STL ElementStateScope exposes approachSize() (e944f379) · Commits · e / os / android_frameworks_base

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

+28 −3

Original line number	Diff line number	Diff line
		@@ -52,6 +52,7 @@ import androidx.compose.ui.util.fastForEach
		import androidx.compose.ui.util.fastForEachIndexed
		import androidx.compose.ui.util.fastForEachReversed
		import androidx.compose.ui.util.lerp
		import com.android.compose.animation.scene.Element.Companion.SizeUnspecified
		import com.android.compose.animation.scene.content.Content
		import com.android.compose.animation.scene.content.state.TransitionState
		import com.android.compose.animation.scene.transformation.CustomPropertyTransformation
		@@ -105,6 +106,13 @@ internal class Element(val key: ElementKey) {
		var targetSize by mutableStateOf(SizeUnspecified)
		var targetOffset by mutableStateOf(Offset.Unspecified)

		/**
		* The approach state of this element in this content, i.e. the intermediate layout state
		* during transitions, used for smooth animation. Note: These values are computed before
		* measuring the children.
		*/
		var approachSize by mutableStateOf(SizeUnspecified)

		/** The last state this element had in this content. */
		var lastOffset = Offset.Unspecified
		var lastSize = SizeUnspecified
		@@ -340,7 +348,11 @@ internal class ElementNode(
		override fun isMeasurementApproachInProgress(lookaheadSize: IntSize): Boolean {
		// TODO(b/324191441): Investigate whether making this check more complex (checking if this
		// element is shared or transformed) would lead to better performance.
		return isAnyStateTransitioning()
		val isTransitioning = isAnyStateTransitioning()
		if (!isTransitioning) {
		stateInContent.approachSize = SizeUnspecified
		}
		return isTransitioning
		}

		override fun Placeable.PlacementScope.isPlacementApproachInProgress(
		@@ -392,6 +404,7 @@ internal class ElementNode(
		// sharedElement isn't part of either but the element is still rendered as part of
		// the underlying scene that is currently not being transitioned.
		val currentState = currentTransitionStates.last().last()
		stateInContent.approachSize = Element.SizeUnspecified
		val shouldPlaceInThisContent =
		elementContentWhenIdle(
		layoutImpl,
		@@ -409,7 +422,14 @@ internal class ElementNode(
		val transition = elementState as? TransitionState.Transition

		val placeable =
		measure(layoutImpl, element, transition, stateInContent, measurable, constraints)
		approachMeasure(
		layoutImpl = layoutImpl,
		element = element,
		transition = transition,
		stateInContent = stateInContent,
		measurable = measurable,
		constraints = constraints,
		)
		stateInContent.lastSize = placeable.size()
		return layout(placeable.width, placeable.height) { place(elementState, placeable) }
		}
		@@ -1183,7 +1203,7 @@ private fun interruptedAlpha(
		)
		}

		private fun measure(
		private fun approachMeasure(
		layoutImpl: SceneTransitionLayoutImpl,
		element: Element,
		transition: TransitionState.Transition?,
		@@ -1214,6 +1234,7 @@ private fun measure(
		maybePlaceable?.let { placeable ->
		stateInContent.sizeBeforeInterruption = Element.SizeUnspecified
		stateInContent.sizeInterruptionDelta = IntSize.Zero
		stateInContent.approachSize = Element.SizeUnspecified
		return placeable
		}

		@@ -1236,6 +1257,10 @@ private fun measure(
		)
		},
		)

		// Important: Set approachSize before child measurement. Could be used for their calculations.
		stateInContent.approachSize = interruptedSize

		return measurable.measure(
		Constraints.fixed(
		interruptedSize.width.coerceAtLeast(0),

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

+7 −0

Original line number	Diff line number	Diff line
		@@ -159,6 +159,13 @@ interface ElementStateScope {
		*/
		fun ElementKey.targetSize(content: ContentKey): IntSize?

