diff -r 000000000000 -r 6474c204b198 layout/xul/tree/nsTreeColFrame.cpp
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/layout/xul/tree/nsTreeColFrame.cpp	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,200 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* 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 "nsCOMPtr.h"
+#include "nsTreeColFrame.h"
+#include "nsGkAtoms.h"
+#include "nsIContent.h"
+#include "nsStyleContext.h"
+#include "nsNameSpaceManager.h"
+#include "nsIBoxObject.h"
+#include "nsTreeBoxObject.h"
+#include "nsIDOMElement.h"
+#include "nsITreeBoxObject.h"
+#include "nsITreeColumns.h"
+#include "nsIDOMXULTreeElement.h"
+#include "nsDisplayList.h"
+#include "nsTreeBodyFrame.h"
+
+//
+// NS_NewTreeColFrame
+//
+// Creates a new col frame
+//
+nsIFrame*
+NS_NewTreeColFrame(nsIPresShell* aPresShell, nsStyleContext* aContext)
+{
+  return new (aPresShell) nsTreeColFrame(aPresShell, aContext);
+}
+
+NS_IMPL_FRAMEARENA_HELPERS(nsTreeColFrame)
+
+// Destructor
+nsTreeColFrame::~nsTreeColFrame()
+{
+}
+
+void
+nsTreeColFrame::Init(nsIContent*      aContent,
+                     nsIFrame*        aParent,
+                     nsIFrame*        aPrevInFlow)
+{
+  nsBoxFrame::Init(aContent, aParent, aPrevInFlow);
+  InvalidateColumns();
+}
+
+void
+nsTreeColFrame::DestroyFrom(nsIFrame* aDestructRoot)
+{
+  InvalidateColumns(false);
+  nsBoxFrame::DestroyFrom(aDestructRoot);
+}
+
+class nsDisplayXULTreeColSplitterTarget : public nsDisplayItem {
+public:
+  nsDisplayXULTreeColSplitterTarget(nsDisplayListBuilder* aBuilder,
+                                    nsIFrame* aFrame) :
+    nsDisplayItem(aBuilder, aFrame) {
+    MOZ_COUNT_CTOR(nsDisplayXULTreeColSplitterTarget);
+  }
+#ifdef NS_BUILD_REFCNT_LOGGING
+  virtual ~nsDisplayXULTreeColSplitterTarget() {
+    MOZ_COUNT_DTOR(nsDisplayXULTreeColSplitterTarget);
+  }
+#endif
+
+  virtual void HitTest(nsDisplayListBuilder* aBuilder, const nsRect& aRect,
+                       HitTestState* aState,
+                       nsTArray<nsIFrame*> *aOutFrames) MOZ_OVERRIDE;
+  NS_DISPLAY_DECL_NAME("XULTreeColSplitterTarget", TYPE_XUL_TREE_COL_SPLITTER_TARGET)
+};
+
+void
+nsDisplayXULTreeColSplitterTarget::HitTest(nsDisplayListBuilder* aBuilder, const nsRect& aRect,
+                                           HitTestState* aState, nsTArray<nsIFrame*> *aOutFrames)
+{
+  nsRect rect = aRect - ToReferenceFrame();
+  // If we are in either in the first 4 pixels or the last 4 pixels, we're going to
+  // do something really strange.  Check for an adjacent splitter.
+  bool left = false;
+  bool right = false;
+  if (mFrame->GetSize().width - nsPresContext::CSSPixelsToAppUnits(4) <= rect.XMost()) {
+    right = true;
+  } else if (nsPresContext::CSSPixelsToAppUnits(4) > rect.x) {
+    left = true;
+  }
+
+  // Swap left and right for RTL trees in order to find the correct splitter
+  if (mFrame->StyleVisibility()->mDirection == NS_STYLE_DIRECTION_RTL) {
+    bool tmp = left;
+    left = right;
+    right = tmp;
+  }
+
+  if (left || right) {
+    // We are a header. Look for the correct splitter.
