Fixed various incremental reflow bugs (1764,12890,1910,2222) and list bullet painting bug (10675,13599)

layout/generic/nsBlockFrame.h

@@ -115,9 +115,6 @@ public:
                     nsHTMLReflowMetrics&     aDesiredSize,
                     const nsHTMLReflowState& aReflowState,
                     nsReflowStatus&          aStatus);
-  NS_IMETHOD MoveInSpaceManager(nsIPresContext* aPresContext,
-                                nsISpaceManager* aSpaceManager,
-                                nscoord aDeltaX, nscoord aDeltaY);
 
   NS_IMETHOD AttributeChanged(nsIPresContext* aPresContext,
                               nsIContent*     aChild,
@@ -144,6 +141,9 @@ public:
 
   nsIFrame* GetTopBlockChild();
 
+  nsresult UpdateSpaceManager(nsIPresContext* aPresContext,
+                              nsISpaceManager* aSpaceManager);
+
 protected:
   nsBlockFrame();
   virtual ~nsBlockFrame();
@@ -166,10 +166,6 @@ protected:
                  nsISpaceManager* aSpaceManager,
                  nsLineBox* aLine, nscoord aDY);
 
-  void SlideFloaters(nsIPresContext* aPresContext,
-                     nsISpaceManager* aSpaceManager,
-                     nsLineBox* aLine, nscoord aDY);
-
   PRBool DrainOverflowLines();
 
   virtual PRIntn GetSkipSides() const;
@@ -228,10 +224,6 @@ protected:
                       PRBool* aKeepReflowGoing,
                       PRBool aDamageDirtyArea = PR_FALSE);
 
-  virtual void DidReflowLine(nsBlockReflowState& aState,
-                             nsLineBox* aLine,
-                             PRBool aKeepReflowGoing);
-
   nsresult PlaceLine(nsBlockReflowState& aState,
                      nsLineLayout& aLineLayout,
                      nsLineBox* aLine,
@@ -249,8 +241,6 @@ protected:
   // XXX where to go
   PRBool ShouldJustifyLine(nsBlockReflowState& aState, nsLineBox* aLine);
 
-  void FindFloaters(nsLineBox* aLine);
-
   void DeleteLine(nsBlockReflowState& aState, nsLineBox* aLine);
 
   //----------------------------------------
@@ -339,6 +329,7 @@ protected:
 
   void PropogateReflowDamage(nsBlockReflowState& aState,
                              nsLineBox* aLine,
+                             const nsRect& aOldCombinedArea,
                              nscoord aDeltaY);
 
   nsresult ComputeTextRuns(nsIPresContext* aPresContext);

layout/generic/nsLineBox.cpp

@@ -27,7 +27,6 @@ nsLineBox::nsLineBox(nsIFrame* aFrame, PRInt32 aCount, PRUint16 flags)
   mFirstChild = aFrame;
   mChildCount = aCount;
   mState = LINE_IS_DIRTY | flags;
-  mFloaters = nsnull;
   mNext = nsnull;
   mBounds.SetRect(0,0,0,0);
   mCombinedArea.SetRect(0,0,0,0);
@@ -39,19 +38,16 @@ nsLineBox::nsLineBox(nsIFrame* aFrame, PRInt32 aCount, PRUint16 flags)
 
 nsLineBox::~nsLineBox()
 {
-  if (nsnull != mFloaters) {
-    delete mFloaters;
-  }
 }
 
