Merge "Remove unused PriorityNestedScrollConnection constructor" into main (fa312e81) · Commits · e / os / android_frameworks_base

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

+38 −67

Original line number	Diff line number	Diff line
		@@ -34,71 +34,76 @@ internal typealias SuspendedValue<T> = suspend () -> T
		* Note: Call [reset] before destroying this object to make sure you always get a call to [onStop]
		* after [onStart].
		*
		* @sample com.android.compose.animation.scene.rememberSwipeToSceneNestedScrollConnection
		* @sample LargeTopAppBarNestedScrollConnection
		* @sample com.android.compose.animation.scene.NestedScrollHandlerImpl.nestedScrollConnection
		*/
		class PriorityNestedScrollConnection(
		private val canStartPreScroll: (offsetAvailable: Offset, offsetBeforeStart: Offset) -> Boolean,
		private val canStartPostScroll: (offsetAvailable: Offset, offsetBeforeStart: Offset) -> Boolean,
		private val canStartPostFling: (velocityAvailable: Velocity) -> Boolean,
		orientation: Orientation,
		private val canStartPreScroll: (offsetAvailable: Float, offsetBeforeStart: Float) -> Boolean,
		private val canStartPostScroll: (offsetAvailable: Float, offsetBeforeStart: Float) -> Boolean,
		private val canStartPostFling: (velocityAvailable: Float) -> Boolean,
		private val canContinueScroll: (source: NestedScrollSource) -> Boolean,
		private val canScrollOnFling: Boolean,
		private val onStart: (offsetAvailable: Offset) -> Unit,
		private val onScroll: (offsetAvailable: Offset) -> Offset,
		private val onStop: (velocityAvailable: Velocity) -> SuspendedValue<Velocity>,
		) : NestedScrollConnection {
		private val onStart: (offsetAvailable: Float) -> Unit,
		private val onScroll: (offsetAvailable: Float) -> Float,
		private val onStop: (velocityAvailable: Float) -> SuspendedValue<Float>,
		) : NestedScrollConnection, SpaceVectorConverter by SpaceVectorConverter(orientation) {

		/** In priority mode [onPreScroll] events are first consumed by the parent, via [onScroll]. */
		private var isPriorityMode = false

		private var offsetScrolledBeforePriorityMode = Offset.Zero
		private var offsetScrolledBeforePriorityMode = 0f

		override fun onPostScroll(
		consumed: Offset,
		available: Offset,
		source: NestedScrollSource,
		): Offset {
		val availableFloat = available.toFloat()
		// The offset before the start takes into account the up and down movements, starting from
		// the beginning or from the last fling gesture.
		val offsetBeforeStart = offsetScrolledBeforePriorityMode - available
		val offsetBeforeStart = offsetScrolledBeforePriorityMode - availableFloat

		if (
		isPriorityMode \|\|
		(source == NestedScrollSource.SideEffect && !canScrollOnFling) \|\|
		!canStartPostScroll(available, offsetBeforeStart)
		!canStartPostScroll(availableFloat, offsetBeforeStart)
		) {
		// The priority mode cannot start so we won't consume the available offset.
		return Offset.Zero
		}

		return onPriorityStart(available)
		return onPriorityStart(availableFloat).toOffset()
		}

		override fun onPreScroll(available: Offset, source: NestedScrollSource): Offset {
		if (!isPriorityMode) {
		if (source == NestedScrollSource.UserInput \|\| canScrollOnFling) {
		if (canStartPreScroll(available, offsetScrolledBeforePriorityMode)) {
		return onPriorityStart(available)
		val availableFloat = available.toFloat()
		if (canStartPreScroll(availableFloat, offsetScrolledBeforePriorityMode)) {
		return onPriorityStart(availableFloat).toOffset()
		}
		// We want to track the amount of offset consumed before entering priority mode
		offsetScrolledBeforePriorityMode += available
		offsetScrolledBeforePriorityMode += availableFloat
		}

		return Offset.Zero
		}

		val availableFloat = available.toFloat()
		if (!canContinueScroll(source)) {
		// Step 3a: We have lost priority and we no longer need to intercept scroll events.
		onPriorityStop(velocity = Velocity.Zero)
		onPriorityStop(velocity = 0f)

