mactexshop
I am using TeXShop on a Mac.
Sometimes, I wish to have two separate previews window for my output pdf so that I can look at, for example, page 23, when I edit page 12.
I know there is a small button on the upper right-hand side of preview window which can separate the PDF output into two parts, upper and lower. But what I want is to have two completely separate windows, so that I can put one in one screen and another one on my secondary screen.
Is there any way I can do it?
Let me explain a little more the solution suggested in my above comments. In TeXShop, you can choose which "engine" to call when pressing the Typeset button. An "Engine“ is basically a shell script which calls standard TeX commands, and sometimes much more (see the TeXShop help panel or this post for instance). In your case, modifying the pdfTeX command in the TeXShop Preferences changes the standard LaTeX engine. As a result of your modification, TeXShop cannot open the PDF preview automatically after typesetting. One way to restore this behaviour is to write a new engine.
To do so, you can simply create a shell script containing the following code
#!/bin/bash
pdflatex --output-dir=/tmp "$1"
open -a TeXShop /tmp/$(echo $1 | sed 's/\(.*\)\..*/\1\.pdf/')
Make sure the execution bit is active (chmod +x), change the extension to .engine and move the script to the ~/Library/TeXShop/Engines folder. Launch TeXShop and select your new engine in the popup menu next to the Typeset button, then press Typeset.
There may be a more elegant solution, but this works.
The preview window in TeXShop is created every time you compile your document. You should never really need to use the Open for Preview menu item (in fact, I had no idea it existed or what it did.)
So the typical window layout that most users use is to put their source on one side taking up half of the screen and move the preview window to take up the other half of the screen.
The following key commands are useful to know:
bibtex on your document (or biber if you set that to be the default bibliography program)
You can set the preferences to say how the windows are to be displayed when you re-open TeXShop. The two options are to remember the last position they were in, or to have them all open in fixed positions.
Best Answer
TeXShop has no way to open two views of your PDF file in separate windows. But if you use an external PDF viewer that automatically updates open files when they change, you can easily open your document in the viewer and have that on one screen while the you work on the document in TeXShop at the same time.
Skim is one such PDF viewer (and a really great program). Apple's Preview can also do this. Adobe Reader does not do automatic file refresh, however.