SFWBAR()

NAME
SFWBar - S* Floating Window taskBar

test :Copyright: GPLv3+ :Manual section: 1

SYNOPSIS
sfwbar [options]

DESCRIPTION

SFWBar is a taskbar for wayland compositors. Originally written for Sway, it should work with any compositor supporting layer-shell protocol. SFWBar assists in handling of floating windows on a wayland desktop. It provides a taskbar, a pager, a task switcher, a system tray, a floating window placement engine, a simple widget set for display data extracted from various system files. SFWBar can work with any wayland compositor supporting layer shell protocol. Taskbar and switcher require either sway or wlr-foreign-toplevel protocol support. Placer and pager require sway.

OPTIONS

SFWBar executable can be invoked with the following options:

-f | --config
    Specify a filename of a configuration file

-c | --css
    Specify a filename of a css file

-s | --socket
    Specify a location of sway ipc socket

-m | --monitor
    Specify a monitor to display the bar on ("-m list" to list available monitors)

-b | --bar_id
    Specify a sway bar_id on which sfwbar will listen for status changes

CONFIGURATION

SFWBar reads configuration from a config file (sfwbar.config by default). The program checks users XDG config directory (usually ~/.config/sfwbar/) for this file, followed by system xdg data directories. Additionally, user can specify a location and a name of the config file using -f command line option.

Appearance of the program can be specified using CSS properties, these are sourced either from the css section of the main configuration file or from a file with a .css extension with the same base name as the config file located in the same directory as the config file. The name of the css file can be also specified using -c option.

Sfwbar can be restarted and configuration reloaded by sending a SIGHUP signal to the sfwbar process (i.e. killall -SIGHUP sfwbar).

The config file consists of the following top level sections:

  Placer

Placer section enables intelligent placement of new floating windows. If enabled the program will first attempt to place the window in a location, where it won't overlap with other windows. If such location doesn't exist, the window will be placed in a cascading pattern from top-left to bottom-right. The Placer declaration accepts parameters "xstep" and "ystep" that specify the steps in the window cascade. These are specified in percentage of the desktop dimensions. The cascade placement will start at a location specified by "xorigin" "yorigin" parameters. I.e.:

    placer {
      xorigin = 5
      yorigin = 5
      xstep = 5
      ystep = 5
      children = false
    }

"children" parameter specifies if new windows opened by a program with other windows already opened should be placed. These are usually dialog windows and SFWBar won't place them by default. If the placer section is not present in the file, SFWBar will let the compositor determine the locations for new windows.

  Task Switcher

Task switcher implements a keyboard shortcut to cycle focus across windows (i.e. Alt-Tab). The action is triggered upon receiving a change in a bar hidden_state property or signal SIGUSR1. This can be configured in Sway, via one of the following bindings:

    bindsym Alt-Tab bar hidden_state toggle
    or
    bindsym Alt-Tab exec killall -SIGUSR1 sfwbar

(for non-sway compositors, use SIGUSR1 trigger)

NixOS + Hyprland (probably other non-sway compositors) use:

    bind = ALT, Tab, exec, killall -SIGUSR1 .sfwbar-wrapped

Task switcher is configured in the "switcher" section of the configuration file. The following parameters are accepted:

interval
    an timeout after the last task switch event after which the selected window is activated

labels [true|false]
    display window titles in the task list

icons [true|false]
    display window icons in the task list

cols
    a number of columns in the task list

css css code applicable to the switcher grid. This property can only be set to a static string, not an expression. You can specify more detailed css code in the main CSS file. Using style name #switcher for the task switcher window and the main grid and names #switcher_normal and #switcher_active for inactive and active window representations respectively.

  Layout

Defines the layout of the taskbar. The layout holds a set of widgets. Widgets can be nested in case of a grid widget, which acts as a container.

The following widget types are supported:

taskbar
    a special widget displaying a list of all floating windows. (requires a compositor supporting wlr-foreign-toplevel protocol or i3 ipc)

pager
    a special widget displaying a list of all workspaces. (requires a compositor supporting wlr-foreign-toplevel protocol or i3 ipc)

tray
    a special widget displaying a list of tray icons received via status notifier item interface

grid
    a layout grid capable of containing other widgets. You can use these to further subdivide each cell of the main grid and arrange items within it.

label
    a label displaying text sourced from an expression. Labels accept pango markup to further theme text within them.

scale
    a progress bar with a progress value specified by an expression

chart
    a chart plotting the value of the expression over time

image
    display an icon or an image from a file. The name of an icon or a file is specified by an expression and can change dynamically.

button
    add a clickable button with an icon/image.

