packages/SystemUI/compose/features/src/com/android/systemui/notifications/ui/composable/NotificationScrimNestedScrollConnection.kt b/packages/SystemUI/compose/features/src/com/android/systemui/notifications/ui/composable/NotificationScrimNestedScrollConnection.kt
index 5cb45e5bd914..94c18cdbef5a 100644
--- a/packages/SystemUI/compose/features/src/com/android/systemui/notifications/ui/composable/NotificationScrimNestedScrollConnection.kt
+++ b/packages/SystemUI/compose/features/src/com/android/systemui/notifications/ui/composable/NotificationScrimNestedScrollConnection.kt
@@ -16,11 +16,13 @@
 
 package com.android.systemui.notifications.ui.composable
 
+import androidx.compose.foundation.gestures.FlingBehavior
 import androidx.compose.foundation.gestures.Orientation
 import androidx.compose.ui.input.nestedscroll.NestedScrollConnection
 import androidx.compose.ui.input.nestedscroll.NestedScrollSource
 import androidx.compose.ui.util.fastCoerceAtLeast
 import androidx.compose.ui.util.fastCoerceAtMost
+import com.android.compose.nestedscroll.OnStopScope
 import com.android.compose.nestedscroll.PriorityNestedScrollConnection
 import com.android.compose.nestedscroll.ScrollController
 
@@ -43,6 +45,7 @@ fun NotificationScrimNestedScrollConnection(
     isCurrentGestureOverscroll: () -> Boolean,
     onStart: (Float) -> Unit = {},
     onStop: (Float) -> Unit = {},
+    flingBehavior: FlingBehavior,
 ): PriorityNestedScrollConnection {
     return PriorityNestedScrollConnection(
         orientation = Orientation.Vertical,
@@ -77,8 +80,9 @@ fun NotificationScrimNestedScrollConnection(
                     return amountConsumed
                 }
 
-                override suspend fun onStop(initialVelocity: Float): Float {
-                    onStop(initialVelocity)
+                override suspend fun OnStopScope.onStop(initialVelocity: Float): Float {
+                    val consumedByScroll = flingToScroll(initialVelocity, flingBehavior)
+                    onStop(initialVelocity - consumedByScroll)
                     if (scrimOffset() < minScrimOffset()) {
                         animateScrimOffset(minScrimOffset())
                     }
diff --git a/packages/SystemUI/compose/features/src/com/android/systemui/notifications/ui/composable/NotificationStackNestedScrollConnection.kt b/packages/SystemUI/compose/features/src/com/android/systemui/notifications/ui/composable/NotificationStackNestedScrollConnection.kt
index e1b74a968caa..d8abfd7a4b94 100644
--- a/packages/SystemUI/compose/features/src/com/android/systemui/notifications/ui/composable/NotificationStackNestedScrollConnection.kt
+++ b/packages/SystemUI/compose/features/src/com/android/systemui/notifications/ui/composable/NotificationStackNestedScrollConnection.kt
@@ -18,7 +18,9 @@ package com.android.systemui.notifications.ui.composable
 
