From 02a2f97a593b0735af02532d206b34f9988c734d Mon Sep 17 00:00:00 2001
From: Carl Hetherington <cth@carlh.net>
Date: Mon, 15 Feb 2016 08:39:50 +0000
Subject: [PATCH] Basic support for parsing in-line markup in SSA.

---
 src/ssa_reader.cc       | 63 +++++++++++++++++++++++++++++++++++++++++
 src/ssa_reader.h        |  2 ++
 test/ssa_reader_test.cc | 38 +++++++++++++++++++++++++
 3 files changed, 103 insertions(+)

diff --git a/src/ssa_reader.cc b/src/ssa_reader.cc
index d4908a2..703ed26 100644
--- a/src/ssa_reader.cc
+++ b/src/ssa_reader.cc
@@ -34,6 +34,7 @@ using std::stringstream;
 using std::vector;
 using std::map;
 using std::cout;
+using std::list;
 using boost::optional;
 using boost::function;
 using namespace boost::algorithm;
@@ -137,6 +138,68 @@ SSAReader::parse_time (string t) const
 		);
 }
 
+list<RawSubtitle>
+SSAReader::parse_line (RawSubtitle base, string line)
+{
+	enum {
+		TEXT,
+		STYLE,
+		BACKSLASH
+	} state = TEXT;
+
+	list<RawSubtitle> subs;
+	RawSubtitle current = base;
+	string style;
+
+	current.vertical_position.line = 0;
+
+	for (size_t i = 0; i < line.length(); ++i) {
+		char const c = line[i];
+		switch (state) {
+		case TEXT:
+			if (c == '{') {
+				state = STYLE;
+			} else if (c == '\\') {
+				state = BACKSLASH;
+			} else {
+				current.text += c;
+			}
+			break;
+		case STYLE:
+			if (c == '}') {
+				if (!current.text.empty ()) {
+					subs.push_back (current);
+					current.text = "";
+				}
+				if (style == "i1") {
+					current.italic = true;
+				} else if (style == "i0") {
+					current.italic = false;
+				}
+				style = "";
+				state = TEXT;
+			} else {
+				style += c;
+			}
+			break;
+		case BACKSLASH:
+			if (c == 'n' && !current.text.empty ()) {
+				subs.push_back (current);
+				current.text = "";
+				current.vertical_position.line = current.vertical_position.line.get() + 1;
+			}
+			state = TEXT;
+			break;
+		}
+	}
+
+	if (!current.text.empty ()) {
+		subs.push_back (current);
+	}
+
+	return subs;
+}
+
 void
 SSAReader::read (function<optional<string> ()> get_line)
 {
diff --git a/src/ssa_reader.h b/src/ssa_reader.h
index 0f575ff..1fe64f3 100644
--- a/src/ssa_reader.h
+++ b/src/ssa_reader.h
@@ -35,6 +35,8 @@ public:
 	SSAReader (FILE* f);
 	SSAReader (std::string const & subs);
 
+	static std::list<RawSubtitle> parse_line (RawSubtitle base, std::string line);
+
 private:
 	void read (boost::function<boost::optional<std::string> ()> get_line);
 	Time parse_time (std::string t) const;
diff --git a/test/ssa_reader_test.cc b/test/ssa_reader_test.cc
index c7594d7..97626a6 100644
--- a/test/ssa_reader_test.cc
+++ b/test/ssa_reader_test.cc
@@ -69,3 +69,41 @@ BOOST_AUTO_TEST_CASE (ssa_reader_test)
 
 	BOOST_CHECK (i == subs.end());
 }
+
+BOOST_AUTO_TEST_CASE (ssa_reader_line_test1)
+{
+	sub::RawSubtitle base;
+	list<sub::RawSubtitle> r = sub::SSAReader::parse_line (base, "This is a line with some {i1}italics{i0} and then\\nthere is a new line.");
+
+	list<sub::RawSubtitle>::const_iterator i = r.begin ();
+	BOOST_CHECK_EQUAL (i->text, "This is a line with some ");
+	BOOST_CHECK_EQUAL (i->italic, false);
+	++i;
+	BOOST_REQUIRE (i != r.end ());
+
+	BOOST_CHECK_EQUAL (i->text, "italics");
+	BOOST_CHECK_EQUAL (i->italic, true);
+	++i;
+	BOOST_REQUIRE (i != r.end ());
+
+	BOOST_CHECK_EQUAL (i->text, " and then");
+	BOOST_CHECK_EQUAL (i->italic, false);
+	++i;
+	BOOST_REQUIRE (i != r.end ());
+
+	BOOST_CHECK_EQUAL (i->text, "there is a new line.");
+	++i;
+	BOOST_REQUIRE (i == r.end ());
+}
+
+BOOST_AUTO_TEST_CASE (ssa_reader_line_test2)
+{
+	sub::RawSubtitle base;
+	list<sub::RawSubtitle> r = sub::SSAReader::parse_line (base, "{i1}It's all just italics{i0}");
+
+	list<sub::RawSubtitle>::const_iterator i = r.begin ();
+	BOOST_CHECK_EQUAL (i->text, "It's all just italics");
+	BOOST_CHECK_EQUAL (i->italic, true);
+	++i;
+	BOOST_REQUIRE (i == r.end ());
+}
-- 
2.30.2