Issue 2040 - Replaced localStorage with chrome.storage.local

lib/prefs.js

Index: lib/prefs.js
===================================================================
--- a/lib/prefs.js
+++ b/lib/prefs.js
@@ -15,12 +15,13 @@
  * along with Adblock Plus.  If not, see <http://www.gnu.org/licenses/>.
  */
 
-//
-// The values are hardcoded for now.
-//
+const keyPrefix = "pref:";
 
 let defaults = Object.create(null);
+let overrides = Object.create(null);
+
 defaults.enabled = true;
+defaults.currentVersion = "";
 defaults.data_directory = "";
 defaults.patternsbackups = 5;
 defaults.patternsbackupinterval = 24;
@@ -40,70 +41,112 @@
 defaults.shouldShowBlockElementMenu = true;
 defaults.hidePlaceholders = true;
 
-let listeners = [];
+let Prefs = exports.Prefs = {
+  onChanged: new ext._EventTarget(),
+  onLoaded: new ext._EventTarget()
+};
 
-function defineProperty(key)
+function keyToPref(key)
 {
-  let value = null;
-  Object.defineProperty(Prefs, key, {
+  if (key.indexOf(keyPrefix) != 0)
+    return null;
+
+  return key.substr(keyPrefix.length);
+}
+
+function prefToKey(pref)
+{
+  return keyPrefix + pref;
+}
+
+function addPreference(pref)
+{
+  Object.defineProperty(Prefs, pref, {
     get: function()
     {
-      if (value === null)
-      {
-        if (key in ext.storage)
-        {
-          try
-          {
-            value = JSON.parse(ext.storage[key]);
-          }
-          catch(e)
-          {
-            Cu.reportError(e);
-          }
-        }
+      return (pref in overrides ? overrides : defaults)[pref];
+    },
+    set: function(value)
+    {
+      let defaultValue = defaults[pref];
 
-        if (value === null)
-          value = JSON.parse(JSON.stringify(defaults[key]));
-      }
-      return value;
-    },
-    set: function(newValue)
-    {
-      if (typeof newValue != typeof defaults[key])
+      if (typeof value != typeof defaultValue)
         throw new Error("Attempt to change preference type");
 
-      let stringified = JSON.stringify(newValue);
-      if (stringified != JSON.stringify(defaults[key]))
-        ext.storage[key] = stringified;
+      if (value == defaultValue)
+      {
+        delete overrides[pref];
+        ext.storage.remove(prefToKey(pref));
+      }
       else
-        delete ext.storage[key];
-
-      value = newValue;
-
-      for (let listener of listeners)
-        listener(key);
-
-      return value;
+      {
+        overrides[pref] = value;
+        ext.storage.set(prefToKey(pref), value);
+      }
     },
     enumerable: true
   });
 }
 
+function init()
+{
+  let prefs = Object.keys(defaults);
+  prefs.forEach(addPreference);
 
-let Prefs = exports.Prefs = {
-  addListener: function(listener)
-  {
-    if (listeners.indexOf(listener) < 0)
-      listeners.push(listener);
-  },
+  // Migrate preferences for users updating from old versions.
+  // TODO: Remove the migration code after a few releases.
+  ext.storage.migratePrefs({
+    map: function(key, value)
+    {
+      if (key in defaults)
+      {
+        if (key != "currentVersion")
+        {
+          try
+          {
+            value = JSON.parse(value);
+          }
+          catch (e)
+          {
+            return null;
+          }
+        }
 
-  removeListener: function(listener)
-  {
-    let index = listeners.indexOf(listener);
-    if (index >= 0)
-      listeners.splice(index, 1);
-  },
-};
+        return {key: prefToKey(key), value: value};
+      }
 
-for (let key in defaults)
-  defineProperty(key);
+      return null;
+    },
+
+    done: function()
+    {
+      ext.storage.get(prefs.map(prefToKey), function(items)
+      {
+        for (let key in items)
+          overrides[keyToPref(key)] = items[key];
+
+        ext.storage.onChanged.addListener(function(changes)
+        {
+          for (let key in changes)
+          {
+            let pref = keyToPref(key);
+            if (pref && pref in defaults)
+            {
+              let change = changes[key];
+              if ("newValue" in change && change.newValue != defaults[pref])
+                overrides[pref] = change.newValue;
+              else
+                delete overrides[pref];
+
+              Prefs.onChanged._dispatch(pref);
+            }
+          }
+        });
+
+        Prefs.onLoaded._dispatch();
+      });
+    }
+  });
+}
+
+init();