From 74d2e1793c303b84ecf8578fb568ad415735fdd2 Mon Sep 17 00:00:00 2001
From: Katharina Fey <kookie@spacekookie.de>
Date: Mon, 14 Jun 2021 00:29:13 +0200
Subject: [PATCH] little: random improvements

---
 .../libs/little/little-events/src/reactor.rs  | 60 +++++++++++++++----
 development/libs/little/little/src/error.rs   |  5 ++
 development/libs/little/little/src/game.rs    | 14 +++--
 3 files changed, 61 insertions(+), 18 deletions(-)

diff --git a/development/libs/little/little-events/src/reactor.rs b/development/libs/little/little-events/src/reactor.rs
index add4c360d00..e19623bf63a 100644
--- a/development/libs/little/little-events/src/reactor.rs
+++ b/development/libs/little/little-events/src/reactor.rs
@@ -1,15 +1,42 @@
 use crate::EventHandle;
 use crossbeam_channel::{unbounded, Receiver, Sender};
 use little_core::event::{Event, Key};
-use std::collections::{HashMap, HashSet};
+use std::{
+    collections::{HashMap, HashSet},
+    sync::{
+        atomic::{AtomicBool, Ordering},
+        Arc,
+    },
+    thread,
+};
 
+/// An asynchronous event reactor
 pub struct Reactor {
     rx: Receiver<Event>,
-    handlers: HashMap<usize, Box<dyn EventHandle + 'static>>,
+    run: Arc<AtomicBool>,
+    handlers: HashMap<usize, Box<dyn EventHandle + Send + 'static>>,
     mouse: MouseState,
     key: KeyboardState,
 }
 
+/// A runtime handle to the event reactor
+pub struct ReactorHandle {
+    run: Arc<AtomicBool>,
+    tx: Sender<Event>,
+}
+
+impl ReactorHandle {
+    /// Stop the event reactor thread
+    pub fn stop(&self) {
+        self.run.store(false, Ordering::Relaxed);
+    }
+
+    /// Send an event to the reactor
+    pub fn send(&self, e: Event) {
+        self.tx.send(e).unwrap();
+    }
+}
+
 /// Encode the state the mouse can be in
 #[derive(Default)]
 struct MouseState {
@@ -28,21 +55,28 @@ struct KeyboardState {
 }
 
 impl Reactor {
-    pub fn new() -> (Sender<Event>, Self) {
+    pub fn new() -> ReactorHandle {
         let (tx, rx) = unbounded();
-        (
-            tx,
-            Self {
-                rx,
-                handlers: HashMap::new(),
-                mouse: MouseState::default(),
-                key: KeyboardState::default(),
-            },
-        )
+        let run = Arc::new(true.into());
+
+        // Create and start the event reactor
+        let this = Self {
+            rx,
+            run: Arc::clone(&run),
+            handlers: HashMap::new(),
+            mouse: MouseState::default(),
+            key: KeyboardState::default(),
+        };
+        thread::spawn(move || this.run());
+
+        // Then return a handle
+        ReactorHandle { run, tx }
     }
 
     /// Run a detached event reactor
     pub fn run(self) {
-        //
+        while self.run.load(Ordering::Relaxed) {
+            // Do things
+        }
     }
 }
diff --git a/development/libs/little/little/src/error.rs b/development/libs/little/little/src/error.rs
index dc3f8880966..e6088c3eea2 100644
--- a/development/libs/little/little/src/error.rs
+++ b/development/libs/little/little/src/error.rs
@@ -1,4 +1,5 @@
 use little_core::CoreError;
+use little_gl::GlError;
 
 pub type Result<T> = std::result::Result<T, LittleError>;
 
@@ -7,4 +8,8 @@ pub type Result<T> = std::result::Result<T, LittleError>;
 pub enum LittleError {
     #[error("little-core error: {0}")]
     Core(CoreError),
+    #[error("little-gl error: {0}")]
+    Gl(GlError),
+    #[error("little: no more layer left")]
+    NoLayer,
 }
diff --git a/development/libs/little/little/src/game.rs b/development/libs/little/little/src/game.rs
index ae1aa993a47..dbe437f2a6b 100644
--- a/development/libs/little/little/src/game.rs
+++ b/development/libs/little/little/src/game.rs
@@ -1,4 +1,4 @@
-use crate::Result;
+use crate::{LittleError, Result};
 use little_core::{
     event::{Event, Events},
     settings::GameSettings,
@@ -19,14 +19,18 @@ impl Game {
     }
 
     /// Push a new layer on top of the layer stack
-    pub fn push_layer<L: GameLayer + 'static>(&mut self, mut layer: L) {
-        layer.initialise();
+    pub fn push_layer<L: GameLayer + 'static>(&mut self, mut layer: L) -> Result<()> {
+        layer.initialise()?;
         self.layers.push_front(Box::new(layer));
+        Ok(())
     }
 
     /// Pop the last created layer from the stack
-    pub fn pop_layer(&mut self) {
-        self.layers.pop_front();
+    pub fn pop_layer(&mut self) -> Result<()> {
+        match self.layers.pop_front() {
+            Some(_) => Ok(()),
+            None => Err(LittleError::NoLayer)
+        }
     }
 
     /// Run this game