 static void
-ListFloaters(FILE* out, PRInt32 aIndent, nsVoidArray* aFloaters)
+ListFloaters(FILE* out, PRInt32 aIndent, const nsFloaterCacheList& aFloaters)
 {
   nsAutoString frameName;
-  PRInt32 j, i, n = aFloaters->Count();
-  for (i = 0; i < n; i++) {
-    for (j = aIndent; --j >= 0; ) fputs("  ", out);
-    nsPlaceholderFrame* ph = (nsPlaceholderFrame*) aFloaters->ElementAt(i);
+  nsFloaterCache* fc = aFloaters.Head();
+  while (fc) {
+    nsFrame::IndentBy(out, aIndent);
+    nsPlaceholderFrame* ph = fc->mPlaceholder;
     if (nsnull != ph) {
       fprintf(out, "placeholder@%p ", ph);
       nsIFrame* frame = ph->GetOutOfFlowFrame();
@@ -59,8 +55,13 @@ ListFloaters(FILE* out, PRInt32 aIndent, nsVoidArray* aFloaters)
         frame->GetFrameName(frameName);
         fputs(frameName, out);
       }
+      fprintf(out, " %s region={%d,%d,%d,%d}",
+              fc->mIsCurrentLineFloater ? "cl" : "bcl",
+              fc->mRegion.x, fc->mRegion.y,
+              fc->mRegion.width, fc->mRegion.height);
       fprintf(out, "\n");
     }
+    fc = fc->Next();
   }
 }
 
@@ -105,7 +106,7 @@ nsLineBox::List(FILE* out, PRInt32 aIndent) const
   }
 
   for (i = aIndent; --i >= 0; ) fputs("  ", out);
-  if (nsnull != mFloaters) {
+  if (mFloaters.NotEmpty()) {
     fputs("> floaters <\n", out);
     ListFloaters(out, aIndent + 1, mFloaters);
     for (i = aIndent; --i >= 0; ) fputs("  ", out);
@@ -463,3 +464,128 @@ nsLineIterator::FindFrameAt(PRInt32 aLineNumber,
   *aFrameFound = frame;
   return NS_OK;
 }
+
+//----------------------------------------------------------------------
+
+nsFloaterCacheList::~nsFloaterCacheList()
+{
+  nsFloaterCache* floater = mHead;
+  while (floater) {
+    nsFloaterCache* next = floater->mNext;
+    delete floater;
+    floater = next;
+  }
+}
+
+nsFloaterCache*
+nsFloaterCacheList::Tail() const
+{
+  nsFloaterCache* fc = mHead;
+  while (fc) {
+    if (!fc->mNext) {
+      break;
+    }
+    fc = fc->mNext;
+  }
+  return fc;
+}
+
+void
+nsFloaterCacheList::Append(nsFloaterCacheFreeList& aList)
+{
+  nsFloaterCache* tail = Tail();
+  if (tail) {
+    tail->mNext = aList.mHead;
+  }
+  else {
+    mHead = aList.mHead;
+  }
+  aList.mHead = nsnull;
+  aList.mTail = nsnull;
+}
+
+nsFloaterCache*
+nsFloaterCacheList::Find(nsIFrame* aOutOfFlowFrame)
+{
+  nsFloaterCache* fc = mHead;
+  while (fc) {
+    if (fc->mPlaceholder->GetOutOfFlowFrame() == aOutOfFlowFrame) {
+      break;
+    }
+    fc = fc->Next();
+  }
+  return fc;
+}
+
+void
+nsFloaterCacheList::Remove(nsFloaterCache* aElement)
+{
+  nsFloaterCache** fcp = &mHead;
+  nsFloaterCache* fc;
+  while (nsnull != (fc = *fcp)) {
+    if (fc == aElement) {
+      *fcp = fc->mNext;
+      break;
+    }
+    fcp = &fc->mNext;
+  }
+}
+
+//----------------------------------------------------------------------
+
+void
+nsFloaterCacheFreeList::Append(nsFloaterCacheList& aList)
+{
+  if (mTail) {
+    mTail->mNext = aList.mHead;
+  }
+  else {
+    mHead = aList.mHead;
+  }
+  mTail = aList.Tail();
+  aList.mHead = nsnull;
+}
+
+nsFloaterCache*
+nsFloaterCacheFreeList::Alloc()
+{
+  nsFloaterCache* fc = mHead;
+  if (mHead) {
+    if (mHead == mTail) {
+      mHead = mTail = nsnull;
+    }
+    else {
+      mHead = fc->mNext;
+    }
+    fc->mNext = nsnull;
+  }
+  else {
+    fc = new nsFloaterCache();
+  }
+  return fc;
+}
+
+void
+nsFloaterCacheFreeList::Append(nsFloaterCache* aFloater)
+{
+  aFloater->mNext = nsnull;
+  if (mTail) {
+    mTail->mNext = aFloater;
+    mTail = aFloater;
+  }
+  else {
+    mHead = mTail = aFloater;
+  }
+}
+
+//----------------------------------------------------------------------
+
+nsFloaterCache::nsFloaterCache()
+  : mPlaceholder(nsnull),
+    mIsCurrentLineFloater(PR_TRUE),
+    mMargins(0, 0, 0, 0),
+    mOffsets(0, 0, 0, 0),
+    mCombinedArea(0, 0, 0, 0),
+    mNext(nsnull)
+{
+}

