cushy/widgets/data.rs
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use std::fmt::Debug;
use crate::widget::{MakeWidget, WidgetRef, WrapperWidget};
use crate::widgets::Space;
/// A widget that stores arbitrary data in the widget hierachy.
///
/// This widget is useful if data needs to live as long as a related widget. For
/// example, [`ProgressBar`](crate::widgets::ProgressBar) is not a "real" widget
/// -- it implements [`MakeWidget`] and returns a customized
/// [`Slider`](crate::widgets::Slider). To ensure the indeterminant animation
/// lives only as long as the created slider does, `ProgressBar` wraps the
/// `Slider` in a `Data` widget to store the animation handle.
#[derive(Debug)]
pub struct Data<T> {
#[allow(dead_code)] // This affects formatting in Debug to rename it.
data: T,
child: WidgetRef,
}
impl<T> Data<T>
where
T: Debug,
{
/// Returns an empty widget with the contained value.
pub fn new(value: T) -> Self {
Self::new_wrapping(value, Space::clear())
}
/// Returns a new instance that wraps `widget` and stores `value`.
pub fn new_wrapping(value: T, widget: impl MakeWidget) -> Self {
Self {
data: value,
child: WidgetRef::new(widget),
}
}
/// Returns a reference to the wrapped data.
pub fn data(&self) -> &T {
&self.data
}
}
impl<T> From<T> for Data<T>
where
T: Debug,
{
fn from(value: T) -> Self {
Self::new(value)
}
}
impl<T> WrapperWidget for Data<T>
where
T: Debug + Send + 'static,
{
fn child_mut(&mut self) -> &mut WidgetRef {
&mut self.child
}
}