From cb6fe05cd69e99ca0c4b40a05afb24981a288ebf Mon Sep 17 00:00:00 2001
From: Stephan Dilly <dilly.stephan@gmail.com>
Date: Tue, 23 Jun 2020 00:18:59 +0200
Subject: [PATCH] indicate whether input polling state in process of changing

---
 src/input.rs | 20 +++++++++++++++-----
 src/main.rs  |  5 ++++-
 2 files changed, 19 insertions(+), 6 deletions(-)

diff --git a/src/input.rs b/src/input.rs
index 79e65673..5556bf46 100644
--- a/src/input.rs
+++ b/src/input.rs
@@ -28,6 +28,7 @@ pub enum InputEvent {
 ///
 pub struct Input {
     desired_state: Arc<AtomicBool>,
+    current_state: Arc<AtomicBool>,
     receiver: Receiver<InputEvent>,
 }
 
@@ -37,21 +38,22 @@ impl Input {
         let (tx, rx) = unbounded();
 
         let desired_state = Arc::new(AtomicBool::new(true));
+        let current_state = Arc::new(AtomicBool::new(true));
 
         let arc_desired = Arc::clone(&desired_state);
+        let arc_current = Arc::clone(&desired_state);
 
         thread::spawn(move || {
-            let mut current_state = true;
             loop {
                 //TODO: use condvar to not busy wait
                 if arc_desired.load(Ordering::Relaxed) {
-                    if !current_state {
+                    if !arc_current.load(Ordering::Relaxed) {
                         tx.send(InputEvent::State(
                             InputState::Polling,
                         ))
                         .expect("send failed");
                     }
-                    current_state = true;
+                    arc_current.store(true, Ordering::Relaxed);
 
                     if let Some(e) = Self::poll(POLL_DURATION)
                         .expect("failed to pull events.")
@@ -60,13 +62,14 @@ impl Input {
                             .expect("send input event failed");
                     }
                 } else {
-                    if current_state {
+                    if arc_current.load(Ordering::Relaxed) {
                         tx.send(InputEvent::State(
                             InputState::Paused,
                         ))
                         .expect("send failed");
                     }
-                    current_state = false;
+
+                    arc_current.store(false, Ordering::Relaxed);
                 }
             }
         });
@@ -74,6 +77,7 @@ impl Input {
         Self {
             receiver: rx,
             desired_state,
+            current_state,
         }
     }
 
@@ -87,6 +91,12 @@ impl Input {
         self.desired_state.store(enabled, Ordering::Relaxed);
     }
 
+    ///
+    pub fn is_state_changing(&self) -> bool {
+        self.desired_state.load(Ordering::Relaxed)
+            != self.current_state.load(Ordering::Relaxed)
+    }
+
     fn poll(dur: Duration) -> anyhow::Result<Option<Event>> {
         if event::poll(dur)? {
             Ok(Some(event::read()?))
diff --git a/src/main.rs b/src/main.rs
index 6a9094fc..4ff6e18f 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -134,7 +134,10 @@ fn main() -> Result<()> {
                 draw(&mut terminal, &mut app)?;
             }
 
-            spinner.draw(&mut terminal, app.any_work_pending())?;
+            spinner.draw(
+                &mut terminal,
+                app.any_work_pending() || input.is_state_changing(),
+            )?;
 
             if app.is_quit() {
                 break;