Struct Watcher

pub struct Watcher(/* private fields */);

Watches one or more Sources and invokes associated callbacks when changed.

This type is useful when needing to ensure logic is executed or a value is regenerated each time one of many sources are changed.

Implementations

impl Watcher

pub fn notify(&self)

Notifies any observers of this watcher and invokes all associated callbacks.

pub fn watch<T>(&self, other: &impl Source<T>)

where T: Send + 'static,

Ensures all callbacks attached to this watcher are invoked when other is changed.

pub fn map_changed<F, T>(&self, when_changed: F) -> Dynamic<T>

where F: FnMut() -> T + Send + 'static, T: PartialEq + Send + 'static,

Returns a new dynamic populated by invoking when_changed each time any watched source is updated.

pub fn when_changed<F>(&self, when_changed: F) -> CallbackHandle

where F: FnMut() + Send + 'static,

Invokes when_changed each time any watched source is updated.

Trait Implementations

impl Clone for Watcher

fn clone(&self) -> Watcher

Returns a copy of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for Watcher

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Default for Watcher

fn default() -> Watcher

Returns the “default value” for a type.

impl Source<usize> for Watcher

fn try_map_generational<R>( &self, map: impl FnOnce(DynamicGuard<'_, usize, true>) -> R, ) -> Result<R, DeadlockError>

Maps the contents with read-only access, providing access to the value’s Generation.

fn for_each_subsequent_generational_try<F>(&self, for_each: F) -> CallbackHandle

where F: for<'a> FnMut(DynamicGuard<'_, usize, true>) -> Result<(), CallbackDisconnected> + Send + 'static,

Attaches for_each to this value so that it is invoked each time the source’s contents are updated.

fn for_each_generational_cloned_try<F>(&self, for_each: F) -> CallbackHandle

where F: FnMut(GenerationalValue<usize>) -> Result<(), CallbackDisconnected> + Send + 'static,

Invokes for_each with the current contents and each time this source’s contents are updated.

fn map_generational<R>( &self, map: impl FnOnce(DynamicGuard<'_, T, true>) -> R, ) -> R

Maps the contents with read-only access, providing access to the value’s Generation.

fn generation(&self) -> Generation

Returns the current generation of the value.

fn map_ref<R>(&self, map: impl FnOnce(&T) -> R) -> R

Maps the contents with read-only access.

fn get(&self) -> T

where T: Clone,

Returns a clone of the currently contained value.

fn try_map_ref<R>(&self, map: impl FnOnce(&T) -> R) -> Result<R, DeadlockError>

Maps the contents with read-only access.

fn try_get(&self) -> Result<T, DeadlockError>

where T: Clone,

Returns a clone of the currently contained value.

fn get_tracking_redraw(&self, context: &WidgetContext<'_>) -> T

where T: Clone, Self: Trackable + Sized,

Returns a clone of the currently contained value.

fn get_tracking_invalidate(&self, context: &WidgetContext<'_>) -> T

where T: Clone, Self: Trackable + Sized,

Returns a clone of the currently contained value.

fn for_each_subsequent_generational<F>(&self, for_each: F) -> CallbackHandle

where T: Send + 'static, F: for<'a> FnMut(DynamicGuard<'_, T, true>) + Send + 'static,

Attaches for_each to this value so that it is invoked each time the source’s contents are updated.

fn for_each_subsequent_try<F>(&self, for_each: F) -> CallbackHandle

where T: Send + 'static, F: for<'a> FnMut(&'a T) -> Result<(), CallbackDisconnected> + Send + 'static,

Attaches for_each to this value so that it is invoked each time the source’s contents are updated.

fn for_each_subsequent<F>(&self, for_each: F) -> CallbackHandle

where T: Send + 'static, F: for<'a> FnMut(&'a T) + Send + 'static,

Attaches for_each to this value so that it is invoked each time the source’s contents are updated.

fn for_each_generational_try<F>(&self, for_each: F) -> CallbackHandle

where T: Send + 'static, F: for<'a> FnMut(DynamicGuard<'_, T, true>) -> Result<(), CallbackDisconnected> + Send + 'static,

Invokes for_each with the current contents and each time this source’s contents are updated.

fn for_each_generational<F>(&self, for_each: F) -> CallbackHandle

where T: Send + 'static, F: for<'a> FnMut(DynamicGuard<'_, T, true>) + Send + 'static,

Invokes for_each with the current contents and each time this source’s contents are updated.

fn for_each_try<F>(&self, for_each: F) -> CallbackHandle

where T: Send + 'static, F: for<'a> FnMut(&'a T) -> Result<(), CallbackDisconnected> + Send + 'static,

Invokes for_each with the current contents and each time this source’s contents are updated.

fn for_each<F>(&self, for_each: F) -> CallbackHandle

where T: Send + 'static, F: for<'a> FnMut(&'a T) + Send + 'static,

Invokes for_each with the current contents and each time this source’s contents are updated.

fn for_each_cloned_try<F>(&self, for_each: F) -> CallbackHandle

where T: Clone + Send + 'static, F: FnMut(T) -> Result<(), CallbackDisconnected> + Send + 'static,

Invokes for_each with the current contents and each time this source’s contents are updated.

fn for_each_cloned<F>(&self, for_each: F) -> CallbackHandle

where T: Clone + Send + 'static, F: FnMut(T) + Send + 'static,

Invokes for_each with the current contents and each time this source’s contents are updated.

fn debounced_every(&self, period: Duration) -> Dynamic<T>

where T: PartialEq + Clone + Send + Sync + 'static,

Returns a new dynamic that contains the updated contents of this dynamic at most once every period.

fn debounced_with_delay(&self, period: Duration) -> Dynamic<T>

where T: PartialEq + Clone + Send + Sync + 'static,

Returns a new dynamic that contains the updated contents of this dynamic delayed by period. Each time this value is updated, the delay is reset.

fn map_each_generational<R, F>(&self, map: F) -> Dynamic<R>

where T: Send + 'static, F: for<'a> FnMut(DynamicGuard<'a, T, true>) -> R + Send + 'static, R: PartialEq + Send + 'static,

Creates a new dynamic value that contains the result of invoking map each time this value is changed.

fn map_each<R, F>(&self, map: F) -> Dynamic<R>

where T: Send + 'static, F: for<'a> FnMut(&'a T) -> R + Send + 'static, R: PartialEq + Send + 'static,

Creates a new dynamic value that contains the result of invoking map each time this value is changed.

fn map_each_cloned<R, F>(&self, map: F) -> Dynamic<R>

where T: Clone + Send + 'static, F: FnMut(T) -> R + Send + 'static, R: PartialEq + Send + 'static,

Creates a new dynamic value that contains the result of invoking map each time this value is changed.

fn weak_clone(&self) -> Dynamic<T>

where T: Clone + Send + 'static,

Returns a new Dynamic that contains a clone of each value from self.

fn map_each_into<U>(&self) -> Dynamic<U>

where U: PartialEq + From<T> + Send + 'static, T: Clone + Send + 'static,

Returns a new dynamic that is updated using U::from(T.clone()) each time self is updated.

fn map_each_to<U>(&self) -> Dynamic<U>

where U: PartialEq + for<'a> From<&'a T> + Send + 'static, T: Clone + Send + 'static,

Returns a new dynamic that is updated using U::from(&T) each time self is updated.