userguide: add popup_during_fullscreen configuration directive

[i3/i3] / docs / userguide

i3 User’s Guide
===============
Michael Stapelberg <michael+i3@stapelberg.de>
July 2011

*********************************************************************************
This document is not yet finished. The tree branch is still in development. The
information provided here should be correct, just not complete yet.
*********************************************************************************

This document contains all the information you need to configure and use the i3
window manager. If it does not, please contact us on IRC (preferred) or post your
question(s) on the mailing list.

//////////////////////////////////////////////////////////////////////////////
== Default keybindings

For the "too long; didn’t read" people, here is an overview of the default
keybindings (click to see the full size image):

*Keys to use with mod (alt):*

image:keyboard-layer1.png["Keys to use with mod (alt)",width=600,link="keyboard-layer1.png"]

*Keys to use with Shift+mod:*

image:keyboard-layer2.png["Keys to use with Shift+mod",width=600,link="keyboard-layer2.png"]

As i3 uses keycodes in the default configuration, it does not matter which
keyboard layout you actually use. The key positions are what matters (of course
you can also use keysymbols, see <<keybindings>>).

The red keys are the modifiers you need to press (by default), the blue keys
are your homerow.
//////////////////////////////////////////////////////////////////////////////

== Using i3

Throughout this guide, the keyword +mod+ will be used to refer to the
configured modifier. This is the alt key (Mod1) by default, with windows (Mod4)
being a popular alternative.

=== Opening terminals and moving around

One very basic operation is opening a new terminal. By default, the keybinding
for this is mod+Enter, that is Alt+Enter in the default configuration. By
pressing mod+Enter, a new terminal will be opened.  It will fill the whole
space available on your screen.

image:single_terminal.png[Single terminal]

If you now open another terminal, i3 will place it next to the current one,
splitting the screen size in half. Depending on your monitor, i3 will put the
new window right to the old window (for widescreen) or below the old window
(rotated displays).

image:two_terminals.png[Two terminals]

To move the focus between the two terminals, you use the direction keys which
you may know from the editor +vi+. However, in i3, your homerow is used for
these keys (in +vi+, the keys are shifted to the left by one for compatibility
with most keyboard layouts). Therefore, +mod+J+ is left, +mod+K+ is down,
+mod+L+ is up and `mod+;` is right. So, to switch between the terminals,
use +mod+K+ or +mod+L+. Of course, you can also use the arrow keys.

At the moment, your workspace is split (it contains two terminals) in a
specific direction (horizontal by default). Every window can be split
horizontally or vertically again, just like the workspace. The terminology is
"window" for a container that actually contains an X11 window (like a terminal
or browser) and "split container" for containers that consist of one or more
windows.

TODO: picture of the tree

To split a window vertically, press +mod+v+. To split it horizontally, press
+mod+h+.

=== Changing the container layout

A split container can have one of the following layouts:

default::
Windows are sized so that every window gets an equal amount of space in the
container.
stacking::
Only the focused window in the container is displayed. You get a list of
windows at the top of the container.
tabbed::
The same principle as +stacking+, but the list of windows at the top is only
a single line which is vertically split.

To switch modes, press +mod+e+ for default, +mod+h+ for stacking and
+mod+w+ for tabbed.

image:modes.png[Container modes]

=== Toggling fullscreen mode for a window

To display a window in fullscreen mode or to go out of fullscreen mode again,
press +mod+f+.

There is also a global fullscreen mode in i3 in which the client will use all
available outputs.

=== Opening other applications

Aside from opening applications from a terminal, you can also use the handy
+dmenu+ which is opened by pressing +mod+d+ by default. Just type the name
(or a part of it) of the application which you want to open. The corresponding
application has to be in your +$PATH+ for this to work.

Additionally, if you have applications you open very frequently, you can
create a keybinding for starting the application directly. See the section
<<configuring>> for details.

=== Closing windows

If an application does not provide a mechanism for closing (most applications
provide a menu, the escape key or a shortcut like +Control+W+ to close), you
can press +mod+Shift+q+ to kill a window. For applications which support
the WM_DELETE protocol, this will correctly close the application (saving
any modifications or doing other cleanup). If the application doesn’t support
the WM_DELETE protocol your X server will kill the window and the behaviour
depends on the application.