layout/generic/nsLineBox.h

@@ -24,16 +24,117 @@
 #include "nsILineIterator.h"
 
 // bits in nsLineBox.mState
-#define LINE_IS_DIRTY                 0x1
-#define LINE_IS_BLOCK                 0x2
+#define LINE_IS_DIRTY               0x1
+#define LINE_IS_BLOCK               0x2
+#define LINE_IS_IMPACTED_BY_FLOATER 0x4
 #ifdef BLOCK_DOES_FIRST_LINE
-#define LINE_IS_FIRST_LINE            0x4
+#define LINE_IS_FIRST_LINE          0x8
 #endif
-#define LINE_WAS_DIRTY                0x8
+#define LINE_WAS_DIRTY              0x10
 
 class nsISpaceManager;
 class nsLineBox;
 
+//----------------------------------------------------------------------
+
+class nsFloaterCache;
+class nsFloaterCacheList;
+class nsFloaterCacheFreeList;
+
+// State cached after reflowing a floater. This state is used during
+// incremental reflow when we avoid reflowing a floater.
+class nsFloaterCache {
+public:
+  nsFloaterCache();
+  ~nsFloaterCache() { }
+
+  nsFloaterCache* Next() const { return mNext; }
+
+  nsPlaceholderFrame* mPlaceholder;     // nsPlaceholderFrame
+
+  // This will be true if the floater was placed on the current line
+  // instead of below the current line.
+  PRBool mIsCurrentLineFloater;
+
+  nsMargin mMargins;                    // computed margins
+
+  nsMargin mOffsets;                    // computed offsets (relative pos)
+
+  // Region in the spacemanager impacted by this floater; the
+  // coordinates are relative to the containing block frame. The
+  // region includes the margins around the floater, but doesn't
+  // include the relative offsets.
+  nsRect mRegion;
+
+  // Combined area for the floater. This will not include the margins
+  // for the floater. Like mRegion, the coordinates are relative to
+  // the containing block frame.
+  nsRect mCombinedArea;
+
+protected:
+  nsFloaterCache* mNext;
+
+  friend class nsFloaterCacheList;
+  friend class nsFloaterCacheFreeList;
+};
+
+//----------------------------------------
+
+class nsFloaterCacheList {
+public:
+  nsFloaterCacheList() : mHead(nsnull) { }
+  ~nsFloaterCacheList();
+
+  PRBool IsEmpty() const {
+    return nsnull == mHead;
+  }
+
+  PRBool NotEmpty() const {
+    return nsnull != mHead;
+  }
+
+  nsFloaterCache* Head() const {
+    return mHead;
+  }
+
+  nsFloaterCache* Tail() const;
+
+  nsFloaterCache* Find(nsIFrame* aOutOfFlowFrame);
+
+  void Remove(nsFloaterCache* aElement);
+
+  void Append(nsFloaterCacheFreeList& aList);
+
+protected:
+  nsFloaterCache* mHead;
+
+  friend class nsFloaterCacheFreeList;
+};
+
+//---------------------------------------
+
+class nsFloaterCacheFreeList : public nsFloaterCacheList {
+public:
+  nsFloaterCacheFreeList() : mTail(nsnull) { }
+  ~nsFloaterCacheFreeList() { }
+
+  // Steal away aList's nsFloaterCache objects and put them on this
+  // free-list.
+  void Append(nsFloaterCacheList& aList);
+
+  void Append(nsFloaterCache* aFloaterCache);
+
+  // Allocate a new nsFloaterCache object
+  nsFloaterCache* Alloc();
+
+protected:
+  nsFloaterCache* mTail;
+
+  friend class nsFloaterCacheList;
+};
+
+//----------------------------------------------------------------------
+
 /**
  * The nsLineBox class represents a horizontal line of frames. It contains
  * enough state to support incremental reflow of the frames, event handling
@@ -92,6 +193,19 @@ public:
     }
   }
 