+    nsIFrame* child;
+    if (left)
+      child = mFrame->GetPrevSibling();
+    else
+      child = mFrame->GetNextSibling();
+
+    if (child && child->GetContent()->NodeInfo()->Equals(nsGkAtoms::splitter,
+                                                         kNameSpaceID_XUL)) {
+      aOutFrames->AppendElement(child);
+    }
+  }
+
+}
+
+void
+nsTreeColFrame::BuildDisplayListForChildren(nsDisplayListBuilder*   aBuilder,
+                                            const nsRect&           aDirtyRect,
+                                            const nsDisplayListSet& aLists)
+{
+  if (!aBuilder->IsForEventDelivery()) {
+    nsBoxFrame::BuildDisplayListForChildren(aBuilder, aDirtyRect, aLists);
+    return;
+  }
+  
+  nsDisplayListCollection set;
+  nsBoxFrame::BuildDisplayListForChildren(aBuilder, aDirtyRect, set);
+  
+  WrapListsInRedirector(aBuilder, set, aLists);
+
+  aLists.Content()->AppendNewToTop(new (aBuilder)
+    nsDisplayXULTreeColSplitterTarget(aBuilder, this));
+}
+
+nsresult
+nsTreeColFrame::AttributeChanged(int32_t aNameSpaceID,
+                                 nsIAtom* aAttribute,
+                                 int32_t aModType)
+{
+  nsresult rv = nsBoxFrame::AttributeChanged(aNameSpaceID, aAttribute,
+                                             aModType);
+
+  if (aAttribute == nsGkAtoms::ordinal || aAttribute == nsGkAtoms::primary) {
+    InvalidateColumns();
+  }
+
+  return rv;
+}
+
+void
+nsTreeColFrame::SetBounds(nsBoxLayoutState& aBoxLayoutState,
+                          const nsRect& aRect,
+                          bool aRemoveOverflowArea) {
+  nscoord oldWidth = mRect.width;
+
+  nsBoxFrame::SetBounds(aBoxLayoutState, aRect, aRemoveOverflowArea);
+  if (mRect.width != oldWidth) {
+    nsITreeBoxObject* treeBoxObject = GetTreeBoxObject();
+    if (treeBoxObject) {
+      treeBoxObject->Invalidate();
+    }
+  }
+}
+
+nsITreeBoxObject*
+nsTreeColFrame::GetTreeBoxObject()
+{
+  nsITreeBoxObject* result = nullptr;
+
+  nsIContent* parent = mContent->GetParent();
+  if (parent) {
+    nsIContent* grandParent = parent->GetParent();
+    nsCOMPtr<nsIDOMXULElement> treeElement = do_QueryInterface(grandParent);
+    if (treeElement) {
+      nsCOMPtr<nsIBoxObject> boxObject;
+      treeElement->GetBoxObject(getter_AddRefs(boxObject));
+
+      nsCOMPtr<nsITreeBoxObject> treeBoxObject = do_QueryInterface(boxObject);
+      result = treeBoxObject.get();
+    }
+  }
+  return result;
+}
+
+void
+nsTreeColFrame::InvalidateColumns(bool aCanWalkFrameTree)
+{
+  nsITreeBoxObject* treeBoxObject = GetTreeBoxObject();
+  if (treeBoxObject) {
+    nsCOMPtr<nsITreeColumns> columns;
+
+    if (aCanWalkFrameTree) {
+      treeBoxObject->GetColumns(getter_AddRefs(columns));
+    } else {
+      nsTreeBodyFrame* body = static_cast<nsTreeBoxObject*>(treeBoxObject)->GetCachedTreeBody();
+      if (body) {
+        columns = body->Columns();
+      }
+    }
+
+    if (columns)
+      columns->InvalidateColumns();
+  }
+}