Bug 1342801 - Store the 'writing-mode' used value on nsIFrame and make GetWritingMode non-virtual. r=jfkthame

MozReview-Commit-ID: HPhuxjDbOdh

layout/generic/ViewportFrame.h

@@ -38,15 +38,6 @@ public:
                     nsContainerFrame* aParent,
                     nsIFrame*         aPrevInFlow) override;
 
-  virtual mozilla::WritingMode GetWritingMode() const override
-  {
-    nsIFrame* firstChild = mFrames.FirstChild();
-    if (firstChild) {
-      return firstChild->GetWritingMode();
-    }
-    return nsIFrame::GetWritingMode();
-  }
-
 #ifdef DEBUG
   virtual void AppendFrames(ChildListID     aListID,
                             nsFrameList&    aFrameList) override;

layout/generic/nsCanvasFrame.cpp

@@ -182,7 +182,6 @@ nsCanvasFrame::SetHasFocus(bool aHasFocus)
   return NS_OK;
 }
 
-#ifdef DEBUG
 void
 nsCanvasFrame::SetInitialChildList(ChildListID     aListID,
                                    nsFrameList&    aChildList)
@@ -191,12 +190,14 @@ nsCanvasFrame::SetInitialChildList(ChildListID     aListID,
                aChildList.IsEmpty() || aChildList.OnlyChild(),
                "Primary child list can have at most one frame in it");
   nsContainerFrame::SetInitialChildList(aListID, aChildList);
+  MaybePropagateRootElementWritingMode();
 }
 
 void
 nsCanvasFrame::AppendFrames(ChildListID     aListID,
                             nsFrameList&    aFrameList)
 {
+#ifdef DEBUG
   MOZ_ASSERT(aListID == kPrincipalList, "unexpected child list");
   if (!mFrames.IsEmpty()) {
     for (nsFrameList::Enumerator e(aFrameList); !e.AtEnd(); e.Next()) {
@@ -207,7 +208,9 @@ nsCanvasFrame::AppendFrames(ChildListID     aListID,
     }
   }
   nsFrame::VerifyDirtyBitSet(aFrameList);
+#endif
   nsContainerFrame::AppendFrames(aListID, aFrameList);
+  MaybePropagateRootElementWritingMode();
 }
 
 void
@@ -219,8 +222,10 @@ nsCanvasFrame::InsertFrames(ChildListID     aListID,
   // as appending
   MOZ_ASSERT(!aPrevFrame, "unexpected previous sibling frame");
   AppendFrames(aListID, aFrameList);
+  MaybePropagateRootElementWritingMode();
 }
 
+#ifdef DEBUG
 void
 nsCanvasFrame::RemoveFrame(ChildListID     aListID,
                            nsIFrame*       aOldFrame)
@@ -802,6 +807,17 @@ nsCanvasFrame::GetContentForEvent(WidgetEvent* aEvent,
   return rv;
 }
 
+void
+nsCanvasFrame::MaybePropagateRootElementWritingMode()
+{
+  nsIFrame* child = PrincipalChildList().FirstChild();
+  if (child && child->GetContent() &&
+      child->GetContent() == PresContext()->Document()->GetRootElement()) {
+    nsIFrame* childPrimary = child->GetContent()->GetPrimaryFrame();
+    PropagateRootElementWritingMode(childPrimary->GetWritingMode());
+  }
+}
+
 #ifdef DEBUG_FRAME_DUMP
 nsresult
 nsCanvasFrame::GetFrameName(nsAString& aResult) const

layout/generic/nsCanvasFrame.h

@@ -44,12 +44,6 @@ public:
 
   virtual void DestroyFrom(nsIFrame* aDestructRoot) override;
 
-  mozilla::WritingMode GetWritingMode() const override
-  {
-    return nsFrame::GetWritingModeDeferringToRootElem();
-  }
-
-#ifdef DEBUG
   virtual void SetInitialChildList(ChildListID     aListID,
                                    nsFrameList&    aChildList) override;
   virtual void AppendFrames(ChildListID     aListID,
@@ -57,6 +51,7 @@ public:
   virtual void InsertFrames(ChildListID     aListID,
                             nsIFrame*       aPrevFrame,
                             nsFrameList&    aFrameList) override;
+#ifdef DEBUG
   virtual void RemoveFrame(ChildListID     aListID,
                            nsIFrame*       aOldFrame) override;
 #endif
@@ -125,6 +120,10 @@ public:
   nsRect CanvasArea() const;
 
