The Tor Browser: layout/mathml/nsMathMLContainerFrame.h@925c144e1f1f (annotated)

layout/mathml/nsMathMLContainerFrame.h@925c144e1f1f (annotated)

layout/mathml/nsMathMLContainerFrame.h

Fri, 16 Jan 2015 18:13:44 +0100

author: Michael Schloh von Bennewitz <michael@schloh.com>
date: Fri, 16 Jan 2015 18:13:44 +0100
branch: TOR_BUG_9701
changeset 14: 925c144e1f1f
permissions: -rw-r--r--

Integrate suggestion from review to improve consistency with existing code.

 /* -*- 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/. */
 #ifndef nsMathMLContainerFrame_h___
 #define nsMathMLContainerFrame_h___
 #include "mozilla/Attributes.h"
 #include "nsContainerFrame.h"
 #include "nsBlockFrame.h"
 #include "nsInlineFrame.h"
 #include "nsMathMLOperators.h"
 #include "nsMathMLFrame.h"
 #include "mozilla/Likely.h"
 /*
  * Base class for MathML container frames. It acts like an inferred
  * mrow. By default, this frame uses its Reflow() method to lay its
  * children horizontally and ensure that their baselines are aligned.
  * The Reflow() method relies upon Place() to position children.
  * By overloading Place() in derived classes, it is therefore possible
  * to position children in various customized ways.
  */
 // Options for the preferred size at which to stretch our stretchy children
 #define STRETCH_CONSIDER_ACTUAL_SIZE    0x00000001 // just use our current size
 #define STRETCH_CONSIDER_EMBELLISHMENTS 0x00000002 // size calculations include embellishments
 class nsMathMLContainerFrame : public nsContainerFrame,
                                public nsMathMLFrame {
   friend class nsMathMLmfencedFrame;
 public:
   nsMathMLContainerFrame(nsStyleContext* aContext) : nsContainerFrame(aContext) {}
   NS_DECL_QUERYFRAME_TARGET(nsMathMLContainerFrame)
   NS_DECL_QUERYFRAME
   NS_DECL_FRAMEARENA_HELPERS
   // --------------------------------------------------------------------------
   // Overloaded nsMathMLFrame methods -- see documentation in nsIMathMLFrame.h
   NS_IMETHOD
   Stretch(nsRenderingContext& aRenderingContext,
           nsStretchDirection   aStretchDirection,
           nsBoundingMetrics&   aContainerSize,
           nsHTMLReflowMetrics& aDesiredStretchSize) MOZ_OVERRIDE;
   NS_IMETHOD
   UpdatePresentationDataFromChildAt(int32_t         aFirstIndex,
                                     int32_t         aLastIndex,
                                     uint32_t        aFlagsValues,
                                     uint32_t        aFlagsToUpdate) MOZ_OVERRIDE
   {
     PropagatePresentationDataFromChildAt(this, aFirstIndex, aLastIndex,
       aFlagsValues, aFlagsToUpdate);
     return NS_OK;
   }
   // helper to set the "increment script level" flag on the element belonging
   // to a child frame given by aChildIndex.
   // When this flag is set, the style system will increment the scriptlevel
   // for the child element. This is needed for situations where the style system
   // cannot itself determine the scriptlevel (mfrac, munder, mover, munderover).
   // This should be called during reflow. We set the flag and if it changed,
   // we request appropriate restyling and also queue a post-reflow callback
   // to ensure that restyle and reflow happens immediately after the current
   // reflow.
   void
   SetIncrementScriptLevel(int32_t aChildIndex, bool aIncrement);
   // --------------------------------------------------------------------------
   // Overloaded nsContainerFrame methods -- see documentation in nsIFrame.h
   virtual bool IsFrameOfType(uint32_t aFlags) const MOZ_OVERRIDE
   {
     return !(aFlags & nsIFrame::eLineParticipant) &&
       nsContainerFrame::IsFrameOfType(aFlags &
               ~(nsIFrame::eMathML | nsIFrame::eExcludesIgnorableWhitespace));
   }
   virtual nsresult
   AppendFrames(ChildListID     aListID,
                nsFrameList&    aFrameList) MOZ_OVERRIDE;
   virtual nsresult
   InsertFrames(ChildListID     aListID,
                nsIFrame*       aPrevFrame,
                nsFrameList&    aFrameList) MOZ_OVERRIDE;
   virtual nsresult
   RemoveFrame(ChildListID     aListID,
               nsIFrame*       aOldFrame) MOZ_OVERRIDE;
   /**
    * Both GetMinWidth and GetPrefWidth use the intrinsic width metrics
    * returned by GetIntrinsicMetrics, including ink overflow.