    Each widget is placed within the parent grid. By default, widgets are placed next to the previous widget along the "direction" of the grid (left to right by default). You can specify widget's positions within a grid by using a property "loc(x,y[,w,h])" with the first two parameters specifying the location of the widget within the parent grid and the last two parameters specifying the widget dimensions in grid cells:

        layout "id" {
          label {
          style = "mystyle"
          value = SwapUsed / SwapTotal + "%"
          loc(2,1,1,1)
          }
        }

    The optional "id" string of the layout, specifies the bar to populate and can control positioning of the grid within a bar using syntax of "name:position", valid positions are start, center and end. This allows placement of some widgets in the center of the bar. In case of a single bar, the name of a bar can be omitted, i.e. ":center". External widgets can be included in layout using the following syntax:

        layout {
          include("MyWidget.widget")
        }

    The above will include all scanner variables data and widget sub-layout from file MyWidget.widget

    Grid widgets can contain other widgets, these are declared within the grid definition i.e.

        grid {
          css = "* { border: none }"
          label "id" {
            ...
          }
        }

    Widgets can optionally have unique id's assigned to them in order to allow manipulating them in the future.

    All widgets can have the following properties:

value
    an expression specifying the value to display. This can be a static value (i.e. "string" or 1) or an expression (i.e. "Value is:" + $MyString or 2 * MyNumber.val). See expressions section for more detail. For Label widgets value tells text to display. For Scale widgets it specifies a fraction to display. For Chart widgets it specifies a fraction of the next datapoint. For Image widgets and buttons it provides an icon or an image file name.

style
    a style name for the widget. Styles can be used in CSS to theme widgets. Multiple widgets can have the same style. A style name can be used in css using gtk+ named widget convention, i.e. label#mystyle. Style property can be set to an expression to change styles in response to changes in system parameters.

tooltip
    sets a tooltip for a widget. A tooltip can be a static value or an expression. In case of the latter, the tooltip will be dynamically updated every time it pops up.

interval
    widget update frequency in milliseconds..

trigger
    trigger on which event updates. Triggers are emitted by Client sources a widget should not have both an interval and a trigger specified. (if both are specified, interval is ignored and trigger is used).

css additional css properties for the widget. These properties will only apply to the widget in question. You can have multiple instances of the css property in a single widget definition and they all will be applied in the order of their occurence. css property value can only be a static string, not an expression.

action
    an action to execute upon interaction with a widget. Actions can be attached to any widget. Multiple actions can be attached to various pointer events. The notation is action[<event>] = <action>. Event values are 1,2,3 or LeftClick, MiddleClick or RightClick respectively. For mouse scroll events, use values 4,5,6,7,8 or ScrollUp, ScrollDown, ScrollLeft, ScrollRight and Drag respectively. If no index is specified the action is attached to a left mouse button click. Additionallly, modifiers can be specified using the notation of [Modifier+]Index. I.e. action[Ctrl+LeftClick]. The following modifiers supported: Shift, Ctrl, Mod1, Mod2, Mod3, Mod4, Mod5, Super, Hyper, and Meta. Multiple modifiers can be added, i.e. action[Ctrl+Shift+ScrollUp]. action[0] will be executed on startup. You can use this action to set initial configuration for a widget. See Actions section for more details on how actions are specified.

    Taskbar widget may contain the following options

labels [true|false]
    an indicator whether to display an application title within the taskbar

icons [true|false]
    an indicator whether to display application icons within the taskbar

filter_output [true|false]
    This property is deprecated, please use filter instead. specifies whether taskbar should only list windows present on the same output as the taskbar

filter [output|workspace]
    Specifies whether taskbar should only list windows present on the same output or workspace as the taskbar itself.

title_width
    set maximum width of an application title in characters

sort [true|false]
    setting of whether taskbar items should be sorted. If the items are not sorted, user can sort them manually via drag-and-drop mechanism. Items are sorted by default, set this to false to enable drag-and-drop.

rows
    a number of rows in a taskbar.

