/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* ----- 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 the Mozilla SVG project.
 *
 * The Initial Developer of the Original Code is 
 * Crocodile Clips Ltd..
 * Portions created by the Initial Developer are Copyright (C) 2002
 * the Initial Developer. All Rights Reserved.
 *
 * Contributor(s):
 *    Alex Fritze <alex.fritze@crocodile-clips.com> (original author)
 *
 * Alternatively, the contents of this file may be used under the terms of
 * either 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 NPL, 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 ----- */

#include "nsContainerFrame.h"
#include "nsIDOMSVGTSpanElement.h"
#include "nsIPresContext.h"
#include "nsISVGTextContainerFrame.h"
#include "nsISVGRendererCanvas.h"
#include "nsWeakReference.h"
#include "nsISVGValue.h"
#include "nsISVGValueObserver.h"
#include "nsIDOMSVGSVGElement.h"
#include "nsIDOMSVGMatrix.h"
#include "nsIDOMSVGLengthList.h"
#include "nsIDOMSVGLength.h"
#include "nsISVGValueUtils.h"
#include "nsIDOMSVGAnimatedLengthList.h"
#include "nsISVGContainerFrame.h"
#include "nsISVGChildFrame.h"
#include "nsISVGTextFrame.h"
#include "nsISVGGlyphFragmentNode.h"
#include "nsIDOMSVGRect.h"
#include "nsISVGOuterSVGFrame.h"

typedef nsContainerFrame nsSVGTSpanFrameBase;

class nsSVGTSpanFrame : public nsSVGTSpanFrameBase,
                        public nsISVGTextContainerFrame,
                        public nsISVGGlyphFragmentNode,
                        public nsISVGChildFrame,
                        public nsISVGContainerFrame,
                        public nsISVGValueObserver,
                        public nsSupportsWeakReference
{
  friend nsresult
  NS_NewSVGTSpanFrame(nsIPresShell* aPresShell, nsIContent* aContent,
                      nsIFrame* parentFrame, nsIFrame** aNewFrame);
protected:
  nsSVGTSpanFrame();
  virtual ~nsSVGTSpanFrame();
  nsresult Init();
  
   // nsISupports interface:
  NS_IMETHOD QueryInterface(const nsIID& aIID, void** aInstancePtr);
private:
  NS_IMETHOD_(nsrefcnt) AddRef() { return NS_OK; }
  NS_IMETHOD_(nsrefcnt) Release() { return NS_OK; }  
public:
  // nsIFrame:

  NS_IMETHOD  AppendFrames(nsIPresContext* aPresContext,
                           nsIPresShell&   aPresShell,
                           nsIAtom*        aListName,
                           nsIFrame*       aFrameList);
  NS_IMETHOD  InsertFrames(nsIPresContext* aPresContext,
                           nsIPresShell&   aPresShell,
                           nsIAtom*        aListName,
                           nsIFrame*       aPrevFrame,
                           nsIFrame*       aFrameList);
  NS_IMETHOD  RemoveFrame(nsIPresContext* aPresContext,
                          nsIPresShell&   aPresShell,
                          nsIAtom*        aListName,
                          nsIFrame*       aOldFrame);
  NS_IMETHOD  ReplaceFrame(nsIPresContext* aPresContext,
                           nsIPresShell&   aPresShell,
                           nsIAtom*        aListName,
                           nsIFrame*       aOldFrame,
                           nsIFrame*       aNewFrame);
  NS_IMETHOD Init(nsIPresContext*  aPresContext,
                  nsIContent*      aContent,
                  nsIFrame*        aParent,
                  nsStyleContext*  aContext,
                  nsIFrame*        aPrevInFlow);


  // nsISVGValueObserver
  NS_IMETHOD WillModifySVGObservable(nsISVGValue* observable);
  NS_IMETHOD DidModifySVGObservable (nsISVGValue* observable);

  // nsISupportsWeakReference
  // implementation inherited from nsSupportsWeakReference
  
  // nsISVGChildFrame interface:
  NS_IMETHOD Paint(nsISVGRendererCanvas* canvas, const nsRect& dirtyRectTwips);
  NS_IMETHOD GetFrameForPoint(float x, float y, nsIFrame** hit);
  NS_IMETHOD_(already_AddRefed<nsISVGRendererRegion>) GetCoveredRegion();
  NS_IMETHOD InitialUpdate();
  NS_IMETHOD NotifyCTMChanged();
  NS_IMETHOD NotifyRedrawSuspended();
  NS_IMETHOD NotifyRedrawUnsuspended();
  NS_IMETHOD GetBBox(nsIDOMSVGRect **_retval);
  
