How to set up key bindings to change file type in Sublime Text 2

You'll need to use the command line option listed in the other answer.

And then add a Shortcut key (aka Hotkey) to that Windows shortcut like so:

1. Make a shortcut to the program itself. You can do this by right clicking somewhere (desktop is easiest, but it doesn't really matter where) and choosing New -> Shortcut. You can also just find Notepad++ in the Start -> (All) Programs menu, right click on the item, copy it from there, and then paste it.

2. Right click the new shortcut you've made (not the one in the Start Menu), choose Properties, and then go to the Shortcut tab. In the Target box you'll have something already there like "C:\Program Files (x86)\Notepad++\notepad++.exe" You need to add your file you wish to open after the quote marks, and then -n## (replacing the #s with the line number). The target box should read something like "C:\Program Files (x86)\Notepad++\notepad++.exe" c:\users\username\desktop\test.txt -n73

3. Stay on the Shortcut tab: there is a box for editing the Shortcut key. Click in there and type a letter. It will automatically add Ctrl+Alt to the front of it, and that is your shortcut key. I'm unsure if you can use any other combination keys for the shortcut key.

Note: LaTeXTools for Sublime Text now supports automatic engine detection if your file starts with %!TEX program = <program>, where <program> is any of pdflatex, xelatex or lualatex. The below instructions are only necessary if you need to manually switch engines for whatever reasons.

Take the LaTeX.sublime-build file in the LaTeXTools folder under ~/Library/Application Support/Sublime Text 2/Packages and copy it to ~/Library/Application Support/Sublime Text 2/Packages/User/, but do it twice and give those files the following name:

• LaTeX.sublime-build.latex
• LaTeX.sublime-build.xetex

Change the files to use the pdflatex for LaTeX and xelatex engines for XeTeX, respectively (as seen in the question).

Then, create a new plugin through Tools » New Plugin… (saving it as switch.py to the location above):

import sublime, sublime_plugin, os, shutil, filecmp

class SwitchCommand(sublime_plugin.ApplicationCommand):
  def run(self):
    folder = os.path.expanduser( \
        '~/Library/Application Support/Sublime Text 2/Packages/User/')
    latex_src = folder + 'LaTeX.sublime-build.latex'
    xetex_src = folder + 'LaTeX.sublime-build.xetex'
    dest = folder + 'LaTeX.sublime-build'

    if filecmp.cmp(dest, latex_src):
      sublime.status_message("Switching to XeTeX")
      shutil.copy(xetex_src, dest)
    else:
      sublime.status_message("Switching to LaTeX")
      shutil.copy(latex_src, dest)

And create a keyboard shortcut for it in Preferences » Key Bindings – User:

[ {
  "keys": ["super+shift+x"], "command": "switch"
} ]

You can also add this to your menu by adding the Main.sublime-menu file to your User package:

[ {
    "id":"tools", "children":
    [ {
        "command": "switch",
        "caption": "Switch between LaTeX/XeTeX"
      }
    ]
} ]

This will now compare the currently active build file with the build settings needed for XeTeX and LaTeX and switch them if necessary.

This could sure use some improvement, but it works for the moment.