 protected:
+  // Utility function to propagate the WritingMode from our first child to
+  // 'this' and all its ancestors.
+  void MaybePropagateRootElementWritingMode();
+
   // Data members
   bool                      mDoPaintFocus;
   bool                      mAddedScrollPositionListener;

layout/generic/nsFrame.cpp

@@ -434,6 +434,7 @@ nsFrame::nsFrame(nsStyleContext* aContext)
 
   mState = NS_FRAME_FIRST_REFLOW | NS_FRAME_IS_DIRTY;
   mStyleContext = aContext;
+  mWritingMode = WritingMode(mStyleContext);
   mStyleContext->AddRef();
 #ifdef DEBUG
   mStyleContext->FrameAddRef();
@@ -559,6 +560,8 @@ nsFrame::Init(nsIContent*       aContent,
   }
 
   if (aPrevInFlow) {
+    mWritingMode = aPrevInFlow->GetWritingMode();
+
     // Make sure the general flags bits are the same
     nsFrameState state = aPrevInFlow->GetStateBits();
 
@@ -3083,19 +3086,6 @@ nsFrame::FireDOMEvent(const nsAString& aDOMEventName, nsIContent *aContent)
   }
 }
 
-WritingMode
-nsFrame::GetWritingModeDeferringToRootElem() const
-{
-  Element* rootElem = PresContext()->Document()->GetRootElement();
-  if (rootElem) {
-    nsIFrame* primaryFrame = rootElem->GetPrimaryFrame();
-    if (primaryFrame) {
-      return primaryFrame->GetWritingMode();
-    }
-  }
-  return nsIFrame::GetWritingMode();
-}
-
 nsresult
 nsFrame::HandleEvent(nsPresContext* aPresContext, 
                      WidgetGUIEvent* aEvent,

layout/generic/nsFrame.h

@@ -688,8 +688,6 @@ protected:
   // Fire DOM event. If no aContent argument use frame's mContent.
   void FireDOMEvent(const nsAString& aDOMEventName, nsIContent *aContent = nullptr);
 
-  mozilla::WritingMode GetWritingModeDeferringToRootElem() const;
-
 private:
   void BoxReflow(nsBoxLayoutState& aState,
                  nsPresContext*    aPresContext,

layout/generic/nsGfxScrollFrame.cpp

@@ -157,7 +157,7 @@ nsHTMLScrollFrame::SetInitialChildList(ChildListID  aListID,
                                        nsFrameList& aChildList)
 {
   nsContainerFrame::SetInitialChildList(aListID, aChildList);
-  mHelper.ReloadChildFrames();
+  ReloadChildFrames();
 }
 
 
@@ -167,7 +167,7 @@ nsHTMLScrollFrame::AppendFrames(ChildListID  aListID,
 {
   NS_ASSERTION(aListID == kPrincipalList, "Only main list supported");
   mFrames.AppendFrames(nullptr, aFrameList);
-  mHelper.ReloadChildFrames();
+  ReloadChildFrames();
 }
 
 void
@@ -179,7 +179,7 @@ nsHTMLScrollFrame::InsertFrames(ChildListID aListID,
   NS_ASSERTION(!aPrevFrame || aPrevFrame->GetParent() == this,
                "inserting after sibling frame with different parent");
   mFrames.InsertFrames(nullptr, aPrevFrame, aFrameList);
-  mHelper.ReloadChildFrames();
+  ReloadChildFrames();
 }
 
 void
@@ -188,7 +188,7 @@ nsHTMLScrollFrame::RemoveFrame(ChildListID aListID,
 {
   NS_ASSERTION(aListID == kPrincipalList, "Only main list supported");
   mFrames.DestroyFrame(aOldFrame);
-  mHelper.ReloadChildFrames();
+  ReloadChildFrames();
 }
 
 nsSplittableType

layout/generic/nsGfxScrollFrame.h

@@ -676,14 +676,6 @@ public:
   NS_DECL_QUERYFRAME
   NS_DECL_FRAMEARENA_HELPERS
 
-  virtual mozilla::WritingMode GetWritingMode() const override
-  {
-    if (mHelper.mScrolledFrame) {
-      return mHelper.mScrolledFrame->GetWritingMode();
-    }
-    return nsIFrame::GetWritingMode();
-  }
-
   virtual void BuildDisplayList(nsDisplayListBuilder*   aBuilder,
                                 const nsRect&           aDirtyRect,
                                 const nsDisplayListSet& aLists) override {
@@ -1076,6 +1068,14 @@ protected:
    */
   virtual bool ShouldPropagateComputedBSizeToScrolledContent() const { return true; }
 