    */
   virtual nscoord GetMinWidth(nsRenderingContext *aRenderingContext) MOZ_OVERRIDE;
   virtual nscoord GetPrefWidth(nsRenderingContext *aRenderingContext) MOZ_OVERRIDE;
   /**
    * Return the intrinsic horizontal metrics of the frame's content area.
    */
   virtual void
   GetIntrinsicWidthMetrics(nsRenderingContext* aRenderingContext,
                            nsHTMLReflowMetrics& aDesiredSize);
   virtual nsresult
   Reflow(nsPresContext*          aPresContext,
          nsHTMLReflowMetrics&     aDesiredSize,
          const nsHTMLReflowState& aReflowState,
          nsReflowStatus&          aStatus) MOZ_OVERRIDE;
   virtual nsresult
   WillReflow(nsPresContext* aPresContext) MOZ_OVERRIDE
   {
     mPresentationData.flags &= ~NS_MATHML_ERROR;
     return nsContainerFrame::WillReflow(aPresContext);
   }
   virtual nsresult
   DidReflow(nsPresContext*           aPresContext,
             const nsHTMLReflowState*  aReflowState,
             nsDidReflowStatus         aStatus) MOZ_OVERRIDE
   {
     mPresentationData.flags &= ~NS_MATHML_STRETCH_DONE;
     return nsContainerFrame::DidReflow(aPresContext, aReflowState, aStatus);
   }
   virtual void BuildDisplayList(nsDisplayListBuilder*   aBuilder,
                                 const nsRect&           aDirtyRect,
                                 const nsDisplayListSet& aLists) MOZ_OVERRIDE;
   virtual bool UpdateOverflow() MOZ_OVERRIDE;
   // Notification when an attribute is changed. The MathML module uses the
   // following paradigm:
   //
   // 1. If the MathML frame class doesn't have any cached automatic data that
   //    depends on the attribute: we just reflow (e.g., this happens with <msub>,
   //    <msup>, <mmultiscripts>, etc). This is the default behavior implemented
   //    by this base class.
   //
   // 2. If the MathML frame class has cached automatic data that depends on
   //    the attribute:
   //    2a. If the automatic data to update resides only within the descendants,
   //        we just re-layout them using ReLayoutChildren(this);
   //        (e.g., this happens with <ms>).
   //    2b. If the automatic data to update affects us in some way, we ask our parent
   //        to re-layout its children using ReLayoutChildren(mParent);
   //        Therefore, there is an overhead here in that our siblings are re-laid
   //        too (e.g., this happens with <munder>, <mover>, <munderover>).
   virtual nsresult
   AttributeChanged(int32_t         aNameSpaceID,
                    nsIAtom*        aAttribute,
                    int32_t         aModType) MOZ_OVERRIDE;
   // helper function to apply mirroring to a horizontal coordinate, if needed.
   nscoord
   MirrorIfRTL(nscoord aParentWidth, nscoord aChildWidth, nscoord aChildLeading)
   {
     return (StyleVisibility()->mDirection ?
             aParentWidth - aChildWidth - aChildLeading : aChildLeading);
   }
   // --------------------------------------------------------------------------
   // Additional methods
 protected:
   /* Place :
    * This method is used to measure or position child frames and other
    * elements.  It may be called any number of times with aPlaceOrigin
    * false to measure, and the final call of the Reflow process before
    * returning from Reflow() or Stretch() will have aPlaceOrigin true
    * to position the elements.
    *
    * IMPORTANT: This method uses GetReflowAndBoundingMetricsFor() which must
    * have been set up with SaveReflowAndBoundingMetricsFor().
    *
    * The Place() method will use this information to compute the desired size
    * of the frame.
