cranpose-foundation 0.1.9

//! Pointer input dispatcher plumbing.
//!
//! Platform integrations enqueue pointer events here and drain them into the
//! modifier dispatch pipeline in FIFO order.

use super::types::{PointerEvent, PointerId};

#[derive(Default)]
pub struct PointerDispatcher {
    queue: Vec<(PointerId, PointerEvent)>,
}

impl PointerDispatcher {
    pub fn new() -> Self {
        Self { queue: Vec::new() }
    }

    pub fn push(&mut self, event: PointerEvent) {
        self.queue.push((event.id, event));
    }

    pub fn is_empty(&self) -> bool {
        self.queue.is_empty()
    }

    pub fn len(&self) -> usize {
        self.queue.len()
    }

    pub fn clear(&mut self) {
        self.queue.clear();
    }

    pub fn drain<F>(&mut self, mut handler: F)
    where
        F: FnMut(PointerId, PointerEvent),
    {
        for (id, event) in self.queue.drain(..) {
            handler(id, event);
        }
    }
}

#[cfg(test)]
mod tests {
    use super::*;
    use crate::nodes::input::PointerEventKind;
    use cranpose_ui_graphics::Point;

    fn event(id: u64, x: f32) -> PointerEvent {
        let position = Point { x, y: 0.0 };
        let mut event = PointerEvent::new(PointerEventKind::Move, position, position);
        event.id = id;
        event
    }

    #[test]
    fn drain_dispatches_events_in_fifo_order_and_clears_queue() {
        let mut dispatcher = PointerDispatcher::new();
        dispatcher.push(event(1, 10.0));
        dispatcher.push(event(2, 20.0));

        let mut drained = Vec::new();
        dispatcher.drain(|id, event| drained.push((id, event.position.x)));

        assert_eq!(drained, vec![(1, 10.0), (2, 20.0)]);
        assert!(dispatcher.is_empty());
    }

    #[test]
    fn clear_drops_queued_events() {
        let mut dispatcher = PointerDispatcher::new();
        dispatcher.push(event(1, 10.0));
        assert_eq!(dispatcher.len(), 1);

        dispatcher.clear();

        assert!(dispatcher.is_empty());
    }
}