 import androidx.compose.animation.core.Animatable
 import androidx.compose.animation.core.tween
+import androidx.compose.foundation.gestures.FlingBehavior
 import androidx.compose.foundation.gestures.Orientation
+import androidx.compose.foundation.gestures.ScrollableDefaults
 import androidx.compose.foundation.layout.offset
 import androidx.compose.runtime.Composable
 import androidx.compose.runtime.remember
@@ -30,6 +32,7 @@ import androidx.compose.ui.platform.LocalDensity
 import androidx.compose.ui.unit.IntOffset
 import androidx.compose.ui.unit.dp
 import androidx.compose.ui.util.fastCoerceAtLeast
+import com.android.compose.nestedscroll.OnStopScope
 import com.android.compose.nestedscroll.PriorityNestedScrollConnection
 import com.android.compose.nestedscroll.ScrollController
 import kotlin.math.max
@@ -46,32 +49,35 @@ fun Modifier.stackVerticalOverscroll(
     val screenHeight =
         with(LocalDensity.current) { LocalConfiguration.current.screenHeightDp.dp.toPx() }
     val overscrollOffset = remember { Animatable(0f) }
-    val stackNestedScrollConnection = remember {
-        NotificationStackNestedScrollConnection(
-            stackOffset = { overscrollOffset.value },
-            canScrollForward = canScrollForward,
-            onScroll = { offsetAvailable ->
-                coroutineScope.launch {
-                    val maxProgress = screenHeight * 0.2f
-                    val tilt = 3f
-                    var offset =
-                        overscrollOffset.value +
-                            maxProgress * tanh(x = offsetAvailable / (maxProgress * tilt))
-                    offset = max(offset, -1f * maxProgress)
-                    overscrollOffset.snapTo(offset)
-                }
-            },
-            onStop = { velocityAvailable ->
-                coroutineScope.launch {
-                    overscrollOffset.animateTo(
-                        targetValue = 0f,
-                        initialVelocity = velocityAvailable,
-                        animationSpec = tween(),
-                    )
-                }
-            },
-        )
-    }
+    val flingBehavior = ScrollableDefaults.flingBehavior()
+    val stackNestedScrollConnection =
+        remember(flingBehavior) {
+            NotificationStackNestedScrollConnection(
+                stackOffset = { overscrollOffset.value },
+                canScrollForward = canScrollForward,
+                onScroll = { offsetAvailable ->
+                    coroutineScope.launch {
+                        val maxProgress = screenHeight * 0.2f
+                        val tilt = 3f
+                        var offset =
+                            overscrollOffset.value +
+                                maxProgress * tanh(x = offsetAvailable / (maxProgress * tilt))
+                        offset = max(offset, -1f * maxProgress)
+                        overscrollOffset.snapTo(offset)
+                    }
+                },
+                onStop = { velocityAvailable ->
+                    coroutineScope.launch {
+                        overscrollOffset.animateTo(
+                            targetValue = 0f,
+                            initialVelocity = velocityAvailable,
+                            animationSpec = tween(),
+                        )
+                    }
+                },
+                flingBehavior = flingBehavior,
+            )
+        }
 
     return this.then(
         Modifier.nestedScroll(stackNestedScrollConnection).offset {
@@ -86,6 +92,7 @@ fun NotificationStackNestedScrollConnection(
     onStart: (Float) -> Unit = {},
     onScroll: (Float) -> Unit,
     onStop: (Float) -> Unit = {},
+    flingBehavior: FlingBehavior,
 ): PriorityNestedScrollConnection {
     return PriorityNestedScrollConnection(
         orientation = Orientation.Vertical,
@@ -106,8 +113,9 @@ fun NotificationStackNestedScrollConnection(
                     return consumed
                 }
 
-                override suspend fun onStop(initialVelocity: Float): Float {
-                    onStop(initialVelocity)
+                override suspend fun OnStopScope.onStop(initialVelocity: Float): Float {
+                    val consumedByScroll = flingToScroll(initialVelocity, flingBehavior)
+                    onStop(initialVelocity - consumedByScroll)
                     return initialVelocity
                 }
 
diff --git a/packages/SystemUI/compose/features/src/com/android/systemui/notifications/ui/composable/Notifications.kt b/packages/SystemUI/compose/features/src/com/android/systemui/notifications/ui/composable/Notifications.kt
index 4fa1984661da..ae273d8e2ad9 100644
--- a/packages/SystemUI/compose/features/src/com/android/systemui/notifications/ui/composable/Notifications.kt
+++ b/packages/SystemUI/compose/features/src/com/android/systemui/notifications/ui/composable/Notifications.kt
@@ -25,6 +25,7 @@ import androidx.compose.foundation.ScrollState
 import androidx.compose.foundation.background
 import androidx.compose.foundation.clickable
 import androidx.compose.foundation.gestures.Orientation
+import androidx.compose.foundation.gestures.ScrollableDefaults
 import androidx.compose.foundation.gestures.animateScrollBy
 import androidx.compose.foundation.gestures.rememberScrollableState
 import androidx.compose.foundation.gestures.scrollBy
@@ -451,12 +452,14 @@ fun SceneScope.NotificationScrollingStack(
         }
     }
 
