Merge "SwipeToDismiss with MotionValue" into main (fb2a0e97) · Commits · e / os / android_frameworks_base

packages/SystemUI/compose/core/Android.bp

+1 −0

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		@@ -40,6 +40,7 @@ android_library {
		"androidx.savedstate_savedstate",
		"androidx.window_window",
		"//frameworks/libs/systemui:tracinglib-platform",
		"//frameworks/libs/systemui:mechanics",
		],

		kotlincflags: [

packages/SystemUI/compose/core/src/com/android/compose/gesture/NestedDraggable.kt

+1 −1

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		@@ -205,7 +205,7 @@ private data class NestedDraggableElement(
		* A root node on top of [NestedDraggableNode] so that no [PointerInputModifierNode] is installed
		* when this draggable is disabled.
		*/
		private class NestedDraggableRootNode(
		internal class NestedDraggableRootNode(
		draggable: NestedDraggable,
		orientation: Orientation,
		overscrollEffect: OverscrollEffect?,

packages/SystemUI/compose/core/src/com/android/compose/gesture/OverscrollToDismiss.kt

0 → 100644

+221 −0

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		/*
		* Copyright (C) 2025 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.gesture

		import androidx.compose.foundation.gestures.Orientation
		import androidx.compose.ui.Modifier
		import androidx.compose.ui.geometry.Offset
		import androidx.compose.ui.input.pointer.PointerType
		import androidx.compose.ui.layout.Measurable
		import androidx.compose.ui.layout.MeasureResult
		import androidx.compose.ui.layout.MeasureScope
		import androidx.compose.ui.node.CompositionLocalConsumerModifierNode
		import androidx.compose.ui.node.DelegatingNode
		import androidx.compose.ui.node.LayoutModifierNode
		import androidx.compose.ui.node.ModifierNodeElement
		import androidx.compose.ui.node.ObserverModifierNode
		import androidx.compose.ui.node.currentValueOf
		import androidx.compose.ui.node.observeReads
		import androidx.compose.ui.node.requireDensity
		import androidx.compose.ui.platform.InspectorInfo
		import androidx.compose.ui.platform.LocalViewConfiguration
		import androidx.compose.ui.unit.Constraints
		import androidx.compose.ui.unit.dp
		import com.android.mechanics.DistanceGestureContext
		import com.android.mechanics.MotionValue
		import com.android.mechanics.debug.findMotionValueDebugger
		import com.android.mechanics.effects.MagneticDetach
		import com.android.mechanics.effects.MagneticDetach.Companion.Defaults.AttachDetachState
		import com.android.mechanics.spec.InputDirection
		import com.android.mechanics.spec.SemanticKey
		import com.android.mechanics.spec.builder.MotionBuilderContext
		import com.android.mechanics.spec.builder.fixedSpatialValueSpec
		import com.android.mechanics.spec.builder.spatialMotionSpec
		import com.android.mechanics.spec.with
		import com.android.mechanics.spring.SpringParameters
		import kotlin.math.abs
		import kotlin.math.sign
		import kotlinx.coroutines.Job
		import kotlinx.coroutines.launch

		/**
		* "Swipe to dismiss" effect that supports nested scrolling.
		*
		* TODO: Once b/413283893 is done, motionBuilderContext can be read internally via
		* CompositionLocalConsumerModifierNode, instead of passing it.
		*/
		fun Modifier.overscrollToDismiss(
		motionBuilderContext: MotionBuilderContext,
		orientation: Orientation = Orientation.Horizontal,
		enabled: Boolean = true,
		onDismissed: () -> Unit,
		) = this.then(OverscrollToDismissElement(motionBuilderContext, orientation, enabled, onDismissed))

		private data class OverscrollToDismissElement(
		val motionBuilderContext: MotionBuilderContext,
		val orientation: Orientation,
		val enabled: Boolean,
		val onDismissed: () -> Unit,
		) : ModifierNodeElement<OverscrollToDismissNode>() {
		override fun create(): OverscrollToDismissNode {
		return OverscrollToDismissNode(orientation, enabled, motionBuilderContext, onDismissed)
		}

		override fun update(node: OverscrollToDismissNode) {
		node.update(orientation, enabled, onDismissed)
		}

		override fun InspectorInfo.inspectableProperties() {
		name = "overscrollToDismiss"
		properties["enabled"] = enabled
		properties["orientation"] = orientation
		}
		}

		private class OverscrollToDismissNode(
		orientation: Orientation,
		enabled: Boolean,
		var motionBuilderContext: MotionBuilderContext,
		var onDismissed: () -> Unit,
		) :
		DelegatingNode(),
		LayoutModifierNode,
		CompositionLocalConsumerModifierNode,
		ObserverModifierNode,
		NestedDraggable,
		NestedDraggable.Controller {

