Merge changes from topic "stl-dynamic-distance" into main

* changes:
  Move UserActionDistance to TransitionSpec
  Make it possible to compute the swipe distance lazily

packages/SystemUI/compose/features/src/com/android/systemui/scene/ui/composable/ComposeAwareExtensions.kt

@@ -16,9 +16,6 @@
 
 package com.android.systemui.scene.ui.composable
 
-import androidx.compose.foundation.gestures.Orientation
-import androidx.compose.ui.unit.Density
-import androidx.compose.ui.unit.IntSize
 import com.android.compose.animation.scene.Back
 import com.android.compose.animation.scene.Edge as ComposeAwareEdge
 import com.android.compose.animation.scene.SceneKey as ComposeAwareSceneKey
@@ -26,14 +23,12 @@ import com.android.compose.animation.scene.Swipe
 import com.android.compose.animation.scene.SwipeDirection
 import com.android.compose.animation.scene.TransitionKey as ComposeAwareTransitionKey
 import com.android.compose.animation.scene.UserAction as ComposeAwareUserAction
-import com.android.compose.animation.scene.UserActionDistance as ComposeAwareUserActionDistance
 import com.android.compose.animation.scene.UserActionResult as ComposeAwareUserActionResult
 import com.android.systemui.scene.shared.model.Direction
 import com.android.systemui.scene.shared.model.Edge
 import com.android.systemui.scene.shared.model.SceneKey
 import com.android.systemui.scene.shared.model.TransitionKey
 import com.android.systemui.scene.shared.model.UserAction
-import com.android.systemui.scene.shared.model.UserActionDistance
 import com.android.systemui.scene.shared.model.UserActionResult
 
 // TODO(b/293899074): remove this file once we can use the types from SceneTransitionLayout.
@@ -82,22 +77,5 @@ fun UserActionResult.asComposeAware(): ComposeAwareUserActionResult {
     return ComposeAwareUserActionResult(
         toScene = composeUnaware.toScene.asComposeAware(),
         transitionKey = composeUnaware.transitionKey?.asComposeAware(),
-        distance = composeUnaware.distance?.asComposeAware(),
     )
 }
-
-fun UserActionDistance.asComposeAware(): ComposeAwareUserActionDistance {
-    val composeUnware = this
-    return object : ComposeAwareUserActionDistance {
-        override fun Density.absoluteDistance(
-            fromSceneSize: IntSize,
-            orientation: Orientation,
-        ): Float {
-            return composeUnware.absoluteDistance(
-                fromSceneWidth = fromSceneSize.width,
-                fromSceneHeight = fromSceneSize.height,
-                isHorizontal = orientation == Orientation.Horizontal,
-            )
-        }
-    }
-}

packages/SystemUI/compose/scene/src/com/android/compose/animation/scene/SceneGestureHandler.kt

@@ -27,7 +27,6 @@ import androidx.compose.runtime.mutableFloatStateOf
 import androidx.compose.runtime.mutableStateOf
 import androidx.compose.runtime.setValue
 import androidx.compose.ui.geometry.Offset
-import androidx.compose.ui.unit.Density
 import androidx.compose.ui.unit.IntSize
 import androidx.compose.ui.unit.dp
 import androidx.compose.ui.unit.round
@@ -56,14 +55,17 @@ internal class SceneGestureHandler(
         if (isDrivingTransition || force) {
             layoutState.startTransition(newTransition, newTransition.key)
 
-            // Initialize SwipeTransition.swipeSpec. Note that this must be called right after
-            // layoutState.startTransition() is called, because it computes the
-            // layoutState.transformationSpec().
+            // Initialize SwipeTransition.transformationSpec and .swipeSpec. Note that this must be
+            // called right after layoutState.startTransition() is called, because it computes the
+            // current layoutState.transformationSpec().
+            val transformationSpec = layoutState.transformationSpec
+            newTransition.transformationSpec = transformationSpec
             newTransition.swipeSpec =
-                layoutState.transformationSpec.swipeSpec ?: layoutState.transitions.defaultSwipeSpec
+                transformationSpec.swipeSpec ?: layoutState.transitions.defaultSwipeSpec
         } else {
-            // We were not driving the transition and we don't force the update, so the spec won't
-            // be used and it doesn't matter which one we set here.
+            // We were not driving the transition and we don't force the update, so the specs won't
+            // be used and it doesn't matter which ones we set here.
+            newTransition.transformationSpec = TransformationSpec.Empty
             newTransition.swipeSpec = SceneTransitions.DefaultSwipeSpec
         }
 