  // nsISVGContainerFrame interface:
  NS_IMETHOD_(nsISVGOuterSVGFrame *) GetOuterSVGFrame();
  
  // nsISVGTextContainerFrame interface:
  NS_IMETHOD_(nsISVGTextFrame *) GetTextFrame();
  NS_IMETHOD_(PRBool) GetAbsolutePositionAdjustmentX(float &x, PRUint32 charNum);
  NS_IMETHOD_(PRBool) GetAbsolutePositionAdjustmentY(float &y, PRUint32 charNum);
  NS_IMETHOD_(PRBool) GetRelativePositionAdjustmentX(float &dx, PRUint32 charNum);
  NS_IMETHOD_(PRBool) GetRelativePositionAdjustmentY(float &dy, PRUint32 charNum);
  
  // nsISVGGlyphFragmentNode interface:
  NS_IMETHOD_(nsISVGGlyphFragmentLeaf *) GetFirstGlyphFragment();
  NS_IMETHOD_(nsISVGGlyphFragmentLeaf *) GetNextGlyphFragment();
  NS_IMETHOD_(PRUint32) BuildGlyphFragmentTree(PRUint32 charNum, PRBool lastBranch);
  NS_IMETHOD_(void) NotifyMetricsSuspended();
  NS_IMETHOD_(void) NotifyMetricsUnsuspended();
  NS_IMETHOD_(void) NotifyGlyphFragmentTreeSuspended();
  NS_IMETHOD_(void) NotifyGlyphFragmentTreeUnsuspended();

protected:
  already_AddRefed<nsIDOMSVGLengthList> GetX();
  already_AddRefed<nsIDOMSVGLengthList> GetY();
  nsISVGGlyphFragmentNode *GetFirstGlyphFragmentChildNode();
  nsISVGGlyphFragmentNode *GetNextGlyphFragmentChildNode(nsISVGGlyphFragmentNode*node);
  
private:
  PRUint32 mCharOffset; // index of first character of this node relative to the enclosing <text>-element
  PRBool mFragmentTreeDirty; 
  
};

//----------------------------------------------------------------------
// Implementation

nsresult
NS_NewSVGTSpanFrame(nsIPresShell* aPresShell, nsIContent* aContent,
                    nsIFrame* parentFrame, nsIFrame** aNewFrame)
{
  *aNewFrame = nsnull;

  NS_ASSERTION(parentFrame, "null parent");
  nsISVGTextFrame *text_container;
  parentFrame->QueryInterface(NS_GET_IID(nsISVGTextFrame), (void**)&text_container);
  if (!text_container) {
    NS_ERROR("trying to construct an SVGTSpanFrame for an invalid container");
    return NS_ERROR_FAILURE;
  }
  
  nsCOMPtr<nsIDOMSVGTSpanElement> tspan_elem = do_QueryInterface(aContent);
  if (!tspan_elem) {
    NS_ERROR("Trying to construct an SVGTSpanFrame for a "
             "content element that doesn't support the right interfaces");
    return NS_ERROR_FAILURE;
  }
  
  nsSVGTSpanFrame* it = new (aPresShell) nsSVGTSpanFrame;
  if (nsnull == it)
    return NS_ERROR_OUT_OF_MEMORY;

  *aNewFrame = it;
  
  return NS_OK;
}

nsSVGTSpanFrame::nsSVGTSpanFrame()
    : mCharOffset(0), mFragmentTreeDirty(PR_FALSE)
{
}

nsSVGTSpanFrame::~nsSVGTSpanFrame()
{
  // clean up our listener refs:
  {
    nsCOMPtr<nsIDOMSVGLengthList> lengthList = GetX();
    NS_REMOVE_SVGVALUE_OBSERVER(lengthList);
  }