    *
    * @param aPlaceOrigin [in]
    *        If aPlaceOrigin is false, compute your desired size using the
    *        information from GetReflowAndBoundingMetricsFor.  However, child
    *        frames or other elements should not be repositioned.
    *
    *        If aPlaceOrigin is true, reflow is finished. You should position
    *        all your children, and return your desired size. You should now
    *        use FinishReflowChild() on your children to complete post-reflow
    *        operations.
    *
    * @param aDesiredSize [out] parameter where you should return your desired
    *        size and your ascent/descent info. Compute your desired size using
    *        the information from GetReflowAndBoundingMetricsFor, and include
    *        any space you want for border/padding in the desired size you
    *        return.
    */
   virtual nsresult
   Place(nsRenderingContext& aRenderingContext,
         bool                 aPlaceOrigin,
         nsHTMLReflowMetrics& aDesiredSize);
   // MeasureForWidth:
   //
   // A method used by nsMathMLContainerFrame::GetIntrinsicWidth to get the
   // width that a particular Place method desires.  For most frames, this will
   // just call the object's Place method.  However <msqrt> and <menclose> use
   // nsMathMLContainerFrame::GetIntrinsicWidth to measure the child frames as
   // if in an <mrow>, and so their frames implement MeasureForWidth to use
   // nsMathMLContainerFrame::Place.
   virtual nsresult
   MeasureForWidth(nsRenderingContext& aRenderingContext,
                   nsHTMLReflowMetrics& aDesiredSize);
   // helper to re-sync the automatic data in our children and notify our parent to
   // reflow us when changes (e.g., append/insert/remove) happen in our child list
   virtual nsresult
   ChildListChanged(int32_t aModType);
   // helper to get the preferred size that a container frame should use to fire
   // the stretch on its stretchy child frames.
   void
   GetPreferredStretchSize(nsRenderingContext& aRenderingContext,
                           uint32_t             aOptions,
                           nsStretchDirection   aStretchDirection,
                           nsBoundingMetrics&   aPreferredStretchSize);
   // helper used by mstyle, mphantom, mpadded and mrow in their implementation
   // of TransmitAutomaticData() to determine whether they are space-like.
   nsresult
   TransmitAutomaticDataForMrowLikeElement();
 public:
   // error handlers to provide a visual feedback to the user when an error
   // (typically invalid markup) was encountered during reflow.
   nsresult
   ReflowError(nsRenderingContext& aRenderingContext,
               nsHTMLReflowMetrics& aDesiredSize);
   /*
    * Helper to call ReportErrorToConsole for parse errors involving
    * attribute/value pairs.
    * @param aAttribute The attribute for which the parse error occured.
    * @param aValue The value for which the parse error occured.
    */
   nsresult
   ReportParseError(const char16_t*           aAttribute,
                    const char16_t*           aValue);
   /*
    * Helper to call ReportErrorToConsole when certain tags
    * have more than the expected amount of children.
    */
   nsresult
   ReportChildCountError();
   /*
    * Helper to call ReportErrorToConsole when certain tags have
    * invalid child tags
    * @param aChildTag The tag which is forbidden in this context
    */
   nsresult
   ReportInvalidChildError(nsIAtom* aChildTag);
   /*
    * Helper to call ReportToConsole when an error occurs.
    * @param aParams see nsContentUtils::ReportToConsole
    */
   nsresult
   ReportErrorToConsole(const char*       aErrorMsgId,
                        const char16_t** aParams = nullptr,
                        uint32_t          aParamCount = 0);
   // helper method to reflow a child frame. We are inline frames, and we don't
   // know our positions until reflow is finished. That's why we ask the
   // base method not to worry about our position.
   nsresult
   ReflowChild(nsIFrame*                aKidFrame,
               nsPresContext*          aPresContext,
               nsHTMLReflowMetrics&     aDesiredSize,
               const nsHTMLReflowState& aReflowState,
               nsReflowStatus&          aStatus);
 protected:
   // helper to add the inter-spacing when <math> is the immediate parent.
   // Since we don't (yet) handle the root <math> element ourselves, we need to
   // take special care of the inter-frame spacing on elements for which <math>
   // is the direct xml parent. This function will be repeatedly called from
   // left to right on the childframes of <math>, and by so doing it will
   // emulate the spacing that would have been done by a <mrow> container.
