ui: refactor watch thread spawning procedure

- Remove unnecessary parameters from watch(), reload()
- Add NewThread event that adds new threads in
work_controller.static_threads hashmap
- removed obsolete field State.threads
- silence watch thread error notifications

src/bin.rs

@@ -373,8 +373,8 @@ fn run_app() -> Result<()> {
                             state.check_accounts();
                             state.redraw();
                         },
-                        ThreadEvent::ThreadJoin(id) => {
+                        ThreadEvent::NewThread(id, name) => {
-                            state.join(id);
+                            state.new_thread(id, name);
                         },
                     }
                 },

ui/src/conf/accounts.rs

@@ -38,7 +38,7 @@ use melib::StackVec;
 use text_processing::GlobMatch;
 
 use crate::types::UIEvent::{self, EnvelopeRemove, EnvelopeRename, EnvelopeUpdate, Notification};
-use crate::{workers::WorkController, StatusEvent, ThreadEvent};
+use crate::{StatusEvent, ThreadEvent};
 use crossbeam::Sender;
 use std::collections::VecDeque;
 use std::fs;
@@ -162,6 +162,7 @@ pub struct Account {
     pub(crate) runtime_settings: AccountConf,
     pub(crate) backend: Arc<RwLock<Box<dyn MailBackend>>>,
 
+    sender: Sender<ThreadEvent>,
     event_queue: VecDeque<(FolderHash, RefreshEvent)>,
     notify_fn: Arc<NotifyFn>,
 }
@@ -245,6 +246,7 @@ impl Account {
         mut settings: AccountConf,
         map: &Backends,
         work_context: WorkContext,
+        sender: Sender<ThreadEvent>,
         notify_fn: NotifyFn,
     ) -> Result<Self> {
         let s = settings.clone();
@@ -300,6 +302,7 @@ impl Account {
             settings,
             backend: Arc::new(RwLock::new(backend)),
             notify_fn,
+            sender,
 
             event_queue: VecDeque::with_capacity(8),
         })
@@ -514,16 +517,7 @@ impl Account {
         }
         Some(w)
     }
-    pub fn reload(
+    pub fn reload(&mut self, event: RefreshEvent, folder_hash: FolderHash) -> Option<UIEvent> {
-        &mut self,
-        event: RefreshEvent,
-        folder_hash: FolderHash,
-        context: (
-            &mut WorkController,
-            &Sender<ThreadEvent>,
-            &mut VecDeque<UIEvent>,
-        ),
-    ) -> Option<UIEvent> {
         if !self.folders[&folder_hash].is_available() {
             self.event_queue.push_back((folder_hash, event));
             return None;
@@ -683,6 +677,7 @@ impl Account {
                 }
                 RefreshEventKind::Failure(e) => {
                     debug!("RefreshEvent Failure: {}", e.to_string());
+                    /*
                     context
                         .1
                         .send(ThreadEvent::UIEvent(UIEvent::Notification(
@@ -691,43 +686,39 @@ impl Account {
                             Some(crate::types::NotificationType::ERROR),
                         )))
                         .expect("Could not send event on main channel");
-                    self.watch(context);
+                    */
+                    self.watch();
                 }
             }
         }
         None
     }
-    pub fn watch(
+    pub fn watch(&self) {
-        &self,
+        let sender_ = self.sender.clone();
-        context: (
-            &mut WorkController,
-            &Sender<ThreadEvent>,
-            &mut VecDeque<UIEvent>,
-        ),
-    ) {
-        let (work_controller, sender, replies) = context;
-        let sender = sender.clone();
         let r = RefreshEventConsumer::new(Box::new(move |r| {
-            sender.send(ThreadEvent::from(r)).unwrap();
+            sender_.send(ThreadEvent::from(r)).unwrap();
         }));
         match self
             .backend
             .read()
             .unwrap()
-            .watch(r, work_controller.get_context())
+            .watch(r, self.work_context.clone())
         {
             Ok(id) => {
-                work_controller
+                self.sender
-                    .static_threads
+                    .send(ThreadEvent::NewThread(
-                    .lock()
+                        id,
-                    .unwrap()
+                        format!("watching {}", self.name()).into(),
-                    .insert(id, format!("watching {}", self.name()).into());
+                    ))
+                    .unwrap();
             }
 
