[MathML only - candidate version for 0.9x] * Hooked robust support for advanced dynamic updates via JavaScript and the DOM across the entire MathML module (with particular attention to the numerous presentational attributes that MathML has). * Eliminated some functions (or folded their functionality into recently added APIs). * Reviewed the module as a whole and simplified several chunks of code owing to the benefit of hindsight now. * Added/reviewed the documentation in anticipation of the freezing of Mozilla 1.0, to improve the understanding of people that may read the archived code and learn from it under the appropriate context of this time. * Reviewed the XXX comments and addressed those that could be addressable in this timeframe. * Some renamings (e.g., ReLayout -> ReLayoutChildren to avoid ambiguities as to who does what in terms of the terminology used when referring to the frame hierarchy).

git-svn-id: svn://10.0.0.236/trunk@113879 18797224-902f-48f8-a5cc-f745e15eee43

mozilla/layout/mathml/base/src/nsMathMLmmultiscriptsFrame.cpp

@@ -68,15 +68,63 @@ nsMathMLmmultiscriptsFrame::~nsMathMLmmultiscriptsFrame()
 }
 
 NS_IMETHODIMP
-nsMathMLmmultiscriptsFrame::Init(nsIPresContext*  aPresContext,
-                                 nsIContent*      aContent,
-                                 nsIFrame*        aParent,
-                                 nsIStyleContext* aContext,
-                                 nsIFrame*        aPrevInFlow)
+nsMathMLmmultiscriptsFrame::TransmitAutomaticData(nsIPresContext* aPresContext)
 {
-  nsresult rv = nsMathMLContainerFrame::Init
-    (aPresContext, aContent, aParent, aContext, aPrevInFlow);
+  // if our base is an embellished operator, let its state bubble to us
+  GetEmbellishDataFrom(mFrames.FirstChild(), mEmbellishData);
+  if (NS_MATHML_IS_EMBELLISH_OPERATOR(mEmbellishData.flags))
+    mEmbellishData.nextFrame = mFrames.FirstChild();
 
+  // The REC says:
+  // The <mmultiscripts> element increments scriptlevel by 1, and sets
+  // displaystyle to "false", within each of its arguments except base
+  UpdatePresentationDataFromChildAt(aPresContext, 1, -1, 1,
+    ~NS_MATHML_DISPLAYSTYLE, NS_MATHML_DISPLAYSTYLE);
+
+  // The TeXbook (Ch 17. p.141) says the superscript inherits the compression
+  // while the subscript is compressed. So here we collect subscripts and set
+  // the compression flag in them.
+  PRInt32 count = 0;
+  PRBool isSubScript = PR_FALSE;
+  nsAutoVoidArray subScriptFrames;
+  nsIFrame* childFrame = mFrames.FirstChild();
+  while (childFrame) {
+    nsCOMPtr<nsIContent> childContent;
+    nsCOMPtr<nsIAtom> childTag;
+    childFrame->GetContent(getter_AddRefs(childContent));
+    childContent->GetTag(*getter_AddRefs(childTag));
+    if (childTag.get() == nsMathMLAtoms::mprescripts_) {
+      // mprescripts frame
+    }
+    else if (0 == count) {
+      // base frame
+    }
+    else {
+      // super/subscript block
+      if (isSubScript) {
+        // subscript
+        subScriptFrames.AppendElement(childFrame);
+      }
+      else {
+        // superscript
+      }
+      isSubScript = !isSubScript;
+    }
+    count++;
+    childFrame->GetNextSibling(&childFrame);
+  }
+  for (PRInt32 i = subScriptFrames.Count() - 1; i >= 0; i--) {
+    childFrame = (nsIFrame*)subScriptFrames[i];
+    PropagatePresentationDataFor(aPresContext, childFrame, 0,
+      NS_MATHML_COMPRESSED, NS_MATHML_COMPRESSED);
+  }
+
+  return NS_OK;
+}
+
+void
+nsMathMLmmultiscriptsFrame::ProcessAttributes(nsIPresContext* aPresContext)
+{
   mSubScriptShift = 0;
   mSupScriptShift = 0;
   mScriptSpace = NSFloatPointsToTwips(0.5f); // 0.5pt as in plain TeX
@@ -98,27 +146,6 @@ nsMathMLmmultiscriptsFrame::Init(nsIPresContext*  aPresContext,
       mSupScriptShift = CalcLength(aPresContext, mStyleContext, cssValue);
     }
   }
-
-  return rv;
-}
-
-NS_IMETHODIMP
-nsMathMLmmultiscriptsFrame::TransmitAutomaticData(nsIPresContext* aPresContext)
-{
-#if defined(NS_DEBUG) && defined(SHOW_BOUNDING_BOX)
-  mPresentationData.flags |= NS_MATHML_SHOW_BOUNDING_METRICS;
-#endif
-
-  // check whether or not this is an embellished operator
-  EmbellishOperator();
-  // The REC says:
-  // The <mmultiscripts> element increments scriptlevel by 1, and sets
-  // displaystyle to "false", within each of its arguments except base, but
-  // leaves both attributes unchanged within base. 
-  // XXX Need to update the compression flags in the sub/sup pairs as per TeX
-  UpdatePresentationDataFromChildAt(aPresContext, 1, -1, 1,
-    ~NS_MATHML_DISPLAYSTYLE, NS_MATHML_DISPLAYSTYLE);
-  return NS_OK;
 }
 
