Scripting page-turns in a pdf

Question

I'd like to move between pages in a pdf, by means of a hotkey or similar, without switching focus to the pdf app (e.g., Preview). This would be useful for taking notes in a text editor, for example, where I want to retain the focus on the editor but easily turn pdf pages as I read and take notes.
I thought this would be an easy thing to script using Automator or AppleScript but I can't figure it out. While it would be nice to pull this off using Preview, I'm not opposed to using another (cheap or free) pdf app to do it, if that's what it takes to expose the page-turning commands. Any ideas?

Answer 1

Preview is not scriptable, and trying to GUI script it requires bringing it to the foreground.  you could do something like this:
tell application "System Events"
          set oldFrontApp to item 1 of (every process whose frontmost is true)
          tell process "Preview"
                    set frontmost to true
  key code 121
          end tell
          set frontmost of oldFrontApp to true
end tell
which brings it to the front, scrolls it, then sends it back, but it's a little annoying to watch.
You could try Skim, which is scriptable, and a good app for note-taking regardless.  Or you could recall that you can hold down the command key while clicking on the scrollbar of a background window or rolling the mouse wheel over it, and that will scroll it without bringing it forward.