Merge "STL SwipeAnimation progress bounded between 0 and 1" into main

2 files changed, 66 insertions, 37 deletions

diff --git a/packages/SystemUI/compose/scene/src/com/android/compose/animation/scene/SwipeAnimation.kt b/packages/SystemUI/compose/scene/src/com/android/compose/animation/scene/SwipeAnimation.kt
index 607e4fadc256..ba92f9bea07d 100644
--- a/packages/SystemUI/compose/scene/src/com/android/compose/animation/scene/SwipeAnimation.kt
+++ b/packages/SystemUI/compose/scene/src/com/android/compose/animation/scene/SwipeAnimation.kt
@@ -315,16 +315,10 @@ internal class SwipeAnimation<T : ContentKey>(
         val skipAnimation =
             hasReachedTargetContent && !contentTransition.isWithinProgressRange(initialProgress)
 
-        val targetOffset =
-            if (targetContent == fromContent) {
-                0f
-            } else {
-                val distance = distance()
-                check(distance != DistanceUnspecified) {
-                    "distance is equal to $DistanceUnspecified"
-                }
-                distance
-            }
+        val distance = distance()
+        check(distance != DistanceUnspecified) { "distance is equal to $DistanceUnspecified" }
+
+        val targetOffset = if (targetContent == fromContent) 0f else distance
 
         // If the effective current content changed, it should be reflected right now in the
         // current state, even before the settle animation is ongoing. That way all the
@@ -343,7 +337,16 @@ internal class SwipeAnimation<T : ContentKey>(
             }
 
         val animatable =
-            Animatable(initialOffset, OffsetVisibilityThreshold).also { offsetAnimation = it }
+            Animatable(initialOffset, OffsetVisibilityThreshold).also {
+                offsetAnimation = it
+
+                // We should animate when the progress value is between [0, 1].
+                if (distance > 0) {
+                    it.updateBounds(0f, distance)
+                } else {
+                    it.updateBounds(distance, 0f)
+                }
+            }
 
         check(isAnimatingOffset())
 
@@ -370,42 +373,26 @@ internal class SwipeAnimation<T : ContentKey>(
         val velocityConsumed = CompletableDeferred<Float>()
 
         offsetAnimationRunnable.complete {
-            try {
+            val result =
                 animatable.animateTo(
                     targetValue = targetOffset,
                     animationSpec = swipeSpec,
                     initialVelocity = initialVelocity,
-                ) {
-                    // Immediately stop this transition if we are bouncing on a content that
-                    // does not bounce.
-                    if (!contentTransition.isWithinProgressRange(progress)) {
-                        // We are no longer able to consume the velocity, the rest can be
-                        // consumed by another component in the hierarchy.
-                        velocityConsumed.complete(initialVelocity - velocity)
-                        throw SnapException()
-                    }
-                }
-            } catch (_: SnapException) {
-                /* Ignore. */
-            } finally {
-                if (!velocityConsumed.isCompleted) {
-                    // The animation consumed the whole available velocity
-                    velocityConsumed.complete(initialVelocity)
-                }
+                )
 
-                // Wait for overscroll to finish so that the transition is removed from the STLState
-                // only after the overscroll is done, to avoid dropping frame right when the user
-                // lifts their finger and overscroll is animated to 0.
-                overscrollCompletable?.await()
-            }
+            // We are no longer able to consume the velocity, the rest can be consumed by another
+            // component in the hierarchy.
+            velocityConsumed.complete(initialVelocity - result.endState.velocity)
+
+            // Wait for overscroll to finish so that the transition is removed from the STLState
+            // only after the overscroll is done, to avoid dropping frame right when the user
+            // lifts their finger and overscroll is animated to 0.
+            overscrollCompletable?.await()
         }
 
