step 5: live Hyprland workspace buttons via EventStream

Cargo.lock

@@ -12,6 +12,7 @@ checksum = "7f202df86484c868dbad7eaa557ef785d5c66295e41b460ef922eca0723b842c"
 name = "aster"
 version = "0.1.0"
 dependencies = [
+ "futures-lite",
  "gtk4",
  "gtk4-layer-shell",
  "hyprland",

Cargo.toml

@@ -7,7 +7,8 @@ edition = "2021"
 gtk4 = { version = "0.11", features = ["v4_12"] }
 gtk4-layer-shell = "0.8"
 relm4 = { version = "0.11", features = ["macros"] }
-hyprland = "0.4.0-beta.3"
+hyprland = { version = "0.4.0-beta.3", features = ["tokio"] }
+futures-lite = "2"
 zbus = { version = "5", default-features = false, features = ["tokio"] }
 tokio = { version = "1", features = ["full"] }
 serde = { version = "1", features = ["derive"] }

src/bar/workspaces.rs

@@ -1 +1,50 @@
+use futures_lite::StreamExt;
+use gtk4::prelude::*;
+use hyprland::{
+    data::{Workspace, Workspaces},
+    event_listener::{Event, EventStream},
+    prelude::*,
+    shared::WorkspaceId,
+};
+use relm4::ComponentSender;
 
+use crate::AppInput;
+
+pub fn spawn_watcher(sender: ComponentSender<crate::App>) {
+    relm4::spawn(async move {
+        if let Ok(ws) = Workspaces::get_async().await {
+            sender.input(AppInput::WorkspaceList(ws.to_vec()));
+        }
+        if let Ok(active) = Workspace::get_active_async().await {
+            sender.input(AppInput::ActiveWorkspace(active.id));
+        }
+
+        let mut stream = EventStream::new();
+        while let Some(Ok(event)) = stream.next().await {
+            match event {
+                Event::WorkspaceChanged(data) => {
+                    sender.input(AppInput::ActiveWorkspace(data.id));
+                }
+                Event::WorkspaceAdded(_) | Event::WorkspaceDeleted(_) => {
+                    if let Ok(ws) = Workspaces::get_async().await {
+                        sender.input(AppInput::WorkspaceList(ws.to_vec()));
+                    }
+                }
+                _ => {}
+            }
+        }
+    });
+}
+
+pub fn make_button(id: WorkspaceId, name: &str, active: WorkspaceId) -> gtk4::Button {
+    let btn = gtk4::Button::with_label(name);
+    btn.add_css_class("workspace-btn");
+    if id == active {
+        btn.add_css_class("active");
+    }
+    btn.connect_clicked(move |_| {
+        use hyprland::dispatch::{Dispatch, DispatchType, WorkspaceIdentifierWithSpecial};
+        let _ = Dispatch::call(DispatchType::Workspace(WorkspaceIdentifierWithSpecial::Id(id)));
+    });
+    btn
+}

src/main.rs

@@ -4,14 +4,27 @@ mod theme;
 
 use gtk4::prelude::*;
 use gtk4_layer_shell::{Edge, Layer, LayerShell};
+use hyprland::data::Workspace;
+use hyprland::shared::WorkspaceId;
 use relm4::prelude::*;
 
-struct App;
+pub struct App {
+    workspaces: Vec<Workspace>,
+    active_ws: WorkspaceId,
+    // Stored handle so update() can manipulate the live widget directly.
+    workspace_box: gtk4::Box,
+}
 
-#[relm4::component]
+#[derive(Debug)]
+pub enum AppInput {
+    WorkspaceList(Vec<Workspace>),
+    ActiveWorkspace(WorkspaceId),
+}
+
+#[relm4::component(pub)]
 impl SimpleComponent for App {
     type Init = ();
-    type Input = ();
+    type Input = AppInput;
     type Output = ();
 
     view! {
@@ -24,11 +37,13 @@ impl SimpleComponent for App {
                 #[wrap(Some)]
                 set_start_widget = &gtk::Box {
                     set_orientation: gtk::Orientation::Horizontal,
-                    set_spacing: 4,
+                    set_spacing: 0,
                     set_margin_start: 8,
 
-                    gtk::Label {
+                    #[name = "workspace_box"]
-                        set_label: "1  2  3",
+                    gtk::Box {
+                        set_orientation: gtk::Orientation::Horizontal,
+                        set_spacing: 4,
                     }
                 },
 
@@ -54,7 +69,7 @@ impl SimpleComponent for App {
     fn init(
         _: Self::Init,
         root: Self::Root,
-        _sender: ComponentSender<Self>,
+        sender: ComponentSender<Self>,
     ) -> ComponentParts<Self> {
         root.init_layer_shell();
         root.set_layer(Layer::Top);
@@ -63,15 +78,48 @@ impl SimpleComponent for App {
         root.set_anchor(Edge::Right, true);
         root.set_exclusive_zone(32);
 
-        let model = App;
+        // Placeholder until view_output! gives us the real handle.
+        let mut model = App {
+            workspaces: vec![],
+            active_ws: 1,
+            workspace_box: gtk4::Box::new(gtk4::Orientation::Horizontal, 4),
+        };
         let widgets = view_output!();
 
+        // Swap in the actual widget so update() can reach it.
+        model.workspace_box = widgets.workspace_box.clone();
+
         theme::apply();
+        bar::workspaces::spawn_watcher(sender);
 
         ComponentParts { model, widgets }
     }
 
-    fn update(&mut self, _: Self::Input, _: ComponentSender<Self>) {}
+    fn update(&mut self, msg: Self::Input, _: ComponentSender<Self>) {
+        match msg {
+            AppInput::WorkspaceList(list) => {
+                let mut sorted = list;
+                sorted.sort_by_key(|w| w.id);
+                self.workspaces = sorted;
+            }
+            AppInput::ActiveWorkspace(id) => {
+                self.active_ws = id;
+            }
+        }
+        self.rebuild_buttons();
+    }
+}
+
+impl App {
+    fn rebuild_buttons(&self) {
+        while let Some(child) = self.workspace_box.first_child() {
+            self.workspace_box.remove(&child);
+        }
+        for ws in &self.workspaces {
+            self.workspace_box
+                .append(&bar::workspaces::make_button(ws.id, &ws.name, self.active_ws));
+        }
+    }
 }
 
 fn main() {