Fix crash with Rotary input and empty visible items (#1848)

Bug: b/305901991
google · Dec 4, 2023 · 1dcdf49 · 1dcdf49
1 parent 1d915f7
commit 1dcdf49
Show file tree

Hide file tree

Showing 2 changed files with 37 additions and 2 deletions.
diff --git a/...c/main/java/com/google/android/horologist/composables/picker/PickerRotaryScrollAdapter.kt b/...c/main/java/com/google/android/horologist/composables/picker/PickerRotaryScrollAdapter.kt
@@ -42,7 +42,7 @@ internal class PickerRotaryScrollAdapter(
      */
     override fun averageItemSize(): Float =
         scrollableState.scalingLazyListState
-            .layoutInfo.visibleItemsInfo.first().unadjustedSize.toFloat()
+            .layoutInfo.visibleItemsInfo.firstOrNull()?.unadjustedSize?.toFloat() ?: 0f
 
     /**
      * Current (centred) item index
@@ -81,7 +81,7 @@ internal class AndroidxPickerRotaryScrollAdapter(
      */
     override fun averageItemSize(): Float =
         scrollableState.scalingLazyListState
-            .layoutInfo.visibleItemsInfo.first().unadjustedSize.toFloat()
+            .layoutInfo.visibleItemsInfo.firstOrNull()?.unadjustedSize?.toFloat() ?: 0f
 
     /**
      * Current (centred) item index

diff --git a/...sables/src/test/kotlin/com/google/android/horologist/composables/RotaryInteractionTest.kt b/...sables/src/test/kotlin/com/google/android/horologist/composables/RotaryInteractionTest.kt
@@ -18,6 +18,7 @@ package com.google.android.horologist.composables
 
 import androidx.compose.foundation.layout.height
 import androidx.compose.runtime.Composable
+import androidx.compose.runtime.rememberCoroutineScope
 import androidx.compose.ui.Modifier
 import androidx.compose.ui.focus.FocusRequester
 import androidx.compose.ui.focus.focusRequester
@@ -34,6 +35,9 @@ import com.google.android.horologist.composables.picker.PickerScope
 import com.google.android.horologist.composables.picker.PickerState
 import com.google.android.horologist.composables.picker.rememberPickerState
 import com.google.common.truth.Truth.assertThat
+import kotlinx.coroutines.CoroutineScope
+import kotlinx.coroutines.async
+import kotlinx.coroutines.launch
 import org.junit.Rule
 import org.junit.Test
 import org.junit.runner.RunWith
@@ -165,6 +169,37 @@ class RotaryInteractionTest {
         }
     }
 
+    @OptIn(ExperimentalTestApi::class)
+    @Test
+    fun scrollPicker_receiveRotaryEventsBeforeInitialisation() {
+        lateinit var pickerState: PickerState
+        val selectedOption = 5
+        val numberOfOptions = 15
+        lateinit var scope: CoroutineScope
+
+        // Disable clock so that we'll be able to send events before composition finishes
+        rule.mainClock.autoAdvance = false
+
+        rule.setContent {
+            pickerState = rememberPickerState(
+                initialNumberOfOptions = numberOfOptions,
+                initiallySelectedOption = selectedOption,
+                repeatItems = true,
+            )
+            defaultPickerWithRotaryAccumulator(pickerState)
+            scope = rememberCoroutineScope()
+        }
+
+        scope.launch {
+            focusRequester.requestFocus()
+            async {
+                rule.onNodeWithTag(TEST_TAG).performRotaryScrollInput {
+                    rotateToScrollVertically(50.0f)
+                }
+            }
+        }
+    }
+
     @Composable
     private fun pickerOption(): (@Composable PickerScope.(optionIndex: Int, pickerSelected: Boolean) -> Unit) =
         { value: Int, pickerSelected: Boolean ->