cols
    a number of columns in a taskbar. If both rows and cols are specified, rows will be used. If neither is specified, the default is rows=1

group [popup|pager|false]
    if set to true, the taskbar items will be grouped. Supported grouppings are: popup and pager. In a popup grouping windows are grouped by app_id, the main taskbar will contain one item per app_id with an icon and a label set to app_id. On over, it will popup a "group taskbar" containing items for individual windows. In a pager grouping mode, the taskbar is partitioned into workspaces and each workspace contains windows belonging to it. Dragging windows from one workspace to another moves it to a destination workspace. (currently this is only supported with sway and hyprland compositors, support for other compositors requires adoption of new wayland protocols). You can specify taskbar parameters for the group taskbars using group prefix, i.e. group cols = 1. The properties supported for groups are cols, rows, style, css, title_width, labels, icons.

    Layout objects may have the following options

sensor <timeout>
    Specify whether the bar should be hidden once the pointer leaves the bar window (autohide). Once hidden, the bar will popup again if the pointer touches the sensor located along the screen edge along which the bar is placed. A numeric value specifies the bar pop-down delay in milliseconds. If the timeout is zero, the bar will always be visible.

size = <string>
    set size of the bar (width for top or bottom bar, height for left or right bar). The argument is a string. I.e. "800" for 800 pixels or "50%" for 50% of screen size

monitor = <string>
    assign bar to a given monitor. The monitor name can be prefixed by "static:", i.e. "static:eDP-1". if this is set and the specified monitor doesn't exist or gets disconnected, the bar will not jump to another montior, but will be hidden and won't reappear until the monitor is reconnected.

mirror = <string>
    mirror the bar to monitors matching any of the specified patterns. The string parameter specifies a string list of patters to match the monitors against, i.e. "eDP-*", "HDMI-1" will mirror to any monitor with name starting with "eDP-" or monitor named "HDMI-1". Patterns starting with '!' will block the bar from being mirrored to a matching monitor. The patterns are specified in glob style '*' and '?' are used as wildcards. The simplest use is mirror = "*", which will mirror the bar across all monitors.

layer = <string>
    move bar to a specified layer (supported parameters are "top", "bottom", "background" and "overlay".

margin = <string>
    set margin around the bar to the number of pixels specified by string.

exclusive_zone <string>
    specify exclusive zone policy for the bar window. Acceptable values are "auto", "-1", "0" or positive integers. These have meanings in line with exclusive zone setting in the layer shell protocol. Default value is "auto"

sway_bar_id <string>
    specify bar ID to listen on for mode and hidden_state signals. If no bar ID is specified, SfwBar will listen to signals on all IDs

    Pager widget may contain the following options

preview [true|false]
    specifies whether workspace previews are displayed on mouse hover over pager buttons

sort [true|false]
    setting of whether pager items should be sorted. If the items are not sorted, user can sort them manually via drag-and-drop mechanism. Items are sorted by default, set this to false to enable drag-and-drop.

pins
    a list of "pinned" workspaces. These will show up in the pager even if the workspace is empty.

rows
    a number of rows in a pager.

cols
    a number of columns in a pager. If both rows and cols are specified, rows will be used. If neither is specified, the default is rows=1

    tray widget may contain the following options

rows
    a number of rows in a pager.

cols
    a number of columns in a pager. If both rows and cols are specified, rows will be used. If neither is specified, the default is rows=1

sort [true|false]
    setting of whether tray items should be sorted. If the items are not sorted, user can sort them manually via drag-and-drop mechanism. Items are sorted by default, set this to false to enable drag-and-drop.

    popup window may contain the following options

AutoClose [true|false]
    specify whether the popup window should close if user clicks anywhere outside of the window.

  PopUp

Popup windows can be defined the same way as layouts. The only difference is that popup's are not part of a bar and will not be displayed by default. Instead they are displayed when a PopUp action is invoked on a widget. i.e.:

    PopUp "MyPopup" {
      label { value = "test" }
    }
    Layout {
      label {
        value = "click me"
        action = PopUp "MyPopup"
      }
    }

The PopUp action toggles visibility of the popup window. I.e. the first time it's invoked, the window will pop up and on the second invocation it will pop down. As a result it should be safe to bind the PopUp to multiple widgets.

