Extract compute(Swipes,SwipesResults) in SceneGestureHandler (e66735e3) · Commits · e / os / android_frameworks_base

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

+63 −31

Original line number	Diff line number	Diff line
		@@ -77,11 +77,8 @@ internal class SceneGestureHandler(

		internal var currentSource: Any? = null

		/** The [Swipe]s associated to the current gesture. */
		private var upOrLeftSwipe: Swipe? = null
		private var downOrRightSwipe: Swipe? = null
		private var upOrLeftNoSourceSwipe: Swipe? = null
		private var downOrRightNoSourceSwipe: Swipe? = null
		/** The [Swipes] associated to the current gesture. */
		private var swipes: Swipes? = null

		/** The [UserActionResult] associated to up and down swipes. */
		private var upOrLeftResult: UserActionResult? = null
		@@ -92,7 +89,7 @@ internal class SceneGestureHandler(
		// This [transition] was already driving the animation: simply take over it.
		// Stop animating and start from where the current offset.
		swipeTransition.cancelOffsetAnimation()
		updateTargetResults(swipeTransition._fromScene)
		updateSwipesResults(swipeTransition._fromScene)
		return
		}

		@@ -111,15 +108,22 @@ internal class SceneGestureHandler(
		}

		val fromScene = layoutImpl.scene(transitionState.currentScene)
		setCurrentActions(fromScene, startedPosition, pointersDown)
		updateSwipes(fromScene, startedPosition, pointersDown)

		val (targetScene, distance) =
		findTargetSceneAndDistance(fromScene, overSlop, updateScenes = true) ?: return

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

		private fun setCurrentActions(fromScene: Scene, startedPosition: Offset?, pointersDown: Int) {
		private fun updateSwipes(fromScene: Scene, startedPosition: Offset?, pointersDown: Int) {
		this.swipes = computeSwipes(fromScene, startedPosition, pointersDown)
		}

		private fun computeSwipes(
		fromScene: Scene,
		startedPosition: Offset?,
		pointersDown: Int
		): Swipes {
		val fromSource =
		startedPosition?.let { position ->
		layoutImpl.swipeSourceDetector.source(
		@@ -152,16 +156,20 @@ internal class SceneGestureHandler(
		fromSource = fromSource,
		)

		if (fromSource == null) {
		upOrLeftSwipe = null
		downOrRightSwipe = null
		upOrLeftNoSourceSwipe = upOrLeft
		downOrRightNoSourceSwipe = downOrRight
		return if (fromSource == null) {
		Swipes(
		upOrLeft = null,
		downOrRight = null,
		upOrLeftNoSource = upOrLeft,
		downOrRightNoSource = downOrRight,
		)
		} else {
		upOrLeftSwipe = upOrLeft
		downOrRightSwipe = downOrRight
		upOrLeftNoSourceSwipe = upOrLeft.copy(fromSource = null)
		downOrRightNoSourceSwipe = downOrRight.copy(fromSource = null)
		Swipes(
		upOrLeft = upOrLeft,
		downOrRight = downOrRight,
		upOrLeftNoSource = upOrLeft.copy(fromSource = null),
		downOrRightNoSource = downOrRight.copy(fromSource = null),
		)
		}
		}

		@@ -184,7 +192,7 @@ internal class SceneGestureHandler(
		findTargetSceneAndDistance(
		fromScene,
		swipeTransition.dragOffset,
		updateScenes = isNewFromScene,
		updateSwipesResults = isNewFromScene,
		)
		?: run {
		onDragStopped(delta, true)
		@@ -201,15 +209,31 @@ internal class SceneGestureHandler(
		}
		}

		private fun updateTargetResults(fromScene: Scene) {
		private fun updateSwipesResults(fromScene: Scene) {
		val (upOrLeftResult, downOrRightResult) =
		swipesResults(
		fromScene,
		this.swipes ?: error("updateSwipes() should be called before updateSwipesResults()")
		)

		this.upOrLeftResult = upOrLeftResult
		this.downOrRightResult = downOrRightResult
		}

		private fun swipesResults(
		fromScene: Scene,
		swipes: Swipes
		): Pair<UserActionResult?, UserActionResult?> {
		val userActions = fromScene.userActions
		fun sceneToSwipePair(swipe: Swipe?): UserActionResult? {
		return userActions[swipe ?: return null]
		}

		upOrLeftResult = sceneToSwipePair(upOrLeftSwipe) ?: sceneToSwipePair(upOrLeftNoSourceSwipe)
		downOrRightResult =
		sceneToSwipePair(downOrRightSwipe) ?: sceneToSwipePair(downOrRightNoSourceSwipe)
		val upOrLeftResult =
		sceneToSwipePair(swipes.upOrLeft) ?: sceneToSwipePair(swipes.upOrLeftNoSource)
		val downOrRightResult =
		sceneToSwipePair(swipes.downOrRight) ?: sceneToSwipePair(swipes.downOrRightNoSource)
		return Pair(upOrLeftResult, downOrRightResult)
		}

		/**
		@@ -251,11 +275,11 @@ internal class SceneGestureHandler(
		* @param fromScene the scene from which we look for the target
		* @param directionOffset signed float that indicates the direction. Positive is down or right
		* negative is up or left.
		* @param updateScenes whether the target scenes should be updated to the current values held in
		* the Scenes map. Usually we don't want to update them while doing a drag, because this could
		* change the target scene (jump cutting) to a different scene, when some system state changed
		* the targets the background. However, an update is needed any time we calculate the targets
		* for a new fromScene.
		* @param updateSwipesResults whether the target scenes should be updated to the current values
		* held in the Scenes map. Usually we don't want to update them while doing a drag, because
		* this could change the target scene (jump cutting) to a different scene, when some system
		* state changed the targets the background. However, an update is needed any time we
		* calculate the targets for a new fromScene.
		* @return null when there are no targets in either direction. If one direction is null and you
		* drag into the null direction this function will return the opposite direction, assuming
		* that the users intention is to start the drag into the other direction eventually. If
		@@ -265,9 +289,9 @@ internal class SceneGestureHandler(
		private inline fun findTargetSceneAndDistance(
		fromScene: Scene,
		directionOffset: Float,
		updateScenes: Boolean,
		updateSwipesResults: Boolean,
		): Pair<Scene, Float>? {
		if (updateScenes) updateTargetResults(fromScene)
		if (updateSwipesResults) updateSwipesResults(fromScene)

		// Compute the target scene depending on the current offset.
		return when {
		@@ -545,6 +569,14 @@ internal class SceneGestureHandler(
		}.toFloat()
		}
		}

		/** The [Swipe] associated to a given fromScene, startedPosition and pointersDown. */
		private class Swipes(
		val upOrLeft: Swipe?,
		val downOrRight: Swipe?,
		val upOrLeftNoSource: Swipe?,
		val downOrRightNoSource: Swipe?,
		)
		}

		private class SceneDraggableHandler(