Issue #1355 - Better way to create display items for column backgrounds

Part 1: Remove current table item, as it's never set.

Part 2: Get rid of generic table painting code, and handle each class separately.

Part 4: Hoist outline skipping into col(group) frame code.

Part 5: Skip box-shadow for table column and column groups.

Part 6: Store column and column group backgrounds separately, and then append them before the rest of the table contents.

Part 7: Pass rects in display list coordinates to AppendBackgroundItemsToTop.

Part 8: Create column and column group background display items as part of the cell's BuildDisplayList.

Part 9: Used cached values instead of calling nsDisplayListBuilder::ToReferenceFrame when possible, since it can be expensive when the requested frame isn't the builder's current frame.

Part 10: Make sure we build display items for table parts where only the normal position is visible, since we may need to create background items for ancestors at that position.

Part 11: Create an AutoBuildingDisplayList when we create background items for table columns and column groups, so that we initialize the invalidation state correctly.

1 files changed, 48 insertions, 47 deletions

diff --git a/layout/tables/nsTableFrame.h b/layout/tables/nsTableFrame.h
index 8a2384134..7fcdcb9d8 100644
--- a/layout/tables/nsTableFrame.h
+++ b/layout/tables/nsTableFrame.h
@@ -72,36 +72,59 @@ private:
   bool mDrawsBackground;
 };
 
-class nsAutoPushCurrentTableItem
-{
-public:
-  nsAutoPushCurrentTableItem() : mBuilder(nullptr) {}
+class nsDisplayTableBackgroundSet {
+ public:
+  nsDisplayList* ColGroupBackgrounds() { return &mColGroupBackgrounds; }
+
+  nsDisplayList* ColBackgrounds() { return &mColBackgrounds; }
+
+  nsDisplayTableBackgroundSet(nsDisplayListBuilder* aBuilder, nsIFrame* aTable)
+      : mBuilder(aBuilder) {
+    mPrevTableBackgroundSet = mBuilder->SetTableBackgroundSet(this);
+    mozilla::DebugOnly<const nsIFrame*> reference =
+        mBuilder->FindReferenceFrameFor(aTable, &mToReferenceFrame);
+    MOZ_ASSERT(nsLayoutUtils::IsAncestorFrameCrossDoc(reference, aTable));
+    mDirtyRect = mBuilder->GetDirtyRect();
+  }
 
-  void Push(nsDisplayListBuilder* aBuilder, nsDisplayTableItem* aPushItem)
-  {
-    mBuilder = aBuilder;
-    mOldCurrentItem = aBuilder->GetCurrentTableItem();
-    aBuilder->SetCurrentTableItem(aPushItem);
-#ifdef DEBUG
-    mPushedItem = aPushItem;
-#endif
+  ~nsDisplayTableBackgroundSet() {
+    mozilla::DebugOnly<nsDisplayTableBackgroundSet*> result =
+        mBuilder->SetTableBackgroundSet(mPrevTableBackgroundSet);
+    MOZ_ASSERT(result == this);
   }
-  ~nsAutoPushCurrentTableItem() {
-    if (!mBuilder)
-      return;
-#ifdef DEBUG
-    NS_ASSERTION(mBuilder->GetCurrentTableItem() == mPushedItem,
-                 "Someone messed with the current table item behind our back!");
-#endif
-    mBuilder->SetCurrentTableItem(mOldCurrentItem);
+
+  /**
+   * Move all display items in our lists to top of the corresponding lists in
+   * the destination.
+   */
+  void MoveTo(const nsDisplayListSet& aDestination) {
+    aDestination.BorderBackground()->AppendToTop(ColGroupBackgrounds());
+    aDestination.BorderBackground()->AppendToTop(ColBackgrounds());
   }
 
-private:
+  void AddColumn(nsTableColFrame* aFrame) { mColumns.AppendElement(aFrame); }
+
+  nsTableColFrame* GetColForIndex(int32_t aIndex) { return mColumns[aIndex]; }
+
+  const nsPoint& TableToReferenceFrame() { return mToReferenceFrame; }
+
+  const nsRect& GetDirtyRect() { return mDirtyRect; }
+
+ private:
+  // This class is only used on stack, so we don't have to worry about leaking
+  // it.  Don't let us be heap-allocated!
+  void* operator new(size_t sz) CPP_THROW_NEW;
+
+ protected:
   nsDisplayListBuilder* mBuilder;
-  nsDisplayTableItem*   mOldCurrentItem;
-#ifdef DEBUG
-  nsDisplayTableItem*   mPushedItem;
-#endif
+  nsDisplayTableBackgroundSet* mPrevTableBackgroundSet;
+
+  nsDisplayList mColGroupBackgrounds;
+  nsDisplayList mColBackgrounds;
+
+  nsTArray<nsTableColFrame*> mColumns;
+  nsPoint mToReferenceFrame;
+  nsRect mDirtyRect;
 };
 
 /* ============================================================================ */
@@ -229,28 +252,6 @@ public:
                                                    nsIFrame* aSourceFrame,
                                                    bool* aDidPassThrough);
 
-  typedef void (* DisplayGenericTablePartTraversal)
-      (nsDisplayListBuilder* aBuilder, nsFrame* aFrame,
-       const nsDisplayListSet& aLists);
-  static void GenericTraversal(nsDisplayListBuilder* aBuilder, nsFrame* aFrame,
-                               const nsDisplayListSet& aLists);
-
-  /**
-   * Helper method to handle display common to table frames, rowgroup frames
-   * and row frames. It creates a background display item for handling events
-   * if necessary, an outline display item if necessary, and displays
-   * all the the frame's children.
-   * @param aDisplayItem the display item created for this part, or null
-   * if this part's border/background painting is delegated to an ancestor
-   * @param aTraversal a function that gets called to traverse the table
-   * part's child frames and add their display list items to a
-   * display list set.
-   */
-  static void DisplayGenericTablePart(nsDisplayListBuilder* aBuilder,
-                                      nsFrame* aFrame,
-                                      const nsDisplayListSet& aLists,
-                                      DisplayGenericTablePartTraversal aTraversal = GenericTraversal);
-
   // Return the closest sibling of aPriorChildFrame (including aPriroChildFrame)
   // of type aChildType.
   static nsIFrame* GetFrameAtOrBefore(nsIFrame*       aParentFrame,