		/**
		* Return the approaching size of [this] element in the given [content], i.e. thethe size the
		* element when is transitioning, or `null` if the element is not composed and measured in that
		* content (yet).
		*/
		fun ElementKey.approachSize(content: ContentKey): IntSize?

		/**
		* Return the target offset of [this] element in the given [content], i.e. the size of the
		* element when idle, or `null` if the element is not composed and placed in that content (yet).

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

+6 −0

Original line number	Diff line number	Diff line
		@@ -31,6 +31,12 @@ internal class ElementStateScopeImpl(private val layoutImpl: SceneTransitionLayo
		}
		}

		override fun ElementKey.approachSize(content: ContentKey): IntSize? {
		return layoutImpl.elements[this]?.stateByContent?.get(content)?.approachSize.takeIf {
		it != Element.SizeUnspecified
		}
		}

		override fun ElementKey.targetOffset(content: ContentKey): Offset? {
		return layoutImpl.elements[this]?.stateByContent?.get(content)?.targetOffset.takeIf {
		it != Offset.Unspecified

packages/SystemUI/compose/scene/tests/src/com/android/compose/animation/scene/ElementTest.kt

+72 −0

Original line number	Diff line number	Diff line
		@@ -2312,4 +2312,76 @@ class ElementTest {

		assertThat(compositions).isEqualTo(1)
		}

		@Test
		fun measureElementApproachSizeBeforeChildren() {
		val state =
		rule.runOnUiThread {
		MutableSceneTransitionLayoutStateForTests(SceneA, SceneTransitions.Empty)
		}

		lateinit var fooHeight: () -> Dp?
		val fooHeightPreChildMeasure = mutableListOf<Dp?>()

		val scope =
		rule.setContentAndCreateMainScope {
		val density = LocalDensity.current
		SceneTransitionLayoutForTesting(state) {
		scene(SceneA) {
		fooHeight = {
		with(density) { TestElements.Foo.approachSize(SceneA)?.height?.toDp() }
		}
		Box(Modifier.element(TestElements.Foo).size(200.dp)) {
		Box(
		Modifier.approachLayout(
		isMeasurementApproachInProgress = { false },
		approachMeasure = { measurable, constraints ->
		fooHeightPreChildMeasure += fooHeight()
		measurable.measure(constraints).run {
		layout(width, height) {}
		}
		},
		)
		)
		}
		}
		scene(SceneB) { Box(Modifier.element(TestElements.Foo).size(100.dp)) }
		}
		}

		var progress by mutableFloatStateOf(0f)
		val transition = transition(from = SceneA, to = SceneB, progress = { progress })
		var countApproachPass = fooHeightPreChildMeasure.size

		// Idle state: Scene A.
		assertThat(state.isTransitioning()).isFalse()
		assertThat(fooHeight()).isNull()

		// Start transition: Scene A -> Scene B (progress 0%).
		scope.launch { state.startTransition(transition) }
		rule.waitForIdle()
		assertThat(state.isTransitioning()).isTrue()
		assertThat(fooHeightPreChildMeasure[countApproachPass]?.value).isWithin(.5f).of(200f)
		assertThat(fooHeight()).isNotNull()
		countApproachPass = fooHeightPreChildMeasure.size

		// progress 50%: height is going from 200dp to 100dp, so 150dp is expected now.
		progress = 0.5f
		rule.waitForIdle()
		assertThat(fooHeightPreChildMeasure[countApproachPass]?.value).isWithin(.5f).of(150f)
		assertThat(fooHeight()).isNotNull()
		countApproachPass = fooHeightPreChildMeasure.size

		progress = 1f
		rule.waitForIdle()
		assertThat(fooHeightPreChildMeasure[countApproachPass]?.value).isWithin(.5f).of(100f)
		assertThat(fooHeight()).isNotNull()
		countApproachPass = fooHeightPreChildMeasure.size

		transition.finish()
		rule.waitForIdle()
		assertThat(state.isTransitioning()).isFalse()
		assertThat(fooHeight()).isNull()
		assertThat(fooHeightPreChildMeasure.size).isEqualTo(countApproachPass)
		}
		}