Add m-esr52 at 52.6.0

1 files changed, 1038 insertions, 0 deletions

diff --git a/layout/generic/nsBlockFrame.h b/layout/generic/nsBlockFrame.h
new file mode 100644
index 000000000..bb41a6e99
--- /dev/null
+++ b/layout/generic/nsBlockFrame.h
@@ -0,0 +1,1038 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+// vim:cindent:ts=2:et:sw=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/. */
+
+/*
+ * rendering object for CSS display:block, inline-block, and list-item
+ * boxes, also used for various anonymous boxes
+ */
+
+#ifndef nsBlockFrame_h___
+#define nsBlockFrame_h___
+
+#include "nsContainerFrame.h"
+#include "nsHTMLParts.h"
+#include "nsLineBox.h"
+#include "nsCSSPseudoElements.h"
+#include "nsFloatManager.h"
+
+enum class LineReflowStatus {
+  // The line was completely reflowed and fit in available width, and we should
+  // try to pull up content from the next line if possible.
+  OK,
+  // The line was completely reflowed and fit in available width, but we should
+  // not try to pull up content from the next line.
+  Stop,
+  // We need to reflow the line again at its current vertical position. The
+  // new reflow should not try to pull up any frames from the next line.
+  RedoNoPull,
+  // We need to reflow the line again using the floats from its height
+  // this reflow, since its height made it hit floats that were not
+  // adjacent to its top.
+  RedoMoreFloats,
+  // We need to reflow the line again at a lower vertical postion where there
+  // may be more horizontal space due to different float configuration.
+  RedoNextBand,
+  // The line did not fit in the available vertical space. Try pushing it to
+  // the next page or column if it's not the first line on the current page/column.
+  Truncated
+};
+
+class nsBlockInFlowLineIterator;
+class nsBulletFrame;
+namespace mozilla {
+class BlockReflowInput;
+} // namespace mozilla
+
+/**
+ * Some invariants:
+ * -- The overflow out-of-flows list contains the out-of-
+ * flow frames whose placeholders are in the overflow list.
+ * -- A given piece of content has at most one placeholder
+ * frame in a block's normal child list.
+ * -- While a block is being reflowed, and from then until
+ * its next-in-flow is reflowed it may have a
+ * PushedFloatProperty frame property that points to
+ * an nsFrameList. This list contains continuations for
+ * floats whose prev-in-flow is in the block's regular float
+ * list and first-in-flows of floats that did not fit, but
+ * whose placeholders are in the block or one of its
+ * prev-in-flows.
+ * -- In all these frame lists, if there are two frames for
+ * the same content appearing in the list, then the frames
+ * appear with the prev-in-flow before the next-in-flow.
+ * -- While reflowing a block, its overflow line list
+ * will usually be empty but in some cases will have lines
+ * (while we reflow the block at its shrink-wrap width).
+ * In this case any new overflowing content must be
+ * prepended to the overflow lines.
+ */
+
+/*
+ * Base class for block and inline frames.
+ * The block frame has an additional child list, kAbsoluteList, which
+ * contains the absolutely positioned frames.
+ */
+class nsBlockFrame : public nsContainerFrame
+{
+  using BlockReflowInput = mozilla::BlockReflowInput;
+
+public:
+  NS_DECL_QUERYFRAME_TARGET(nsBlockFrame)
+  NS_DECL_FRAMEARENA_HELPERS
+
+  typedef nsLineList::iterator LineIterator;
+  typedef nsLineList::const_iterator ConstLineIterator;
+  typedef nsLineList::reverse_iterator ReverseLineIterator;
+  typedef nsLineList::const_reverse_iterator ConstReverseLineIterator;
+
+  LineIterator LinesBegin() { return mLines.begin(); }
+  LineIterator LinesEnd() { return mLines.end(); }
+  ConstLineIterator LinesBegin() const { return mLines.begin(); }
+  ConstLineIterator LinesEnd() const { return mLines.end(); }
+  ReverseLineIterator LinesRBegin() { return mLines.rbegin(); }
+  ReverseLineIterator LinesREnd() { return mLines.rend(); }
+  ConstReverseLineIterator LinesRBegin() const { return mLines.rbegin(); }
+  ConstReverseLineIterator LinesREnd() const { return mLines.rend(); }
+  LineIterator LinesBeginFrom(nsLineBox* aList) { return mLines.begin(aList); }
+  ReverseLineIterator LinesRBeginFrom(nsLineBox* aList) { return mLines.rbegin(aList); }
+
+  friend nsBlockFrame* NS_NewBlockFrame(nsIPresShell* aPresShell,
+                                        nsStyleContext* aContext);
+
+  // nsQueryFrame
+  NS_DECL_QUERYFRAME
+
+  // nsIFrame
+  virtual void Init(nsIContent* aContent,
+                    nsContainerFrame* aParent,
+                    nsIFrame* aPrevInFlow) override;
+  virtual void SetInitialChildList(ChildListID aListID,
+                                   nsFrameList& aChildList) override;
+  virtual void AppendFrames(ChildListID aListID,
+                            nsFrameList& aFrameList) override;
+  virtual void InsertFrames(ChildListID aListID,
+                            nsIFrame* aPrevFrame,
+                            nsFrameList& aFrameList) override;
+  virtual void RemoveFrame(ChildListID aListID,