+  void SetLineIsImpactedByFloater(PRBool aValue) {
+    if (aValue) {
+      mState |= LINE_IS_IMPACTED_BY_FLOATER;
+    }
+    else {
+      mState &= ~LINE_IS_IMPACTED_BY_FLOATER;
+    }
+  }
+
+  PRBool IsImpactedByFloater() const {
+    return 0 != (LINE_IS_IMPACTED_BY_FLOATER & mState);
+  }
+
 #ifdef BLOCK_DOES_FIRST_LINE
   PRBool IsFirstLine() const {
     return 0 != (LINE_IS_FIRST_LINE & mState);
@@ -150,7 +264,7 @@ public:
   nsRect mBounds;
   nsRect mCombinedArea;
   nscoord mCarriedOutBottomMargin;/* XXX switch to 16 bits */
-  nsVoidArray* mFloaters;
+  nsFloaterCacheList mFloaters;
   nsLineBox* mNext;
   nscoord mMaxElementWidth;  // width part of max-element-size
 };

layout/html/base/src/nsBlockFrame.h

@@ -115,9 +115,6 @@ public:
                     nsHTMLReflowMetrics&     aDesiredSize,
                     const nsHTMLReflowState& aReflowState,
                     nsReflowStatus&          aStatus);
-  NS_IMETHOD MoveInSpaceManager(nsIPresContext* aPresContext,
-                                nsISpaceManager* aSpaceManager,
-                                nscoord aDeltaX, nscoord aDeltaY);
 
   NS_IMETHOD AttributeChanged(nsIPresContext* aPresContext,
                               nsIContent*     aChild,
@@ -144,6 +141,9 @@ public:
 
   nsIFrame* GetTopBlockChild();
 
+  nsresult UpdateSpaceManager(nsIPresContext* aPresContext,
+                              nsISpaceManager* aSpaceManager);
+
 protected:
   nsBlockFrame();
   virtual ~nsBlockFrame();
@@ -166,10 +166,6 @@ protected:
                  nsISpaceManager* aSpaceManager,
                  nsLineBox* aLine, nscoord aDY);
 
-  void SlideFloaters(nsIPresContext* aPresContext,
-                     nsISpaceManager* aSpaceManager,
-                     nsLineBox* aLine, nscoord aDY);
-
   PRBool DrainOverflowLines();
 
   virtual PRIntn GetSkipSides() const;
@@ -228,10 +224,6 @@ protected:
                       PRBool* aKeepReflowGoing,
                       PRBool aDamageDirtyArea = PR_FALSE);
 
-  virtual void DidReflowLine(nsBlockReflowState& aState,
-                             nsLineBox* aLine,
-                             PRBool aKeepReflowGoing);
-
   nsresult PlaceLine(nsBlockReflowState& aState,
                      nsLineLayout& aLineLayout,
                      nsLineBox* aLine,
@@ -249,8 +241,6 @@ protected:
   // XXX where to go
   PRBool ShouldJustifyLine(nsBlockReflowState& aState, nsLineBox* aLine);
 
