Merge "Simplify the swipe offset animation logic" into main (76537378) · Commits · e / os / android_frameworks_base

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

+31 −42

Original line number	Diff line number	Diff line
		@@ -20,6 +20,7 @@ package com.android.compose.animation.scene

		import android.util.Log
		import androidx.compose.animation.core.Animatable
		import androidx.compose.animation.core.AnimationVector1D
		import androidx.compose.animation.core.SpringSpec
		import androidx.compose.foundation.gestures.Orientation
		import androidx.compose.runtime.getValue
		@@ -573,7 +574,7 @@ private class SwipeTransition(
		// 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 offset = offsetAnimation?.animatable?.value ?: dragOffset

		val distance = distance()
		if (distance == DistanceUnspecified) {
		@@ -588,20 +589,11 @@ private class SwipeTransition(
		/** The current offset caused by the drag gesture. */
		var dragOffset by mutableFloatStateOf(0f)

		/**
		* Whether the offset is animated (the user lifted their finger) or if it is driven by gesture.
		*/
		var isAnimatingOffset by mutableStateOf(false)
		/** The offset animation that animates the offset once the user lifts their finger. */
		private var offsetAnimation: OffsetAnimation? by mutableStateOf(null)

		// If we are not animating offset, it means the offset is being driven by the user's finger.
		override val isUserInputOngoing: Boolean
		get() = !isAnimatingOffset

		/** The animatable used to animate the offset once the user lifted its finger. */
		val offsetAnimatable = Animatable(0f, OffsetVisibilityThreshold)

		/** Job to check that there is at most one offset animation in progress. */
		private var offsetAnimationJob: Job? = null
		get() = offsetAnimation == null

		/**
		* The [TransformationSpecImpl] associated to this transition.
		@@ -647,25 +639,21 @@ private class SwipeTransition(
		return distance
		}

		/** Ends any previous [offsetAnimationJob] and runs the new [job]. */
		private fun startOffsetAnimation(job: () -> Job) {
		/** Ends any previous [offsetAnimation] and runs the new [animation]. */
		private fun startOffsetAnimation(animation: () -> OffsetAnimation) {
		cancelOffsetAnimation()
		offsetAnimationJob = job()
		offsetAnimation = animation()
		}

		/** Cancel any ongoing offset animation. */
		// TODO(b/317063114) This should be a suspended function to avoid multiple jobs running at
		// the same time.
		fun cancelOffsetAnimation() {
		offsetAnimationJob?.cancel()
		finishOffsetAnimation()
		}
		val animation = offsetAnimation ?: return
		offsetAnimation = null

		fun finishOffsetAnimation() {
		if (isAnimatingOffset) {
		isAnimatingOffset = false
		dragOffset = offsetAnimatable.value
		}
		dragOffset = animation.animatable.value
		animation.job.cancel()
		}

		fun animateOffset(
		@@ -676,29 +664,30 @@ private class SwipeTransition(
		onAnimationCompleted: () -> Unit,
		) {
		startOffsetAnimation {
		val animatable = Animatable(dragOffset, OffsetVisibilityThreshold)
		val job =
		coroutineScope.launch {
		animateOffset(targetOffset, initialVelocity)
		animatable.animateTo(
		targetValue = targetOffset,
		animationSpec = swipeSpec,
		initialVelocity = initialVelocity,
		)

		onAnimationCompleted()
		}

		OffsetAnimation(animatable, job)
		}
		}

		private suspend fun animateOffset(targetOffset: Float, initialVelocity: Float) {
		if (!isAnimatingOffset) {
		offsetAnimatable.snapTo(dragOffset)
		}
		isAnimatingOffset = true
		private class OffsetAnimation(
		/** The animatable used to animate the offset. */
		val animatable: Animatable<Float, AnimationVector1D>,

		val animationSpec = transformationSpec
		offsetAnimatable.animateTo(
		targetValue = targetOffset,
		animationSpec = swipeSpec,
		initialVelocity = initialVelocity,
		/** The job in which [animatable] is animated. */
		val job: Job,
		)

		finishOffsetAnimation()
		}

		companion object {
		const val DistanceUnspecified = 0f
		}

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

+11 −0

Original line number	Diff line number	Diff line
		@@ -951,4 +951,15 @@ class DraggableHandlerTest {
		assertThat(transition).isNotNull()
		assertThat(transition!!.progress).isEqualTo(-0.1f)
		}

		@Test
		fun transitionIsImmediatelyUpdatedWhenReleasingFinger() = runGestureTest {
		// Swipe up from the middle to transition to scene B.
		val middle = Offset(SCREEN_SIZE / 2f, SCREEN_SIZE / 2f)
		val dragController = onDragStarted(startedPosition = middle, overSlop = up(0.1f))
		assertTransition(fromScene = SceneA, toScene = SceneB, isUserInputOngoing = true)

		dragController.onDragStopped(velocity = 0f)
		assertTransition(isUserInputOngoing = false)
		}
		}