The life of a GUI application
Some generalities about the life of a GUI application. What problems are usually encountered as developers, with solutions.ons need to be taken. [...] Once the GUI toolkit (and version) chosen, plus the HIG, the development starts!
One thing to note already is that the application developer is - in practice - limited by what the GUI toolkit provides (and what is easily consumable). Even though it's possible for the app developer to implement custom widgets based on lower-level API, it's much harder to do so and many app developers don't go that route.
So what the GUI toolkit provides shapes what the application looks like, how features are presented to the user and how they are implemented.
We would prefer to have as few frontend code as possible, to focus on the backend and features, but in practice we realize that the frontend is not that easy to implement, after all. A GUI application is not a batch program! Especially if we want to create a real product with a long lifetime, and a revenue stream (incidentally).