Add support for swipe with multiple fingers (de94ac9d) · Commits · e / os / android_frameworks_base

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

+2 −3

Original line number	Original line	Diff line number	Diff line
	@@ -2,7 +2,6 @@ package com.android.compose.animation.scene

	import androidx.compose.ui.geometry.Offset		import androidx.compose.ui.geometry.Offset
	import androidx.compose.ui.input.nestedscroll.NestedScrollConnection		import androidx.compose.ui.input.nestedscroll.NestedScrollConnection
	import kotlinx.coroutines.CoroutineScope

	interface GestureHandler {		interface GestureHandler {
	val draggable: DraggableHandler		val draggable: DraggableHandler
	@@ -10,9 +9,9 @@ interface GestureHandler {
	}		}

	interface DraggableHandler {		interface DraggableHandler {
	suspend fun onDragStarted(coroutineScope: CoroutineScope, startedPosition: Offset)		fun onDragStarted(startedPosition: Offset, pointersDown: Int = 1)
	fun onDelta(pixels: Float)		fun onDelta(pixels: Float)
	suspend fun onDragStopped(coroutineScope: CoroutineScope, velocity: Float)		fun onDragStopped(velocity: Float)
	}		}

	interface NestedScrollHandler {		interface NestedScrollHandler {

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

0 → 100644

+191 −0

Original line number	Original line	Diff line number	Diff line
			/*
			* Copyright (C) 2023 The Android Open Source Project
			*
			* Licensed under the Apache License, Version 2.0 (the "License");
			* you may not use this file except in compliance with the License.
			* You may obtain a copy of the License at
			*
			* http://www.apache.org/licenses/LICENSE-2.0
			*
			* Unless required by applicable law or agreed to in writing, software
			* distributed under the License is distributed on an "AS IS" BASIS,
			* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
			* See the License for the specific language governing permissions and
			* limitations under the License.
			*/

			package com.android.compose.animation.scene

			import androidx.compose.foundation.gestures.Orientation
			import androidx.compose.foundation.gestures.awaitEachGesture
			import androidx.compose.foundation.gestures.awaitFirstDown
			import androidx.compose.foundation.gestures.awaitHorizontalTouchSlopOrCancellation
			import androidx.compose.foundation.gestures.awaitVerticalTouchSlopOrCancellation
			import androidx.compose.foundation.gestures.horizontalDrag
			import androidx.compose.foundation.gestures.verticalDrag
			import androidx.compose.runtime.Composable
			import androidx.compose.runtime.getValue
			import androidx.compose.runtime.remember
			import androidx.compose.runtime.rememberUpdatedState
			import androidx.compose.ui.Modifier
			import androidx.compose.ui.geometry.Offset
			import androidx.compose.ui.input.pointer.PointerEventPass
			import androidx.compose.ui.input.pointer.PointerId
			import androidx.compose.ui.input.pointer.PointerInputChange
			import androidx.compose.ui.input.pointer.PointerInputScope
			import androidx.compose.ui.input.pointer.pointerInput
			import androidx.compose.ui.input.pointer.positionChange
			import androidx.compose.ui.input.pointer.util.VelocityTracker
			import androidx.compose.ui.input.pointer.util.addPointerInputChange
			import androidx.compose.ui.platform.LocalViewConfiguration
			import androidx.compose.ui.unit.Velocity
			import androidx.compose.ui.util.fastForEach

			/**
			* Make an element draggable in the given [orientation].
			*
			* The main difference with [multiPointerDraggable] and
			* [androidx.compose.foundation.gestures.draggable] is that [onDragStarted] also receives the number
			* of pointers that are down when the drag is started. If you don't need this information, you
			* should use `draggable` instead.
			*
			* Note that the current implementation is trivial: we wait for the touch slope on the first down
			* pointer, then we count the number of distinct pointers that are down right before calling
			* [onDragStarted]. This means that the drag won't start when a first pointer is down (but not
			* dragged) and a second pointer is down and dragged. This is an implementation detail that might
			* change in the future.
			*/
			// TODO(b/291055080): Migrate to the Modifier.Node API.
			@Composable
			internal fun Modifier.multiPointerDraggable(
			orientation: Orientation,
			enabled: Boolean,
			startDragImmediately: Boolean,
			onDragStarted: (startedPosition: Offset, pointersDown: Int) -> Unit,
			onDragDelta: (Float) -> Unit,
			onDragStopped: (velocity: Float) -> Unit,
			): Modifier {
			val onDragStarted by rememberUpdatedState(onDragStarted)
			val onDragStopped by rememberUpdatedState(onDragStopped)
			val onDragDelta by rememberUpdatedState(onDragDelta)
			val startDragImmediately by rememberUpdatedState(startDragImmediately)

