Module events 

Rich Event System

Provides granular events for plugins to hook into terminal behavior, matching WezTerm’s event capabilities.

Architecture

The event system consists of:

• EventType: Enum of all available event types (20+ granular events)
• EventArgs: Event context passed to handlers (window, pane, tab, data)
• EventHandler: Function type for event callbacks
• EventRegistry: ⚠️ DEPRECATED - Legacy mutex-based dispatch (daemon only)

⚠️ DEPRECATION NOTICE

The EventRegistry pattern using Arc<Mutex<EventRegistry>> is deprecated in favor of pure Bevy ECS events. This provides:

• Lock-free: No mutex contention or blocking
• Type-safe: Compile-time event type checking
• ECS-native: Integrates seamlessly with Bevy’s parallel scheduler

Migration Guide

Old pattern (deprecated):

use scarab_plugin_api::events::{EventRegistry, EventType, EventArgs, EventResult};
use scarab_plugin_api::object_model::ObjectHandle;

let mut registry = EventRegistry::new();

// Register a handler for window creation
registry.register(
    EventType::WindowCreated,
    100, // priority
    "my-plugin",
    Box::new(|args| {
        println!("Window created: {:?}", args.window);
        EventResult::Continue
    })
);

// Dispatch an event
let args = EventArgs::new(EventType::WindowCreated);
let results = registry.dispatch(&args);

New pattern (Bevy ECS):

use bevy::prelude::*;
use scarab_client::events::WindowCreatedEvent;

// In your plugin's build() method:
app.add_systems(Update, handle_window_created);

// Handler system (runs in parallel with other systems):
fn handle_window_created(mut events: EventReader<WindowCreatedEvent>) {
    for event in events.read() {
        println!("Window created: {:?}", event.window);
    }
}

Where to Use Each Pattern

• Daemon plugins: Continue using DaemonEventDispatcher (wraps EventRegistry)
• Client code: Always use Bevy events from scarab-client/src/events/bevy_events.rs
• New features: Prefer Bevy events for lock-free, type-safe event handling

See crates/scarab-client/src/events/bevy_events.rs for all available typed events.

Structs

EventArgs

Event arguments passed to handlers

EventRegistryDeprecated

Central registry for event handlers

HandlerEntry

Entry in the event handler registry

Enums

EventData

Event-specific data payload

EventResult

Result returned by event handlers

EventType

Event type enumeration

Type Aliases

EventHandler

Event handler function type