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, 4 insertions, 1 deletions

diff --git a/layout/generic/nsIScrollableFrame.h b/layout/generic/nsIScrollableFrame.h
index b7e3caf46a..20a598452f 100644
--- a/layout/generic/nsIScrollableFrame.h
+++ b/layout/generic/nsIScrollableFrame.h
@@ -440,13 +440,16 @@ public:
   /**
    * Determine if we should build a scrollable layer for this scroll frame and
    * return the result. It will also record this result on the scroll frame.
+   * Pass the visible rect in aVisibleRect. On return it will be set to the
+   * displayport if there is one.
    * Pass the dirty rect in aDirtyRect. On return it will be set to the
-   * displayport if there is one (ie the dirty rect that should be used).
+   * dirty rect inside the displayport (ie the dirty rect that should be used).
    * This function may create a display port where one did not exist before if
    * aAllowCreateDisplayPort is true. It is only allowed to be false if there
    * has been a call with it set to true before on the same paint.
    */
   virtual bool DecideScrollableLayer(nsDisplayListBuilder* aBuilder,
+                                     nsRect* aVisibleRect,
                                      nsRect* aDirtyRect,
                                      bool aAllowCreateDisplayPort) = 0;