             Err(e) => {
-                replies.push_back(UIEvent::StatusEvent(StatusEvent::DisplayMessage(
+                self.sender
-                    e.to_string(),
+                    .send(ThreadEvent::UIEvent(UIEvent::StatusEvent(
-                )));
+                        StatusEvent::DisplayMessage(e.to_string()),
+                    )))
+                    .unwrap();
             }
         }
     }

ui/src/state.rs

@@ -137,9 +137,6 @@ impl Context {
 
     pub fn is_online(&mut self, account_pos: usize) -> bool {
         let Context {
-            ref mut work_controller,
-            ref sender,
-            ref mut replies,
             ref mut accounts,
             ref mut mailbox_hashes,
             ..
@@ -158,7 +155,7 @@ impl Context {
                  *   inform the main binary that refresh events arrived
                  * - replies to report any failures to the user
                  */
-                accounts[account_pos].watch((work_controller, sender, replies));
+                accounts[account_pos].watch();
             }
             true
         } else {
@@ -184,7 +181,6 @@ pub struct State {
     components: Vec<Box<dyn Component>>,
     pub context: Context,
     timer: thread::JoinHandle<()>,
-    threads: FnvHashMap<thread::ThreadId, (Sender<bool>, thread::JoinHandle<()>)>,
 }
 
 impl Drop for State {
@@ -232,6 +228,7 @@ impl State {
                     a_s.clone(),
                     &backends,
                     work_controller.get_context(),
+                    sender.clone(),
                     NotifyFn::new(Box::new(move |f: FolderHash| {
                         sender
                             .send(ThreadEvent::UIEvent(UIEvent::StartupCheck(f)))
@@ -286,7 +283,6 @@ impl State {
                     tx: input_thread.0,
                 },
             },
-            threads: FnvHashMap::with_capacity_and_hasher(1, Default::default()),
         };
         if s.context.settings.terminal.ascii_drawing {
             s.grid.set_ascii_drawing(true);
@@ -319,41 +315,29 @@ impl State {
                 return;
             }
             let Context {
-                ref mut work_controller,
+                ref mut accounts, ..
-                ref sender,
-                ref mut replies,
-                ref mut accounts,
-                ..
             } = &mut self.context;
 
-            if let Some(notification) =
+            if let Some(notification) = accounts[idxa].reload(event, hash) {
-                accounts[idxa].reload(event, hash, (work_controller, sender, replies))
-            {
                 if let UIEvent::Notification(_, _, _) = notification {
                     self.rcv_event(UIEvent::MailboxUpdate((idxa, hash)));
                 }
                 self.rcv_event(notification);
             }
         } else {
-            if let melib::backends::RefreshEventKind::Failure(e) = event.kind() {
+            if let melib::backends::RefreshEventKind::Failure(err) = event.kind() {
-                self.context
+                debug!(err);
-                    .sender
-                    .send(ThreadEvent::UIEvent(UIEvent::Notification(
-                        Some("watcher thread exited with error".to_string()),
-                        e.to_string(),
-                        Some(crate::types::NotificationType::ERROR),
-                    )))
-                    .expect("Could not send event on main channel");
             }
         }
     }
 
-    /// If an owned thread returns a `ThreadEvent::ThreadJoin` event to `State` then it must remove
+    pub fn new_thread(&mut self, id: thread::ThreadId, name: String) {
-    /// the thread from its list and `join` it.
+        self.context
-    pub fn join(&mut self, id: thread::ThreadId) {
+            .work_controller
-        let (tx, handle) = self.threads.remove(&id).unwrap();
+            .static_threads
-        tx.send(true).unwrap();
+            .lock()
-        handle.join().unwrap();
+            .unwrap()
+            .insert(id, name.into());
     }
 
     /// Switch back to the terminal's main screen (The command line the user sees before opening

ui/src/types.rs

@@ -46,7 +46,7 @@ pub enum StatusEvent {
 /// to the main process.
 #[derive(Debug)]
 pub enum ThreadEvent {
-    ThreadJoin(thread::ThreadId),
+    NewThread(thread::ThreadId, String),
     /// User input.
     Input(Key),
     /// User input and input as raw bytes.