250 lines
9.2 KiB
Plaintext
250 lines
9.2 KiB
Plaintext
i3bar input protocol
|
||
====================
|
||
Michael Stapelberg <michael@i3wm.org>
|
||
August 2012
|
||
|
||
This document explains the protocol in which i3bar expects its input. It
|
||
provides support for colors, urgency, shortening and easy manipulation.
|
||
|
||
== Rationale for choosing JSON
|
||
|
||
Before describing the protocol, let’s cover why JSON is a building block of
|
||
this protocol.
|
||
|
||
1. Other bar display programs such as dzen2 or xmobar are using in-band
|
||
signaling: they recognize certain sequences (like ^fg(#330000) in your input
|
||
text). We would like to avoid that and separate information from
|
||
meta-information. By information, we mean the actual output, like the IP
|
||
address of your ethernet adapter and by meta-information, we mean in which
|
||
color it should be displayed right now.
|
||
2. It is easy to write a simple script which manipulates part(s) of the input.
|
||
Each block of information (like a block for the disk space indicator, a block
|
||
for the current IP address, etc.) can be identified specifically and modified
|
||
in whichever way you like.
|
||
3. It remains easy to write a simple script which just suffixes (or prefixes) a
|
||
status line input, because tools like i3status will output their JSON in
|
||
such a way that each line array will be terminated by a newline. Therefore,
|
||
you are not required to use a streaming JSON parser, but you can use any
|
||
JSON parser and write your script in any programming language. In fact, you
|
||
can decide to not bother with the JSON parsing at all and just inject your
|
||
output at a specific position (beginning or end).
|
||
4. Relying on JSON does not introduce any new dependencies. In fact, the IPC
|
||
interface of i3 also uses JSON, therefore i3bar already depends on JSON.
|
||
|
||
The only point against using JSON is computational complexity. If that really
|
||
bothers you, just use the plain text input format (which i3bar will continue to
|
||
support).
|
||
|
||
== The protocol
|
||
|
||
The first message of the protocol is a header block, which contains (at least)
|
||
the version of the protocol to be used. In case there are significant changes
|
||
(not only additions), the version will be incremented. i3bar will still
|
||
understand the old protocol version, but in order to use the new one, you need
|
||
to provide the correct version. The header block is terminated by a newline and
|
||
consists of a single JSON hash:
|
||
|
||
*Minimal example*:
|
||
------------------------------
|
||
{ "version": 1 }
|
||
------------------------------
|
||
|
||
*All features example*:
|
||
------------------------------
|
||
{ "version": 1, "stop_signal": 10, "cont_signal": 12, "click_events": true }
|
||
------------------------------
|
||
|
||
(Note that before i3 v4.3 the precise format had to be +{"version":1}+,
|
||
byte-for-byte.)
|
||
|
||
What follows is an infinite array (so it should be parsed by a streaming JSON
|
||
parser, but as described above you can go for a simpler solution), whose
|
||
elements are one array per status line. A status line is one unit of
|
||
information which should be displayed at a time. i3bar will not display any
|
||
input until the status line is complete. In each status line, every block will
|
||
be represented by a JSON hash:
|
||
|
||
*Example*:
|
||
------
|
||
[
|
||
|
||
[
|
||
{
|
||
"full_text": "E: 10.0.0.1 (1000 Mbit/s)",
|
||
"color": "#00ff00"
|
||
},
|
||
{
|
||
"full_text": "2012-01-05 20:00:01"
|
||
}
|
||
],
|
||
|
||
[
|
||
{
|
||
"full_text": "E: 10.0.0.1 (1000 Mbit/s)",
|
||
"color": "#00ff00"
|
||
},
|
||
{
|
||
"full_text": "2012-01-05 20:00:02"
|
||
}
|
||
],
|
||
…
|
||
------
|
||
|
||
Please note that this example was pretty printed for human consumption.
|
||
i3status and others will output single statuslines in one line, separated by
|
||
\n.
|
||
|
||
You can find an example of a shell script which can be used as your
|
||
+status_command+ in the bar configuration at
|
||
http://code.stapelberg.de/git/i3/tree/contrib/trivial-bar-script.sh?h=next
|
||
|
||
=== Header in detail
|
||
|
||
version::
|
||
The version number (as an integer) of the i3bar protocol you will use.
|
||
stop_signal::
|
||
Specify to i3bar the signal (as an integer) to send to stop your
|
||
processing.
|
||
The default value (if none is specified) is SIGSTOP.
|
||
cont_signal::
|
||
Specify to i3bar the signal (as an integer)to send to continue your
|
||
processing.
|
||
The default value (if none is specified) is SIGCONT.
|
||
click_events::
|
||
If specified and true i3bar will write a infinite array (same as above)
|
||
to your stdin.
|
||
|
||
=== Blocks in detail
|
||
|
||
full_text::
|
||
The +full_text+ will be displayed by i3bar on the status line. This is the
|
||
only required key.