+    val flingBehavior = ScrollableDefaults.flingBehavior()
     val scrimNestedScrollConnection =
         shadeSession.rememberSession(
             scrimOffset,
             maxScrimTop,
             minScrimTop,
             isCurrentGestureOverscroll,
+            flingBehavior,
         ) {
             NotificationScrimNestedScrollConnection(
                 scrimOffset = { scrimOffset.value },
@@ -469,6 +472,7 @@ fun SceneScope.NotificationScrollingStack(
                 contentHeight = { stackHeight.intValue.toFloat() },
                 minVisibleScrimHeight = minVisibleScrimHeight,
                 isCurrentGestureOverscroll = { isCurrentGestureOverscroll.value },
+                flingBehavior = flingBehavior,
             )
         }
 
diff --git a/packages/SystemUI/compose/scene/src/com/android/compose/animation/scene/DraggableHandler.kt b/packages/SystemUI/compose/scene/src/com/android/compose/animation/scene/DraggableHandler.kt
index 7c7202a5c7f2..7872ffad6cec 100644
--- a/packages/SystemUI/compose/scene/src/com/android/compose/animation/scene/DraggableHandler.kt
+++ b/packages/SystemUI/compose/scene/src/com/android/compose/animation/scene/DraggableHandler.kt
@@ -27,6 +27,7 @@ import androidx.compose.ui.util.fastCoerceIn
 import com.android.compose.animation.scene.content.Content
 import com.android.compose.animation.scene.content.state.TransitionState
 import com.android.compose.animation.scene.content.state.TransitionState.HasOverscrollProperties.Companion.DistanceUnspecified
+import com.android.compose.nestedscroll.OnStopScope
 import com.android.compose.nestedscroll.PriorityNestedScrollConnection
 import com.android.compose.nestedscroll.ScrollController
 import kotlin.math.absoluteValue
@@ -749,7 +750,7 @@ private fun scrollController(
             return dragController.onDrag(delta = deltaScroll)
         }
 
-        override suspend fun onStop(initialVelocity: Float): Float {
+        override suspend fun OnStopScope.onStop(initialVelocity: Float): Float {
             return dragController
                 .onStop(velocity = initialVelocity, canChangeContent = canChangeScene)
                 .invoke()
diff --git a/packages/SystemUI/compose/scene/src/com/android/compose/nestedscroll/LargeTopAppBarNestedScrollConnection.kt b/packages/SystemUI/compose/scene/src/com/android/compose/nestedscroll/LargeTopAppBarNestedScrollConnection.kt
index 255da31719f3..a5be4dc195bc 100644
--- a/packages/SystemUI/compose/scene/src/com/android/compose/nestedscroll/LargeTopAppBarNestedScrollConnection.kt
+++ b/packages/SystemUI/compose/scene/src/com/android/compose/nestedscroll/LargeTopAppBarNestedScrollConnection.kt
@@ -16,6 +16,7 @@
 
 package com.android.compose.nestedscroll
 
+import androidx.compose.foundation.gestures.FlingBehavior
 import androidx.compose.foundation.gestures.Orientation
 import androidx.compose.ui.input.nestedscroll.NestedScrollConnection
 import androidx.compose.ui.input.nestedscroll.NestedScrollSource
@@ -41,6 +42,7 @@ fun LargeTopAppBarNestedScrollConnection(
     onHeightChanged: (Float) -> Unit,
     minHeight: () -> Float,
     maxHeight: () -> Float,
+    flingBehavior: FlingBehavior,
 ): PriorityNestedScrollConnection {
     return PriorityNestedScrollConnection(
         orientation = Orientation.Vertical,
@@ -55,7 +57,15 @@ fun LargeTopAppBarNestedScrollConnection(
             offsetAvailable > 0 && height() < maxHeight()
         },
         canStartPostFling = { false },
-        onStart = { LargeTopAppBarScrollController(height, maxHeight, minHeight, onHeightChanged) },
+        onStart = {
+            LargeTopAppBarScrollController(
+                height = height,
+                maxHeight = maxHeight,
+                minHeight = minHeight,
+                onHeightChanged = onHeightChanged,
+                flingBehavior = flingBehavior,
+            )
+        },
     )
 }
 
