Fix event passing from agent to/from component

Cargo.toml

@@ -9,6 +9,7 @@ crate-type = ["cdylib", "rlib"]
 
 [dependencies]
 yew = "0.17"
+#yew = { path = "/home/rob/dev/yew/yew" }
 yewtil = "0.3.1"
 wasm-bindgen = "0.2"
 gloo-events = "0.1.0"
@@ -23,4 +24,5 @@ features = [
   "console",
   "AudioContext",
   "AudioBuffer",
+  "HtmlCanvasElement",
 ]

src/agents/audio_agent.rs

@@ -1,36 +1,54 @@
 use js_sys::Uint8Array;
+use std::collections::HashSet;
+use std::rc::Rc;
 use wasm_bindgen::JsValue;
 use wasm_bindgen_futures::JsFuture;
+use web_sys::console;
 use web_sys::{AudioContext, File};
 use yew::services::reader::{FileChunk, ReaderTask};
-use yew::services::{ConsoleService, ReaderService};
+use yew::services::{ConsoleService as Console, ReaderService};
 use yew::worker::*;
 use yewtil::future::LinkFuture;
 
 const FILE_LOAD_CHUNK_SIZE: usize = 4096;
 
+pub type AudioData = Rc<web_sys::AudioBuffer>;
+
+#[derive(Debug)]
 pub struct AudioAgent {
     link: AgentLink<Self>,
     reader_service: ReaderService,
     reader_task: Option<ReaderTask>,
     audio_context: AudioContext,
     bytes_buffer: Vec<u8>,
+    subscribers: HashSet<HandlerId>,
 }
 
+#[derive(Debug)]
 pub enum Request {
     LoadSamplesFromFile(File),
 }
 
+#[derive(Debug)]
+pub enum Response {
+    SamplesLoaded(AudioData),
+}
+
+#[derive(Debug)]
 pub enum Msg {
     FileProgress(Option<FileChunk>),
     AudioDecoded(JsValue),
     AudioDecodingFailed(JsValue),
 }
 
+// Convert the result of AudioContext.decode_audio_data():
 impl From<Result<JsValue, JsValue>> for Msg {
     fn from(item: Result<JsValue, JsValue>) -> Self {
         match item {
-            Ok(samples) => Msg::AudioDecoded(samples),
+            Ok(samples) => {
+                console::log_2(&"Got js value".into(), &samples);
+                Msg::AudioDecoded(samples)
+            }
             Err(e) => Msg::AudioDecodingFailed(e),
         }
     }
@@ -40,7 +58,7 @@ impl Agent for AudioAgent {
     type Reach = Context<Self>;
     type Message = Msg;
     type Input = Request;
-    type Output = ();
+    type Output = Response;
 
     fn create(link: AgentLink<Self>) -> Self {
         // TODO: where should the AudioContext be initialized and stored?
@@ -50,6 +68,7 @@ impl Agent for AudioAgent {
             reader_task: None,
             audio_context: AudioContext::new().unwrap(),
             bytes_buffer: vec![],
+            subscribers: HashSet::new(),
         }
     }
 
@@ -60,17 +79,20 @@ impl Agent for AudioAgent {
             }
             Msg::FileProgress(Some(FileChunk::Finished)) => {
                 if let Err(e) = self.handle_file_loaded() {
-                    ConsoleService::error(&e);
+                    Console::error(&e);
                 }
             }
             Msg::AudioDecoded(samples) => {
                 let audio_buffer = web_sys::AudioBuffer::from(samples);
-                let data = audio_buffer.get_channel_data(0).unwrap(); // TODO: error handling
-                let vec: Vec<f32> = data.to_vec();
-                ConsoleService::log(&format!("Success decoding: {:?}", vec));
+                let audio_data = Rc::new(audio_buffer);
+
+                for subscriber in self.subscribers.iter() {
+                    self.link
+                        .respond(*subscriber, Response::SamplesLoaded(audio_data.clone()));
+                }
             }
             Msg::AudioDecodingFailed(err) => {
-                ConsoleService::error(&format!("Error decoding: {:?}", err));
+                Console::error(&format!("Error decoding: {:?}", err));
             }
             _ => (),
         };
@@ -81,28 +103,41 @@ impl Agent for AudioAgent {
             Request::LoadSamplesFromFile(file) => self.load_samples_from_file(file),
         };
     }
+
+    fn connected(&mut self, id: HandlerId) {
+        // if id.is_respondable() {
+        Console::log(&format!("Subscriber connected: {:?}", id));
+        self.subscribers.insert(id);
+        //
+    }
+
+    fn disconnected(&mut self, id: HandlerId) {
+        self.subscribers.remove(&id);
+    }
 }
 
 impl AudioAgent {
-    fn load_samples_from_file(&mut self, file: File) -> Result<(), String> {
+    fn load_samples_from_file(&mut self, file: File) {
         self.bytes_buffer = Vec::with_capacity(file.size() as usize);
         let cb = self.link.callback(Msg::FileProgress);
 
