Comment by electroly
8 hours ago
I recall the C++ "fragile base class" problem already starting to rear its ugly head by the end. Existing base classes couldn't be reasonably extended without breaking compatibility with existing applications, and the BeOS API was routinely designed in a way that promoted subclassing. e.g. to implement a window, you'd subclass BWindow and fill it with your own subclasses of BView. It's difficult to see how they would have dug themselves out of this hole in the long term. Perhaps eventually they would have needed to ship multiple versions of their system libraries corresponding to each ABI breakage.
There were other issues too, no? They went all in on multi-threading of the GUI which is super hard to do well, so apps were often crash prone.
I'm not familiar with Be API, but I did a lot of GUI dev in Java Swing back in the day. It's not that hard in principle, you launch whatever background op in whatever threads you like, and any GUI updates have to be done by sending messages back to the GUI event thread (or something like Swing.invokeLater(closure)).
For release 4, we added private impls with many many virtual declaration placeholders. I still remember the comment in every file: Mmmmmmm, stuffing!