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Diffstat (limited to 'native/src/widget/operation.rs')
-rw-r--r-- | native/src/widget/operation.rs | 112 |
1 files changed, 0 insertions, 112 deletions
diff --git a/native/src/widget/operation.rs b/native/src/widget/operation.rs deleted file mode 100644 index 53688a21..00000000 --- a/native/src/widget/operation.rs +++ /dev/null @@ -1,112 +0,0 @@ -//! Query or update internal widget state. -pub mod focusable; -pub mod scrollable; -pub mod text_input; - -pub use focusable::Focusable; -pub use scrollable::Scrollable; -pub use text_input::TextInput; - -use crate::widget::Id; - -use std::any::Any; -use std::fmt; - -/// A piece of logic that can traverse the widget tree of an application in -/// order to query or update some widget state. -pub trait Operation<T> { - /// Operates on a widget that contains other widgets. - /// - /// The `operate_on_children` function can be called to return control to - /// the widget tree and keep traversing it. - fn container( - &mut self, - id: Option<&Id>, - operate_on_children: &mut dyn FnMut(&mut dyn Operation<T>), - ); - - /// Operates on a widget that can be focused. - fn focusable(&mut self, _state: &mut dyn Focusable, _id: Option<&Id>) {} - - /// Operates on a widget that can be scrolled. - fn scrollable(&mut self, _state: &mut dyn Scrollable, _id: Option<&Id>) {} - - /// Operates on a widget that has text input. - fn text_input(&mut self, _state: &mut dyn TextInput, _id: Option<&Id>) {} - - /// Operates on a custom widget with some state. - fn custom(&mut self, _state: &mut dyn Any, _id: Option<&Id>) {} - - /// Finishes the [`Operation`] and returns its [`Outcome`]. - fn finish(&self) -> Outcome<T> { - Outcome::None - } -} - -/// The result of an [`Operation`]. -pub enum Outcome<T> { - /// The [`Operation`] produced no result. - None, - - /// The [`Operation`] produced some result. - Some(T), - - /// The [`Operation`] needs to be followed by another [`Operation`]. - Chain(Box<dyn Operation<T>>), -} - -impl<T> fmt::Debug for Outcome<T> -where - T: fmt::Debug, -{ - fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { - match self { - Self::None => write!(f, "Outcome::None"), - Self::Some(output) => write!(f, "Outcome::Some({output:?})"), - Self::Chain(_) => write!(f, "Outcome::Chain(...)"), - } - } -} - -/// Produces an [`Operation`] that applies the given [`Operation`] to the -/// children of a container with the given [`Id`]. -pub fn scoped<T: 'static>( - target: Id, - operation: impl Operation<T> + 'static, -) -> impl Operation<T> { - struct ScopedOperation<Message> { - target: Id, - operation: Box<dyn Operation<Message>>, - } - - impl<Message: 'static> Operation<Message> for ScopedOperation<Message> { - fn container( - &mut self, - id: Option<&Id>, - operate_on_children: &mut dyn FnMut(&mut dyn Operation<Message>), - ) { - if id == Some(&self.target) { - operate_on_children(self.operation.as_mut()); - } else { - operate_on_children(self); - } - } - - fn finish(&self) -> Outcome<Message> { - match self.operation.finish() { - Outcome::Chain(next) => { - Outcome::Chain(Box::new(ScopedOperation { - target: self.target.clone(), - operation: next, - })) - } - outcome => outcome, - } - } - } - - ScopedOperation { - target, - operation: Box::new(operation), - } -} |