-  void FindFloaters(nsLineBox* aLine);
-
   void DeleteLine(nsBlockReflowState& aState, nsLineBox* aLine);
 
   //----------------------------------------
@@ -339,6 +329,7 @@ protected:
 
   void PropogateReflowDamage(nsBlockReflowState& aState,
                              nsLineBox* aLine,
+                             const nsRect& aOldCombinedArea,
                              nscoord aDeltaY);
 
   nsresult ComputeTextRuns(nsIPresContext* aPresContext);

layout/html/base/src/nsLineBox.cpp

@@ -27,7 +27,6 @@ nsLineBox::nsLineBox(nsIFrame* aFrame, PRInt32 aCount, PRUint16 flags)
   mFirstChild = aFrame;
   mChildCount = aCount;
   mState = LINE_IS_DIRTY | flags;
-  mFloaters = nsnull;
   mNext = nsnull;
   mBounds.SetRect(0,0,0,0);
   mCombinedArea.SetRect(0,0,0,0);
@@ -39,19 +38,16 @@ nsLineBox::nsLineBox(nsIFrame* aFrame, PRInt32 aCount, PRUint16 flags)
 
 nsLineBox::~nsLineBox()
 {
-  if (nsnull != mFloaters) {
-    delete mFloaters;
-  }
 }
 
 static void
-ListFloaters(FILE* out, PRInt32 aIndent, nsVoidArray* aFloaters)
+ListFloaters(FILE* out, PRInt32 aIndent, const nsFloaterCacheList& aFloaters)
 {
   nsAutoString frameName;
-  PRInt32 j, i, n = aFloaters->Count();
-  for (i = 0; i < n; i++) {
-    for (j = aIndent; --j >= 0; ) fputs("  ", out);
-    nsPlaceholderFrame* ph = (nsPlaceholderFrame*) aFloaters->ElementAt(i);
+  nsFloaterCache* fc = aFloaters.Head();
+  while (fc) {
+    nsFrame::IndentBy(out, aIndent);
+    nsPlaceholderFrame* ph = fc->mPlaceholder;
     if (nsnull != ph) {
       fprintf(out, "placeholder@%p ", ph);
       nsIFrame* frame = ph->GetOutOfFlowFrame();
@@ -59,8 +55,13 @@ ListFloaters(FILE* out, PRInt32 aIndent, nsVoidArray* aFloaters)
         frame->GetFrameName(frameName);
         fputs(frameName, out);
       }
+      fprintf(out, " %s region={%d,%d,%d,%d}",
+              fc->mIsCurrentLineFloater ? "cl" : "bcl",
+              fc->mRegion.x, fc->mRegion.y,
+              fc->mRegion.width, fc->mRegion.height);
       fprintf(out, "\n");
     }
+    fc = fc->Next();
   }
 }
 
