Fix race condition in LockscreenSceneTransitionInteractor

LockscreenSceneTransitionInteractor did rely on sharedFlows which might
be not up-to-date and therefore caused a race condition. With the recent
addition of currentTransitionInfoInternal we are able to get the most
recent transition info.

Test: Ignored unit test now working
Test: Manual test of the scenario in the bug
Bug: b/340616271
Flag: ACONFIG com.android.systemui.scene_container DEVELOPMENT
Change-Id: I435036354ec76f68600c72acee280e5f14d695bb

3 files changed, 7 insertions, 5 deletions

diff --git a/packages/SystemUI/src/com/android/systemui/keyguard/domain/interactor/KeyguardTransitionInteractor.kt b/packages/SystemUI/src/com/android/systemui/keyguard/domain/interactor/KeyguardTransitionInteractor.kt
index 30c6718adf1b..8f9a709801ae 100644
--- a/packages/SystemUI/src/com/android/systemui/keyguard/domain/interactor/KeyguardTransitionInteractor.kt
+++ b/packages/SystemUI/src/com/android/systemui/keyguard/domain/interactor/KeyguardTransitionInteractor.kt
@@ -218,6 +218,8 @@ constructor(
             .map { step -> step.to }
             .shareIn(scope, SharingStarted.Eagerly, replay = 1)
 
+    val currentTransitionInfo: StateFlow<TransitionInfo> = repository.currentTransitionInfoInternal
+
     /** The from state of the last [TransitionState.STARTED] transition. */
     // TODO: is it performant to have several SharedFlows side by side instead of one?
     @SuppressLint("SharedFlowCreation")
diff --git a/packages/SystemUI/src/com/android/systemui/keyguard/domain/interactor/scenetransition/LockscreenSceneTransitionInteractor.kt b/packages/SystemUI/src/com/android/systemui/keyguard/domain/interactor/scenetransition/LockscreenSceneTransitionInteractor.kt
index 6e00aa7956e7..3baeb7682e12 100644
--- a/packages/SystemUI/src/com/android/systemui/keyguard/domain/interactor/scenetransition/LockscreenSceneTransitionInteractor.kt
+++ b/packages/SystemUI/src/com/android/systemui/keyguard/domain/interactor/scenetransition/LockscreenSceneTransitionInteractor.kt
@@ -131,7 +131,7 @@ constructor(
         val newTransition =
             TransitionInfo(
                 ownerName = this::class.java.simpleName,
-                from = transitionInteractor.getStartedState(),
+                from = transitionInteractor.currentTransitionInfo.value.to,
                 to = state,
                 animator = null,
                 modeOnCanceled = TransitionModeOnCanceled.REVERSE
@@ -150,7 +150,7 @@ constructor(
     private suspend fun handleTransition(transition: ObservableTransitionState.Transition) {
         if (transition.fromScene == Scenes.Lockscreen) {
             if (currentTransitionId != null) {
-                val currentToState = transitionInteractor.getStartedState()
+                val currentToState = transitionInteractor.currentTransitionInfo.value.to
                 if (currentToState == UNDEFINED) {
                     transitionKtfTo(transitionInteractor.getStartedFromState())
                 }
@@ -169,6 +169,8 @@ constructor(
     }
 
     private suspend fun transitionKtfTo(state: KeyguardState) {
+        // TODO(b/330311871): This is based on a sharedFlow and thus might not be up-to-date and
+        //  cause a race condition. (There is no known scenario that is currently affected.)
         val currentTransition = transitionInteractor.transitionState.value
         if (currentTransition.isFinishedIn(state)) {
             // This is already the state we want to be in
@@ -199,7 +201,7 @@ constructor(
     }
 
     private suspend fun startTransitionFromLockscreen() {
-        val currentState = transitionInteractor.getStartedState()
+        val currentState = transitionInteractor.currentTransitionInfo.value.to
         val newTransition =
             TransitionInfo(
                 ownerName = this::class.java.simpleName,
diff --git a/packages/SystemUI/tests/src/com/android/systemui/keyguard/domain/interactor/scenetransition/LockscreenSceneTransitionInteractorTest.kt b/packages/SystemUI/tests/src/com/android/systemui/keyguard/domain/interactor/scenetransition/LockscreenSceneTransitionInteractorTest.kt
index d0d9891a953f..8a5af09f52ed 100644
--- a/packages/SystemUI/tests/src/com/android/systemui/keyguard/domain/interactor/scenetransition/LockscreenSceneTransitionInteractorTest.kt
+++ b/packages/SystemUI/tests/src/com/android/systemui/keyguard/domain/interactor/scenetransition/LockscreenSceneTransitionInteractorTest.kt
@@ -40,7 +40,6 @@ import kotlinx.coroutines.flow.flowOf
 import kotlinx.coroutines.launch
 import kotlinx.coroutines.test.runTest
 import org.junit.Before
-import org.junit.Ignore
 import org.junit.runner.RunWith
 
 @SmallTest
@@ -1149,7 +1148,6 @@ class LockscreenSceneTransitionInteractorTest : SysuiTestCase() {
      *
      * In STL there is no guarantee that transitions settle in Idle before continuing.
      */
-    @Ignore("Suffers from a race condition that will be fixed in followup CL")
     @Test
     fun transition_from_ls_scene_interrupted_by_other_from_ls_transition() =
         testScope.runTest {