Shown below is a simple example of how to use the FileDialog class in a program. This simple program has a menubar with a File Dialog menu item. When you select this menu item, a dialog pops up showing a list of files. If you select Recent in the sidebar, the list of recently used files is shown.

After selecting the File Dialog menu item and the Recent sidebar item, you should see something similar to the following window.

Source Code

File: examplewindow.h (For use with gtkmm 4)

#ifndef GTKMM_EXAMPLEWINDOW_H
#define GTKMM_EXAMPLEWINDOW_H

#include <gtkmm.h>

class ExampleWindow : public Gtk::Window
{
public:
  ExampleWindow(const Glib::RefPtr<Gtk::Application>& app);
  ~ExampleWindow() override;

protected:
  //Signal handlers:
  void on_menu_file_files_dialog();
  void on_menu_file_quit();
  void on_menu_file_new();
  void on_dialog_finish(Glib::RefPtr<Gio::AsyncResult>& result);

  //Child widgets:
  Gtk::Box m_Box;

  Glib::RefPtr<Gtk::Builder> m_refBuilder;
  Glib::RefPtr<Gio::SimpleActionGroup> m_refActionGroup;

  Glib::RefPtr<Gtk::RecentManager> m_refRecentManager;
  Glib::RefPtr<Gtk::FileDialog> m_refFileDialog;
};

#endif //GTKMM_EXAMPLEWINDOW_H

File: examplewindow.cc (For use with gtkmm 4)

#include "examplewindow.h"
#include <iostream>

ExampleWindow::ExampleWindow(const Glib::RefPtr<Gtk::Application>& app)
: m_Box(Gtk::Orientation::VERTICAL),
  m_refRecentManager(Gtk::RecentManager::get_default())
{
  set_title("Recent files example");
  set_default_size(300, 150);

  //We can put a PopoverMenuBar at the top of the box and other stuff below it.
  set_child(m_Box);

  //Create actions for menus and toolbars:
  m_refActionGroup = Gio::SimpleActionGroup::create();

  //File menu:
  m_refActionGroup->add_action("new",
    sigc::mem_fun(*this, &ExampleWindow::on_menu_file_new));

  //A menu item to open the file dialog:
  m_refActionGroup->add_action("files-dialog",
    sigc::mem_fun(*this, &ExampleWindow::on_menu_file_files_dialog));

  m_refActionGroup->add_action("quit",
    sigc::mem_fun(*this, &ExampleWindow::on_menu_file_quit) );

  insert_action_group("example", m_refActionGroup);


  m_refBuilder = Gtk::Builder::create();

  // When the menubar is a child of a Gtk::Window, keyboard accelerators are not
  // automatically fetched from the Gio::Menu.
  // See the examples/book/menus/main_menu example for an alternative way of
  // adding the menubar when using Gtk::ApplicationWindow.
  app->set_accel_for_action("example.new", "<Primary>n");
  app->set_accel_for_action("example.files-dialog", "<Primary>o");
  app->set_accel_for_action("example.quit", "<Primary>q");