@@ -105,7 +106,7 @@ nsLineBox::List(FILE* out, PRInt32 aIndent) const
   }
 
   for (i = aIndent; --i >= 0; ) fputs("  ", out);
-  if (nsnull != mFloaters) {
+  if (mFloaters.NotEmpty()) {
     fputs("> floaters <\n", out);
     ListFloaters(out, aIndent + 1, mFloaters);
     for (i = aIndent; --i >= 0; ) fputs("  ", out);
@@ -463,3 +464,128 @@ nsLineIterator::FindFrameAt(PRInt32 aLineNumber,
   *aFrameFound = frame;
   return NS_OK;
 }
+
+//----------------------------------------------------------------------
+
+nsFloaterCacheList::~nsFloaterCacheList()
+{
+  nsFloaterCache* floater = mHead;
+  while (floater) {
+    nsFloaterCache* next = floater->mNext;
+    delete floater;
+    floater = next;
+  }
+}
+
+nsFloaterCache*
+nsFloaterCacheList::Tail() const
+{
+  nsFloaterCache* fc = mHead;
+  while (fc) {
+    if (!fc->mNext) {
+      break;
+    }
+    fc = fc->mNext;
+  }
+  return fc;
+}
+
+void
+nsFloaterCacheList::Append(nsFloaterCacheFreeList& aList)
+{
+  nsFloaterCache* tail = Tail();
+  if (tail) {
+    tail->mNext = aList.mHead;
+  }
+  else {
+    mHead = aList.mHead;
+  }
+  aList.mHead = nsnull;
+  aList.mTail = nsnull;
+}
+
+nsFloaterCache*
+nsFloaterCacheList::Find(nsIFrame* aOutOfFlowFrame)
+{
+  nsFloaterCache* fc = mHead;
+  while (fc) {
+    if (fc->mPlaceholder->GetOutOfFlowFrame() == aOutOfFlowFrame) {
+      break;
+    }
+    fc = fc->Next();
+  }
+  return fc;
+}
+
+void
+nsFloaterCacheList::Remove(nsFloaterCache* aElement)
+{
+  nsFloaterCache** fcp = &mHead;
+  nsFloaterCache* fc;
+  while (nsnull != (fc = *fcp)) {
+    if (fc == aElement) {
+      *fcp = fc->mNext;
+      break;
+    }
+    fcp = &fc->mNext;
+  }
+}
+
+//----------------------------------------------------------------------
+
+void
+nsFloaterCacheFreeList::Append(nsFloaterCacheList& aList)
+{
+  if (mTail) {
+    mTail->mNext = aList.mHead;
+  }
+  else {
+    mHead = aList.mHead;
+  }
+  mTail = aList.Tail();
+  aList.mHead = nsnull;
+}
+
+nsFloaterCache*
+nsFloaterCacheFreeList::Alloc()
+{
+  nsFloaterCache* fc = mHead;
+  if (mHead) {
+    if (mHead == mTail) {
+      mHead = mTail = nsnull;
+    }
+    else {
+      mHead = fc->mNext;
+    }
+    fc->mNext = nsnull;
+  }
+  else {
+    fc = new nsFloaterCache();
+  }
+  return fc;
+}
+
+void
+nsFloaterCacheFreeList::Append(nsFloaterCache* aFloater)
+{
+  aFloater->mNext = nsnull;
+  if (mTail) {
+    mTail->mNext = aFloater;
+    mTail = aFloater;
+  }
+  else {
+    mHead = mTail = aFloater;
+  }
+}
+
+//----------------------------------------------------------------------
+
+nsFloaterCache::nsFloaterCache()
+  : mPlaceholder(nsnull),
+    mIsCurrentLineFloater(PR_TRUE),
+    mMargins(0, 0, 0, 0),
+    mOffsets(0, 0, 0, 0),
+    mCombinedArea(0, 0, 0, 0),
+    mNext(nsnull)
+{
+}

layout/html/base/src/nsLineBox.h

@@ -24,16 +24,117 @@
 #include "nsILineIterator.h"
 
 // bits in nsLineBox.mState
-#define LINE_IS_DIRTY                 0x1
-#define LINE_IS_BLOCK                 0x2
+#define LINE_IS_DIRTY               0x1
+#define LINE_IS_BLOCK               0x2
+#define LINE_IS_IMPACTED_BY_FLOATER 0x4
 #ifdef BLOCK_DOES_FIRST_LINE
-#define LINE_IS_FIRST_LINE            0x4
+#define LINE_IS_FIRST_LINE          0x8
 #endif
-#define LINE_WAS_DIRTY                0x8
+#define LINE_WAS_DIRTY              0x10
 
 class nsISpaceManager;
 class nsLineBox;
 