			val velocityTracker = remember { VelocityTracker() }
			val maxFlingVelocity =
			LocalViewConfiguration.current.maximumFlingVelocity.let { max ->
			val maxF = max.toFloat()
			Velocity(maxF, maxF)
			}

			return this.pointerInput(enabled, orientation, maxFlingVelocity) {
			if (!enabled) {
			return@pointerInput
			}

			val onDragStart: (Offset, Int) -> Unit = { startedPosition, pointersDown ->
			velocityTracker.resetTracking()
			onDragStarted(startedPosition, pointersDown)
			}

			val onDragCancel: () -> Unit = { onDragStopped(/* velocity= */ 0f) }

			val onDragEnd: () -> Unit = {
			val velocity = velocityTracker.calculateVelocity(maxFlingVelocity)
			onDragStopped(
			when (orientation) {
			Orientation.Horizontal -> velocity.x
			Orientation.Vertical -> velocity.y
			}
			)
			}

			val onDrag: (change: PointerInputChange, dragAmount: Float) -> Unit = { change, amount ->
			velocityTracker.addPointerInputChange(change)
			onDragDelta(amount)
			}

			detectDragGestures(
			orientation = orientation,
			startDragImmediately = { startDragImmediately },
			onDragStart = onDragStart,
			onDragEnd = onDragEnd,
			onDragCancel = onDragCancel,
			onDrag = onDrag,
			)
			}
			}

			/**
			* Detect drag gestures in the given [orientation].
			*
			* This function is a mix of [androidx.compose.foundation.gestures.awaitDownAndSlop] and
			* [androidx.compose.foundation.gestures.detectVerticalDragGestures] to add support for:
			* 1) starting the gesture immediately without requiring a drag >= touch slope;
			* 2) passing the number of pointers down to [onDragStart].
			*/
			private suspend fun PointerInputScope.detectDragGestures(
			orientation: Orientation,
			startDragImmediately: () -> Boolean,
			onDragStart: (startedPosition: Offset, pointersDown: Int) -> Unit,
			onDragEnd: () -> Unit,
			onDragCancel: () -> Unit,
			onDrag: (change: PointerInputChange, dragAmount: Float) -> Unit,
			) {
			awaitEachGesture {
			val initialDown = awaitFirstDown(requireUnconsumed = false, pass = PointerEventPass.Initial)
			var overSlop = 0f
			val drag =
			if (startDragImmediately()) {
			initialDown.consume()
			initialDown
			} else {
			val down = awaitFirstDown(requireUnconsumed = false)
			val onSlopReached = { change: PointerInputChange, over: Float ->
			change.consume()
			overSlop = over
			}

			// TODO(b/291055080): Replace by await[Orientation]PointerSlopOrCancellation once
			// it is public.
			when (orientation) {
			Orientation.Horizontal ->
			awaitHorizontalTouchSlopOrCancellation(down.id, onSlopReached)
			Orientation.Vertical ->
			awaitVerticalTouchSlopOrCancellation(down.id, onSlopReached)
			}
			}

			if (drag != null) {
			// Count the number of pressed pointers.
			val pressed = mutableSetOf<PointerId>()
			currentEvent.changes.fastForEach { change ->
			if (change.pressed) {
			pressed.add(change.id)
			}
			}

			onDragStart(drag.position, pressed.size)
			onDrag(drag, overSlop)

			val successful =
			when (orientation) {
			Orientation.Horizontal ->
			horizontalDrag(drag.id) {
			onDrag(it, it.positionChange().x)
			it.consume()
			}
			Orientation.Vertical ->
			verticalDrag(drag.id) {
			onDrag(it, it.positionChange().y)
			it.consume()
			}
			}

			if (successful) {
			onDragEnd()
			} else {
			onDragCancel()
			}
			}
			}
			}

