Implement decode_audio_data step

Cargo.toml

@@ -9,6 +9,7 @@ crate-type = ["cdylib", "rlib"]
 
 [dependencies]
 yew = "0.17"
+yewtil = "0.3.1"
 wasm-bindgen = "0.2"
 gloo-events = "0.1.0"
 js-sys = "0.3.44"

src/agents/audio_agent.rs

@@ -1,12 +1,18 @@
-use web_sys::File;
+use js_sys::Uint8Array;
+use wasm_bindgen::JsValue;
+use wasm_bindgen_futures::JsFuture;
+use web_sys::{AudioContext, File};
 use yew::services::reader::{FileChunk, ReaderTask};
 use yew::services::{ConsoleService, ReaderService};
 use yew::worker::*;
+use yewtil::future::LinkFuture;
 
 pub struct AudioAgent {
     link: AgentLink<Self>,
     reader_service: ReaderService,
     reader_task: Option<ReaderTask>,
+    audio_context: AudioContext,
+    bytes_buffer: Vec<u8>,
 }
 
 pub enum Request {
@@ -15,6 +21,17 @@ pub enum Request {
 
 pub enum Msg {
     FileProgress(Option<FileChunk>),
+    AudioDecoded(JsValue),
+    AudioDecodingFailed(JsValue),
+}
+
+impl From<Result<JsValue, JsValue>> for Msg {
+    fn from(item: Result<JsValue, JsValue>) -> Self {
+        match item {
+            Ok(samples) => Msg::AudioDecoded(samples),
+            Err(e) => Msg::AudioDecodingFailed(e),
+        }
+    }
 }
 
 impl Agent for AudioAgent {
@@ -24,21 +41,35 @@ impl Agent for AudioAgent {
     type Output = ();
 
     fn create(link: AgentLink<Self>) -> Self {
+        // TODO: where should the AudioContext be initialized and stored?
         Self {
             link,
             reader_service: ReaderService::new(),
             reader_task: None,
+            audio_context: AudioContext::new().unwrap(),
+            bytes_buffer: vec![],
         }
     }
 
     fn update(&mut self, msg: Self::Message) {
         match msg {
-            Msg::FileProgress(Some(chunk)) => {
-                if let Err(e) = self.handle_file_progress(chunk) {
+            Msg::FileProgress(Some(FileChunk::DataChunk { data, progress })) => {
+                if let Err(e) = self.handle_file_progress(data, progress) {
                     ConsoleService::error(&e);
                 }
             }
-            Msg::FileProgress(None) => (),
+            Msg::FileProgress(Some(FileChunk::Finished)) => {
+                if let Err(e) = self.handle_file_loaded() {
+                    ConsoleService::error(&e);
+                }
+            }
+            Msg::AudioDecoded(samples) => {
+                ConsoleService::log(&format!("Success decoding: {:?}", samples));
+            }
+            Msg::AudioDecodingFailed(err) => {
+                ConsoleService::error(&format!("Error decoding: {:?}", err));
+            }
+            _ => (),
         };
     }
 
@@ -51,6 +82,7 @@ impl Agent for AudioAgent {
 
 impl AudioAgent {
     fn load_samples_from_file(&mut self, file: File) -> Result<(), String> {
+        self.bytes_buffer = Vec::with_capacity(file.size() as usize);
         let cb = self.link.callback(Msg::FileProgress);
 
         let task = self
@@ -63,14 +95,19 @@ impl AudioAgent {
         Ok(())
     }
 
-    fn handle_file_progress(&mut self, chunk: FileChunk) -> Result<(), String> {
-        match chunk {
-            FileChunk::Started { name, .. } => ConsoleService::log(&format!("Started: {}", name)),
-            FileChunk::DataChunk { progress, .. } => {
-                ConsoleService::log(&format!("Got chunk, progress: {}", progress))
-            }
-            FileChunk::Finished => ConsoleService::log("Finished"),
-        }
+    fn handle_file_progress(&mut self, mut data: Vec<u8>, _progress: f32) -> Result<(), String> {
+        self.bytes_buffer.append(&mut data);
         Ok(())
     }
+
+    fn handle_file_loaded(&self) -> Result<(), String> {
+        let audio_data = Uint8Array::from(&self.bytes_buffer[..]);
+        match self.audio_context.decode_audio_data(&audio_data.buffer()) {
+            Ok(promise) => {
+                self.link.send_future(JsFuture::from(promise));
+                Ok(())
+            }
+            Err(e) => Err(format!("Error from decode_audio_data: {:?}", e)),
+        }
+    }
 }