		// We've just reset offsetScrolledBeforePriorityMode to Offset.Zero
		// We've just reset offsetScrolledBeforePriorityMode to 0f
		// We want to track the amount of offset consumed before entering priority mode
		offsetScrolledBeforePriorityMode += available
		offsetScrolledBeforePriorityMode += availableFloat

		return Offset.Zero
		}

		// Step 2: We have the priority and can consume the scroll events.
		return onScroll(available)
		return onScroll(availableFloat).toOffset()
		}

		override suspend fun onPreFling(available: Velocity): Velocity {
		@@ -108,15 +113,16 @@ class PriorityNestedScrollConnection(
		}
		// Step 3b: The finger is lifted, we can stop intercepting scroll events and use the speed
		// of the fling gesture.
		return onPriorityStop(velocity = available).invoke()
		return onPriorityStop(velocity = available.toFloat()).invoke().toVelocity()
		}

		override suspend fun onPostFling(consumed: Velocity, available: Velocity): Velocity {
		val availableFloat = available.toFloat()
		if (isPriorityMode) {
		return onPriorityStop(velocity = available).invoke()
		return onPriorityStop(velocity = availableFloat).invoke().toVelocity()
		}

		if (!canStartPostFling(available)) {
		if (!canStartPostFling(availableFloat)) {
		return Velocity.Zero
		}

		@@ -124,11 +130,11 @@ class PriorityNestedScrollConnection(
		// given the available velocity.
		// TODO(b/291053278): Remove canStartPostFling() and instead make it possible to define the
		// overscroll behavior on the Scene level.
		val smallOffset = Offset(available.x.sign, available.y.sign)
		onPriorityStart(available = smallOffset)
		val smallOffset = availableFloat.sign
		onPriorityStart(availableOffset = smallOffset)

		// This is the last event of a scroll gesture.
		return onPriorityStop(available).invoke()
		return onPriorityStop(availableFloat).invoke().toVelocity()
		}

		/**
		@@ -138,10 +144,10 @@ class PriorityNestedScrollConnection(
		*/
		fun reset() {
		// Step 3c: To ensure that an onStop is always called for every onStart.
		onPriorityStop(velocity = Velocity.Zero)
		onPriorityStop(velocity = 0f)
		}

		private fun onPriorityStart(available: Offset): Offset {
		private fun onPriorityStart(availableOffset: Float): Float {
		if (isPriorityMode) {
		error("This should never happen, onPriorityStart() was called when isPriorityMode")
		}
		@@ -152,17 +158,17 @@ class PriorityNestedScrollConnection(

		// Note: onStop will be called if we cannot continue to scroll (step 3a), or the finger is
		// lifted (step 3b), or this object has been destroyed (step 3c).
		onStart(available)
		onStart(availableOffset)

		return onScroll(available)
		return onScroll(availableOffset)
		}

		private fun onPriorityStop(velocity: Velocity): SuspendedValue<Velocity> {
		private fun onPriorityStop(velocity: Float): SuspendedValue<Float> {
		// We can restart tracking the consumed offsets from scratch.
		offsetScrolledBeforePriorityMode = Offset.Zero
		offsetScrolledBeforePriorityMode = 0f

		if (!isPriorityMode) {
		return { Velocity.Zero }
		return { 0f }
		}

		isPriorityMode = false
		@@ -170,38 +176,3 @@ class PriorityNestedScrollConnection(
		return onStop(velocity)
		}
		}

