[GridNG] Consider subgridded items in parent grid sizing

Bug: 618969
Change-Id: I6422f12b04d9041219c0e127f75e336ff7b4caee
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/3553429
Reviewed-by: Ian Kilpatrick <ikilpatrick@chromium.org>
Commit-Queue: Ethan Jimenez <ethavar@microsoft.com>
Cr-Commit-Position: refs/heads/main@{#987076}

third_party/blink/renderer/core/layout/ng/grid/layout_ng_grid.cc

@@ -161,18 +161,25 @@ wtf_size_t LayoutNGGrid::ExplicitGridStartForDirection(
 wtf_size_t LayoutNGGrid::ExplicitGridEndForDirection(
     const GridTrackSizingDirection track_direction) const {
   NOT_DESTROYED();
-  const wtf_size_t start_offset =
-      ExplicitGridStartForDirection(track_direction);
+  if (IsGridPlacementDirty())
+    return 0;
+
+  const bool is_for_columns = track_direction == kForColumns;
+  const wtf_size_t subgrid_span_size =
+      is_for_columns ? cached_placement_data_.column_subgrid_span_size
+                     : cached_placement_data_.row_subgrid_span_size;
+
+  const wtf_size_t explicit_grid_track_count =
+      is_for_columns ? GridPositionsResolver::ExplicitGridColumnCount(
+                           StyleRef(), AutoRepeatCountForDirection(kForColumns),
+                           /* is_ng_grid */ true, subgrid_span_size)
+                     : GridPositionsResolver::ExplicitGridRowCount(
+                           StyleRef(), AutoRepeatCountForDirection(kForRows),
+                           /* is_ng_grid */ true, subgrid_span_size);
 
   return base::checked_cast<wtf_size_t>(
-      start_offset +
-      ((track_direction == kForColumns)
-           ? GridPositionsResolver::ExplicitGridColumnCount(
-                 StyleRef(), AutoRepeatCountForDirection(kForColumns),
-                 /* is_ng_grid */ true)
-           : GridPositionsResolver::ExplicitGridRowCount(
-                 StyleRef(), AutoRepeatCountForDirection(kForRows),
-                 /* is_ng_grid */ true)));
+      ExplicitGridStartForDirection(track_direction) +
+      explicit_grid_track_count);
 }
 
 LayoutUnit LayoutNGGrid::GridGap(

third_party/blink/renderer/core/layout/ng/grid/ng_grid_data.h

@@ -28,6 +28,21 @@ struct CORE_EXPORT NGGridPlacementData {
            row_start_offset == other.row_start_offset;
   }
 
+  bool HasStandalonePlacement(GridTrackSizingDirection track_direction) const {
+    const wtf_size_t subgrid_span_size = (track_direction == kForColumns)
+                                             ? column_subgrid_span_size
+                                             : row_subgrid_span_size;
+    return subgrid_span_size == kNotFound;
+  }
+
+  void SetSubgridSpanSize(wtf_size_t subgrid_span_size,
+                          GridTrackSizingDirection track_direction) {
+    if (track_direction == kForColumns)
+      column_subgrid_span_size = subgrid_span_size;
+    else
+      row_subgrid_span_size = subgrid_span_size;
+  }
+
   Vector<GridArea> grid_item_positions;
 
   bool is_parent_grid_container : 1;
@@ -50,6 +65,10 @@ struct CORE_EXPORT NGGridLayoutData {
  public:
   NGGridLayoutData() = default;
 
+  NGGridLayoutData(std::unique_ptr<NGGridLayoutTrackCollection> columns,
+                   std::unique_ptr<NGGridLayoutTrackCollection> rows)
+      : columns(std::move(columns)), rows(std::move(rows)) {}
+
   NGGridLayoutData(const NGGridLayoutData& other) { CopyFrom(other); }
 
   NGGridLayoutData& operator=(const NGGridLayoutData& other) {
@@ -65,12 +84,12 @@ struct CORE_EXPORT NGGridLayoutData {
   }
 
