Add blocking_iter to block but return a try_iter chain

src/main.rs

@@ -280,17 +280,8 @@ fn main() -> Result<(), Box<dyn Error>> {
             }
         })?;
 
-        if let Event::Input(key) = events.next()? {
-            app.error_msg = match handle_key(&mut app, key) {
-                // Exit the program
-                Ok(CalculatorResponse::Quit) => break 'outer,
-                Ok(CalculatorResponse::Continue) => None,
-                Err(e) => Some(format!("{}", e)),
-            };
-        }
-
         // Slurp events without a redraw
-        for e in events.try_iter() {
+        for e in events.blocking_iter()? {
             match e {
                 Event::Input(key) => {
                     app.error_msg = match handle_key(&mut app, key) {

src/util/event.rs

@@ -1,6 +1,7 @@
 use std::io;
+use std::iter;
 use std::sync::mpsc;
-use std::sync::mpsc::TryIter;
+use std::sync::mpsc::{Iter, TryIter};
 use std::sync::{
     atomic::{AtomicBool, Ordering},
     Arc,
@@ -54,11 +55,9 @@ impl Events {
         }
     }
 
-    pub fn next(&self) -> Result<Event<KeyEvent>, mpsc::RecvError> {
-        self.rx.recv()
-    }
-
-    pub fn try_iter(&self) -> TryIter<Event<KeyEvent>> {
-        self.rx.try_iter()
+    /// Returns a chain of the next element (blocking) and a TryIter of everything after it.
+    /// Useful for reading a single Iterator of all elements once after blocking, so there are not too many UI redraws.
+    pub fn blocking_iter(&self) -> Result<iter::Chain<iter::Once<Event<KeyEvent>>,TryIter<Event<KeyEvent>>>, mpsc::RecvError> {
+        Ok(iter::once(self.rx.recv()?).chain(self.rx.try_iter()).into_iter())
     }
 }