+  void ReloadChildFrames()
+  {
+    mHelper.ReloadChildFrames();
+    if (mHelper.mScrolledFrame) {
+      mWritingMode = mHelper.mScrolledFrame->GetWritingMode();
+    }
+  }
+
 private:
   friend class mozilla::ScrollFrameHelper;
   ScrollFrameHelper mHelper;

layout/generic/nsIFrame.h

@@ -787,10 +787,15 @@ public:
 
   /**
    * The frame's writing-mode, used for logical layout computations.
+   * It's usually the 'writing-mode' computed value, but there are exceptions:
+   *   * inner table frames copy the value from the table frame
+   *     (@see nsTableRowGroupFrame::Init, nsTableRowFrame::Init etc)
+   *   * the root element frame propagates its value to its ancestors
+   *     (@see nsCanvasFrame::MaybePropagateRootElementWritingMode)
+   *   * a scrolled frame propagates its value to its ancestor scroll frame
+   *     (@see nsHTMLScrollFrame::ReloadChildFrames)
    */
-  virtual mozilla::WritingMode GetWritingMode() const {
-    return mozilla::WritingMode(StyleContext());
-  }
+  mozilla::WritingMode GetWritingMode() const { return mWritingMode; }
 
   /**
    * Construct a writing mode for line layout in this frame.  This is
@@ -3589,6 +3594,11 @@ private:
   }
 
 protected:
+  /**
+   * Copies aRootElemWM to mWritingMode on 'this' and all its ancestors.
+   */
+  inline void PropagateRootElementWritingMode(mozilla::WritingMode aRootElemWM);
+
   void MarkInReflow() {
 #ifdef DEBUG_dbaron_off
     // bug 81268
@@ -3628,6 +3638,9 @@ protected:
     VisualDeltas mVisualDeltas;
   } mOverflow;
 
+  /** @see GetWritingMode() */
+  mozilla::WritingMode mWritingMode;
+
   // Helpers
   /**
    * Can we stop inside this frame when we're skipping non-rendered whitespace?

layout/generic/nsIFrameInlines.h

@@ -160,4 +160,13 @@ nsIFrame::BaselineBOffset(mozilla::WritingMode aWM,
   return SynthesizeBaselineBOffsetFromBorderBox(aWM, aBaselineGroup);
 }
 
+void
+nsIFrame::PropagateRootElementWritingMode(mozilla::WritingMode aRootElemWM)
+{
+  MOZ_ASSERT(GetType() == nsGkAtoms::canvasFrame);
+  for (auto f = this; f; f = f->GetParent()) {
+    f->mWritingMode = aRootElemWM;
+  }
+}
+
 #endif

layout/generic/nsPageContentFrame.h

@@ -44,11 +44,6 @@ public:
    */
   virtual nsIAtom* GetType() const override;
 
-  mozilla::WritingMode GetWritingMode() const override
-  {
-    return nsFrame::GetWritingModeDeferringToRootElem();
-  }
-
 #ifdef DEBUG_FRAME_DUMP
   // Debugging
   virtual nsresult  GetFrameName(nsAString& aResult) const override;

layout/generic/nsPageFrame.h

@@ -32,11 +32,6 @@ public:
                                 const nsRect&           aDirtyRect,
                                 const nsDisplayListSet& aLists) override;
 
-  mozilla::WritingMode GetWritingMode() const override
-  {
-    return nsFrame::GetWritingModeDeferringToRootElem();
-  }
-
   /**
    * Get the "type" of the frame
    *

layout/generic/nsSimplePageSequenceFrame.h

@@ -60,11 +60,6 @@ public:
   NS_DECL_QUERYFRAME
   NS_DECL_FRAMEARENA_HELPERS
 
-  mozilla::WritingMode GetWritingMode() const override
-  {
-    return nsFrame::GetWritingModeDeferringToRootElem();
-  }
-
   // nsIFrame
   void Reflow(nsPresContext* aPresContext,
               ReflowOutput& aDesiredSize,