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

+0 −17

Original line number	Original line	Diff line number	Diff line
	@@ -16,7 +16,6 @@

	package com.android.compose.animation.scene		package com.android.compose.animation.scene

	import androidx.compose.foundation.gestures.Orientation
	import androidx.compose.foundation.layout.Box		import androidx.compose.foundation.layout.Box
	import androidx.compose.runtime.Composable		import androidx.compose.runtime.Composable
	import androidx.compose.runtime.State		import androidx.compose.runtime.State
	@@ -101,19 +100,3 @@ private class SceneScopeImpl(
	MovableElement(layoutImpl, scene, key, modifier, content)		MovableElement(layoutImpl, scene, key, modifier, content)
	}		}
	}		}

	/** The destination scene when swiping up or left from [upOrLeft]. */
	internal fun Scene.upOrLeft(orientation: Orientation): SceneKey? {
	return when (orientation) {
	Orientation.Vertical -> userActions[Swipe.Up]
	Orientation.Horizontal -> userActions[Swipe.Left]
	}
	}

	/** The destination scene when swiping down or right from [downOrRight]. */
	internal fun Scene.downOrRight(orientation: Orientation): SceneKey? {
	return when (orientation) {
	Orientation.Vertical -> userActions[Swipe.Down]
	Orientation.Horizontal -> userActions[Swipe.Right]
	}
	}

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

+6 −5

Original line number	Original line	Diff line number	Diff line
	@@ -16,6 +16,7 @@

	package com.android.compose.animation.scene		package com.android.compose.animation.scene

			import androidx.compose.foundation.gestures.Orientation
	import androidx.compose.runtime.Composable		import androidx.compose.runtime.Composable
	import androidx.compose.runtime.State		import androidx.compose.runtime.State
	import androidx.compose.runtime.remember		import androidx.compose.runtime.remember
	@@ -191,9 +192,9 @@ data class Swipe(
	}		}
	}		}

	enum class SwipeDirection {		enum class SwipeDirection(val orientation: Orientation) {
	Up,		Up(Orientation.Vertical),
	Down,		Down(Orientation.Vertical),
	Left,		Left(Orientation.Horizontal),
	Right,		Right(Orientation.Horizontal),
	}		}

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

+62 −16

Original line number	Original line	Diff line number	Diff line
	@@ -22,8 +22,6 @@ import androidx.compose.animation.core.Animatable
	import androidx.compose.animation.core.Spring		import androidx.compose.animation.core.Spring
	import androidx.compose.animation.core.spring		import androidx.compose.animation.core.spring
	import androidx.compose.foundation.gestures.Orientation		import androidx.compose.foundation.gestures.Orientation
	import androidx.compose.foundation.gestures.draggable
	import androidx.compose.foundation.gestures.rememberDraggableState
	import androidx.compose.runtime.Composable		import androidx.compose.runtime.Composable
	import androidx.compose.runtime.DisposableEffect		import androidx.compose.runtime.DisposableEffect
	import androidx.compose.runtime.getValue		import androidx.compose.runtime.getValue
	@@ -55,7 +53,7 @@ internal fun Modifier.swipeToScene(

	/** Whether swipe should be enabled in the given [orientation]. */		/** Whether swipe should be enabled in the given [orientation]. */
	fun Scene.shouldEnableSwipes(orientation: Orientation): Boolean =		fun Scene.shouldEnableSwipes(orientation: Orientation): Boolean =
	upOrLeft(orientation) != null \|\| downOrRight(orientation) != null		userActions.keys.any { it is Swipe && it.direction.orientation == orientation }

	val currentScene = gestureHandler.currentScene		val currentScene = gestureHandler.currentScene
	val canSwipe = currentScene.shouldEnableSwipes(orientation)		val canSwipe = currentScene.shouldEnableSwipes(orientation)
	@@ -68,8 +66,7 @@ internal fun Modifier.swipeToScene(
	)		)

