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Diffstat (limited to 'widget/src/lazy/component.rs')
| -rw-r--r-- | widget/src/lazy/component.rs | 20 |
1 files changed, 20 insertions, 0 deletions
diff --git a/widget/src/lazy/component.rs b/widget/src/lazy/component.rs index 1bf04195..2bdfa2c0 100644 --- a/widget/src/lazy/component.rs +++ b/widget/src/lazy/component.rs @@ -1,4 +1,5 @@ //! Build and reuse custom widgets using The Elm Architecture. +#![allow(deprecated)] use crate::core::event; use crate::core::layout::{self, Layout}; use crate::core::mouse; @@ -30,6 +31,25 @@ use std::rc::Rc; /// /// Additionally, a [`Component`] is capable of producing a `Message` to notify /// the parent application of any relevant interactions. +/// +/// # State +/// A component can store its state in one of two ways: either as data within the +/// implementor of the trait, or in a type [`State`][Component::State] that is managed +/// by the runtime and provided to the trait methods. These two approaches are not +/// mutually exclusive and have opposite pros and cons. +/// +/// For instance, if a piece of state is needed by multiple components that reside +/// in different branches of the tree, then it's more convenient to let a common +/// ancestor store it and pass it down. +/// +/// On the other hand, if a piece of state is only needed by the component itself, +/// you can store it as part of its internal [`State`][Component::State]. +#[cfg(feature = "lazy")] +#[deprecated( + since = "0.13.0", + note = "components introduce encapsulated state and hamper the use of a single source of truth. \ + Instead, leverage the Elm Architecture directly, or implement a custom widget" +)] pub trait Component<Message, Theme = crate::Theme, Renderer = crate::Renderer> { /// The internal state of this [`Component`]. type State: Default; |