  Menus

User defined menus can be attached to any widget (see action widget property). Menus are defined using a Menu section in the config file. The example syntax is as following:

    menuclear("menu_name")
    menu ("menu_name") {
      item("item1", Exec "command")
      separator
      submenu("sub","mysubmenu") {
        item("item2", SwayCmd "focus next")
      }
    }

Command MenuClear deletes any existing items from a menu. Each menu has a name used to link the menu to the widget action and a list of menu items. If a menu with the same name is defined more than once, the items from subsequent declarations will be appended to the original menu. If you want to re-define the menu, use MenuClear action to clear the original menu.

The following menu items are supported:

item
    an actionable menu item. This item has three parameters, the first one is a label, the second is an action to execute when the item is activated, the third is an option id you can use to delete the item later if needed. See Actions section for more details on supported actions.

separator
    a menu separator. This item has no parameters

submenu
    attach a submenu. The first parameter parameter is a label to display in the parent menu, the second optional parameter is a menu name, if a menu name is assigned, the third optional parameter is an id you can use later to delete the submenu using MenuItemClear action. Further items can be added to a submenu as to any other menu.

  Triggers

Triggers are emitted in response to various events, such as compositor state changes, real time signals or notifications from modules. Some triggers can be defined as part of the configuration (i.e. SocketClient or ExecClient scanner sources), others are built in, or defined in modules.

Built-in triggers are:
SIGRTMIN+X | RT signal SIGRTMIN+X has been received (X is a number)
sway | Data has been received on SwayClient scanner source
mpd | Data has been received on MpdClient scanner source
<output>-connected | an output has been connected (i.e. eDP-1-connected)
<output>-disconnected | an output has been disconnected

  Actions

Actions can be attached to click and scroll events for any widget or to items within a menu. Actions can be conditional on a state of a window or a widget they refer to and some actions may require a parameter. Conditions are specified in square brackets prior to the action i.e. [Minimized] and can be inverted using ! or joined using | i.e. [!Minimized | Focused]. All conditions on the list must be satisfied. Supported conditions are: Minimized, Maximized, Focused, FullScreen and UserState

Actions can be activated upon receipt of a trigger from one of the client type sources, using TriggerAction top-level keyword. I.e.

    TriggerAction "mytrigger", Exec "MyCommand"

Parameters are specified as strings immediately following the relevant action. I.e. Menu "WindowOps". Some actions apply to a window, if the action is attached to taskbar button, the action will be applied to a window referenced by the button, otherwise, it will apply to the currently focused window. The following action types are supported:

Config <string>
    Process a snippet of configuration file. This action permits changing the bar configuration on the fly

Exec <string>
    execute a shell command

Function [<addr>,]<string>
    Execute a function. Accepts an optional address, to invoke a function on a specific widget.

Menu <string>
    open a menu with a given name

MenuClear <string>
    delete a menu with a given name (This is useful if you want to generate menus dynamically via PipeRead and would like to delete a previously generated menu)

MenuItemClear <string>
    delete a menu item with an id corresponding to the string. The menu item must be declared with an id if you want to use this action on it.

PipeRead <string>
    Process a snippet of configuration sourced from an output of a shell command

SwayCmd <string>
    send a command over Sway IPC

SwayWinCmd <string>
    send a command over Sway IPC applicable to a current window

MpdCmd <string>
    send a command to Music Player Daemon

ClientSend <string>, <string>
    send a string to a client. The string will be written to client's standard input for execClient clients or written into a socket for socketClient's. The first parameter is the client id, the second is the string to send.

SwitcherEvent <string>
    trigger a switcher event, this action will bring up the switcher window and cycle the focus either forward or back based on the argument. The string argument can be either "foward" or "back". If the argument is omitted, the focus will cycle forward.

MapIcon <app_id>, <icon>
    use icon <icon> for applications with app id <app_id>.

