feat: support for 'ironvar' dynamic variables

src/config/common.rs

@@ -1,11 +1,9 @@
-use crate::dynamic_string::DynamicString;
+use crate::dynamic_value::{dynamic_string, DynamicBool};
 use crate::script::{Script, ScriptInput};
-use crate::send;
 use gtk::gdk::ScrollDirection;
 use gtk::prelude::*;
 use gtk::{EventBox, Orientation, Revealer, RevealerTransitionType};
 use serde::Deserialize;
-use tokio::spawn;
 use tracing::trace;
 
 /// Common configuration options
@@ -15,7 +13,7 @@ pub struct CommonConfig {
     pub class: Option<String>,
     pub name: Option<String>,
 
-    pub show_if: Option<ScriptInput>,
+    pub show_if: Option<DynamicBool>,
     pub transition_type: Option<TransitionType>,
     pub transition_duration: Option<u32>,
 
@@ -114,7 +112,7 @@ impl CommonConfig {
 
         if let Some(tooltip) = self.tooltip {
             let container = container.clone();
-            DynamicString::new(&tooltip, move |string| {
+            dynamic_string(&tooltip, move |string| {
                 container.set_tooltip_text(Some(&string));
                 Continue(true)
             });
@@ -127,23 +125,13 @@ impl CommonConfig {
                 container.show_all();
             },
             |show_if| {
-                let script = Script::new_polling(show_if);
                 let container = container.clone();
-                let (tx, rx) = glib::MainContext::channel(glib::PRIORITY_DEFAULT);
-
-                spawn(async move {
-                    script
-                        .run(None, |_, success| {
-                            send!(tx, success);
-                        })
-                        .await;
-                });
 
                 {
                     let revealer = revealer.clone();
                     let container = container.clone();
 
-                    rx.attach(None, move |success| {
+                    show_if.subscribe(move |success| {
                         if success {
                             container.show_all();
                         }

src/config/mod.rs

@@ -100,6 +100,8 @@ pub struct Config {
     /// GTK icon theme to use.
     pub icon_theme: Option<String>,
 
+    pub ironvar_defaults: Option<HashMap<Box<str>, String>>,
+
     pub start: Option<Vec<ModuleConfig>>,
     pub center: Option<Vec<ModuleConfig>>,
     pub end: Option<Vec<ModuleConfig>>,

