From 6efe0505dfeae91bc3fada3b416fbc474a33d299 Mon Sep 17 00:00:00 2001
From: Isaac <isaacOscar@hotmail.com>
Date: Tue, 9 Apr 2019 13:48:46 +1200
Subject: [PATCH] Make math autocorrrect work with more than 2 chars

Currently, math autocorrect allows to transform a couple of characters
to a new one. This patch allows to transform a couple (sequence,
character) to a new character.

No example are implemented right now. One possible idea would be
"--" + ">" => \longrightarrow
---
 src/mathed/InsetMathNest.cpp   |  2 +-
 src/mathed/MathAutoCorrect.cpp | 44 ++++++++++++++++++++--------------
 src/mathed/MathAutoCorrect.h   |  4 ++--
 3 files changed, 29 insertions(+), 21 deletions(-)

diff --git a/src/mathed/InsetMathNest.cpp b/src/mathed/InsetMathNest.cpp
index 798ca8920b..85e4dd7c70 100644
--- a/src/mathed/InsetMathNest.cpp
+++ b/src/mathed/InsetMathNest.cpp
@@ -1868,7 +1868,7 @@ bool InsetMathNest::interpretChar(Cursor & cur, char_type const c)
 
 	// try auto-correction
 	if (lyxrc.autocorrection_math && cur.autocorrect() && cur.pos() != 0
-		  && math_autocorrect(cur.prevAtom(), c))
+		  && math_autocorrect(cur, c))
 		return true;
 
 	// no special circumstances, so insert the character without any fuss
diff --git a/src/mathed/MathAutoCorrect.cpp b/src/mathed/MathAutoCorrect.cpp
index fc4ad440d2..be5aeb42d0 100644
--- a/src/mathed/MathAutoCorrect.cpp
+++ b/src/mathed/MathAutoCorrect.cpp
@@ -10,6 +10,7 @@
 
 #include <config.h>
 
+#include "Cursor.h"
 #include "MathAutoCorrect.h"
 #include "MathData.h"
 #include "InsetMath.h"
@@ -38,18 +39,18 @@ public:
 	/// \brief Correction
 	Correction() : from2_(0) {}
 	///
-	bool correct(MathAtom & at, char_type c) const;
+	bool correct(Cursor & cur, char_type c) const;
 	///
 	bool read(idocstream & is);
 	///
 	void write(odocstream & os) const;
 private:
 	///
-	MathAtom from1_;
+	MathData from1_;
 	///
 	char_type from2_;
 	///
-	MathAtom to_;
+	MathData to_;
 };
 
 
@@ -64,26 +65,35 @@ bool Correction::read(idocstream & is)
 	MathData ar1, ar3;
 	mathed_parse_cell(ar1, s1);
 	mathed_parse_cell(ar3, s3);
-	if (ar1.size() != 1 || ar3.size() != 1)
-		return false;
-	from1_ = ar1.front();
+	from1_ = ar1;
 	from2_ = s2[0];
-	to_    = ar3.front();
+	to_    = ar3;
 	return true;
 }
 
 
-bool Correction::correct(MathAtom & at, char_type c) const
+bool Correction::correct(Cursor & cur, char_type c) const
 {
 	//LYXERR(Debug::MATHED,
 	//	"trying to correct ar: " << at << " from: '" << from1_ << '\'');
 	if (from2_ != c)
 		return false;
-	if (asString(at) != asString(from1_))
+	pos_type n = from1_.size();
+	if (cur.pos() < pos_type(from1_.size())) // not enough to match
 		return false;
-	LYXERR(Debug::MATHED, "match found! subst in " << at
+	pos_type start = cur.pos() - from1_.size();
+
+	for (pos_type i = 0; i < n; i++)
+		if (asString(cur.cell()[start + i]) != asString(from1_[i]))
+			return false;
+
+	LYXERR(Debug::MATHED, "match found! subst in " << cur.cell()
 		<< " from: '" << from1_ << "' to '" << to_ << '\'');
-	at = to_;
+
+	cur.cell().erase(cur.pos() - n, cur.pos());
+	cur.pos() -= n;
+
+	cur.insert(to_);
 	return true;
 }
 
@@ -121,17 +131,17 @@ public:
 	///
 	void insert(const Correction & corr) { data_.push_back(corr); }
 	///
-	bool correct(MathAtom & at, char_type c) const;
+	bool correct(Cursor & cur, char_type c) const;
 private:
 	///
 	vector<Correction> data_;
 };
 
 
-bool Corrections::correct(MathAtom & at, char_type c) const
+bool Corrections::correct(Cursor & cur, char_type c) const
 {
 	for (const_iterator it = data_.begin(); it != data_.end(); ++it)
-		if (it->correct(at, c))
+		if (it->correct(cur, c))
 			return true;
 	return false;
 }
@@ -172,7 +182,7 @@ void initAutoCorrect()
 } // namespace
 
 
-bool math_autocorrect(MathAtom & at, char_type c)
+bool math_autocorrect(Cursor & cur, char_type c)
 {
 	static bool initialized = false;
 
@@ -181,8 +191,6 @@ bool math_autocorrect(MathAtom & at, char_type c)
 		initialized = true;
 	}
 
-	return theCorrections.correct(at, c);
+	return theCorrections.correct(cur, c);
 }
-
-
 } // namespace lyx
diff --git a/src/mathed/MathAutoCorrect.h b/src/mathed/MathAutoCorrect.h
index 679e83738e..a782d678ee 100644
--- a/src/mathed/MathAutoCorrect.h
+++ b/src/mathed/MathAutoCorrect.h
@@ -16,10 +16,10 @@
 
 namespace lyx {
 
-class MathAtom;
+class Cursor;
 
 // make "corrections" according to file lib/autocorrect
-bool math_autocorrect(MathAtom & at, char_type c);
+bool math_autocorrect(Cursor & cur, char_type c);
 
 } // namespace lyx
 
-- 
2.39.5