Merge "Merge cherrypicks of ['android-review.googlesource.com/3158416'] into androidx-compose-beta-release." into androidx-compose-beta-releasesnap-temp-L55300030004920257snap-temp-L14600030004918727

3 files changed, 62 insertions, 6 deletions

diff --git a/compose/foundation/foundation/src/androidInstrumentedTest/kotlin/androidx/compose/foundation/gestures/snapping/SnapFlingBehaviorTest.kt b/compose/foundation/foundation/src/androidInstrumentedTest/kotlin/androidx/compose/foundation/gestures/snapping/SnapFlingBehaviorTest.kt
index e6d37c8ffa1..e38b01c040e 100644
--- a/compose/foundation/foundation/src/androidInstrumentedTest/kotlin/androidx/compose/foundation/gestures/snapping/SnapFlingBehaviorTest.kt
+++ b/compose/foundation/foundation/src/androidInstrumentedTest/kotlin/androidx/compose/foundation/gestures/snapping/SnapFlingBehaviorTest.kt
@@ -204,6 +204,43 @@ class SnapFlingBehaviorTest {
     }
 
     @Test
+    fun performFling_invalidOffsets_shouldNotPropagateNans_calculateSnapOffset() {
+        val testLayoutInfoProvider =
+            object : SnapLayoutInfoProvider {
+                override fun calculateSnapOffset(velocity: Float): Float = Float.NaN
+            }
+        lateinit var testFlingBehavior: TargetedFlingBehavior
+        val exception =
+            kotlin.runCatching {
+                rule.setContent {
+                    testFlingBehavior = rememberSnapFlingBehavior(testLayoutInfoProvider)
+                    VelocityEffect(testFlingBehavior, TestVelocity)
+                }
+            }
+        assert(exception.isFailure)
+    }
+
+    @Test
+    fun performFling_invalidOffsets_shouldNotPropagateNans_calculateApproachOffset() {
+        val testLayoutInfoProvider =
+            object : SnapLayoutInfoProvider {
+                override fun calculateApproachOffset(velocity: Float, decayOffset: Float): Float =
+                    Float.NaN
+
+                override fun calculateSnapOffset(velocity: Float): Float = 0.0f
+            }
+        lateinit var testFlingBehavior: TargetedFlingBehavior
+        val exception =
+            kotlin.runCatching {
+                rule.setContent {
+                    testFlingBehavior = rememberSnapFlingBehavior(testLayoutInfoProvider)
+                    VelocityEffect(testFlingBehavior, TestVelocity)
+                }
+            }
+        assert(exception.isFailure)
+    }
+
+    @Test
     fun findClosestOffset_noFlingDirection_shouldReturnAbsoluteDistance() {
         val testLayoutInfoProvider = TestLayoutInfoProvider()
         val offset = testLayoutInfoProvider.calculateSnapOffset(0f)
diff --git a/compose/foundation/foundation/src/commonMain/kotlin/androidx/compose/foundation/gestures/snapping/PagerSnapLayoutInfoProvider.kt b/compose/foundation/foundation/src/commonMain/kotlin/androidx/compose/foundation/gestures/snapping/PagerSnapLayoutInfoProvider.kt
index f33de5c766b..335eedc8769 100644
--- a/compose/foundation/foundation/src/commonMain/kotlin/androidx/compose/foundation/gestures/snapping/PagerSnapLayoutInfoProvider.kt
+++ b/compose/foundation/foundation/src/commonMain/kotlin/androidx/compose/foundation/gestures/snapping/PagerSnapLayoutInfoProvider.kt
@@ -77,6 +77,9 @@ internal fun SnapLayoutInfoProvider(
             debugLog { "Approach Velocity=$velocity" }
             val effectivePageSizePx = pagerState.pageSize + pagerState.pageSpacing
 
+            // Page Size is Zero, do not proceed.
+            if (effectivePageSizePx == 0) return 0f
+
             // given this velocity, where can I go with a decay animation.
             val animationOffsetPx = decayOffset
 
@@ -246,8 +249,13 @@ internal fun calculateFinalSnappingBound(
             "layoutDirection=$layoutDirection"
     }
     // how many pages have I scrolled using a drag gesture.
+    val pageSize = pagerState.layoutInfo.pageSize
     val offsetFromSnappedPosition =
-        pagerState.dragGestureDelta() / pagerState.layoutInfo.pageSize.toFloat()
+        if (pageSize == 0) {
+            0f
+        } else {
+            pagerState.dragGestureDelta() / pageSize.toFloat()
+        }
 
     // we're only interested in the decimal part of the offset.
     val offsetFromSnappedPositionOverflow =
diff --git a/compose/foundation/foundation/src/commonMain/kotlin/androidx/compose/foundation/gestures/snapping/SnapFlingBehavior.kt b/compose/foundation/foundation/src/commonMain/kotlin/androidx/compose/foundation/gestures/snapping/SnapFlingBehavior.kt
index d4134b62c7b..3956b6f9cad 100644
--- a/compose/foundation/foundation/src/commonMain/kotlin/androidx/compose/foundation/gestures/snapping/SnapFlingBehavior.kt
+++ b/compose/foundation/foundation/src/commonMain/kotlin/androidx/compose/foundation/gestures/snapping/SnapFlingBehavior.kt
@@ -127,10 +127,15 @@ class SnapFlingBehavior(
                     initialValue = 0.0f
                 )
 
-            val initialOffset =
-                snapLayoutInfoProvider.calculateApproachOffset(initialVelocity, decayOffset)
-            var remainingScrollOffset =
-                abs(initialOffset) * sign(initialVelocity) // ensure offset sign is correct
+                val initialOffset =
+                    snapLayoutInfoProvider.calculateApproachOffset(initialVelocity, decayOffset)
+
+                check(!initialOffset.isNaN()) {
+                    "calculateApproachOffset returned NaN. Please use a valid value."
+                }
+
+                // ensure offset sign and value are correct
+                var remainingScrollOffset = abs(initialOffset) * sign(initialVelocity)
 
             onRemainingScrollOffsetUpdate(remainingScrollOffset) // First Scroll Offset
 
@@ -142,9 +147,15 @@ class SnapFlingBehavior(
                 onRemainingScrollOffsetUpdate(remainingScrollOffset)
             }
 
-            remainingScrollOffset =
+            val finalSnapOffset =
                 snapLayoutInfoProvider.calculateSnapOffset(animationState.velocity)
 
+            check(!finalSnapOffset.isNaN()) {
+                "calculateSnapOffset returned NaN. Please use a valid value."
+            }
+
+            remainingScrollOffset = finalSnapOffset
+
             debugLog { "Settling Final Bound=$remainingScrollOffset" }
 
             animateWithTarget(