src/dynamic_string.rs

@@ -1,160 +0,0 @@
-use crate::script::{OutputStream, Script};
-use crate::{lock, send};
-use gtk::prelude::*;
-use std::sync::{Arc, Mutex};
-use tokio::spawn;
-
-/// A segment of a dynamic string,
-/// containing either a static string
-/// or a script.
-#[derive(Debug)]
-enum DynamicStringSegment {
-    Static(String),
-    Dynamic(Script),
-}
-
-/// A string with embedded scripts for dynamic content.
-pub struct DynamicString;
-
-impl DynamicString {
-    /// Creates a new dynamic string, based off the input template.
-    /// Runs `f` with the compiled string each time one of the scripts updates.
-    ///
-    /// # Example
-    ///
-    /// ```rs
-    /// DynamicString::new(&text, move |string| {
-    ///     label.set_markup(&string);
-    ///     Continue(true)
-    /// });
-    /// ```
-    pub fn new<F>(input: &str, f: F) -> Self
-    where
-        F: FnMut(String) -> Continue + 'static,
-    {
-        let segments = Self::parse_input(input);
-
-        let label_parts = Arc::new(Mutex::new(Vec::new()));
-        let (tx, rx) = glib::MainContext::channel(glib::PRIORITY_DEFAULT);
-
-        for (i, segment) in segments.into_iter().enumerate() {
-            match segment {
-                DynamicStringSegment::Static(str) => {
-                    lock!(label_parts).push(str);
-                }
-                DynamicStringSegment::Dynamic(script) => {
-                    let tx = tx.clone();
-                    let label_parts = label_parts.clone();
-
-                    // insert blank value to preserve segment order
-                    lock!(label_parts).push(String::new());
-
-                    spawn(async move {
-                        script
-                            .run(None, |out, _| {
-                                if let OutputStream::Stdout(out) = out {
-                                    let mut label_parts = lock!(label_parts);
-
-                                    let _: String = std::mem::replace(&mut label_parts[i], out);
-
-                                    let string = label_parts.join("");
-                                    send!(tx, string);
-                                }
-                            })
-                            .await;
-                    });
-                }
-            }
-        }
-
-        // initialize
-        {
-            let label_parts = lock!(label_parts).join("");
-            send!(tx, label_parts);
-        }
-
-        rx.attach(None, f);
-
-        Self
-    }
-
-    /// Parses the input string into static and dynamic segments
-    fn parse_input(input: &str) -> Vec<DynamicStringSegment> {
-        if !input.contains("{{") {
-            return vec![DynamicStringSegment::Static(input.to_string())];
-        }
-
-        let mut segments = vec![];
-
-        let mut chars = input.chars().collect::<Vec<_>>();
-        while !chars.is_empty() {
-            let char_pair = if chars.len() > 1 {
-                Some(&chars[..=1])
-            } else {
-                None
-            };
-
-            let (token, skip) = if let Some(['{', '{']) = char_pair {
-                const SKIP_BRACKETS: usize = 4; // two braces either side
-
-                let str = chars
-                    .windows(2)
-                    .skip(2)
-                    .take_while(|win| win != &['}', '}'])
-                    .map(|w| w[0])
-                    .collect::<String>();
-
-                let len = str.len();
-
-                (
-                    DynamicStringSegment::Dynamic(Script::from(str.as_str())),
-                    len + SKIP_BRACKETS,
-                )
-            } else {
-                let mut str = chars
-                    .windows(2)
-                    .take_while(|win| win != &['{', '{'])