@@ -285,16 +287,21 @@ internal class SceneGestureHandler(
     ): Pair<Scene, Float> {
         val toScene = swipeTransition._toScene
         val fromScene = swipeTransition._fromScene
-        val absoluteDistance = swipeTransition.distance.absoluteValue
+        val distance = swipeTransition.distance()
 
-        // If the swipe was not committed, don't do anything.
-        if (swipeTransition._currentScene != toScene) {
+        // If the swipe was not committed or if the swipe distance is not computed yet, don't do
+        // anything.
+        if (
+            swipeTransition._currentScene != toScene ||
+                distance == SwipeTransition.DistanceUnspecified
+        ) {
             return fromScene to 0f
         }
 
         // If the offset is past the distance then let's change fromScene so that the user can swipe
         // to the next screen or go back to the previous one.
         val offset = swipeTransition.dragOffset
+        val absoluteDistance = distance.absoluteValue
         return if (offset <= -absoluteDistance && swipes!!.upOrLeftResult?.toScene == toScene.key) {
             toScene to absoluteDistance
         } else if (
@@ -347,16 +354,17 @@ internal class SceneGestureHandler(
 
             // Compute the destination scene (and therefore offset) to settle in.
             val offset = swipeTransition.dragOffset
-            val distance = swipeTransition.distance
+            val distance = swipeTransition.distance()
             var targetScene: Scene
             var targetOffset: Float
             if (
-                shouldCommitSwipe(
-                    offset,
-                    distance,
-                    velocity,
-                    wasCommitted = swipeTransition._currentScene == toScene,
-                )
+                distance != SwipeTransition.DistanceUnspecified &&
+                    shouldCommitSwipe(
+                        offset,
+                        distance,
+                        velocity,
+                        wasCommitted = swipeTransition._currentScene == toScene,
+                    )
             ) {
                 targetScene = toScene
                 targetOffset = distance
@@ -372,7 +380,15 @@ internal class SceneGestureHandler(
                 // We wanted to change to a new scene but we are not allowed to, so we animate back
                 // to the current scene.
                 targetScene = swipeTransition._currentScene
-                targetOffset = if (targetScene == fromScene) 0f else distance
+                targetOffset =
+                    if (targetScene == fromScene) {
+                        0f
+                    } else {
+                        check(distance != SwipeTransition.DistanceUnspecified) {
+                            "distance is equal to ${SwipeTransition.DistanceUnspecified}"
+                        }
+                        distance
+                    }
             }
 
             animateTo(targetScene = targetScene, targetOffset = targetOffset)
@@ -459,22 +475,20 @@ private fun SwipeTransition(
 ): SwipeTransition {
     val upOrLeftResult = swipes.upOrLeftResult
     val downOrRightResult = swipes.downOrRightResult
-    val userActionDistance = result.distance ?: DefaultSwipeDistance
-    val absoluteDistance =
-        with(userActionDistance) {
-            layoutImpl.density.absoluteDistance(fromScene.targetSize, orientation)
+    val isUpOrLeft =
+        when (result) {
+            upOrLeftResult -> true
+            downOrRightResult -> false
+            else -> error("Unknown result $result ($upOrLeftResult $downOrRightResult)")
         }
 
     return SwipeTransition(
         key = result.transitionKey,
         _fromScene = fromScene,
         _toScene = layoutImpl.scene(result.toScene),
-        distance =
-            when (result) {
-                upOrLeftResult -> -absoluteDistance
-                downOrRightResult -> absoluteDistance
-                else -> error("Unknown result $result ($upOrLeftResult $downOrRightResult)")
-            },
+        userActionDistanceScope = layoutImpl.userActionDistanceScope,
+        orientation = orientation,
+        isUpOrLeft = isUpOrLeft,
     )
 }
 
@@ -482,11 +496,9 @@ private class SwipeTransition(
     val key: TransitionKey?,
     val _fromScene: Scene,
     val _toScene: Scene,
-    /**
-     * The signed distance between [fromScene] and [toScene]. It is negative if [fromScene] is above
-     * or to the left of [toScene]
-     */
-    val distance: Float,
+    private val userActionDistanceScope: UserActionDistanceScope,
+    private val orientation: Orientation,
+    private val isUpOrLeft: Boolean,
 ) : TransitionState.Transition(_fromScene.key, _toScene.key) {
     var _currentScene by mutableStateOf(_fromScene)
     override val currentScene: SceneKey
@@ -494,7 +506,16 @@ private class SwipeTransition(
 
     override val progress: Float
         get() {
+            // Important: If we are going to return early because distance is equal to 0, we should
+            // still make sure we read the offset before returning so that the calling code still
+            // subscribes to the offset value.
             val offset = if (isAnimatingOffset) offsetAnimatable.value else dragOffset
+
+            val distance = distance()
+            if (distance == DistanceUnspecified) {
+                return 0f
+            }
+
             return offset / distance
         }
 