=== Using workspaces

Workspaces are an easy way to group a set of windows. By default, you are on
the first workspace, as the bar on the bottom left indicates. To switch to
another workspace, press +mod+num+ where +num+ is the number of the workspace
you want to use. If the workspace does not exist yet, it will be created.

A common paradigm is to put the web browser on one workspace, communication
applications (+mutt+, +irssi+, ...) on another one, and the ones with which you
work, on the third one. Of course, there is no need to follow this approach.

If you have multiple screens, a workspace will be created on each screen at
startup. If you open a new workspace, it will be bound to the screen you
created it on.  When you switch to a workspace on another screen, i3 will set
focus to that screen.

=== Moving windows to workspaces

To move a window to another workspace, simply press +mod+Shift+num+ where
+num+ is (like when switching workspaces) the number of the target workspace.
Similarly to switching workspaces, the target workspace will be created if
it does not yet exist.

=== Resizing

The easiest way to resize a container is by using the mouse: Grab the border
and move it to the wanted size.

See <<resizingconfig>> for how to configure i3 to be able to resize
columns/rows with your keyboard.

=== Restarting i3 inplace

To restart i3 inplace (and thus get into a clean state if there is a bug, or
to upgrade to a newer version of i3) you can use +mod+Shift+r+.

=== Exiting i3

To cleanly exit i3 without killing your X server, you can use +mod+Shift+e+.

=== Floating

Floating mode is the opposite of tiling mode. The position and size of a window
are not managed by i3, but by you. Using this mode violates the tiling
paradigm but can be useful for some corner cases like "Save as" dialog
windows, or toolbar windows (GIMP or similar). Those windows usually set the
appropriate hint and are opened in floating mode by default.

You can enable floating mode for a window by pressing +mod+Shift+Space+. By
dragging the window’s titlebar with your mouse you can move the window
around. By grabbing the borders and moving them you can resize the window. You
can also do that by using the <<floating_modifier>>.

For resizing floating windows with your keyboard, see <<resizingconfig>>.

Floating windows are always on top of tiling windows.

== Tree

i3 stores all information about the X11 outputs, workspaces and layout of the
windows on them in a tree. The root node is the X11 root window, followed by
the X11 outputs, then dock areas and a content container, then workspaces and
finally the windows themselve. In previous versions of i3 we had multiple lists
(of outputs, workspaces) and a table for each workspace. That approach turned
out to be complicated to use (snapping), understand and implement.

=== The tree consists of Containers

The building blocks of our tree are so called +Containers+. A +Container+ can
host a window (meaning an X11 window, one that you can actually see and use,
like a browser). Alternatively, it could contain one or more +Containers+. A
simple example is the workspace: When you start i3 with a single monitor, a
single workspace and you open two terminal windows, you will end up with a tree
like this:

image::tree-layout2.png["layout2",float="right"]
image::tree-shot4.png["shot4",title="Two terminals on standard workspace"]

=== Orientation and Split Containers

[[OrientationSplit]]

It is only natural to use so-called +Split Containers+ in order to build a
layout when using a tree as data structure. In i3, every +Container+ has an
orientation (horizontal, vertical or unspecified). So, in our example with the
workspace, the default orientation of the workspace +Container+ is horizontal
(most monitors are widescreen nowadays). If you change the orientation to
vertical (+mod+v+ in the default config) and *then* open two terminals, i3 will
configure your windows like this:

image::tree-shot2.png["shot2",title="Vertical Workspace Orientation"]

An interesting new feature of the tree branch is the ability to split anything:
Let’s assume you have two terminals on a workspace (with horizontal
orientation), focus is on the right terminal. Now you want to open another
terminal window below the current one. If you would just open a new terminal
window, it would show up to the right due to the horizontal workspace
orientation. Instead, press +mod+v+ to create a +Vertical Split Container+ (to
open a +Horizontal Split Container+, use +mod+h+). Now you can open a new
terminal and it will open below the current one:

image::tree-layout1.png["Layout",float="right"]
image::tree-shot1.png["shot",title="Vertical Split Container"]

unfloat::[]

You probably guessed it already: There is no limit on how deep your hierarchy
of splits can be.

=== Focus parent

Let’s stay with our example from above. We have a terminal on the left and two
vertically split terminals on the right, focus is on the bottom right one. When
you open a new terminal, it will open below the current one.

