[gnote] Only connect a single callback for format and make format static

[Aurimas Černius <aurimasc src gnome org>]

commit 6af9833ef6862e6eb930c8a3998f35453a3f0a69
Author: Aurimas Černius <aurisc4 gmail com>
Date:   Tue Jan 5 20:51:31 2021 +0200

    Only connect a single callback for format and make format static

 src/addins/inserttimestamp/inserttimestampnoteaddin.cpp | 14 ++++++++------
 src/addins/inserttimestamp/inserttimestampnoteaddin.hpp | 10 ++++++----
 2 files changed, 14 insertions(+), 10 deletions(-)
---
diff --git a/src/addins/inserttimestamp/inserttimestampnoteaddin.cpp 
b/src/addins/inserttimestamp/inserttimestampnoteaddin.cpp
index a7965169..5c7ef4ba 100644
--- a/src/addins/inserttimestamp/inserttimestampnoteaddin.cpp
+++ b/src/addins/inserttimestamp/inserttimestampnoteaddin.cpp
@@ -1,7 +1,7 @@
 /*
  * gnote
  *
- * Copyright (C) 2010-2013,2016-2017,2019-2020 Aurimas Cernius
+ * Copyright (C) 2010-2013,2016-2017,2019-2021 Aurimas Cernius
  * Copyright (C) 2009 Hubert Figuiere
  *
  * This program is free software: you can redistribute it and/or modify
@@ -55,9 +55,11 @@ namespace inserttimestamp {
     register_main_window_action_callback("inserttimestamp-insert",
       sigc::mem_fun(*this, &InsertTimestampNoteAddin::on_menu_item_activated));
 
-    InsertTimestampPreferences::settings()->signal_changed(INSERT_TIMESTAMP_FORMAT).connect(
-      sigc::mem_fun(*this, &InsertTimestampNoteAddin::on_format_setting_changed));
-    m_date_format = InsertTimestampPreferences::settings()->get_string(INSERT_TIMESTAMP_FORMAT);
+    if(s_on_format_setting_changed_cid.empty()) {
+      s_on_format_setting_changed_cid = 
InsertTimestampPreferences::settings()->signal_changed(INSERT_TIMESTAMP_FORMAT)
+        .connect(sigc::ptr_fun(InsertTimestampNoteAddin::on_format_setting_changed));
+      s_date_format = InsertTimestampPreferences::settings()->get_string(INSERT_TIMESTAMP_FORMAT);
+    }
   }
 
 
@@ -72,7 +74,7 @@ namespace inserttimestamp {
 
   void InsertTimestampNoteAddin::on_menu_item_activated(const Glib::VariantBase&)
   {
-    Glib::ustring text = sharp::date_time_to_string(Glib::DateTime::create_now_local(), m_date_format);
+    Glib::ustring text = sharp::date_time_to_string(Glib::DateTime::create_now_local(), s_date_format);
     Gtk::TextIter cursor = get_buffer()->get_iter_at_mark (get_buffer()->get_insert());
     std::vector<Glib::ustring> names;
     names.push_back("datetime");
@@ -82,7 +84,7 @@ namespace inserttimestamp {
 
   void InsertTimestampNoteAddin::on_format_setting_changed(const Glib::ustring &)
   {
-    m_date_format = InsertTimestampPreferences::settings()->get_string(INSERT_TIMESTAMP_FORMAT);
+    s_date_format = InsertTimestampPreferences::settings()->get_string(INSERT_TIMESTAMP_FORMAT);
   }
 
 }
diff --git a/src/addins/inserttimestamp/inserttimestampnoteaddin.hpp 
b/src/addins/inserttimestamp/inserttimestampnoteaddin.hpp
index a8891182..26814182 100644
--- a/src/addins/inserttimestamp/inserttimestampnoteaddin.hpp
+++ b/src/addins/inserttimestamp/inserttimestampnoteaddin.hpp
@@ -1,7 +1,7 @@
 /*
  * gnote
  *
- * Copyright (C) 2010,2013,2016-2017,2019 Aurimas Cernius
+ * Copyright (C) 2010,2013,2016-2017,2019,2021 Aurimas Cernius
  * Copyright (C) 2009 Hubert Figuiere
  *
  * This program is free software: you can redistribute it and/or modify
@@ -54,10 +54,12 @@ public:
   virtual void on_note_opened() override;
   virtual std::vector<gnote::PopoverWidget> get_actions_popover_widgets() const override;
 private:
-  void on_menu_item_activated(const Glib::VariantBase&);
-  void on_format_setting_changed(const Glib::ustring & key);
+  static void on_format_setting_changed(const Glib::ustring & key);
+
+  static Glib::ustring s_date_format;
+  static sigc::connection s_on_format_setting_changed_cid;
 
-  Glib::ustring    m_date_format;
+  void on_menu_item_activated(const Glib::VariantBase&);
 };
 
 }