@@ -518,9 +539,50 @@ private class SwipeTransition(
     /** Job to check that there is at most one offset animation in progress. */
     private var offsetAnimationJob: Job? = null
 
+    /**
+     * The [TransformationSpecImpl] associated to this transition.
+     *
+     * Note: This is lateinit because this [SwipeTransition] is needed by
+     * [BaseSceneTransitionLayoutState] to compute the [TransitionSpec], and it will be set right
+     * after [BaseSceneTransitionLayoutState.startTransition] is called with this transition.
+     */
+    lateinit var transformationSpec: TransformationSpecImpl
+
     /** The spec to use when animating this transition to either [fromScene] or [toScene]. */
     lateinit var swipeSpec: SpringSpec<Float>
 
+    private var lastDistance = DistanceUnspecified
+
+    /**
+     * The signed distance between [fromScene] and [toScene]. It is negative if [fromScene] is above
+     * or to the left of [toScene].
+     *
+     * Note that this distance can be equal to [DistanceUnspecified] during the first frame of a
+     * transition when the distance depends on the size or position of an element that is composed
+     * in the scene we are going to.
+     */
+    fun distance(): Float {
+        if (lastDistance != DistanceUnspecified) {
+            return lastDistance
+        }
+
+        val absoluteDistance =
+            with(transformationSpec.distance ?: DefaultSwipeDistance) {
+                userActionDistanceScope.absoluteDistance(
+                    _fromScene.targetSize,
+                    orientation,
+                )
+            }
+
+        if (absoluteDistance <= 0f) {
+            return DistanceUnspecified
+        }
+
+        val distance = if (isUpOrLeft) -absoluteDistance else absoluteDistance
+        lastDistance = distance
+        return distance
+    }
+
     /** Ends any previous [offsetAnimationJob] and runs the new [job]. */
     private fun startOffsetAnimation(job: () -> Job) {
         cancelOffsetAnimation()
@@ -563,6 +625,7 @@ private class SwipeTransition(
         }
         isAnimatingOffset = true
 
+        val animationSpec = transformationSpec
         offsetAnimatable.animateTo(
             targetValue = targetOffset,
             animationSpec = swipeSpec,
@@ -571,10 +634,14 @@ private class SwipeTransition(
 
         finishOffsetAnimation()
     }
+
+    companion object {
+        const val DistanceUnspecified = 0f
+    }
 }
 
 private object DefaultSwipeDistance : UserActionDistance {
-    override fun Density.absoluteDistance(
+    override fun UserActionDistanceScope.absoluteDistance(
         fromSceneSize: IntSize,
         orientation: Orientation,
     ): Float {

packages/SystemUI/compose/scene/src/com/android/compose/animation/scene/SceneTransitionLayout.kt

@@ -25,6 +25,7 @@ import androidx.compose.runtime.remember
 import androidx.compose.runtime.rememberCoroutineScope
 import androidx.compose.ui.Alignment
 import androidx.compose.ui.Modifier
+import androidx.compose.ui.geometry.Offset
 import androidx.compose.ui.input.nestedscroll.NestedScrollConnection
 import androidx.compose.ui.platform.LocalDensity
 import androidx.compose.ui.unit.Density
@@ -394,36 +395,52 @@ class UserActionResult(
     /** The scene we should be transitioning to during the [UserAction]. */
     val toScene: SceneKey,
 
