[gnote] Add accelerators for switching tabs in main window

[Aurimas Černius <aurimasc src gnome org>]

commit 3f1c4b1c82a4bf65636986a712a5a2f13efc1a3d
Author: Aurimas Černius <aurisc4 gmail com>
Date:   Sun May 8 21:17:10 2022 +0300

    Add accelerators for switching tabs in main window
    
    Fixes https://gitlab.gnome.org/GNOME/gnote/-/issues/124

 src/recentchanges.cpp | 23 +++++++++++++++++++++++
 src/recentchanges.hpp |  2 ++
 2 files changed, 25 insertions(+)
---
diff --git a/src/recentchanges.cpp b/src/recentchanges.cpp
index 35875c9f..ac7264cb 100644
--- a/src/recentchanges.cpp
+++ b/src/recentchanges.cpp
@@ -154,6 +154,10 @@ namespace gnote {
                                 GDK_KEY_W, Gdk::CONTROL_MASK, (Gtk::AccelFlags)0);
     m_keybinder.add_accelerator(sigc::mem_fun(*this, &NoteRecentChanges::close_window),
                                 GDK_KEY_Q, Gdk::CONTROL_MASK, (Gtk::AccelFlags)0);
+    m_keybinder.add_accelerator(sigc::mem_fun(*this, &NoteRecentChanges::next_tab),
+                                GDK_KEY_Page_Down, Gdk::CONTROL_MASK, (Gtk::AccelFlags)0);
+    m_keybinder.add_accelerator(sigc::mem_fun(*this, &NoteRecentChanges::previous_tab),
+                                GDK_KEY_Page_Up, Gdk::CONTROL_MASK, (Gtk::AccelFlags)0);
   }
 
 
@@ -610,6 +614,25 @@ namespace gnote {
     return true;
   }
 
+  void NoteRecentChanges::next_tab()
+  {
+    int next_page = 1 + m_embed_book.get_current_page();
+    if(next_page >= m_embed_book.get_n_pages()) {
+      next_page = 0;
+    }
+
+    m_embed_book.set_current_page(next_page);
+  }
+
+  void NoteRecentChanges::previous_tab()
+  {
+    int prev_page = m_embed_book.get_current_page() - 1;
+    if(prev_page < 0) {
+      prev_page = m_embed_book.get_n_pages() - 1;
+    }
+
+    m_embed_book.set_current_page(prev_page);
+  }
 
   void NoteRecentChanges::on_show()
   {
diff --git a/src/recentchanges.hpp b/src/recentchanges.hpp
index edbdcf36..48f53272 100644
--- a/src/recentchanges.hpp
+++ b/src/recentchanges.hpp
@@ -105,6 +105,8 @@ private:
   void callbacks_changed();
   void register_callbacks();
   void unregister_callbacks();
+  void next_tab();
+  void previous_tab();
 
   IGnote             &m_gnote;
   NoteManagerBase    &m_note_manager;