add onerror support for MozSettings emulation and remove hack from ke…

…yboard.js

apps/homescreen/js/keyboard.js

@@ -32,41 +32,18 @@ const IMEManager = {
     'zhuying': ['zh-Hant-Zhuying']
   },
 
-  kMozSettingsTimeout: 800,
   loadKeyboardSettings: function loadKeyboardSettings(callback) {
-    var completed = false;
     var completeSettingRequests = (function completeSettingRequests() {
-
-      if (completed)
-        return;
-
-      clearTimeout(settingTimer);
-
-      if (!this.keyboards.length)
-        this.keyboards =
-          [].concat(
-            this.keyboardSettingGroups['english'],
-            this.keyboardSettingGroups['zhuying']
-          );
-
       if (this.keyboards.indexOf(this.currentKeyboard) === -1)
         this.currentKeyboard = this.keyboards[0];
 
       this.keyboards.forEach((function loadIMEngines(name) {
         this.loadKeyboard(name);
       }).bind(this));
 
-      completed = true;
       callback();
     }).bind(this);
 
-    // XXX: Fallback if MozSettings timed out
-    var settingTimer = setTimeout(function () {
-      dump('Keyboard: MozSettings timed out. Skip user settings.');
-      completeSettingRequests();
-
-    }, this.kMozSettingsTimeout);
-
     this.keyboards = [];
     var keyboardSettingGroupKeys = [];
     for (var key in this.keyboardSettingGroups) {

webapi.js

@@ -247,20 +247,34 @@
   navigator.mozSettings = {
     get: function(key) {
       var onsuccess = [];
+      var onerror = [];
       var request = {
         addEventListener: function(name, fn) {
-          if (name === "success")
+          if (name === 'success')
             onsuccess.push(fn);
+          if (name === 'error')
+            onerror.push(fn);
         },
         set onsuccess(fn) {
           onsuccess.push(fn);
         },
+        set onerror(fn) {
+          onerror.push(fn);
+        }
       };
       setImmediate(function() {
-        request.result = {
-          key: key,
-          value: localStorage.getItem(prefix + key)
-        };
+        try {
+          request.result = {
+            key: key,
+            value: localStorage.getItem(prefix + key)
+          };
+        } catch (e) {
+          while (onerror.length > 0) {
+            var fn = onerror.shift();
+            fn();
+          }
+          return;
+        }
         while (onsuccess.length > 0) {
           var fn = onsuccess.shift();
           fn();