How to use Trigger-Channels in openHAB2?

Hi!

tl;dr:
I need to model buttons for a thing and according to the documentation the best way to do this is trigger channels. I cant find any good examples for triggers, so could someone provide some code and xml as sample? I already added some xml and in the Thing description the channel is shown but I cant link anything to it nor is it rendered in the control section in paper ui.

Background:
I’m developing a binding for my personal use: I recently build myselfe a home entertainment system with many devices. I use lirc and a raspi to control them via ir commands. I could use the lirc server and connect it to openhab via a http binding, but that doesnt fit all my needs, same goes for the exec binding: I want to model each of this devices as things. The usual items like SwitchItems and StringItems fit for most porpuses, but I also need to be able to use something just like buttons, which I can directly map to the ir remote command.
Therefor I want to use trigger channels. Bonus question: Can I create my own Items by extending GenericItem and using a own ItemFactory? Would these items be rendered correctly in paper ui out of the box?

Since you’ve mentioned LIRC, you may be interesting in trying my LIRC binding.

JAR of the current version is here: https://drive.google.com/file/d/0By8uaRmIJMCFeUZWWXJIQ2tiZ3M/view?usp=sharing21

Just drop it in the addons folder and it should work.

Instructions on how to use it are available on github: https://github.com/kabili207/smarthome/blob/lirc/extensions/binding/org.eclipse.smarthome.binding.lirc/README.md29