		fun PriorityNestedScrollConnection(
		orientation: Orientation,
		canStartPreScroll: (offsetAvailable: Float, offsetBeforeStart: Float) -> Boolean,
		canStartPostScroll: (offsetAvailable: Float, offsetBeforeStart: Float) -> Boolean,
		canStartPostFling: (velocityAvailable: Float) -> Boolean,
		canContinueScroll: (source: NestedScrollSource) -> Boolean,
		canScrollOnFling: Boolean,
		onStart: (offsetAvailable: Float) -> Unit,
		onScroll: (offsetAvailable: Float) -> Float,
		onStop: (velocityAvailable: Float) -> SuspendedValue<Float>,
		) =
		with(SpaceVectorConverter(orientation)) {
		PriorityNestedScrollConnection(
		canStartPreScroll = { offsetAvailable: Offset, offsetBeforeStart: Offset ->
		canStartPreScroll(offsetAvailable.toFloat(), offsetBeforeStart.toFloat())
		},
		canStartPostScroll = { offsetAvailable: Offset, offsetBeforeStart: Offset ->
		canStartPostScroll(offsetAvailable.toFloat(), offsetBeforeStart.toFloat())
		},
		canStartPostFling = { velocityAvailable: Velocity ->
		canStartPostFling(velocityAvailable.toFloat())
		},
		canContinueScroll = canContinueScroll,
		canScrollOnFling = canScrollOnFling,
		onStart = { offsetAvailable -> onStart(offsetAvailable.toFloat()) },
		onScroll = { offsetAvailable: Offset ->
		onScroll(offsetAvailable.toFloat()).toOffset()
		},
		onStop = { velocityAvailable: Velocity ->
		val consumedVelocity = onStop(velocityAvailable.toFloat())
		suspend { consumedVelocity.invoke().toVelocity() }
		},
		)
		}

packages/SystemUI/compose/scene/tests/src/com/android/compose/nestedscroll/PriorityNestedScrollConnectionTest.kt

+26 −29

Original line number	Diff line number	Diff line
		@@ -18,8 +18,9 @@

		package com.android.compose.nestedscroll

		import androidx.compose.foundation.gestures.Orientation
		import androidx.compose.ui.geometry.Offset
		import androidx.compose.ui.input.nestedscroll.NestedScrollSource
		import androidx.compose.ui.input.nestedscroll.NestedScrollSource.Companion.UserInput
		import androidx.compose.ui.unit.Velocity
		import androidx.test.ext.junit.runners.AndroidJUnit4
		import com.google.common.truth.Truth.assertThat
		@@ -35,13 +36,14 @@ class PriorityNestedScrollConnectionTest {
		private var canStartPostFling = false
		private var canContinueScroll = false
		private var isStarted = false
		private var lastScroll: Offset? = null
		private var returnOnScroll = Offset.Zero
		private var lastStop: Velocity? = null
		private var returnOnStop = Velocity.Zero
		private var lastScroll: Float? = null
		private var returnOnScroll = 0f
		private var lastStop: Float? = null
		private var returnOnStop = 0f

		private val scrollConnection =
		PriorityNestedScrollConnection(
		orientation = Orientation.Vertical,
		canStartPreScroll = { _, _ -> canStartPreScroll },
		canStartPostScroll = { _, _ -> canStartPostScroll },
		canStartPostFling = { canStartPostFling },
		@@ -58,11 +60,6 @@ class PriorityNestedScrollConnectionTest {
		},
		)

		private val offset1 = Offset(1f, 1f)
		private val offset2 = Offset(2f, 2f)
		private val velocity1 = Velocity(1f, 1f)
		private val velocity2 = Velocity(2f, 2f)

		@Test
		fun step1_priorityModeShouldStartOnlyOnPreScroll() = runTest {
		canStartPreScroll = true
		@@ -70,7 +67,7 @@ class PriorityNestedScrollConnectionTest {
		scrollConnection.onPostScroll(
		consumed = Offset.Zero,
		available = Offset.Zero,
		source = NestedScrollSource.Drag,
		source = UserInput,
		)
		assertThat(isStarted).isEqualTo(false)

		@@ -80,7 +77,7 @@ class PriorityNestedScrollConnectionTest {
		scrollConnection.onPostFling(consumed = Velocity.Zero, available = Velocity.Zero)
		assertThat(isStarted).isEqualTo(false)

		scrollConnection.onPreScroll(available = Offset.Zero, source = NestedScrollSource.Drag)
		scrollConnection.onPreScroll(available = Offset.Zero, source = UserInput)
		assertThat(isStarted).isEqualTo(true)
		}