+                           nsIFrame* aOldFrame) override;
+  virtual const nsFrameList& GetChildList(ChildListID aListID) const override;
+  virtual void GetChildLists(nsTArray<ChildList>* aLists) const override;
+  virtual nscoord GetLogicalBaseline(mozilla::WritingMode aWritingMode) const override;
+  bool GetVerticalAlignBaseline(mozilla::WritingMode aWM,
+                                nscoord* aBaseline) const override
+  {
+    nscoord lastBaseline;
+    if (GetNaturalBaselineBOffset(aWM, BaselineSharingGroup::eLast, &lastBaseline)) {
+      *aBaseline = BSize() - lastBaseline;
+      return true;
+    }
+    return false;
+  }
+  bool GetNaturalBaselineBOffset(mozilla::WritingMode aWM,
+                                 BaselineSharingGroup aBaselineGroup,
+                                 nscoord*             aBaseline) const override;
+  virtual nscoord GetCaretBaseline() const override;
+  virtual void DestroyFrom(nsIFrame* aDestructRoot) override;
+  virtual nsSplittableType GetSplittableType() const override;
+  virtual bool IsFloatContainingBlock() const override;
+  virtual void BuildDisplayList(nsDisplayListBuilder* aBuilder,
+                                const nsRect& aDirtyRect,
+                                const nsDisplayListSet& aLists) override;
+  virtual nsIAtom* GetType() const override;
+  virtual bool IsFrameOfType(uint32_t aFlags) const override
+  {
+    return nsContainerFrame::IsFrameOfType(aFlags &
+             ~(nsIFrame::eCanContainOverflowContainers |
+               nsIFrame::eBlockFrame));
+  }
+
+  virtual void InvalidateFrame(uint32_t aDisplayItemKey = 0) override;
+  virtual void InvalidateFrameWithRect(const nsRect& aRect, uint32_t aDisplayItemKey = 0) override;
+
+#ifdef DEBUG_FRAME_DUMP
+  void List(FILE* out = stderr, const char* aPrefix = "", uint32_t aFlags = 0) const override;
+  virtual nsresult GetFrameName(nsAString& aResult) const override;
+#endif
+
+#ifdef DEBUG
+  virtual nsFrameState GetDebugStateBits() const override;
+  const char* LineReflowStatusToString(LineReflowStatus aLineReflowStatus) const;
+#endif
+
+#ifdef ACCESSIBILITY
+  virtual mozilla::a11y::AccType AccessibleType() override;
+#endif
+
+  // Line cursor methods to speed up line searching in which one query
+  // result is expected to be close to the next in general. This is
+  // mainly for searching line(s) containing a point. It is also used
+  // as a cache for local computation. Use AutoLineCursorSetup for the
+  // latter case so that it wouldn't interact unexpectedly with the
+  // former. The basic idea for the former is that we set the cursor
+  // property if the lines' overflowArea.VisualOverflow().ys and
+  // overflowArea.VisualOverflow().yMosts are non-decreasing
+  // (considering only non-empty overflowArea.VisualOverflow()s; empty
+  // overflowArea.VisualOverflow()s never participate in event handling
+  // or painting), and the block has sufficient number of lines. The
+  // cursor property points to a "recently used" line. If we get a
+  // series of requests that work on lines
+  // "near" the cursor, then we can find those nearby lines quickly by
+  // starting our search at the cursor.
+
+  // Clear out line cursor because we're disturbing the lines (i.e., Reflow)
+  void ClearLineCursor();
+  // Get the first line that might contain y-coord 'y', or nullptr if you must search
+  // all lines. If nonnull is returned then we guarantee that the lines'
+  // combinedArea.ys and combinedArea.yMosts are non-decreasing.
+  // The actual line returned might not contain 'y', but if not, it is guaranteed
+  // to be before any line which does contain 'y'.
+  nsLineBox* GetFirstLineContaining(nscoord y);
+  // Set the line cursor to our first line. Only call this if you
+  // guarantee that either the lines' combinedArea.ys and combinedArea.
+  // yMosts are non-decreasing, or the line cursor is cleared before
+  // building the display list of this frame.
+  void SetupLineCursor();
+
+  /**
+   * Helper RAII class for automatically set and clear line cursor for
+   * temporary use. If the frame already has line cursor, this would be
+   * a no-op.
+   */
+  class MOZ_STACK_CLASS AutoLineCursorSetup
+  {
+  public:
+    explicit AutoLineCursorSetup(nsBlockFrame* aFrame)
+      : mFrame(aFrame)
+      , mOrigCursor(aFrame->GetLineCursor())
+    {
+      if (!mOrigCursor) {
+        mFrame->SetupLineCursor();
+      }
+    }
+    ~AutoLineCursorSetup()
+    {
+      if (mOrigCursor) {
+        mFrame->Properties().Set(LineCursorProperty(), mOrigCursor);
+      } else {
+        mFrame->ClearLineCursor();
+      }
+    }
+
+  private:
+    nsBlockFrame* mFrame;
+    nsLineBox* mOrigCursor;
+  };
+
+  virtual void ChildIsDirty(nsIFrame* aChild) override;
+  virtual bool IsVisibleInSelection(nsISelection* aSelection) override;
+
+  virtual bool IsEmpty() override;
+  virtual bool CachedIsEmpty() override;
+  virtual bool IsSelfEmpty() override;
+
+  // Given that we have a bullet, does it actually draw something, i.e.,
+  // do we have either a 'list-style-type' or 'list-style-image' that is
+  // not 'none'?
