Chris@16: //  Copyright (c) 2001-2011 Hartmut Kaiser
Chris@16: //
Chris@16: //  Distributed under the Boost Software License, Version 1.0. (See accompanying
Chris@16: //  file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
Chris@16: 
Chris@16: #if !defined(BOOST_SPIRIT_KARMA_CENTER_ALIGNMENT_FEB_27_2007_1216PM)
Chris@16: #define BOOST_SPIRIT_KARMA_CENTER_ALIGNMENT_FEB_27_2007_1216PM
Chris@16: 
Chris@16: #if defined(_MSC_VER)
Chris@16: #pragma once
Chris@16: #endif
Chris@16: 
Chris@16: #include <boost/spirit/home/karma/meta_compiler.hpp>
Chris@16: #include <boost/spirit/home/karma/generator.hpp>
Chris@16: #include <boost/spirit/home/karma/domain.hpp>
Chris@16: #include <boost/spirit/home/karma/detail/output_iterator.hpp>
Chris@16: #include <boost/spirit/home/karma/detail/default_width.hpp>
Chris@16: #include <boost/spirit/home/karma/delimit_out.hpp>
Chris@16: #include <boost/spirit/home/karma/auxiliary/lazy.hpp>
Chris@16: #include <boost/spirit/home/support/unused.hpp>
Chris@16: #include <boost/spirit/home/support/common_terminals.hpp>
Chris@16: #include <boost/spirit/home/support/has_semantic_action.hpp>
Chris@16: #include <boost/spirit/home/support/handles_container.hpp>
Chris@16: #include <boost/spirit/home/karma/detail/attributes.hpp>
Chris@16: #include <boost/spirit/home/support/info.hpp>
Chris@16: #include <boost/spirit/home/support/unused.hpp>
Chris@16: #include <boost/fusion/include/at.hpp>
Chris@16: #include <boost/fusion/include/vector.hpp>
Chris@16: #include <boost/lexical_cast.hpp>
Chris@16: #include <boost/integer_traits.hpp>
Chris@16: #include <boost/mpl/bool.hpp>
Chris@16: #include <boost/utility/enable_if.hpp>
Chris@16: #include <boost/detail/workaround.hpp>
Chris@16: 
Chris@16: ///////////////////////////////////////////////////////////////////////////////
Chris@16: namespace boost { namespace spirit
Chris@16: {
Chris@16:     ///////////////////////////////////////////////////////////////////////////
Chris@16:     // Enablers
Chris@16:     ///////////////////////////////////////////////////////////////////////////
Chris@16: 
Chris@16:     // enables center[]
Chris@16:     template <>
Chris@16:     struct use_directive<karma::domain, tag::center>
Chris@16:       : mpl::true_ {};
Chris@16: 
Chris@16:     // enables center(d)[g] and center(w)[g], where d is a generator
Chris@16:     // and w is a maximum width
Chris@16:     template <typename T>
Chris@16:     struct use_directive<karma::domain
Chris@16:           , terminal_ex<tag::center, fusion::vector1<T> > >
Chris@16:       : mpl::true_ {};
Chris@16: 
Chris@16:     // enables *lazy* center(d)[g], where d provides a generator
Chris@16:     template <>
Chris@16:     struct use_lazy_directive<karma::domain, tag::center, 1>
Chris@16:       : mpl::true_ {};
Chris@16: 
Chris@16:     // enables center(w, d)[g], where d is a generator and w is a maximum
Chris@16:     // width
Chris@16:     template <typename Width, typename Padding>
Chris@16:     struct use_directive<karma::domain
Chris@16:           , terminal_ex<tag::center, fusion::vector2<Width, Padding> > >
Chris@16:       : spirit::traits::matches<karma::domain, Padding> {};
Chris@16: 
Chris@16:     // enables *lazy* center(w, d)[g], where d provides a generator and w is
Chris@16:     // a maximum width
Chris@16:     template <>
Chris@16:     struct use_lazy_directive<karma::domain, tag::center, 2>
Chris@16:       : mpl::true_ {};
Chris@16: 
Chris@16: }}
Chris@16: 
Chris@16: ///////////////////////////////////////////////////////////////////////////////
Chris@16: namespace boost { namespace spirit { namespace karma
Chris@16: {
Chris@16: #ifndef BOOST_SPIRIT_NO_PREDEFINED_TERMINALS
Chris@16:     using spirit::center;
Chris@16: #endif
Chris@16:     using spirit::center_type;
Chris@16: 
Chris@16:     namespace detail
Chris@16:     {
Chris@16:         ///////////////////////////////////////////////////////////////////////
Chris@16:         //  The center_generate template function is used for all the
Chris@16:         //  different flavors of the center[] directive.