   // e.g., it fixes <math> <mi>f</mi> <mo>q</mo> <mi>f</mi> <mo>I</mo> </math>
   virtual nscoord
   FixInterFrameSpacing(nsHTMLReflowMetrics& aDesiredSize);
   // helper method to complete the post-reflow hook and ensure that embellished
   // operators don't terminate their Reflow without receiving a Stretch command.
   virtual nsresult
   FinalizeReflow(nsRenderingContext& aRenderingContext,
                  nsHTMLReflowMetrics& aDesiredSize);
   // Record metrics of a child frame for recovery through the following method
   static void
   SaveReflowAndBoundingMetricsFor(nsIFrame*                  aFrame,
                                   const nsHTMLReflowMetrics& aReflowMetrics,
                                   const nsBoundingMetrics&   aBoundingMetrics);
   // helper method to facilitate getting the reflow and bounding metrics of a
   // child frame.  The argument aMathMLFrameType, when non null, will return
   // the 'type' of the frame, which is used to determine the inter-frame
   // spacing.
   // IMPORTANT: This function is only meant to be called in Place() methods as
   // the information is available only when set up with the above method
   // during Reflow/Stretch() and GetPrefWidth().
   static void
   GetReflowAndBoundingMetricsFor(nsIFrame*            aFrame,
                                  nsHTMLReflowMetrics& aReflowMetrics,
                                  nsBoundingMetrics&   aBoundingMetrics,
                                  eMathMLFrameType*    aMathMLFrameType = nullptr);
   // helper method to clear metrics saved with
   // SaveReflowAndBoundingMetricsFor() from all child frames.
   void ClearSavedChildMetrics();
   // helper to let the update of presentation data pass through
   // a subtree that may contain non-MathML container frames
   static void
   PropagatePresentationDataFor(nsIFrame*       aFrame,
                                uint32_t        aFlagsValues,
                                uint32_t        aFlagsToUpdate);
 public:
   static void
   PropagatePresentationDataFromChildAt(nsIFrame*       aParentFrame,
                                        int32_t         aFirstChildIndex,
                                        int32_t         aLastChildIndex,
                                        uint32_t        aFlagsValues,
                                        uint32_t        aFlagsToUpdate);
   // Sets flags on aFrame and all descendant frames
   static void
   PropagateFrameFlagFor(nsIFrame* aFrame,
                         nsFrameState aFlags);
   // helper to let the rebuild of automatic data (presentation data
   // and embellishement data) walk through a subtree that may contain
   // non-MathML container frames. Note that this method re-builds the
   // automatic data in the children -- not in aParentFrame itself (except
   // for those particular operations that the parent frame may do in its
   // TransmitAutomaticData()). The reason it works this way is because
   // a container frame knows what it wants for its children, whereas children
   // have no clue who their parent is. For example, it is <mfrac> who knows
   // that its children have to be in scriptsizes, and has to transmit this
   // information to them. Hence, when changes occur in a child frame, the child
   // has to request the re-build from its parent. Unfortunately, the extra cost
   // for this is that it will re-sync in the siblings of the child as well.
   static void
   RebuildAutomaticDataForChildren(nsIFrame* aParentFrame);
   // helper to blow away the automatic data cached in a frame's subtree and
   // re-layout its subtree to reflect changes that may have happen. In the
   // event where aParentFrame isn't a MathML frame, it will first walk up to
   // the ancestor that is a MathML frame, and re-layout from there -- this is
   // to guarantee that automatic data will be rebuilt properly. Note that this
   // method re-builds the automatic data in the children -- not in the parent
   // frame itself (except for those particular operations that the parent frame
   // may do do its TransmitAutomaticData()). @see RebuildAutomaticDataForChildren
   //
   // aBits are the bits to pass to FrameNeedsReflow() when we call it.
   static nsresult
   ReLayoutChildren(nsIFrame* aParentFrame);
 protected:
   // Helper method which positions child frames as an <mrow> on given baseline
   // y = aBaseline starting from x = aOffsetX, calling FinishReflowChild()
   // on the frames.
   void
   PositionRowChildFrames(nscoord aOffsetX, nscoord aBaseline);
   // A variant on FinishAndStoreOverflow() that uses the union of child
   // overflows, the frame bounds, and mBoundingMetrics to set and store the
   // overflow.
   void GatherAndStoreOverflow(nsHTMLReflowMetrics* aMetrics);
   /**
    * Call DidReflow() if the NS_FRAME_IN_REFLOW frame bit is set on aFirst and
    * all its next siblings up to, but not including, aStop.