+  bool BulletIsEmpty() const;
+
+  /**
+   * Return the bullet text equivalent.
+   */
+  void GetSpokenBulletText(nsAString& aText) const;
+
+  /**
+   * Return true if there's a bullet.
+   */
+  bool HasBullet() const {
+    return HasOutsideBullet() || HasInsideBullet();
+  }
+
+  /**
+   * @return true if this frame has an inside bullet frame.
+   */
+  bool HasInsideBullet() const {
+    return 0 != (mState & NS_BLOCK_FRAME_HAS_INSIDE_BULLET);
+  }
+
+  /**
+   * @return true if this frame has an outside bullet frame.
+   */
+  bool HasOutsideBullet() const {
+    return 0 != (mState & NS_BLOCK_FRAME_HAS_OUTSIDE_BULLET);
+  }
+
+  /**
+   * @return the bullet frame or nullptr if we don't have one.
+   */
+  nsBulletFrame* GetBullet() const {
+    nsBulletFrame* outside = GetOutsideBullet();
+    return outside ? outside : GetInsideBullet();
+  }
+
+  virtual void MarkIntrinsicISizesDirty() override;
+private:
+  void CheckIntrinsicCacheAgainstShrinkWrapState();
+public:
+  virtual nscoord GetMinISize(nsRenderingContext *aRenderingContext) override;
+  virtual nscoord GetPrefISize(nsRenderingContext *aRenderingContext) override;
+
+  virtual nsRect ComputeTightBounds(DrawTarget* aDrawTarget) const override;
+
+  virtual nsresult GetPrefWidthTightBounds(nsRenderingContext* aContext,
+                                           nscoord* aX,
+                                           nscoord* aXMost) override;
+
+  /**
+   * Compute the final block size of this frame.
+   *
+   * @param aReflowInput Data structure passed from parent during reflow.
+   * @param aReflowStatus A pointer to the reflow status for when we're finished
+   *        doing reflow. this will get set appropriately if the block-size
+   *        causes us to exceed the current available (page) block-size.
+   * @param aContentBSize The block-size of content, precomputed outside of this
+   *        function. The final block-size that is used in aMetrics will be set
+   *        to either this or the available block-size, whichever is larger, in
+   *        the case where our available block-size is constrained, and we
+   *        overflow that available block-size.
+   * @param aBorderPadding The margins representing the border padding for block
+   *        frames. Can be 0.
+   * @param aFinalSize Out parameter for final block-size.
+   * @param aConsumed The block-size already consumed by our previous-in-flows.
+   */
+  void ComputeFinalBSize(const ReflowInput& aReflowInput,
+                         nsReflowStatus* aStatus,
+                         nscoord aContentBSize,
+                         const mozilla::LogicalMargin& aBorderPadding,
+                         mozilla::LogicalSize& aFinalSize,
+                         nscoord aConsumed);
+
+  virtual void Reflow(nsPresContext* aPresContext,
+                      ReflowOutput& aDesiredSize,
+                      const ReflowInput& aReflowInput,
+                      nsReflowStatus& aStatus) override;
+
+  virtual nsresult AttributeChanged(int32_t aNameSpaceID,
+                                    nsIAtom* aAttribute,
+                                    int32_t aModType) override;
+
+  /**
+   * Move any frames on our overflow list to the end of our principal list.
+   * @return true if there were any overflow frames
+   */
+  virtual bool DrainSelfOverflowList() override;
+
+  virtual nsresult StealFrame(nsIFrame* aChild) override;
+
+  virtual void DeleteNextInFlowChild(nsIFrame* aNextInFlow,
+                                     bool aDeletingEmptyFrames) override;
+
+  /**
+    * This is a special method that allows a child class of nsBlockFrame to
+    * return a special, customized nsStyleText object to the nsLineLayout
+    * constructor. It is used when the nsBlockFrame child needs to specify its
+    * custom rendering style.
+    */
+  virtual const nsStyleText* StyleTextForLineLayout();
+
+  /**
+   * Determines whether the collapsed margin carried out of the last
+   * line includes the margin-top of a line with clearance (in which
+   * case we must avoid collapsing that margin with our bottom margin)
+   */
+  bool CheckForCollapsedBEndMarginFromClearanceLine();
+
+  static nsresult GetCurrentLine(BlockReflowInput *aState, nsLineBox **aOutCurrentLine);
+
+  /**
+   * Determine if this block is a margin root at the top/bottom edges.
+   */
+  void IsMarginRoot(bool* aBStartMarginRoot, bool* aBEndMarginRoot);
+
+  static bool BlockNeedsFloatManager(nsIFrame* aBlock);
+
+  /**
+   * Returns whether aFrame is a block frame that will wrap its contents
+   * around floats intruding on it from the outside.  (aFrame need not
+   * be a block frame, but if it's not, the result will be false.)
+   */
+  static bool BlockCanIntersectFloats(nsIFrame* aFrame);
+
+  /**
+   * Returns the inline size that needs to be cleared past floats for
+   * blocks that cannot intersect floats.  aState must already have
+   * GetAvailableSpace called on it for the block-dir position that we
+   * care about (which need not be its current mBCoord)
+   */
+  struct ReplacedElementISizeToClear {
+    // Note that we care about the inline-start margin but can ignore
+    // the inline-end margin.
