Rotation and scale locked?

A bit frustrating. I've spent a few hours working on a model. I wanted to set up a camera angle to do a test render only to find the camera can't rotate, In fact nothing will rotate or scale unless I'm in edit mode and have the entire part highlighted. Why suddenly I can't scale or rotate anything is a mystery right now.
I'm pretty sure that wasn't a problem when I began the file. I first noticed it when I brought in an eyeball from another file to use with the model. I couldn't scale it or turn it unless I was in edit.

I'm not ruling out my hitting a wrong key at some point. My fingers are used to Photoshop/Ae shortcuts, and I accidentally reach for the space bar to move sometimes, as well as assorted other moves assigned to different keys.

Just as important as learning how to perform all the functions you'll need is knowing how to back out of various accidents. I'm not sure how I caused this but it'd be good to know how to fix it.