Chapter 16. Dialogs

Table of Contents

Dialogs are used as secondary windows, to provide specific information or to ask questions. Gtk::Dialog windows contain a few pre-packed widgets to ensure consistency, and a run() method which blocks until the user dismisses the dialog.

There are several derived Dialog classes which you might find useful. Gtk::MessageDialog is used for most simple notifications. But at other times you might need to derive your own dialog class to provide more complex functionality.

To pack widgets into a custom dialog, you should pack them into the Gtk::Box, available via get_content_area(). To just add a Button to the bottom of the Dialog, you could use the add_button() method.

The run() method returns an int. This may be a value from the Gtk::ResponseType if the user closed the dialog by clicking a standard button, or it could be the custom response value that you specified when using add_button().

Reference

MessageDialog

MessageDialog is a convenience class, used to create simple, standard message dialogs, with a message, an icon, and buttons for user response. You can specify the type of message and the text in the constructor, as well as specifying standard buttons via the Gtk::ButtonsType enum.

Reference

Example

Figure 16.1. MessageDialog

Source Code

File: examplewindow.h (For use with gtkmm 3, not gtkmm 2)

#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_info_clicked();
  void on_button_question_clicked();

  //Child widgets:
  Gtk::ButtonBox m_ButtonBox;
  Gtk::Button m_Button_Info, m_Button_Question;
};

#endif //GTKMM_EXAMPLEWINDOW_H

File: main.cc (For use with gtkmm 3, not gtkmm 2)

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

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

  ExampleWindow window;

  //Shows the window and returns when it is closed.
  return app->run(window);
}

File: examplewindow.cc (For use with gtkmm 3, not gtkmm 2)

#include "examplewindow.h"
#include <gtkmm/messagedialog.h>
#include <iostream>


ExampleWindow::ExampleWindow()
: m_ButtonBox(Gtk::ORIENTATION_VERTICAL),
  m_Button_Info("Show Info MessageDialog"),
  m_Button_Question("Show Question MessageDialog")
{
  set_title("Gtk::MessageDialog example");

  add(m_ButtonBox);

  m_ButtonBox.pack_start(m_Button_Info);
  m_Button_Info.signal_clicked().connect(sigc::mem_fun(*this,
              &ExampleWindow::on_button_info_clicked) );

  m_ButtonBox.pack_start(m_Button_Question);
  m_Button_Question.signal_clicked().connect(sigc::mem_fun(*this,
              &ExampleWindow::on_button_question_clicked) );

  show_all_children();
}

ExampleWindow::~ExampleWindow()
{
}

void ExampleWindow::on_button_info_clicked()
{
  Gtk::MessageDialog dialog(*this, "This is an INFO MessageDialog");
  dialog.set_secondary_text(
          "And this is the secondary text that explains things.");

  dialog.run();
}

void ExampleWindow::on_button_question_clicked()
{
  Gtk::MessageDialog dialog(*this, "This is a QUESTION MessageDialog",
          false /* use_markup */, Gtk::MESSAGE_QUESTION,
          Gtk::BUTTONS_OK_CANCEL);
  dialog.set_secondary_text(
          "And this is the secondary text that explains things.");

  int result = dialog.run();

  //Handle the response:
  switch(result)
  {
    case(Gtk::RESPONSE_OK):
    {
      std::cout << "OK clicked." << std::endl;
      break;
    }
    case(Gtk::RESPONSE_CANCEL):
    {
      std::cout << "Cancel clicked." << std::endl;
      break;
    }
    default:
    {
      std::cout << "Unexpected button clicked." << std::endl;
      break;
    }
  }
}


Chapter 15. Widgets Without X-Windows		FileChooserDialog