I tried to make it as simple as possible. It just displays several lines on the screen and reacts to one hotkey, one right-click menu, and shows one simple hint. There are other things you could do with custom viewers but this should be enough to start. Please consider it as a boilerplate code which you can take and customize for your needs.

It uses the simpleline_place_t class for the data retrieval. This class is derived from the place_t class (custom views can use any class derived from place_t). If you want to create your data dynamically, you will need to derive a class from place_t. Maybe I'll show how to create such a class in another post.

For the impatient, I included the implementation of the simpleline_place_t in the archive. It will give you some idea how difficult it is to write your own. Pretty easy if you ask me ;)