application development - Photo selector API for Ubuntu Touch

I searched all over the web, but I can't find anything that could help me. I am looking for an API to implement a photo selector in my Ubuntu Touch application. I need something like a File Chooser dialog which would allow me to select photo files from across the filesystem.

Does something like this exist??

I have seen a way to do it in https://launchpad.net/ubuntu-read. You should have a look at it.