Mozilla/mozilla/layout/mathml/base/src/nsMathMLForeignFrameWrapper.h

/* ***** BEGIN LICENSE BLOCK *****
 * Version: MPL 1.1/GPL 2.0/LGPL 2.1
 *
 * The contents of this file are subject to the Mozilla Public License Version
 * 1.1 (the "License"); you may not use this file except in compliance with
 * the License. You may obtain a copy of the License at
 * http://www.mozilla.org/MPL/
 *
 * Software distributed under the License is distributed on an "AS IS" basis,
 * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
 * for the specific language governing rights and limitations under the
 * License.
 *
 * The Original Code is Mozilla MathML Project.
 *
 * The Initial Developer of the Original Code is
 * The University Of Queensland.
 * Portions created by the Initial Developer are Copyright (C) 1999
 * the Initial Developer. All Rights Reserved.
 *
 * Contributor(s):
 *   Roger B. Sidje <rbs@maths.uq.edu.au>
 *
 * Alternatively, the contents of this file may be used under the terms of
 * either of the GNU General Public License Version 2 or later (the "GPL"),
 * or the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
 * in which case the provisions of the GPL or the LGPL are applicable instead
 * of those above. If you wish to allow use of your version of this file only
 * under the terms of either the GPL or the LGPL, and not to allow others to
 * use your version of this file under the terms of the MPL, indicate your
 * decision by deleting the provisions above and replace them with the notice
 * and other provisions required by the GPL or the LGPL. If you do not delete
 * the provisions above, a recipient may use your version of this file under
 * the terms of any one of the MPL, the GPL or the LGPL.
 *
 * ***** END LICENSE BLOCK ***** */

//
// a helper frame class to wrap non-MathML frames so that foreign elements 
// (e.g., html:img) can mix better with other surrounding MathML markups
//

#ifndef nsMathMLForeignFrameWrapper_h___
#define nsMathMLForeignFrameWrapper_h___

#include "nsCOMPtr.h"
#include "nsMathMLContainerFrame.h"

class nsMathMLForeignFrameWrapper : public nsBlockFrame,
                                    public nsMathMLFrame {
public:
  friend nsresult NS_NewMathMLForeignFrameWrapper(nsIPresShell* aPresShell, nsIFrame** aNewFrame);

  NS_DECL_ISUPPORTS_INHERITED

  // Overloaded nsIMathMLFrame methods

  NS_IMETHOD
  UpdatePresentationDataFromChildAt(PRInt32         aFirstIndex,
                                    PRInt32         aLastIndex,
                                    PRInt32         aScriptLevelIncrement,
                                    PRUint32        aFlagsValues,
                                    PRUint32        aFlagsToUpdate)
  {
    nsMathMLContainerFrame::PropagatePresentationDataFromChildAt(this,
      aFirstIndex, aLastIndex, aScriptLevelIncrement, aFlagsValues, aFlagsToUpdate);
    return NS_OK;
  }

  NS_IMETHOD
  ReResolveScriptStyle(PRInt32 aParentScriptLevel)
  {
    nsMathMLContainerFrame::PropagateScriptStyleFor(this, aParentScriptLevel);
    return NS_OK;
  }

  // overloaded nsBlockFrame methods

  NS_IMETHOD
  Init(nsPresContext*  aPresContext,
       nsIContent*      aContent,
       nsIFrame*        aParent,
       nsStyleContext*  aContext,
       nsIFrame*        aPrevInFlow);

#ifdef NS_DEBUG
  NS_IMETHOD
  SetInitialChildList(nsPresContext* aPresContext,
                      nsIAtom*        aListName,
                      nsIFrame*       aChildList)
  {
    nsresult rv = nsBlockFrame::SetInitialChildList(aPresContext, aListName, aChildList);
    // cannot use mFrames{.FirstChild()|.etc} since the block code doesn't set mFrames
    nsFrameList frameList(aChildList);
    NS_ASSERTION(frameList.FirstChild() && frameList.GetLength() == 1,
                 "there must be one and only one child frame");
    return rv;
  }
#endif

  NS_IMETHOD
  Reflow(nsPresContext*          aPresContext,
         nsHTMLReflowMetrics&     aDesiredSize,
         const nsHTMLReflowState& aReflowState,
         nsReflowStatus&          aStatus);

  // we are just a wrapper and these methods shouldn't be called
  NS_IMETHOD
  AppendFrames(nsIAtom*        aListName,
               nsIFrame*       aFrameList)
  {
    NS_NOTREACHED("unsupported operation");
    return NS_ERROR_NOT_IMPLEMENTED;
  }

  NS_IMETHOD
  InsertFrames(nsIAtom*        aListName,
               nsIFrame*       aPrevFrame,
               nsIFrame*       aFrameList)
  {
    NS_NOTREACHED("unsupported operation");
    return NS_ERROR_NOT_IMPLEMENTED;
  }

  // need special care here because the base class implementation treats this
  // as two operations: remove & insert; In our case, removing the child will
  // remove us too... so we have to operate from our parent's perspective
  NS_IMETHOD
  ReplaceFrame(nsIAtom*        aListName,
               nsIFrame*       aOldFrame,
               nsIFrame*       aNewFrame)
  {
    nsresult rv = mParent->ReplaceFrame(aListName, this, aNewFrame);
    // XXX the usage of ReplaceFrame() vs. ReplaceFrameAndDestroy() is
    // XXX ambiguous - see bug 122748. The style system doesn't call ReplaceFrame()
    // XXX and that's why nobody seems to have been biten by the ambiguity yet
    aOldFrame->Destroy(GetPresContext());
    return rv;
  }

  // Our life is bound to the life of our unique child.
  // When our child goes away, we ask our parent to delete us
  NS_IMETHOD
  RemoveFrame(nsIAtom*        aListName,
              nsIFrame*       aOldFrame)
  {
    return mParent->RemoveFrame(aListName, this);
  }

protected:
  nsMathMLForeignFrameWrapper() {}
  virtual ~nsMathMLForeignFrameWrapper() {}
};

#endif /* nsMathMLForeignFrameWrapper_h___ */