Merge "Expose ElementKey.currentAlpha() in ContentScope" into main (96f6c51e) · Commits · e / os / android_frameworks_base

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

+2 −2

Original line number	Original line	Diff line number	Diff line
	@@ -692,7 +692,7 @@ internal class ElementNode(
	}		}

	/** The [TransitionState] that we should consider for [element]. */		/** The [TransitionState] that we should consider for [element]. */
	private fun elementState(		internal fun elementState(
	layoutImpl: SceneTransitionLayoutImpl,		layoutImpl: SceneTransitionLayoutImpl,
	element: Element,		element: Element,
	transitionStates: List<List<TransitionState>>,		transitionStates: List<List<TransitionState>>,
	@@ -1127,7 +1127,7 @@ private fun isElementOpaque(
	* [isElementOpaque] is checked during placement and we don't want to read the transition progress		* [isElementOpaque] is checked during placement and we don't want to read the transition progress
	* in that phase.		* in that phase.
	*/		*/
	private fun elementAlpha(		internal fun elementAlpha(
	layoutImpl: SceneTransitionLayoutImpl,		layoutImpl: SceneTransitionLayoutImpl,
	element: Element,		element: Element,
	transition: TransitionState.Transition?,		transition: TransitionState.Transition?,

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

+9 −0

Original line number	Original line	Diff line number	Diff line
	@@ -312,6 +312,15 @@ interface BaseContentScope : ElementStateScope {
	fun Modifier.disableSwipesWhenScrolling(		fun Modifier.disableSwipesWhenScrolling(
	bounds: NestedScrollableBound = NestedScrollableBound.Any		bounds: NestedScrollableBound = NestedScrollableBound.Any
	): Modifier		): Modifier

			/**
			* Return the alpha of [this] element in this content, given the current transition state and
			* transition transformations (e.g. fade).
			*
			* Important: This should not be read during composition and should instead be read during
			* layout, drawing or in a LaunchedEffect.
			*/
			fun ElementKey.currentAlpha(): Float?
	}		}

	@Stable		@Stable

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

+14 −0

Original line number	Original line	Diff line number	Diff line
	@@ -76,8 +76,12 @@ import com.android.compose.animation.scene.UserAction
	import com.android.compose.animation.scene.UserActionResult		import com.android.compose.animation.scene.UserActionResult
	import com.android.compose.animation.scene.ValueKey		import com.android.compose.animation.scene.ValueKey
	import com.android.compose.animation.scene.animateSharedValueAsState		import com.android.compose.animation.scene.animateSharedValueAsState
			import com.android.compose.animation.scene.content.state.TransitionState
	import com.android.compose.animation.scene.effect.GestureEffect		import com.android.compose.animation.scene.effect.GestureEffect
	import com.android.compose.animation.scene.element		import com.android.compose.animation.scene.element
			import com.android.compose.animation.scene.elementAlpha
			import com.android.compose.animation.scene.elementState
			import com.android.compose.animation.scene.getAllNestedTransitionStates
	import com.android.compose.animation.scene.modifiers.noResizeDuringTransitions		import com.android.compose.animation.scene.modifiers.noResizeDuringTransitions
	import com.android.compose.gesture.NestedScrollControlState		import com.android.compose.gesture.NestedScrollControlState
	import com.android.compose.gesture.NestedScrollableBound		import com.android.compose.gesture.NestedScrollableBound
	@@ -422,6 +426,16 @@ internal class ContentScopeImpl(
	it.fromContent == content \|\| it.toContent == content		it.fromContent == content \|\| it.toContent == content
	}		}
	}		}

			override fun ElementKey.currentAlpha(): Float? {
			val element = layoutImpl.elements[this] ?: return null
			val stateInContent = element.stateByContent[contentKey] ?: return null
			val elementState =
			elementState(layoutImpl, element, getAllNestedTransitionStates(layoutImpl))
			?: return null
			val transition = elementState as? TransitionState.Transition
			return elementAlpha(layoutImpl, element, transition, stateInContent)
			}
	}		}

	/** A [LifecycleOwner] that follows its [parentLifecycle] but is capped at [maxLifecycleState]. */		/** A [LifecycleOwner] that follows its [parentLifecycle] but is capped at [maxLifecycleState]. */

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

+53 −0

Original line number	Original line	Diff line number	Diff line
	@@ -24,11 +24,13 @@ import androidx.compose.foundation.layout.fillMaxSize
	import androidx.compose.runtime.Composable		import androidx.compose.runtime.Composable
	import androidx.compose.runtime.CompositionLocalProvider		import androidx.compose.runtime.CompositionLocalProvider
	import androidx.compose.runtime.DisposableEffect		import androidx.compose.runtime.DisposableEffect
			import androidx.compose.runtime.LaunchedEffect
	import androidx.compose.runtime.SideEffect		import androidx.compose.runtime.SideEffect
	import androidx.compose.runtime.getValue		import androidx.compose.runtime.getValue
	import androidx.compose.runtime.mutableStateOf		import androidx.compose.runtime.mutableStateOf
	import androidx.compose.runtime.remember		import androidx.compose.runtime.remember
	import androidx.compose.runtime.setValue		import androidx.compose.runtime.setValue
			import androidx.compose.runtime.snapshotFlow
	import androidx.compose.ui.Modifier		import androidx.compose.ui.Modifier
	import androidx.compose.ui.geometry.Offset		import androidx.compose.ui.geometry.Offset
	import androidx.compose.ui.platform.LocalViewConfiguration		import androidx.compose.ui.platform.LocalViewConfiguration
	@@ -380,4 +382,55 @@ class ContentTest {
	assertThat(nestedMiddle.ancestors).containsExactly(outerState)		assertThat(nestedMiddle.ancestors).containsExactly(outerState)
	assertThat(nestedInner.ancestors).containsExactly(outerState, middleState).inOrder()		assertThat(nestedInner.ancestors).containsExactly(outerState, middleState).inOrder()
	}		}

			@Test
			fun currentElementAlpha() {
			var lastAlpha: Float? = null

			val state =
			rule.runOnUiThread {
			MutableSceneTransitionLayoutStateForTests(
			SceneA,
			transitions =
			transitions { from(SceneA, to = SceneB) { fade(TestElements.Foo) } },
			)
			}
			val scope =
			rule.setContentAndCreateMainScope {
			SceneTransitionLayout(state) {
			scene(SceneA) {}
			scene(SceneB) {
			LaunchedEffect(Unit) {
			snapshotFlow { TestElements.Foo.currentAlpha() }
			.collect { lastAlpha = it }
			}

			Box(Modifier.element(TestElements.Foo).fillMaxSize())
			}
			}
			}

			assertThat(lastAlpha).isNull()

			var progress by mutableStateOf(0f)
			scope.launch { state.startTransition(transition(SceneA, SceneB, progress = { progress })) }
			rule.waitForIdle()
			assertThat(lastAlpha).isWithin(0.01f).of(0f)

			progress = 0.25f
			rule.waitForIdle()
			assertThat(lastAlpha).isWithin(0.01f).of(0.25f)

			progress = 0.5f
			rule.waitForIdle()
			assertThat(lastAlpha).isWithin(0.01f).of(0.5f)

			progress = 0.75f
			rule.waitForIdle()
			assertThat(lastAlpha).isWithin(0.01f).of(0.75f)

			progress = 1f
			rule.waitForIdle()
			assertThat(lastAlpha).isWithin(0.01f).of(1f)
			}
	}		}