Chris@16:         ///////////////////////////////////////////////////////////////////////
Chris@16:         template <typename OutputIterator, typename Context, typename Delimiter,
Chris@16:             typename Attribute, typename Embedded, typename Padding>
Chris@16:         inline static bool
Chris@16:         center_generate(OutputIterator& sink, Context& ctx,
Chris@16:             Delimiter const& d, Attribute const& attr, Embedded const& e,
Chris@16:             unsigned int const width, Padding const& p)
Chris@16:         {
Chris@16: #if BOOST_WORKAROUND(BOOST_MSVC, BOOST_TESTED_AT(1600))
Chris@16:             e; // suppresses warning: C4100: 'e' : unreferenced formal parameter
Chris@16: #endif
Chris@16:             // wrap the given output iterator to allow left padding
Chris@16:             detail::enable_buffering<OutputIterator> buffering(sink, width);
Chris@16:             bool r = false;
Chris@16: 
Chris@16:             // first generate the embedded output
Chris@16:             {
Chris@16:                 detail::disable_counting<OutputIterator> nocounting(sink);
Chris@16:                 r = e.generate(sink, ctx, d, attr);
Chris@16:             }   // re-enable counting
Chris@16: 
Chris@16:             buffering.disable();    // do not perform buffering any more
Chris@16: 
Chris@16:             // generate the left padding
Chris@16:             detail::enable_counting<OutputIterator> counting(sink);
Chris@16: 
Chris@16:             std::size_t const pre = width - (buffering.buffer_size() + width)/2;
Chris@16:             while (r && counting.count() < pre)
Chris@16:                 r = p.generate(sink, ctx, unused, unused);
Chris@16: 
Chris@16:             if (r) {
Chris@16:                 // copy the embedded output to the target output iterator
Chris@16:                 buffering.buffer_copy();
Chris@16: 
Chris@16:                 // generate the right padding
Chris@16:                 while (r && counting.count() < width)
Chris@16:                     r = p.generate(sink, ctx, unused, unused);
Chris@16:             }
Chris@16:             return r;
Chris@16:         }
Chris@16:     }
Chris@16: 
Chris@16:     ///////////////////////////////////////////////////////////////////////////
Chris@16:     //  The simple left alignment directive is used for center[...]
Chris@16:     //  generators. It uses default values for the generated width (defined via
Chris@16:     //  the BOOST_KARMA_DEFAULT_FIELD_LENGTH constant) and for the padding
Chris@16:     //  generator (always spaces).
Chris@16:     ///////////////////////////////////////////////////////////////////////////
Chris@16:     template <typename Subject, typename Width = detail::default_width>
Chris@16:     struct simple_center_alignment
Chris@16:       : unary_generator<simple_center_alignment<Subject, Width> >
Chris@16:     {
Chris@16:         typedef Subject subject_type;
Chris@16: 
Chris@16:         typedef mpl::int_<
Chris@16:             generator_properties::countingbuffer | subject_type::properties::value
Chris@16:         > properties;
Chris@16: 
Chris@16:         template <typename Context, typename Iterator>
Chris@16:         struct attribute
Chris@16:           : traits::attribute_of<subject_type, Context, Iterator>
Chris@16:         {};
Chris@16: 
Chris@16:         simple_center_alignment(Subject const& subject, Width width = Width())
Chris@16:           : subject(subject), width(width) {}
Chris@16: 
Chris@16:         template <typename OutputIterator, typename Context, typename Delimiter
Chris@16:           , typename Attribute>
Chris@16:         bool generate(OutputIterator& sink, Context& ctx, Delimiter const& d
Chris@16:           , Attribute const& attr) const
Chris@16:         {
Chris@16:             return detail::center_generate(sink, ctx, d, attr,
Chris@16:                 subject, width, compile<karma::domain>(' '));
Chris@16:         }
Chris@16: 
Chris@16:         template <typename Context>
Chris@16:         info what(Context& context) const
Chris@16:         {
Chris@16:             return info("center", subject.what(context));
Chris@16:         }
Chris@16: 
Chris@16:         Subject subject;
Chris@16:         Width width;
Chris@16:     };
Chris@16: 
Chris@16:     ///////////////////////////////////////////////////////////////////////////
Chris@16:     //  The left alignment directive with padding, is used for generators like
Chris@16:     //  center(padding)[...], where padding is a arbitrary generator
Chris@16:     //  expression. It uses a default value for the generated width (defined
Chris@16:     //  via the BOOST_KARMA_DEFAULT_FIELD_LENGTH constant).
