Creating backend instance in GUI. Handling topic refreshes.

pubsubman_gui/Cargo.toml

@@ -20,3 +20,5 @@ log = "0.4"
 serde = { version = "1", features = ["derive"] }
 
 env_logger = "0.10"
+tokio = { version = "1.29.1", features = ["full"] }
+pubsubman_backend = { version = "0.1.0", path = "../pubsubman_backend" }

pubsubman_gui/src/app.rs

@@ -1,61 +1,73 @@
+use pubsubman_backend::{
+    message::{BackendMessage, FrontendMessage},
+    Backend,
+};
+use tokio::sync::mpsc::{Receiver, Sender};
+
 use crate::topic::Topic;
 
-/// We derive Deserialize/Serialize so we can persist app state on shutdown.
-#[derive(serde::Deserialize, serde::Serialize)]
-#[serde(default)] // if we add new fields, give them default values when deserializing old state
 pub struct TemplateApp {
-    #[serde(skip)]
     topics: Vec<Topic>,
+    front_tx: Sender<FrontendMessage>,
+    back_rx: Receiver<BackendMessage>,
 }
 
-impl Default for TemplateApp {
-    fn default() -> Self {
+impl TemplateApp {
+    /// Called once before the first frame.
+    pub fn new(_cc: &eframe::CreationContext<'_>) -> Self {
+        let (front_tx, front_rx) = tokio::sync::mpsc::channel(2);
+        let (back_tx, back_rx) = tokio::sync::mpsc::channel(10);
+
+        tokio::spawn(async move {
+            Backend::new(back_tx, front_rx).await.init();
+        });
+
+        let front_tx_clone = front_tx.clone();
+        tokio::spawn(async move {
+            let _ = front_tx_clone
+                .send(FrontendMessage::RefreshTopicsRequest)
+                .await;
+        });
+
         Self {
-            topics: vec![
-                Topic {
-                    id: "test-topic-1".to_string(),
-                },
-                Topic {
-                    id: "test-topic-2".to_string(),
-                },
-            ],
+            topics: vec![],
+            front_tx,
+            back_rx,
         }
     }
-}
 
-impl TemplateApp {
-    /// Called once before the first frame.
-    pub fn new(cc: &eframe::CreationContext<'_>) -> Self {
-        // This is also where you can customize the look and feel of egui using
-        // `cc.egui_ctx.set_visuals` and `cc.egui_ctx.set_fonts`.
-
-        // Load previous app state (if any).
-        // Note that you must enable the `persistence` feature for this to work.
-        if let Some(storage) = cc.storage {
-            return eframe::get_value(storage, eframe::APP_KEY).unwrap_or_default();
-        }
+    fn handle_backend_message(&mut self) {
+        match self.back_rx.try_recv() {
+            Ok(message) => match message {
+                BackendMessage::TopicsUpdated(topics) => {
+                    self.topics = topics.into_iter().map(|id| Topic { id }).collect();
 
-        Default::default()
+                    let front_tx = self.front_tx.clone();
+                    tokio::spawn(async move {
+                        let _ = front_tx.send(FrontendMessage::RefreshTopicsRequest).await;
+                    });
+                }
+            },
+            Err(err) => println!("{:?}", err),
+        }
     }
 }
 
 impl eframe::App for TemplateApp {
-    /// Called by the frame work to save state before shutdown.
-    fn save(&mut self, storage: &mut dyn eframe::Storage) {
-        eframe::set_value(storage, eframe::APP_KEY, self);
-    }
-
     /// Called each time the UI needs repainting, which may be many times per second.
     /// Put your widgets into a `SidePanel`, `TopPanel`, `CentralPanel`, `Window` or `Area`.
-    fn update(&mut self, ctx: &egui::Context, _frame: &mut eframe::Frame) {
-        let Self { topics } = self;
+    fn update(&mut self, ctx: &egui::Context, frame: &mut eframe::Frame) {
+        ctx.request_repaint();
+        self.handle_backend_message();
+
+        let Self { topics, .. } = self;
 
         egui::TopBottomPanel::top("top_panel").show(ctx, |ui| {
             // The top panel is often a good place for a menu bar:
             egui::menu::bar(ui, |ui| {
                 ui.menu_button("File", |ui| {
                     if ui.button("Quit").clicked() {
-                        _frame.close();
+                        frame.close();
                     }
                 });
             });

pubsubman_gui/src/main.rs

@@ -1,7 +1,8 @@
 #![warn(clippy::all, rust_2018_idioms)]
 #![cfg_attr(not(debug_assertions), windows_subsystem = "windows")] // hide console window on Windows in release
 
-fn main() -> eframe::Result<()> {
+#[tokio::main]
+async fn main() -> eframe::Result<()> {
     env_logger::init(); // Log to stderr (if you run with `RUST_LOG=debug`).
 
     let native_options = eframe::NativeOptions::default();

pubsubman_gui/src/topic.rs

@@ -1,3 +1,4 @@
+#[derive(Debug)]
 pub struct Topic {
     pub id: String,
 }