*Before proceeding, be aware that I deprecated this polybar config on August 22nd, 2020, meaning I won’t update it anymore unless I use it again some day in the future. I will keep it on my website though.*
Polybar is a desktop utility for displaying various information in form of bars for GNU/Linux systems. It is often used as a replacement for native bars available in window managers, such as i3. In my case, I use two instances of polybar in order to get two bars displayed on each screen. The information displayed is either related to i3 itself, or it is system information, such as CPU or disk usage. More information will be given and explained below.
If you want to learn more about how to configure Polybar, you can go to its [[https://github.com/jaagr/polybar][official repository on Github]].
#+BEGIN_EXPORT latex
Be aware that this PDF documents suffers from a couple of issues with some characters such as emojis. If you wish to see everything correctly, I would suggest you to take a look at the online HTML version of this document.
Like most status bars available, we can declare custom colors to be used in polybar. This part of the configuration file is declared with the following header:
As I use pywal as a color scheme generator based on the color of my wallpaper, I need to tell polybar to fetch the colors it will use from xrdb. If such color cannot be used, other colors will be used as fallback colors. First, let’s declare our default background and foreground colors with their alternative option.
#+BEGIN_SRC conf-windows
background = ${xrdb:color1:#50000000}
background-alt = ${xrdb:color2:#444}
foreground = ${xrdb:color7:#dfdfdf}
foreground-alt = ${xrdb:color6:#555}
#+END_SRC
Now, we can also declare our primary and secondary colors.
#+BEGIN_SRC conf-windows
primary = #ffb52a
secondary = #e60053
#+END_SRC
Polybar is also aware of alerts sent by window managers such as i3 when a window opens in an unfocused workspace. For that, let’s declare an alert color.
It is possible in i3 to declare as many bars as we wish, and each of these bars will be named. Naming the bar is done in its module declaration like so:
We need to set on which screen the bar is to be displayed. Indeed, it is possible to display a bar on only one specific screen if we wish to. Actually, it is even the default behavior of polybar, but as we will see later with the launching script, it is possible to launch bars on multiple outputs at the same time. Here, we simply get the value of the variable ~monitor~ from the launch environment.
#+NAME: monitor-bar
#+BEGIN_SRC conf-windows
monitor = ${env:MONITOR}
#+END_SRC
We have a few position-related variables that need to be set. We can specify whether or not we want our bar at the bottom of the screen —which is the default behavior of polybar—, its width, its height, the radius for the rounding of its corners and whether the bar should be centered or not. In my case, my bars are rather small height-wise, and it occupies most of the width of my screens. There is some gaps between this bar and the border of the screen, but this is due to a border around the bar itself which acts not only on the width of the bar itself, but also on its height.
#+BEGIN_SRC conf-windows
bottom = false
border-size = 5
<<position-bar-top>>
#+END_SRC
#+NAME: position-bar-top
#+BEGIN_SRC conf-windows :exports none :tangle no
width = 100%
height = 22
radius = 10.0
fixed-center = true
#+END_SRC
We also want to add some padding to our bar so our modules are not too close to its edges, especially due to the rounding of the top bar.
#+NAME: padding-bar
#+BEGIN_SRC conf-windows
padding-left = 2
padding-right = 4
#+END_SRC
Each module will have some padding around it, so that modules aren’t glued together and instead have some room to breathe. The padding on the left is a bit less than the padding on the right for aesthetic reasons.
#+NAME: module-margin-bar
#+BEGIN_SRC conf-windows
module-margin-left = 1
module-margin-right = 2
#+END_SRC
The top bar doesn’t include any system tray, so let’s disable that.
As explained above, we declared some global variables when it comes to colors, and this is where they will be used. The bar’s background will be of the same color as the main background color declared earlier, and the same goes for the foreground.
#+NAME: bar-colors
#+BEGIN_SRC conf-windows
background = ${colors.background}
foreground = ${colors.foreground}
#+END_SRC
If we wanted, we could also declare a default color for the underlines under the various modules that will be included in the bar, but in our case this variable is unused. So we will simply add this commented line as a memento this is possible, but it won’t have any effect with this current configuration of polybar. Same goes for the border around the bar, it is a useless variable in this configuration since we want the border to be transparent.
#+NAME: line-border-color
#+BEGIN_SRC conf-windows
line-color = #f00
; border-color = #00000000
#+END_SRC
Although the variable for the default line color is not used, we still have to set the default width of the underline of our modules. By default, their underline will be three pixels thick.