+    nscoord marginIStart, borderBoxISize;
+  };
+  static ReplacedElementISizeToClear
+    ISizeToClearPastFloats(const BlockReflowInput& aState,
+                           const mozilla::LogicalRect& aFloatAvailableSpace,
+                           nsIFrame* aFrame);
+
+  /**
+   * Creates a contination for aFloat and adds it to the list of overflow floats.
+   * Also updates aState.mReflowStatus to include the float's incompleteness.
+   * Must only be called while this block frame is in reflow.
+   * aFloatStatus must be the float's true, unmodified reflow status.
+   */
+  nsresult SplitFloat(BlockReflowInput& aState,
+                      nsIFrame* aFloat,
+                      nsReflowStatus aFloatStatus);
+
+  /**
+   * Walks up the frame tree, starting with aCandidate, and returns the first
+   * block frame that it encounters.
+   */
+  static nsBlockFrame* GetNearestAncestorBlock(nsIFrame* aCandidate);
+
+  struct FrameLines {
+    nsLineList mLines;
+    nsFrameList mFrames;
+  };
+
+protected:
+  explicit nsBlockFrame(nsStyleContext* aContext)
+    : nsContainerFrame(aContext)
+    , mMinWidth(NS_INTRINSIC_WIDTH_UNKNOWN)
+    , mPrefWidth(NS_INTRINSIC_WIDTH_UNKNOWN)
+  {
+#ifdef DEBUG
+  InitDebugFlags();
+#endif
+  }
+  virtual ~nsBlockFrame();
+
+#ifdef DEBUG
+  already_AddRefed<nsStyleContext> GetFirstLetterStyle(nsPresContext* aPresContext);
+#endif
+
+  NS_DECLARE_FRAME_PROPERTY_WITHOUT_DTOR(LineCursorProperty, nsLineBox)
+  bool HasLineCursor() { return GetStateBits() & NS_BLOCK_HAS_LINE_CURSOR; }
+  nsLineBox* GetLineCursor() {
+    return HasLineCursor() ? Properties().Get(LineCursorProperty()) : nullptr;
+  }
+
+  nsLineBox* NewLineBox(nsIFrame* aFrame, bool aIsBlock) {
+    return NS_NewLineBox(PresContext()->PresShell(), aFrame, aIsBlock);
+  }
+  nsLineBox* NewLineBox(nsLineBox* aFromLine, nsIFrame* aFrame, int32_t aCount) {
+    return NS_NewLineBox(PresContext()->PresShell(), aFromLine, aFrame, aCount);
+  }
+  void FreeLineBox(nsLineBox* aLine) {
+    if (aLine == GetLineCursor()) {
+      ClearLineCursor();
+    }
+    aLine->Destroy(PresContext()->PresShell());
+  }
+  /**
+   * Helper method for StealFrame.
+   */
+  void RemoveFrameFromLine(nsIFrame* aChild, nsLineList::iterator aLine,
+                           nsFrameList& aFrameList, nsLineList& aLineList);
+
+  void TryAllLines(nsLineList::iterator* aIterator,
+                   nsLineList::iterator* aStartIterator,
+                   nsLineList::iterator* aEndIterator,
+                   bool* aInOverflowLines,
+                   FrameLines** aOverflowLines);
+
+  /** move the frames contained by aLine by aDeltaBCoord
+    * if aLine is a block, its child floats are added to the state manager
+    */
+  void SlideLine(BlockReflowInput& aState,
+                 nsLineBox* aLine, nscoord aDeltaBCoord);
+
+  void UpdateLineContainerSize(nsLineBox* aLine,
+                               const nsSize& aNewContainerSize);
+
+  // helper for SlideLine and UpdateLineContainerSize
+  void MoveChildFramesOfLine(nsLineBox* aLine, nscoord aDeltaBCoord);
+
+  void ComputeFinalSize(const ReflowInput& aReflowInput,
+                        BlockReflowInput& aState,
+                        ReflowOutput& aMetrics,
+                        nscoord* aBottomEdgeOfChildren);
+
+  void ComputeOverflowAreas(const nsRect& aBounds,
+                            const nsStyleDisplay* aDisplay,
+                            nscoord aBottomEdgeOfChildren,
+                            nsOverflowAreas& aOverflowAreas);
+
+  /**
+   * Add the frames in aFrameList to this block after aPrevSibling.
+   * This block thinks in terms of lines, but the frame construction code
+   * knows nothing about lines at all so we need to find the line that
+   * contains aPrevSibling and add aFrameList after aPrevSibling on that line.
+   * New lines are created as necessary to handle block data in aFrameList.
+   * This function will clear aFrameList.
+   */
+  void AddFrames(nsFrameList& aFrameList, nsIFrame* aPrevSibling);
+
+  /**
+   * Perform Bidi resolution on this frame
+   */
+  nsresult ResolveBidi();
+
+  /**
+   * Test whether the frame is a form control in a visual Bidi page.
