Module reactive 

Reactive attribute system for textual-rs.

Provides automatic change detection, repaint/layout invalidation, and watcher dispatch for widget fields annotated with #[reactive] or #[var].

Overview

This module defines the core types that power the reactive system:

• ReactiveFlags — controls what happens when a reactive field changes
• ReactiveChange — records a single field change with old/new values
• ReactiveCtx — context passed to setters, accumulates changes
• ReactiveWidget — trait implemented by #[derive(Reactive)]

Usage

use textual_macros::Reactive;

#[derive(Reactive)]
struct MyWidget {
    #[reactive]
    label: String,

    #[reactive(layout)]
    size: usize,

    #[var]
    counter: u32,
}

Structs

ReactiveChange

Records a single field change during an event dispatch cycle.

ReactiveCtx

Context passed to reactive setters. Records changes and provides node identity.

ReactiveFieldDescriptor

Static descriptor for a single reactive field on a widget.

ReactiveFlags

Flags controlling what happens when a reactive field changes.

ReactivePhaseResult

Outcome of running the reactive phase for a single widget.

RuntimeReactiveEntry

Queued reactive work unit drained by the runtime event loop.

Constants

MAX_REACTIVE_ITERATIONS

Maximum number of reactive iterations before the runtime considers a cycle and stops processing. Protects against infinite watcher loops where one watcher’s side-effect triggers another change ad infinitum.

Traits

ReactiveWidget

Trait implemented by #[derive(Reactive)] structs.

Functions

enqueue_runtime_reactive_entry

Enqueue a reactive work item to be processed in the runtime reactive phase.

run_reactive_phase

Run the reactive phase for a single widget: drain changes, call watchers, and repeat until no new changes are produced (or cycle limit is hit).

run_reactive_phase_with_dispatch

Run the reactive phase with a custom dispatch function.

take_runtime_reactive_entries

Drain all queued runtime reactive work items.