gecko-dev/layout/generic/nsSplittableFrame.cpp

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#include "nsSplittableFrame.h"
#include "nsIContent.h"
#include "nsIPresContext.h"
#include "nsIStyleContext.h"
#include "nsISizeOfHandler.h"

NS_IMETHODIMP
nsSplittableFrame::Init(nsIPresContext*  aPresContext,
                        nsIContent*      aContent,
                        nsIFrame*        aParent,
                        nsIStyleContext* aContext,
                        nsIFrame*        aPrevInFlow)
{
  nsresult  rv;
  
  rv = nsFrame::Init(aPresContext, aContent, aParent, aContext, aPrevInFlow);

  if (aPrevInFlow) {
    // Hook the frame into the flow
    mPrevInFlow = aPrevInFlow;
    aPrevInFlow->SetNextInFlow(this);
  }

  return rv;
}

NS_IMETHODIMP
nsSplittableFrame::IsSplittable(nsSplittableType& aIsSplittable) const
{
  aIsSplittable = NS_FRAME_SPLITTABLE;
  return NS_OK;
}

NS_METHOD nsSplittableFrame::GetPrevInFlow(nsIFrame** aPrevInFlow) const
{
  *aPrevInFlow = mPrevInFlow;
  return NS_OK;
}

NS_METHOD nsSplittableFrame::SetPrevInFlow(nsIFrame* aFrame)
{
  mPrevInFlow = aFrame;
  return NS_OK;
}

NS_METHOD nsSplittableFrame::GetNextInFlow(nsIFrame** aNextInFlow) const
{
  *aNextInFlow = mNextInFlow;
  return NS_OK;
}

NS_METHOD nsSplittableFrame::SetNextInFlow(nsIFrame* aFrame)
{
  mNextInFlow = aFrame;
  return NS_OK;
}

nsIFrame* nsSplittableFrame::GetFirstInFlow() const
{
  nsSplittableFrame* firstInFlow;
  nsSplittableFrame* prevInFlow = (nsSplittableFrame*)this;
  while (nsnull!=prevInFlow)  {
    firstInFlow = prevInFlow;
    prevInFlow = (nsSplittableFrame*)firstInFlow->mPrevInFlow;
  }
  NS_POSTCONDITION(nsnull!=firstInFlow, "illegal state in flow chain.");
  return firstInFlow;
}

nsIFrame* nsSplittableFrame::GetLastInFlow() const
{
  nsSplittableFrame* lastInFlow;
  nsSplittableFrame* nextInFlow = (nsSplittableFrame*)this;
  while (nsnull!=nextInFlow)  {
    lastInFlow = nextInFlow;
    nextInFlow = (nsSplittableFrame*)lastInFlow->mNextInFlow;
  }
  NS_POSTCONDITION(nsnull!=lastInFlow, "illegal state in flow chain.");
  return lastInFlow;
}

// Remove this frame from the flow. Connects prev in flow and next in flow
void
nsSplittableFrame::RemoveFromFlow(nsIFrame* aFrame)
{
  nsIFrame* prevInFlow;
  nsIFrame* nextInFlow;

  aFrame->GetPrevInFlow(&prevInFlow);
  aFrame->GetNextInFlow(&nextInFlow);

  if (prevInFlow) {
    prevInFlow->SetNextInFlow(nextInFlow);
  }

  if (nextInFlow) {
    nextInFlow->SetPrevInFlow(prevInFlow);
  }

  aFrame->SetPrevInFlow(nsnull);
  aFrame->SetNextInFlow(nsnull);
}

// Detach from previous frame in flow
void
nsSplittableFrame::BreakFromPrevFlow(nsIFrame* aFrame)
{
  nsIFrame* prevInFlow;

  aFrame->GetPrevInFlow(&prevInFlow);
  if (prevInFlow) {
    prevInFlow->SetNextInFlow(nsnull);
    aFrame->SetPrevInFlow(nsnull);
  }
}

nsIFrame * nsSplittableFrame::GetPrevInFlow() 
{
  return mPrevInFlow;
}

nsIFrame * nsSplittableFrame::GetNextInFlow()
{
   return mNextInFlow;
} 

#ifdef DEBUG
void
nsSplittableFrame::DumpBaseRegressionData(nsIPresContext* aPresContext, FILE* out, PRInt32 aIndent, PRBool aIncludeStyleData)
{
  nsFrame::DumpBaseRegressionData(aPresContext, out, aIndent, aIncludeStyleData);
  if (nsnull != mNextInFlow) {
    IndentBy(out, aIndent);
    fprintf(out, "<next-in-flow va=\"%ld\"/>\n", PRUptrdiff(mNextInFlow));
  }
  if (nsnull != mPrevInFlow) {
    IndentBy(out, aIndent);
    fprintf(out, "<prev-in-flow va=\"%ld\"/>\n", PRUptrdiff(mPrevInFlow));
  }

}

NS_IMETHODIMP
nsSplittableFrame::SizeOf(nsISizeOfHandler* aHandler, PRUint32* aResult) const
{
  if (!aResult) {
    return NS_ERROR_NULL_POINTER;
  }
  *aResult = sizeof(*this);
  return NS_OK;
}
#endif