+   * This is necessary for backwards-compatibility, because most visual
+   * pages use logical order for form controls so that they will
+   * display correctly on native widgets in OSs with Bidi support
+   * @param aPresContext the pres context
+   * @return whether the frame is a BIDI form control
+   */
+  bool IsVisualFormControl(nsPresContext* aPresContext);
+
+  /**
+   * Helper function to create bullet frame.
+   * @param aCreateBulletList true to create bullet list; otherwise number list.
+   * @param aListStylePositionInside true to put the list position inside;
+   * otherwise outside.
+   */
+  void CreateBulletFrameForListItem(bool aCreateBulletList,
+                                    bool aListStylePositionInside);
+
+public:
+  /**
+   * Does all the real work for removing aDeletedFrame
+   * -- finds the line containing aDeletedFrame
+   * -- removes all aDeletedFrame next-in-flows (or all continuations,
+   * if REMOVE_FIXED_CONTINUATIONS is given)
+   * -- marks lines dirty as needed
+   * -- marks textruns dirty (unless FRAMES_ARE_EMPTY is given, in which
+   * case textruns do not need to be dirtied)
+   * -- destroys all removed frames
+   */
+  enum {
+    REMOVE_FIXED_CONTINUATIONS = 0x02,
+    FRAMES_ARE_EMPTY = 0x04
+  };
+  void DoRemoveFrame(nsIFrame* aDeletedFrame, uint32_t aFlags);
+
+  void ReparentFloats(nsIFrame* aFirstFrame, nsBlockFrame* aOldParent,
+                      bool aReparentSiblings);
+
+  virtual bool ComputeCustomOverflow(nsOverflowAreas& aOverflowAreas) override;
+
+  virtual void UnionChildOverflow(nsOverflowAreas& aOverflowAreas) override;
+
+  /** Load all of aFrame's floats into the float manager iff aFrame is not a
+   *  block formatting context. Handles all necessary float manager translations;
+   *  assumes float manager is in aFrame's parent's coord system.
+   *  Safe to call on non-blocks (does nothing).
+   */
+  static void RecoverFloatsFor(nsIFrame* aFrame,
+                               nsFloatManager& aFloatManager,
+                               mozilla::WritingMode aWM,
+                               const nsSize& aContainerSize);
+
+  /**
+   * Determine if we have any pushed floats from a previous continuation.
+   *
+   * @returns true, if any of the floats at the beginning of our mFloats list
+   *          have the NS_FRAME_IS_PUSHED_FLOAT bit set; false otherwise.
+   */
+  bool HasPushedFloatsFromPrevContinuation() const {
+    if (!mFloats.IsEmpty()) {
+      // If we have pushed floats, then they should be at the beginning of our
+      // float list.
+      if (mFloats.FirstChild()->GetStateBits() & NS_FRAME_IS_PUSHED_FLOAT) {
+        return true;
+      }
+    }
+
+#ifdef DEBUG
+    // Double-check the above assertion that pushed floats should be at the
+    // beginning of our floats list.
+    for (nsFrameList::Enumerator e(mFloats); !e.AtEnd(); e.Next()) {
+      nsIFrame* f = e.get();
+      NS_ASSERTION(!(f->GetStateBits() & NS_FRAME_IS_PUSHED_FLOAT),
+        "pushed floats must be at the beginning of the float list");
+    }
+#endif
+    return false;
+  }
+
+  virtual bool RenumberChildFrames(int32_t* aOrdinal,
+                                   int32_t aDepth,
+                                   int32_t aIncrement,
+                                   bool aForCounting) override;
+protected:
+
+  /** grab overflow lines from this block's prevInFlow, and make them
+    * part of this block's mLines list.
+    * @return true if any lines were drained.
+    */
+  bool DrainOverflowLines();
+
+  /**
+   * @return false iff this block does not have a float on any child list.
+   * This function is O(1).
+   */
+  bool MaybeHasFloats() const {
+    if (!mFloats.IsEmpty()) {
+      return true;
+    }
+    // XXX this could be replaced with HasPushedFloats() if we enforced
+    // removing the property when the frame list becomes empty.
+    nsFrameList* list = GetPushedFloats();
+    if (list && !list->IsEmpty()) {
+      return true;
+    }
+    // For the OverflowOutOfFlowsProperty I think we do enforce that, but it's
+    // a mix of out-of-flow frames, so that's why the method name has "Maybe".
+    return GetStateBits() & NS_BLOCK_HAS_OVERFLOW_OUT_OF_FLOWS;
+  }
+
+  /**
+   * Moves frames from our PushedFloats list back into our mFloats list.
+   */
+  void DrainSelfPushedFloats();
+
+  /**
+   * First calls DrainSelfPushedFloats() then grabs pushed floats from this
+   * block's prev-in-flow, and splice them into this block's mFloats list too.
+   */
+  void DrainPushedFloats();
+
+  /** Load all our floats into the float manager (without reflowing them).
+   *  Assumes float manager is in our own coordinate system.
+   */
+  void RecoverFloats(nsFloatManager& aFloatManager,
+                     mozilla::WritingMode aWM,
+                     const nsSize& aContainerSize);
+
+  /** Reflow pushed floats
+   */
+  void ReflowPushedFloats(BlockReflowInput& aState,
+                          nsOverflowAreas& aOverflowAreas,
+                          nsReflowStatus& aStatus);
+
+  /** Find any trailing BR clear from the last line of the block (or its PIFs)
+   */
+  mozilla::StyleClear FindTrailingClear();
+
+  /**
+   * Remove a float from our float list.