Now we can chose which font fill be used in order to display text in this bar, as well as the locale we want. The locale will be useful for displaying information such as date and time, which is a module we will have in this top bar. First, the declaration of the locale is done like so:
#+NAME: locale-bar
#+BEGIN_SRC conf-windows
locale = ja_JP.UTF-8
#+END_SRC
Now, we can declare the fonts we want to use in Polybar. It is possible to declare several of them, the first one is the one which gets the absolute priority, and the next ones with a larger index are fallback fonts. Font declaration accepts the fontconfig format as well as possible offset[fn:1]. Five fonts are used in my polybar config:
#+NAME: fonts-polybar
| Font | fontconfig | Vertical offset | Why it’s used |
Finally, arguably one of the most important parts of our bar configuration: the module selection. Modules can be positioned in three different parts of our bar: to the right, in middle or to the left. On the left, we want our workspace indicator for i3. In the middle, we’ll get the title of the focused window, and to the left we’ll have the date and time.
#+NAME: modules-generate
#+BEGIN_SRC emacs-lisp :var table=top-modules :results value :cache yes
The variables are the same as above, but two of them will be slightly modified:
#+BEGIN_SRC conf-windows
bottom = true
border-size = 0
<<position-bar-bottom>>
#+END_SRC
#+NAME: position-bar-bottom
#+BEGIN_SRC conf-windows :exports none :tangle no
width = 100%
height = 22
radius = 0.0
fixed-center = true
#+END_SRC
When it comes to the bottom bar, I prefer to have it fit my outputs, without any margin around it. And of course, I have to declare it as being at the bottom of the screen, hence these modifications. As regards the padding of our modules, their own margins, and the screen output, they aren’t modified.
#+BEGIN_SRC conf-windows
<<padding-bar>>
<<module-margin-bar>>
<<monitor-bar>>
#+END_SRC
However, we do display the system tray on this bottom bar at its right. It has no padding and it is not detached from the bar (this allows the bar to be displayed under the icons of the system tray), and their maximum size was chosen so they are well visible without being too big.
Nothing changes from the top bar, all the variables stay with the same values. See [[#Declaration_of_the_bars-Bottom_bar_declaration-Colors_and_display-854aae82][Colors and display]] of the top bar for more information.
Again, nothing changes from the top bar, so for more info on what’s going on, see [[#Declaration_of_the_bars-Top_bar_declaration-Fonts_and_locale-70a25466][Fonts and locale]] of the top bar.
Now, we can get to something interesting again: modules. This bar has a lot more modules than the top bar. Here is the list of the modules we have on the bottom bar:
Before we begin to describe the different modules, I would like to point out something that will be repeated multiple times if I don’t talk about it right now: for each module, it is possible to declare the foreground and background color of the prefix of the modules, as well as the underline color and the padding of the module. I like these parameters to be rather consistent, so the code block you will see below will often be reused. The colors refer to the colors declared earlier, and the padding is minimal.
This module allows the user to get a battery widget among the polybar modules that will also send a notification to the user if the battery level drops below a certain value. This module relies on ~polybar-another-battery~ ([[https://github.com/drdeimos/polybar_another_battery][link]]) and its generated binary ~polybar-ab~ which should be in the ~$PATH~.
The first line of the module declaration lets the user name the module however they want. In this case, the name is ~custom-battery~.
#+BEGIN_SRC conf-windows
[module/custom-battery]
#+END_SRC
Since it is not a core module, we have to declare it as a custom script so polybar knows what to do with it.
#+BEGIN_SRC conf-windows
type = custom/script
#+END_SRC
We now can specify the script execution, and whether or not the script will be continuously outputting something. In our case, the answer to this last question is yes.
#+BEGIN_SRC conf-windows
exec = polybar-ab -polybar -thr 10
tail = true
#+END_SRC
The ~-thr 10~ specifies the threshold for polybar-ab at which it should warn the user about the battery level of the computer.
Of course, users on desktop computers won’t need this module which is aimed at laptop users. Feel free to remove it if you do not need it.
This module allows to display information about our filesystem, including (and this is what I use this module for) displaying the used space and remaining space on different mount points. This module is an internal module to polybar, so let’s declare it as such:
#+BEGIN_SRC conf-windows
[module/filesystem]
type = internal/fs
#+END_SRC
We can specify how often the filesystem is to be checked with the variable ~interval~. I prefer it not to check it too often in order to not ping too often my drives, but I want it to be often enough so it is somewhat responsive. This is why I settled on a 20 seconds interval.
#+BEGIN_SRC conf-windows
interval = 20
#+END_SRC
We now have to indicate where our different filesystems are mounted. In the case of my main computer /Marpa/, I have two partitions, the root partition and the home partition. But on my travel laptop, I only have the root partition, hence the usage of the below Elisp code that determines based on the computer it is running whether or not the second mount point to my home partition should be included.