-                    .map(|w| w[0])
-                    .collect::<String>();
-
-                // if segment is at end of string, last char gets missed above due to uneven window.
-                if chars.len() == str.len() + 1 {
-                    let remaining_char = *chars.get(str.len()).expect("Failed to find last char");
-                    str.push(remaining_char);
-                }
-
-                let len = str.len();
-
-                (DynamicStringSegment::Static(str), len)
-            };
-
-            // quick runtime check to make sure the parser is working as expected
-            assert_ne!(skip, 0);
-
-            segments.push(token);
-            chars.drain(..skip);
-        }
-
-        segments
-    }
-}
-
-#[cfg(test)]
-mod tests {
-    use super::*;
-
-    #[tokio::test]
-    async fn test() {
-        // TODO: see if we can run gtk tests in ci
-        if gtk::init().is_ok() {
-            let label = gtk::Label::new(None);
-            DynamicString::new(
-                "Uptime: {{1000:uptime -p | cut -d ' ' -f2-}}",
-                move |string| {
-                    label.set_label(&string);
-                    Continue(true)
-                },
-            );
-        }
-    }
-}

src/dynamic_value/dynamic_bool.rs

@@ -0,0 +1,78 @@
+#[cfg(feature = "ipc")]
+use crate::ironvar::get_variable_manager;
+use crate::script::Script;
+use crate::send;
+use cfg_if::cfg_if;
+use glib::Continue;
+use serde::Deserialize;
+use tokio::spawn;
+
+#[derive(Debug, Deserialize, Clone)]
+#[serde(untagged)]
+pub enum DynamicBool {
+    /// Either a script or variable, to be determined.
+    Unknown(String),
+    Script(Script),
+    #[cfg(feature = "ipc")]
+    Variable(Box<str>),
+}
+
+impl DynamicBool {
+    pub fn subscribe<F>(self, f: F)
+    where
+        F: FnMut(bool) -> Continue + 'static,
+    {
+        let value = match self {
+            Self::Unknown(input) => {
+                if input.starts_with('#') {
+                    cfg_if! {
+                        if #[cfg(feature = "ipc")] {
+                            Self::Variable(input.into())
+                        } else {
+                            Self::Unknown(input)
+                        }
+                    }
+                } else {
+                    let script = Script::from(input.as_str());
+                    Self::Script(script)
+                }
+            }
+            _ => self,
+        };
+
+        let (tx, rx) = glib::MainContext::channel(glib::PRIORITY_DEFAULT);
+
+        rx.attach(None, f);
+
+        spawn(async move {
+            match value {
+                DynamicBool::Script(script) => {
+                    script
+                        .run(None, |_, success| {
+                            send!(tx, success);
+                        })
+                        .await;
+                }
+                #[cfg(feature = "ipc")]
+                DynamicBool::Variable(variable) => {
+                    let variable_manager = get_variable_manager();
+
+                    let variable_name = variable[1..].into(); // remove hash
+                    let mut rx = crate::write_lock!(variable_manager).subscribe(variable_name);
+
+                    while let Ok(value) = rx.recv().await {
+                        let has_value = value.map(|s| is_truthy(&s)).unwrap_or_default();
+                        send!(tx, has_value);
+                    }
+                }
+                DynamicBool::Unknown(_) => unreachable!(),
+            }
+        });
+    }
+}
+
+/// Check if a string ironvar is 'truthy'
+#[cfg(feature = "ipc")]
+fn is_truthy(string: &str) -> bool {
+    !(string.is_empty() || string == "0" || string == "false")
+}

