cursive/examples/user_data.rs

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2019-03-04 02:06:50 +00:00
//! This example shows the usage of user data.
//!
//! This lets you attach data to the main `Cursive` root, which can simplify
//! communication in simple applications.
//!
//! `Cursive::set_user_data` is used to store or update the user data, while
//! `Cursive::user_data` and `Cursive::with_user_data` can access it, if they
//! know the exact type.
use cursive::views::Dialog;
use cursive::Cursive;
struct Data {
counter: u32,
}
fn main() {
let mut siv = Cursive::default();
// `Cursive::set_user_data` accepts any `T: Any`, which includes most
// owned types
siv.set_user_data(Data { counter: 0 });
siv.add_layer(
Dialog::text("This uses some user data!")
.title("User data example")
.button("Increment", |s| {
// `Cursive::with_user_data()` is an easy way to run a closure
// on the data.
s.with_user_data(|data: &mut Data| {
data.counter += 1;
});
})
.button("Show", |s| {
// `Cursive::user_data()` returns a reference to the data.
let value = s.user_data::<Data>().unwrap().counter;
s.add_layer(Dialog::info(format!("Current value: {}", value)));
})
.button("Quit", Cursive::quit),
);
siv.run();
}