ui: add periodic account connectivity check

1. spawn thread to send ThreadPulses to the main event loop that "parks" until unparked from State
2. State unparks thread if there are accounts that are offline
3. thread sends ThreadPulse and parks again
4. State checks accounts again and so on.

src/bin.rs

@@ -376,6 +376,7 @@ fn run_app() -> Result<()> {
                             state.render();
                         },
                         ThreadEvent::Pulse => {
+                            state.check_accounts();
                             state.redraw();
                         },
                         ThreadEvent::ThreadJoin(id) => {

ui/src/components/mail/listing.rs

@@ -222,7 +222,6 @@ impl Component for Listing {
                 .dirty_areas
                 .push_back(((mid, get_y(upper_left)), (mid, get_y(bottom_right))));
         }
-        self.dirty = false;
 
         if right_component_width == total_cols {
             if !context.is_online(self.cursor_pos.0) {
@@ -278,6 +277,7 @@ impl Component for Listing {
                 }
             }
         }
+        self.dirty = false;
     }
     fn process_event(&mut self, event: &mut UIEvent, context: &mut Context) -> bool {
         if match self.component {
@@ -468,7 +468,7 @@ impl Component for Listing {
                 self.dirty = true;
             }
             UIEvent::Resize => {
-                self.dirty = true;
+                self.set_dirty();
             }
             UIEvent::Input(Key::Up) => {
                 let amount = if self.cmd_buf.is_empty() {

ui/src/components/utilities.rs

@@ -1423,9 +1423,9 @@ impl Component for Tabbed {
             create_box(grid, area);
             let area = (
                 pos_inc(upper_left!(area), (3, 2)),
-                set_x(
-                    bottom_right!(area),
+                (
                     get_x(bottom_right!(area)).saturating_sub(3),
+                    get_y(bottom_right!(area)).saturating_sub(1),
                 ),
             );
             let mut children_maps = self.children[self.cursor_pos].get_shortcuts(context);

ui/src/state.rs

@@ -183,6 +183,7 @@ pub struct State {
     pub mode: UIMode,
     components: Vec<Box<dyn Component>>,
     pub context: Context,
+    timer: thread::JoinHandle<()>,
     threads: FnvHashMap<thread::ThreadId, (Sender<bool>, thread::JoinHandle<()>)>,
 }
 
@@ -241,6 +242,22 @@ impl State {
             .collect::<Result<Vec<Account>>>()?;
         accounts.sort_by(|a, b| a.name().cmp(&b.name()));
 
+        let timer = {
+            let sender = sender.clone();
+            thread::Builder::new().spawn(move || {
+                let sender = sender;
+                loop {
+                    thread::park();
+                    debug!("unparked");
+
+                    sender.send(ThreadEvent::Pulse).unwrap();
+                    thread::sleep(std::time::Duration::from_millis(100));
+                }
+            })
+        }?;
+
+        timer.thread().unpark();
+
         let mut s = State {
             cols,
             rows,
@@ -249,6 +266,7 @@ impl State {
             child: None,
             mode: UIMode::Normal,
             components: Vec::with_capacity(1),
+            timer,
 
             context: Context {
                 accounts,
@@ -716,4 +734,17 @@ impl State {
     fn stdout(&mut self) -> &mut StateStdout {
         self.stdout.as_mut().unwrap()
     }
+
+    pub fn check_accounts(&mut self) {
+        let mut ctr = 0;
+        for i in 0..self.context.accounts.len() {
+            if self.context.is_online(i) {
+                ctr += 1;
+            }
+        }
+        if ctr != self.context.accounts.len() {
+            debug!("unparking");
+            self.timer.thread().unpark();
+        }
+    }
 }