src/dynamic_value/dynamic_string.rs

@@ -0,0 +1,321 @@
+#[cfg(feature = "ipc")]
+use crate::ironvar::get_variable_manager;
+use crate::script::{OutputStream, Script};
+use crate::{lock, send};
+use gtk::prelude::*;
+use std::sync::{Arc, Mutex};
+use tokio::spawn;
+
+/// A segment of a dynamic string,
+/// containing either a static string
+/// or a script.
+#[derive(Debug)]
+enum DynamicStringSegment {
+    Static(String),
+    Script(Script),
+    #[cfg(feature = "ipc")]
+    Variable(Box<str>),
+}
+
+/// Creates a new dynamic string, based off the input template.
+/// Runs `f` with the compiled string each time one of the scripts or variables updates.
+///
+/// # Example
+///
+/// ```rs
+/// dynamic_string(&text, move |string| {
+///     label.set_markup(&string);
+///     Continue(true)
+/// });
+/// ```
+pub fn dynamic_string<F>(input: &str, f: F)
+where
+    F: FnMut(String) -> Continue + 'static,
+{
+    let tokens = parse_input(input);
+
+    let label_parts = Arc::new(Mutex::new(Vec::new()));
+    let (tx, rx) = glib::MainContext::channel(glib::PRIORITY_DEFAULT);
+
+    for (i, segment) in tokens.into_iter().enumerate() {
+        match segment {
+            DynamicStringSegment::Static(str) => {
+                lock!(label_parts).push(str);
+            }
+            DynamicStringSegment::Script(script) => {
+                let tx = tx.clone();
+                let label_parts = label_parts.clone();
+
+                // insert blank value to preserve segment order
+                lock!(label_parts).push(String::new());
+
+                spawn(async move {
+                    script
+                        .run(None, |out, _| {
+                            if let OutputStream::Stdout(out) = out {
+                                let mut label_parts = lock!(label_parts);
+
+                                let _: String = std::mem::replace(&mut label_parts[i], out);
+
+                                let string = label_parts.join("");
+                                send!(tx, string);
+                            }
+                        })
+                        .await;
+                });
+            }
+            #[cfg(feature = "ipc")]
+            DynamicStringSegment::Variable(name) => {
+                let tx = tx.clone();
+                let label_parts = label_parts.clone();
+
+                // insert blank value to preserve segment order
+                lock!(label_parts).push(String::new());
+
+                spawn(async move {
+                    let variable_manager = get_variable_manager();
+                    let mut rx = crate::write_lock!(variable_manager).subscribe(name);
+
+                    while let Ok(value) = rx.recv().await {
+                        if let Some(value) = value {
+                            let mut label_parts = lock!(label_parts);
+
+                            let _: String = std::mem::replace(&mut label_parts[i], value);
+
+                            let string = label_parts.join("");
+                            send!(tx, string);
+                        }
+                    }
+                });
+            }
+        }
+    }
+
+    rx.attach(None, f);
+
+    // initialize
+    {
+        let label_parts = lock!(label_parts).join("");
+        send!(tx, label_parts);
+    }
+}
+
+/// Parses the input string into static and dynamic segments
+fn parse_input(input: &str) -> Vec<DynamicStringSegment> {
+    // short-circuit parser if it's all static
+    if !input.contains("{{") && !input.contains('#') {
+        return vec![DynamicStringSegment::Static(input.to_string())];
+    }
+
+    let mut tokens = vec![];
+
+    let mut chars = input.chars().collect::<Vec<_>>();
+    while !chars.is_empty() {
+        let char_pair = if chars.len() > 1 {
+            Some(&chars[..=1])
+        } else {
+            None
+        };
+
+        let (token, skip) = match char_pair {
+            Some(['{', '{']) => parse_script(&chars),
+            Some(['#', '#']) => (DynamicStringSegment::Static("#".to_string()), 2),
+            #[cfg(feature = "ipc")]
+            Some(['#', _]) => parse_variable(&chars),
+            _ => parse_static(&chars),
+        };
+
+        // quick runtime check to make sure the parser is working as expected
+        assert_ne!(skip, 0);
+
+        tokens.push(token);
+        chars.drain(..skip);
+    }
+
+    tokens
+}
+
+fn parse_script(chars: &[char]) -> (DynamicStringSegment, usize) {
+    const SKIP_BRACKETS: usize = 4; // two braces either side
+
+    let str = chars
+        .windows(2)
+        .skip(2)
+        .take_while(|win| win != &['}', '}'])
+        .map(|w| w[0])
+        .collect::<String>();
+
+    let len = str.len() + SKIP_BRACKETS;
+    let script = Script::from(str.as_str());
+
+    (DynamicStringSegment::Script(script), len)
+}
+
+#[cfg(feature = "ipc")]
+fn parse_variable(chars: &[char]) -> (DynamicStringSegment, usize) {
+    const SKIP_HASH: usize = 1;
+
+    let str = chars
+        .iter()
+        .skip(1)
+        .take_while(|&c| !c.is_whitespace())
+        .collect::<String>();
+
+    let len = str.len() + SKIP_HASH;