   NGGridLayoutTrackCollection* Columns() const {
-    DCHECK(columns);
+    DCHECK(columns && columns->Direction() == kForColumns);
     return columns.get();
   }
 
   NGGridLayoutTrackCollection* Rows() const {
-    DCHECK(rows);
+    DCHECK(rows && rows->Direction() == kForRows);
     return rows.get();
   }
 

third_party/blink/renderer/core/layout/ng/grid/ng_grid_item.cc

@@ -160,7 +160,9 @@ BaselineType DetermineBaselineType(
 GridItemData::GridItemData(const NGBlockNode node,
                            const ComputedStyle& container_style,
                            const WritingMode container_writing_mode)
-    : node(node), is_sizing_dependent_on_block_size(false) {
+    : node(node),
+      is_sizing_dependent_on_block_size(false),
+      is_subgridded_to_parent_grid(false) {
   const auto& style = node.Style();
 
   const bool is_replaced = node.IsReplaced();
@@ -269,7 +271,7 @@ void GridItemData::ComputeSetIndices(
     DCHECK_EQ(computed_range_index, range_indices.begin);
 
     computed_range_index =
-        track_collection.RangeIndexFromGridLine(EndLine(track_direction)) - 1;
+        track_collection.RangeIndexFromGridLine(EndLine(track_direction) - 1);
     DCHECK_EQ(computed_range_index, range_indices.end);
   }
 #endif
@@ -280,7 +282,7 @@ void GridItemData::ComputeSetIndices(
     range_indices.begin =
         track_collection.RangeIndexFromGridLine(StartLine(track_direction));
     range_indices.end =
-        track_collection.RangeIndexFromGridLine(EndLine(track_direction)) - 1;
+        track_collection.RangeIndexFromGridLine(EndLine(track_direction) - 1);
   }
 
   DCHECK_LT(range_indices.end, track_collection.RangeCount());
@@ -367,4 +369,21 @@ void GridItemData::ComputeOutOfFlowItemPlacement(
   }
 }
 
+void GridItems::RemoveSubgriddedItems() {
+  wtf_size_t new_item_count = 0;
+  for (const auto& grid_item : item_data) {
+    if (grid_item.is_subgridded_to_parent_grid)
+      break;
+    ++new_item_count;
+  }
+
+#if DCHECK_IS_ON()
+  for (wtf_size_t i = new_item_count; i < item_data.size(); ++i)
+    DCHECK(item_data[i].is_subgridded_to_parent_grid);
+#endif
+
+  reordered_item_indices.Shrink(new_item_count);
+  item_data.Shrink(new_item_count);
+}
+
 }  // namespace blink

third_party/blink/renderer/core/layout/ng/grid/ng_grid_item.h

@@ -154,6 +154,7 @@ struct CORE_EXPORT GridItemData {
   bool is_block_axis_overflow_safe : 1;
   bool is_inline_axis_overflow_safe : 1;
   bool is_sizing_dependent_on_block_size : 1;
+  bool is_subgridded_to_parent_grid : 1;
 
   AxisEdge inline_axis_alignment;
   AxisEdge block_axis_alignment;
@@ -226,7 +227,7 @@ struct CORE_EXPORT GridItems {
   }
   Iterator end() { return Iterator(&item_data, reordered_item_indices.end()); }
 
-  void Append(const GridItemData& new_item_data) {
+  void Append(GridItemData&& new_item_data) {
     reordered_item_indices.push_back(item_data.size());
     item_data.emplace_back(new_item_data);
   }
@@ -235,6 +236,8 @@ struct CORE_EXPORT GridItems {
     item_data.ReserveCapacity(capacity);
   }
 
+  void RemoveSubgriddedItems();
+
   wtf_size_t Size() const { return item_data.size(); }
   bool IsEmpty() const { return item_data.IsEmpty(); }