From 6c2430ce08d8fb1ce9b266a7be1607cc1fd432fe Mon Sep 17 00:00:00 2001
From: Maxime Coste <frrrwww@gmail.com>
Date: Sun, 31 Mar 2013 13:52:15 +0200
Subject: [PATCH] FlagLines updates the lines in the option according to buffer
 modifications

---
 src/highlighter.hh  |  2 +-
 src/highlighters.cc | 43 +++++++++++++++++++++++++++++++++++++------
 2 files changed, 38 insertions(+), 7 deletions(-)

diff --git a/src/highlighter.hh b/src/highlighter.hh
index 185a2b9d..274ce182 100644
--- a/src/highlighter.hh
+++ b/src/highlighter.hh
@@ -25,7 +25,7 @@ typedef std::pair<String, HighlighterFunc> HighlighterAndId;
 typedef memoryview<String> HighlighterParameters;
 
 using HighlighterFactory = std::function<HighlighterAndId (const HighlighterParameters& params,
-                                                           const Window& window)>;
+                                                           Window& window)>;
 
 using HighlighterGroup = FunctionGroup<DisplayBuffer&>;
 
diff --git a/src/highlighters.cc b/src/highlighters.cc
index 2aee8bd6..6b55cbb2 100644
--- a/src/highlighters.cc
+++ b/src/highlighters.cc
@@ -331,11 +331,12 @@ void expand_unprintable(DisplayBuffer& display_buffer)
     }
 }
 
-class FlagLines
+class FlagLines : public BufferChangeListener_AutoRegister
 {
 public:
-    FlagLines(Color bg, String option_name, const OptionManager& options)
-        : m_bg(bg), m_option_name(std::move(option_name)),
+    FlagLines(Color bg, String option_name, OptionManager& options, const Buffer& buffer)
+        : BufferChangeListener_AutoRegister(buffer),
+          m_bg(bg), m_option_name(std::move(option_name)),
           m_options(options)
     {
         // trigger an exception if option is not of right type.
@@ -360,18 +361,48 @@ public:
         }
     }
 
+    void on_insert(const BufferIterator& begin, const BufferIterator& end) override
+    {
+        LineCount new_lines = end.line() - begin.line();
+        if (new_lines == 0)
+            return;
+
+        auto lines = m_options[m_option_name].get<std::vector<LineAndFlag>>();
+        for (auto& line : lines)
+        {
+            if (std::get<0>(line) > begin.line())
+                std::get<0>(line) += new_lines;
+        }
+        m_options.get_local_option(m_option_name).set(lines);
+    }
+
+    void on_erase(const BufferIterator& begin, const BufferIterator& end)  override
+    {
+        LineCount removed_lines = end.line() - begin.line();
+        if (removed_lines == 0)
+            return;
+
+        auto lines = m_options[m_option_name].get<std::vector<LineAndFlag>>();
+        for (auto& line : lines)
+        {
+            if (std::get<0>(line) > begin.line())
+                std::get<0>(line) -= removed_lines;
+        }
+        m_options.get_local_option(m_option_name).set(lines);
+    }
+
 private:
     Color m_bg;
     String m_option_name;
-    const OptionManager& m_options;
+    OptionManager& m_options;
 };
 
-HighlighterAndId flag_lines_factory(const HighlighterParameters& params, const Window& window)
+HighlighterAndId flag_lines_factory(const HighlighterParameters& params, Window& window)
 {
     if (params.size() != 2)
         throw runtime_error("wrong parameter count");
 
-    return {"hlflags_" + params[1], FlagLines{str_to_color(params[0]), params[1], window.options()}};
+    return {"hlflags_" + params[1], FlagLines{str_to_color(params[0]), params[1], window.options(), window.buffer()}};
 }
 
 template<void (*highlighter_func)(DisplayBuffer&)>