Cashew: implement backend usage API

src/device.cc

 // Copyright (c) 2010 The Chromium OS Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/device.h"
 
 #include <glog/logging.h>
 
 #include "src/service.h"
 
@@ skipping 11 matching lines @@
 // Flimflam Device on-the-wire Type values
 static const char* kFlimflamDeviceTypeEthernet = "ethernet";
 static const char* kFlimflamDeviceTypeWifi = "wifi";
 static const char* kFlimflamDeviceTypeWimax = "wimax";
 static const char* kFlimflamDeviceTypeBluetooth = "bluetooth";
 static const char* kFlimflamDeviceTypeGPS = "gps";
 static const char* kFlimflamDeviceTypeCellular = "cellular";
 // TODO(vlaviano): what does vendor look like?
 static const char* kFlimflamDeviceTypeVendor = "";
 
-Device::Device(DBus::Connection& connection,  // NOLINT
+Device::Device(Service * const parent, DBus::Connection& connection,  // NOLINT
                const DBus::Path& path)
     : DBus::ObjectProxy(connection, path, kFlimflamDeviceName),
-      path_(path), type_(kTypeUnknown), carrier_(kCarrierUnknown) {
+      parent_(CHECK_NOTNULL(parent)), path_(path), type_(kTypeUnknown),
+      carrier_(kCarrierUnknown) {
   // init our state with a GetProperties() call to our Flimflam service path
   // we'll update this state by monitoring PropertyChanged signals
   GetDeviceProperties();
 }
 
 Device::~Device() {
 }
 
 const DBus::Path& Device::GetPath() const {
   return path_;
@@ skipping 42 matching lines @@
     return kTypeCellular;
   }
   if (type.compare(kFlimflamDeviceTypeVendor) == 0) {
     return kTypeVendor;
   }
   return kTypeUnknown;
 }
 
 void Device::OnCarrierUpdate(const std::string& carrier) {
   DLOG(INFO) << path_ << ": OnCarrierUpdate: carrier = " << carrier;
-  if (carrier_.compare(kCarrierUnknown) && carrier_.compare(carrier)) {
-    LOG(WARNING) << path_ << ": OnCarrierUpdate: carrier change from "
-        << carrier_ << " to " << carrier << "!";
+  // only propagate this to parent Service if there's been a change
+  // we expect to see only one such change (from "Unknown")
+  if (carrier_.compare(carrier)) {
+    if (carrier_.compare(kCarrierUnknown)) {
+      LOG(WARNING) << path_ << ": OnCarrierUpdate: carrier change from "
+          << carrier_ << " to " << carrier << "!";
+    }
+    carrier_ = carrier;
+    parent_->OnCarrierUpdate(carrier);
   }
-  // TODO(vlaviano): load backend module for this carrier if needed
-  carrier_ = carrier;
 }
 
 void Device::OnTypeUpdate(const std::string& type) {
   DLOG(INFO) << path_ << ": OnTypeUpdate: type = " << type;
   type_ = TypeFromString(type);
   if (type_ != kTypeCellular) {
     LOG(WARNING) << path_ << ": OnTypeUpdate: type is not cellular!";
   }
 }
 
@@ skipping 31 matching lines @@
   }
   // don't expect to find Cellular.* properties if we're not a cellular device
   if (type_ != kTypeCellular) {
     return;
   }
   it = properties.find(kFlimflamDeviceCarrierProperty);
   if (it != properties.end()) {
     const DBus::Variant& value = static_cast<DBus::Variant>(it->second);
     OnCarrierUpdate(value.reader().get_string());
   } else {
-    DLOG(WARNING) << path_ << ": GetDeviceProperties: no Carrier property";
+    DLOG(WARNING) << path_
+        << ": GetDeviceProperties: no Cellular.Carrier property";
   }
 }
 
 }  // namespace cashew