@@ -64,6 +74,7 @@ private class LargeTopAppBarScrollController(
     val maxHeight: () -> Float,
     val minHeight: () -> Float,
     val onHeightChanged: (Float) -> Unit,
+    val flingBehavior: FlingBehavior,
 ) : ScrollController {
     override fun onScroll(deltaScroll: Float, source: NestedScrollSource): Float {
         val currentHeight = height()
@@ -79,9 +90,8 @@ private class LargeTopAppBarScrollController(
         return amountConsumed
     }
 
-    override suspend fun onStop(initialVelocity: Float): Float {
-        // Don't consume the velocity on pre/post fling
-        return 0f
+    override suspend fun OnStopScope.onStop(initialVelocity: Float): Float {
+        return flingToScroll(initialVelocity, flingBehavior)
     }
 
     override fun onCancel() {
diff --git a/packages/SystemUI/compose/scene/src/com/android/compose/nestedscroll/PriorityNestedScrollConnection.kt b/packages/SystemUI/compose/scene/src/com/android/compose/nestedscroll/PriorityNestedScrollConnection.kt
index ca44a5c21cab..e924ebfd2a8d 100644
--- a/packages/SystemUI/compose/scene/src/com/android/compose/nestedscroll/PriorityNestedScrollConnection.kt
+++ b/packages/SystemUI/compose/scene/src/com/android/compose/nestedscroll/PriorityNestedScrollConnection.kt
@@ -16,7 +16,9 @@
 
 package com.android.compose.nestedscroll
 
+import androidx.compose.foundation.gestures.FlingBehavior
 import androidx.compose.foundation.gestures.Orientation
+import androidx.compose.foundation.gestures.ScrollScope
 import androidx.compose.ui.geometry.Offset
 import androidx.compose.ui.input.nestedscroll.NestedScrollConnection
 import androidx.compose.ui.input.nestedscroll.NestedScrollSource
@@ -83,7 +85,16 @@ interface ScrollController {
      * @param initialVelocity The initial velocity of the scroll when stopping.
      * @return The consumed [initialVelocity] when the animation completes.
      */
-    suspend fun onStop(initialVelocity: Float): Float
+    suspend fun OnStopScope.onStop(initialVelocity: Float): Float
+}
+
+interface OnStopScope {
+    /**
+     * Emits scroll events by using the [initialVelocity] and the [FlingBehavior].
+     *
+     * @return consumed velocity
+     */
+    suspend fun flingToScroll(initialVelocity: Float, flingBehavior: FlingBehavior): Float
 }
 
 /**
@@ -307,7 +318,11 @@ class PriorityNestedScrollConnection(
         val controller = requireController(isStopping = false)
         return coroutineScope {
             try {
-                async { controller.onStop(velocity) }
+                async {
+                        with(controller) {
+                            OnStopScopeImpl(controller = controller).onStop(velocity)
+                        }
+                    }
                     // Allows others to interrupt the job.
                     .also { stoppingJob = it }
                     // Note: this can be cancelled by [interruptStopping]
@@ -336,3 +351,19 @@ class PriorityNestedScrollConnection(
         offsetScrolledBeforePriorityMode = 0f
     }
 }
+
+private class OnStopScopeImpl(private val controller: ScrollController) : OnStopScope {
+    override suspend fun flingToScroll(
+        initialVelocity: Float,
+        flingBehavior: FlingBehavior,
+    ): Float {
+        return with(flingBehavior) {
+            object : ScrollScope {
+                    override fun scrollBy(pixels: Float): Float {
+                        return controller.onScroll(pixels, NestedScrollSource.SideEffect)
+                    }
+                }
+                .performFling(initialVelocity)
+        }
+    }
+}
diff --git a/packages/SystemUI/compose/scene/tests/src/com/android/compose/nestedscroll/LargeTopAppBarNestedScrollConnectionTest.kt b/packages/SystemUI/compose/scene/tests/src/com/android/compose/nestedscroll/LargeTopAppBarNestedScrollConnectionTest.kt
index a406e13904f5..e27f9b52153d 100644
--- a/packages/SystemUI/compose/scene/tests/src/com/android/compose/nestedscroll/LargeTopAppBarNestedScrollConnectionTest.kt
+++ b/packages/SystemUI/compose/scene/tests/src/com/android/compose/nestedscroll/LargeTopAppBarNestedScrollConnectionTest.kt
@@ -16,6 +16,8 @@
 