So, how can you open a new terminal window to the *right* of the current one?
The solution is to use +focus parent+, which will focus the +Parent Container+ of
the current +Container+. In this case, you would focus the +Vertical Split
Container+ which is *inside* the horizontally oriented workspace. Thus, now new
windows will be opened to the right of the +Vertical Split Container+:

image::tree-shot3.png["shot3",title="Focus parent, then open new terminal"]

[[configuring]]
== Configuring i3

This is where the real fun begins ;-). Most things are very dependant on your
ideal working environment so we can’t make reasonable defaults for them.

While not using a programming language for the configuration, i3 stays
quite flexible in regards to the things you usually want your window manager
to do.

For example, you can configure bindings to jump to specific windows,
you can set specific applications to start on specific workspaces, you can
automatically start applications, you can change the colors of i3, and you
can bind your keys to do useful things.

To change the configuration of i3, copy +/etc/i3/config+ to +\~/.i3/config+
(or +~/.config/i3/config+ if you like the XDG directory scheme) and edit it
with a text editor.

On first start (and on all following starts, unless you have a configuration
file), i3 will offer you to create a configuration file. You can tell the
wizard to use either Alt (Mod1) or Windows (Mod4) as modifier in the config
file. Also, the created config file will use the key symbols of your current
keyboard layout. To start the wizard, use the command +i3-config-wizard+.
Please note that you must not have +~/.i3/config+, otherwise the wizard will
exit.

=== Comments

It is possible and recommended to use comments in your configuration file to
properly document your setup for later reference. Comments are started with
a # and can only be used at the beginning of a line:

*Examples*:
-------------------
# This is a comment
-------------------

=== Fonts

i3 uses X core fonts (not Xft) for rendering window titles. You can use
+xfontsel(1)+ to generate such a font description. To see special characters
(Unicode), you need to use a font which supports the ISO-10646 encoding.

If i3 cannot open the configured font, it will output an error in the logfile
and fall back to a working font.

*Syntax*:
------------------------------
font <X core font description>
------------------------------

*Examples*:
--------------------------------------------------------------
font -misc-fixed-medium-r-normal--13-120-75-75-C-70-iso10646-1
--------------------------------------------------------------

[[keybindings]]

=== Keyboard bindings

A keyboard binding makes i3 execute a command (see below) upon pressing a
specific key. i3 allows you to bind either on keycodes or on keysyms (you can
also mix your bindings, though i3 will not protect you from overlapping ones).

* A keysym (key symbol) is a description for a specific symbol, like "a"
  or "b", but also more strange ones like "underscore" instead of "_". These
  are the ones you use in Xmodmap to remap your keys. To get the current
  mapping of your keys, use +xmodmap -pke+.

* Keycodes do not need to have a symbol assigned (handy for custom vendor
  hotkeys on some notebooks) and they will not change their meaning as you
  switch to a different keyboard layout (when using +xmodmap+).

My recommendation is: If you often switch keyboard layouts but you want to keep
your bindings in the same physical location on the keyboard, use keycodes.
If you don’t switch layouts, and want a clean and simple config file, use
keysyms.

*Syntax*:
----------------------------------
bindsym [Modifiers+]keysym command
bindcode [Modifiers+]keycode command
----------------------------------

*Examples*:
--------------------------------
# Fullscreen
bindsym mod+f f

# Restart
bindsym mod+Shift+r restart

# Notebook-specific hotkeys
bindcode 214 exec /home/michael/toggle_beamer.sh
--------------------------------

Available Modifiers:

Mod1-Mod5, Shift, Control::
Standard modifiers, see +xmodmap(1)+

Mode_switch::
Unlike other window managers, i3 can use Mode_switch as a modifier. This allows
you to remap capslock (for example) to Mode_switch and use it for both: typing
umlauts or special characters 'and' having some comfortably reachable key
bindings. For example, when typing, capslock+1 or capslock+2 for switching
workspaces is totally convenient. Try it :-).

[[floating_modifier]]

=== The floating modifier

To move floating windows with your mouse, you can either grab their titlebar
or configure the so called floating modifier which you can then press and
click anywhere in the window itself to move it. The most common setup is to
use the same key you use for managing windows (Mod1 for example). Then
you can press Mod1, click into a window using your left mouse button, and drag
it to the position you want.