	return nestedScroll(connection = gestureHandler.nestedScroll.connection)		return nestedScroll(connection = gestureHandler.nestedScroll.connection)
	.draggable(		.multiPointerDraggable(
	state = rememberDraggableState(onDelta = gestureHandler.draggable::onDelta),
	orientation = orientation,		orientation = orientation,
	enabled = gestureHandler.isDrivingTransition \|\| canSwipe,		enabled = gestureHandler.isDrivingTransition \|\| canSwipe,
	// Immediately start the drag if this our [transition] is currently animating to a scene		// Immediately start the drag if this our [transition] is currently animating to a scene
	@@ -80,6 +77,7 @@ internal fun Modifier.swipeToScene(
	gestureHandler.isAnimatingOffset &&		gestureHandler.isAnimatingOffset &&
	!canOppositeSwipe,		!canOppositeSwipe,
	onDragStarted = gestureHandler.draggable::onDragStarted,		onDragStarted = gestureHandler.draggable::onDragStarted,
			onDragDelta = gestureHandler.draggable::onDelta,
	onDragStopped = gestureHandler.draggable::onDragStopped,		onDragStopped = gestureHandler.draggable::onDragStopped,
	)		)
	}		}
	@@ -159,7 +157,7 @@ class SceneGestureHandler(

	internal var gestureWithPriority: Any? = null		internal var gestureWithPriority: Any? = null

	internal fun onDragStarted() {		internal fun onDragStarted(pointersDown: Int) {
	if (isDrivingTransition) {		if (isDrivingTransition) {
	// This [transition] was already driving the animation: simply take over it.		// This [transition] was already driving the animation: simply take over it.
	// Stop animating and start from where the current offset.		// Stop animating and start from where the current offset.
	@@ -199,6 +197,26 @@ class SceneGestureHandler(
	Orientation.Vertical -> layoutImpl.size.height		Orientation.Vertical -> layoutImpl.size.height
	}.toFloat()		}.toFloat()

			swipeTransition.actionUpOrLeft =
			Swipe(
			direction =
			when (orientation) {
			Orientation.Horizontal -> SwipeDirection.Left
			Orientation.Vertical -> SwipeDirection.Up
			},
			pointerCount = pointersDown,
			)

			swipeTransition.actionDownOrRight =
			Swipe(
			direction =
			when (orientation) {
			Orientation.Horizontal -> SwipeDirection.Right
			Orientation.Vertical -> SwipeDirection.Down
			},
			pointerCount = pointersDown,
			)

	if (swipeTransition.absoluteDistance > 0f) {		if (swipeTransition.absoluteDistance > 0f) {
	transitionState = swipeTransition		transitionState = swipeTransition
	}		}
	@@ -246,11 +264,15 @@ class SceneGestureHandler(
	// to the next screen or go back to the previous one.		// to the next screen or go back to the previous one.
	val offset = swipeTransition.dragOffset		val offset = swipeTransition.dragOffset
	val absoluteDistance = swipeTransition.absoluteDistance		val absoluteDistance = swipeTransition.absoluteDistance
	if (offset <= -absoluteDistance && fromScene.upOrLeft(orientation) == toScene.key) {		if (
			offset <= -absoluteDistance &&
			fromScene.userActions[swipeTransition.actionUpOrLeft] == toScene.key
			) {
	swipeTransition.dragOffset += absoluteDistance		swipeTransition.dragOffset += absoluteDistance
	swipeTransition._fromScene = toScene		swipeTransition._fromScene = toScene
	} else if (		} else if (
	offset >= absoluteDistance && fromScene.downOrRight(orientation) == toScene.key		offset >= absoluteDistance &&
			fromScene.userActions[swipeTransition.actionDownOrRight] == toScene.key
	) {		) {
	swipeTransition.dragOffset -= absoluteDistance		swipeTransition.dragOffset -= absoluteDistance
	swipeTransition._fromScene = toScene		swipeTransition._fromScene = toScene
	@@ -272,8 +294,8 @@ class SceneGestureHandler(
	Orientation.Vertical -> layoutImpl.size.height		Orientation.Vertical -> layoutImpl.size.height
	}.toFloat()		}.toFloat()

	val upOrLeft = upOrLeft(orientation)		val upOrLeft = userActions[swipeTransition.actionUpOrLeft]
	val downOrRight = downOrRight(orientation)		val downOrRight = userActions[swipeTransition.actionDownOrRight]