Chris@16:     ///////////////////////////////////////////////////////////////////////////
Chris@16:     template <typename Subject, typename Padding
Chris@16:       , typename Width = detail::default_width>
Chris@16:     struct padding_center_alignment
Chris@16:       : unary_generator<padding_center_alignment<Subject, Padding, Width> >
Chris@16:     {
Chris@16:         typedef Subject subject_type;
Chris@16:         typedef Padding padding_type;
Chris@16: 
Chris@16:         typedef mpl::int_<
Chris@16:             generator_properties::countingbuffer |
Chris@16:             subject_type::properties::value | padding_type::properties::value
Chris@16:         > properties;
Chris@16: 
Chris@16:         template <typename Context, typename Iterator>
Chris@16:         struct attribute
Chris@16:           : traits::attribute_of<Subject, Context, Iterator>
Chris@16:         {};
Chris@16: 
Chris@16:         padding_center_alignment(Subject const& subject, Padding const& padding
Chris@16:               , Width width = Width())
Chris@16:           : subject(subject), padding(padding), width(width) {}
Chris@16: 
Chris@16:         template <typename OutputIterator, typename Context, typename Delimiter
Chris@16:           , typename Attribute>
Chris@16:         bool generate(OutputIterator& sink, Context& ctx, Delimiter const& d
Chris@16:           , Attribute const& attr) const
Chris@16:         {
Chris@16:             return detail::center_generate(sink, ctx, d, attr,
Chris@16:                 subject, width, padding);
Chris@16:         }
Chris@16: 
Chris@16:         template <typename Context>
Chris@16:         info what(Context& context) const
Chris@16:         {
Chris@16:             return info("center", subject.what(context));
Chris@16:         }
Chris@16: 
Chris@16:         Subject subject;
Chris@16:         Padding padding;
Chris@16:         Width width;
Chris@16:     };
Chris@16: 
Chris@16:     ///////////////////////////////////////////////////////////////////////////
Chris@16:     // Generator generators: make_xxx function (objects)
Chris@16:     ///////////////////////////////////////////////////////////////////////////
Chris@16: 
Chris@16:     // creates center[] directive generator
Chris@16:     template <typename Subject, typename Modifiers>
Chris@16:     struct make_directive<tag::center, Subject, Modifiers>
Chris@16:     {
Chris@16:         typedef simple_center_alignment<Subject> result_type;
Chris@16:         result_type operator()(unused_type, Subject const& subject
Chris@16:           , unused_type) const
Chris@16:         {
Chris@16:             return result_type(subject);
Chris@16:         }
Chris@16:     };
Chris@16: 
Chris@16:     // creates center(width)[] directive generator
Chris@16:     template <typename Width, typename Subject, typename Modifiers>
Chris@16:     struct make_directive<
Chris@16:         terminal_ex<tag::center, fusion::vector1<Width> >
Chris@16:       , Subject, Modifiers
Chris@16:       , typename enable_if_c< integer_traits<Width>::is_integral >::type>
Chris@16:     {
Chris@16:         typedef simple_center_alignment<Subject, Width> result_type;
Chris@16: 
Chris@16:         template <typename Terminal>
Chris@16:         result_type operator()(Terminal const& term, Subject const& subject
Chris@16:           , unused_type) const
Chris@16:         {
Chris@16:             return result_type(subject, fusion::at_c<0>(term.args));
Chris@16:         }
Chris@16:     };
Chris@16: 
Chris@16:     // creates center(pad)[] directive generator
Chris@16:     template <typename Padding, typename Subject, typename Modifiers>
Chris@16:     struct make_directive<
Chris@16:         terminal_ex<tag::center, fusion::vector1<Padding> >