    * aStop == nullptr meaning all next siblings with the bit set.
    * The method does nothing if aFirst == nullptr.
    */
   static void DidReflowChildren(nsIFrame* aFirst, nsIFrame* aStop = nullptr);
 private:
   class RowChildFrameIterator;
   friend class RowChildFrameIterator;
 };
 // --------------------------------------------------------------------------
 // Currently, to benefit from line-breaking inside the <math> element, <math> is
 // simply mapping to nsBlockFrame or nsInlineFrame.
 // A separate implemention needs to provide:
 // 1) line-breaking
 // 2) proper inter-frame spacing
 // 3) firing of Stretch() (in which case FinalizeReflow() would have to be cleaned)
 // Issues: If/when mathml becomes a pluggable component, the separation will be needed.
 class nsMathMLmathBlockFrame : public nsBlockFrame {
 public:
   NS_DECL_QUERYFRAME_TARGET(nsMathMLmathBlockFrame)
   NS_DECL_QUERYFRAME
   NS_DECL_FRAMEARENA_HELPERS
   friend nsIFrame* NS_NewMathMLmathBlockFrame(nsIPresShell* aPresShell,
           nsStyleContext* aContext, nsFrameState aFlags);
   // beware, mFrames is not set by nsBlockFrame
   // cannot use mFrames{.FirstChild()|.etc} since the block code doesn't set mFrames
   virtual nsresult
   SetInitialChildList(ChildListID     aListID,
                       nsFrameList&    aChildList) MOZ_OVERRIDE
   {
     NS_ASSERTION(aListID == kPrincipalList, "unexpected frame list");
     nsresult rv = nsBlockFrame::SetInitialChildList(aListID, aChildList);
     // re-resolve our subtree to set any mathml-expected data
     nsMathMLContainerFrame::RebuildAutomaticDataForChildren(this);
     return rv;
   }
   virtual nsresult
   AppendFrames(ChildListID     aListID,
                nsFrameList&    aFrameList) MOZ_OVERRIDE
   {
     NS_ASSERTION(aListID == kPrincipalList || aListID == kNoReflowPrincipalList,
                  "unexpected frame list");
     nsresult rv = nsBlockFrame::AppendFrames(aListID, aFrameList);
     if (MOZ_LIKELY(aListID == kPrincipalList))
       nsMathMLContainerFrame::ReLayoutChildren(this);
     return rv;
   }
   virtual nsresult
   InsertFrames(ChildListID     aListID,
                nsIFrame*       aPrevFrame,
                nsFrameList&    aFrameList) MOZ_OVERRIDE
   {
     NS_ASSERTION(aListID == kPrincipalList || aListID == kNoReflowPrincipalList,
                  "unexpected frame list");
     nsresult rv = nsBlockFrame::InsertFrames(aListID, aPrevFrame, aFrameList);
     if (MOZ_LIKELY(aListID == kPrincipalList))
       nsMathMLContainerFrame::ReLayoutChildren(this);
     return rv;
   }
   virtual nsresult
   RemoveFrame(ChildListID     aListID,
               nsIFrame*       aOldFrame) MOZ_OVERRIDE
   {
     NS_ASSERTION(aListID == kPrincipalList || aListID == kNoReflowPrincipalList,
                  "unexpected frame list");
     nsresult rv = nsBlockFrame::RemoveFrame(aListID, aOldFrame);
     if (MOZ_LIKELY(aListID == kPrincipalList))
       nsMathMLContainerFrame::ReLayoutChildren(this);
     return rv;
   }
   virtual bool IsFrameOfType(uint32_t aFlags) const MOZ_OVERRIDE {
     return nsBlockFrame::IsFrameOfType(aFlags &
               ~(nsIFrame::eMathML | nsIFrame::eExcludesIgnorableWhitespace));
   }
   // See nsIMathMLFrame.h
   bool IsMrowLike() {
     return mFrames.FirstChild() != mFrames.LastChild() ||
            !mFrames.FirstChild();
   }
 protected:
   nsMathMLmathBlockFrame(nsStyleContext* aContext) : nsBlockFrame(aContext) {
     // We should always have a float manager.  Not that things can really try
     // to float out of us anyway, but we need one for line layout.
