Merge "STL: Reset PriorityNestedScrollConnection on first pointer down" into main (9e701690) · Commits · e / os / android_frameworks_base

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

+7 −0

Original line number	Diff line number	Diff line
		@@ -81,6 +81,7 @@ internal fun Modifier.multiPointerDraggable(
		enabled: () -> Boolean,
		startDragImmediately: (startedPosition: Offset) -> Boolean,
		onDragStarted: (startedPosition: Offset, overSlop: Float, pointersDown: Int) -> DragController,
		onFirstPointerDown: () -> Unit = {},
		swipeDetector: SwipeDetector = DefaultSwipeDetector,
		dispatcher: NestedScrollDispatcher,
		): Modifier =
		@@ -90,6 +91,7 @@ internal fun Modifier.multiPointerDraggable(
		enabled,
		startDragImmediately,
		onDragStarted,
		onFirstPointerDown,
		swipeDetector,
		dispatcher,
		)
		@@ -101,6 +103,7 @@ private data class MultiPointerDraggableElement(
		private val startDragImmediately: (startedPosition: Offset) -> Boolean,
		private val onDragStarted:
		(startedPosition: Offset, overSlop: Float, pointersDown: Int) -> DragController,
		private val onFirstPointerDown: () -> Unit,
		private val swipeDetector: SwipeDetector,
		private val dispatcher: NestedScrollDispatcher,
		) : ModifierNodeElement<MultiPointerDraggableNode>() {
		@@ -110,6 +113,7 @@ private data class MultiPointerDraggableElement(
		enabled = enabled,
		startDragImmediately = startDragImmediately,
		onDragStarted = onDragStarted,
		onFirstPointerDown = onFirstPointerDown,
		swipeDetector = swipeDetector,
		dispatcher = dispatcher,
		)
		@@ -119,6 +123,7 @@ private data class MultiPointerDraggableElement(
		node.enabled = enabled
		node.startDragImmediately = startDragImmediately
		node.onDragStarted = onDragStarted
		node.onFirstPointerDown = onFirstPointerDown
		node.swipeDetector = swipeDetector
		}
		}
		@@ -129,6 +134,7 @@ internal class MultiPointerDraggableNode(
		var startDragImmediately: (startedPosition: Offset) -> Boolean,
		var onDragStarted:
		(startedPosition: Offset, overSlop: Float, pointersDown: Int) -> DragController,
		var onFirstPointerDown: () -> Unit,
		var swipeDetector: SwipeDetector = DefaultSwipeDetector,
		private val dispatcher: NestedScrollDispatcher,
		) :
		@@ -225,6 +231,7 @@ internal class MultiPointerDraggableNode(
		startedPosition = null
		} else if (startedPosition == null) {
		startedPosition = pointers.first().position
		onFirstPointerDown()
		}
		}
		}

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

+10 −0

Original line number	Diff line number	Diff line
		@@ -67,6 +67,7 @@ private class SwipeToSceneNode(
		enabled = ::enabled,
		startDragImmediately = ::startDragImmediately,
		onDragStarted = draggableHandler::onDragStarted,
		onFirstPointerDown = ::onFirstPointerDown,
		swipeDetector = swipeDetector,
		dispatcher = dispatcher,
		)
		@@ -101,6 +102,15 @@ private class SwipeToSceneNode(
		delegate(ScrollBehaviorOwnerNode(draggableHandler.nestedScrollKey, nestedScrollHandlerImpl))
		}

		private fun onFirstPointerDown() {
		// When we drag our finger across the screen, the NestedScrollConnection keeps track of all
		// the scroll events until we lift our finger. However, in some cases, the connection might
		// not receive the "up" event. This can lead to an incorrect initial state for the gesture.
		// To prevent this issue, we can call the reset() method when the first finger touches the
		// screen. This ensures that the NestedScrollConnection starts from a correct state.
		nestedScrollHandlerImpl.connection.reset()
		}

		override fun onDetach() {
		// Make sure we reset the scroll connection when this modifier is removed from composition
		nestedScrollHandlerImpl.connection.reset()

packages/SystemUI/compose/scene/src/com/android/compose/nestedscroll/PriorityNestedScrollConnection.kt

+5 −1

Original line number	Diff line number	Diff line
		@@ -129,7 +129,11 @@ class PriorityNestedScrollConnection(
		return onPriorityStop(available)
		}

		/** Method to call before destroying the object or to reset the initial state. */
		/**
		* Method to call before destroying the object or to reset the initial state.
		*
		* TODO(b/303224944) This method should be removed.
		*/
		fun reset() {
		// Step 3c: To ensure that an onStop is always called for every onStart.
		onPriorityStop(velocity = Velocity.Zero)

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

+37 −0

Original line number	Diff line number	Diff line
		@@ -23,6 +23,9 @@ import androidx.compose.foundation.layout.Spacer
		import androidx.compose.foundation.layout.fillMaxSize
		import androidx.compose.foundation.layout.size
		import androidx.compose.runtime.Composable
		import androidx.compose.runtime.getValue
		import androidx.compose.runtime.mutableStateOf
		import androidx.compose.runtime.setValue
		import androidx.compose.ui.Modifier
		import androidx.compose.ui.geometry.Offset
		import androidx.compose.ui.platform.LocalViewConfiguration
		@@ -266,4 +269,38 @@ class NestedScrollToSceneTest {
		val transition = assertThat(state.transitionState).isTransition()
		assertThat(transition).hasProgress(0.5f)
		}

		@Test
		fun resetScrollTracking_afterMissingPointerUpEvent() {
		var canScroll = true
		var hasScrollable by mutableStateOf(true)
		val state = setup2ScenesAndScrollTouchSlop {
		if (hasScrollable) {
		Modifier.scrollable(rememberScrollableState { if (canScroll) it else 0f }, Vertical)
		} else {
		Modifier
		}
		}

		// The gesture is consumed by the component in the scene.
		scrollUp(percent = 0.2f)

		// STL keeps track of the scroll consumed. The scene remains in Idle.
		assertThat(state.transitionState).isIdle()

		// The scrollable component disappears, and does not send the signal (pointer up) to reset
		// the consumed amount.
		hasScrollable = false
		pointerUp()

		// A new scrollable component appears and allows the scene to consume the scroll.
		hasScrollable = true
		canScroll = false
		pointerDownAndScrollTouchSlop()
		scrollUp(percent = 0.2f)

		// STL can only start the transition if it has reset the amount of scroll consumed.
		val transition = assertThat(state.transitionState).isTransition()
		assertThat(transition).hasProgress(0.2f)
		}
		}