The document discusses libyui, a library that provides abstraction from GUI and TUI toolkits to allow creating user interfaces that can run on multiple platforms from a single codebase. It demonstrates a simple "Hello World" application in C++, Perl, and Python using libyui. It also covers libyui internals, language bindings, debugging tips, and places to find documentation.

1. 3 UIs for the price of one code with YaST's libyui Katarína Machálková Software Engineer (YaST) [email_address]

3. Talk outline Introduction – why libyui (Hello World!) Brief Tour de Libyui internals My first libyui application Introducing different language bindings Sample non-C++ libyui application Documentation, useful links Questions, answers, ...

4. Intro & Motivation

5. The most famous app of all times ☺

6. Hello World in Qt ... int main(int argc, char *argv[]) { QApplication app(argc, argv); QPushButton hw("Hello World!"); hw.resize(75, 30); QObject::connect(&hw, SIGNAL(clicked()), &app, SLOT(quit())); hw.show(); return app.exec(); }

7. … in Gtk ... int main (int argc, char *argv[]) { GtkWidget *window; GtkWidget *button; gtk_init (&argc, &argv); window = gtk_window_new (GTK_WINDOW_TOPLEVEL); gtk_signal_connect (GTK_OBJECT (window), "destroy", GTK_SIGNAL_FUNC (destroy), NULL); gtk_container_border_width (GTK_CONTAINER (window), 10); button = gtk_button_new_with_label ("Hello World"); gtk_signal_connect (GTK_OBJECT (button), "clicked", GTK_SIGNAL_FUNC (hello), NULL); gtk_signal_connect_object (GTK_OBJECT (button), "clicked", GTK_SIGNAL_FUNC (gtk_widget_destroy), GTK_OBJECT (window)); gtk_container_add (GTK_CONTAINER (window), button); gtk_widget_show (button); gtk_widget_show (window); gtk_main (); return 0; }

8. … and in ncurses ... int main(void) { WINDOW * mainwin; if ( (mainwin = initscr()) == NULL ) { exit(EXIT_FAILURE); } mvaddstr(13, 33, "Hello, world!"); refresh(); sleep(3); delwin(mainwin); endwin(); refresh(); return EXIT_SUCCESS; }

9. One code, three user interfaces! #include "YUI.h" #include "YWidgetFactory.h" #include "YDialog.h" #include "YLayoutBox.h" #include "YEvent.h" int main( int argc, char **argv ) { YDialog *dialog = YUI::widgetFactory()->createPopupDialog(); YLayoutBox *vbox = YUI::widgetFactory()->createVBox( dialog); YUI::widgetFactory()->createLabel( vbox, "Hello, World!" ); YUI::widgetFactory()->createPushButton( vbox, "&OK" ); dialog->waitForEvent(); dialog->destroy(); }

10. Libyui from the inside

12. Provides abstraction from GUI and TUI toolkits (Qt, Gtk, ncurses) in terms of widgets (UI elements) and events

13. YaST user interface engine

14. Independent of YCP (after major rewrite in 2006)

15. Independent of YaST core libraries and libzypp (dtto)

16. Dialogs, widgets + event handling

17. YaST UI Architecture

20. Items

21. Label

22. Current item

26. {

27. YEvent *ev = dialog->waitForEvent();

28. do_something (ev);

31. Reason (selection changed, widget was activated,...)

32. Pointer (or id) of the widget that broke the event loop

34. Signals, slots, callbacks,...

35. Advanced graphics (3D, animations,...)

36. Non-blocking event handling

37. My first libyui application

39. Compiler ( gcc-c++ )

40. YaST UI package ( yast2-[qt|gtk|ncurses] )

41. Favourite text editor / IDE :)

42. Code it ... #include "YUI.h" #include "YWidgetFactory.h" #include "YDialog.h" #include "YLayoutBox.h" #include "YEvent.h" int main( int argc, char **argv ) { YDialog *dialog = YUI::widgetFactory()->createPopupDialog(); YLayoutBox *vbox = YUI::widgetFactory()->createVBox( dialog); YUI::widgetFactory()->createLabel( vbox, "Hello, World!" ); YUI::widgetFactory()->createPushButton( vbox, "&OK" ); dialog->waitForEvent(); dialog->destroy(); }

44. HelloWorld.cc -o HelloWorld'

46. Hello World dissected, part I int main( int argc, char **argv ) { YDialog *dialog = YUI::widgetFactory()->createPopupDialog(); YLayoutBox *vbox = YUI::widgetFactory()->createVBox( dialog); 1 st call creates UI instance and w.factory instance Get widget pointer from w.factory Widget container (layout aid) Child of the main dialog

47. Hello World dissected, part II YUI::widgetFactory()->createLabel( vbox, "Hello, World!" ); YUI::widgetFactory()->createPushButton( vbox, "&OK" ); Create new widget, specify parent + property (string) Vert. container can have many children

48. Hello World dissected, part III dialog->waitForEvent(); dialog->destroy(); } Wait for user input Use this in event loops Close the dialog, do the final cleanup

49. But I don't speak C++ … ?

50. Other scripting language bindings Python Ruby Perl C++ bindings

52. Standard C++ (STL) data types (std::string, std::list,...)

53. Easy way to swig-generated language bindings

54. Currently for perl, python and ruby

55. ' zypper in [perl|python|ruby]-yui ' (that's it ☺ )

56. Hello World with perl-yui !/usr/bin/perl # # Trivial read-write (not write-only :) # example of libyui used from Perl # use yui; my $factory = yui::YUI::widgetFactory; my $dialog = $factory->createPopupDialog; my $vbox = $factory->createVBox( $dialog ); $factory->createLabel( $vbox, "Hello,World!"); $factory->createPushButton( $vbox, "&OK" ); my $event = $dialog->waitForEvent(); $dialog->destroy();

57. Hello World with python-yui # Trivial usage of libyui # in pretty the same way # in python # #!/usr/bin/python import sys import yui factory = yui.YUI.widgetFactory() dialog = factory.createPopupDialog() vbox = factory.createVBox( dialog ) factory.createLabel( vbox, "Hello, World!" ) factory.createPushButton( vbox, "&OK" ) event = dialog.waitForEvent() dialog.destroy()

58. More complex non-C++ application

59. Simple zypp.conf editor with perl-yui (live demonstration)

60. When things don't work ...

63. More Information

64. Where to get more information? On line dokumentace: http://www.suse.de/~ug/ On line dokumentace: http://www.suse.de/~ug/ On line dokumentace: http://www.suse.de/~ug/ On line dokumentace: http://www.suse.de/~ug/ On line dokumentace: http://www.suse.de/~ug/ *-yui package doc with examples: /usr/share/doc/packages/*-yui On line dokumentace: http://www.suse.de/~ug/ On line dokumentace: http://www.suse.de/~ug/ On line dokumentace: http://www.suse.de/~ug/ On line dokumentace: http://www.suse.de/~ug/ On line dokumentace: http://www.suse.de/~ug/ YaST development mailing list: [email_address] General YaST doc (incl. widget reference): http://forgeftp.novell.com/yast/doc/SL11 .1

65. Development tips & tricks

66. Questions & (maybe) answers