When holding the floating modifier, you can resize a floating window by
pressing the right mouse button on it and moving around while holding it. If
you hold the shift button as well, the resize will be proportional.

*Syntax*:
--------------------------------
floating_modifier <Modifiers>
--------------------------------

*Example*:
--------------------------------
floating_modifier Mod1
--------------------------------

=== Layout mode for new containers

This option determines in which mode new containers on workspace level will
start.
///////////////////////////////
See also <<stack-limit>>.
//////////////////////////////

*Syntax*:
---------------------------------------------
workspace_layout <default|stacking|tabbed>
---------------------------------------------
/////////////////////////////////////////////
new_container stack-limit <cols|rows> <value>
/////////////////////////////////////////////

*Example*:
---------------------
workspace_layout tabbed
---------------------

=== Border style for new windows

This option determines which border style new windows will have.

*Syntax*:
---------------------------------------------
new_window <normal|1pixel|borderless>
---------------------------------------------

*Example*:
---------------------
new_window 1pixel
---------------------

=== Variables

As you learned in the section about keyboard bindings, you will have
to configure lots of bindings containing modifier keys. If you want to save
yourself some typing and be able to change the modifier you use later,
variables can be handy.

*Syntax*:
--------------
set $name value
--------------

*Example*:
------------------------
set $m Mod1
bindsym $m+Shift+r restart
------------------------

Variables are directly replaced in the file when parsing. There is no fancy
handling and there are absolutely no plans to change this. If you need a more
dynamic configuration you should create a little script which generates a
configuration file and run it before starting i3 (for example in your
+~/.xsession+ file).

=== Automatically putting clients on specific workspaces

[[assign_workspace]]

It is recommended that you match on window classes insetead of window titles
whenever possible because some applications first create their window, and then
worry about setting the correct title. Firefox with Vimperator comes to mind.
The window starts up being named Firefox, and only when Vimperator is loaded
does the title change. As i3 will get the title as soon as the application maps
the window (mapping means actually displaying it on the screen), you’d need to
have to match on 'Firefox' in this case.

You can prefix or suffix workspaces with a `~` to specify that matching clients
should be put into floating mode. If you specify only a `~`, the client will
not be put onto any workspace, but will be set floating on the current one.

*Syntax*:
------------------------------------------------------------
assign ["]window class[/window title]["] [→] [workspace]
------------------------------------------------------------

*Examples*:
----------------------
assign urxvt 2
assign urxvt → 2
assign urxvt → work
assign "urxvt" → 2
assign "urxvt/VIM" → 3
assign "gecko" → 4
----------------------

Note that the arrow is not required, it just looks good :-). If you decide to
use it, it has to be a UTF-8 encoded arrow, not `->` or something like that.

=== Automatically starting applications on i3 startup

By using the +exec+ keyword outside a keybinding, you can configure
which commands will be performed by i3 on initial startup. +exec+
commands will not run when restarting i3, if you need a command to run
also when restarting i3 you should use the +exec_always+
keyword. These commands will be run in order.

*Syntax*:
-------------------
exec command
exec_always command
-------------------

*Examples*:
--------------------------------
exec i3status | dzen2 -dock
exec_always ~/my_script.sh
--------------------------------

[[workspace_screen]]

=== Automatically putting workspaces on specific screens

If you assign clients to workspaces, it might be handy to put the
workspaces on specific screens. Also, the assignment of workspaces to screens
will determine which workspace i3 uses for a new screen when adding screens
or when starting (e.g., by default it will use 1 for the first screen, 2 for
the second screen and so on).

*Syntax*:
----------------------------------
workspace <number> output <output>
----------------------------------

The 'output' is the name of the RandR output you attach your screen to. On a
laptop, you might have VGA1 and LVDS1 as output names. You can see the
available outputs by running +xrandr --current+.

*Examples*:
---------------------------
workspace 1 output LVDS1
workspace 5 output VGA1
---------------------------

=== Changing colors

You can change all colors which i3 uses to draw the window decorations and the
bottom bar.

