By Unknown

Gloobus Preview in elementary

Gloobus Preview is a small application, designed to enable a full screen preview of any kind of file, including pdf's, music, movies, and more.
To install Gloobus Preview, paste the following into the terminal.
sudo add-apt-repository ppa:gloobus-dev/gloobus-preview
sudo apt-get update
sudo apt-get install gloobus-preview gloobus-sushi unoconv
To enable Gloobus, open the dconf-editor and navigate to org > pantheon > files > preferences and set /usr/bin/gloobus-preview in the previewer-path.
[NOTE: If you don't have dconf-editor installed, you may get from the terminal: sudo apt-get install dconf-tools.]

Log out and you're set. Press [SPACE] to pull up a preview.
By changing the settings in the upper right corner of any preview window, you can also change the window to match your gtk theme.
The result looks really nice in the elementary environment.
It wasn't without its share of problems. I did get error notifications, but after suppressing the error-reporting for Gloobus, everything appeared to work fine.
Thanks to Chris Horn for the tip!