#+NAME: include-home-partition
#+BEGIN_SRC emacs-lisp :tangle no :exports code
(if (string= system-name "Marpa")
"mount-1 = /home")
#+END_SRC
#+BEGIN_SRC conf-windows
mount-0 = /
<<include-home-partition()>>
#+END_SRC
Now we can set the format of our module. There are two mains formats, one for mounted and one for unmounted mountpoints. For both, we’ll simply use their label.
#+BEGIN_SRC conf-windows
format-mounted = <label-mounted>
format-unmounted = <label-unmounted>
#+END_SRC
When it comes to the mounted partition, we want to display the name of the mountpoint and how used it is, both in terms of gigabytes and percentage.
If the volume is unmounted (which should be worrying considering the mountpoints chosen), then we’ll simply have a message telling us about that, and the foreground color will use the alternative foreground color described earlier.
This module is used in order to display the level of brightness of a screen. It is not used by itself, but rather by other modules, such as [[#Modules-Hardware-ACPI_backlight-9eaeaa79][ACPI backlight]]. First of all, this module is an internal module for xbacklight. It will also display the brightness percentage, prefixed by a sun emoji. Lastly, it will be underlined by a green line.
This module indicates the backlight level of a screen thanks to the ACPI Linux module. There isn’t much to tell about the module itself other than it inherits the module described above, [[#Modules-Hardware-Xbacklight-2901c504][xbacklight]]. It also sets which driver should be used, in this case the ~intel_backlight~ driver.
This module indicates how much of the CPU is being used. As shown below, I made it so we can see the load on each core. The first thing to do is to declare the module as an internal module dedicated to the CPU.
#+BEGIN_SRC conf-windows
[module/cpu]
type = internal/cpu
#+END_SRC
Now, we can set the refresh rate in seconds of the module. I like it at two seconds:
#+BEGIN_SRC conf-windows
interval = 2
#+END_SRC
Now, let’s declare what will be displayed. The format will be a computer emoji followed by ramp characters.
Similarly to the CPU module, it is possible for Polybar to display the RAM load of the computer. As above, let’s declare this module as an internal module to Polybar:
#+BEGIN_SRC conf-windows
[module/memory]
type = internal/memory
#+END_SRC
As the CPU module still, the refresh rate will be of two seconds.
#+BEGIN_SRC conf-windows
interval = 2
#+END_SRC
Its format will be the percentage of used RAM, prefixed by a disk emoji.
It is possible for Polybar to display the name of the current WiFi network the computer is connected to. For that, we first need to declare the Wlan module as an internal module of Polybar.
#+BEGIN_SRC conf-windows
[module/wlan]
type = internal/network
#+END_SRC
Now, we should set the name of the interface. As this depends on the hardware I am using, I am going to rely on the machine’s hostname and on some Elisp code to get this setting right.
#+NAME: name-wlan-interface
#+BEGIN_SRC emacs-lisp :exports code :tangle no
(cond ((string= system-name "Marpa") "wlp8s0")
((string= system-name "gampo") "wlp3s0"))
#+END_SRC
#+BEGIN_SRC conf-windows
interface = <<name-wlan-interface()>>
#+END_SRC
The name of the current WiFi network will be refreshed every three seconds.
#+BEGIN_SRC conf-windows
interval = 3.0
#+END_SRC
The format of the module when connected to a network will the the display of the antenna emoji, followed by the name of the network. When disconnected, the module will simply be empty.
Just like any other module, the ethernet module has to be declared as an internal module.
#+BEGIN_SRC conf-windows
[module/eth]
type = internal/network
#+END_SRC
And just like the Wlan module, it requires an interface which can vary depending on the machine I am using, hence this piece of Elisp:
#+NAME: name-eth-interface
#+BEGIN_SRC emacs-lisp :exports code :tangle no
(cond ((string= system-name "Marpa") "enp9s0")
((string= system-name "gampo") "enp0s25"))
#+END_SRC
#+BEGIN_SRC conf-windows
interface = <<name-eth-interface()>>
#+END_SRC
The format of this module will be the local address of the computer on the network, and it will be prefixed by a desktop computer emoji. Meanwhile, when disconnected, the module won’t be visible.
The temperature module checks the temperature of the CPU, and warns the user above a certain threshold of heat, in my case if my CPU is above 60°C.
#+BEGIN_SRC conf-windows
[module/temperature]
type = internal/temperature
thermal-zone = 0
warn-temperature = 60
#+END_SRC
The format of the module is the thermometer emoji followed by the temperature of the CPU. If the CPU becomes too hot, the text will change color for the secondary foreground color.