*Syntax*:
--------------------------------------------
colorclass border background text
--------------------------------------------

Where colorclass can be one of:

client.focused::
        A client which currently has the focus.
client.focused_inactive::
        A client which is the focused one of its container, but it does not have
        the focus at the moment.
client.unfocused::
        A client which is not the focused one of its container.
client.urgent::
        A client which has its urgency hint activated.
bar.focused::
        The current workspace in the bottom bar.
bar.unfocused::
        All other workspaces in the bottom bar.
bar.urgent::
        A workspace which has at least one client with an activated urgency hint.

You can also specify the color to be used to paint the background of the client
windows. This color will be used to paint the window on top of which the client
will be rendered.

*Syntax*:
-----------------------
client.background color
-----------------------

Only clients that do not cover the whole area of this window expose the color
used to paint it. If you use a color other than black for your terminals, you
most likely want to set the client background color to the same color as your
terminal program's background color to avoid black gaps between the rendered
area of the termianal and the i3 border.

Colors are in HTML hex format (#rrggbb), see the following example:

*Examples*:
--------------------------------------
# class        border  backgr. text
client.focused #2F343A #900000 #FFFFFF
--------------------------------------

Note that for the window decorations, the color around the child window is the
background color, and the border color is only the two thin lines at the top of
the window.

=== Interprocess communication

i3 uses unix sockets to provide an IPC interface. This allows third-party
programs to get information from i3, such as the current workspaces
(to display a workspace bar), and to control i3.

The IPC socket is enabled by default and will be created in
+/tmp/i3-%u/ipc-socket.%p+ where +%u+ is your UNIX username and +%p+ is the PID
of i3.

You can override the default path through the environment-variable +I3SOCK+ or
by specifying the +ipc-socket+ directive.

*Examples*:
----------------------------
ipc-socket /tmp/i3-ipc.sock
----------------------------

You can then use the +i3-msg+ application to perform any command listed in
the next section.

=== Focus follows mouse

If you have a setup where your mouse usually is in your way (like a touchpad
on your laptop which you do not want to disable completely), you might want
to disable 'focus follows mouse' and control focus only by using your keyboard.
The mouse will still be useful inside the currently active window (for example
to click on links in your browser window).

*Syntax*:
----------------------------
focus_follows_mouse <yes|no>
----------------------------

*Example*:
----------------------
focus_follows_mouse no
----------------------

=== Popups during fullscreen mode

When you are in fullscreen mode, some applications still open popup windows
(take Xpdf for example). This is because these applications may not be aware
that they are in fullscreen mode (they do not check the corresponding hint).
There are two things which are possible to do in this situation:

1. Just ignore the popup (don’t map it). This won’t interrupt you while you are
   in fullscreen. However, some apps might react badly to this (deadlock until
   you go out of fullscreen).
2. Leave fullscreen mode. This is the default.

*Syntax*:
-------------------------------------------------
popup_during_fullscreen <ignore|leave_fullscreen>
-------------------------------------------------

*Example*:
------------------------------
popup_during_fullscreen ignore
------------------------------

== List of commands

=== Manipulating layout

To change the layout of the current container to stacking, use +layout
stacking+, for default use +layout default+ and for tabbed, use +layout
tabbed+. To make the current window (!) fullscreen, use +fullscreen+, to make
it floating (or tiling again) use +floating enable+ respectively +floating disable+
(or +floating toggle+):

*Examples*:
--------------
bindsym mod+s layout stacking
bindsym mod+l layout default
bindsym mod+w layout tabbed

# Toggle fullscreen
bindsym mod+f fullscreen

# Toggle floating/tiling
bindsym mod+t floating toggle
--------------

=== Focusing/Moving containers

To change the focus, use the focus command: +focus left+, +focus right+, +focus down+ and +focus up+.

There are a few special parameters you can use for the focus command:

parent::
        Sets focus to the +Parent Container+ of the current +Container+.
child::
        The opposite of +focus parent+, sets the focus to the last focused
        child container.
floating::
        Sets focus to the last focused floating container.
tiling::
        Sets focus to the last focused tiling container.
mode_toggle::
        Toggles between floating/tiling containers.

For moving, use +move left+, +move right+, +move down+ and +move up+.