+    let value = str.into();
+
+    (DynamicStringSegment::Variable(value), len)
+}
+
+fn parse_static(chars: &[char]) -> (DynamicStringSegment, usize) {
+    let mut str = chars
+        .windows(2)
+        .take_while(|&win| win != ['{', '{'] && win[0] != '#')
+        .map(|w| w[0])
+        .collect::<String>();
+
+    // if segment is at end of string, last char gets missed above due to uneven window.
+    if chars.len() == str.len() + 1 {
+        let remaining_char = *chars.get(str.len()).expect("Failed to find last char");
+        str.push(remaining_char);
+    }
+
+    let len = str.len();
+
+    (DynamicStringSegment::Static(str), len)
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_static() {
+        const INPUT: &str = "hello world";
+        let tokens = parse_input(INPUT);
+
+        assert_eq!(tokens.len(), 1);
+        assert!(matches!(&tokens[0], DynamicStringSegment::Static(value) if value == INPUT))
+    }
+
+    #[test]
+    fn test_static_odd_char_count() {
+        const INPUT: &str = "hello";
+        let tokens = parse_input(INPUT);
+
+        assert_eq!(tokens.len(), 1);
+        assert!(matches!(&tokens[0], DynamicStringSegment::Static(value) if value == INPUT))
+    }
+
+    #[test]
+    fn test_script() {
+        const INPUT: &str = "{{echo hello}}";
+        let tokens = parse_input(INPUT);
+
+        assert_eq!(tokens.len(), 1);
+        assert!(
+            matches!(&tokens[0], DynamicStringSegment::Script(script) if script.cmd == "echo hello")
+        );
+    }
+
+    #[test]
+    fn test_variable() {
+        const INPUT: &str = "#variable";
+        let tokens = parse_input(INPUT);
+
+        assert_eq!(tokens.len(), 1);
+        assert!(
+            matches!(&tokens[0], DynamicStringSegment::Variable(name) if name.to_string() == "variable")
+        );
+    }
+
+    #[test]
+    fn test_static_script() {
+        const INPUT: &str = "hello {{echo world}}";
+        let tokens = parse_input(INPUT);
+
+        assert_eq!(tokens.len(), 2);
+        assert!(matches!(&tokens[0], DynamicStringSegment::Static(str) if str == "hello "));
+        assert!(
+            matches!(&tokens[1], DynamicStringSegment::Script(script) if script.cmd == "echo world")
+        );
+    }
+
+    #[test]
+    fn test_static_variable() {
+        const INPUT: &str = "hello #subject";
+        let tokens = parse_input(INPUT);
+
+        assert_eq!(tokens.len(), 2);
+        assert!(matches!(&tokens[0], DynamicStringSegment::Static(str) if str == "hello "));
+        assert!(
+            matches!(&tokens[1], DynamicStringSegment::Variable(name) if name.to_string() == "subject")
+        );
+    }
+
+    #[test]
+    fn test_static_script_static() {
+        const INPUT: &str = "hello {{echo world}} foo";
+        let tokens = parse_input(INPUT);
+
+        assert_eq!(tokens.len(), 3);
+        assert!(matches!(&tokens[0], DynamicStringSegment::Static(str) if str == "hello "));
+        assert!(
+            matches!(&tokens[1], DynamicStringSegment::Script(script) if script.cmd == "echo world")
+        );
+        assert!(matches!(&tokens[2], DynamicStringSegment::Static(str) if str == " foo"));
+    }
+
+    #[test]
+    fn test_static_variable_static() {
+        const INPUT: &str = "hello #subject foo";
+        let tokens = parse_input(INPUT);
+
+        assert_eq!(tokens.len(), 3);
+        assert!(matches!(&tokens[0], DynamicStringSegment::Static(str) if str == "hello "));
+        assert!(
+            matches!(&tokens[1], DynamicStringSegment::Variable(name) if name.to_string() == "subject")
+        );
+        assert!(matches!(&tokens[2], DynamicStringSegment::Static(str) if str == " foo"));
+    }
+
+    #[test]
+    fn test_static_script_variable() {
+        const INPUT: &str = "hello {{echo world}} #foo";
+        let tokens = parse_input(INPUT);
+
+        assert_eq!(tokens.len(), 4);
+        assert!(matches!(&tokens[0], DynamicStringSegment::Static(str) if str == "hello "));
+        assert!(
+            matches!(&tokens[1], DynamicStringSegment::Script(script) if script.cmd == "echo world")
+        );
+        assert!(matches!(&tokens[2], DynamicStringSegment::Static(str) if str == " "));
+        assert!(
+            matches!(&tokens[3], DynamicStringSegment::Variable(name) if name.to_string() == "foo")
+        );
+    }
+
+    #[test]
+    fn test_escape_hash() {
+        const INPUT: &str = "number ###num";
+        let tokens = parse_input(INPUT);
+
+        assert_eq!(tokens.len(), 3);
+        assert!(matches!(&tokens[0], DynamicStringSegment::Static(str) if str == "number "));
+        assert!(matches!(&tokens[1], DynamicStringSegment::Static(str) if str == "#"));
+        assert!(
+            matches!(&tokens[2], DynamicStringSegment::Variable(name) if name.to_string() == "num")
+        );
+    }
+
+    #[test]
+    fn test_script_with_hash() {
+        const INPUT: &str = "{{echo #hello}}";
+        let tokens = parse_input(INPUT);
+
+        assert_eq!(tokens.len(), 1);
+        assert!(
+            matches!(&tokens[0], DynamicStringSegment::Script(script) if script.cmd == "echo #hello")
+        );
+    }
+}

