This is the oxygen-gtk TODO list, maintained and updated by the devs.
You can add anything you can think of here. Possibly specifying the branch, a possible release target, and a priority.
You can also add your name on which of the item you are either already working on, or interested in working on.

Reminder: fixing existing bugs on bugs.kde.org should always have the highest priority :)

Try find a way to avoid flicker on combobox resize (not sure whether this actually is possible or not).

- add hooks at widget realization for registration to the relevant engines, rather than having it scattered in stylewrapper
TRIED, but it actually does not unclutter the code much, and creates other issues. So post-poned.

- better support for using oxygen-gtk in a non-kde environment.

GTK3 branch:

Arrows:
scrollbars: ok
menus: ok.
treeviews: ok
TreeView selection: OK.
Spin buttons: OK

Menu Expander: no selection. OK.

Menus: ok, but:
- issues with scrollbar background
- tearoff menus are totally broken. Part of it might be gtk3 issue. 

Combobox entry: completly fucked up
Seems like gtk3 bug. Also broken with Raleigh. 
TODO: file bug report.

Notebooks:
OK, but vertical positionning of text in tabs is broken. 
Might also be gtk3 bug, but needs investigation.

Icons: customize hover effect, and implement custom disable effect.

ProgressBars
Slider trough
Splitter handles
Toolbar grips

Gtk3-Demo -> offscreen pixmap -> effects 
crash.

Inner shadows:
Implement separate check if a particular GtkScrolledWindow has to be registered to ScrolledWindowEngine to allow for checking before registration (in innerShadowHook as well as in draw_shadow())
Also use composited child hack to round combobox list (and remove old XShape hack for this)

Apply XShape to GtkEntry and GtkComboboxEntry to make it look better on non-oxygen background (e.g. in GtkTextView)