[gtkmm-documentation] Fix 'make check' with the latest gtkmm version

[Kjell Ahlstedt <kjellahl src gnome org>]

commit 070d462beea3ef5278cdd3b19e16bd8545483444
Author: Kjell Ahlstedt <kjell ahlstedt bredband net>
Date:   Mon Mar 24 12:32:48 2014 +0100

    Fix 'make check' with the latest gtkmm version
    
    * examples/book/scrolledwindow/examplewindow.[cc|h]:
    Use Gtk::Dialog::add_button() instead of the deprecated get_action_area().

 examples/book/scrolledwindow/examplewindow.cc |   34 ++++++++++++------------
 examples/book/scrolledwindow/examplewindow.h  |    3 +-
 2 files changed, 18 insertions(+), 19 deletions(-)
---
diff --git a/examples/book/scrolledwindow/examplewindow.cc b/examples/book/scrolledwindow/examplewindow.cc
index 76334ad..3f68fe3 100644
--- a/examples/book/scrolledwindow/examplewindow.cc
+++ b/examples/book/scrolledwindow/examplewindow.cc
@@ -17,10 +17,9 @@
  */
 
 #include "examplewindow.h"
-#include <cstdio>
+#include <iostream>
 
 ExampleWindow::ExampleWindow()
-: m_Button_Close("Close")
 {
   set_title("Gtk::ScrolledWindow example");
   set_border_width(0);
@@ -58,19 +57,12 @@ ExampleWindow::ExampleWindow()
   }
 
   /* Add a "close" button to the bottom of the dialog */
-  m_Button_Close.signal_clicked().connect( sigc::mem_fun(*this,
-              &ExampleWindow::on_button_close));
+  add_button("_Close", Gtk::RESPONSE_CLOSE);
+  signal_response().connect(sigc::mem_fun(*this, &ExampleWindow::on_dialog_response));
 
-  /* this makes it so the button is the default. */
-  m_Button_Close.set_can_default();
-
-  Gtk::Box* pBox = get_action_area();
-  if(pBox)
-    pBox->pack_start(m_Button_Close);
-
-  /* This grabs this button to be the default button. Simply hitting
-   * the "Enter" key will cause this button to activate. */
-  m_Button_Close.grab_default();
+  /* This makes it so the button is the default.
+   * Simply hitting the "Enter" key will cause this button to activate. */
+  set_default_response(Gtk::RESPONSE_CLOSE);
 
   show_all_children();
 }
@@ -79,8 +71,16 @@ ExampleWindow::~ExampleWindow()
 {
 }
 
-void ExampleWindow::on_button_close()
+void ExampleWindow::on_dialog_response(int response_id)
 {
-  hide();
+  switch (response_id)
+  {
+  case Gtk::RESPONSE_CLOSE:
+  case Gtk::RESPONSE_DELETE_EVENT:
+    hide();
+    break;
+  default:
+    std::cout << "Unexpected response_id=" << response_id << std::endl;
+    break;
+  }
 }
-
diff --git a/examples/book/scrolledwindow/examplewindow.h b/examples/book/scrolledwindow/examplewindow.h
index 3e0e7e3..26b055b 100644
--- a/examples/book/scrolledwindow/examplewindow.h
+++ b/examples/book/scrolledwindow/examplewindow.h
@@ -29,12 +29,11 @@ public:
 
 protected:
   //Signal handlers:
-  void on_button_close();
+  void on_dialog_response(int response_id);
 
   //Child widgets:
   Gtk::ScrolledWindow m_ScrolledWindow;
   Gtk::Grid m_Grid;
-  Gtk::Button m_Button_Close;
 };
 
 #endif //GTKMM_EXAMPLEWINDOW_H