Case Studies and Examples
The best way to learn how larger programs are constructed is to study them. To that end I am putting together a number of substantial example programs. The amount of documentation may vary from project to project, but t full source code will always be available.
The Tile Game
You'll know the tile game as soon as you see it. This example provides a basic Java/Swing implementation. It is a well documented case study that includes object-oriented design documentation and implementation notes in addition to the full source code.
You can find all the details on the Tile Game here...
Also known as Yet Another Boolean Expression Utility, this is a C# Windows Forms application, but with the really hard work implemented as an embedded Prolog module. Unlike the Tile Game, there is no supporting documentation for this case study, but to make up for that omission there is a comprehensive example of on-line help documentation and a complete DoxyGen API specification.
You can find all the details on YABEU here...
Learning to use 3rd party libraries is an important skill. Although libraries have been a significant part of every programming eco-system, it is probably fair to say that the object-oriented approach makes their use (and design) significantly easier.
You can find some discussion and an example of using Java libraries here...