use collections::HashMap;
#[derive(Debug, Hash, PartialEq, Eq)]
pub(crate) enum SerialKind {
DataDevice,
InputMethod,
MouseEnter,
MousePress,
KeyPress,
}
#[derive(Clone, Copy, Debug, Eq, PartialEq)]
pub(crate) struct Serial(u32);
impl Serial {
pub(super) fn as_raw(self) -> u32 {
self.0
}
}
#[derive(Clone, Copy, Debug, Eq, PartialEq)]
pub(crate) struct SelectionSerial(Serial);
impl SelectionSerial {
pub(super) fn as_raw(self) -> u32 {
self.0.as_raw()
}
}
#[derive(Debug)]
pub(crate) struct SerialTracker {
serials: HashMap<SerialKind, Serial>,
selection_serial: Option<SelectionSerial>,
}
impl SerialTracker {
pub fn new() -> Self {
Self {
serials: HashMap::default(),
selection_serial: None,
}
}
pub fn update(&mut self, kind: SerialKind, value: u32) {
let serial = Serial(value);
if matches!(&kind, SerialKind::KeyPress | SerialKind::MousePress) {
self.selection_serial = Some(SelectionSerial(serial));
}
self.serials.insert(kind, serial);
}
pub fn get(&self, kind: SerialKind) -> Serial {
self.serials.get(&kind).copied().unwrap_or(Serial(0))
}
pub fn selection_serial(&self) -> Option<SelectionSerial> {
self.selection_serial
}
}
#[cfg(test)]
mod tests {
use super::*;
fn raw_selection_serial(serial_tracker: &SerialTracker) -> Option<u32> {
serial_tracker
.selection_serial()
.map(SelectionSerial::as_raw)
}
#[test]
fn test_selection_serial_ignores_unrelated_serial_kinds() {
let mut serial_tracker = SerialTracker::new();
serial_tracker.update(SerialKind::MousePress, 3783);
serial_tracker.update(SerialKind::InputMethod, 5011);
serial_tracker.update(SerialKind::KeyPress, 3787);
serial_tracker.update(SerialKind::MouseEnter, 6000);
serial_tracker.update(SerialKind::DataDevice, 7000);
assert_eq!(raw_selection_serial(&serial_tracker), Some(3787));
}
#[test]
fn test_selection_serial_uses_mouse_press_without_key_press() {
let mut serial_tracker = SerialTracker::new();
serial_tracker.update(SerialKind::MousePress, 3783);
assert_eq!(raw_selection_serial(&serial_tracker), Some(3783));
}
#[test]
fn test_selection_serial_uses_event_arrival_order_across_rollover() {
let mut serial_tracker = SerialTracker::new();
serial_tracker.update(SerialKind::KeyPress, 0xffff_fff0);
serial_tracker.update(SerialKind::MousePress, 0x0000_0010);
assert_eq!(raw_selection_serial(&serial_tracker), Some(0x0000_0010));
}
#[test]
fn test_selection_serial_is_unavailable_without_eligible_input() {
let mut serial_tracker = SerialTracker::new();
assert_eq!(raw_selection_serial(&serial_tracker), None);
serial_tracker.update(SerialKind::InputMethod, 5011);
serial_tracker.update(SerialKind::MouseEnter, 6000);
serial_tracker.update(SerialKind::DataDevice, 7000);
assert_eq!(raw_selection_serial(&serial_tracker), None);
}
#[test]
fn test_zero_is_a_valid_selection_serial() {
let mut serial_tracker = SerialTracker::new();
serial_tracker.update(SerialKind::KeyPress, 0);
assert_eq!(raw_selection_serial(&serial_tracker), Some(0));
}
}