Move sound into browser

src/browser/services/Services.d.ts

@@ -72,3 +72,7 @@ export interface ISelectionService {
   refresh(isLinuxMouseSelection?: boolean): void;
   onMouseDown(event: MouseEvent): void;
 }
+
+export interface ISoundService {
+  playBellSound(): void;
+}

src/browser/services/SoundService.ts

@@ -0,0 +1,61 @@
+/**
+ * Copyright (c) 2018 The xterm.js authors. All rights reserved.
+ * @license MIT
+ */
+
+import { IOptionsService } from 'common/services/Services';
+import { ISoundService } from 'browser/services/Services';
+
+export class SoundService implements ISoundService {
+  private static _audioContext: AudioContext;
+
+  static get audioContext(): AudioContext | null {
+    if (!SoundService._audioContext) {
+      const audioContextCtor: typeof AudioContext = (<any>window).AudioContext || (<any>window).webkitAudioContext;
+      if (!audioContextCtor) {
+        console.warn('Web Audio API is not supported by this browser. Consider upgrading to the latest version');
+        return null;
+      }
+      SoundService._audioContext = new audioContextCtor();
+    }
+    return SoundService._audioContext;
+  }
+
+  constructor(
+    private _optionsService: IOptionsService
+  ) {
+  }
+
+  public playBellSound(): void {
+    const ctx = SoundService.audioContext;
+    if (!ctx) {
+      return;
+    }
+    const bellAudioSource = ctx.createBufferSource();
+    ctx.decodeAudioData(this._base64ToArrayBuffer(this._removeMimeType(this._optionsService.options.bellSound)), (buffer) => {
+      bellAudioSource.buffer = buffer;
+      bellAudioSource.connect(ctx.destination);
+      bellAudioSource.start(0);
+    });
+  }
+
+  private _base64ToArrayBuffer(base64: string): ArrayBuffer {
+    const binaryString = window.atob(base64);
+    const len = binaryString.length;
+    const bytes = new Uint8Array(len);
+
+    for (let i = 0; i < len; i++) {
+      bytes[i] = binaryString.charCodeAt(i);
+    }
+
+    return bytes.buffer;
+  }
+
+  private _removeMimeType(dataURI: string): string {
+    // Split the input to get the mime-type and the data itself
+    const splitUri = dataURI.split(',');
+
+    // Return only the data
+    return splitUri[1];
+  }
+}