+   */
+  void RemoveFloat(nsIFrame* aFloat);
+  /**
+   * Remove a float from the float cache for the line its placeholder is on.
+   */
+  void RemoveFloatFromFloatCache(nsIFrame* aFloat);
+
+  void CollectFloats(nsIFrame* aFrame, nsFrameList& aList,
+                     bool aCollectFromSiblings) {
+    if (MaybeHasFloats()) {
+      DoCollectFloats(aFrame, aList, aCollectFromSiblings);
+    }
+  }
+  void DoCollectFloats(nsIFrame* aFrame, nsFrameList& aList,
+                       bool aCollectFromSiblings);
+
+  // Remove a float, abs, rel positioned frame from the appropriate block's list
+  static void DoRemoveOutOfFlowFrame(nsIFrame* aFrame);
+
+  /** set up the conditions necessary for an resize reflow
+    * the primary task is to mark the minimumly sufficient lines dirty.
+    */
+  void PrepareResizeReflow(BlockReflowInput& aState);
+
+  /** reflow all lines that have been marked dirty */
+  void ReflowDirtyLines(BlockReflowInput& aState);
+
+  /** Mark a given line dirty due to reflow being interrupted on or before it */
+  void MarkLineDirtyForInterrupt(nsLineBox* aLine);
+
+  //----------------------------------------
+  // Methods for line reflow
+  /**
+   * Reflow a line.
+   * @param aState           the current reflow state
+   * @param aLine            the line to reflow.  can contain a single block frame
+   *                         or contain 1 or more inline frames.
+   * @param aKeepReflowGoing [OUT] indicates whether the caller should continue to reflow more lines
+   */
+  void ReflowLine(BlockReflowInput& aState,
+                  LineIterator aLine,
+                  bool* aKeepReflowGoing);
+
+  // Return false if it needs another reflow because of reduced space
+  // between floats that are next to it (but not next to its top), and
+  // return true otherwise.
+  bool PlaceLine(BlockReflowInput& aState,
+                 nsLineLayout& aLineLayout,
+                 LineIterator aLine,
+                 nsFloatManager::SavedState* aFloatStateBeforeLine,
+                 mozilla::LogicalRect& aFloatAvailableSpace, //in-out
+                 nscoord& aAvailableSpaceBSize, // in-out
+                 bool* aKeepReflowGoing);
+
+  /**
+    * If NS_BLOCK_LOOK_FOR_DIRTY_FRAMES is set, call MarkLineDirty
+    * on any line with a child frame that is dirty.
+    */
+  void LazyMarkLinesDirty();
+
+  /**
+   * Mark |aLine| dirty, and, if necessary because of possible
+   * pull-up, mark the previous line dirty as well. Also invalidates textruns
+   * on those lines because the text in the lines might have changed due to
+   * addition/removal of frames.
+   * @param aLine the line to mark dirty
+   * @param aLineList the line list containing that line
+   */
+  void MarkLineDirty(LineIterator aLine, const nsLineList* aLineList);
+
+  // XXX where to go
+  bool IsLastLine(BlockReflowInput& aState,
+                  LineIterator aLine);
+
+  void DeleteLine(BlockReflowInput& aState,
+                  nsLineList::iterator aLine,
+                  nsLineList::iterator aLineEnd);
+
+  //----------------------------------------
+  // Methods for individual frame reflow
+
+  bool ShouldApplyBStartMargin(BlockReflowInput& aState,
+                               nsLineBox* aLine,
+                               nsIFrame* aChildFrame);
+
+  void ReflowBlockFrame(BlockReflowInput& aState,
+                        LineIterator aLine,
+                        bool* aKeepGoing);
+
+  void ReflowInlineFrames(BlockReflowInput& aState,
+                          LineIterator aLine,
+                          bool* aKeepLineGoing);
+
+  void DoReflowInlineFrames(BlockReflowInput& aState,
+                            nsLineLayout& aLineLayout,
+                            LineIterator aLine,
+                            nsFlowAreaRect& aFloatAvailableSpace,
+                            nscoord& aAvailableSpaceBSize,
+                            nsFloatManager::SavedState* aFloatStateBeforeLine,
+                            bool* aKeepReflowGoing,
+                            LineReflowStatus* aLineReflowStatus,
+                            bool aAllowPullUp);
+
+  void ReflowInlineFrame(BlockReflowInput& aState,
+                         nsLineLayout& aLineLayout,
+                         LineIterator aLine,
+                         nsIFrame* aFrame,
+                         LineReflowStatus* aLineReflowStatus);
+
+  // Compute the available inline size for a float.
+  mozilla::LogicalRect AdjustFloatAvailableSpace(
+                         BlockReflowInput& aState,
+                         const mozilla::LogicalRect& aFloatAvailableSpace,
+                         nsIFrame* aFloatFrame);
+  // Computes the border-box inline size of the float
+  nscoord ComputeFloatISize(BlockReflowInput& aState,
+                            const mozilla::LogicalRect& aFloatAvailableSpace,
+                            nsIFrame* aFloat);
+  // An incomplete aReflowStatus indicates the float should be split
+  // but only if the available height is constrained.