SetMonitor [<bar_name>,]<string>
    move bar to a given monitor. Bar_name string specifies a bar to move. monitor name can be prefixed by "static:", i.e. "static:eDP-1", if this is set and the specified monitor doesn't exist or gets disconnected, the bar will not jump to another montior, but will be hidden and won't reappear until the monitor is reconnected. ** This action is deprecated, please use property monitor instead **

SetMirror [<bar_name>,]<string>
    mirror the bar to monitors matching any of the specified patterns. If bar_name is specified, mirror instruction would be applied to specific bar, otherwise it will be applied to all bars. The string parameter specifies a colon delimited list of patters to match the monitors against, i.e. "eDP-:HDMI-1" will mirror to any monitor with name starting with "eDP-" or monitor named "HDMI-1". The patterns are specified in glob style '' and '?' are used as wildcards. A simplest use is SetMirror "*" will mirror all bars across all monitors. ** This action is deprecated, please use property mirror instead **

SetLayer [<bar_name>,]<string>
    move bar to a specified layer (supported parameters are "top", "bottom", "background" and "overlay". ** This action is deprecated, please use property layer instead **

SetBarSize [<bar_name>,]<string>
    set size of the bar (width for top or bottom bar, height for left or right bar). The argument is a string. I.e. "800" for 800 pixels or "50%" for 50% of screen size ** This action is deprecated, please use property size instead **

SetBarMargin [<bar_name>,]<string>
    set margin around the bar to the number of pixels specified by string. ** This action is deprecated, please use property margin instead **

SetBarSensor [<bar_name>],<string>
    Specify whether the bar should be hidden once the pointer leaves the bar window. Once hidden, the bar will popup again if the pointer touches the sensor located along the screen edge along which the bar is placed. String specifies the bar pop-down delay in milliseconds. ** This action is deprecated, please use property sensor instead **

SetBarID <string>
    specify bar ID to listen on for mode and hidden_state signals. If no bar ID is specified, SfwBar will listen to signals on all IDs ** This action is deprecated, please use property sway_bar_id instead **

SetExclusiveZone [<bar_name>,]<string>
    specify exclusive zone policy for the bar window. Acceptable values are "auto", "-1", "0" or positive integers. These have meanings in line with exclusive zone setting in the layer shell protocol. Default value is "auto" ** This action is deprecated, please use property exclusive_zone instead **

SetValue [<widget>,]<string>
    set the value of the widget. This action applies to the widget from which the action chain has been invoked. I.e. a widget may popup a menu, which in turn will call a function, which executed SetValue, the SetValue will still ac upon the widget that popped up the menu.

SetStyle [<widget>,]<string>
    set style name for a widget

SetTooltip [<widget>,]<string>
    set tooltip text for a widget

UserState <string>
    Set boolean user state on a widget. Valid values are "On" or "Off".

Focus
    set window to focused

Close
    close a window

Minimize
    minimize a window (send to scratchpad in sway)

UnMinimize
    unset a minimized state for the window

Maximize
    maximize a window (set fullscreen in sway)

UnMaximize
    unset a maximized state for the window

  Functions

Functions are sequences of actions. They are used when multiple actions need to be execute on a single triggeer. A good example of this functionality is dynamically constructed menus generated by an external script:

    function("fancy_menu") {
      MenuClear "dynamic_menu"
      PipeRead "$HOME/bin/buildmenu.sh"
      Menu "dynamic_menu"
    }

The above example clears a menu, executes a script that builds a menu again and opens the resulting menu.

Function "SfwBarInit" executed on startup. You can use this function to set initial parameters for the bar, such as default monitor and layer.

  Scanner

SFWBar widgets display data obtained from various sources. These can be files or output of commands.

Each source section contains one or more variables that SFWBar will poll periodically and populate with the data parsed from the source. The sources and variables linked to them as configured in the section scanner

    scanner {
      File("/proc/swaps",NoGlob) {
        SwapTotal = RegEx("[\t ]([0-9]+)")
        SwapUsed = RegEx("[\t ][0-9]+[\t ]([0-9]+)")
      }
      Exec("getweather.sh") {
        WeatherTemp = Json(".forecast.today.degrees")
      }
      ExecClient("stdbuf -oL foo.sh BAR BAZ", "foo") {
        Foo_foo = Json(".foo")
        Foo_bar = Json(".bar")
      }
    }

Each declaration within the scanner section specifies a source. This can be one of the following:

File
    Read data from a file

Exec
    Read data from an output of a shell command

ExecClient
    Read data from an executable, this source will wait for any output from the standard output of the executable. Once available (i.e. the program flushes its output) the source will populate the variables and emit a trigger event. This source accepts two parameters, command to execute and an id. The id can be used to write to the standard input of the executable via ClientSend (provided that the executable takes standard input) and to identify a trigger emitted upon variable updates. USE RESPONSIBLY: If a trigger causes the client to receive new data (i.e. by triggering a ClientSend command that in turn triggers response from the source, you can end up with an infinite loop. (see alsa.widget and rfkill-wifi.widget as examples).