  {
    nsCOMPtr<nsIDOMSVGLengthList> lengthList = GetY();
    NS_REMOVE_SVGVALUE_OBSERVER(lengthList);
  }
}

nsresult nsSVGTSpanFrame::Init()
{
  // set us up as a listener for various <tspan>-properties: 
  {
    nsCOMPtr<nsIDOMSVGLengthList> lengthList = GetX();
    NS_ADD_SVGVALUE_OBSERVER(lengthList);
  }

  {
    nsCOMPtr<nsIDOMSVGLengthList> lengthList = GetY();
    NS_ADD_SVGVALUE_OBSERVER(lengthList);
  }

  return NS_OK;
}

//----------------------------------------------------------------------
// nsISupports methods

NS_INTERFACE_MAP_BEGIN(nsSVGTSpanFrame)
  NS_INTERFACE_MAP_ENTRY(nsISVGTextContainerFrame)
  NS_INTERFACE_MAP_ENTRY(nsISVGGlyphFragmentNode)
  NS_INTERFACE_MAP_ENTRY(nsISVGContainerFrame)
  NS_INTERFACE_MAP_ENTRY(nsISVGChildFrame)
  NS_INTERFACE_MAP_ENTRY(nsISupportsWeakReference)
  NS_INTERFACE_MAP_ENTRY(nsISVGValueObserver)
NS_INTERFACE_MAP_END_INHERITING(nsSVGTSpanFrameBase)


//----------------------------------------------------------------------
// nsIFrame methods
NS_IMETHODIMP
nsSVGTSpanFrame::Init(nsIPresContext*  aPresContext,
                      nsIContent*      aContent,
                      nsIFrame*        aParent,
                      nsStyleContext*  aContext,
                      nsIFrame*        aPrevInFlow)
{
  nsresult rv;
  rv = nsSVGTSpanFrameBase::Init(aPresContext, aContent, aParent,
                                 aContext, aPrevInFlow);

  Init();
  
  return rv;
}

NS_IMETHODIMP
nsSVGTSpanFrame::AppendFrames(nsIPresContext* aPresContext,
                              nsIPresShell&   aPresShell,
                              nsIAtom*        aListName,
                              nsIFrame*       aFrameList)
{
  // append == insert at end:
  return InsertFrames(aPresContext, aPresShell, aListName,
                      mFrames.LastChild(), aFrameList);  
}

NS_IMETHODIMP
nsSVGTSpanFrame::InsertFrames(nsIPresContext* aPresContext,
                              nsIPresShell&   aPresShell,
                              nsIAtom*        aListName,
                              nsIFrame*       aPrevFrame,
                              nsIFrame*       aFrameList)
{
  // memorize last new frame
  nsIFrame* lastNewFrame = nsnull;
  {
    nsFrameList tmpList(aFrameList);
    lastNewFrame = tmpList.LastChild();
  }
  
  // Insert the new frames
  mFrames.InsertFrames(this, aPrevFrame, aFrameList);

  // call InitialUpdate() on all new frames:
  nsIFrame* kid = aFrameList;
  nsIFrame* end = nsnull;
  if (lastNewFrame)
    end = lastNewFrame->GetNextSibling();
  
  while (kid != end) {
    nsISVGChildFrame* SVGFrame=nsnull;
    kid->QueryInterface(NS_GET_IID(nsISVGChildFrame),(void**)&SVGFrame);
    if (SVGFrame) {
      SVGFrame->InitialUpdate(); 
    }
    kid = kid->GetNextSibling();
  }
  
  return NS_OK;
}

NS_IMETHODIMP
nsSVGTSpanFrame::RemoveFrame(nsIPresContext* aPresContext,
                             nsIPresShell&   aPresShell,
                             nsIAtom*        aListName,
                             nsIFrame*       aOldFrame)
{
  nsCOMPtr<nsISVGRendererRegion> dirty_region;

  nsISVGChildFrame* SVGFrame=nsnull;
  aOldFrame->QueryInterface(NS_GET_IID(nsISVGChildFrame),(void**)&SVGFrame);

  if (SVGFrame)
    dirty_region = SVGFrame->GetCoveredRegion();
  