This module’s aim is to simply provide the name of the currently focused window given by Xorg. This module is an internal module to polybar, that is to say it is built-in, and is of the type ~xwindow~. So, let’s declare the module accordingly, including the piece of common code declared at the beginning of the chapter:
#+BEGIN_SRC conf-windows
[module/xwindow]
type = internal/xwindow
<<mod-prefix-col>>
#+END_SRC
Now we can take care of the label, which is the actual text that will be displayed. In our case, we want the label to be the title of the current X window, hence the value of ~label~, and we don’t want it to be too long, though I’m not sure I’ve often seen window titles longer than 70 characters.
Now comes the module for i3 interaction. Thanks to this module, it is possible to show which workspaces are active and focused, and it is possible to change workspaces by clicking on the ones displayed in the bar. First, let’s declare it; it is an internal module by the way.
#+BEGIN_SRC conf-windows
[module/i3]
type = internal/i3
#+END_SRC
Now, let’s display only the workspaces that are on the current output. This means if a workspace is either inactive or on another screen or output, it won’t be displayed.
#+BEGIN_SRC conf-windows
pin-workspaces = true
#+END_SRC
We also want our workspaces to be sorted by number rather than by output.
#+BEGIN_SRC conf-windows
index-sort = true
#+END_SRC
I don’t want to be able to scroll through the workspaces when my mouse is hovering the module: when it happens, most of the time it was done accidentally. So let’s deactivate that. However, I sometimes like to click on them to switch from one another, so we’ll keep that activated.
#+BEGIN_SRC conf-windows
enable-scroll = false
wrapping-scroll = false
reverse-scroll = false
enable-click = true
#+END_SRC
This parameters splits the workspaces’ name on ~:~. Let’s deactivate that.
#+BEGIN_SRC conf-windows
strip-wsnumbers = false
#+END_SRC
An on the topic of workspaces’ name, ~fuzzy-match~ allows the user to use fuzzy search for workspaces’ name when we will be applying custom names below. Not really useful since I only use the default workspaces’ name, but it’s good to have it enabled by default.
#+BEGIN_SRC conf-windows
fuzzy-match = true
#+END_SRC
The label format is described first by its label, but also by one of its three possible modes: focused, visible or unfocused. These will be discussed later, but for now let’s simply set our format.
#+begin_src conf-windows
format = <label-state> <label-mode>
#+end_src
We also wand to set the label mode to be whichever mode the workspace described by polybar is in. This label will also have a padding of 2 pixels, and the text will be written in white.
Now, let’s name our workspaces. We can give them whatever name we want them to have, but I just like the aesthetics of Japanese characters, so let’s go with the kanji equivalent of the number of the workspaces.
#+NAME: ws-names
| workspace number | name |
|------------------+------|
| 1 | 一 |
| 2 | 二 |
| 3 | 三 |
| 4 | 四 |
| 5 | 五 |
| 6 | 六 |
| 7 | 七 |
| 8 | 八 |
| 9 | 九 |
| 0 | 十 |
Here are the corresponding configuration lines:
#+BEGIN_SRC conf-windows
<<font-ws-config(text="ws",table=ws-names)>>
#+END_SRC
In case we create a workspace which isn’t named from ~0~ to ~9~, I want it to appear as is.
Now we can define the label itself. First, we will need to define the label when the workspace is focused. We’ll simply take the alternative background for the focused label, and the underline will be defined from Xrdb’s 8th color, with yellow as the fallback color. It will also have a two pixels padding. The text itself will be the dynamic icons declared above.
The ~visible~ label is related to the ~focused~ labels since it is describing workspaces that can be seen, but are not currently focused, i.e. a workspace that appears on another screen than the one currently used so it is visible, but it isn’t focused. The difference with the ~unfocused~ workspaces is that the latter are neither focused nor visible. As you can see, we are simply using all of the declarations from above for the focused labels so we can ensure they appear the same way the focused labels do.
When it comes to the unfocused label, there won’t be any custom background or underline, so we’ll just copy the two remaining lines from the focused labels for unfocused labels.
Lastly, we get our urgent workspaces: workspaces in which most of the time it’s just a popup that appeared or a software that finally launched itself while working on something else on another workspace. To make it a bit more unique, let’s declare its background as being the color 0 from xrdb, with some dark red as the fallback color. And as the other labels, the text will be the icon and it will have a two pixels padding.
Mpd is a music server for GNU/Linux systems that interfaces will several front-ends, including ncmpcpp (the main one I use), ncmpcpp and mpc. It also interfaces with polybar thanks to some built in commands.
First, let’s declare our module as an internal module.
#+BEGIN_SRC conf-windows
[module/mpd]
type = internal/mpd
#+END_SRC
The next thing we want to do is set the label for the module: we will display both the title and the name of the artist of the song playing. The maximum length will be 70 characters.
#+BEGIN_SRC conf-windows
label-song = %title% - %artist%
label-song-maxlen = 70
label-song-ellipsis = true
#+END_SRC
While Mpd is online, the format of the module should be the control icons and then the song label.