SocketClient
    Read data from a socket, this source will read a bust of data using it to populate the variables and emit a trigger event once done. This source accepts two parameters, a socket address and an id. The id is used to address the socket via ClientSend and to identify a trigger emitted upon variable updates. USE RESPONSIBLY: If a trigger causes the client to receive new data (i.e. by triggering a ClientSend command that in turn triggers response from the source, you can end up with an infinite loop.

MpdClient
    Read data from Music Player Daemon IPC (data is polled whenever MPD responds to an 'idle player' event). MpdClient emits trigger "mpd". (see mpd-int.widget as an example)

SwayClient
    Receive updates on Sway state, updates are the json objects sent by sway, wrapped into an object with a name of the event i.e. window: { sway window change object }. SwayClient emits trigger "sway". (see sway-lang.widget as an example).

    The file source also accepts further optional arguments specifying how scanner should handle the source, these can be:

NoGlob
    specifies that SFWBar shouldn't attempt to expand the pattern in the file name. If this flag is not specified, the file source will attempt to read from all files matching a filename pattern.

CheckTime
    indicates that the program should only update the variables from this file when file modification date/time changes.

    Variables are extracted from sources using parsers, currently the following parsers are supported:

Grab([Aggregator])
    specifies that the data is copied from the file verbatim

RegEx(Pattern[,Aggregator])
    extracts data using a regular expression parser, the variable is assigned data from the first capture buffer

Json(Path[,Aggregator])
    extracts data from a json structure. The path starts with a separator character, which is followed by a path with elements separated by the same character. The path can contain numbers to indicate array indices i.e. .data.node.1.string and key checks to filter arrays, i.e. .data.node.[key="blah"].value

    Optional aggregators specify how multiple occurrences of numeric data are treated. The following aggregators are supported:

First
    Variable should be set to the first occurrence of the pattern in the source

Last
    Variable should be set to the last occurrence of the pattern in the source

Sum Variable should be set to the sum of all occurrences of the pattern in the source

Product
    Variable should be set to the product of all occurrences of the pattern in the source

    For string variables, Sum and Product aggregators are treated as Last.

  Global Options

Theme <string>
    Override a Gtk theme to name specified.

IconTheme <string>
    Override a Gtk icon theme.

DisownMinimized <boolean>
    Disassociate windows from their workplaces when they are minimized. If this option is set, selecting a minimize window will unminimize it on the active workplace. If set to False (default), the window will be unminimzied to it's last workplace. This option only applies to Sway and Hyprland comositors

FilterTitle <regex>
    Any windows with titles matching a regular expression <regex> will not be shown on the taskbar or switcher.

FilterAppId <regex>
    Any windows with appids matching a regular expression <regex> will not be shown on the taskbar or switcher.

TriggerAction <trigger>, <action>
    execute an action when a trigger is emitted. Trigger is a string, an action is any valid action, as described in the Actions section.

  EXPRESSIONS

Values in widgets can contain basic arithmetic and string manipulation expressions. These allow transformation of data obtained by the scanner before it is displayed by the widgets.

The numeric operations are:
Operation | Description
+ | addition
- | subtraction
* | multiplication
/ | division
% | remainder of an integer division
> | greater than
>= | greater than or equal
< | less than
>= | less than or equal
 | equal
Val | convert a string into a number, the argument is a string or a string expression to convert.
If | conditional: If(condition,expr1,expr2)
Cached | get last value from a variable without updating it: Cached(identifier)
Ident | Check if an identifier exists either as a variable or a function