  PRBool result = mFrames.DestroyFrame(aPresContext, aOldFrame);

  nsISVGOuterSVGFrame* outerSVGFrame = GetOuterSVGFrame();
  NS_ASSERTION(outerSVGFrame, "no outer svg frame");

  if (SVGFrame && outerSVGFrame) {
    // XXX We need to rebuild the fragment tree starting from the
    // removed frame. Let's just rebuild the whole tree for now
    outerSVGFrame->SuspendRedraw();
    mFragmentTreeDirty = PR_TRUE;
    
    if (dirty_region) {
      outerSVGFrame->InvalidateRegion(dirty_region, PR_FALSE);
    }

    outerSVGFrame->UnsuspendRedraw();
  }
  
  NS_ASSERTION(result, "didn't find frame to delete");
  return result ? NS_OK : NS_ERROR_FAILURE;
}

NS_IMETHODIMP
nsSVGTSpanFrame::ReplaceFrame(nsIPresContext* aPresContext,
                              nsIPresShell&   aPresShell,
                              nsIAtom*        aListName,
                              nsIFrame*       aOldFrame,
                              nsIFrame*       aNewFrame)
{
  NS_NOTYETIMPLEMENTED("write me!");
  return NS_ERROR_UNEXPECTED;
}

//----------------------------------------------------------------------
// nsISVGValueObserver methods:

NS_IMETHODIMP
nsSVGTSpanFrame::WillModifySVGObservable(nsISVGValue* observable)
{
  return NS_OK;
}


NS_IMETHODIMP
nsSVGTSpanFrame::DidModifySVGObservable (nsISVGValue* observable)
{
  
  nsIFrame* kid = mFrames.FirstChild();
  while (kid) {
    nsISVGChildFrame* SVGFrame=0;
    kid->QueryInterface(NS_GET_IID(nsISVGChildFrame),(void**)&SVGFrame);
    if (SVGFrame)
      SVGFrame->NotifyCTMChanged(); // XXX
    kid = kid->GetNextSibling();
  }  
  return NS_OK;
}


//----------------------------------------------------------------------
// nsISVGChildFrame methods

NS_IMETHODIMP
nsSVGTSpanFrame::Paint(nsISVGRendererCanvas* canvas, const nsRect& dirtyRectTwips)
{
#ifdef DEBUG
//  printf("nsSVGTSpanFrame(%p)::Paint\n", this);
#endif

  nsIFrame* kid = mFrames.FirstChild();
  while (kid) {
    nsISVGChildFrame* SVGFrame=0;
    kid->QueryInterface(NS_GET_IID(nsISVGChildFrame),(void**)&SVGFrame);
    if (SVGFrame)
      SVGFrame->Paint(canvas, dirtyRectTwips);
    kid = kid->GetNextSibling();
  }

  return NS_OK;
}

NS_IMETHODIMP
nsSVGTSpanFrame::GetFrameForPoint(float x, float y, nsIFrame** hit)
{
#ifdef DEBUG
//  printf("nsSVGTSpanFrame(%p)::GetFrameForPoint\n", this);
#endif
  *hit = nsnull;
  nsIFrame* kid = mFrames.FirstChild();
  while (kid) {
    nsISVGChildFrame* SVGFrame=0;
    kid->QueryInterface(NS_GET_IID(nsISVGChildFrame),(void**)&SVGFrame);
    if (SVGFrame) {
      nsIFrame* temp=nsnull;
      nsresult rv = SVGFrame->GetFrameForPoint(x, y, &temp);
      if (NS_SUCCEEDED(rv) && temp) {
        *hit = temp;
        // return NS_OK; can't return. we need reverse order but only
        // have a singly linked list...
      }
    }
    kid = kid->GetNextSibling();
  }
  
  return *hit ? NS_OK : NS_ERROR_FAILURE;
}

NS_IMETHODIMP_(already_AddRefed<nsISVGRendererRegion>)
nsSVGTSpanFrame::GetCoveredRegion()
{
  nsISVGRendererRegion *accu_region=nsnull;
  
  nsIFrame* kid = mFrames.FirstChild();
  while (kid) {
    nsISVGChildFrame* SVGFrame=0;
    kid->QueryInterface(NS_GET_IID(nsISVGChildFrame),(void**)&SVGFrame);
    if (SVGFrame) {
      nsCOMPtr<nsISVGRendererRegion> dirty_region = SVGFrame->GetCoveredRegion();
      if (accu_region) {
        nsCOMPtr<nsISVGRendererRegion> temp = dont_AddRef(accu_region);
        dirty_region->Combine(temp, &accu_region);
      }
      else {
        accu_region = dirty_region;
        NS_IF_ADDREF(accu_region);
      }
    }
    kid = kid->GetNextSibling();
  }
  
  return accu_region;
}

NS_IMETHODIMP
nsSVGTSpanFrame::InitialUpdate()
{
  nsIFrame* kid = mFrames.FirstChild();
  while (kid) {
    nsISVGChildFrame* SVGFrame=0;
    kid->QueryInterface(NS_GET_IID(nsISVGChildFrame),(void**)&SVGFrame);
    if (SVGFrame) {
      SVGFrame->InitialUpdate();
    }
    kid = kid->GetNextSibling();
  }
  return NS_OK;
}  

