pub trait GlobalState:
Any
+ Send
+ Sync
+ Debug
+ Downcast { }Expand description
Trait for app-wide state managed by the Runtime.
GlobalState is for domain state that belongs to the whole app or session:
documents, logged-in user data, navigation state, caches, settings, and
other data that should outlive an individual widget. Transient UI details
that should disappear with one widget instance belong in local widget state
instead.
§Example
#[derive(Debug, Default)]
struct TodoList {
items: Vec<String>,
}
impl GlobalState for TodoList {}
// Register with the runtime:
runtime.add_global_state(Box::new(TodoList::default()))?;Implementations§
Source§impl dyn GlobalState
impl dyn GlobalState
Sourcepub fn is<__T: GlobalState>(&self) -> bool
pub fn is<__T: GlobalState>(&self) -> bool
Returns true if the trait object wraps an object of type __T.
Sourcepub fn downcast<__T: GlobalState>(
self: Box<Self>,
) -> Result<Box<__T>, Box<Self>>
pub fn downcast<__T: GlobalState>( self: Box<Self>, ) -> Result<Box<__T>, Box<Self>>
Returns a boxed object from a boxed trait object if the underlying object is of type
__T. Returns the original boxed trait if it isn’t.
Sourcepub fn downcast_rc<__T: GlobalState>(
self: Rc<Self>,
) -> Result<Rc<__T>, Rc<Self>>
pub fn downcast_rc<__T: GlobalState>( self: Rc<Self>, ) -> Result<Rc<__T>, Rc<Self>>
Returns an Rc-ed object from an Rc-ed trait object if the underlying object is of
type __T. Returns the original Rc-ed trait if it isn’t.
Sourcepub fn downcast_ref<__T: GlobalState>(&self) -> Option<&__T>
pub fn downcast_ref<__T: GlobalState>(&self) -> Option<&__T>
Returns a reference to the object within the trait object if it is of type __T, or
None if it isn’t.
Sourcepub fn downcast_mut<__T: GlobalState>(&mut self) -> Option<&mut __T>
pub fn downcast_mut<__T: GlobalState>(&mut self) -> Option<&mut __T>
Returns a mutable reference to the object within the trait object if it is of type
__T, or None if it isn’t.
Dyn Compatibility§
This trait is dyn compatible.
In older versions of Rust, dyn compatibility was called "object safety".