 package com.android.compose.nestedscroll
 
+import androidx.compose.foundation.gestures.FlingBehavior
+import androidx.compose.foundation.gestures.ScrollScope
 import androidx.compose.ui.geometry.Offset
 import androidx.compose.ui.input.nestedscroll.NestedScrollConnection
 import androidx.compose.ui.input.nestedscroll.NestedScrollSource
@@ -29,6 +31,13 @@ class LargeTopAppBarNestedScrollConnectionTest(testCase: TestCase) {
     val scrollSource = testCase.scrollSource
 
     private var height = 0f
+    private val customFlingBehavior =
+        object : FlingBehavior {
+            override suspend fun ScrollScope.performFling(initialVelocity: Float): Float {
+                scrollBy(initialVelocity)
+                return initialVelocity / 2f
+            }
+        }
 
     private fun buildScrollConnection(heightRange: ClosedFloatingPointRange<Float>) =
         LargeTopAppBarNestedScrollConnection(
@@ -36,6 +45,7 @@ class LargeTopAppBarNestedScrollConnectionTest(testCase: TestCase) {
             onHeightChanged = { height = it },
             minHeight = { heightRange.start },
             maxHeight = { heightRange.endInclusive },
+            flingBehavior = customFlingBehavior,
         )
 
     private fun NestedScrollConnection.scroll(
diff --git a/packages/SystemUI/compose/scene/tests/src/com/android/compose/nestedscroll/PriorityNestedScrollConnectionTest.kt b/packages/SystemUI/compose/scene/tests/src/com/android/compose/nestedscroll/PriorityNestedScrollConnectionTest.kt
index 0364cdc4166e..54428404bd0c 100644
--- a/packages/SystemUI/compose/scene/tests/src/com/android/compose/nestedscroll/PriorityNestedScrollConnectionTest.kt
+++ b/packages/SystemUI/compose/scene/tests/src/com/android/compose/nestedscroll/PriorityNestedScrollConnectionTest.kt
@@ -18,12 +18,15 @@
 
 package com.android.compose.nestedscroll
 
+import androidx.compose.foundation.gestures.FlingBehavior
 import androidx.compose.foundation.gestures.Orientation
+import androidx.compose.foundation.gestures.ScrollScope
 import androidx.compose.ui.geometry.Offset
 import androidx.compose.ui.input.nestedscroll.NestedScrollSource
 import androidx.compose.ui.input.nestedscroll.NestedScrollSource.Companion.UserInput
 import androidx.compose.ui.unit.Velocity
 import androidx.test.ext.junit.runners.AndroidJUnit4
+import com.android.compose.test.runMonotonicClockTest
 import com.google.common.truth.Truth.assertThat
 import kotlinx.coroutines.ExperimentalCoroutinesApi
 import kotlinx.coroutines.test.runTest
@@ -41,7 +44,16 @@ class PriorityNestedScrollConnectionTest {
     private var consumeScroll = true
     private var lastStop: Float? = null
     private var isCancelled: Boolean = false
-    private var consumeStop = true
+    private var onStopConsumeFlingToScroll = false
+    private var onStopConsumeAll = true
+
+    private val customFlingBehavior =
+        object : FlingBehavior {
+            override suspend fun ScrollScope.performFling(initialVelocity: Float): Float {
+                scrollBy(initialVelocity)
+                return initialVelocity / 2f
+            }
+        }
 
     private val scrollConnection =
         PriorityNestedScrollConnection(
@@ -57,9 +69,16 @@ class PriorityNestedScrollConnectionTest {
                         return if (consumeScroll) deltaScroll else 0f
                     }
 