		// This implementation always tracks the gesture from 0..x, independent of whether the
		// overscroll is positive or negative. Thus, the output needs to be multiplied by this sign to
		// compute the actual value.
		private var overscrollSign: Float = 0f
		private val gestureContext =
		DistanceGestureContext(0f, InputDirection.Max, directionChangeSlop = 1f)

		private val motionValue =
		MotionValue(
		gestureContext::dragOffset,
		gestureContext,
		motionBuilderContext.fixedSpatialValueSpec(0f),
		)

		private var delegateNode =
		delegate(NestedDraggableRootNode(this, orientation, null, enabled, true))

		fun update(orientation: Orientation, enabled: Boolean, onDismissed: () -> Unit) {
		this.onDismissed = onDismissed
		delegateNode.update(this, orientation, null, enabled, true)
		}

		private var contentBoxWidth = 0
		private var motionValueJob: Job? = null

		override fun onAttach() {
		onObservedReadsChanged()
		motionValueJob = coroutineScope.launch { keepRunningUntilDismissed() }
		}

		override fun onObservedReadsChanged() {
		observeReads {
		gestureContext.directionChangeSlop = currentValueOf(LocalViewConfiguration).touchSlop
		}
		}

		override fun onDetach() {
		motionValueJob?.cancel()
		}

		override fun MeasureScope.measure(
		measurable: Measurable,
		constraints: Constraints,
		): MeasureResult {
		val placeable = measurable.measure(constraints)
		contentBoxWidth = placeable.measuredWidth
		return layout(placeable.measuredWidth, placeable.measuredHeight) {
		placeable.place((motionValue.output * overscrollSign).toInt(), 0)
		}
		}

		override val autoStopNestedDrags: Boolean
		get() = true

		override fun onDragStarted(
		position: Offset,
		sign: Float,
		pointersDown: Int,
		pointerType: PointerType?,
		): NestedDraggable.Controller {
		overscrollSign = sign
		gestureContext.reset(dragOffset = motionValue.output, direction = InputDirection.Max)
		motionValue.spec = motionBuilderContext.spatialMotionSpec { at(0f, MagneticDetach()) }
		return this
		}

		override fun shouldConsumeNestedPreScroll(sign: Float): Boolean {
		return motionValue[isDismissedState] ?: false
		}

		override fun onDrag(delta: Float): Float {
		val previousOffset = gestureContext.dragOffset
		val currentOffset = (gestureContext.dragOffset + delta * overscrollSign).coerceAtLeast(0f)
		gestureContext.dragOffset = currentOffset
		return (currentOffset - previousOffset) * overscrollSign
		}

		override suspend fun onDragStopped(velocity: Float, awaitFling: suspend () -> Unit): Float {
		val currentState = motionValue[AttachDetachState]
		with(requireDensity()) {
		val isFlingInOppositeDirection =
		abs(velocity) > AbortVelocity.toPx() && velocity.sign != overscrollSign

		val settleAttached =
		currentState == MagneticDetach.State.Attached \|\|
		(currentState == MagneticDetach.State.Detached && isFlingInOppositeDirection)

		motionValue.spec =
		if (settleAttached) {
		motionBuilderContext.fixedSpatialValueSpec(0f, SnapBackSpring)
		} else {
		motionBuilderContext.fixedSpatialValueSpec(
		contentBoxWidth.toFloat(),
		SnapBackSpring,
		listOf(isDismissedState with true),
		)
		}
		}
		return velocity
		}

		private suspend fun keepRunningUntilDismissed() {
		val debuggerHandle = findMotionValueDebugger()?.register(motionValue)
		try {
		motionValue.keepRunningWhile {
		val isDismissed = get(isDismissedState) ?: false
		!(isDismissed && isStable)
		}
		onDismissed()
		} finally {
		debuggerHandle?.dispose()
		}
		}

		companion object {
		val isDismissedState = SemanticKey<Boolean>("isDismissed")
		val AbortVelocity = 100.dp // dp/s
		val SnapBackSpring = SpringParameters(stiffness = 550f, dampingRatio = 0.95f)
		}
		}

packages/SystemUI/compose/core/tests/Android.bp

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		@@ -35,6 +35,8 @@ android_test {

		static_libs: [
		"PlatformComposeCore",
		"PlatformMotionTestingCompose",
		"platform-test-annotations",

		"androidx.test.runner",
		"androidx.test.ext.junit",
		@@ -45,6 +47,7 @@ android_test {

		"truth",
		],
		asset_dirs: ["goldens"],

		kotlincflags: ["-Xjvm-default=all"],
		use_resource_processor: true,

packages/SystemUI/compose/core/tests/AndroidManifest.xml

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		@@ -23,7 +23,7 @@

		<activity
		android:name="androidx.activity.ComponentActivity"
		android:theme="@android:style/Theme.DeviceDefault.DayNight"
		android:theme="@android:style/Theme.DeviceDefault.NoActionBar"
		android:exported="true"
		tools:replace="android:theme" />
		</application>