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#include "InsertElementTxn.h"
#include "nsISelection.h"
#include "nsIContent.h"
#include "nsIDOMNodeList.h"
#include "nsReadableUtils.h"

#ifdef NS_DEBUG
static PRBool gNoisy = PR_FALSE;
#endif


InsertElementTxn::InsertElementTxn()
  : EditTxn()
{
}

NS_IMETHODIMP InsertElementTxn::Init(nsIDOMNode *aNode,
                                     nsIDOMNode *aParent,
                                     PRInt32     aOffset,
                                     nsIEditor  *aEditor)
{
  NS_ASSERTION(aNode && aParent && aEditor, "bad arg");
  if (!aNode || !aParent || !aEditor)
    return NS_ERROR_NULL_POINTER;

  mNode = do_QueryInterface(aNode);
  mParent = do_QueryInterface(aParent);
  mOffset = aOffset;
  mEditor = aEditor;
  if (!mNode || !mParent || !mEditor)
    return NS_ERROR_INVALID_ARG;
  return NS_OK;
}


InsertElementTxn::~InsertElementTxn()
{
}

NS_IMETHODIMP InsertElementTxn::DoTransaction(void)
{
#ifdef NS_DEBUG
  if (gNoisy) 
  { 
    nsCOMPtr<nsIContent>nodeAsContent = do_QueryInterface(mNode);
    nsCOMPtr<nsIContent>parentAsContent = do_QueryInterface(mParent);
    nsString namestr;
    mNode->GetNodeName(namestr);
    char* nodename = ToNewCString(namestr);
    printf("%p Do Insert Element of %p <%s> into parent %p at offset %d\n", 
           this, nodeAsContent.get(), nodename,
           parentAsContent.get(), mOffset); 
    nsMemory::Free(nodename);
  }
#endif

  if (!mNode || !mParent) return NS_ERROR_NOT_INITIALIZED;

  nsCOMPtr<nsIDOMNodeList> childNodes;
  nsresult result = mParent->GetChildNodes(getter_AddRefs(childNodes));
  if (NS_FAILED(result)) return result;
  nsCOMPtr<nsIDOMNode>refNode;
  if (childNodes)
  {
    PRUint32 count;
    childNodes->GetLength(&count);
    if (mOffset>(PRInt32)count) mOffset = count;
    // -1 is sentinel value meaning "append at end"
    if (mOffset == -1) mOffset = count;
    result = childNodes->Item(mOffset, getter_AddRefs(refNode));
    if (NS_FAILED(result)) return result; 
    // note, it's ok for mRefNode to be null.  that means append
  }

  mEditor->MarkNodeDirty(mNode);

  nsCOMPtr<nsIDOMNode> resultNode;
  result = mParent->InsertBefore(mNode, refNode, getter_AddRefs(resultNode));
  if (NS_FAILED(result)) return result;
  if (!resultNode) return NS_ERROR_NULL_POINTER;

  // only set selection to insertion point if editor gives permission
  PRBool bAdjustSelection;
  mEditor->ShouldTxnSetSelection(&bAdjustSelection);
  if (bAdjustSelection)
  {
    nsCOMPtr<nsISelection> selection;
    result = mEditor->GetSelection(getter_AddRefs(selection));
    if (NS_FAILED(result)) return result;
    if (!selection) return NS_ERROR_NULL_POINTER;
    // place the selection just after the inserted element
    selection->Collapse(mParent, mOffset+1);
  }
  else
  {
    // do nothing - dom range gravity will adjust selection
  }
  return result;
}

NS_IMETHODIMP InsertElementTxn::UndoTransaction(void)
{
#ifdef NS_DEBUG
  if (gNoisy) { printf("%p Undo Insert Element of %p into parent %p at offset %d\n", 
                       this, mNode.get(), mParent.get(), mOffset); }
#endif

  if (!mNode || !mParent) return NS_ERROR_NOT_INITIALIZED;

  nsCOMPtr<nsIDOMNode> resultNode;
  return mParent->RemoveChild(mNode, getter_AddRefs(resultNode));
}

NS_IMETHODIMP InsertElementTxn::Merge(nsITransaction *aTransaction, PRBool *aDidMerge)
{
  if (aDidMerge)
    *aDidMerge = PR_FALSE;
  return NS_OK;
}

NS_IMETHODIMP InsertElementTxn::GetTxnDescription(nsAString& aString)
{
  aString.AssignLiteral("InsertElementTxn");
  return NS_OK;
}