NS_IMETHODIMP
nsSVGTSpanFrame::NotifyCTMChanged()
{
  nsIFrame* kid = mFrames.FirstChild();
  while (kid) {
    nsISVGChildFrame* SVGFrame=0;
    kid->QueryInterface(NS_GET_IID(nsISVGChildFrame),(void**)&SVGFrame);
    if (SVGFrame) {
      SVGFrame->NotifyCTMChanged();
    }
    kid = kid->GetNextSibling();
  }
  return NS_OK;
}

NS_IMETHODIMP
nsSVGTSpanFrame::NotifyRedrawSuspended()
{
  nsIFrame* kid = mFrames.FirstChild();
  while (kid) {
    nsISVGChildFrame* SVGFrame=0;
    kid->QueryInterface(NS_GET_IID(nsISVGChildFrame),(void**)&SVGFrame);
    if (SVGFrame) {
      SVGFrame->NotifyRedrawSuspended();
    }
    kid = kid->GetNextSibling();
  }
  return NS_OK;
}

NS_IMETHODIMP
nsSVGTSpanFrame::NotifyRedrawUnsuspended()
{
  nsIFrame* kid = mFrames.FirstChild();
  while (kid) {
    nsISVGChildFrame* SVGFrame=0;
    kid->QueryInterface(NS_GET_IID(nsISVGChildFrame),(void**)&SVGFrame);
    if (SVGFrame) {
      SVGFrame->NotifyRedrawUnsuspended();
    }
    kid = kid->GetNextSibling();
  }
  return NS_OK;
}

NS_IMETHODIMP
nsSVGTSpanFrame::GetBBox(nsIDOMSVGRect **_retval)
{
  *_retval = nsnull;
  
  // iterate over all children and accumulate the bounding rect:
  // this relies on the fact that children of <text> elements can't
  // have individual transforms
  
  float x1=0.0f, y1=0.0f, x2=0.0f, y2=0.0f;
  PRBool bFirst=PR_TRUE;
  nsIFrame* kid = mFrames.FirstChild();
  while (kid) {
    nsISVGChildFrame* SVGFrame=0;
    kid->QueryInterface(NS_GET_IID(nsISVGChildFrame),(void**)&SVGFrame);
    if (SVGFrame) {
      nsCOMPtr<nsIDOMSVGRect> r;
      SVGFrame->GetBBox(getter_AddRefs(r));
      NS_ASSERTION(r, "no bounding box");
      if (!r) continue;

      float x,y,w,h;
      r->GetX(&x);
      r->GetY(&y);
      r->GetWidth(&w);
      r->GetHeight(&h);
      
      if (bFirst) {
        bFirst = PR_FALSE;
        x1 = x;
        y1 = y;
        x2 = x+w;
        y2 = y+h;
      }
      else {
        if (x<x1) x1 = x;
        if (x+w>x2) x2 = x+w;
        if (y<y1) y1 = y;
        if (y+h>y2) y2 = y+h;
      }
    }
    kid = kid->GetNextSibling();
  }

  nsISVGOuterSVGFrame *outerSVGFrame = GetOuterSVGFrame();
  if (!outerSVGFrame) {
    NS_ERROR("null outerSVGFrame");
    return NS_ERROR_FAILURE;
  }

  outerSVGFrame->CreateSVGRect(_retval);

  (*_retval)->SetWidth(x2-x1);
  (*_retval)->SetHeight(y2-y1);
  (*_retval)->SetX(x1);
  (*_retval)->SetY(y1);

  return NS_OK;  
}

//----------------------------------------------------------------------
// nsISVGContainerFrame methods:

NS_IMETHODIMP_(nsISVGOuterSVGFrame *)
nsSVGTSpanFrame::GetOuterSVGFrame()
{
  NS_ASSERTION(mParent, "null parent");
  
  nsISVGContainerFrame *containerFrame;
  mParent->QueryInterface(NS_GET_IID(nsISVGContainerFrame), (void**)&containerFrame);
  if (!containerFrame) {
    NS_ERROR("invalid container");
    return nsnull;
  }

  return containerFrame->GetOuterSVGFrame();  
}

//----------------------------------------------------------------------
// nsISVGTextContainerFrame methods:

NS_IMETHODIMP_(nsISVGTextFrame *)
nsSVGTSpanFrame::GetTextFrame()
{
  NS_ASSERTION(mParent, "null parent");
  nsISVGTextContainerFrame *containerFrame;
  mParent->QueryInterface(NS_GET_IID(nsISVGTextContainerFrame), (void**)&containerFrame);
  if (!containerFrame) {
    return nsnull;
  }

  return containerFrame->GetTextFrame();  
}

NS_IMETHODIMP_(PRBool)
nsSVGTSpanFrame::GetAbsolutePositionAdjustmentX(float &x, PRUint32 charNum)
{
  return PR_FALSE;  
}

NS_IMETHODIMP_(PRBool)
nsSVGTSpanFrame::GetAbsolutePositionAdjustmentY(float &y, PRUint32 charNum)
{
  return PR_FALSE;    
}

NS_IMETHODIMP_(PRBool)
nsSVGTSpanFrame::GetRelativePositionAdjustmentX(float &dx, PRUint32 charNum)
{
  return PR_FALSE;    
}

NS_IMETHODIMP_(PRBool)
nsSVGTSpanFrame::GetRelativePositionAdjustmentY(float &dy, PRUint32 charNum)
{
  return PR_FALSE;    
}


//----------------------------------------------------------------------
// nsISVGGlyphFragmentNode methods:

NS_IMETHODIMP_(nsISVGGlyphFragmentLeaf *)
nsSVGTSpanFrame::GetFirstGlyphFragment()
{
  // try children first:
  nsIFrame* kid = mFrames.FirstChild();
  while (kid) {
    nsISVGGlyphFragmentNode *node = nsnull;
    kid->QueryInterface(NS_GET_IID(nsISVGGlyphFragmentNode),(void**)&node);
    if (node)
      return node->GetFirstGlyphFragment();
    kid = kid->GetNextSibling();
  }

  // nope. try siblings:
  return GetNextGlyphFragment();

}

NS_IMETHODIMP_(nsISVGGlyphFragmentLeaf *)
nsSVGTSpanFrame::GetNextGlyphFragment()
{
  nsIFrame* sibling = mNextSibling;
  while (sibling) {
    nsISVGGlyphFragmentNode *node = nsnull;
    sibling->QueryInterface(NS_GET_IID(nsISVGGlyphFragmentNode), (void**)&node);
    if (node)
      return node->GetFirstGlyphFragment();
    sibling = sibling->GetNextSibling();
  }

  // no more siblings. go back up the tree.
  
  NS_ASSERTION(mParent, "null parent");
  nsISVGGlyphFragmentNode *node = nsnull;
  mParent->QueryInterface(NS_GET_IID(nsISVGGlyphFragmentNode), (void**)&node);
  return node ? node->GetNextGlyphFragment() : nsnull;
}

NS_IMETHODIMP_(PRUint32)
nsSVGTSpanFrame::BuildGlyphFragmentTree(PRUint32 charNum, PRBool lastBranch)
{
  mCharOffset = charNum;

  // init children:
  nsISVGGlyphFragmentNode* node = GetFirstGlyphFragmentChildNode();
  nsISVGGlyphFragmentNode* next;
  while (node) {
    next = GetNextGlyphFragmentChildNode(node);
    charNum = node->BuildGlyphFragmentTree(charNum, lastBranch && !next);
    node = next;
  }
  
  return charNum;
}


NS_IMETHODIMP_(void)
nsSVGTSpanFrame::NotifyMetricsSuspended()
{
  nsIFrame* kid = mFrames.FirstChild();
  while (kid) {
    nsISVGGlyphFragmentNode *node = nsnull;
    kid->QueryInterface(NS_GET_IID(nsISVGGlyphFragmentNode), (void**)&node);
    if (node)
      node->NotifyMetricsSuspended();
    kid = kid->GetNextSibling();
  }
}