layout/style/nsStyleStruct.cpp

@@ -3610,6 +3610,8 @@ nsStyleVisibility::CalcDifference(const nsStyleVisibility& aNewData) const
     // It's important that a change in mWritingMode results in frame
     // reconstruction, because it may affect intrinsic size (see
     // nsSubDocumentFrame::GetIntrinsicISize/BSize).
+    // Also, the used writing-mode value is now a field on nsIFrame and some
+    // classes (e.g. table rows/cells) copy their value from an ancestor.
     hint |= nsChangeHint_ReconstructFrame;
   } else {
     if ((mImageOrientation != aNewData.mImageOrientation)) {

layout/tables/nsTableCellFrame.cpp

@@ -92,6 +92,13 @@ nsTableCellFrame::Init(nsIContent*       aContent,
     int32_t           colIndex;
     cellFrame->GetColIndex(colIndex);
     SetColIndex(colIndex);
+  } else {
+    // Although the spec doesn't say that writing-mode is not applied to
+    // table-cells, we still override style value here because we want to
+    // make effective writing mode of table structure frames consistent
+    // within a table. The content inside table cells is reflowed by an
+    // anonymous block, hence their writing mode is not affected.
+    mWritingMode = GetTableFrame()->GetWritingMode();
   }
 }
 

layout/tables/nsTableCellFrame.h

@@ -136,14 +136,6 @@ public:
   virtual nsresult GetFrameName(nsAString& aResult) const override;
 #endif
 
-  // Although the spec doesn't say that writing-mode is not applied to
-  // table-cells, we still override this method here because we want to
-  // make effective writing mode of table structure frames consistent
-  // within a table. The content inside table cells is reflowed by an
-  // anonymous block, hence their writing mode is not affected.
-  virtual mozilla::WritingMode GetWritingMode() const override
-    { return GetTableFrame()->GetWritingMode(); }
-
   void BlockDirAlignChild(mozilla::WritingMode aWM, nscoord aMaxAscent);
 
   /*

layout/tables/nsTableColFrame.h

@@ -33,27 +33,20 @@ public:
   friend nsTableColFrame* NS_NewTableColFrame(nsIPresShell* aPresShell,
                                               nsStyleContext*  aContext);
 
-  nsTableColGroupFrame* GetTableColGroupFrame() const
+  // nsIFrame overrides
+  virtual void Init(nsIContent*       aContent,
+                    nsContainerFrame* aParent,
+                    nsIFrame*         aPrevInFlow) override
   {
-    nsIFrame* parent = GetParent();
-    MOZ_ASSERT(parent && parent->GetType() == nsGkAtoms::tableColGroupFrame);
-    return static_cast<nsTableColGroupFrame*>(parent);
-  }
-
-  nsTableFrame* GetTableFrame() const
-  {
-    return GetTableColGroupFrame()->GetTableFrame();
+    nsSplittableFrame::Init(aContent, aParent, aPrevInFlow);
+    if (!aPrevInFlow) {
+      mWritingMode = GetTableFrame()->GetWritingMode();
+    }
   }
 
   /** @see nsIFrame::DidSetStyleContext */
   virtual void DidSetStyleContext(nsStyleContext* aOldStyleContext) override;
 
-  int32_t GetColIndex() const;
-
-  void SetColIndex (int32_t aColIndex);
-
-  nsTableColFrame* GetNextCol() const;
-
   virtual void Reflow(nsPresContext*           aPresContext,
                       ReflowOutput&     aDesiredSize,
                       const ReflowInput& aReflowInput,
@@ -79,8 +72,23 @@ public:
 
   virtual nsSplittableType GetSplittableType() const override;
 
-  virtual mozilla::WritingMode GetWritingMode() const override
-    { return GetTableFrame()->GetWritingMode(); }
+  nsTableColGroupFrame* GetTableColGroupFrame() const
+  {
+    nsIFrame* parent = GetParent();
+    MOZ_ASSERT(parent && parent->GetType() == nsGkAtoms::tableColGroupFrame);
+    return static_cast<nsTableColGroupFrame*>(parent);
+  }
+
+  nsTableFrame* GetTableFrame() const
+  {
+    return GetTableColGroupFrame()->GetTableFrame();
+  }
+
+  int32_t GetColIndex() const;
+
+  void SetColIndex (int32_t aColIndex);
+
+  nsTableColFrame* GetNextCol() const;
 
