Merge pull request #7320 from evelynhung/issue-826112

Bug 826112 - record connected device by using asyncStorage

apps/settings/index.html

@@ -38,8 +38,11 @@
     <link rel="resource" type="application/l10n" href="locales/locales.ini"/>
     <script type="application/javascript" src="shared/js/l10n.js"></script>
     <script type="application/javascript" src="shared/js/l10n_date.js"></script>
+
+    <!-- shared helper library -->
     <script type="application/javascript" defer src="shared/js/mouse_event_shim.js"></script>
     <script type="application/javascript" defer src="shared/js/manifest_helper.js"></script>
+    <script type="application/javascript" defer src="shared/js/async_storage.js"></script>
 
     <!-- Specific code -->
     <script type="application/javascript" defer src="js/utils.js"></script>

apps/settings/js/bluetooth.js

@@ -349,11 +349,22 @@ onLocalized(function bluetoothSettings() {
         }
       );
 
-      getPairedDevice();
+      // get paired device and restore connection
+      // if we have one device connected before.
+      getPairedDevice(restoreConnection);
       startDiscovery();
     }
 
-    function getPairedDevice() {
+    function restoreConnection() {
+      window.asyncStorage.getItem('device.connected', function(value) {
+        if(!value || !pairList.index[value]) 
+          return;
+        var device = pairList.index[value][0]; 
+        setDeviceConnect(device);
+      });
+    }
+
+    function getPairedDevice(callback) {
       if (!bluetooth.enabled || !defaultAdapter)
         return;
       var req = defaultAdapter.getPairedDevices();
@@ -399,6 +410,10 @@ onLocalized(function bluetoothSettings() {
         });
         gBluetoothInfoBlock.textContent = text;
         pairList.show(true);
+        // the callback function now is for restoring the connected device
+        // when the bluetooth is turned on.
+        if (callback)
+          callback();
       };
     }
 
@@ -520,9 +535,14 @@ onLocalized(function bluetoothSettings() {
     function showDeviceConnected(deviceAddress, connected) {
       if (connected) {
         connectedAddress = deviceAddress;
+        // record connected device so if Bluetooth is turned off and then on
+        // we can restore the connection
+        window.asyncStorage.setItem('device.connected', connectedAddress);
       } else {
-        if (connectedAddress === deviceAddress)
+        if (connectedAddress === deviceAddress) {
           connectedAddress = null;
+          window.asyncStorage.removeItem('device.connected');
+        }
       }
       var item = pairList.index[deviceAddress][1];
       item.querySelector('small').textContent = (connected) ?