-                    override suspend fun onStop(initialVelocity: Float): Float {
+                    override suspend fun OnStopScope.onStop(initialVelocity: Float): Float {
                         lastStop = initialVelocity
-                        return if (consumeStop) initialVelocity else 0f
+                        var velocityConsumed = 0f
+                        if (onStopConsumeFlingToScroll) {
+                            velocityConsumed = flingToScroll(initialVelocity, customFlingBehavior)
+                        }
+                        if (onStopConsumeAll) {
+                            velocityConsumed = initialVelocity
+                        }
+                        return velocityConsumed
                     }
 
                     override fun onCancel() {
@@ -178,6 +197,22 @@ class PriorityNestedScrollConnectionTest {
     }
 
     @Test
+    fun onStopScrollUsingFlingToScroll() = runMonotonicClockTest {
+        startPriorityModePostScroll()
+        onStopConsumeFlingToScroll = true
+        onStopConsumeAll = false
+        lastScroll = Float.NaN
+
+        val consumed = scrollConnection.onPreFling(available = Velocity(2f, 2f))
+
+        assertThat(lastStop).isEqualTo(2f)
+        // flingToScroll should try to scroll the content, customFlingBehavior uses the velocity.
+        assertThat(lastScroll).isEqualTo(2f)
+        // customFlingBehavior returns half of the vertical velocity.
+        assertThat(consumed).isEqualTo(Velocity(0f, 1f))
+    }
+
+    @Test
     fun ifCannotStopOnPreFling_shouldStopOnPostFling() = runTest {
         startPriorityModePostScroll()
         canStopOnPreFling = false
diff --git a/packages/SystemUI/multivalentTests/src/com/android/systemui/statusbar/notification/NotificationScrimNestedScrollConnectionTest.kt b/packages/SystemUI/multivalentTests/src/com/android/systemui/statusbar/notification/NotificationScrimNestedScrollConnectionTest.kt
index 75479ad35725..60b95ad632e1 100644
--- a/packages/SystemUI/multivalentTests/src/com/android/systemui/statusbar/notification/NotificationScrimNestedScrollConnectionTest.kt
+++ b/packages/SystemUI/multivalentTests/src/com/android/systemui/statusbar/notification/NotificationScrimNestedScrollConnectionTest.kt
@@ -16,6 +16,8 @@
 
 package com.android.systemui.statusbar.notification
 
+import androidx.compose.foundation.gestures.FlingBehavior
+import androidx.compose.foundation.gestures.ScrollScope
 import androidx.compose.ui.geometry.Offset
 import androidx.compose.ui.input.nestedscroll.NestedScrollSource.Companion.UserInput
 import androidx.test.ext.junit.runners.AndroidJUnit4
@@ -35,6 +37,13 @@ class NotificationScrimNestedScrollConnectionTest : SysuiTestCase() {
     private var scrimOffset = 0f
     private var contentHeight = 0f
     private var isCurrentGestureOverscroll = false
+    private val customFlingBehavior =
+        object : FlingBehavior {
+            override suspend fun ScrollScope.performFling(initialVelocity: Float): Float {
+                scrollBy(initialVelocity)
+                return initialVelocity / 2f
+            }
+        }
 
     private val scrollConnection =
         NotificationScrimNestedScrollConnection(
@@ -51,6 +60,7 @@ class NotificationScrimNestedScrollConnectionTest : SysuiTestCase() {
                 wasStarted = true
                 isStarted = false
             },
+            flingBehavior = customFlingBehavior,
         )
 
     @Test