Merge pull request #41 from bvp/master

getLastCellNum implementation

Author: monitorjbl

src/main/java/com/monitorjbl/xlsx/impl/StreamingRow.java

@@ -66,6 +66,17 @@ public Cell getCell(int cellnum) {
     return cellMap.get(cellnum);
   }
 
+  /**
+   * Gets the index of the last cell contained in this row <b>PLUS ONE</b>.
+   * 
+   * @return short representing the last logical cell in the row <b>PLUS ONE</b>,
+   *   or -1 if the row does not contain any cells.
+   */
+  @Override
+  public short getLastCellNum() {
+    return (short) (cellMap.size() == 0 ? -1 : cellMap.size() + 1);
+  }
+
   /* Not supported */
 
   /**
@@ -116,14 +127,6 @@ public short getFirstCellNum() {
     throw new NotSupportedException();
   }
 
-  /**
-   * Not supported
-   */
-  @Override
-  public short getLastCellNum() {
-    throw new NotSupportedException();
-  }
-
   /**
    * Not supported
    */
@@ -220,4 +223,4 @@ public int getOutlineLevel() {
     throw new NotSupportedException();
   }
 
-}
+}