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use std::any::Any;
use { GenericEvent, CURSOR };
pub trait CursorEvent: Sized {
fn from_cursor(cursor: bool, old_event: &Self) -> Option<Self>;
fn cursor<U, F>(&self, f: F) -> Option<U>
where F: FnMut(bool) -> U;
fn cursor_args(&self) -> Option<bool> {
self.cursor(|val| val)
}
}
impl<T: GenericEvent> CursorEvent for T {
fn from_cursor(cursor: bool, old_event: &Self) -> Option<Self> {
GenericEvent::from_args(CURSOR, &cursor as &Any, old_event)
}
fn cursor<U, F>(&self, mut f: F) -> Option<U>
where F: FnMut(bool) -> U
{
if self.event_id() != CURSOR {
return None;
}
self.with_args(|any| {
if let Some(&cursor) = any.downcast_ref::<bool>() {
Some(f(cursor))
} else {
panic!("Expected bool")
}
})
}
}
#[cfg(test)]
mod tests {
use super::*;
#[test]
fn test_input_cursor() {
use super::super::Input;
let e = Input::Cursor(false);
let x: Option<Input> = CursorEvent::from_cursor(true, &e);
let y: Option<Input> = x.clone().unwrap().cursor(|cursor|
CursorEvent::from_cursor(cursor, x.as_ref().unwrap())).unwrap();
assert_eq!(x, y);
}
#[test]
fn test_event_cursor() {
use Event;
use super::super::Input;
let e = Event::Input(Input::Cursor(false));
let x: Option<Event> = CursorEvent::from_cursor(true, &e);
let y: Option<Event> = x.clone().unwrap().cursor(|cursor|
CursorEvent::from_cursor(cursor, x.as_ref().unwrap())).unwrap();
assert_eq!(x, y);
}
}