Program Listing for File strings.hpp

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/*****************************************************************************
** Ifdefs
*****************************************************************************/

#ifndef ECL_FORMATTERS_STRINGS_HPP_
#define ECL_FORMATTERS_STRINGS_HPP_

/*****************************************************************************
** Includes
*****************************************************************************/

#include <string>
#include <ecl/exceptions/standard_exception.hpp>
#include "common.hpp"
#include "macros.hpp"

/*****************************************************************************
** Namespaces
*****************************************************************************/

namespace ecl {

/*****************************************************************************
** Format Interface [String types]
*****************************************************************************/

template <>
class ecl_formatters_PUBLIC Format<std::string> {
    public:
        /******************************************
        ** C&D's
        *******************************************/
        Format(int w = -1, Alignment a = NoAlign) : width_(w),alignment_(a) {}
        virtual ~Format() {}

        /******************************************
        ** Set
        *******************************************/
        Format<std::string>& width(int w) { width_ = w; return *this; }
        Format<std::string>& align(Alignment a) { alignment_ = a;  return *this; }

        /******************************************
         * Set Format Combinations
         ******************************************/
        Format<std::string>& operator ()(int w, Alignment a);

        /******************************************
        ** Format a value
        *******************************************/
        Format<std::string>& operator() (const std::string &input_string);

        /******************************************
        ** Common format usages
        *******************************************/
        Format<std::string>& operator() (const std::string &input_string, int w);
        Format<std::string>& operator() (const std::string &input_string, int w, Alignment a);

        /******************************************
        ** Insert the formatter into a stream
        *******************************************/
        template <typename OutputStream> friend OutputStream& operator << (OutputStream& ostream, Format<std::string>& formatter);

    private:
        /******************************************
        ** Parameters
        *******************************************/
        int width_;
        Alignment alignment_;
        bool ready_to_format;
        std::string s;

        /******************************************
        ** Padding
        *******************************************/
        template <typename OutputStream> void pad(int n, OutputStream &ostream) const;
        template <typename OutputStream> void prePad(int n, OutputStream &ostream) const;
        template <typename OutputStream> void postPad(int n, OutputStream &ostream) const;

        /******************************************
        ** Formatter Functions
        *******************************************/
        template <typename OutputStream> void format(OutputStream &ostream) const;
};

/*****************************************************************************
** Implementation [Format<string>][Templates]
*****************************************************************************/

template <typename OutputStream>
void Format<std::string>::format(OutputStream &ostream) const
{
    int size = s.size();

    prePad(width_ - (size),ostream); // previously had (size+2) here...why?
    ostream << s;
    postPad(width_ - (size),ostream);
}

template <typename OutputStream>
void Format<std::string>::prePad(int n, OutputStream &ostream) const
{
    if ( n <= 0 ) { return; }
    switch ( alignment_ )
    {
        case ( NoAlign ) : { break; }
        case ( LeftAlign ) : { break; }
        case ( RightAlign ) : { pad(n,ostream); break; }
        case ( CentreAlign ) : { pad(n/2+ n%2,ostream); break; } // Add the remainder
        default : break;
    }
}
template <typename OutputStream>
void Format<std::string>::postPad(int n, OutputStream &ostream) const
{
    if ( n <= 0 ) { return; }
    switch ( alignment_ )
    {
        case ( NoAlign ) : { break; }
        case ( LeftAlign ) : { pad(n,ostream); break; }
        case ( RightAlign ) : { break; }
        case ( CentreAlign ) : { pad(n/2,ostream); break; }  // Do not add the remainder
        default : break;
    }
}
template <typename OutputStream>
void Format<std::string>::pad(int n, OutputStream &ostream) const
{
    for (int i = n; i > 0; --i )
    {
        ostream << ' ';
    }
}

/*****************************************************************************
* Implementation [streaming]
*****************************************************************************/

template <typename OutputStream>
OutputStream& operator << (OutputStream &ostream, Format<std::string>& formatter )
{
    bool ready = formatter.ready_to_format;

    ecl_assert_throw(ready, StandardException(LOC,UsageError,"The formatter cannot print any data - "
            "either there is no data available, or you have tried to use the "
            "formatter more than once in a single streaming operation. "
            "C++ produces unspecified results when functors are used multiply "
            "in the same stream sequence, so this is not permitted here.") );

    if ( ready ) {
        formatter.format(ostream);
        formatter.ready_to_format = false;
    }

    return ostream;
}

} // namespace ecl

#endif /*ECL_FORMATTERS_STRINGS_HPP_*/