src/dynamic_value/mod.rs

@@ -0,0 +1,7 @@
+#![doc = include_str!("../../docs/Dynamic values.md")]
+
+mod dynamic_bool;
+mod dynamic_string;
+
+pub use dynamic_bool::DynamicBool;
+pub use dynamic_string::dynamic_string;

src/ipc/commands.rs

@@ -10,5 +10,21 @@ pub enum Command {
 
     /// Open the GTK inspector
     Inspect,
-}
 
+    /// Set an `ironvar` value.
+    /// This creates it if it does not already exist, and updates it if it does.
+    /// Any references to this variable are automatically and immediately updated.
+    /// Keys and values can be any valid UTF-8 string.
+    Set {
+        /// Variable key. Can be any valid UTF-8 string.
+        key: Box<str>,
+        /// Variable value. Can be any valid UTF-8 string.
+        value: String,
+    },
+
+    /// Get the current value of an `ironvar`.
+    Get {
+        /// Variable key.
+        key: Box<str>,
+    },
+}

src/ipc/responses.rs

@@ -4,6 +4,7 @@ use serde::{Deserialize, Serialize};
 #[serde(tag = "type")]
 pub enum Response {
     Ok,
+    OkValue { value: String },
     Err { message: Option<String> },
 }
 

src/ipc/server.rs

@@ -106,6 +106,22 @@ impl Ipc {
             Command::Inspect => {
                 gtk::Window::set_interactive_debugging(true);
                 Response::Ok
+            },
+            Command::Set { key, value } => {
+                let variable_manager = get_variable_manager();
+                let mut variable_manager = write_lock!(variable_manager);
+                match variable_manager.set(key, value) {
+                    Ok(_) => Response::Ok,
+                    Err(err) => Response::error(&format!("{err}")),
+                }
+            }
+            Command::Get { key } => {
+                let variable_manager = get_variable_manager();
+                let value = read_lock!(variable_manager).get(&key);
+                match value {
+                    Some(value) => Response::OkValue { value },
+                    None => Response::error("Variable not found"),
+                }
             }
             Command::Ping => Response::Ok,
         }

src/ironvar.rs

@@ -0,0 +1,107 @@
+#![doc = include_str!("../docs/Ironvars.md")]
+
+use crate::{arc_rw, send};
+use color_eyre::{Report, Result};
+use lazy_static::lazy_static;
+use std::collections::HashMap;
+use std::sync::{Arc, RwLock};
+use tokio::sync::broadcast;
+
+lazy_static! {
+    static ref VARIABLE_MANAGER: Arc<RwLock<VariableManager>> = arc_rw!(VariableManager::new());
+}
+
+pub fn get_variable_manager() -> Arc<RwLock<VariableManager>> {
+    VARIABLE_MANAGER.clone()
+}
+
+/// Global singleton manager for `IronVar` variables.
+pub struct VariableManager {
+    variables: HashMap<Box<str>, IronVar>,
+}
+
+impl VariableManager {
+    pub fn new() -> Self {
+        Self {
+            variables: HashMap::new(),
+        }
+    }
+
+    /// Sets the value for a variable,
+    /// creating it if it does not exist.
+    pub fn set(&mut self, key: Box<str>, value: String) -> Result<()> {
+        if Self::key_is_valid(&key) {
+            if let Some(var) = self.variables.get_mut(&key) {
+                var.set(Some(value));
+            } else {
+                let var = IronVar::new(Some(value));
+                self.variables.insert(key, var);
+            }
+
+            Ok(())
+        } else {
+            Err(Report::msg("Invalid key"))
+        }
+    }
+
+    /// Gets the current value of an `ironvar`.
+    /// Prefer to use `subscribe` where possible.
+    pub fn get(&self, key: &str) -> Option<String> {
+        self.variables.get(key).and_then(IronVar::get)
+    }
+
+    /// Subscribes to an `ironvar`, creating it if it does not exist.
+    /// Any time the var is set, its value is sent on the channel.
+    pub fn subscribe(&mut self, key: Box<str>) -> broadcast::Receiver<Option<String>> {
+        self.variables
+            .entry(key)
+            .or_insert_with(|| IronVar::new(None))
+            .subscribe()
+    }
+
+    fn key_is_valid(key: &str) -> bool {
+        !key.is_empty()
+            && key
+                .chars()
+                .all(|char| char.is_alphanumeric() || char == '_' || char == '-')
+    }
+}
+
+/// Ironbar dynamic variable representation.
+/// Interact with them through the `VARIABLE_MANAGER` `VariableManager` singleton.
+#[derive(Debug)]
+struct IronVar {
+    value: Option<String>,
+    tx: broadcast::Sender<Option<String>>,
+    _rx: broadcast::Receiver<Option<String>>,
+}
+
+impl IronVar {
+    /// Creates a new variable.
+    fn new(value: Option<String>) -> Self {
+        let (tx, rx) = broadcast::channel(32);
+
+        Self { value, tx, _rx: rx }
+    }
+
+    /// Gets the current variable value.
+    /// Prefer to subscribe to changes where possible.
+    fn get(&self) -> Option<String> {
+        self.value.clone()
+    }
+
+    /// Sets the current variable value.
+    /// The change is broadcast to all receivers.
+    fn set(&mut self, value: Option<String>) {
+        self.value = value.clone();
+        send!(self.tx, value);
+    }
+
+    /// Subscribes to the variable.
+    /// The latest value is immediately sent to all receivers.
+    fn subscribe(&self) -> broadcast::Receiver<Option<String>> {
+        let rx = self.tx.subscribe();
+        send!(self.tx, self.value.clone());
+        rx
+    }
+}