+  // aAdjustedAvailableSpace is the result of calling
+  // nsBlockFrame::AdjustFloatAvailableSpace.
+  void ReflowFloat(BlockReflowInput& aState,
+                   const mozilla::LogicalRect& aAdjustedAvailableSpace,
+                   nsIFrame* aFloat,
+                   mozilla::LogicalMargin& aFloatMargin,
+                   mozilla::LogicalMargin& aFloatOffsets,
+                   // Whether the float's position
+                   // (aAdjustedAvailableSpace) has been pushed down
+                   // due to the presence of other floats.
+                   bool aFloatPushedDown,
+                   nsReflowStatus& aReflowStatus);
+
+  //----------------------------------------
+  // Methods for pushing/pulling lines/frames
+
+  /**
+   * Create a next-in-flow, if necessary, for aFrame. If a new frame is
+   * created, place it in aLine if aLine is not null.
+   * @param aState the block reflow state
+   * @param aLine where to put a new frame
+   * @param aFrame the frame
+   * @return true if a new frame was created, false if not
+   */
+  bool CreateContinuationFor(BlockReflowInput& aState,
+                             nsLineBox* aLine,
+                             nsIFrame* aFrame);
+
+  /**
+   * Push aLine (and any after it), since it cannot be placed on this
+   * page/column.  Set aKeepReflowGoing to false and set
+   * flag aState.mReflowStatus as incomplete.
+   */
+  void PushTruncatedLine(BlockReflowInput& aState,
+                         LineIterator aLine,
+                         bool* aKeepReflowGoing);
+
+  void SplitLine(BlockReflowInput& aState,
+                 nsLineLayout& aLineLayout,
+                 LineIterator aLine,
+                 nsIFrame* aFrame,
+                 LineReflowStatus* aLineReflowStatus);
+
+  /**
+   * Pull a frame from the next available location (one of our lines or
+   * one of our next-in-flows lines).
+   * @return the pulled frame or nullptr
+   */
+  nsIFrame* PullFrame(BlockReflowInput& aState,
+                      LineIterator aLine);
+
+  /**
+   * Try to pull a frame out of a line pointed at by aFromLine.
+   *
+   * Note: pulling a frame from a line that is a place-holder frame
+   * doesn't automatically remove the corresponding float from the
+   * line's float array. This happens indirectly: either the line gets
+   * emptied (and destroyed) or the line gets reflowed (because we mark
+   * it dirty) and the code at the top of ReflowLine empties the
+   * array. So eventually, it will be removed, just not right away.
+   *
+   * @return the pulled frame or nullptr
+   */
+  nsIFrame* PullFrameFrom(nsLineBox* aLine,
+                          nsBlockFrame* aFromContainer,
+                          nsLineList::iterator aFromLine);
+
+  /**
+   * Push the line after aLineBefore to the overflow line list.
+   * @param aLineBefore a line in 'mLines' (or LinesBegin() when
+   *        pushing the first line)
+   */
+  void PushLines(BlockReflowInput& aState,
+                 nsLineList::iterator aLineBefore);
+
+  void PropagateFloatDamage(BlockReflowInput& aState,
+                            nsLineBox* aLine,
+                            nscoord aDeltaBCoord);
+
+  void CheckFloats(BlockReflowInput& aState);
+
+  //----------------------------------------
+  // List handling kludge
+
+  void ReflowBullet(nsIFrame* aBulletFrame,
+                    BlockReflowInput& aState,
+                    ReflowOutput& aMetrics,
+                    nscoord aLineTop);
+
+  //----------------------------------------
+
+  virtual nsILineIterator* GetLineIterator() override;
+
+public:
+  bool HasOverflowLines() const {
+    return 0 != (GetStateBits() & NS_BLOCK_HAS_OVERFLOW_LINES);
+  }
+  FrameLines* GetOverflowLines() const;
+protected:
+  FrameLines* RemoveOverflowLines();
+  void SetOverflowLines(FrameLines* aOverflowLines);
+  void DestroyOverflowLines();
+
+  /**
+   * This class is useful for efficiently modifying the out of flow
+   * overflow list. It gives the client direct writable access to
+   * the frame list temporarily but ensures that property is only
+   * written back if absolutely necessary.
+   */
+  struct nsAutoOOFFrameList {
+    nsFrameList mList;
+
+    explicit nsAutoOOFFrameList(nsBlockFrame* aBlock)
+      : mPropValue(aBlock->GetOverflowOutOfFlows())
+      , mBlock(aBlock) {
+      if (mPropValue) {
+        mList = *mPropValue;
+      }
+    }
+    ~nsAutoOOFFrameList() {
+      mBlock->SetOverflowOutOfFlows(mList, mPropValue);
+    }
+  protected:
+    nsFrameList* const mPropValue;
+    nsBlockFrame* const mBlock;
+  };
+  friend struct nsAutoOOFFrameList;
+
+  nsFrameList* GetOverflowOutOfFlows() const;
+  void SetOverflowOutOfFlows(const nsFrameList& aList, nsFrameList* aPropValue);
+
+  /**
+   * @return the inside bullet frame or nullptr if we don't have one.
+   */
+  nsBulletFrame* GetInsideBullet() const;
+
+  /**
+   * @return the outside bullet frame or nullptr if we don't have one.
+   */
+  nsBulletFrame* GetOutsideBullet() const;
+
+  /**
+   * @return the outside bullet frame list frame property.