-    /**
-     * The distance the action takes to animate from 0% to 100%.
-     *
-     * If `null`, a default distance will be used that depends on the [UserAction] performed.
-     */
-    val distance: UserActionDistance? = null,
-
     /** The key of the transition that should be used. */
     val transitionKey: TransitionKey? = null,
-) {
-    constructor(
-        toScene: SceneKey,
-        distance: Dp,
-        transitionKey: TransitionKey? = null,
-    ) : this(toScene, FixedDistance(distance), transitionKey)
-}
+)
 
 interface UserActionDistance {
     /**
      * Return the **absolute** distance of the user action given the size of the scene we are
      * animating from and the [orientation].
+     *
+     * Note: This function will be called for each drag event until it returns a value > 0f. This
+     * for instance allows you to return 0f or a negative value until the first layout pass of a
+     * scene, so that you can use the size and position of elements in the scene we are
+     * transitioning to when computing this absolute distance.
      */
-    fun Density.absoluteDistance(fromSceneSize: IntSize, orientation: Orientation): Float
+    fun UserActionDistanceScope.absoluteDistance(
+        fromSceneSize: IntSize,
+        orientation: Orientation
+    ): Float
+}
+
+interface UserActionDistanceScope : Density {
+    /**
+     * Return the *target* size of [this] element in the given [scene], i.e. the size of the element
+     * when idle, or `null` if the element is not composed and measured in that scene (yet).
+     */
+    fun ElementKey.targetSize(scene: SceneKey): IntSize?
+
+    /**
+     * Return the *target* offset of [this] element in the given [scene], i.e. the size of the
+     * element when idle, or `null` if the element is not composed and placed in that scene (yet).
+     */
+    fun ElementKey.targetOffset(scene: SceneKey): Offset?
+
+    /**
+     * Return the *target* size of [this] scene, i.e. the size of the scene when idle, or `null` if
+     * the scene was never composed.
+     */
+    fun SceneKey.targetSize(): IntSize?
 }
 
 /** The user action has a fixed [absoluteDistance]. */
-private class FixedDistance(private val distance: Dp) : UserActionDistance {
-    override fun Density.absoluteDistance(fromSceneSize: IntSize, orientation: Orientation): Float {
-        return distance.toPx()
-    }
+class FixedDistance(private val distance: Dp) : UserActionDistance {
+    override fun UserActionDistanceScope.absoluteDistance(
+        fromSceneSize: IntSize,
+        orientation: Orientation,
+    ): Float = distance.toPx()
 }
 
 /**

packages/SystemUI/compose/scene/src/com/android/compose/animation/scene/SceneTransitionLayoutImpl.kt

@@ -96,9 +96,18 @@ internal class SceneTransitionLayoutImpl(
                 ?: mutableMapOf<ValueKey, MutableMap<ElementKey?, SnapshotStateMap<SceneKey, *>>>()
                     .also { _sharedValues = it }
 
+    // TODO(b/317958526): Lazily allocate scene gesture handlers the first time they are needed.
     private val horizontalGestureHandler: SceneGestureHandler
     private val verticalGestureHandler: SceneGestureHandler
 
+    private var _userActionDistanceScope: UserActionDistanceScope? = null
+    internal val userActionDistanceScope: UserActionDistanceScope
+        get() =
+            _userActionDistanceScope
+                ?: UserActionDistanceScopeImpl(layoutImpl = this).also {
+                    _userActionDistanceScope = it
+                }
+
     init {
         updateScenes(builder)
 

packages/SystemUI/compose/scene/src/com/android/compose/animation/scene/SceneTransitions.kt

@@ -163,6 +163,14 @@ interface TransformationSpec {
      */
     val swipeSpec: SpringSpec<Float>?
 
+    /**
+     * The distance it takes for this transition to animate from 0% to 100% when it is driven by a
+     * [UserAction].
+     *
+     * If `null`, a default distance will be used that depends on the [UserAction] performed.
+     */
+    val distance: UserActionDistance?
+
     /** The list of [Transformation] applied to elements during this transition. */
     val transformations: List<Transformation>
 
@@ -171,6 +179,7 @@ interface TransformationSpec {
             TransformationSpecImpl(
                 progressSpec = snap(),
                 swipeSpec = null,
+                distance = null,
                 transformations = emptyList(),
             )
         internal val EmptyProvider = { Empty }
@@ -193,6 +202,7 @@ internal class TransitionSpecImpl(
                 TransformationSpecImpl(
                     progressSpec = reverse.progressSpec,
                     swipeSpec = reverse.swipeSpec,
+                    distance = reverse.distance,
                     transformations = reverse.transformations.map { it.reversed() }
                 )
             }
@@ -209,6 +219,7 @@ internal class TransitionSpecImpl(
 internal class TransformationSpecImpl(
     override val progressSpec: AnimationSpec<Float>,
     override val swipeSpec: SpringSpec<Float>?,
+    override val distance: UserActionDistance?,
     override val transformations: List<Transformation>,
 ) : TransformationSpec {
     private val cache = mutableMapOf<ElementKey, MutableMap<SceneKey, ElementTransformations>>()

packages/SystemUI/compose/scene/src/com/android/compose/animation/scene/TransitionDsl.kt

@@ -90,6 +90,14 @@ interface TransitionBuilder : PropertyTransformationBuilder {
      */
     var swipeSpec: SpringSpec<Float>?
 