		@@ -89,7 +86,7 @@ class PriorityNestedScrollConnectionTest {
		scrollConnection.onPostScroll(
		consumed = Offset.Zero,
		available = Offset.Zero,
		source = NestedScrollSource.Drag,
		source = UserInput,
		)
		}

		@@ -97,7 +94,7 @@ class PriorityNestedScrollConnectionTest {
		fun step1_priorityModeShouldStartOnlyOnPostScroll() = runTest {
		canStartPostScroll = true

		scrollConnection.onPreScroll(available = Offset.Zero, source = NestedScrollSource.Drag)
		scrollConnection.onPreScroll(available = Offset.Zero, source = UserInput)
		assertThat(isStarted).isEqualTo(false)

		scrollConnection.onPreFling(available = Velocity.Zero)
		@@ -115,7 +112,7 @@ class PriorityNestedScrollConnectionTest {
		scrollConnection.onPostScroll(
		consumed = Offset.Zero,
		available = Offset.Zero,
		source = NestedScrollSource.Drag,
		source = UserInput,
		)
		assertThat(isStarted).isEqualTo(false)

		@@ -128,12 +125,12 @@ class PriorityNestedScrollConnectionTest {
		canStartPostScroll = true

		scrollConnection.onPostScroll(
		consumed = offset1,
		available = offset2,
		source = NestedScrollSource.Drag,
		consumed = Offset(1f, 1f),
		available = Offset(2f, 2f),
		source = UserInput,
		)

		assertThat(lastScroll).isEqualTo(offset2)
		assertThat(lastScroll).isEqualTo(2f)
		}

		@Test
		@@ -141,13 +138,13 @@ class PriorityNestedScrollConnectionTest {
		startPriorityModePostScroll()
		canContinueScroll = true

		scrollConnection.onPreScroll(available = offset1, source = NestedScrollSource.Drag)
		assertThat(lastScroll).isEqualTo(offset1)
		scrollConnection.onPreScroll(available = Offset(1f, 1f), source = UserInput)
		assertThat(lastScroll).isEqualTo(1f)

		canContinueScroll = false
		scrollConnection.onPreScroll(available = offset2, source = NestedScrollSource.Drag)
		assertThat(lastScroll).isNotEqualTo(offset2)
		assertThat(lastScroll).isEqualTo(offset1)
		scrollConnection.onPreScroll(available = Offset(2f, 2f), source = UserInput)
		assertThat(lastScroll).isNotEqualTo(2f)
		assertThat(lastScroll).isEqualTo(1f)
		}

		@Test
		@@ -155,7 +152,7 @@ class PriorityNestedScrollConnectionTest {
		startPriorityModePostScroll()
		canContinueScroll = false

		scrollConnection.onPreScroll(available = Offset.Zero, source = NestedScrollSource.Drag)
		scrollConnection.onPreScroll(available = Offset.Zero, source = UserInput)

		assertThat(lastStop).isNotNull()
		}
		@@ -184,22 +181,22 @@ class PriorityNestedScrollConnectionTest {
		fun receive_onPostFling() = runTest {
		canStartPostFling = true

		scrollConnection.onPostFling(consumed = velocity1, available = velocity2)
		scrollConnection.onPostFling(consumed = Velocity(1f, 1f), available = Velocity(2f, 2f))

		assertThat(lastStop).isEqualTo(velocity2)
		assertThat(lastStop).isEqualTo(2f)
		}

		@Test
		fun step1_priorityModeShouldStartOnlyOnPostFling() = runTest {
		canStartPostFling = true

		scrollConnection.onPreScroll(available = Offset.Zero, source = NestedScrollSource.Drag)
		scrollConnection.onPreScroll(available = Offset.Zero, source = UserInput)
		assertThat(isStarted).isEqualTo(false)

		scrollConnection.onPostScroll(
		consumed = Offset.Zero,
		available = Offset.Zero,
		source = NestedScrollSource.Drag,
		source = UserInput,
		)
		assertThat(isStarted).isEqualTo(false)