   /** return the number of the columns the col represents.  always >= 1 */
   int32_t GetSpan();

layout/tables/nsTableColGroupFrame.h

@@ -16,16 +16,12 @@ class nsTableColFrame;
 /**
  * nsTableColGroupFrame
  * data structure to maintain information about a single table cell's frame
- *
- * @author  sclark
  */
 class nsTableColGroupFrame final : public nsContainerFrame
 {
 public:
   NS_DECL_FRAMEARENA_HELPERS
 
-  // default constructor supplied by the compiler
-
   /** instantiate a new instance of nsTableRowFrame.
     * @param aPresShell the pres shell for this frame
     *
@@ -34,6 +30,17 @@ public:
   friend nsTableColGroupFrame* NS_NewTableColGroupFrame(nsIPresShell* aPresShell,
                                                         nsStyleContext* aContext);
 
+  // nsIFrame overrides
+  virtual void Init(nsIContent*       aContent,
+                    nsContainerFrame* aParent,
+                    nsIFrame*         aPrevInFlow) override
+  {
+    nsContainerFrame::Init(aContent, aParent, aPrevInFlow);
+    if (!aPrevInFlow) {
+      mWritingMode = GetTableFrame()->GetWritingMode();
+    }
+  }
+
   nsTableFrame* GetTableFrame() const
   {
     nsIFrame* parent = GetParent();
@@ -116,9 +123,6 @@ public:
    */
   virtual nsIAtom* GetType() const override;
 
-  virtual mozilla::WritingMode GetWritingMode() const override
-    { return GetTableFrame()->GetWritingMode(); }
-
   /** Add column frames to the table storages: colframe cache and cellmap
     * this doesn't change the mFrames of the colgroup frame.
     * @param aFirstColIndex - the index at which aFirstFrame should be inserted

layout/tables/nsTableRowFrame.cpp

@@ -169,6 +169,8 @@ nsTableRowFrame::Init(nsIContent*       aContent,
     nsTableRowFrame* rowFrame = (nsTableRowFrame*)aPrevInFlow;
 
     SetRowIndex(rowFrame->GetRowIndex());
+  } else {
+    mWritingMode = GetTableFrame()->GetWritingMode();
   }
 }
 

layout/tables/nsTableRowFrame.h

@@ -116,9 +116,6 @@ public:
   virtual nsresult GetFrameName(nsAString& aResult) const override;
 #endif
 
-  virtual mozilla::WritingMode GetWritingMode() const override
-    { return GetTableFrame()->GetWritingMode(); }
- 
   void UpdateBSize(nscoord           aBSize,
                    nscoord           aAscent,
                    nscoord           aDescent,

layout/tables/nsTableRowGroupFrame.h

@@ -51,11 +51,15 @@ public:
                                                         nsStyleContext* aContext);
   virtual ~nsTableRowGroupFrame();
 
-  nsTableFrame* GetTableFrame() const
+  // nsIFrame overrides
+  virtual void Init(nsIContent*       aContent,
+                    nsContainerFrame* aParent,
+                    nsIFrame*         aPrevInFlow) override
   {
-    nsIFrame* parent = GetParent();
-    MOZ_ASSERT(parent && parent->GetType() == nsGkAtoms::tableFrame);
-    return static_cast<nsTableFrame*>(parent);
+    nsContainerFrame::Init(aContent, aParent, aPrevInFlow);
+    if (!aPrevInFlow) {
+      mWritingMode = GetTableFrame()->GetWritingMode();
+    }
   }
 
   virtual void DestroyFrom(nsIFrame* aDestructRoot) override;
@@ -102,15 +106,19 @@ public:
    */
   virtual nsIAtom* GetType() const override;
 
-  nsTableRowFrame* GetFirstRow();
-  nsTableRowFrame* GetLastRow();
-
 #ifdef DEBUG_FRAME_DUMP
   virtual nsresult GetFrameName(nsAString& aResult) const override;
 #endif
 
-  virtual mozilla::WritingMode GetWritingMode() const override
-    { return GetTableFrame()->GetWritingMode(); }
+  nsTableRowFrame* GetFirstRow();
+  nsTableRowFrame* GetLastRow();
+
+  nsTableFrame* GetTableFrame() const
+  {
+    nsIFrame* parent = GetParent();
+    MOZ_ASSERT(parent && parent->GetType() == nsGkAtoms::tableFrame);
+    return static_cast<nsTableFrame*>(parent);
+  }
 
   /** return the number of child rows (not necessarily == number of child frames) */
   int32_t GetRowCount();