+    /**
+     * The distance it takes for this transition to animate from 0% to 100% when it is driven by a
+     * [UserAction].
+     *
+     * If `null`, a default distance will be used that depends on the [UserAction] performed.
+     */
+    var distance: UserActionDistance?
+
     /**
      * Define a progress-based range for the transformations inside [builder].
      *

packages/SystemUI/compose/scene/src/com/android/compose/animation/scene/TransitionDslImpl.kt

@@ -77,6 +77,7 @@ private class SceneTransitionsBuilderImpl : SceneTransitionsBuilder {
             return TransformationSpecImpl(
                 progressSpec = impl.spec,
                 swipeSpec = impl.swipeSpec,
+                distance = impl.distance,
                 transformations = impl.transformations,
             )
         }
@@ -91,6 +92,7 @@ internal class TransitionBuilderImpl : TransitionBuilder {
     val transformations = mutableListOf<Transformation>()
     override var spec: AnimationSpec<Float> = spring(stiffness = Spring.StiffnessLow)
     override var swipeSpec: SpringSpec<Float>? = null
+    override var distance: UserActionDistance? = null
 
     private var range: TransformationRange? = null
     private var reversed = false

packages/SystemUI/compose/scene/src/com/android/compose/animation/scene/UserActionDistanceScopeImpl.kt

+/*
+ * Copyright (C) 2024 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.android.compose.animation.scene
+
+import androidx.compose.ui.geometry.Offset
+import androidx.compose.ui.unit.IntSize
+
+internal class UserActionDistanceScopeImpl(
+    private val layoutImpl: SceneTransitionLayoutImpl,
+) : UserActionDistanceScope {
+    override val density: Float
+        get() = layoutImpl.density.density
+
+    override val fontScale: Float
+        get() = layoutImpl.density.fontScale
+
+    override fun ElementKey.targetSize(scene: SceneKey): IntSize? {
+        return layoutImpl.elements[this]?.sceneStates?.get(scene)?.targetSize.takeIf {
+            it != Element.SizeUnspecified
+        }
+    }
+
+    override fun ElementKey.targetOffset(scene: SceneKey): Offset? {
+        return layoutImpl.elements[this]?.sceneStates?.get(scene)?.targetOffset.takeIf {
+            it != Offset.Unspecified
+        }
+    }
+
+    override fun SceneKey.targetSize(): IntSize? {
+        return layoutImpl.scenes[this]?.targetSize.takeIf { it != IntSize.Zero }
+    }
+}

packages/SystemUI/compose/scene/tests/src/com/android/compose/animation/scene/SwipeToSceneTest.kt

@@ -16,9 +16,11 @@
 
 package com.android.compose.animation.scene
 
+import androidx.compose.foundation.gestures.Orientation
 import androidx.compose.foundation.layout.Box
 import androidx.compose.foundation.layout.Spacer
 import androidx.compose.foundation.layout.fillMaxSize
+import androidx.compose.foundation.layout.offset
 import androidx.compose.foundation.layout.size
 import androidx.compose.runtime.Composable
 import androidx.compose.runtime.getValue
@@ -33,6 +35,7 @@ import androidx.compose.ui.test.onRoot
 import androidx.compose.ui.test.performTouchInput
 import androidx.compose.ui.test.swipeWithVelocity
 import androidx.compose.ui.unit.Density
+import androidx.compose.ui.unit.IntSize
 import androidx.compose.ui.unit.dp
 import androidx.test.ext.junit.runners.AndroidJUnit4
 import com.google.common.truth.Truth.assertThat
@@ -61,8 +64,10 @@ class SwipeToSceneTest {
 
     @get:Rule val rule = createComposeRule()
 
-    private fun layoutState(initialScene: SceneKey = TestScenes.SceneA) =
-        MutableSceneTransitionLayoutState(initialScene, EmptyTestTransitions)
+    private fun layoutState(
+        initialScene: SceneKey = TestScenes.SceneA,
+        transitions: SceneTransitions = EmptyTestTransitions,
+    ) = MutableSceneTransitionLayoutState(initialScene, transitions)
 
