Merge "Don't interpolate the STL size when overscrolling" into main

2 files changed, 46 insertions, 1 deletions

diff --git a/packages/SystemUI/compose/scene/src/com/android/compose/animation/scene/SceneTransitionLayoutImpl.kt b/packages/SystemUI/compose/scene/src/com/android/compose/animation/scene/SceneTransitionLayoutImpl.kt
index f32720c4716d..7ea8cbdd7a97 100644
--- a/packages/SystemUI/compose/scene/src/com/android/compose/animation/scene/SceneTransitionLayoutImpl.kt
+++ b/packages/SystemUI/compose/scene/src/com/android/compose/animation/scene/SceneTransitionLayoutImpl.kt
@@ -293,7 +293,15 @@ private class LayoutNode(var layoutImpl: SceneTransitionLayoutImpl) :
                 width = fromSize.width
                 height = fromSize.height
             } else {
-                val size = lerp(fromSize, toSize, transition.progress)
+                val overscrollSpec = transition.currentOverscrollSpec
+                val progress =
+                    when {
+                        overscrollSpec == null -> transition.progress
+                        overscrollSpec.scene == transition.toScene -> 1f
+                        else -> 0f
+                    }
+
+                val size = lerp(fromSize, toSize, progress)
                 width = size.width.coerceAtLeast(0)
                 height = size.height.coerceAtLeast(0)
             }
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 08532bd72e33..a8dd572c4d50 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.FastOutSlowInEasing
 import androidx.compose.animation.core.LinearEasing
 import androidx.compose.animation.core.tween
 import androidx.compose.foundation.background
+import androidx.compose.foundation.gestures.Orientation
 import androidx.compose.foundation.layout.Box
 import androidx.compose.foundation.layout.fillMaxSize
 import androidx.compose.foundation.layout.offset
@@ -333,6 +334,42 @@ class SceneTransitionLayoutTest {
     }
 
     @Test
+    fun layoutSizeDoesNotOverscrollWhenOverscrollIsSpecified() {
+        val state =
+            rule.runOnUiThread {
+                MutableSceneTransitionLayoutStateImpl(
+                    SceneA,
+                    transitions { overscroll(SceneB, Orientation.Horizontal) }
+                )
+            }
+
+        val layoutTag = "layout"
+        rule.setContent {
+            SceneTransitionLayout(state, Modifier.testTag(layoutTag)) {
+                scene(SceneA) { Box(Modifier.size(50.dp)) }
+                scene(SceneB) { Box(Modifier.size(70.dp)) }
+            }
+        }
+
+        // Overscroll on A at -100%: size should be interpolated given that there is no overscroll
+        // defined for scene A.
+        var progress by mutableStateOf(-1f)
+        rule.runOnIdle {
+            state.startTransition(transition(from = SceneA, to = SceneB, progress = { progress }))
+        }
+        rule.onNodeWithTag(layoutTag).assertSizeIsEqualTo(30.dp)
+
+        // Middle of the transition.
+        progress = 0.5f
+        rule.onNodeWithTag(layoutTag).assertSizeIsEqualTo(60.dp)
+
+        // Overscroll on B at 200%: size should not be interpolated given that there is an
+        // overscroll defined for scene B.
+        progress = 2f
+        rule.onNodeWithTag(layoutTag).assertSizeIsEqualTo(70.dp)
+    }
+
+    @Test
     fun multipleTransitionsWillComposeMultipleScenes() {
         val duration = 10 * 16L