feat: Ability to use icons for empty workspace.

This allows users of ex. `waybar` to use dynamic icons,
while still giving empty workspaces an icon instead of a number.
This is implemented by renaming new workspaces right when they
are created.
This is all behind a config option; defaults remain unchanged.

Implementing this is also an optimization for the rest of the program,
which no longer recalculates workspace naming on _every_ `Event::Window`.
Instead, only specific `Window` (and now also `Workspace`) events
will do so.

**Caveats**:
- There is a small visual artifact when opening a new workspace,
when the number gets renamed to the desired icon.. Unfortunately,
being a program reacting to sway events, I don't see a way to fix this.

**Future Possibilities**:
- Allowing specific icons for specific numbered (empty) workspaces
wouldn't be difficult to add (which would close #33).
- Which `*.change` types precisely should trigger workspace renaming
was determined with common sense, and could do with a one-over.
The relevant function is `should_rename_after_event`.

Closes #39.

Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "workstyle"
-version = "0.8.2"
+version = "0.9.0"
 authors = ["Pierre Chevalier <[email protected]>"]
 edition = "2021"
 license = "MIT"

README.md

@@ -106,6 +106,15 @@ If you prefer not to have multiple copies of the same icon when there are multip
 deduplicate_icons = true
 ```
 
+If you prefer that empty workspaces be named with an icon,
+instead of with a number, you can also specify:
+
+```toml
+[other]
+use_empty_icon = true
+empty_icon = ""
+```
+
 Note that the crate [`find_unicode`](https://github.com/pierrechevalier83/find_unicode/) can help find a unicode character directly from the command line. It now supports all of nerdfonts unicode space.
 
 Minimal waybar configuration so the workspace names are showed

src/config.rs

@@ -22,6 +22,7 @@ pub struct Other {
     pub fallback_icon: Option<String>,
     pub separator: Option<String>,
     pub deduplicate_icons: bool,
+    pub empty_icon: Option<String>,
 }
 
 impl Config {
@@ -70,6 +71,9 @@ impl Config {
             DEFAULT_SEPARATOR
         }
     }
+    pub fn empty_icon(&self) -> Option<&str> {
+        self.other.empty_icon.as_deref()
+    }
 
     pub fn path() -> Result<PathBuf> {
         let mut user_path = dirs::config_dir().context("Could not find the configuration path")?;

src/main.rs

@@ -39,6 +39,13 @@ use window_manager::{Window, WindowManager, WM};
 ///
 /// [other]
 /// deduplicate_icons = true
+///
+/// If you prefer that empty workspaces be named with an icon,
+/// instead of with a number, you can also specify:
+///
+/// [other]
+/// empty_icon = ""
+
 #[derive(Parser, Debug)]
 #[clap(version, about, long_about)]
 struct Args {
@@ -139,12 +146,19 @@ fn run() -> Result<()> {
                 .next()
                 .context("Unexpected workspace name")?;
             if new_name.is_empty() {
-                wm.rename_workspace(&name, num)?;
+                let empty_name = if let Some(icon) = config.empty_icon() {
+                    icon
+                } else {
+                    num
+                }
+                .to_string();
+
+                // Extra space matches other workspace icons.
+                wm.rename_workspace(&name, &format!("{num}{sep}{empty_name} "))?;
             } else {
                 wm.rename_workspace(&name, &format!("{num}{sep}{new_name}"))?;
             }
         }
-
         wm.wait_for_event()?;
     }
 }

src/window_manager.rs

@@ -1,4 +1,6 @@
 use crate::EnforceWindowManager;
+use log::{debug, info};
+
 use anyhow::{anyhow, bail, Context, Result};
 use hyprland::data::{Clients, Version, Workspaces};
 use hyprland::dispatch::{Dispatch, DispatchType};
@@ -8,7 +10,9 @@ use itertools::Itertools;
 use std::collections::BTreeMap;
 use std::sync::{mpsc, mpsc::Receiver};
 use std::thread;
-use swayipc::{Connection, EventStream, EventType, Node, NodeType};
+use swayipc::{
+    Connection, Event, EventStream, EventType, Node, NodeType, WindowChange, WorkspaceChange,
+};
 
 trait NodeExt {
     fn is_workspace(&self) -> bool;
@@ -287,13 +291,12 @@ impl WM for SwayOrI3 {
                 connection: Connection::new().context("Couldn't connect to WM")?,
                 events: Connection::new()
                     .context("Couldn't connect to WM")?
-                    .subscribe([EventType::Window])
-                    .context("Couldn't subscribe to events of type Window")?,
+                    .subscribe([EventType::Window, EventType::Workspace])
+                    .context("Couldn't subscribe to events of type Window and Workspace")?,
             })),
             _ => bail!("Not connecting to Sway or i3 as we've explicitly been asked not to"),
         }
     }
-
     fn get_windows_in_each_workspace(&mut self) -> Result<BTreeMap<String, Vec<Window>>> {
         self.connection
             .get_tree()
@@ -313,10 +316,54 @@ impl WM for SwayOrI3 {
     }
 
     fn wait_for_event(&mut self) -> Result<()> {
-        match self.events.next() {
-            Some(Err(e)) => Err(anyhow!(e).context("Failed to receive next event")),
-            None => bail!("Event stream ended"),
-            _ => Ok(()),
+        let next_relevant_event = self.events.find_map(move |event| {
+            if let Ok(event) = event {
+                if Self::event_is_relevant(&event) {
+                    Some(Ok(()))
+                } else {
+                    None
+                }
+            } else {
+                Some(Err(()))
+            }
+        });
+        if next_relevant_event.is_none() {
+            bail!("Event stream ended")
+        } else {
+            Ok(())
+        }
+    }
+}
+
+impl SwayOrI3 {
+    fn event_is_relevant(event: &Event) -> bool {
+        match event {
+            Event::Workspace(boxed_workspace_event) => match (*boxed_workspace_event).change {
+                ch @ WorkspaceChange::Init => {
+                    info!("Renaming on WorkspaceEvent: {:#?}", ch);
+                    true
+                }
+                ch => {
+                    debug!("Rejected Rename for WorkspaceEvent: {:#?}", ch);
+                    false
+                }
+            },
+            Event::Window(boxed_window_event) => match (*boxed_window_event).change {
+                ch @ (WindowChange::New
+                | WindowChange::Close
+                | WindowChange::Title
+                | WindowChange::Move
+                | WindowChange::Urgent
+                | WindowChange::Mark) => {
+                    info!("Renaming on WindowEvent: {:#?}", ch);
+                    true
+                }
+                ch => {
+                    debug!("Rejected Rename for WindowEvent: {:#?}", ch);
+                    false
+                }
+            },
+            _ => false,
         }
     }
 }