1
 2
 3
 4
 5
 6
 7
 8
 9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58

//! Generic event. Orchestrates multiple events so that they happen in parallel.

use amethyst::ecs::World;

use super::{BoxedGameEvent, ExecutionConditions, GameEvent};

#[derive(Default)]
pub struct ParallelEvents {
    events: Vec<Box<dyn GameEvent + Sync + Send>>,
}

impl ParallelEvents {
    /// Adds the given list of events to this event. It is assumed that the
    /// events' `start()` were already called.
    pub fn add_events(&mut self, events: impl Iterator<Item=Box<dyn GameEvent + Sync + Send>>) {
        self.events.extend(events);
    }
}

impl GameEvent for ParallelEvents {
    fn boxed_clone(&self) -> BoxedGameEvent {
        Box::new(ParallelEvents {
            events: self.events.iter().map(|event| event.boxed_clone()).collect(),
        })
    }

    fn get_execution_conditions(&self) -> ExecutionConditions {
        self.events
            .iter()
            .map(|event| event.get_execution_conditions())
            .fold(ExecutionConditions::default(), |acc, c| acc.merge_with(&c))
    }

    fn start(&mut self, world: &mut World) {
        for event in &mut self.events {
            event.start(world);
        }
    }

    fn tick(&mut self, world: &mut World, disabled_inputs: bool) {
        self.events = self.events
            .drain(..)
            .filter_map(|mut event| {
                event.tick(world, disabled_inputs);

                if event.is_complete(world) {
                    None
                } else {
                    Some(event)
                }
            })
            .collect();
    }

    fn is_complete(&self, _world: &mut World) -> bool {
        self.events.is_empty()
    }
}