┌────────────────────────────┐
 │ Release notes for i3 v4.0  │
 └────────────────────────────┘

This is the first release of the new major version of i3, v4.0. It has been a
long time since v3.ε was released (over one year). A lot has been happening
since then, we made 736 commits – compare that to the total number of 1664
commits for i3.

The reason for the high number of commits and long time for this release is the
big refactoring we have been doing. Instead of using several lists and a table
as data structures, we now use a single tree of containers. These containers
represent invisible entities like your X11 root window, your different monitors
and workspaces, but also visible entities like actual windows.

Using a tree has made a lot of things cleaner and easier – in the code *and* in
the user interface. Admittedly though, you will probably need a day or two to
get used to a few more advanced movement commands if you are used to v3.ε right
now.

 ┌────────────────────────────┐
 │ New features               │
 └────────────────────────────┘

 • In addition to the proper flex/bison based parser for the config file
   introduced in 3.δ, we now also have a flex/bison parser for commands. What
   this means is that we can have more human-readable, beautiful command names
   instead of cryptic commands like 'f' for fullscreen or 'mh' for move left.
   In fact, the commands for the aforementioned functions *are* 'fullscreen'
   and 'move left'!

 • You can now chain commands using ';' (a semicolon). One example for that is
   'workspace 3 ; exec /usr/bin/urxvt' to switch to a new workspace and open a
   terminal.

 • You can specify which windows should be affected by your command by using
   different criteria. A good example is '[class="Iceweasel"] kill' to get rid
   of all Firefox windows.

 • As the configuration file needs new commands (and a few options are
   obsolete), you need to change it. To make this process a little bit easier
   for you, this release comes with the script i3-migrate-config-to-v4.pl. Just
   run it on your current config file and it will spit out a v4 config file to
   stdout. To make things even better, i3 automatically detects v3 config files
   and calls that script, so you never end up with a non-working config :).

 • Similarly to the criteria when using commands, we now have a 'for_window'
   configuration directive, which lets you automatically apply certain commands
   to certain windows. Use it to set border styles per window, for example with
   'for_window [class="XTerm"] border 1pixel'.

 • Since dock clients (like dzen2) are now part of the layout tree (as opposed
   to a custom data structure as before), it was easy to implement top and
   bottom dock areas. Programs which properly specify the dock hint get placed
   on the edge of the screen they request. i3bar has the -dtop and -dbottom
   parameters, for example.

 • The internal workspace bar is obsolete. Use i3bar instead.

 • Resizing now works between all windows!

 • Fullscreen now works for everything!

 • Floating now works for everything!

 • Your layout is now preserved when doing an inplace restart.

 • When you have an error in your config file, a new program called i3-nagbar
   will tell you so. It offers you two buttons: One to view the error in your
   $PAGER and one to edit your config in your $EDITOR.

 • The default config used key symbols (like 'bind Mod1+f fullscreen') instead
   of key codes. If you use a non-qwerty layout, the program i3-config-wizard
   can create a key symbol based config file based on your current layout. You
   can also chose between Windows (Mod4) and Alt (Mod1) as your default
   modifier. i3-config-wizard will automatically be started as long as you
   don’t have a configuration file for i3.

 • Custom X cursor themes are now supported.

 • The RandR backend now respects the primary output.

 • A wrong 'font' configuration in your config file will no longer make i3
   exit. Instead, it will fall back to a different font and tell you about the
   error in its log.

 • The default split direction (whether a new window gets placed right next to
   the current one or below the current one) is now automatically set to
   horizontal if you have a monitor that is wider than high or vertical if you
   a monitor which is higher than wide. This works great with rotated monitors.

 • Sockets and temporary files are now placed in XDG_RUNTIME_DIR, if set (this
   is used on systemd based systems).

 • Tools like i3bar, i3-msg etc. use the I3_SOCKET_PATH property which is set
   to the X11 root window, so you don’t have to configure your socket path
   anywhere.

 • The kill command kills single windows by default now. To kill a whole
   application, use 'kill client'.

 • IPC: Commands can now have custom replies. When the parser encounters an
   error, a proper error reply is sent.

 • There is now an 'exec_always' configuration directive which works like
   'exec' but will also be run when restarting.

 ┌────────────────────────────┐
 │ Future features            │
 └────────────────────────────┘

Our plans were big but our time and manpower is limited. Therefore, the
following features did not make it into this release. However, the foundation
is now in place and implementing them is possible, so stay tuned!

 • Saving/Restoring specific parts of your layout

 • Session saving

 • Sticky windows

 ┌────────────────────────────┐
 │ Thanks!                    │
 └────────────────────────────┘

Thanks for testing, bugfixes, discussions and everything I forgot go out to:

  aniou, artoj, badboy, cloud, cradle, David Coppa, dbp, dothebart, eeemsi,
  eelvex, f8l, fernando, jan, jimdigriz, jon, julien, kacper, ktosiek,
  lexszero, litemotiv, lourens, madroach, marcus, merovius, mike, mirko, mseed,
  mxf, phnom, quaec, rogutes, sardemff7, smartass, thepub, tiago, tucos,
  woddf2, xpt, ys

-- Michael Stapelberg, 2011-07-24