+//----------------------------------------------------------------------
+
+class nsFloaterCache;
+class nsFloaterCacheList;
+class nsFloaterCacheFreeList;
+
+// State cached after reflowing a floater. This state is used during
+// incremental reflow when we avoid reflowing a floater.
+class nsFloaterCache {
+public:
+  nsFloaterCache();
+  ~nsFloaterCache() { }
+
+  nsFloaterCache* Next() const { return mNext; }
+
+  nsPlaceholderFrame* mPlaceholder;     // nsPlaceholderFrame
+
+  // This will be true if the floater was placed on the current line
+  // instead of below the current line.
+  PRBool mIsCurrentLineFloater;
+
+  nsMargin mMargins;                    // computed margins
+
+  nsMargin mOffsets;                    // computed offsets (relative pos)
+
+  // Region in the spacemanager impacted by this floater; the
+  // coordinates are relative to the containing block frame. The
+  // region includes the margins around the floater, but doesn't
+  // include the relative offsets.
+  nsRect mRegion;
+
+  // Combined area for the floater. This will not include the margins
+  // for the floater. Like mRegion, the coordinates are relative to
+  // the containing block frame.
+  nsRect mCombinedArea;
+
+protected:
+  nsFloaterCache* mNext;
+
+  friend class nsFloaterCacheList;
+  friend class nsFloaterCacheFreeList;
+};
+
+//----------------------------------------
+
+class nsFloaterCacheList {
+public:
+  nsFloaterCacheList() : mHead(nsnull) { }
+  ~nsFloaterCacheList();
+
+  PRBool IsEmpty() const {
+    return nsnull == mHead;
+  }
+
+  PRBool NotEmpty() const {
+    return nsnull != mHead;
+  }
+
+  nsFloaterCache* Head() const {
+    return mHead;
+  }
+
+  nsFloaterCache* Tail() const;
+
+  nsFloaterCache* Find(nsIFrame* aOutOfFlowFrame);
+
+  void Remove(nsFloaterCache* aElement);
+
+  void Append(nsFloaterCacheFreeList& aList);
+
+protected:
+  nsFloaterCache* mHead;
+
+  friend class nsFloaterCacheFreeList;
+};
+
+//---------------------------------------
+
+class nsFloaterCacheFreeList : public nsFloaterCacheList {
+public:
+  nsFloaterCacheFreeList() : mTail(nsnull) { }
+  ~nsFloaterCacheFreeList() { }
+
+  // Steal away aList's nsFloaterCache objects and put them on this
+  // free-list.
+  void Append(nsFloaterCacheList& aList);
+
+  void Append(nsFloaterCache* aFloaterCache);
+
+  // Allocate a new nsFloaterCache object
+  nsFloaterCache* Alloc();
+
+protected:
+  nsFloaterCache* mTail;
+
+  friend class nsFloaterCacheList;
+};
+
+//----------------------------------------------------------------------
+
 /**
  * The nsLineBox class represents a horizontal line of frames. It contains
  * enough state to support incremental reflow of the frames, event handling
@@ -92,6 +193,19 @@ public:
     }
   }
 
+  void SetLineIsImpactedByFloater(PRBool aValue) {
+    if (aValue) {
+      mState |= LINE_IS_IMPACTED_BY_FLOATER;
+    }
+    else {
+      mState &= ~LINE_IS_IMPACTED_BY_FLOATER;
+    }
+  }
+
+  PRBool IsImpactedByFloater() const {
+    return 0 != (LINE_IS_IMPACTED_BY_FLOATER & mState);
+  }
+
 #ifdef BLOCK_DOES_FIRST_LINE
   PRBool IsFirstLine() const {
     return 0 != (LINE_IS_FIRST_LINE & mState);
@@ -150,7 +264,7 @@ public:
   nsRect mBounds;
   nsRect mCombinedArea;
   nscoord mCarriedOutBottomMargin;/* XXX switch to 16 bits */
-  nsVoidArray* mFloaters;
+  nsFloaterCacheList mFloaters;
   nsLineBox* mNext;
   nscoord mMaxElementWidth;  // width part of max-element-size
 };