Mozilla/mozilla/extensions/schema-validation/src/nsDOMUtils.h

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 * for the specific language governing rights and limitations under the
 * License.
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 * The Initial Developer of the Original Code is
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 * Portions created by the Initial Developer are Copyright (C) 2001
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 * Contributor(s):
 *   Vidur Apparao <vidur@netscape.com> (original author)
 *
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#ifndef _nsDOMUtils_h__
#define _nsDOMUtils_h__

// content includes
#include "nsIContent.h"
#include "nsIDOMElement.h"
#include "nsIDOMNode.h"
#include "nsIDOMNodeList.h"

// string includes
#include "nsStringAPI.h"

// collection includes
#include "nsVoidArray.h"

////////////////////////////////////////////////////////////
//
// nsChildElementIterator
//
////////////////////////////////////////////////////////////

class nsChildElementIterator {
private:
  nsCOMPtr<nsIDOMNodeList> mNodeList;
  PRUint32 mIndex;
  PRUint32 mLength;
  nsString mNamespace;
  const char** mNamespaceArray;
  PRUint32 mNumNamespaces;

public:
  nsChildElementIterator(nsIDOMElement* aParent) :
    mIndex(0), mLength(0), mNumNamespaces(0)
  {
    SetElement(aParent);
  }
  
  nsChildElementIterator(nsIDOMElement* aParent,
                         const nsAString& aNamespace) :
    mIndex(0), mLength(0), mNamespace(aNamespace), mNumNamespaces(0)
  {
    SetElement(aParent);
  }

  nsChildElementIterator(nsIDOMElement* aParent,
                         const char** aNamespaceArray,
                         PRUint32 aNumNamespaces) :
    mIndex(0), mLength(0), mNamespaceArray(aNamespaceArray),
    mNumNamespaces(aNumNamespaces)
  {
    SetElement(aParent);
  }

  ~nsChildElementIterator() {}

  void SetElement(nsIDOMElement* aParent)
  {
    aParent->GetChildNodes(getter_AddRefs(mNodeList));
    if (mNodeList) {
      mNodeList->GetLength(&mLength);
      // if we change the element, reset the index
      mIndex = 0;
    }
  }

  PRUint32 GetCurrentIndex() { return mIndex; }

  void Reset(PRUint32 aIndex=0) { mIndex = aIndex; }

  PRBool HasChildNodes() { return mLength; }

  nsresult GetNextChild(nsIDOMElement** aChildElement,
                        nsIAtom** aElementName)
  {
    *aChildElement = nsnull;
    
    if (!mNodeList) {
      return NS_ERROR_FAILURE;
    }

    nsCOMPtr<nsIDOMNode> child;
    while (mIndex < mLength) {
      mNodeList->Item(mIndex++, getter_AddRefs(child));
      nsCOMPtr<nsIDOMElement> childElement(do_QueryInterface(child));
      if (!childElement) {
        continue;
      }
      
      // Confirm that the element is an element of the specified namespace
      nsAutoString namespaceURI;
      childElement->GetNamespaceURI(namespaceURI);
      if (!mNamespace.IsEmpty()) {
        if (!namespaceURI.Equals(mNamespace)) {
          continue;
        }
      }
      else if (mNumNamespaces) {
        PRUint32 i;
        for (i = 0; i < mNumNamespaces; i++) {
          if (!namespaceURI.Equals(NS_ConvertASCIItoUTF16(mNamespaceArray[i]))) {
            continue;
          }
        }
      }
      
      nsCOMPtr<nsIContent> content(do_QueryInterface(childElement));
      NS_ASSERTION(content, "Element is not content");
      if (!content) {
        return NS_ERROR_FAILURE;
      }
      
      NS_ADDREF(*aElementName = content->Tag());

      *aChildElement = childElement;
      NS_ADDREF(*aChildElement);
      break;
    }
    
    return NS_OK;
  }
};

#endif // _nsDOMUtils_h__