Salastil/ncmpcpp
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

format: add ability to extract tags from a song

Browse Source
This commit is contained in:
Andrzej Rybczak
2016-01-16 16:31:27 +01:00
parent 9890a100df
commit b48dd14102
2 changed files with 44 additions and 7 deletions
Download Patch File Download Diff File Expand all files Collapse all files

4
src/format.h
View File

@@ -60,6 +60,10 @@ private:
unsigned m_delimiter;
};
template <typename CharT> using SongTagMap = std::vector<
std::pair<SongTag, std::basic_string<CharT> >
>;
enum class Result { Empty, Missing, Ok };
template <typename CharT>

47
src/format_impl.h
View File

@@ -130,7 +130,7 @@ struct Printer: boost::static_visitor<Result>
else
tags = wideShorten(tags, st.delimiter());
}
output(tags);
output(tags, &st);
return Result::Ok;
}
else
@@ -177,10 +177,11 @@ private:
// generic version for streams (buffers, menus)
template <typename ValueT, typename OutputStreamT>
struct output_ {
static void exec(OutputStreamT &os, const ValueT &value) {
static void exec(OutputStreamT &os, const ValueT &value, const SongTag *) {
os << value;
}
};
// specialization for strings (input/output)
template <typename SomeCharT, typename OtherCharT>
struct output_<std::basic_string<SomeCharT>, std::basic_string<OtherCharT>> {
@@ -191,7 +192,7 @@ private:
static typename std::enable_if<
std::is_same<SomeString, OtherString>::value,
void
>::type exec(SomeString &result, const OtherString &s) {
>::type exec(SomeString &result, const OtherString &s, const SongTag *) {
result += s;
}
};
@@ -199,20 +200,43 @@ private:
// properties. if this code is reached, throw an exception.
template <typename ValueT, typename SomeCharT>
struct output_<ValueT, std::basic_string<SomeCharT>> {
static void exec(std::basic_string<CharT> &, const ValueT &) {
static void exec(std::basic_string<CharT> &, const ValueT &, const SongTag *) {
throw std::logic_error("non-string property can't be appended to the string");
}
};
// Specialization for SongTagMap.
template <typename SomeCharT, typename OtherCharT>
struct output_<std::basic_string<SomeCharT>, SongTagMap<OtherCharT> > {
// Compile only if string types are the same.
static typename std::enable_if<
std::is_same<SomeCharT, OtherCharT>::value,
void
>::type exec(SongTagMap<OtherCharT> &acc,
const std::basic_string<SomeCharT> &s, const SongTag *st) {
if (st != nullptr) {
acc.emplace_back(*st, s);
}
}
};
// When extracting tags from a song all the other properties should
// be ignored. If that's not the case, throw an exception.
template <typename ValueT, typename SomeCharT>
struct output_<ValueT, SongTagMap<SomeCharT> > {
static void exec(SongTagMap<SomeCharT> &, const ValueT &, const SongTag *) {
throw std::logic_error("Non-string property can't be inserted into the SongTagMap");
}
};
template <typename ValueT>
void output(const ValueT &value) const
void output(const ValueT &value, const SongTag *st = nullptr) const
{
if (!m_no_output)
{
if (m_output_switched && m_second_os != nullptr)
output_<ValueT, SecondOutputT>::exec(*m_second_os, value);
output_<ValueT, SecondOutputT>::exec(*m_second_os, value, st);
else
output_<ValueT, OutputT>::exec(m_output, value);
output_<ValueT, OutputT>::exec(m_output, value, st);
}
}
@@ -258,6 +282,15 @@ std::basic_string<CharT> stringify(const AST<CharT> &ast, const MPD::Song *song)
return result;
}
template <typename CharT>
SongTagMap<CharT> extractTags(const AST<CharT> &ast, const MPD::Song &song)
{
SongTagMap<CharT> result;
Printer<CharT, SongTagMap<CharT> > printer(result, &song, &result, Flags::Tag);
visit(printer, ast);
return result;
}
}
#endif // NCMPCPP_HAVE_FORMAT__IMPL_H