incular-core 0.1.0

Platform-independent foundation types for Incular
Documentation 
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//! Renderer-neutral widget contracts.

use crate::{BuildContext, Key};
use std::rc::Rc;

/// Base contract shared by stateless and stateful widget descriptions.
///
/// Core deliberately does not prescribe how a widget is mounted, laid out, or
/// painted. Higher-level crates can add those concerns while still accepting
/// any type implementing this identity contract. The default key is absent,
/// which gives a widget positional identity in a local reconciliation pass.
pub trait Widget: 'static {
    /// Returns the optional local identity used by reconciliation.
    fn key(&self) -> Option<&dyn Key> {
        None
    }
}

/// A type-erased widget description suitable for child collections.
pub type WidgetRef = Rc<dyn Widget>;

/// Optional build contract for widget crates that want to construct a child
/// description from a context. It is separate from [`Widget`] so core does
/// not force every renderer-specific widget to choose a child representation.
pub trait BuildableWidget: Widget {
    fn build(&self, context: &BuildContext) -> WidgetRef;
}