Fix issue where widget disappears when reordering

The issue is that if the last widget in the grid is larger than the
current widget being dragged, and we attempt to swap places with the
last widget in the grid, we will end up placing the widget outside of
the viewport. Therefore we explictly check for this case and don't swap
places. This would force the user to scroll before they can swap.

Fixes: 376493654
Test: manually on device by having a full size widget at the end of the
grid
Flag: com.android.systemui.communal_widget_resizing

Change-Id: I817a277377332fab709ef5a4c7a0216570a94f76

1 files changed, 8 insertions, 1 deletions

diff --git a/packages/SystemUI/compose/features/src/com/android/systemui/communal/ui/compose/GridDragDropState.kt b/packages/SystemUI/compose/features/src/com/android/systemui/communal/ui/compose/GridDragDropState.kt
index 1551ca97a2e3..ef5e90bd7aad 100644
--- a/packages/SystemUI/compose/features/src/com/android/systemui/communal/ui/compose/GridDragDropState.kt
+++ b/packages/SystemUI/compose/features/src/com/android/systemui/communal/ui/compose/GridDragDropState.kt
@@ -179,11 +179,18 @@ internal constructor(
         val targetItem =
             if (communalWidgetResizing()) {
                 state.layoutInfo.visibleItemsInfo.findLast { item ->
+                    val lastVisibleItemIndex = state.layoutInfo.visibleItemsInfo.last().index
                     val itemBoundingBox = IntRect(item.offset, item.size)
                     draggingItemKey != item.key &&
                         contentListState.isItemEditable(item.index) &&
                         (draggingBoundingBox.contains(itemBoundingBox.center) ||
-                            itemBoundingBox.contains(draggingBoundingBox.center))
+                            itemBoundingBox.contains(draggingBoundingBox.center)) &&
+                        // If we swap with the last visible item, and that item doesn't fit
+                        // in the gap created by moving the current item, then the current item
+                        // will get placed after the last visible item. In this case, it gets
+                        // placed outside of the viewport. We avoid this here, so the user
+                        // has to scroll first before the swap can happen.
+                        (item.index != lastVisibleItemIndex || item.span <= draggingItem.span)
                 }
             } else {
                 state.layoutInfo.visibleItemsInfo