+        // TODO: error handling
         let task = self
             .reader_service
             .read_file_by_chunks(file, cb, FILE_LOAD_CHUNK_SIZE)
-            .map_err(|e| e.to_string())?;
+            .map_err(|e| e.to_string())
+            .unwrap();
 
         self.reader_task = Some(task);
-
-        Ok(())
     }
 
     fn handle_file_progress(&mut self, mut data: Vec<u8>, _progress: f32) {
         self.bytes_buffer.append(&mut data);
     }
 
-    fn handle_file_loaded(&self) -> Result<(), String> {
+    fn handle_file_loaded(&mut self) -> Result<(), String> {
+        self.reader_task = None;
+
         let audio_data = Uint8Array::from(&self.bytes_buffer[..]);
         match self.audio_context.decode_audio_data(&audio_data.buffer()) {
             Ok(promise) => {

src/canvas.rs

@@ -1,22 +1,46 @@
+use crate::agents::audio_agent::{self, AudioAgent, AudioData};
+use web_sys::HtmlCanvasElement;
+use yew::agent::Bridged;
 use yew::prelude::*;
+use yew::Bridge;
 
-pub struct Canvas {}
+pub struct Canvas {
+    _audio_agent: Box<dyn Bridge<AudioAgent>>,
+    canvas_node: NodeRef,
+    audio_data: Option<AudioData>,
+}
 
+#[derive(Debug)]
 pub enum Msg {
     Reset,
-    SamplesLoaded,
+    HandleAudioAgentResponse(audio_agent::Response),
 }
 
 impl Component for Canvas {
     type Message = Msg;
     type Properties = ();
 
-    fn create(_: Self::Properties, _: ComponentLink<Self>) -> Self {
-        Self {}
+    fn create(_: Self::Properties, link: ComponentLink<Self>) -> Self {
+        Self {
+            _audio_agent: AudioAgent::bridge(link.callback(Msg::HandleAudioAgentResponse)),
+            canvas_node: NodeRef::default(),
+            audio_data: None,
+        }
     }
 
-    fn update(&mut self, _: Self::Message) -> ShouldRender {
-        true
+    fn update(&mut self, msg: Self::Message) -> ShouldRender {
+        match msg {
+            Msg::Reset => {
+                self.audio_data = None;
+                self.redraw_canvas();
+            }
+            Msg::HandleAudioAgentResponse(audio_data) => match audio_data {
+                audio_agent::Response::SamplesLoaded(audio_data) => {
+                    self.handle_samples_loaded(audio_data)
+                }
+            },
+        };
+        false
     }
 
     fn change(&mut self, _: Self::Properties) -> ShouldRender {
@@ -24,6 +48,19 @@ impl Component for Canvas {
     }
 
     fn view(&self) -> Html {
-        html! { <canvas width="800" height="300" style="border: 1px solid grey"></canvas> }
+        html! { <canvas ref=self.canvas_node.clone() width="800" height="300" style="border: 1px solid grey"></canvas> }
+    }
+}
+
+impl Canvas {
+    fn handle_samples_loaded(&mut self, audio_data: AudioData) {
+        self.audio_data = Some(audio_data);
+        self.redraw_canvas();
+    }
+
+    fn redraw_canvas(&mut self) {
+        let canvas_element = self.canvas_node.cast::<HtmlCanvasElement>().unwrap();
+        let _context = canvas_element.get_context("2d").unwrap();
+        // TODO: draw canvas...
     }
 }

src/controls.rs

@@ -1,5 +1,6 @@
 use crate::agents::audio_agent::{self, AudioAgent};
 use web_sys::HtmlInputElement;
+use yew::agent::Dispatched;
 use yew::agent::Dispatcher;
 use yew::prelude::*;
 use yew::services::ConsoleService;