Since I started developing Oracle Forms within the Forms Developer there has always been an issue that was quite annoying: The fact, that srolling in the object navigator is not possible. But there is a tool out there, which enables additional mouse support called KatMouse. It provides universal mouse scrolling – here the link to download the tool:
After the installation and start of KatMouse it is possible to use the mouse wheel in the Forms Developer which is not a big deal – but it makes life easier. Thanks to my colleague Peter Kopac for the hint.