Scroll partially offscreen items to be fully onscreen when toggled

Test: manual test using ShareTest
BUG: 351883537
FIX: 351883537
Flag: com.android.intentresolver.shareousel_scroll_offscreen_selections
Change-Id: Id9c7e31169bce11b722868338f87228c9450c9aa

2 files changed, 47 insertions, 0 deletions

diff --git a/aconfig/FeatureFlags.aconfig b/aconfig/FeatureFlags.aconfig
index 6f7e75d5..8396bc24 100644
--- a/aconfig/FeatureFlags.aconfig
+++ b/aconfig/FeatureFlags.aconfig
@@ -116,3 +116,10 @@ flag {
   description: "Allow toggling of final Shareousel item"
   bug: "349468879"
 }
+
+flag {
+  name: "shareousel_scroll_offscreen_selections"
+  namespace: "intentresolver"
+  description: "Whether to scroll items onscreen when they are partially offscreen and selected/unselected."
+  bug: "351883537"
+}
diff --git a/java/src/com/android/intentresolver/contentpreview/payloadtoggle/ui/composable/ShareouselComposable.kt b/java/src/com/android/intentresolver/contentpreview/payloadtoggle/ui/composable/ShareouselComposable.kt
index f8cf243d..4b87d227 100644
--- a/java/src/com/android/intentresolver/contentpreview/payloadtoggle/ui/composable/ShareouselComposable.kt
+++ b/java/src/com/android/intentresolver/contentpreview/payloadtoggle/ui/composable/ShareouselComposable.kt
@@ -64,6 +64,7 @@ import androidx.compose.ui.semantics.contentDescription
 import androidx.compose.ui.semantics.semantics
 import androidx.compose.ui.unit.dp
 import androidx.lifecycle.compose.collectAsStateWithLifecycle
+import com.android.intentresolver.Flags.shareouselScrollOffscreenSelections
 import com.android.intentresolver.Flags.unselectFinalItem
 import com.android.intentresolver.R
 import com.android.intentresolver.contentpreview.payloadtoggle.domain.model.ValueUpdate
@@ -189,6 +190,45 @@ private fun PreviewCarousel(
                     firstSelectedIndex = min(index, firstSelectedIndex ?: Int.MAX_VALUE)
                 }
 
+                if (shareouselScrollOffscreenSelections()) {
+                    LaunchedEffect(index, model.uri) {
+                        var current: Boolean? = null
+                        previewModel.isSelected.collect { selected ->
+                            when {
+                                // First update will always be the current state, so we just want to
+                                // record the state and do nothing else.
+                                current == null -> current = selected
+
+                                // We only want to act when the state changes
+                                current != selected -> {
+                                    current = selected
+                                    with(carouselState.layoutInfo) {
+                                        visibleItemsInfo
+                                            .firstOrNull { it.index == index }
+                                            ?.let { item ->
+                                                when {
+                                                    // Item is partially past start of viewport
+                                                    item.offset < viewportStartOffset ->
+                                                        -viewportStartOffset
+                                                    // Item is partially past end of viewport
+                                                    (item.offset + item.size) > viewportEndOffset ->
+                                                        item.size - viewportEndOffset
+                                                    // Item is fully within viewport
+                                                    else -> null
+                                                }?.let { scrollOffset ->
+                                                    carouselState.animateScrollToItem(
+                                                        index = index,
+                                                        scrollOffset = scrollOffset,
+                                                    )
+                                                }
+                                            }
+                                    }
+                                }
+                            }
+                        }
+                    }
+                }
+
                 ShareouselCard(
                     viewModel.preview(
                         model,