04_timer/
04_timer.rs

1//! Example 04: Timer
2//!
3//! Demonstrates streaming updates without user interaction.
4//! The timer updates automatically every second.
5//!
6//! Run with: cargo run -p telex-tui --example 04_timer
7
8use crossterm::event::KeyCode;
9use crossterm::style::Color;
10use std::time::Duration;
11use telex::prelude::*;
12
13telex::require_api!(0, 2);
14
15fn main() {
16    telex::run_with_theme(App, telex::theme::Theme::nord()).unwrap();
17}
18
19struct App;
20
21impl Component for App {
22    fn render(&self, cx: Scope) -> View {
23        let show_help = state!(cx, || false);
24
25        // F1 toggles help
26        cx.use_command(
27            KeyBinding::key(KeyCode::F(1)),
28            with!(show_help => move || show_help.update(|v| *v = !*v)),
29        );
30
31        // Stream that yields elapsed seconds
32        let elapsed = stream!(cx, || {
33            (0u64..).inspect(|&s| {
34                if s > 0 {
35                    std::thread::sleep(Duration::from_secs(1));
36                }
37            })
38        });
39
40        let seconds = elapsed.get();
41        let is_running = elapsed.is_loading();
42
43        // Format as MM:SS
44        let minutes = seconds / 60;
45        let secs = seconds % 60;
46        let time_display = format!("{:02}:{:02}", minutes, secs);
47
48        View::vstack()
49            .child(View::styled_text("Timer").color(Color::Cyan).bold().build())
50            .child(View::gap(1))
51            .child(
52                View::hstack()
53                    .child(View::styled_text(&time_display).bold().build())
54                    .child(if is_running {
55                        View::styled_text(" ●").color(Color::Green).build()
56                    } else {
57                        View::styled_text(" ○").dim().build()
58                    })
59                    .build(),
60            )
61            .child(View::gap(1))
62            .child(View::styled_text("F1 help • Ctrl+Q quit").dim().build())
63            .child(
64                View::modal()
65                    .visible(show_help.get())
66                    .title("Example 04: Timer")
67                    .on_dismiss(with!(show_help => move || show_help.set(false)))
68                    .child(
69                        View::vstack()
70                            .child(View::styled_text("What you're seeing").bold().build())
71                            .child(View::text("• stream!() macro for background data"))
72                            .child(View::text("• Auto-updating UI without user input"))
73                            .child(View::text("• Green dot = stream is running"))
74                            .child(View::gap(1))
75                            .child(View::styled_text("Key concepts").bold().build())
76                            .child(View::text("• Streams run in background threads"))
77                            .child(View::text("• Each yielded value triggers a re-render"))
78                            .child(View::text("• is_loading() tells you if stream is active"))
79                            .child(View::gap(1))
80                            .child(View::styled_text("Try this").bold().build())
81                            .child(View::text("• Just watch - the timer ticks automatically"))
82                            .child(View::text("• No button presses needed for updates"))
83                            .child(View::gap(1))
84                            .child(View::styled_text("Next up").bold().build())
85                            .child(View::text("→ 05_todo_list: text input and list management"))
86                            .child(View::gap(1))
87                            .child(View::styled_text("Press Escape to close").dim().build())
88                            .build(),
89                    )
90                    .build(),
91            )
92            .build()
93    }
94}
04_timer/04_timer.rs

04_timer/
04_timer.rs