src/macros.rs

@@ -1,7 +1,7 @@
 /// Sends a message on an asynchronous `Sender` using `send()`
 /// Panics if the message cannot be sent.
 ///
-/// Usage:
+/// # Usage:
 ///
 /// ```rs
 /// send_async!(tx, "my message");
@@ -16,7 +16,7 @@ macro_rules! send_async {
 /// Sends a message on an synchronous `Sender` using `send()`
 /// Panics if the message cannot be sent.
 ///
-/// Usage:
+/// # Usage:
 ///
 /// ```rs
 /// send!(tx, "my message");
@@ -31,7 +31,7 @@ macro_rules! send {
 /// Sends a message on an synchronous `Sender` using `try_send()`
 /// Panics if the message cannot be sent.
 ///
-/// Usage:
+/// # Usage:
 ///
 /// ```rs
 /// try_send!(tx, "my message");
@@ -46,7 +46,7 @@ macro_rules! try_send {
 /// Locks a `Mutex`.
 /// Panics if the `Mutex` cannot be locked.
 ///
-/// Usage:
+/// # Usage:
 ///
 /// ```rs
 /// let mut val = lock!(my_mutex);
@@ -62,7 +62,7 @@ macro_rules! lock {
 /// Gets a read lock on a `RwLock`.
 /// Panics if the `RwLock` cannot be locked.
 ///
-/// Usage:
+/// # Usage:
 ///
 /// ```rs
 /// let val = read_lock!(my_rwlock);
@@ -77,7 +77,7 @@ macro_rules! read_lock {
 /// Gets a write lock on a `RwLock`.
 /// Panics if the `RwLock` cannot be locked.
 ///
-/// Usage:
+/// # Usage:
 ///
 /// ```rs
 /// let mut val = write_lock!(my_rwlock);
@@ -88,3 +88,33 @@ macro_rules! write_lock {
         $rwlock.write().expect($crate::error::ERR_WRITE_LOCK)
     };
 }
+
+/// Wraps `val` in a new `Arc<Mutex<T>>`.
+///
+/// # Usage:
+///
+/// ```rs
+/// let val = arc_mut!(MyService::new());
+/// ```
+///
+#[macro_export]
+macro_rules! arc_mut {
+    ($val:expr) => {
+        std::sync::Arc::new(std::Sync::Mutex::new($val))
+    };
+}
+
+/// Wraps `val` in a new `Arc<RwLock<T>>`.
+///
+/// # Usage:
+///
+/// ```rs
+/// let val = arc_rw!(MyService::new());
+/// ```
+///
+#[macro_export]
+macro_rules! arc_rw {
+    ($val:expr) => {
+        std::sync::Arc::new(std::sync::RwLock::new($val))
+    };
+}

src/main.rs

@@ -7,12 +7,14 @@ mod cli;
 mod clients;
 mod config;
 mod desktop_file;
-mod dynamic_string;
+mod dynamic_value;
 mod error;
 mod gtk_helpers;
 mod image;
 #[cfg(feature = "ipc")]
 mod ipc;
+#[cfg(feature = "ipc")]
+mod ironvar;
 mod logging;
 mod macros;
 mod modules;
@@ -119,7 +121,7 @@ async fn start_ironbar() {
             ConfigLoader::load,
         );
 
-        let config = match config_res {
+        let mut config: Config = match config_res {
             Ok(config) => config,
             Err(err) => {
                 error!("{:?}", err);
@@ -129,6 +131,16 @@ async fn start_ironbar() {
 
         debug!("Loaded config file");
 