NS_IMETHODIMP_(void)
nsSVGTSpanFrame::NotifyMetricsUnsuspended()
{
  nsIFrame* kid = mFrames.FirstChild();
  while (kid) {
    nsISVGGlyphFragmentNode *node = nsnull;
    kid->QueryInterface(NS_GET_IID(nsISVGGlyphFragmentNode), (void**)&node);
    if (node)
      node->NotifyMetricsUnsuspended();
    kid = kid->GetNextSibling();
  }
}

NS_IMETHODIMP_(void)
nsSVGTSpanFrame::NotifyGlyphFragmentTreeSuspended()
{
  nsIFrame* kid = mFrames.FirstChild();
  while (kid) {
    nsISVGGlyphFragmentNode *node = nsnull;
    kid->QueryInterface(NS_GET_IID(nsISVGGlyphFragmentNode), (void**)&node);
    if (node)
      node->NotifyGlyphFragmentTreeSuspended();
    kid = kid->GetNextSibling();
  }
}

NS_IMETHODIMP_(void)
nsSVGTSpanFrame::NotifyGlyphFragmentTreeUnsuspended()
{
  if (mFragmentTreeDirty) {
    nsISVGTextFrame* text_frame = GetTextFrame();
    NS_ASSERTION(text_frame, "null text frame");
    if (text_frame)
      text_frame->NotifyGlyphFragmentTreeChange(this);
    mFragmentTreeDirty = PR_FALSE;
  }    
  
  nsIFrame* kid = mFrames.FirstChild();
  while (kid) {
    nsISVGGlyphFragmentNode *node = nsnull;
    kid->QueryInterface(NS_GET_IID(nsISVGGlyphFragmentNode), (void**)&node);
    if (node)
      node->NotifyGlyphFragmentTreeUnsuspended();
    kid = kid->GetNextSibling();
  }
}


//----------------------------------------------------------------------
//

already_AddRefed<nsIDOMSVGLengthList>
nsSVGTSpanFrame::GetX()
{
  nsCOMPtr<nsIDOMSVGTextPositioningElement> tpElement = do_QueryInterface(mContent);
  NS_ASSERTION(tpElement, "wrong content element");

  nsCOMPtr<nsIDOMSVGAnimatedLengthList> animLengthList;
  tpElement->GetX(getter_AddRefs(animLengthList));
  nsIDOMSVGLengthList *retval;
  animLengthList->GetAnimVal(&retval);
  return retval;
}

already_AddRefed<nsIDOMSVGLengthList>
nsSVGTSpanFrame::GetY()
{
  nsCOMPtr<nsIDOMSVGTextPositioningElement> tpElement = do_QueryInterface(mContent);
  NS_ASSERTION(tpElement, "wrong content element");

  nsCOMPtr<nsIDOMSVGAnimatedLengthList> animLengthList;
  tpElement->GetY(getter_AddRefs(animLengthList));
  nsIDOMSVGLengthList *retval;
  animLengthList->GetAnimVal(&retval);
  return retval;
}

nsISVGGlyphFragmentNode *
nsSVGTSpanFrame::GetFirstGlyphFragmentChildNode()
{
  nsISVGGlyphFragmentNode* retval = nsnull;
  nsIFrame* frame = mFrames.FirstChild();
  while (frame) {
    frame->QueryInterface(NS_GET_IID(nsISVGGlyphFragmentNode),(void**)&retval);
    if (retval) break;
    frame = frame->GetNextSibling();
  }
  return retval;
}

nsISVGGlyphFragmentNode *
nsSVGTSpanFrame::GetNextGlyphFragmentChildNode(nsISVGGlyphFragmentNode*node)
{
  nsISVGGlyphFragmentNode* retval = nsnull;
  nsIFrame* frame = nsnull;
  node->QueryInterface(NS_GET_IID(nsIFrame), (void**)&frame);
  NS_ASSERTION(frame, "interface not implemented");
  frame = frame->GetNextSibling();
  while (frame) {
    frame->QueryInterface(NS_GET_IID(nsISVGGlyphFragmentNode),(void**)&retval);
    if (retval) break;
    frame = frame->GetNextSibling();
  }
  return retval;
}