	// Compute the target scene depending on the current offset.		// Compute the target scene depending on the current offset.
	return when {		return when {
	@@ -516,6 +538,10 @@ class SceneGestureHandler(
	var _distance by mutableFloatStateOf(0f)		var _distance by mutableFloatStateOf(0f)
	val distance: Float		val distance: Float
	get() = _distance		get() = _distance

			/** The [UserAction]s associated to this swipe. */
			var actionUpOrLeft: UserAction = Back
			var actionDownOrRight: UserAction = Back
	}		}

	companion object {		companion object {
	@@ -526,9 +552,9 @@ class SceneGestureHandler(
	private class SceneDraggableHandler(		private class SceneDraggableHandler(
	private val gestureHandler: SceneGestureHandler,		private val gestureHandler: SceneGestureHandler,
	) : DraggableHandler {		) : DraggableHandler {
	override suspend fun onDragStarted(coroutineScope: CoroutineScope, startedPosition: Offset) {		override fun onDragStarted(startedPosition: Offset, pointersDown: Int) {
	gestureHandler.gestureWithPriority = this		gestureHandler.gestureWithPriority = this
	gestureHandler.onDragStarted()		gestureHandler.onDragStarted(pointersDown)
	}		}

	override fun onDelta(pixels: Float) {		override fun onDelta(pixels: Float) {
	@@ -537,7 +563,7 @@ private class SceneDraggableHandler(
	}		}
	}		}

	override suspend fun onDragStopped(coroutineScope: CoroutineScope, velocity: Float) {		override fun onDragStopped(velocity: Float) {
	if (gestureHandler.gestureWithPriority == this) {		if (gestureHandler.gestureWithPriority == this) {
	gestureHandler.gestureWithPriority = null		gestureHandler.gestureWithPriority = null
	gestureHandler.onDragStopped(velocity = velocity, canChangeScene = true)		gestureHandler.onDragStopped(velocity = velocity, canChangeScene = true)
	@@ -580,11 +606,31 @@ class SceneNestedScrollHandler(
	// moving on to the next scene.		// moving on to the next scene.
	var gestureStartedOnNestedChild = false		var gestureStartedOnNestedChild = false

			val actionUpOrLeft =
			Swipe(
			direction =
			when (gestureHandler.orientation) {
			Orientation.Horizontal -> SwipeDirection.Left
			Orientation.Vertical -> SwipeDirection.Up
			},
			pointerCount = 1,
			)

			val actionDownOrRight =
			Swipe(
			direction =
			when (gestureHandler.orientation) {
			Orientation.Horizontal -> SwipeDirection.Right
			Orientation.Vertical -> SwipeDirection.Down
			},
			pointerCount = 1,
			)

	fun findNextScene(amount: Float): SceneKey? {		fun findNextScene(amount: Float): SceneKey? {
	val fromScene = gestureHandler.currentScene		val fromScene = gestureHandler.currentScene
	return when {		return when {
	amount < 0f -> fromScene.upOrLeft(gestureHandler.orientation)		amount < 0f -> fromScene.userActions[actionUpOrLeft]
	amount > 0f -> fromScene.downOrRight(gestureHandler.orientation)		amount > 0f -> fromScene.userActions[actionDownOrRight]
	else -> null		else -> null
	}		}
	}		}
	@@ -625,7 +671,7 @@ class SceneNestedScrollHandler(
	onStart = {		onStart = {
	gestureHandler.gestureWithPriority = this		gestureHandler.gestureWithPriority = this
	priorityScene = nextScene		priorityScene = nextScene
	gestureHandler.onDragStarted()		gestureHandler.onDragStarted(pointersDown = 1)
	},		},
	onScroll = { offsetAvailable ->		onScroll = { offsetAvailable ->
	if (gestureHandler.gestureWithPriority != this) {		if (gestureHandler.gestureWithPriority != this) {