Link to explanation of UML terms listed in the diagram toolbox?

I want to create an Activity Diagram. The toolbox offers me items like for example Activity or Action. I know the basics of UML but I’m not sure what VP-UML means with Activity and Action. I want to find out the difference. Where can I have a look for those questions?

It cannot be found very quickly but meanwhile I found after spending much time with searching. Why isn’t it linked in the docs of VP??? Instead the application just gives a link to which explains nothing of the single meaning of each diagram item type. Well, activity and action are quite well explained in the first link I mentioned, so far so good.

Furthermore I want to find out in which cases and in which way I need to use things like Sequence Node, Structured Activity Node, Conditional node (with regions) and Loop node (with regions). Where can I found a good explaination and example diagrams?
Here I’m stranded again even with because 2 sentences explaination per each item type is way far too less for understanding, and there is no example diagram.

  • How do I connect the control flow and data flow for those elements (Inside, Outside to inside, inside to outside)
  • How is each diagram item type processed on code generation???
  • Must I use those elements just within an Activity item or can they be used standalone in the diagram?
  • Why don’t they offer input and output nodes?
  • Why does control flow have the same color as object flow? How can I change that color for object flow in general?
    These are just a few of many questions. Given examples could help a lot but the found examples do not use those more complex diagram item types.

The learning curve cannot be optimal since the documentation is not sufficient to get a fast start. Too much time spending trial and error.

I want to reflect an existing main()-function to an Activity Diagram.

I have some private sub functions in main.c. Do I need to model them as Structured Activities?
I have some calls to methods() of certain classes. Are those ones Actions?
I have some logical groups of initialisation in my main()-function. Are those ones Activities?

Everything must be connected with one control flow path, but I notice that activities doesn’t provide control flow handles on mouse interaction in the editor. I wonder why…

I have no feeling when should I use which diagram item type. Please, help me! What are the rules to reflect existing software in such model (functions, private sub functions, methods of other objects, groups of functions in a logical block)?

I haven’t found any doc about this on the VP web site.

Why does Activity not provide the resource icon for Control Flow?