1 files changed, 97 insertions, 0 deletions
diff --git a/dom/grid/Grid.cpp b/dom/grid/Grid.cpp
new file mode 100644
index 0000000000..fd8eb0817a
--- /dev/null
+++ b/dom/grid/Grid.cpp
@@ -0,0 +1,97 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "Grid.h"
+
+#include "GridArea.h"
+#include "GridDimension.h"
+#include "mozilla/dom/Element.h"
+#include "mozilla/dom/GridBinding.h"
+#include "nsGridContainerFrame.h"
+#include "nsTHashSet.h"
+
+namespace mozilla::dom {
+
+NS_IMPL_CYCLE_COLLECTION_WRAPPERCACHE(Grid, mParent, mRows, mCols, mAreas)
+NS_IMPL_CYCLE_COLLECTING_ADDREF(Grid)
+NS_IMPL_CYCLE_COLLECTING_RELEASE(Grid)
+NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION(Grid)
+  NS_WRAPPERCACHE_INTERFACE_MAP_ENTRY
+  NS_INTERFACE_MAP_ENTRY(nsISupports)
+NS_INTERFACE_MAP_END
+
+Grid::Grid(nsISupports* aParent, nsGridContainerFrame* aFrame)
+    : mParent(do_QueryInterface(aParent)),
+      mRows(new GridDimension(this)),
+      mCols(new GridDimension(this)) {
+  MOZ_ASSERT(aFrame,
+             "Should never be instantiated with a null nsGridContainerFrame");
+
+  // Construct areas first, because lines may need to reference them
+  // to extract additional names for boundary lines.
+
+  // Add implicit areas first. Track the names that we add here, because
+  // we will ignore future explicit areas with the same name.
+  nsTHashSet<RefPtr<nsAtom>> namesSeen;
+  nsGridContainerFrame::ImplicitNamedAreas* implicitAreas =
+      aFrame->GetImplicitNamedAreas();
+  if (implicitAreas) {
+    for (auto iter = implicitAreas->iter(); !iter.done(); iter.next()) {
+      auto& areaInfo = iter.get().value();
+      namesSeen.Insert(areaInfo.name.AsAtom());
+      GridArea* area =
+          new GridArea(this, areaInfo.name.AsAtom(), GridDeclaration::Implicit,
+                       areaInfo.rows.start, areaInfo.rows.end,
+                       areaInfo.columns.start, areaInfo.columns.end);
+      mAreas.AppendElement(area);
+    }
+  }
+
+  // Add explicit areas next, as long as they don't have the same name
+  // as the implicit areas, because the implicit values override what was
+  // initially available in the explicit areas.
+  if (auto* explicitAreas = aFrame->GetExplicitNamedAreas()) {
+    for (auto& areaInfo : explicitAreas->AsSpan()) {
+      if (!namesSeen.Contains(areaInfo.name.AsAtom())) {
+        GridArea* area = new GridArea(
+            this, areaInfo.name.AsAtom(), GridDeclaration::Explicit,
+            areaInfo.rows.start, areaInfo.rows.end, areaInfo.columns.start,
+            areaInfo.columns.end);
+        mAreas.AppendElement(area);
+      }
+    }
+  }
+
+  // Now construct the tracks and lines.
+  const ComputedGridTrackInfo* rowTrackInfo = aFrame->GetComputedTemplateRows();
+  const ComputedGridLineInfo* rowLineInfo =
+      aFrame->GetComputedTemplateRowLines();
+  mRows->SetTrackInfo(rowTrackInfo);
+  mRows->SetLineInfo(rowTrackInfo, rowLineInfo, mAreas, true);
+
+  const ComputedGridTrackInfo* columnTrackInfo =
+      aFrame->GetComputedTemplateColumns();
+  const ComputedGridLineInfo* columnLineInfo =
+      aFrame->GetComputedTemplateColumnLines();
+  mCols->SetTrackInfo(columnTrackInfo);
+  mCols->SetLineInfo(columnTrackInfo, columnLineInfo, mAreas, false);
+}
+
+Grid::~Grid() = default;
+
+JSObject* Grid::WrapObject(JSContext* aCx, JS::Handle<JSObject*> aGivenProto) {
+  return Grid_Binding::Wrap(aCx, this, aGivenProto);
+}
+
+GridDimension* Grid::Rows() const { return mRows; }
+
+GridDimension* Grid::Cols() const { return mCols; }
+
+void Grid::GetAreas(nsTArray<RefPtr<GridArea>>& aAreas) const {
+  aAreas = mAreas.Clone();
+}
+
+}  // namespace mozilla::dom