*Examples*:
----------------------
# Focus clients on the left, bottom, top, right:
bindsym mod+j focus left
bindsym mod+k focus down
bindsym mod+l focus up
bindsym mod+semicolon focus right

# Focus parent container
bindsym mod+u focus parent

# Focus last floating/tiling container
bindsym mod+g focus mode_toggle

# Move client to the left, bottom, top, right:
bindsym mod+j move left
bindsym mod+k move down
bindsym mod+l move up
bindsym mod+semicolon move right
----------------------

=== Changing workspaces/moving containers to workspaces

To change to a specific workspace, use the +workspace+ command, followed by the
number or name of the workspace. To move containers to specific workspaces, use
+move workspace+.

You can also switch to the next and previous workspace with the commands
+workspace next+ and +workspace prev+, which is handy, for example, if you have
workspace 1, 3, 4 and 9 and you want to cycle through them with a single key
combination.

*Examples*:
-------------------------
bindsym mod+1 workspace 1
bindsym mod+2 workspace 2
...

bindsym mod+Shift+1 move workspace 1
bindsym mod+Shift+2 move workspace 2
...
-------------------------

[[resizingconfig]]

=== Resizing containers/windows

If you want to resize containers/windows using your keyboard, you can use the
+resize+ command, I recommend using it inside a so called +mode+:

.Example: Configuration file, defining a mode for resizing
----------------------------------------------------------------------
mode "resize" {
        # These bindings trigger as soon as you enter the resize mode

        # They resize the border in the direction you pressed, e.g.
        # when pressing left, the window is resized so that it has
        # more space on its left

        bindsym j resize shrink left
        bindsym Shift+j resize grow left

        bindsym k resize grow bottom
        bindsym Shift+k resize shrink bottom

        bindsym l resize shrink top
        bindsym Shift+l resize grow top

        bindsym semicolon resize grow right
        bindsym Shift+semicolon resize shrink right

        bindcode 36 mode default
}

# Enter resize mode
bindsym mod+r mode "resize"
----------------------------------------------------------------------

=== Jumping to specific windows

Often when in a multi-monitor environment, you want to quickly jump to a
specific window. For example, while working on workspace 3 you may want to
jump to your mail client to email your boss that you’ve achieved some
important goal. Instead of figuring out how to navigate to your mailclient,
it would be more convenient to have a shortcut. You can use the +focus+ command
with criteria for that.

*Syntax*:
----------------------------------------------------
[class="class"] focus
[title="title"] focus
----------------------------------------------------

*Examples*:
------------------------------------------------
# Get me to the next open VIM instance
bindsym mod+a [class="urxvt" title="VIM"] focus
------------------------------------------------

=== VIM-like marks (mark/goto)

[[vim_like_marks]]

This feature is like the jump feature: It allows you to directly jump to a
specific window (this means switching to the appropriate workspace and setting
focus to the windows). However, you can directly mark a specific window with
an arbitrary label and use it afterwards.  You do not need to ensure that your
windows have unique classes or titles, and you do not need to change your
configuration file.

As the command needs to include the label with which you want to mark the
window, you cannot simply bind it to a key.  +i3-input+ is a tool created
for this purpose: It lets you input a command and sends the command to i3. It
can also prefix this command and display a custom prompt for the input dialog.

*Syntax*:
------------------------------
mark identifier
[con_mark="identifier"] focus
------------------------------

*Example (in a terminal)*:
------------------------------
$ i3-msg mark irssi
$ i3-msg '[con_mark="irssi"] focus'
------------------------------

///////////////////////////////////////////////////////////////////
TODO: make i3-input replace %s
*Examples*:
---------------------------------------
# Read 1 character and mark the current window with this character
bindsym mod+m exec i3-input -p 'mark ' -l 1 -P 'Mark: '

# Read 1 character and go to the window with the character
bindsym mod+g exec i3-input -p 'goto ' -l 1 -P 'Goto: '
---------------------------------------

Alternatively, if you do not want to mess with +i3-input+, you could create
seperate bindings for a specific set of labels and then only use those labels.
///////////////////////////////////////////////////////////////////

=== Changing border style

To change the border of the current client, you can use +border normal+ to use the normal
border (including window title), +border 1pixel+ to use a 1-pixel border (no window title)
and +border none+ to make the client borderless.

There is also +border toggle+ which will toggle the different border styles.