     AddStateBits(NS_BLOCK_FLOAT_MGR);
   }
   virtual ~nsMathMLmathBlockFrame() {}
 };
 // --------------
 class nsMathMLmathInlineFrame : public nsInlineFrame,
                                 public nsMathMLFrame {
 public:
   NS_DECL_QUERYFRAME_TARGET(nsMathMLmathInlineFrame)
   NS_DECL_QUERYFRAME
   NS_DECL_FRAMEARENA_HELPERS
   friend nsIFrame* NS_NewMathMLmathInlineFrame(nsIPresShell* aPresShell, nsStyleContext* aContext);
   virtual nsresult
   SetInitialChildList(ChildListID     aListID,
                       nsFrameList&    aChildList) MOZ_OVERRIDE
   {
     NS_ASSERTION(aListID == kPrincipalList, "unexpected frame list");
     nsresult rv = nsInlineFrame::SetInitialChildList(aListID, aChildList);
     // re-resolve our subtree to set any mathml-expected data
     nsMathMLContainerFrame::RebuildAutomaticDataForChildren(this);
     return rv;
   }
   virtual nsresult
   AppendFrames(ChildListID     aListID,
                nsFrameList&    aFrameList) MOZ_OVERRIDE
   {
     NS_ASSERTION(aListID == kPrincipalList || aListID == kNoReflowPrincipalList,
                  "unexpected frame list");
     nsresult rv = nsInlineFrame::AppendFrames(aListID, aFrameList);
     if (MOZ_LIKELY(aListID == kPrincipalList))
       nsMathMLContainerFrame::ReLayoutChildren(this);
     return rv;
   }
   virtual nsresult
   InsertFrames(ChildListID     aListID,
                nsIFrame*       aPrevFrame,
                nsFrameList&    aFrameList) MOZ_OVERRIDE
   {
     NS_ASSERTION(aListID == kPrincipalList || aListID == kNoReflowPrincipalList,
                  "unexpected frame list");
     nsresult rv = nsInlineFrame::InsertFrames(aListID, aPrevFrame, aFrameList);
     if (MOZ_LIKELY(aListID == kPrincipalList))
       nsMathMLContainerFrame::ReLayoutChildren(this);
     return rv;
   }
   virtual nsresult
   RemoveFrame(ChildListID     aListID,
               nsIFrame*       aOldFrame) MOZ_OVERRIDE
   {
     NS_ASSERTION(aListID == kPrincipalList || aListID == kNoReflowPrincipalList,
                  "unexpected frame list");
     nsresult rv = nsInlineFrame::RemoveFrame(aListID, aOldFrame);
     if (MOZ_LIKELY(aListID == kPrincipalList))
       nsMathMLContainerFrame::ReLayoutChildren(this);
     return rv;
   }
   virtual bool IsFrameOfType(uint32_t aFlags) const MOZ_OVERRIDE {
       return nsInlineFrame::IsFrameOfType(aFlags &
                 ~(nsIFrame::eMathML | nsIFrame::eExcludesIgnorableWhitespace));
   }
   bool
   IsMrowLike() MOZ_OVERRIDE {
     return mFrames.FirstChild() != mFrames.LastChild() ||
            !mFrames.FirstChild();
   }
 protected:
   nsMathMLmathInlineFrame(nsStyleContext* aContext) : nsInlineFrame(aContext) {}
   virtual ~nsMathMLmathInlineFrame() {}
 };
 #endif /* nsMathMLContainerFrame_h___ */

The Tor Browser / annotate

layout/mathml/nsMathMLContainerFrame.h@925c144e1f1f (annotated)

layout/mathml/nsMathMLContainerFrame.h