minor improvements to background audio & window modules

src/background/audio.ts

@@ -3,6 +3,7 @@
 "use strict";
 
 import { sendAudio } from './session'
+import { ipcMain } from "electron";
 const portAudio = require('naudiodon');
 
 let ai: typeof portAudio.AudioIO;
@@ -17,39 +18,39 @@ const audioOptions = {
     closeOnError: false,
 }
 
-// run every time the main function launches.
-export const initAudioIO = () => {
-  // init portAudio readable stream once.
-  if (!ai) {
-    ai = new portAudio.AudioIO({ inOptions: audioOptions });
+// main function run by run.ts module.
+export function initAudioIO(): void {
+    // init portAudio readable stream once.
+    if (!ai) {
+        ai = new portAudio.AudioIO({ inOptions: audioOptions });
 
-    // base64 encoding needed for google speech to text.
-    ai.setEncoding(encoding);
+        // base64 encoding needed for google speech to text.
+        ai.setEncoding(encoding);
 
-    // pause the portAudio data flow as soon as stream is initiated.
-    ai.start();
-    ai.pause();
+        // pause the portAudio data flow as soon as stream is initiated.
+        ai.start();
+        ai.pause();
 
-    ai.on('error', (e: Error) => {
-      console.log('Error recording audio', + e);
-    });
-    ai.on('data', (chunk: string) => {
-      // turn string base64 data into buffer object.
-      console.log('received string chunk of length', chunk.length)
-      const buf = Buffer.from(chunk, encoding);
-      audioInput.push(buf);
-    });
-  }
+        ai.on('error', (e: Error) => {
+            console.log('Error recording audio', + e);
+        });
+        ai.on('data', (chunk: string) => {
+            // turn string base64 data into buffer object.
+            console.log('received string chunk of length', chunk.length)
+            const buf = Buffer.from(chunk, encoding);
+            audioInput.push(buf);
+        });
+    }
 
-  // init portAudio writable stream once.
-  if (!ao) {
-      ao = new portAudio.AudioIO({ outOptions: audioOptions });
-      ao.start();
-  }
+    // init portAudio writable stream once.
+    if (!ao) {
+        ao = new portAudio.AudioIO({ outOptions: audioOptions });
+        ao.start();
+    }
 }
 
 // run this function on space bar key up and down.
-export const updateRecorder = (_event, record: boolean): void => {
+const updateRecorder = (_event, record: boolean): void => {
     if (record) {
         // resume mic data flow on space bar key down.
         ai.resume();
@@ -58,12 +59,17 @@ export const updateRecorder = (_event, record: boolean): void => {
         ai.pause();
         const audio = Buffer.concat(audioInput);
         sendAudio(audio);
-        audioInput = [];
+        // clear audioInput.
+        while(audioInput.length) { audioInput.pop()}
     }
 }
 
+// listen for space key up/down event. 
+ipcMain.removeAllListeners('update-recorder');
+ipcMain.on('update-recorder', updateRecorder);
+
 // play audio buffers.
-export const play = (input: Array<Buffer>) => {
+export function play(input: Array<Buffer>): void {
     let i = 0;
     // format buffers into half their size to account for writable highwaterMark.
     const audio = bufSplit(input);
@@ -76,6 +82,7 @@ export const play = (input: Array<Buffer>) => {
     function write() {
         let chunk: Buffer;
         let ok = true;
+
         do {
             chunk = audio[i];
             if (i === audio.length - 1) {
@@ -96,7 +103,7 @@ export const play = (input: Array<Buffer>) => {
     }
 }
 
-// utility function used by play func
+// utility function used by play func.
 function bufSplit(input: Array<Buffer>): Array<Buffer> {
     let result: Buffer[] = [];
     input.forEach((b: Buffer) => {

src/background/window.ts

@@ -3,7 +3,6 @@
 import { BrowserWindow, ipcMain } from "electron";
 import { createProtocol } from "vue-cli-plugin-electron-builder/lib";
 import { backgroundMitt } from './emitter';
-import { updateRecorder } from './audio';
 import * as path from "path";
 
 interface WindowSettings {
@@ -28,31 +27,48 @@ interface IpcRendererPayload {
 
 let win: BrowserWindow | null;
 
+// Util function to handle window close & minimize.
+const navBarHandler = (_event, action: string): void => {
+    switch(action) {
+        case 'close':
+            if (win) win.close();
+        break;
+        case 'min':
+            if (win) win.minimize();
+        break;
+    }
+}
+
+// Util function to render message on ipc-renderer event.
+const renderMessage = (payload: IpcRendererPayload): void => {
+    if (win) {
+        win.webContents.send(payload.endpoint, {
+            message: payload.message
+        });
+    }
+}
+
+// Do this on window mount.
 const windowMount = (): void => {
-  backgroundMitt.emit('window-active', true);
-  ipcMain.removeAllListeners('update-recorder');
-  ipcMain.on('update-recorder', updateRecorder);
-  // handle renderer auth-token event
-  ipcMain.removeHandler('nav-bar'); // avoid setting duplicate handlers
-  ipcMain.handle('nav-bar', navBarHandler);
+    backgroundMitt.emit('window-active', true);
+    // handle win nav-bar event.
+    ipcMain.removeHandler('nav-bar'); // avoid setting duplicate handlers
+    ipcMain.handle('nav-bar', navBarHandler);
+    // render messages through ipc-renderer.
+    backgroundMitt.once('ipc-renderer', renderMessage);
 }
 
+// do this on window dismount.
 const windowDismount = (): void => {
-  win = null;
-  backgroundMitt.emit('window-active', false);
-  ipcMain.removeAllListeners('update-recorder');
+    win = null;
+    backgroundMitt.emit('window-active', false);
 }
 
-backgroundMitt.on('ipc-renderer', (payload: IpcRendererPayload) => {
-  if (win)
-    win.webContents.send(payload.endpoint, {
-      message: payload.message
-    });
-});
-
-export const createWindow = async (options: WindowSettings): Promise<void> => {
+// function used by run.ts to create the main window. 
+export async function createWindow(options: WindowSettings): Promise<void> {
   return new Promise((resolve, _reject) => {
 
+    // avoid creating duplicate windows.
     if (win) resolve();
 
     win = new BrowserWindow({
@@ -95,15 +111,3 @@ export const createWindow = async (options: WindowSettings): Promise<void> => {
 
   });
 };
-
-// call this function on nav bar click
-function navBarHandler(_event, action: string) {
-    switch(action) {
-        case 'close':
-            if (win) win.close();
-            break;
-        case 'min':
-            if (win) win.minimize();
-            break;
-    }
-}