Chris@16:       , Subject, Modifiers
Chris@16:       , typename enable_if<
Chris@16:             mpl::and_<
Chris@16:                 spirit::traits::matches<karma::domain, Padding>,
Chris@16:                 mpl::not_<mpl::bool_<integer_traits<Padding>::is_integral> >
Chris@16:             >
Chris@16:         >::type>
Chris@16:     {
Chris@16:         typedef typename
Chris@16:             result_of::compile<karma::domain, Padding, Modifiers>::type
Chris@16:         padding_type;
Chris@16: 
Chris@16:         typedef padding_center_alignment<Subject, padding_type> result_type;
Chris@16: 
Chris@16:         template <typename Terminal>
Chris@16:         result_type operator()(Terminal const& term, Subject const& subject
Chris@16:           , Modifiers const& modifiers) const
Chris@16:         {
Chris@16:             return result_type(subject
Chris@16:               , compile<karma::domain>(fusion::at_c<0>(term.args), modifiers));
Chris@16:         }
Chris@16:     };
Chris@16: 
Chris@16:     // creates center(width, pad)[] directive generator
Chris@16:     template <typename Width, typename Padding, typename Subject
Chris@16:       , typename Modifiers>
Chris@16:     struct make_directive<
Chris@16:         terminal_ex<tag::center, fusion::vector2<Width, Padding> >
Chris@16:       , Subject, Modifiers>
Chris@16:     {
Chris@16:         typedef typename
Chris@16:             result_of::compile<karma::domain, Padding, Modifiers>::type
Chris@16:         padding_type;
Chris@16: 
Chris@16:         typedef padding_center_alignment<Subject, padding_type, Width> result_type;
Chris@16: 
Chris@16:         template <typename Terminal>
Chris@16:         result_type operator()(Terminal const& term, Subject const& subject
Chris@16:           , Modifiers const& modifiers) const
Chris@16:         {
Chris@16:             return result_type(subject
Chris@16:               , compile<karma::domain>(fusion::at_c<1>(term.args), modifiers)
Chris@16:               , fusion::at_c<0>(term.args));
Chris@16:         }
Chris@16:     };
Chris@16: 
Chris@16: }}} // namespace boost::spirit::karma
Chris@16: 
Chris@16: namespace boost { namespace spirit { namespace traits
Chris@16: {
Chris@16:     ///////////////////////////////////////////////////////////////////////////
Chris@16:     template <typename Subject, typename Width>
Chris@16:     struct has_semantic_action<karma::simple_center_alignment<Subject, Width> >
Chris@16:       : unary_has_semantic_action<Subject> {};
Chris@16: 
Chris@16:     template <typename Subject, typename Padding, typename Width>
Chris@16:     struct has_semantic_action<
Chris@16:             karma::padding_center_alignment<Subject, Padding, Width> >
Chris@16:       : unary_has_semantic_action<Subject> {};
Chris@16: 
Chris@16:     ///////////////////////////////////////////////////////////////////////////
Chris@16:     template <typename Subject, typename Width, typename Attribute
Chris@16:       , typename Context, typename Iterator>
Chris@16:     struct handles_container<
Chris@16:             karma::simple_center_alignment<Subject, Width>, Attribute
Chris@16:           , Context, Iterator>
Chris@16:       : unary_handles_container<Subject, Attribute, Context, Iterator> {};
Chris@16: 
Chris@16:     template <typename Subject, typename Padding, typename Width
Chris@16:       , typename Attribute, typename Context, typename Iterator>
Chris@16:     struct handles_container<
Chris@16:             karma::padding_center_alignment<Subject, Padding, Width>
Chris@16:           , Attribute, Context, Iterator>
Chris@16:       : unary_handles_container<Subject, Attribute, Context, Iterator> {};
Chris@16: }}}
Chris@16: 
Chris@16: #endif
Chris@16: 
Chris@16: