Merge "NestedScrollToScene communicate desired behavior while scrolling" into main (9ec83fe1) · Commits · e / os / android_frameworks_base

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

+1 −0

Original line number	Diff line number	Diff line
		@@ -64,6 +64,7 @@ internal class DraggableHandlerImpl(
		internal val orientation: Orientation,
		internal val coroutineScope: CoroutineScope,
		) : DraggableHandler {
		internal val nestedScrollKey = Any()
		/** The [DraggableHandler] can only have one active [DragController] at a time. */
		private var dragController: DragControllerImpl? = null

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

+64 −5

Original line number	Diff line number	Diff line
		@@ -18,6 +18,9 @@ package com.android.compose.animation.scene

		import androidx.compose.foundation.gestures.Orientation
		import androidx.compose.ui.Modifier
		import androidx.compose.ui.geometry.Offset
		import androidx.compose.ui.input.nestedscroll.NestedScrollConnection
		import androidx.compose.ui.input.nestedscroll.NestedScrollSource
		import androidx.compose.ui.input.nestedscroll.nestedScrollModifierNode
		import androidx.compose.ui.node.DelegatableNode
		import androidx.compose.ui.node.DelegatingNode
		@@ -122,13 +125,55 @@ private data class NestedScrollToSceneElement(
		}

		private class NestedScrollToSceneNode(
		layoutImpl: SceneTransitionLayoutImpl,
		orientation: Orientation,
		topOrLeftBehavior: NestedScrollBehavior,
		bottomOrRightBehavior: NestedScrollBehavior,
		isExternalOverscrollGesture: () -> Boolean,
		private var layoutImpl: SceneTransitionLayoutImpl,
		private var orientation: Orientation,
		private var topOrLeftBehavior: NestedScrollBehavior,
		private var bottomOrRightBehavior: NestedScrollBehavior,
		private var isExternalOverscrollGesture: () -> Boolean,
		) : DelegatingNode() {
		lateinit var pointersInfoOwner: PointersInfoOwner
		private var scrollBehaviorOwner: ScrollBehaviorOwner? = null

		private fun requireScrollBehaviorOwner(): ScrollBehaviorOwner {
		var behaviorOwner = scrollBehaviorOwner
		if (behaviorOwner == null) {
		behaviorOwner = requireScrollBehaviorOwner(layoutImpl.draggableHandler(orientation))
		scrollBehaviorOwner = behaviorOwner
		}
		return behaviorOwner
		}

		val updateScrollBehaviorsConnection =
		object : NestedScrollConnection {
		/**
		* When using [NestedScrollConnection.onPostScroll], we can specify the desired behavior
		* before our parent components. This gives them the option to override our behavior if
		* they choose.
		*
		* The behavior can be communicated at every scroll gesture to ensure that the hierarchy
		* is respected, even if one of our descendant nodes changes behavior after we set it.
		*/
		override fun onPostScroll(
		consumed: Offset,
		available: Offset,
		source: NestedScrollSource,
		): Offset {
		// If we have some remaining scroll, that scroll can be used to initiate a
		// transition between scenes. We can assume that the behavior is only needed if
		// there is some remaining amount.
		if (available != Offset.Zero) {
		requireScrollBehaviorOwner()
		.updateScrollBehaviors(
		topOrLeftBehavior = topOrLeftBehavior,
		bottomOrRightBehavior = bottomOrRightBehavior,
		isExternalOverscrollGesture = isExternalOverscrollGesture,
		)
		}

		return Offset.Zero
		}
		}

		private var priorityNestedScrollConnection: PriorityNestedScrollConnection =
		scenePriorityNestedScrollConnection(
		layoutImpl = layoutImpl,
		@@ -145,14 +190,22 @@ private class NestedScrollToSceneNode(
		dispatcher = null,
		)

		private var updateScrollBehaviorsNestedScrollNode: DelegatableNode =
		nestedScrollModifierNode(
		connection = updateScrollBehaviorsConnection,
		dispatcher = null,
		)

		override fun onAttach() {
		pointersInfoOwner = requireAncestorPointersInfoOwner()
		delegate(nestedScrollNode)
		delegate(updateScrollBehaviorsNestedScrollNode)
		}

		override fun onDetach() {
		// Make sure we reset the scroll connection when this modifier is removed from composition
		priorityNestedScrollConnection.reset()
		scrollBehaviorOwner = null
		}

		fun update(
		@@ -162,6 +215,12 @@ private class NestedScrollToSceneNode(
		bottomOrRightBehavior: NestedScrollBehavior,
		isExternalOverscrollGesture: () -> Boolean,
		) {
		this.layoutImpl = layoutImpl
		this.orientation = orientation
		this.topOrLeftBehavior = topOrLeftBehavior
		this.bottomOrRightBehavior = bottomOrRightBehavior
		this.isExternalOverscrollGesture = isExternalOverscrollGesture

		// Clean up the old nested scroll connection
		priorityNestedScrollConnection.reset()
		undelegate(nestedScrollNode)

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

+48 −5

Original line number	Diff line number	Diff line
		@@ -22,9 +22,12 @@ import androidx.compose.ui.Modifier
		import androidx.compose.ui.geometry.Offset
		import androidx.compose.ui.input.pointer.PointerEvent
		import androidx.compose.ui.input.pointer.PointerEventPass
		import androidx.compose.ui.node.DelegatableNode
		import androidx.compose.ui.node.DelegatingNode
		import androidx.compose.ui.node.ModifierNodeElement
		import androidx.compose.ui.node.PointerInputModifierNode
		import androidx.compose.ui.node.TraversableNode
		import androidx.compose.ui.node.findNearestAncestor
		import androidx.compose.ui.unit.IntSize

		/**
		@@ -53,7 +56,7 @@ private class SwipeToSceneNode(
		draggableHandler: DraggableHandlerImpl,
		swipeDetector: SwipeDetector,
		) : DelegatingNode(), PointerInputModifierNode {
		private val delegate =
		private val multiPointerDraggableNode =
		delegate(
		MultiPointerDraggableNode(
		orientation = draggableHandler.orientation,
		@@ -74,21 +77,25 @@ private class SwipeToSceneNode(
		// Make sure to update the delegate orientation. Note that this will automatically
		// reset the underlying pointer input handler, so previous gestures will be
		// cancelled.
		delegate.orientation = value.orientation
		multiPointerDraggableNode.orientation = value.orientation
		}
		}

		override fun onAttach() {
		delegate(ScrollBehaviorOwnerNode(draggableHandler.nestedScrollKey))
		}

		override fun onPointerEvent(
		pointerEvent: PointerEvent,
		pass: PointerEventPass,
		bounds: IntSize,
		) = delegate.onPointerEvent(pointerEvent, pass, bounds)
		) = multiPointerDraggableNode.onPointerEvent(pointerEvent, pass, bounds)

		override fun onCancelPointerInput() = delegate.onCancelPointerInput()
		override fun onCancelPointerInput() = multiPointerDraggableNode.onCancelPointerInput()

		private fun enabled(): Boolean {
		return draggableHandler.isDrivingTransition \|\|
		currentScene().shouldEnableSwipes(delegate.orientation)
		currentScene().shouldEnableSwipes(multiPointerDraggableNode.orientation)
		}

		private fun currentScene(): Scene {
		@@ -118,3 +125,39 @@ private class SwipeToSceneNode(
		return currentScene().shouldEnableSwipes(oppositeOrientation)
		}
		}

		/** Find the [ScrollBehaviorOwner] for the current orientation. */
		internal fun DelegatableNode.requireScrollBehaviorOwner(
		draggableHandler: DraggableHandlerImpl
		): ScrollBehaviorOwner {
		val ancestorNode =
		checkNotNull(findNearestAncestor(draggableHandler.nestedScrollKey)) {
		"This should never happen! Couldn't find a ScrollBehaviorOwner. " +
		"Are we inside an SceneTransitionLayout?"
		}
		return ancestorNode as ScrollBehaviorOwner
		}

		internal fun interface ScrollBehaviorOwner {
		fun updateScrollBehaviors(
		topOrLeftBehavior: NestedScrollBehavior,
		bottomOrRightBehavior: NestedScrollBehavior,
		isExternalOverscrollGesture: () -> Boolean,
		)
		}

		/**
		* We need a node that receives the desired behavior.
		*
		* TODO(b/353234530) move this logic into [SwipeToSceneNode]
		*/
		private class ScrollBehaviorOwnerNode(override val traverseKey: Any) :
		Modifier.Node(), TraversableNode, ScrollBehaviorOwner {
		override fun updateScrollBehaviors(
		topOrLeftBehavior: NestedScrollBehavior,
		bottomOrRightBehavior: NestedScrollBehavior,
		isExternalOverscrollGesture: () -> Boolean
		) {
		// This method will be used to update the desired behavior in a following CL.
		}
		}