Merge "Derive currentOverscrollSpec to avoid unnecessary layouts/placements" into main (f1d48b54) · Commits · e / os / android_frameworks_base

packages/SystemUI/compose/scene/src/com/android/compose/animation/scene/content/state/TransitionState.kt

+22 −10

Original line number	Diff line number	Diff line
		@@ -21,6 +21,7 @@ import androidx.compose.animation.core.AnimationVector1D
		import androidx.compose.animation.core.spring
		import androidx.compose.foundation.gestures.Orientation
		import androidx.compose.runtime.Stable
		import androidx.compose.runtime.State
		import androidx.compose.runtime.derivedStateOf
		import androidx.compose.runtime.getValue
		import com.android.compose.animation.scene.ContentKey
		@@ -249,18 +250,29 @@ sealed interface TransitionState {
		private var fromOverscrollSpec: OverscrollSpecImpl? = null
		private var toOverscrollSpec: OverscrollSpecImpl? = null

		/** The current [OverscrollSpecImpl], if this transition is currently overscrolling. */
		internal val currentOverscrollSpec: OverscrollSpecImpl?
		get() {
		if (this !is HasOverscrollProperties) return null
		/**
		* The current [OverscrollSpecImpl], if this transition is currently overscrolling.
		*
		* Note: This is backed by a State<OverscrollSpecImpl?> because the overscroll spec is
		* derived from progress, and we don't want readers of currentOverscrollSpec to recompose
		* every time progress is changed.
		*/
		private val _currentOverscrollSpec: State<OverscrollSpecImpl?>? =
		if (this !is HasOverscrollProperties) {
		null
		} else {
		derivedStateOf {
		val progress = progress
		val bouncingContent = bouncingContent
		return when {
		when {
		progress < 0f \|\| bouncingContent == fromContent -> fromOverscrollSpec
		progress > 1f \|\| bouncingContent == toContent -> toOverscrollSpec
		else -> null
		}
		}
		}
		internal val currentOverscrollSpec: OverscrollSpecImpl?
		get() = _currentOverscrollSpec?.value

		/**
		* An animatable that animates from 1f to 0f. This will be used to nicely animate the sudden

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

+60 −0

Original line number	Diff line number	Diff line
		@@ -46,6 +46,7 @@ import androidx.compose.ui.Alignment
		import androidx.compose.ui.Modifier
		import androidx.compose.ui.geometry.Offset
		import androidx.compose.ui.layout.approachLayout
		import androidx.compose.ui.layout.layout
		import androidx.compose.ui.platform.LocalViewConfiguration
		import androidx.compose.ui.platform.testTag
		import androidx.compose.ui.test.assertIsDisplayed
		@@ -70,11 +71,13 @@ import androidx.test.ext.junit.runners.AndroidJUnit4
		import com.android.compose.animation.scene.TestScenes.SceneA
		import com.android.compose.animation.scene.TestScenes.SceneB
		import com.android.compose.animation.scene.TestScenes.SceneC
		import com.android.compose.animation.scene.content.state.TransitionState
		import com.android.compose.animation.scene.subjects.assertThat
		import com.android.compose.test.assertSizeIsEqualTo
		import com.android.compose.test.setContentAndCreateMainScope
		import com.android.compose.test.transition
		import com.google.common.truth.Truth.assertThat
		import com.google.common.truth.Truth.assertWithMessage
		import kotlinx.coroutines.CoroutineScope
		import kotlinx.coroutines.launch
		import org.junit.Assert.assertThrows
		@@ -2581,4 +2584,61 @@ class ElementTest {
		}
		}
		}

		@Test
		fun staticSharedElementShouldNotRemeasureOrReplaceDuringOverscrollableTransition() {
		val size = 30.dp
		var numberOfMeasurements = 0
		var numberOfPlacements = 0

		// Foo is a simple element that does not move or resize during the transition.
		@Composable
		fun SceneScope.Foo(modifier: Modifier = Modifier) {
		Box(
		modifier
		.element(TestElements.Foo)
		.layout { measurable, constraints ->
		numberOfMeasurements++
		measurable.measure(constraints).run {
		numberOfPlacements++
		layout(width, height) { place(0, 0) }
		}
		}
		.size(size)
		)
		}

		val state = rule.runOnUiThread { MutableSceneTransitionLayoutState(SceneA) }
		val scope =
		rule.setContentAndCreateMainScope {
		SceneTransitionLayout(state) {
		scene(SceneA) { Box(Modifier.fillMaxSize()) { Foo() } }
		scene(SceneB) { Box(Modifier.fillMaxSize()) { Foo() } }
		}
		}

		// Start an overscrollable transition driven by progress.
		var progress by mutableFloatStateOf(0f)
		val transition = transition(from = SceneA, to = SceneB, progress = { progress })
		assertThat(transition).isInstanceOf(TransitionState.HasOverscrollProperties::class.java)
		scope.launch { state.startTransition(transition) }

		// Reset the counters after the first animation frame.
		rule.waitForIdle()
		numberOfMeasurements = 0
		numberOfPlacements = 0

		// Change the progress a bunch of times.
		val nFrames = 20
		repeat(nFrames) { i ->
		progress = i / nFrames.toFloat()
		rule.waitForIdle()

		// We shouldn't have remeasured or replaced Foo.
		assertWithMessage("Frame $i didn't remeasure Foo")
		.that(numberOfMeasurements)
		.isEqualTo(0)
		assertWithMessage("Frame $i didn't replace Foo").that(numberOfPlacements).isEqualTo(0)
		}
		}
		}