*Examples*:
----------------------------
bindsym mod+t border normal
bindsym mod+y border 1pixel
bindsym mod+u border none
----------------------------

[[stack-limit]]

///////////////////////////////////////////////////////////////////////////////
TODO: not yet implemented
=== Changing the stack-limit of a container

If you have a single container with a lot of windows inside it (say, more than
10), the default layout of a stacking container can get a little unhandy.
Depending on your screen’s size, you might end up with only half of the title
lines being actually used, wasting a lot of screen space.

Using the +stack-limit+ command, you can limit the number of rows or columns
in a stacking container. i3 will create columns or rows (depending on what
you limited) automatically as needed.

*Syntax*:
--------------------------------
stack-limit <cols|rows> <value>
--------------------------------

*Examples*:
-------------------
# I always want to have two window titles in one line
stack-limit cols 2

# Not more than 5 rows in this stacking container
stack-limit rows 5
-------------------

image:stacklimit.png[Container limited to two columns]
///////////////////////////////////////////////////////////////////////////////

=== Reloading/Restarting/Exiting

You can make i3 reload its configuration file with +reload+. You can also
restart i3 inplace with the +restart+ command to get it out of some weird state
(if that should ever happen) or to perform an upgrade without having to restart
your X session. To exit i3 properly, you can use the +exit+ command,
however you don’t need to (simply killing your X session is fine as well).

*Examples*:
----------------------------
bindsym mod+Shift+r restart
bindsym mod+Shift+w reload
bindsym mod+Shift+e exit
----------------------------

[[multi_monitor]]

== Multiple monitors

As you can see in the goal list on the website, i3 was specifically developed
with support for multiple monitors in mind. This section will explain how to
handle multiple monitors.

When you have only one monitor, things are simple. You usually start with
workspace 1 on your monitor and open new ones as you need them.

When you have more than one monitor, each monitor will get an initial
workspace.  The first monitor gets 1, the second gets 2 and a possible third
would get 3. When you switch to a workspace on a different monitor, i3 will
switch to that monitor and then switch to the workspace. This way, you don’t
need shortcuts to switch to a specific monitor, and you don’t need to remember
where you put which workspace. New workspaces will be opened on the currently
active monitor.  It is not possible to have a monitor without a workspace.

The idea of making workspaces global is based on the observation that most
users have a very limited set of workspaces on their additional monitors.
They are often used for a specific task (browser, shell) or for monitoring
several things (mail, IRC, syslog, …). Thus, using one workspace on one monitor
and "the rest" on the other monitors often makes sense. However, as you can
create an unlimited number of workspaces in i3 and tie them to specific
screens, you can have the "traditional" approach of having X workspaces per
screen by changing your configuration (using modes, for example).

=== Configuring your monitors

To help you get going if you have never used multiple monitors before, here is
a short overview of the xrandr options which will probably be of interest to
you. It is always useful to get an overview of the current screen configuration.
Just run "xrandr" and you will get an output like the following:
-------------------------------------------------------------------------------
$ xrandr
Screen 0: minimum 320 x 200, current 1280 x 800, maximum 8192 x 8192
VGA1 disconnected (normal left inverted right x axis y axis)
LVDS1 connected 1280x800+0+0 (normal left inverted right x axis y axis) 261mm x 163mm
   1280x800       60.0*+   50.0
   1024x768       85.0     75.0     70.1     60.0
   832x624        74.6
   800x600        85.1     72.2     75.0     60.3     56.2
   640x480        85.0     72.8     75.0     59.9
   720x400        85.0
   640x400        85.1
   640x350        85.1
--------------------------------------------------------------------------------------

Several things are important here: You can see that +LVDS1+ is connected (of
course, it is the internal flat panel) but +VGA1+ is not. If you have a monitor
connected to one of the ports but xrandr still says "disconnected", you should
check your cable, monitor or graphics driver.

The maximum resolution you can see at the end of the first line is the maximum
combined resolution of your monitors. By default, it is usually too low and has
to be increased by editing +/etc/X11/xorg.conf+.

