Each page in tl-setup and tlinstaller is currently responsible for applying proper margins to the page contents. In a perfect world, the margins should be applied centrally by the wizard itself to avoid duplication. As we use factory methods for applying the correct margins, things could definitely be worse. Still, getting rid of the duplicated factory function invocations would still be beneficial.
This issue is seemingly coupled with bug 7953. This coupling is mainly due to some wizard pages consisting of notebooks with only some notebook pages being scrollable. What I see as the neatest and least convoluted approach to this is letting the whole nested notebook be scrollable. This, however, requires at least some foundational work on bug 7953. Other than this, centralizing the page margin application looks fairly trivial.
There is also the alternative of placing a ScrolledWindow within the nested notebook pages that need scrolling. The problem with this is that the scrollbars for these ScrollableWindows would also get the global page margins and would not sit flush against the window border. There is of course the possibility to create a global scrollbar that each nested scrollable notebook page connects to when shown and disconnects from when hidden. I did some playing around with this but my overall feeling is that this approach is pretty error-prone and straight-up ugly as it requires a bunch of duplicated callbacks.
I have a strong suspicion that adding animations to the installer and setup may also get troubled by the nested notebooks. It is also related to this bug in general. So let's add a See Also.
