Presention at 8th GUADEC, held in Birmingham, UK in 2007

1. 5 tips and 4 and ½ tricks for
porting GNOME applications
to Maemo platform
Eduardo Lima (Etrunko)
8th
GUADEC, Birmingham, UK

2. About INdT
● Instituto Nokia de Tecnologia
● Founded by Nokia do Brasil
● R&D for mobile devices
● About 200 employees
● Partnership with universities
● Three main sites:
– Manaus
– Brasilia
– Recife

3. About INdT – Recife Site
● About 40 employees
● Focused on OSS for mobile devices
– Nokia Internet Tablets (770 and N800)
– S60 smartphones
● Some projects
– Canola
– Python for Maemo
– Tapioca
– Maemo Games
– Maemo SDK VMWare/Qemu Appliances
– Carman
– Mamona
– Gmyth
– Evas optimization

4. Why Porting Applications?
● GNOME is mobile as well

5. Other Reasons
● Bring new experiences to Maemo devices
● Replacement of built-in applications
● All advantages of FOSS
– New features implemented
– Bug fixes and improvements
– Community of users testing and reporting
bugs
● Yet another way to contribute to projects
● “Don't reinvent the wheel!”

6. Some Restrictions
● Small screen (Good resolution)
– Reduced usable area
● Processor power
– 220 MHz (770)
– 320 MHz (N800)
● RAM
– 64 MB (770)
– 128 MB (N800)
– No swap (can be activated)
● DSP

7. Some (more) Restrictions
● Limited storage (JFFS2 helps)
– 128 MB (770)
– 256 MB (N800)
● No FPU in 770
● Power consumption
● Maemo patched libraries
– Old versions
– Can't just be upgraded
● Scratchbox environment

8. First Steps
● Install scratchbox environment
● Install Maemo SDK (i386 and armel)
– Bora for N800
– Gregale for 770
● Find yourself a device (if possible)
● Pick an application
– Study the code
– Find the libraries it depends on

9. Feasibility Of The Port
● Check the dependencies
– libbonobo/libbonoboui
– libgnomeprint/libgnomeprintui
– libgnome/libgnomeui
– libgnomecanvas
– gnomekeyring
● Processor power required
● Storage required
● Memory consumption

10. Getting Rid Of GNOME Stuff
● Some things can just be replaced
– Help
– Icon lookup
● Other things must go within #ifdef blocks
– GnomeProgram
– Session management
– Synchronize accelerators
● Add configure checks for specific bits

11. Example: Gnumeric

12. It Works!

13. Brief Analysis Of The Screen

14. Great Resolution

15. Reduced Usable Area

16. Using The Virtual Keyboard

17. Using The Virtual Keyboard

18. Toolbar

19. Toolbar

20. Virtual Keyboard + Toolbar

21. Virtual Keyboard + Toolbar

22. And so on...

23. And so on...

24. Summary
● Use hildon stuff
– Program/Window
– Menu
– Toolbars
– Tap and hold
– Dialogs (Open, Save, Fonts, Colors, etc)
● Hide anything else
– Status bars
– Other widgets
● Focus on the purpose of the application

25. Hildonization
● Replace the toplevel GtkWindow by a
HildonWindow
● Get a HildonProgram instance
● Add the HildonWindow to HildonProgram
● Change GtkMenuBar to a regular
GtkMenu
● Add GtkMenu to HildonWindow
● Add GtkToolbar objects to HildonWindow
● Add configure checks for Hildon libraries

26. How does it look like?

27. Other tips
● Set application name
– g_set_application_name()
● Unset HildonWindow settings properties
– gtk-button-images and gtk-menu-images
● Register the application with libosso
– osso_initialize() and osso_deinitialize()
– D-Bus service file (/usr/share/dbus-1/services)
● .desktop files go to another location
– /usr/share/applications/hildon

28. Almost finished
● Build packages for everything
– Both i386 and armel targets
● Test the packages in the device
– Scratchbox armel emulation does not work
● Publish the packages, preferably by apt
● Submit patches!

29. Challenges
● Dialogs usually are not developed taking
small screens into account
● Reduce installation size
– Documentation
– Translations
● Debian packaging is boring
● Acceptable performance

30. Other ports (Abiword)

31. Other ports (Evince)

32. Other ports (Gconf Editor)

33. Other ports (Rhythmbox)

34. Other ports (Leafpad)

35. Other ports (Xournal)

37. Thank You!
eduardo.lima@indt.org.br
http://etrunko.blogspot.com