make screen states a stack

src/frontend/mod.rs

@@ -1,4 +1,8 @@
-use std::{collections::BTreeMap, io, net::SocketAddr};
+use std::{
+    collections::{BTreeMap, VecDeque},
+    io,
+    net::SocketAddr,
+};
 
 use crossterm::event::{Event, EventStream, KeyCode, KeyEvent, KeyEventKind};
 use futures::{FutureExt, StreamExt};
@@ -19,7 +23,7 @@ pub type Peers = BTreeMap<SocketAddr, (String, String)>;
 
 pub struct App {
     pub state: JoecalState,
-    pub screen: CurrentScreen,
+    pub screen: VecDeque<CurrentScreen>,
     pub events: EventStream,
     // addr -> (alias, fingerprint)
     pub peers: Peers,
@@ -37,7 +41,7 @@ impl App {
     pub fn new(state: JoecalState) -> Self {
         App {
             state,
-            screen: CurrentScreen::Main,
+            screen: VecDeque::from([CurrentScreen::Main]),
             peers: Default::default(),
             events: Default::default(),
         }
@@ -48,7 +52,9 @@ impl App {
             terminal.draw(|frame| self.draw(frame))?;
             self.handle_events().await?;
 
-            if self.screen == CurrentScreen::Stopping {
+            if let Some(&top) = self.screen.back()
+                && top == CurrentScreen::Stopping
+            {
                 self.state.stop().await;
                 break;
             }
@@ -91,21 +97,30 @@ impl App {
             KeyCode::Char('q') => self.exit(),
             KeyCode::Char('s') => self.send(),
             KeyCode::Char('r') => self.recv(),
-            KeyCode::Char('d') => {}
+            KeyCode::Esc => self.pop(),
             _ => {}
         }
     }
 
     fn exit(&mut self) {
-        self.screen = CurrentScreen::Stopping;
+        self.screen.clear();
+        self.screen.push_back(CurrentScreen::Stopping);
     }
 
     fn send(&mut self) {
-        self.screen = CurrentScreen::Sending;
+        self.screen.clear();
+        self.screen.push_back(CurrentScreen::Sending);
     }
 
     fn recv(&mut self) {
-        self.screen = CurrentScreen::Receiving;
+        self.screen.clear();
+        self.screen.push_back(CurrentScreen::Receiving);
+    }
+
+    fn pop(&mut self) {
+        if self.screen.pop_back().is_none() {
+            self.screen.push_back(CurrentScreen::Main);
+        }
     }
 }
 
@@ -127,7 +142,10 @@ impl Widget for &App {
             .title_bottom(instructions.centered())
             .border_set(border::THICK);
 
-        let current_screen = format!("{:?}", self.screen);
+        let current_screen = format!(
+            "{:?}",
+            self.screen.back().cloned().unwrap_or(CurrentScreen::Main)
+        );
         let text = Text::from(Line::from(current_screen.yellow()));
 
         Paragraph::new(text)

src/frontend/ui.rs

@@ -53,6 +53,10 @@ impl App {
         frame.render_widget(self, frame.area());
         network_info(frame, footer_left);
         peers(&self.peers, frame, footer_right);
+
+        // match self.screen {
+        //     _ => {}
+        // }
     }
 }
 
@@ -65,7 +69,8 @@ fn peers(peers: &Peers, frame: &mut Frame, area: Rect) {
         let item = ListItem::new(s);
         items.push(item);
     }
-    let block = Block::default().title("Peers").borders(Borders::all());
+    let title = Line::from(" Peers ".bold()).centered();
+    let block = Block::default().title(title).borders(Borders::all());
     let list = List::new(items).block(block);
     frame.render_widget(list, area);
 }
@@ -89,7 +94,8 @@ fn network_info(frame: &mut Frame, area: Rect) {
         ListItem::new(multicast),
         ListItem::new(http),
     ];
-    let block = Block::default().title("Listeners").borders(Borders::all());
+    let title = Line::from(" Listeners ".bold()).centered();
+    let block = Block::default().title(title).borders(Borders::all());
     let list = List::new(items).block(block);
     frame.render_widget(list, area);
 }