  //Layout the actions in a menubar and a toolbar:
  const char* ui_info =
    "<interface>"
    "  <menu id='menubar'>"
    "    <submenu>"
    "      <attribute name='label' translatable='yes'>_File</attribute>"
    "      <item>"
    "        <attribute name='label' translatable='yes'>_New</attribute>"
    "        <attribute name='action'>example.new</attribute>"
    "        <attribute name='accel'>&lt;Primary&gt;n</attribute>"
    "      </item>"
    "      <item>"
    "        <attribute name='label' translatable='yes'>File _Dialog</attribute>"
    "        <attribute name='action'>example.files-dialog</attribute>"
    "        <attribute name='accel'>&lt;Primary&gt;o</attribute>"
    "      </item>"
    "      <item>"
    "        <attribute name='label' translatable='yes'>_Quit</attribute>"
    "        <attribute name='action'>example.quit</attribute>"
    "        <attribute name='accel'>&lt;Primary&gt;q</attribute>"
    "      </item>"
    "    </submenu>"
    "  </menu>"
    "  <object class='GtkBox' id='toolbar'>"
    "    <property name='can_focus'>False</property>"
    "    <child>"
    "      <object class='GtkButton' id='toolbutton_new'>"
    "        <property name='can_focus'>False</property>"
    "        <property name='tooltip_text' translatable='yes'>New</property>"
    "        <property name='action_name'>example.new</property>"
    "        <property name='icon_name'>document-new</property>"
    "        <property name='hexpand'>False</property>"
    "        <property name='vexpand'>False</property>"
    "      </object>"
    "    </child>"
    "    <child>"
    "      <object class='GtkButton' id='toolbutton_quit'>"
    "        <property name='can_focus'>False</property>"
    "        <property name='tooltip_text' translatable='yes'>Quit</property>"
    "        <property name='action_name'>example.quit</property>"
    "        <property name='icon_name'>application-exit</property>"
    "        <property name='hexpand'>False</property>"
    "        <property name='vexpand'>False</property>"
    "      </object>"
    "    </child>"
    "  </object>"
    "</interface>";

  try
  {
    m_refBuilder->add_from_string(ui_info);
  }
  catch(const Glib::Error& ex)
  {
    std::cerr << "building menubar and toolbar failed: " <<  ex.what();
  }

  //Get the menubar and toolbar widgets, and add them to a container widget:
  auto object = m_refBuilder->get_object("menubar");
  auto gmenu = std::dynamic_pointer_cast<Gio::Menu>(object);
  if (gmenu)
  {
    //Menubar:
    auto pMenubar = Gtk::make_managed<Gtk::PopoverMenuBar>(gmenu);
    m_Box.append(*pMenubar);
  }
  else
    g_warning("GMenu not found");

  auto pToolbar = m_refBuilder->get_widget<Gtk::Box>("toolbar");
  if (pToolbar)
    //Toolbar:
    m_Box.append(*pToolbar);
  else
    g_warning("toolbar not found");
}

ExampleWindow::~ExampleWindow()
{
}

void ExampleWindow::on_menu_file_new()
{
  std::cout << " New File" << std::endl;
}

void ExampleWindow::on_menu_file_quit()
{
  set_visible(false); //Closes the main window to stop the app->make_window_and_run().
}

void ExampleWindow::on_menu_file_files_dialog()
{
  if (!m_refFileDialog)
  {
    m_refFileDialog = Gtk::FileDialog::create();
    m_refFileDialog->set_modal(true);
  }
  m_refFileDialog->open(*this, sigc::mem_fun(*this, &ExampleWindow::on_dialog_finish));
}

void ExampleWindow::on_dialog_finish(Glib::RefPtr<Gio::AsyncResult>& result)
{
  Glib::RefPtr<Gio::File> file;
  try
  {
    file = m_refFileDialog->open_finish(result);
  }
  catch (const Gtk::DialogError& err)
  {
    std::cout << "No file selected, " << err.what() << std::endl;
    return;
  }

  auto selected_uri = file->get_uri();
  std::cout << "URI selected = " << selected_uri << std::endl;
  std::cout << (m_refRecentManager->has_item(selected_uri) ? "A" : "Not a")
    << " recently used file" << std::endl;
}

File: main.cc (For use with gtkmm 4)

#include "examplewindow.h"
#include <gtkmm/application.h>

int main(int argc, char *argv[])
{
  auto app = Gtk::Application::create("org.gtkmm.example");

  //Shows the window and returns when it is closed.
  return app->make_window_and_run<ExampleWindow>(argc, argv, app);
}

The constructor for ExampleWindow creates the menu and the toolbar using Builder (see Chapter 15, Menus and Toolbars for more information). It then adds the menu and the toolbar to the window.

For any of the FileChooser classes, if you don't wish to display all of the items in the list of files, you can filter the list to show only those that you want. You can filter the list with the help of the FileFilter class. This class allows you to filter files by their name (add_pattern()), or their mime type (add_mime_type()).

After you've created and set up the filter to match only the items you want, you can apply a filter to a chooser widget with the FileChooser::add_filter() function.