[gtkmm-documentation] Update the others/cellrenderercustom example

[Kjell Ahlstedt <kjellahl src gnome org>]

commit 7764cbc2a6ae461357eaa1009aa05f8c30695654
Author: Kjell Ahlstedt <kjell ahlstedt bredband net>
Date:   Mon Jan 9 09:00:08 2017 +0100

    Update the others/cellrenderercustom example
    
    Don't assume that Gtk::Style exists. It's no longer declared in widget.h.
    Use signal_style_updated() instead of signal_style_changed().

 .../others/cellrenderercustom/cellrendererpopup.cc |    4 ++--
 .../others/cellrenderercustom/cellrendererpopup.h  |    2 +-
 .../cellrenderercustom/cellrenderertoggle.cc       |    2 +-
 3 files changed, 4 insertions(+), 4 deletions(-)
---
diff --git a/examples/others/cellrenderercustom/cellrendererpopup.cc 
b/examples/others/cellrenderercustom/cellrendererpopup.cc
index 84a7bae..606c7c9 100644
--- a/examples/others/cellrenderercustom/cellrendererpopup.cc
+++ b/examples/others/cellrenderercustom/cellrendererpopup.cc
@@ -57,7 +57,7 @@ CellRendererPopup::CellRendererPopup()
 
   popup_window_.signal_button_press_event().connect(sigc::mem_fun(*this, &Self::on_button_press_event));
   popup_window_.signal_key_press_event   ().connect(sigc::mem_fun(*this, &Self::on_key_press_event));
-  //TODO: popup_window_.signal_style_changed     ().connect(sigc::mem_fun(*this, &Self::on_style_changed));
+  popup_window_.signal_style_updated     ().connect(sigc::mem_fun(*this, &Self::on_style_updated));
 }
 
 CellRendererPopup::~CellRendererPopup()
@@ -269,7 +269,7 @@ bool CellRendererPopup::on_key_press_event(GdkEventKey* event)
   return true;
 }
 
-void CellRendererPopup::on_style_changed(const Glib::RefPtr<Gtk::Style>&)
+void CellRendererPopup::on_style_updated()
 {
   // Invalidate the cache.
   button_width_ = -1;
diff --git a/examples/others/cellrenderercustom/cellrendererpopup.h 
b/examples/others/cellrenderercustom/cellrendererpopup.h
index 35f2db9..9d15c36 100644
--- a/examples/others/cellrenderercustom/cellrendererpopup.h
+++ b/examples/others/cellrenderercustom/cellrendererpopup.h
@@ -76,7 +76,7 @@ private:
 
   bool on_button_press_event(GdkEventButton* event);
   bool on_key_press_event(GdkEventKey* event);
-  void on_style_changed(const Glib::RefPtr<Gtk::Style>& previous_style);
+  void on_style_updated();
 
   void on_popup_editing_done();
   void on_popup_arrow_clicked();
diff --git a/examples/others/cellrenderercustom/cellrenderertoggle.cc 
b/examples/others/cellrenderercustom/cellrenderertoggle.cc
index 9e78f73..1810d2b 100644
--- a/examples/others/cellrenderercustom/cellrenderertoggle.cc
+++ b/examples/others/cellrenderercustom/cellrenderertoggle.cc
@@ -52,7 +52,7 @@ protected:
                             Gtk::Widget& widget,
                             const Gdk::Rectangle& background_area,
                             const Gdk::Rectangle& cell_area,
-                            Gtk::CellRendererState flag) override;
+                            Gtk::CellRendererState flag) /* override */;
 
   bool activate_vfunc(GdkEvent* event,
                               Gtk::Widget& widget,