+        #[cfg(feature = "ipc")]
+        if let Some(ironvars) = config.ironvar_defaults.take() {
+            let variable_manager = ironvar::get_variable_manager();
+            for (k, v) in ironvars {
+                if write_lock!(variable_manager).set(k.clone(), v).is_err() {
+                    tracing::warn!("Ignoring invalid ironvar: '{k}'");
+                }
+            }
+        }
+
         if let Err(err) = create_bars(app, &display, wayland_client, &config) {
             error!("{:?}", err);
             exit(ExitCode::CreateBars as i32);

src/modules/custom/button.rs

@@ -1,5 +1,5 @@
 use super::{CustomWidget, CustomWidgetContext, ExecEvent};
-use crate::dynamic_string::DynamicString;
+use crate::dynamic_value::dynamic_string;
 use crate::popup::Popup;
 use crate::{build, try_send};
 use gtk::prelude::*;
@@ -25,7 +25,7 @@ impl CustomWidget for ButtonWidget {
             label.set_use_markup(true);
             button.add(&label);
 
-            DynamicString::new(&text, move |string| {
+            dynamic_string(&text, move |string| {
                 label.set_markup(&string);
                 Continue(true)
             });

src/modules/custom/image.rs

@@ -1,6 +1,6 @@
 use super::{CustomWidget, CustomWidgetContext};
 use crate::build;
-use crate::dynamic_string::DynamicString;
+use crate::dynamic_value::dynamic_string;
 use crate::image::ImageProvider;
 use gtk::prelude::*;
 use gtk::Image;
@@ -29,7 +29,7 @@ impl CustomWidget for ImageWidget {
             let gtk_image = gtk_image.clone();
             let icon_theme = context.icon_theme.clone();
 
-            DynamicString::new(&self.src, move |src| {
+            dynamic_string(&self.src, move |src| {
                 ImageProvider::parse(&src, &icon_theme, self.size)
                     .map(|image| image.load_into_image(gtk_image.clone()));
 

src/modules/custom/label.rs

@@ -1,6 +1,6 @@
 use super::{CustomWidget, CustomWidgetContext};
 use crate::build;
-use crate::dynamic_string::DynamicString;
+use crate::dynamic_value::dynamic_string;
 use gtk::prelude::*;
 use gtk::Label;
 use serde::Deserialize;
@@ -22,7 +22,7 @@ impl CustomWidget for LabelWidget {
 
         {
             let label = label.clone();
-            DynamicString::new(&self.label, move |string| {
+            dynamic_string(&self.label, move |string| {
                 label.set_markup(&string);
                 Continue(true)
             });

src/modules/custom/progress.rs

@@ -1,5 +1,5 @@
 use super::{try_get_orientation, CustomWidget, CustomWidgetContext};
-use crate::dynamic_string::DynamicString;
+use crate::dynamic_value::dynamic_string;
 use crate::modules::custom::set_length;
 use crate::script::{OutputStream, Script, ScriptInput};
 use crate::{build, send};
@@ -69,7 +69,7 @@ impl CustomWidget for ProgressWidget {
             let progress = progress.clone();
             progress.set_show_text(true);
 
-            DynamicString::new(&text, move |string| {
+            dynamic_string(&text, move |string| {
                 progress.set_text(Some(&string));
                 Continue(true)
             });

src/modules/label.rs

@@ -1,5 +1,5 @@
 use crate::config::CommonConfig;
-use crate::dynamic_string::DynamicString;
+use crate::dynamic_value::dynamic_string;
 use crate::modules::{Module, ModuleInfo, ModuleUpdateEvent, ModuleWidget, WidgetContext};
 use crate::try_send;
 use color_eyre::Result;
@@ -31,7 +31,7 @@ impl Module<Label> for LabelModule {
         tx: mpsc::Sender<ModuleUpdateEvent<Self::SendMessage>>,
         _rx: mpsc::Receiver<Self::ReceiveMessage>,
     ) -> Result<()> {
-        DynamicString::new(&self.label, move |string| {
+        dynamic_string(&self.label, move |string| {
             try_send!(tx, ModuleUpdateEvent::Update(string));
             Continue(true)
         });