         return velocityConsumed.await()
     }
 
-    /** An exception thrown during the animation to stop it immediately. */
-    private class SnapException : Exception()
-
     private fun canChangeContent(targetContent: ContentKey): Boolean {
         return when (val transition = contentTransition) {
             is TransitionState.Transition.ChangeScene ->
diff --git a/packages/SystemUI/compose/scene/tests/src/com/android/compose/animation/scene/SceneTransitionLayoutTest.kt b/packages/SystemUI/compose/scene/tests/src/com/android/compose/animation/scene/SceneTransitionLayoutTest.kt
index 7c8c6e5f6c12..e580e3c40690 100644
--- a/packages/SystemUI/compose/scene/tests/src/com/android/compose/animation/scene/SceneTransitionLayoutTest.kt
+++ b/packages/SystemUI/compose/scene/tests/src/com/android/compose/animation/scene/SceneTransitionLayoutTest.kt
@@ -21,6 +21,7 @@ import androidx.compose.animation.core.LinearEasing
 import androidx.compose.animation.core.tween
 import androidx.compose.foundation.background
 import androidx.compose.foundation.layout.Box
+import androidx.compose.foundation.layout.Spacer
 import androidx.compose.foundation.layout.fillMaxSize
 import androidx.compose.foundation.layout.offset
 import androidx.compose.foundation.layout.size
@@ -33,6 +34,7 @@ import androidx.compose.runtime.setValue
 import androidx.compose.ui.Alignment
 import androidx.compose.ui.Modifier
 import androidx.compose.ui.graphics.Color
+import androidx.compose.ui.platform.LocalViewConfiguration
 import androidx.compose.ui.platform.testTag
 import androidx.compose.ui.test.SemanticsNodeInteraction
 import androidx.compose.ui.test.assertHeightIsEqualTo
@@ -43,6 +45,9 @@ import androidx.compose.ui.test.junit4.createComposeRule
 import androidx.compose.ui.test.onChild
 import androidx.compose.ui.test.onNodeWithTag
 import androidx.compose.ui.test.onNodeWithText
+import androidx.compose.ui.test.onRoot
+import androidx.compose.ui.test.performTouchInput
+import androidx.compose.ui.test.swipeDown
 import androidx.compose.ui.unit.Dp
 import androidx.compose.ui.unit.DpOffset
 import androidx.compose.ui.unit.IntOffset
@@ -469,4 +474,41 @@ class SceneTransitionLayoutTest {
 
         assertThat(layoutImpl.overlaysOrNullForTest()).isNull()
     }
+
+    @Test
+    fun transitionProgressBoundedBetween0And1() {
+        val layoutWidth = 200.dp
+        val layoutHeight = 400.dp
+
+        // The draggable touch slop, i.e. the min px distance a touch pointer must move before it is
+        // detected as a drag event.
+        var touchSlop = 0f
+        val state = rule.runOnUiThread { MutableSceneTransitionLayoutState(initialScene = SceneA) }
+        rule.setContent {
+            touchSlop = LocalViewConfiguration.current.touchSlop
+            SceneTransitionLayout(state, Modifier.size(layoutWidth, layoutHeight)) {
+                scene(SceneA, userActions = mapOf(Swipe.Down to SceneB)) {
+                    Spacer(Modifier.fillMaxSize())
+                }
+                scene(SceneB) { Spacer(Modifier.fillMaxSize()) }
+            }
+        }
+        assertThat(state.transitionState).isIdle()
+
+        rule.mainClock.autoAdvance = false
+
+        // Swipe the verticalSwipeDistance.
+        rule.onRoot().performTouchInput {
+            swipeDown(endY = bottom + touchSlop, durationMillis = 50)
+        }
+
+        rule.mainClock.advanceTimeBy(16)
+        val transition = assertThat(state.transitionState).isSceneTransition()
+        assertThat(transition).isNotNull()
+        assertThat(transition).hasProgress(1f, tolerance = 0.01f)
+
+        rule.mainClock.advanceTimeBy(16)
+        // Fling animation, we are overscrolling now. Progress should always be between [0, 1].
+        assertThat(transition).hasProgress(1f)
+    }
 }