 NS_IMETHODIMP
@@ -127,8 +154,6 @@ nsMathMLmmultiscriptsFrame::Place(nsIPresContext*      aPresContext,
                                   PRBool               aPlaceOrigin,
                                   nsHTMLReflowMetrics& aDesiredSize)
 {
-  nsresult rv = NS_OK;
-
   ////////////////////////////////////
   // Get the children's desired sizes
 
@@ -139,16 +164,9 @@ nsMathMLmmultiscriptsFrame::Place(nsIPresContext*      aPresContext,
   // depend only on the current font
   ////////////////////////////////////////
 
-  // get x-height (an ex)
-#if 0
-  nscoord xHeight = 0;
-  nsCOMPtr<nsIFontMetrics> fm;
-  const nsStyleFont* aFont =
-    (const nsStyleFont*) mStyleContext->GetStyleData (eStyleStruct_Font);
-  aPresContext->GetMetricsFor (aFont->mFont, getter_AddRefs(fm));
-  fm->GetXHeight (xHeight);
-#endif
+  ProcessAttributes(aPresContext);
 
+  // get x-height (an ex)
   const nsStyleFont *font = NS_STATIC_CAST(const nsStyleFont*,
     mStyleContext->GetStyleData(eStyleStruct_Font));
   aRenderingContext.SetFont(font->mFont);
@@ -244,11 +262,9 @@ nsMathMLmmultiscriptsFrame::Place(nsIPresContext*      aPresContext,
   nsBoundingMetrics bmBase, bmSubScript, bmSupScript;
   nscoord italicCorrection = 0;
 
-  // XXX is there an NSPR macro for int_max ???
-  mBoundingMetrics.ascent = mBoundingMetrics.descent = -10000000;
   mBoundingMetrics.width = 0;
-
-  aDesiredSize.ascent = aDesiredSize.descent = -10000000;
+  mBoundingMetrics.ascent = mBoundingMetrics.descent = -0x7FFFFFFF;
+  aDesiredSize.ascent = aDesiredSize.descent = -0x7FFFFFFF;
   aDesiredSize.width = aDesiredSize.height = 0;
 
   nsIFrame* childFrame = mFrames.FirstChild();
@@ -259,6 +275,12 @@ nsMathMLmmultiscriptsFrame::Place(nsIPresContext*      aPresContext,
     childContent->GetTag(*getter_AddRefs(childTag));
 
     if (childTag.get() == nsMathMLAtoms::mprescripts_) {
+      if (mprescriptsFrame) {
+        // duplicate <mprescripts/> found
+        // report an error, encourage people to get their markups in order
+        NS_WARNING("invalid markup");
+        return ReflowError(aPresContext, aRenderingContext, aDesiredSize);
+      }
       mprescriptsFrame = childFrame;
       firstPrescriptsPair = PR_TRUE;
     }
@@ -446,5 +468,5 @@ nsMathMLmmultiscriptsFrame::Place(nsIPresContext*      aPresContext,
     } while (mprescriptsFrame != childFrame);
   }
 
-  return rv;
+  return NS_OK;
 }