feat: new label module

Takes a text label, with the ability to include embedded scripts.

Resolves #80.

src/modules/label.rs

@@ -0,0 +1,62 @@
+use crate::config::CommonConfig;
+use crate::dynamic_string::DynamicString;
+use crate::modules::{Module, ModuleInfo, ModuleUpdateEvent, ModuleWidget, WidgetContext};
+use crate::try_send;
+use color_eyre::Result;
+use glib::Continue;
+use gtk::prelude::*;
+use gtk::Label;
+use serde::Deserialize;
+use tokio::sync::mpsc;
+
+#[derive(Debug, Deserialize, Clone)]
+pub struct LabelModule {
+    label: String,
+
+    #[serde(flatten)]
+    pub common: Option<CommonConfig>,
+}
+
+impl Module<Label> for LabelModule {
+    type SendMessage = String;
+    type ReceiveMessage = ();
+
+    fn name() -> &'static str {
+        "label"
+    }
+
+    fn spawn_controller(
+        &self,
+        _info: &ModuleInfo,
+        tx: mpsc::Sender<ModuleUpdateEvent<Self::SendMessage>>,
+        _rx: mpsc::Receiver<Self::ReceiveMessage>,
+    ) -> Result<()> {
+        DynamicString::new(&self.label, move |string| {
+            try_send!(tx, ModuleUpdateEvent::Update(string));
+            Continue(true)
+        });
+
+        Ok(())
+    }
+
+    fn into_widget(
+        self,
+        context: WidgetContext<Self::SendMessage, Self::ReceiveMessage>,
+        _info: &ModuleInfo,
+    ) -> Result<ModuleWidget<Label>> {
+        let label = Label::new(None);
+
+        {
+            let label = label.clone();
+            context.widget_rx.attach(None, move |string| {
+                label.set_label(&string);
+                Continue(true)
+            });
+        }
+
+        Ok(ModuleWidget {
+            widget: label,
+            popup: None,
+        })
+    }
+}

src/modules/mod.rs

@@ -10,6 +10,7 @@ pub mod clipboard;
 pub mod clock;
 pub mod custom;
 pub mod focused;
+pub mod label;
 pub mod launcher;
 #[cfg(feature = "music")]
 pub mod music;