When I click on items in my Calibre list, they open in the program my OS has them associated with, e.g., .pdf opens in Adobe Reader, and .txt opens in notepad. I'd like to change this so that, for example, clicking on a .txt file in the list will open it in yBook reader. I want to leave my OS associations the same---when clicking on a .txt file in my file manager, I almost always want it to open in notebook, but an ebook in .txt format is a different thing. It seems this bug was noted thirteen months ago:
http://oldbugs.calibre-ebook.com/ticket/5265
It seems like it should be a simple matter. Is there any way Calibre can do this?