Only compute drag distance when necessary (c1553651) · Commits · e / os / android_frameworks_base

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

+41 −47

Original line number	Original line	Diff line number	Diff line
	@@ -146,9 +146,10 @@ internal class SceneGestureHandler(
	val fromScene = layoutImpl.scene(transitionState.currentScene)		val fromScene = layoutImpl.scene(transitionState.currentScene)
	updateSwipes(fromScene, startedPosition, pointersDown)		updateSwipes(fromScene, startedPosition, pointersDown)

	val (targetScene, distance) =		val result =
	findTargetSceneAndDistance(fromScene, overSlop, updateSwipesResults = true) ?: return		findUserActionResult(fromScene, directionOffset = overSlop, updateSwipesResults = true)
	updateTransition(SwipeTransition(fromScene, targetScene, distance), force = true)		?: return
			updateTransition(SwipeTransition(fromScene, result), force = true)
	}		}

	private fun updateSwipes(fromScene: Scene, startedPosition: Offset?, pointersDown: Int) {		private fun updateSwipes(fromScene: Scene, startedPosition: Offset?, pointersDown: Int) {
	@@ -224,8 +225,8 @@ internal class SceneGestureHandler(
	computeFromSceneConsideringAcceleratedSwipe(swipeTransition)		computeFromSceneConsideringAcceleratedSwipe(swipeTransition)

	val isNewFromScene = fromScene.key != swipeTransition.fromScene		val isNewFromScene = fromScene.key != swipeTransition.fromScene
	val (targetScene, distance) =		val result =
	findTargetSceneAndDistance(		findUserActionResult(
	fromScene,		fromScene,
	swipeTransition.dragOffset,		swipeTransition.dragOffset,
	updateSwipesResults = isNewFromScene,		updateSwipesResults = isNewFromScene,
	@@ -236,9 +237,9 @@ internal class SceneGestureHandler(
	}		}
	swipeTransition.dragOffset += acceleratedOffset		swipeTransition.dragOffset += acceleratedOffset

	if (isNewFromScene \|\| targetScene.key != swipeTransition.toScene) {		if (isNewFromScene \|\| result.toScene != swipeTransition.toScene) {
	updateTransition(		updateTransition(
	SwipeTransition(fromScene, targetScene, distance).apply {		SwipeTransition(fromScene, result).apply {
	this.dragOffset = swipeTransition.dragOffset		this.dragOffset = swipeTransition.dragOffset
	}		}
	)		)
	@@ -306,7 +307,7 @@ internal class SceneGestureHandler(
	}		}

	/**		/**
	* Returns the target scene and distance from [fromScene] in the direction [directionOffset].		* Returns the [UserActionResult] from [fromScene] in the direction of [directionOffset].
	*		*
	* @param fromScene the scene from which we look for the target		* @param fromScene the scene from which we look for the target
	* @param directionOffset signed float that indicates the direction. Positive is down or right		* @param directionOffset signed float that indicates the direction. Positive is down or right
	@@ -322,57 +323,42 @@ internal class SceneGestureHandler(
	* [directionOffset] is 0f and both direction are available, it will default to		* [directionOffset] is 0f and both direction are available, it will default to
	* [upOrLeftResult].		* [upOrLeftResult].
	*/		*/
	private inline fun findTargetSceneAndDistance(		private fun findUserActionResult(
	fromScene: Scene,		fromScene: Scene,
	directionOffset: Float,		directionOffset: Float,
	updateSwipesResults: Boolean,		updateSwipesResults: Boolean,
	): Pair<Scene, Float>? {		): UserActionResult? {
	if (updateSwipesResults) updateSwipesResults(fromScene)		if (updateSwipesResults) updateSwipesResults(fromScene)

	// Compute the target scene depending on the current offset.
	return when {		return when {
	upOrLeftResult == null && downOrRightResult == null -> null		upOrLeftResult == null && downOrRightResult == null -> null
	(directionOffset < 0f && upOrLeftResult != null) \|\| downOrRightResult == null ->		(directionOffset < 0f && upOrLeftResult != null) \|\| downOrRightResult == null ->
	upOrLeftResult?.let { result ->		upOrLeftResult
	Pair(		else -> downOrRightResult
	layoutImpl.scene(result.toScene),
	-fromScene.getAbsoluteDistance(result.distance)
	)
	}
	else ->
	downOrRightResult?.let { result ->
	Pair(
	layoutImpl.scene(result.toScene),
	fromScene.getAbsoluteDistance(result.distance)
	)
	}
	}		}
	}		}

	/**		/**
	* A strict version of [findTargetSceneAndDistance] that will return null when there is no Scene		* A strict version of [findUserActionResult] that will return null when there is no Scene in
	* in [directionOffset] direction		* [directionOffset] direction
	*/		*/
	private inline fun findTargetSceneAndDistanceStrict(		private fun findUserActionResultStrict(directionOffset: Float): UserActionResult? {
	fromScene: Scene,
	directionOffset: Float,
	): Pair<Scene, Float>? {
	return when {		return when {
	directionOffset > 0f ->		directionOffset > 0f -> upOrLeftResult
	upOrLeftResult?.let { result ->		directionOffset < 0f -> downOrRightResult
	Pair(		else -> null
	layoutImpl.scene(result.toScene),
	-fromScene.getAbsoluteDistance(result.distance),
	)
	}		}
	directionOffset < 0f ->
	downOrRightResult?.let { result ->
	Pair(
	layoutImpl.scene(result.toScene),
	fromScene.getAbsoluteDistance(result.distance),
	)
	}		}
	else -> null
			private fun computeAbsoluteDistance(
			fromScene: Scene,
			result: UserActionResult,
			): Float {
			return if (result == upOrLeftResult) {
			-fromScene.getAbsoluteDistance(result.distance)
			} else {
			check(result == downOrRightResult)
			fromScene.getAbsoluteDistance(result.distance)
	}		}
	}		}

	@@ -440,8 +426,8 @@ internal class SceneGestureHandler(

	if (startFromIdlePosition) {		if (startFromIdlePosition) {
	// If there is a target scene, we start the overscroll animation.		// If there is a target scene, we start the overscroll animation.
	val (targetScene, distance) =		val result =
	findTargetSceneAndDistanceStrict(fromScene, velocity)		findUserActionResultStrict(velocity)
	?: run {		?: run {
	// We will not animate		// We will not animate
	layoutState.finishTransition(swipeTransition, idleScene = fromScene.key)		layoutState.finishTransition(swipeTransition, idleScene = fromScene.key)
	@@ -449,7 +435,7 @@ internal class SceneGestureHandler(
	}		}

	updateTransition(		updateTransition(
	SwipeTransition(fromScene, targetScene, distance).apply {		SwipeTransition(fromScene, result).apply {
	_currentScene = swipeTransition._currentScene		_currentScene = swipeTransition._currentScene
	}		}
	)		)
	@@ -496,6 +482,14 @@ internal class SceneGestureHandler(
	}		}
	}		}

			private fun SwipeTransition(fromScene: Scene, result: UserActionResult): SwipeTransition {
			return SwipeTransition(
			fromScene,
			layoutImpl.scene(result.toScene),
			computeAbsoluteDistance(fromScene, result),
			)
			}

	internal class SwipeTransition(		internal class SwipeTransition(
	val _fromScene: Scene,		val _fromScene: Scene,
	val _toScene: Scene,		val _toScene: Scene,