     /** The content under test. */
     @Composable
@@ -370,8 +375,16 @@ class SwipeToSceneTest {
         // detected as a drag event.
         var touchSlop = 0f
 
-        val layoutState = layoutState()
         val verticalSwipeDistance = 50.dp
+        val layoutState =
+            layoutState(
+                transitions =
+                    transitions {
+                        from(TestScenes.SceneA, to = TestScenes.SceneB) {
+                            distance = FixedDistance(verticalSwipeDistance)
+                        }
+                    }
+            )
         assertThat(verticalSwipeDistance).isNotEqualTo(LayoutHeight)
 
         rule.setContent {
@@ -383,14 +396,7 @@ class SwipeToSceneTest {
             ) {
                 scene(
                     TestScenes.SceneA,
-                    userActions =
-                        mapOf(
-                            Swipe.Down to
-                                UserActionResult(
-                                    toScene = TestScenes.SceneB,
-                                    distance = verticalSwipeDistance,
-                                )
-                        ),
+                    userActions = mapOf(Swipe.Down to TestScenes.SceneB),
                 ) {
                     Spacer(Modifier.fillMaxSize())
                 }
@@ -548,4 +554,64 @@ class SwipeToSceneTest {
         assertThat(state.isTransitioning(from = TestScenes.SceneA, to = TestScenes.SceneB)).isTrue()
         assertThat(state.transformationSpec.transformations).hasSize(2)
     }
+
+    @Test
+    fun dynamicSwipeDistance() {
+        val swipeDistance =
+            object : UserActionDistance {
+                override fun UserActionDistanceScope.absoluteDistance(
+                    fromSceneSize: IntSize,
+                    orientation: Orientation,
+                ): Float {
+                    // Foo is going to have a vertical offset of 50dp. Let's make the swipe distance
+                    // the difference between the bottom of the scene and the bottom of the element,
+                    // so that we use the offset and size of the element as well as the size of the
+                    // scene.
+                    val fooSize = TestElements.Foo.targetSize(TestScenes.SceneB) ?: return 0f
+                    val fooOffset = TestElements.Foo.targetOffset(TestScenes.SceneB) ?: return 0f
+                    val sceneSize = TestScenes.SceneB.targetSize() ?: return 0f
+                    return sceneSize.height - fooOffset.y - fooSize.height
+                }
+            }
+
+        val state =
+            MutableSceneTransitionLayoutState(
+                TestScenes.SceneA,
+                transitions {
+                    from(TestScenes.SceneA, to = TestScenes.SceneB) { distance = swipeDistance }
+                }
+            )
+
+        val layoutSize = 200.dp
+        val fooYOffset = 50.dp
+        val fooSize = 25.dp
+
+        var touchSlop = 0f
+        rule.setContent {
+            touchSlop = LocalViewConfiguration.current.touchSlop
+
+            SceneTransitionLayout(state, Modifier.size(layoutSize)) {
+                scene(TestScenes.SceneA, userActions = mapOf(Swipe.Up to TestScenes.SceneB)) {
+                    Box(Modifier.fillMaxSize())
+                }
+                scene(TestScenes.SceneB) {
+                    Box(Modifier.fillMaxSize()) {
+                        Box(Modifier.offset(y = fooYOffset).element(TestElements.Foo).size(fooSize))
+                    }
+                }
+            }
+        }
+
+        // Swipe up by half the expected distance to get to 50% progress.
+        val expectedDistance = layoutSize - fooYOffset - fooSize
+        rule.onRoot().performTouchInput {
+            val middle = (layoutSize / 2).toPx()
+            down(Offset(middle, middle))
+            moveBy(Offset(0f, -touchSlop - (expectedDistance / 2f).toPx()), delayMillis = 1_000)
+        }
+
+        rule.waitForIdle()
+        assertThat(state.isTransitioning(from = TestScenes.SceneA, to = TestScenes.SceneB)).isTrue()
+        assertThat(state.currentTransition!!.progress).isWithin(0.01f).of(0.5f)
+    }
 }

packages/SystemUI/src/com/android/systemui/scene/shared/model/UserActionResult.kt

@@ -21,13 +21,6 @@ data class UserActionResult(
     /** The scene we should be transitioning due to the [UserAction]. */
     val toScene: SceneKey,
 
-    /**
-     * The distance the action takes to animate from 0% to 100%.
-     *
-     * If `null`, a default distance will be used depending on the [UserAction] performed.
-     */
-    val distance: UserActionDistance? = null,
-
     /**
      * The key of the transition that should be used, if a specific one should be used.
      *