Part of table dialog work: new method needed to convert to TH from TD and vice versa. b=20973. r=jfrancis

editor/idl/nsIEditorShell.idl

@@ -334,6 +334,18 @@ interface nsIEditorShell : nsISupports
   void DeleteTableCellContents();
   void DeleteTableRow(in PRInt32 number);
   void DeleteTableColumn(in PRInt32 number);
+
+
+  /** Create a new TD or TH element, the opposite type of the supplied aSourceCell
+    *   1. Copy all attributes from sourceCell to the new cell
+    *   2. Move all contents of sourceCell to the new cell
+    *   3. Replace sourceCell in the table with the new cell
+    *
+    *  sourceCell   The cell to be replaced
+    *  returns      The new cell that replaces sourceCell
+    */
+  nsIDOMElement SwitchTableCellHeaderType(in nsIDOMElement sourceCell);
+
   /** Merges contents of all selected cells
     * for selected cells that are adjacent,
     * this will result in a larger cell with appropriate 
@@ -392,19 +404,21 @@ interface nsIEditorShell : nsISupports
     */
   PRInt32 GetTableRowCount(in nsIDOMElement tableElement);
 
-  /* Get the number of columns in a table from the layout's cellmap
+  /** Get the number of columns in a table from the layout's cellmap
     * If tableElement is null, it will try to find enclosing table of selection anchor
     */
   PRInt32 GetTableColumnCount(in nsIDOMElement tableElement);
 
-  /* Get cell at a location in the layout's cellmap
-     returns null when past last cell in a row or column */
-  /* Get a cell and associated data from the layout frame  based on cell map coordinates (0 index) */
+  /** Get cell at a location in the layout's cellmap
+    * returns null when past last cell in a row or column
+    * Get a cell and associated data from the layout frame  based on cell map coordinates (0 index)
+    */
   nsIDOMElement GetCellAt(in nsIDOMElement tableElement, in PRInt32 rowIndex, in PRInt32 colIndex);
-  /* Get cell at a location in the layout's cellmap with associated data 
-     returns null when past last cell in a row or column 
-     Note that rowSpan and/or colSpan may be 0 (for extending across entire table),
-     so actualRowSpan and actualColSpan are the real number of cells spanned
+
+  /** Get cell at a location in the layout's cellmap with associated data 
+    * returns null when past last cell in a row or column 
+    * Note that rowSpan and/or colSpan may be 0 (for extending across entire table),
+    * so actualRowSpan and actualColSpan are the real number of cells spanned
     */
   nsIDOMElement GetCellDataAt(in nsIDOMElement tableElement, in PRInt32 rowIndex, in PRInt32 colIndex,
                               out PRInt32 startRowIndex, out PRInt32 startColIndex,
@@ -412,12 +426,12 @@ interface nsIEditorShell : nsISupports
                               out PRInt32 actualRowSpan, out PRInt32 actualColSpan, 
                               out boolean isSelected);
   
-  /* Get the first row element in a table 
-     tableElement may be a table or any child element a table
+  /** Get the first row element in a table 
+    * tableElement may be a table or any child element a table
     */
   nsIDOMElement GetFirstRow(in nsIDOMElement tableElement);
 
-  /* Get the next row element in a table after currentRow 
+  /** Get the next row element in a table after currentRow 
     * currentRow may be a row or any child element of a row
     */
   nsIDOMElement GetNextRow(in nsIDOMElement currentRow);

editor/public/nsITableEditor.h

@@ -100,6 +100,16 @@ public:
   NS_IMETHOD SelectTable()=0;
   NS_IMETHOD SelectAllTableCells()=0;
 
+  /** Create a new TD or TH element, the opposite type of the supplied aSourceCell
+    *   1. Copy all attributes from aSourceCell to the new cell
+    *   2. Move all contents of aSourceCell to the new cell
+    *   3. Replace aSourceCell in the table with the new cell
+    *
+    *  @param aSourceCell   The cell to be replaced
+    *  @param aNewCell      The new cell that replaces aSourceCell
+    */
+  NS_IMETHOD SwitchTableCellHeaderType(nsIDOMElement *aSourceCell, nsIDOMElement **aNewCell)=0;
+
   /** Merges contents of all selected cells
     * for selected cells that are adjacent,
     * this will result in a larger cell with appropriate