The string operations are:
Operation | Description
+ | concatenate strings i.e. "'String'+$Var".
Mid | extract substring i.e. Mid($Var,2,5)
Extract | extract a regex pattern i.e. Extract($Var,'FindThis: (GrabThat)')
Str | convert a number into a string, the first argument is a number (or a numeric expression), the second argument is decimal precision. If precision is omitted, the number is rounded to the nearest integer.
Pad | pad a string to be n characters long, the first parameter is a string to pad, the second is the desired number of characters, if the number is negative, the string is padded at the end, if positive, the string is padded at the front. The third optional string parameter specifies the character to pad the string with.
Upper | Convert a string to upper case
Lower | Convert a string to lower case
Escape | Sanitize text input for label widget.
Read | Read contents of a file into a string
Replace | Replace one substring with another within a string Replace (string, old, new)
Lookup | lookup a numeric value within a list of tuplets, the function call is Lookup(Value, Threshold1, String1, ..., DefaultString). The function checks value against a thresholds and returns a String associated with the highest threshold matched by the Value. If the Value is lower than all thresholds, DefaultString is returned. Thresholds in the function call must be in decreasing order.
Map | Match a string within a list of tuplets, the usage is: Map(Value, Match1,String`,...,DefaultString). The function will match Value against all Match strings and will return a corresponding String, if none of the Match strings match, the function will return DefaultString.
ReplaceAll | Perform multiple substring replacements in a string, ReplaceAll(string, old1, new1, ... )

In addition the following query functions are supported
Function | Description
Time | get current time as a string, the first optional argument specifies the format, the second argument specifies a timezone. Return a string
ElapsedStr | format a time interval specified in second into an elapsed time string, i.e. Just now or 5 minutes ago.
Disk | get disk utilization data. You need to specify a mount point as a first argument and data field as a second. The supported data fields are "total", "avail", "free", "%avail", "%free" or "%used". Returns a number.
ActiveWin | get the title of currently focused window. Returns a string.
GtkEvent | Get the location of an event that triggered the action. This function is only applicable in action command expressions where an action is called as a result of button click. The function returns location of the click within the widget. The value is returned as percentage of the widget width or height. Acceptable arguments are "X","Y" and "Dir". X and Y select an axis for which to return the event location, Dir returns the event location along the widget direction property.
BarDir | get direction property of the taskbar holding the current widget. Returns a string: "left", "right", "top", "bottom" or "unknown".
WidgetID | Obtain an ID of the current widget (i.e. a widget in respect to which the expression is being evaluated.
WindowInfo | Obtain information about a window. This function takes window property as a single input parameter. Valid properties are: appid, title, minimized, maximized, fullscreen, focused

Each numeric variable contains four values

.val
    current value of the variable

.pval
    previous value of the variable

.time
    time elapsed between observing .pval and .val

.age
    time elapsed since variable was last updated

.count
    a number of time the pattern has been matched during the last scan

    By default, the value of the variable is the value of .val. String variables are prefixed with $, i.e. $StringVar The following string operation are supported. For example:

        $MyString + Str((MyValue - MyValue.pval)/MyValue.time),2)

    User defined expression macros are supported via top-level define keyword. I.e.

        define MyExpr = VarA + VarB * VarC + Val($Complex)
        ...
        value = Str(MyExpr,2)

    The above will expand the expression into:

        value = Str(VarA + VarB * VarC + Val($Complex),2)

    Macro's don't have types, as they perform substitution before the expression is evaluated.

    Intermediate variables can be declared using a toplevel set keyword I.e.

        set MyExpr = VarA + VarB * VarC + Val($Complex
        ...
        value = Str(MyExpr,2)

    In the above example, value of the MyExpr variable will be calculated and the result will be used in computing the value expression. Intermediate variables have type and have all of the fields of a scan variable (i.e. val, pval, time etc). They can be used the same way as scan variables.

MISCELLANEOUS

If the icon is missing for a specific program in the taskbar or switcher, it is likely due to an missing icon or application not setting app_id correctly. You can check app_id's of running programs by running sfwbar -d -g app_id. if app_id is present, you need to add an icon with the appropriate name to your icon theme. If it's blank, you can try mapping it from the program's title (please note that the title may change during runtime, so matching it can be tricky). Mapping is supported via top-level MapAppId keyword. I.e.

    MapAppId app_id, pattern

where app_id is the desired app_id and pattern is a regular expression to match the title against.

If you are using an XWayland app, they usually do not have an app_id set. If an icon is not showing, you can add your icon to the following locations: 1. $HOME/.icons 2. One of the directories listed in $XDG_DATA_DIRS/icons 3. /usr/share/pixmaps 4. Location of the main config file currently in use 5. $XDG_CONFIG_HOME/sfwbar/

If an app_id is not set, and sway is being used, sfwbar will fallback to using the instance in the window-properties.

