Added Options Page

Added Options Page allowing user to customize shortcuts and other
parameters

options.js

@@ -0,0 +1,107 @@
+function recordKeyPress(e) {
+  var normalizedKeyCode = String.fromCharCode(e.keyCode).toUpperCase().charCodeAt();
+  e.target.value = getInputMsg(normalizedKeyCode);
+  e.target.keyCode = normalizedKeyCode;
+  
+  e.preventDefault();
+  e.stopPropagation();
+};
+
+function inputFocus(e) {
+   e.target.value = "";
+};
+
+function inputBlur(e) {
+   e.target.value = getInputMsg(e.target.keyCode);
+};
+
+function updateShortcutInputText(inputId, keyCode) {
+  document.getElementById(inputId).value = getInputMsg(keyCode);
+  document.getElementById(inputId).keyCode = keyCode;
+}
+
+function getInputMsg(keyCode) {
+  return "Shortcut set to " + String.fromCharCode(keyCode).toUpperCase(); 
+};
+
+// Saves options to chrome.storage
+function save_options() {
+ 
+  var speedStep     = Number(document.getElementById('speedStep').value);
+  var rewindTime    = document.getElementById('rewindTime').value;
+  var rewindKeyCode = document.getElementById('rewindKeyInput').keyCode;
+  var slowerKeyCode = document.getElementById('slowerKeyInput').keyCode;
+  var fasterKeyCode = document.getElementById('fasterKeyInput').keyCode;
+  
+  rewindTime    = isNaN(rewindTime) ? 10 : rewindTime;
+  rewindKeyCode = isNaN(rewindKeyCode) ? 65 : rewindKeyCode;
+  slowerKeyCode = isNaN(slowerKeyCode) ? 83 : slowerKeyCode;
+  fasterKeyCode = isNaN(fasterKeyCode) ? 68 : fasterKeyCode;
+
+  chrome.storage.sync.set({
+    speedStep:      speedStep,
+    rewindTime:     rewindTime,
+    rewindKeyCode:  rewindKeyCode,
+    slowerKeyCode:  slowerKeyCode,
+    fasterKeyCode:  fasterKeyCode
+  }, function() {
+    // Update status to let user know options were saved.
+    var status = document.getElementById('status');
+    status.textContent = 'Options saved';
+    setTimeout(function() {
+      status.textContent = '';
+    }, 1000);
+  });
+}
+
+// Restores options from chrome.storage
+function restore_options() {
+  chrome.storage.sync.get({
+    speedStep: 0.25,
+    rewindTime: 10,
+    rewindKeyCode: 65,
+    slowerKeyCode: 83,
+    fasterKeyCode: 68
+  }, function(storage) {
+    document.getElementById('speedStep').value = storage.speedStep.toFixed(2);
+    document.getElementById('rewindTime').value = storage.rewindTime;
+    updateShortcutInputText('rewindKeyInput', storage.rewindKeyCode);
+    updateShortcutInputText('slowerKeyInput', storage.slowerKeyCode);
+    updateShortcutInputText('fasterKeyInput', storage.fasterKeyCode);
+  });
+}
+
+function restore_defaults() {
+  
+  chrome.storage.sync.set({
+    speedStep: 0.25,
+    rewindTime: 10,
+    rewindKeyCode: 65,
+    slowerKeyCode: 83,
+    fasterKeyCode: 68
+  }, function() {
+    restore_options();
+    // Update status to let user know options were saved.
+    var status = document.getElementById('status');
+    status.textContent = 'Default options restored';
+    setTimeout(function() {
+      status.textContent = '';
+    }, 1000);
+  });
+  
+}
+
+// Event Listeners
+document.addEventListener('DOMContentLoaded', restore_options);
+document.getElementById('save').addEventListener('click', save_options);
+document.getElementById('restore').addEventListener('click', restore_defaults);
+
+initShortcutInput('rewindKeyInput');
+initShortcutInput('slowerKeyInput');
+initShortcutInput('fasterKeyInput');
+
+function initShortcutInput(inputId) {
+  document.getElementById(inputId).addEventListener('focus', inputFocus);
+  document.getElementById(inputId).addEventListener('blur', inputBlur);
+  document.getElementById(inputId).addEventListener('keypress', recordKeyPress);
+}