if ( adapter.hasParent( ) ) return false;
	protected boolean checkTargetColumn( int sourceColumn, int destColumn )	{		// If the new position is the same as the old, then skip the operation.		int newPosn = adjustDestPosn( sourceColumn, destColumn );		if ( newPosn == -1 )			return true;		int columnCount = adapter.getColumnCount( );		if ( newPosn == 0 || newPosn == columnCount )			return true;		List originalCells = getCellsContextInfo( adapter				.getCellsUnderColumn( newPosn ) );		if ( !isRectangleArea( originalCells, 1 ) )			return false;		return true;	}