You can find the app_id that is being used with sfwbar by using the sfwbar -d -g app_id command, which will show a list of running applications if your compositor supports the wlr-foreign-toplevel protocol (i.e. labwc, wayfire, sway): ` 14:49:25.41 app_id: 'jetbrains-clion', title 'sfwbar – pager.c' `

Alternatively your desktop environment might have a command to display a list: - Sway: swaymsg -t get_tree - Hyperland: hyprctl -j clients

When using swaymsg -t get_tree, with CLion this will show the following:

    "window_properties": {
      "class": "jetbrains-clion",
      "instance": "jetbrains-clion",
      "title": "sfwbar – trayitem.c",
      "transient_for": null,
      "window_type": "normal"
    }

So we can put an icon called jetbrains-clion.svg (or other formats, see the [Arch wiki]( <https://wiki.archlinux.org/title/desktop_entries#Icons> )) for information about file formats.

CSS STYLE

SFWBar uses gtk+ widgets and can accept all css properties supported by gtk+. SFWBar widgets correspond to gtk+ widgets as following:
SFWBar widget | gtk+ widget | css class
label | GtkLabel | label
image | GtkImage | image
button | GtkButton | button
scale | GtkProgressBar | progressbar, trough, progress

Taskbar, Pager, Tray and Switcher use combinations of these widgets and can be themed using gtk+ nested css convention, i.e. grid#taskbar button { ... } (this example assumes you assigned style = taskbar to your taskbar widget).

In addition to standard gtk+ css properties SFWBar implements several additional properties. These are:
property | description
-GtkWidget-align | specify text alignment for a label, defined as a fraction. (i.e. 0 = left aligned, 1 = right aligned, 0.5 = centered)
-GtkWidget-ellipsize | specify whether a text in a label should be ellipsized if it's too long to fit in allocated space.
-GtkWidget-wrap | wrap a string if it's too long for it's container (you would usually want to pair it with -GtkWidget-max-width)
-GtkWidget-direction | specify a direction for a widget. For scale, it's a direction towards which scale grows. For a grid, it's a direction in which a new widget is position relative to the last placed widget. For a window it's an edge along which the bar is positioned. Possible values [top|bottom|left|right]
-GtkWidget-max-width | Limit maximum width of a widget (in pixels)
-GtkWidget-max-height | Limit maximum height of a widget (in pixels)
-GtkWidget-hexpand | specify if a widget should expand horizontally to occupy available space. [true|false]
-GtkWidget-vexpand | as above, for vertical expansion.
-GtkWidget-halign | Horizontally align widget within any free space allocated to it, values supported are: fill, start, end, center and baseline. The last vertically aligns widgets to align text within.
-GtkWidget-valign | Vertically align widget.
-GtkWidget-visible | Control visibility of a widget. If set to false, widget will be hidden.
-ScaleImage-color | Specify a color to repaint an image with. The image will be painted with this color using image's alpha channel as a mask. The color's own alpha value can be used to tint an image.
-ScaleImage-symbolic | Render an image as a symbolic icon. If set to true, the image will be re-colored to the gtk theme foreground color, preserving the image alpha channel. This property is ignored if -ScaleImage-color is specified.
-ScaleImage-shadow-radius | specify a radius for a drop shadow of an image widget. A drop shadow is rendered if a radius or one of the offsets is specified for an image. (an integer specifying a number of pixels).
-ScaleImage-shadow-x-offset | a horizontal offset of a drop shadow relative to an image. (an integer specifying a number of pixels).
-ScaleImage-shadow-y-offset | a vertical offset of a drop shadow relative to an image. (an integer specifying a number of pixels).
-ScaleImage-shadow-clip | a boolean specifying whether a shadow is clipped to a padding box. If false, the shadow may spill over a border and a margin of a widget. (default = true)
-ScaleImage-shadow-color | a color of a drop shadow.

Taskbar and pager buttons are assigned the following styles
style name | description
sfwbar | toplevel bar window
layout | top level layout grid
taskbar_item | taskbar button for a window (supports class .active)
takbar_popup | taskbar popup button (supports class .active)
taskbar_pager | taskbar pager grid (supports class .active)
pager_item | pager button for a workspace (supports classes .focused and .visible)
switcher_item | switcher window and top level grid (supports class .active)
tray | tray menus and menu items
tray_item | tray item icon (supports classes .passive and .attention)
menu_item | menu items (each contains an image and a label)

For example you can style top level grid using grid#layout { }.