use std::{pin::Pin, sync::Arc, task::{Context, Poll, Waker}};
use crossbeam::channel::{Receiver, Sender, unbounded};
use futures::Stream;
use parking_lot::RwLock;
use sdl2_sys::SDL_TextEditingEvent;
use xecs::{EntityId,System, World};
use crate::common::from_sdl_string;
#[derive(Debug,Clone)]
pub struct EventInfo {
pub timestamp : u32,
pub window_id : EntityId,
pub text : String,
pub start : u32,
pub lenght : u32
}
impl EventInfo {
pub(in crate) fn from_sdl_event(window_id : EntityId,event: SDL_TextEditingEvent) -> Self {
EventInfo {
timestamp: event.timestamp,
window_id,
text: unsafe { from_sdl_string(&event.text as *const _) },
start: event.start as _,
lenght: event.length as _
}
}
}
pub(in crate) struct TextEditingInner{
pub(in crate) tx : Sender<EventInfo>,
pub(in crate) waker : Waker
}
pub struct TextEditing{
world : Arc<RwLock<World>>,
rx : Option<(EntityId,Receiver<EventInfo>)>
}
impl TextEditing{
pub(in crate) fn from_world(world : Arc<RwLock<World>>) -> Self {
TextEditing{
world,
rx : Option::None
}
}
}
impl Stream for TextEditing{
type Item = EventInfo;
fn poll_next(mut self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Option<Self::Item>> {
if self.rx.is_none() {
let (tx,rx) = unbounded();
let id = {
let world = self.world.read();
let waker = cx.waker().clone();
world.create_entity()
.attach(TextEditingInner{ tx, waker })
.into_id()
};
self.rx.replace((id,rx));
}
let (_,rx) = self.rx.as_ref().unwrap();
if let Ok(info) = rx.try_recv() {
Poll::Ready(Some(info))
} else {
Poll::Pending
}
}
}
impl System for TextEditing{
fn world(&self) -> Arc<RwLock<World>> {
self.world.clone()
}
}
impl Drop for TextEditing{
fn drop(&mut self) {
let world = self.world.read();
if let Some((id,_)) = self.rx {
world.remove_entity(id)
}
}
}