There's already a question related to State Diagrams, and you've added some feature to globally control text alignment with a skinparam. http://plantuml.sourceforge.net/qa/?qa=3015/left-aligning-transition-text-in-state-diagrams
However, in some cases, namely Sequence Diagrams, I'd like to control how text is aligned on a per-text basis.
For example, in sequence diagrams, the text of messages is always left-aligned. This might be OK for narrow-ish diagrams, but maybe we'd like it to be aligned with the start of the arrow. If a message goes from right to left, then the message text should be right-aligned.
a -> b : Hello world this is a very long message
b -> a : return()
Maybe some syntax that's creole-like, e.g. [[left-aligned[[ or ]]right-aligned]], mabye (( or )) can be used? For instance:
b -> a : ]]return()]]
As usual, thanks for all the quick improvements!!!