Flitter

Flitter makes launching apps and switching between windows as fast and easy as possible:

• F1 launches Firefox, or focuses the Firefox window if Firefox is already running.
• If there's more than one Firefox window open, repeatedly hitting F1 cycles through them.
• F2 does the same for gVim.
• And so on, binding all your most-frequently used apps to the function keys or other keyboard shortcuts (you configure the apps and shortcuts yourself).
• I have F1..F10 bound to my 10 most frequently used apps, and F11 cycling through all other windows that don't belong to my top ten apps.
• When moving between apps Flitter raises each app's most recently used window first, and when cycling through an app's windows it goes through them in most-recently-used-first order.

Compared to using the mouse or traditional fast window switching shortcuts (like Alt-Tab), with Flitter:

• You don't need to keep track of which apps are open and closed. Let the computer do that. F1 just takes you to Firefox, opening it if necessary. You can only Alt-Tab to an app if it's open, if not you have to do something else to launch it.
• You never need to use the mouse to open apps or switch windows.
• You never need to use two hands or two finger contortions to press multiple keys at once (Alt+Tab, Tab, Tab...). Just hit one function key.
• You only need to use one key (perhaps hitting it repeatedly) to get to a window, no Alt+Tab,Tab,Tab to get to an app then Alt+`,`,` or Alt+down,left,left to get to the window.
• You don't need to look at or think about anything on screen other than the app windows themselves as they're focused (no finding the right icon in an Alt-Tab dialog)
• Very finger memory compatible, your hands will quickly memorize F1 for Firefox, F5 for Thunderbird, F8 for Skype, and you'll be switching apps at the speed of thought.

Repeatedly hitting F1 to cycle through Firefox windows doesn't scale well if you have dozens of Firefox windows open. But personally I usually have just one, and never more than three or four, windows per app (and then sometimes several tabs within each window) and Flitter works great for me (focusing the most recently used windows first makes a big difference).

Binding each function key to an app doesn't scale when you have more apps than function keys. You can just fall back on Alt-Tab for apps outside of your top 12, but flitter --others (see below) gives you a key for cycling through windows that don't belong to any of your bound apps. I find this lets me avoid Alt-Tab entirely.

Requirements

Flitter requires Python 2.7, wmctrl and works with any WMH/NetWM compatible X Window Manager (Gnome, Unity, Openbox...)

It doesn't work on Windows, OS X, or non-WMH/NetWM linux environments yet, although porting should be possible (just replace wmctrl.py with something capable of interacting with your desktop's windows).

Installation

First install wmctrl. On Debian or Ubuntu, just:

$ sudo apt-get install wmctrl

Then install Flitter:

$ pip install flitter

You should now be able to run the flitter command in your shell. Run flitter -h for help.

Configuration & Usage

Copy the default configuration file to ~/.flitter.json. This is a JSON file containing a list of window specs. Window specs are how Flitter knows which windows belong to which app. Each spec has a name, such as Firefox, and a number of properties that are matched against the properties of your open windows to decide whether each window is a Firefox window or not. For example:

    "Firefox": {
        "wm_class": ".Firefox",
        "command": "firefox"
    },

This window spec will match all windows whose WM_CLASS property contains the string ".Firefox" (in other words, all Firefox windows).

To have Flitter raise a Firefox window or launch Firefox, run it with the spec's name as the command-line argument:

$ flitter firefox

Flitter doesn't have built-in support for keyboard shortcuts. You just use whatever mechanism your window manager provides to bind keyboard shortcuts to flitter commands.

To see a list of all your open windows and their properties so you can write window specs for them, run wmctrl -lxp (see man wmctrl for more info).

The "command" part of the spec is the command that Flitter will run to launch Firefox, if it finds no Firefox windows.

This way of identifying windows is quite flexible. You can go beyond the simple one app per keyboard shortcut model, for example:

• A key to switch to the Firefox window showing Google Calender or open Google Calender in a new Firefox window
• A key to switch to the Gnome Terminal window running WeeChat or open a new Gnome Terminal window with the WeeChat profile

The full set of attributes that you can include in a window spec is:

window_id The unique ID of an open window, e.g. 0x0180000b

desktop The desktop that the window is on, e.g. 1

pid The process ID of the window, e.g. 3384

wm_class The WM_CLASS of the window, e.g. Navigator.Firefox

machine The client machine that the window belongs to

title The window title

Development Install

To install Flitter in a virtual environment for development first install virtualenv, on Debian or Ubuntu do:

$ sudo apt-get install python-virtualenv

Then create and activate a Python virtual environment and install Flitter into it:

$ virtualenv flitter
$ . flitter/bin/activate
$ cd flitter
$ pip install -e 'git+https://github.com/seanh/flitter.git#egg=flitter'

which flitter should now report the flitter binary in your virtualenv.

To run the tests do:

$ cd src/flitter
$ pip install -r dev-requirements.txt
$ nosetests

To run the tests and produce a test coverage report, do:

$ nosetests --with-coverage --cover-inclusive --cover-erase --cover-tests

To upload a new release of Flitter to PyPI ans GitHub:

1. Update the version number in setup.py.
2. python setup.py sdist
3. python setup.py sdist upload
4. git commit setup.py -m "Release version X.Y.Z"
5. git tag X.Y.Z
6. git push
7. git push --tags