+   */
+  nsFrameList* GetOutsideBulletList() const;
+
+  /**
+   * @return true if this frame has pushed floats.
+   */
+  bool HasPushedFloats() const {
+    return 0 != (GetStateBits() & NS_BLOCK_HAS_PUSHED_FLOATS);
+  }
+
+  // Get the pushed floats list, which is used for *temporary* storage
+  // of floats during reflow, between when we decide they don't fit in
+  // this block until our next continuation takes them.
+  nsFrameList* GetPushedFloats() const;
+  // Get the pushed floats list, or if there is not currently one,
+  // make a new empty one.
+  nsFrameList* EnsurePushedFloats();
+  // Remove and return the pushed floats list.
+  nsFrameList* RemovePushedFloats();
+
+#ifdef DEBUG
+  void VerifyLines(bool aFinalCheckOK);
+  void VerifyOverflowSituation();
+  int32_t GetDepth() const;
+#endif
+
+  nscoord mMinWidth, mPrefWidth;
+
+  nsLineList mLines;
+
+  // List of all floats in this block
+  // XXXmats blocks rarely have floats, make it a frame property
+  nsFrameList mFloats;
+
+  friend class mozilla::BlockReflowInput;
+  friend class nsBlockInFlowLineIterator;
+
+#ifdef DEBUG
+public:
+  static bool gLamePaintMetrics;
+  static bool gLameReflowMetrics;
+  static bool gNoisy;
+  static bool gNoisyDamageRepair;
+  static bool gNoisyIntrinsic;
+  static bool gNoisyReflow;
+  static bool gReallyNoisyReflow;
+  static bool gNoisyFloatManager;
+  static bool gVerifyLines;
+  static bool gDisableResizeOpt;
+
+  static int32_t gNoiseIndent;
+
+  static const char* kReflowCommandType[];
+
+protected:
+  static void InitDebugFlags();
+#endif
+};
+
+#ifdef DEBUG
+class AutoNoisyIndenter {
+public:
+  explicit AutoNoisyIndenter(bool aDoIndent) : mIndented(aDoIndent) {
+    if (mIndented) {
+      nsBlockFrame::gNoiseIndent++;
+    }
+  }
+  ~AutoNoisyIndenter() {
+    if (mIndented) {
+      nsBlockFrame::gNoiseIndent--;
+    }
+  }
+private:
+  bool mIndented;
+};
+#endif
+
+/**
+ * Iterates over all lines in the prev-in-flows/next-in-flows of this block.
+ */
+class nsBlockInFlowLineIterator {
+public:
+  typedef nsBlockFrame::LineIterator LineIterator;
+  /**
+   * Set up the iterator to point to aLine which must be a normal line
+   * in aFrame (not an overflow line).
+   */
+  nsBlockInFlowLineIterator(nsBlockFrame* aFrame, LineIterator aLine);
+  /**
+   * Set up the iterator to point to the first line found starting from
+   * aFrame. Sets aFoundValidLine to false if there is no such line.
+   * After aFoundValidLine has returned false, don't call any methods on this
+   * object again.
+   */
+  nsBlockInFlowLineIterator(nsBlockFrame* aFrame, bool* aFoundValidLine);
+  /**
+   * Set up the iterator to point to the line that contains aFindFrame (either
+   * directly or indirectly).  If aFrame is out of flow, or contained in an
+   * out-of-flow, finds the line containing the out-of-flow's placeholder. If
+   * the frame is not found, sets aFoundValidLine to false. After
+   * aFoundValidLine has returned false, don't call any methods on this
+   * object again.
+   */
+  nsBlockInFlowLineIterator(nsBlockFrame* aFrame, nsIFrame* aFindFrame,
+                            bool* aFoundValidLine);
+
+  LineIterator GetLine() { return mLine; }
+  bool IsLastLineInList();
+  nsBlockFrame* GetContainer() { return mFrame; }
+  bool GetInOverflow() { return mLineList != &mFrame->mLines; }
+
+  /**
+   * Returns the current line list we're iterating, null means
+   * we're iterating |mLines| of the container.
+   */
+  nsLineList* GetLineList() { return mLineList; }
+
+  /**
+   * Returns the end-iterator of whatever line list we're in.
+   */
+  LineIterator End();
+
+  /**
+   * Returns false if there are no more lines. After this has returned false,
+   * don't call any methods on this object again.
+   */
+  bool Next();
+  /**
+   * Returns false if there are no more lines. After this has returned false,
+   * don't call any methods on this object again.
+   */
+  bool Prev();
+
+private:
+  friend class nsBlockFrame;
+  friend class nsBidiPresUtils;
+  // XXX nsBlockFrame uses this internally in one place.  Try to remove it.
+  // XXX uhm, and nsBidiPresUtils::Resolve too.
+  nsBlockInFlowLineIterator(nsBlockFrame* aFrame, LineIterator aLine, bool aInOverflow);
+
+  nsBlockFrame* mFrame;
+  LineIterator mLine;
+  nsLineList* mLineList;  // the line list mLine is in
+
+  /**
+   * Moves iterator to next valid line reachable from the current block.
+   * Returns false if there are no valid lines.
+   */
+  bool FindValidLine();
+};
+
+#endif /* nsBlockFrame_h___ */