So, say you connected VGA1 and want to use it as an additional screen:
-------------------------------------------
xrandr --output VGA1 --auto --left-of LVDS1
-------------------------------------------
This command makes xrandr try to find the native resolution of the device
connected to +VGA1+ and configures it to the left of your internal flat panel.
When running "xrandr" again, the output looks like this:
-------------------------------------------------------------------------------
$ xrandr
Screen 0: minimum 320 x 200, current 2560 x 1024, maximum 8192 x 8192
VGA1 connected 1280x1024+0+0 (normal left inverted right x axis y axis) 338mm x 270mm
   1280x1024      60.0*+   75.0
   1280x960       60.0
   1152x864       75.0
   1024x768       75.1     70.1     60.0
   832x624        74.6
   800x600        72.2     75.0     60.3     56.2
   640x480        72.8     75.0     66.7     60.0
   720x400        70.1
LVDS1 connected 1280x800+1280+0 (normal left inverted right x axis y axis) 261mm x 163mm
   1280x800       60.0*+   50.0
   1024x768       85.0     75.0     70.1     60.0
   832x624        74.6
   800x600        85.1     72.2     75.0     60.3     56.2
   640x480        85.0     72.8     75.0     59.9
   720x400        85.0
   640x400        85.1
   640x350        85.1
-------------------------------------------------------------------------------
Please note that i3 uses exactly the same API as xrandr does, so it will see
only what you can see in xrandr.

See also <<presentations>> for more examples of multi-monitor setups.

=== Interesting configuration for multi-monitor environments

There are several things to configure in i3 which may be interesting if you
have more than one monitor:

1. You can specify which workspace should be put on which screen. This
   allows you to have a different set of workspaces when starting than just
   1 for the first monitor, 2 for the second and so on. See
   <<workspace_screen>>.
2. If you want some applications to generally open on the bigger screen
   (MPlayer, Firefox, …), you can assign them to a specific workspace, see
   <<assign_workspace>>.
3. If you have many workspaces on many monitors, it might get hard to keep
   track of which window you put where. Thus, you can use vim-like marks to
   quickly switch between windows. See <<vim_like_marks>>.

== i3 and the rest of your software world

=== Displaying a status line

A very common thing amongst users of exotic window managers is a status line at
some corner of the screen. It is an often superior replacement to the widget
approach you have in the task bar of a traditional desktop environment.

If you don’t already have your favorite way of generating such a status line
(self-written scripts, conky, …), then i3status is the recommended tool for
this task. It was written in C with the goal of using as few syscalls as
possible to reduce the time your CPU is woken up from sleep states.

Regardless of which application you use to generate the status line, you
want to make sure that the application does one of the following things:

1. Register as a dock window using EWMH hints. This will make i3 position the
   window above the workspace bar but below every other client. This is the
   recommended way, but in case of dzen2, for example, you need to check out
   the source of dzen2 from subversion, as the -dock option is not present
   in the released versions.
2. Overlay the internal workspace bar. This method will not waste any space
   on the workspace bar, however, it is rather hackish. Just configure
   the output window to be over the workspace bar (say -x 200 and -y 780 if
   your screen is 800 px height).

The planned solution for this problem is to make the workspace bar optional
and switch to a third party application completely (dzen2 for example)
which will then contain the workspace bar.

=== Giving presentations (multi-monitor)

When giving a presentation, you typically want the audience to see what you see
on your screen and then go through a series of slides (if the presentation is
simple). For more complex presentations, you might want to have some notes
which only you can see on your screen, while the audience can only see the
slides.

[[presentations]]
==== Case 1: everybody gets the same output
This is the simple case. You connect your computer to the video projector,
turn on both (computer and video projector) and configure your X server to
clone the internal flat panel of your computer to the video output:
-----------------------------------------------------
xrandr --output VGA1 --mode 1024x768 --same-as LVDS1
-----------------------------------------------------
i3 will then use the lowest common subset of screen resolutions, the rest of
your screen will be left untouched (it will show the X background). So, in
our example, this would be 1024x768 (my notebook has 1280x800).

==== Case 2: you can see more than your audience
This case is a bit harder. First of all, you should configure the VGA output
somewhere near your internal flat panel, say right of it:
-----------------------------------------------------
xrandr --output VGA1 --mode 1024x768 --right-of LVDS1
-----------------------------------------------------
Now, i3 will put a new workspace (depending on your settings) on the new screen
and you are in multi-monitor mode (see <<multi_monitor>>).

Because i3 is not a compositing window manager, there is no ability to
display a window on two screens at the same time. Instead, your presentation
software needs to do this job (that is, open a window on each screen).