#include "nsIDataMatrix.h"

 #include "nsTPtrArray.h"

 #include "nsIClassInfoImpl.h"

 #include "nsCOMPtr.h"

 #include "nsAutoPtr.h"

 typedef nsTPtrArray<nsISupports> MatrixRow;

 typedef nsAutoPtr<MatrixRow> MatrixAutoRow;

 class nsWritableDataMatrix : public nsIWritableDataMatrix

 {

 public:

   NS_DECL_ISUPPORTS

   NS_DECL_NSIDATAMATRIX

   NS_DECL_NSIWRITABLEDATAMATRIX

   nsWritableDataMatrix();

   nsresult Init();

 private:

   ~nsWritableDataMatrix();

   nsTArray<MatrixAutoRow> matrix;

   PRUint32 mColumnCount;

   nsresult GetEnsuredRow(PRUint32 rowIndex, MatrixRow **row);

   void EnsureColumnCount(PRUint32 columnCount);

   void TruncateExtraColumns();

 protected:

   /* additional members */

 };

 // fb77a827-a375-49d6-a723-79b2ac66fb21

 #define NSWRITABLEDATAMATRIX_CID \

 { 0xfb77a827, 0xa375, 0x49d6, \

   { 0xa7, 0x23, 0x79, 0xb2, 0xac, 0x66, 0xfb, 0x21 } }

 #define NSWRITABLEDATAMATRIX_CONTRACTID "@mozilla.org/data-matrix;1"