layer-shika/examples/event-loop/README.md

Event Loop Integration Examples

This directory contains examples demonstrating how to integrate custom event sources with layer-shika's event loop.

Examples

Timer (timer.rs)

Demonstrates how to add periodic timers to update UI elements (e.g., a clock).

cargo run --bin timer

Channel (channel.rs)

Shows how to use channels for communication between background threads and the UI. Useful for async operations, network requests, or any off-main-thread work.

cargo run --bin channel

Custom Event Source (custom_source.rs)

Demonstrates adding custom file descriptor-based event sources for I/O monitoring.

cargo run --bin custom-source

Key Concepts

All examples use shell.event_loop_handle() to get a handle that allows registering event sources with the main event loop. The callbacks receive &mut AppState which provides access to window components and output information.

Timer Pattern

let handle = shell.event_loop_handle();
handle.add_timer(Duration::from_secs(1), |_instant, app_state| {
    // Update UI components here
    TimeoutAction::ToInstant(Instant::now() + Duration::from_secs(1))
})?;

Channel Pattern

let handle = shell.event_loop_handle();
let (_token, sender) = handle.add_channel(|message: MyMessage, app_state| {
    // Handle messages from background threads
})?;

// Send from another thread
std::thread::spawn(move || {
    sender.send(MyMessage::Update("data".into())).unwrap();
});

File Descriptor Pattern

use layer_shika::calloop::{Generic, Interest, Mode};

let handle = shell.event_loop_handle();
handle.add_fd(file, Interest::READ, Mode::Level, |app_state| {
    // Handle I/O readiness
})?;