|
||
short_text::
|
||
Where appropriate, the +short_text+ (string) entry should also be
|
||
provided. It will be used in case the status line needs to be shortened
|
||
because it uses more space than your screen provides. For example, when
|
||
displaying an IPv6 address, the prefix is usually (!) more relevant
|
||
than the suffix, because the latter stays constant when using autoconf,
|
||
while the prefix changes. When displaying the date, the time is more
|
||
important than the date (it is more likely that you know which day it
|
||
is than what time it is).
|
||
color::
|
||
To make the current state of the information easy to spot, colors can
|
||
be used. For example, the wireless block could be displayed in red
|
||
(using the +color+ (string) entry) if the card is not associated with
|
||
any network and in green or yellow (depending on the signal strength)
|
||
when it is associated.
|
||
Colors are specified in hex (like in HTML), starting with a leading
|
||
hash sign. For example, +#ff0000+ means red.
|
||
background::
|
||
Overrides the background color for this particular block.
|
||
border::
|
||
Overrides the border color for this particular block.
|
||
min_width::
|
||
The minimum width (in pixels) of the block. If the content of the
|
||
+full_text+ key take less space than the specified min_width, the block
|
||
will be padded to the left and/or the right side, according to the +align+
|
||
key. This is useful when you want to prevent the whole status line to shift
|
||
when value take more or less space between each iteration.
|
||
The value can also be a string. In this case, the width of the text given
|
||
by +min_width+ determines the minimum width of the block. This is useful
|
||
when you want to set a sensible minimum width regardless of which font you
|
||
are using, and at what particular size.
|
||
align::
|
||
Align text on the +center+, +right+ or +left+ (default) of the block, when
|
||
the minimum width of the latter, specified by the +min_width+ key, is not
|
||
reached.
|
||
name and instance::
|
||
Every block should have a unique +name+ (string) entry so that it can
|
||
be easily identified in scripts which process the output. i3bar
|
||
completely ignores the name and instance fields. Make sure to also
|
||
specify an +instance+ (string) entry where appropriate. For example,
|
||
the user can have multiple disk space blocks for multiple mount points.
|
||
urgent::
|
||
A boolean which specifies whether the current value is urgent. Examples
|
||
are battery charge values below 1 percent or no more available disk
|
||
space (for non-root users). The presentation of urgency is up to i3bar.
|
||
separator::
|
||
A boolean which specifies whether a separator line should be drawn
|
||
after this block. The default is true, meaning the separator line will
|
||
be drawn. Note that if you disable the separator line, there will still
|
||
be a gap after the block, unless you also use +separator_block_width+.
|
||
separator_block_width::
|
||
The amount of pixels to leave blank after the block. In the middle of
|
||
this gap, a separator line will be drawn unless +separator+ is
|
||
disabled. Normally, you want to set this to an odd value (the default
|
||
is 9 pixels), since the separator line is drawn in the middle.
|
||
markup::
|
||
A string that indicates how the text of the block should be parsed. Set to
|
||
+"pango"+ to use https://developer.gnome.org/pango/stable/PangoMarkupFormat.html[Pango markup].
|
||
Set to +"none"+ to not use any markup (default).
|
||
|
||
If you want to put in your own entries into a block, prefix the key with an
|
||
underscore (_). i3bar will ignore all keys it doesn’t understand, and prefixing
|
||
them with an underscore makes it clear in every script that they are not part
|
||
of the i3bar protocol.
|
||
|
||
*Example*:
|
||
------------------------------------------
|
||
{
|
||
"full_text": "E: 10.0.0.1 (1000 Mbit/s)",
|
||
"_ethernet_vendor": "Intel"
|
||
}
|
||
------------------------------------------
|
||
|
||
In the following example, the longest (widest) possible value of the block is
|
||
used to set the minimum width:
|
||
|
||
------------------------------------------
|
||
{
|
||
"full_text": "CPU 4%",
|
||
"min_width": "CPU 100%",
|
||
"align": "left"
|
||
}
|
||
------------------------------------------
|
||
|
||
An example of a block which uses all possible entries follows:
|
||
|
||
*Example*:
|
||
------------------------------------------
|
||
{
|
||
"full_text": "E: 10.0.0.1 (1000 Mbit/s)",
|
||
"short_text": "10.0.0.1",
|
||
"color": "#00ff00",
|
||
"background": "#1c1c1c",
|
||
"border": "#ee0000",
|
||
"min_width": 300,
|
||
"align": "right",
|
||
"urgent": false,
|
||
"name": "ethernet",
|
||
"instance": "eth0",
|
||
"separator": true,
|
||
"separator_block_width": 9
|
||
}
|
||
------------------------------------------
|
||
|
||
=== Click events
|
||
|
||
If enabled i3bar will send you notifications if the user clicks on a block and
|
||
looks like this:
|
||
|
||
name::
|
||
Name of the block, if set
|
||
instance::
|
||
Instance of the block, if set
|
||
x, y::
|
||
X11 root window coordinates where the click occurred
|
||
button::
|
||
X11 button ID (for example 1 to 3 for left/middle/right mouse button)
|
||
|
||
*Example*:
|
||
------------------------------------------
|
||
{
|
||
"name": "ethernet",
|
||
"instance": "eth0",
|
||
"button": 1,
|
||
"x": 1320,
|
||
"y": 1400
|
||
}
|
||
------------------------------------------
|