From d9e72db5ccc7592785c3d5eb6b4c6300c4d12127 Mon Sep 17 00:00:00 2001
From: Joshua Bell <inexorabletash@gmail.com>
Date: Wed, 25 Nov 2015 10:21:53 -0800
Subject: [PATCH] Rework bell hook

---
 index.js | 19 ++++++++++++-------
 tty.js   | 11 +++--------
 2 files changed, 15 insertions(+), 15 deletions(-)

diff --git a/index.js b/index.js
index 9cb87e1..1585f0c 100644
--- a/index.js
+++ b/index.js
@@ -5,12 +5,6 @@ window.addEventListener('DOMContentLoaded', function () {
 
   $('#lb_files').selectedIndex = 0;
 
-  var bell = (function () {
-    var b = new Bell(/^.*\/|/.exec(window.location)[0]);
-    return function () { b.play(); };
-  } ());
-
-
   var frame = $('#frame');
 
   var keyboard = frame;
@@ -26,7 +20,18 @@ window.addEventListener('DOMContentLoaded', function () {
     frame.parentNode.insertBefore(keyboard, frame);
   }
 
-  var tty = new TTY($('#screen'), keyboard, bell);
+  var tty = new TTY($('#screen'), keyboard);
+  (function() {
+    // Install output hook for bell
+    var b = new Bell(/^.*\/|/.exec(window.location)[0]);
+    var orig = tty.writeChar;
+    tty.writeChar = function index_writeChar(c) {
+      if (c.charCodeAt(0) === 7)
+        b.play();
+      else
+        orig(c);
+    };
+  }());
   var dos = new DOS(tty);
 
   var lores = new LoRes($('#lores'), 40, 48);
diff --git a/tty.js b/tty.js
index 62d8965..8858657 100644
--- a/tty.js
+++ b/tty.js
@@ -4,7 +4,7 @@
 
 // Usage:
 //
-//   tty = new TTY( screen_element, keyboard_element, bell );
+//   tty = new TTY( screen_element, keyboard_element );
 //   tty.clearScreen()
 //   tty.clearEOL()
 //   tty.clearEOS()
@@ -34,7 +34,7 @@
 //   tty.TEXT_STYLE_INVERSE = 1
 //   tty.TEXT_STYLE_FLASH   = 2
 
-function TTY(screenElement, keyboardElement, bell) {
+function TTY(screenElement, keyboardElement) {
 
   // Constants
 
@@ -348,15 +348,10 @@ function TTY(screenElement, keyboardElement, bell) {
       case 4: // DOS hook takes care of CHR$(4)
       case 5:
       case 6:
+      case 7: // (BEL) bell - handled by index hook
         // no-op
         break;
 
-      case 7: // (BEL) bell
-        if (bell) {
-          bell();
-        }
-        break;
-
       case 8: // (BS) backspace
         self.cursorLeft();
         break;