Non-modal AboutDialog
| Chapter 15. Dialogs |

## Non-modal AboutDialog

The `AboutDialog` offers a simple way to display information about a program, like its logo, name, copyright, website and license.

Most dialogs in this chapter are modal, that is, they freeze the rest of the application while they are shown. It's also possible to create a non-modal dialog, which does not freeze other windows in the application. The following example shows a non-modal `AboutDialog`. This is perhaps not the kind of dialog you would normally make non-modal, but non-modal dialogs can be useful in other cases. E.g. gedit's search-and-replace dialog is non-modal.

Reference

### Example

Figure 15.5. AboutDialog

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();
      virtual ~ExampleWindow();

    protected:
      //Signal handlers:
      void on_button_clicked();

      //Child widgets:
      Gtk::Box m_VBox;
      Gtk::Label m_Label;
      Gtk::Box m_ButtonBox;
      Gtk::Button m_Button;
      Gtk::AboutDialog m_Dialog;
    };

    #endif //GTKMM_EXAMPLEWINDOW_H

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

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

    ExampleWindow::ExampleWindow()
    : m_VBox(Gtk::Orientation::VERTICAL),
      m_Label("The AboutDialog is non-modal. "
        "You can select parts of this text while the AboutDialog is shown."),
      m_ButtonBox(Gtk::Orientation::VERTICAL),
      m_Button("Show AboutDialog")
    {
      set_title("Gtk::AboutDialog example");
      set_default_size(400, 150);

      set_child(m_VBox);

      m_VBox.append(m_Label);
      m_Label.set_expand(true);
      m_Label.set_wrap(true);
      m_Label.set_selectable(true);

      m_VBox.append(m_ButtonBox);
      m_ButtonBox.append(m_Button);
      m_Button.set_expand(true);
      m_Button.set_halign(Gtk::Align::CENTER);
      m_Button.set_valign(Gtk::Align::CENTER);
      m_Button.signal_clicked().connect(sigc::mem_fun(*this,
                  &ExampleWindow::on_button_clicked) );

      m_Dialog.set_transient_for(*this);
      m_Dialog.set_hide_on_close();

      m_Dialog.set_logo(Gdk::Texture::create_from_resource("/about/gtkmm_logo.gif"));
      m_Dialog.set_program_name("Example application");
      m_Dialog.set_version("1.0.0");
      m_Dialog.set_copyright("Murray Cumming");
      m_Dialog.set_comments("This is just an example application.");
      m_Dialog.set_license("LGPL");

      m_Dialog.set_website("http://www.gtkmm.org");
      m_Dialog.set_website_label("gtkmm website");

      std::vector<Glib::ustring> list_authors;
      list_authors.push_back("Murray Cumming");
      list_authors.push_back("Somebody Else");
      list_authors.push_back("AN Other");
      m_Dialog.set_authors(list_authors);

      m_Button.grab_focus();
    }

    ExampleWindow::~ExampleWindow()
    {
    }

    void ExampleWindow::on_button_clicked()
    {
      m_Dialog.set_visible(true);

      //Bring it to the front, in case it was already shown:
      m_Dialog.present();
    }

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);
    }

File: `aboutdialog.gresource.xml` (For use with gtkmm 4)

    <?xml version="1.0" encoding="UTF-8"?>
    <gresources>
      <gresource prefix="/about">
        <file>gtkmm_logo.gif</file>
      </gresource>
    </gresources>

FontChooserDialog |  | Chapter 16. The DrawingArea Widget