chrome.bluetoothLowEnergy: Implement getCharacteristic.

chrome/browser/extensions/api/bluetooth_low_energy/bluetooth_low_energy_api.cc

 // Copyright 2014 The Chromium 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 "chrome/browser/extensions/api/bluetooth_low_energy/bluetooth_low_energy_api.h"
 
 #include "base/bind.h"
 #include "base/lazy_instance.h"
 #include "base/strings/stringprintf.h"
 #include "chrome/browser/extensions/api/bluetooth_low_energy/bluetooth_low_energy_event_router.h"
 #include "chrome/common/extensions/api/bluetooth_low_energy.h"
 #include "content/public/browser/browser_thread.h"
 #include "extensions/browser/event_router.h"
 
 using content::BrowserContext;
 using content::BrowserThread;
 
 namespace apibtle = extensions::api::bluetooth_low_energy;
 
 namespace {
 
 const char kErrorAdapterNotInitialized[] =
     "Could not initialize Bluetooth adapter.";
+const char kErrorCharacteristicNotFoundFormat[] =
+    "Characteristic with ID \"%s\" not found.";
 const char kErrorDeviceNotFoundFormat[] =
     "Device with address \"%s\" not found.";
 const char kErrorServiceNotFoundFormat[] = "Service with ID \"%s\" not found.";
 const char kErrorPlatformNotSupported[] =
     "This operation is not supported on the current platform";
 
 extensions::BluetoothLowEnergyEventRouter* GetEventRouter(
     BrowserContext* context) {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
   return extensions::BluetoothLowEnergyAPI::Get(context)->event_router();
@@ skipping 156 matching lines @@
     return false;
   }
 
   results_ = apibtle::GetServices::Results::Create(service_list);
   SendResponse(true);
 
   return true;
 }
 
 bool BluetoothLowEnergyGetCharacteristicFunction::DoWork() {
-  // TODO(armansito): Implement.
-  SetError("Call not supported.");
-  SendResponse(false);
-  return false;
+  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
+
+  BluetoothLowEnergyEventRouter* event_router =
+      GetEventRouter(browser_context());
+
+  // The adapter must be initialized at this point, but return an error instead
+  // of asserting.
+  if (!event_router->HasAdapter()) {
+    SetError(kErrorAdapterNotInitialized);
+    SendResponse(false);
+    return false;
+  }
+
+  scoped_ptr<apibtle::GetCharacteristic::Params> params(
+      apibtle::GetCharacteristic::Params::Create(*args_));
+  EXTENSION_FUNCTION_VALIDATE(params.get() != NULL);
+
+  std::string characteristic_id = params->characteristic_id;
+
+  apibtle::Characteristic characteristic;
+  if (!event_router->GetCharacteristic(characteristic_id, &characteristic)) {
+    SetError(base::StringPrintf(kErrorCharacteristicNotFoundFormat,
+                                characteristic_id.c_str()));
+    SendResponse(false);
+    return false;
+  }
+
+  // Manually construct the result instead of using
+  // apibtle::GetCharacteristic::Result::Create as it doesn't convert lists of
+  // enums correctly.
+  SetResult(CharacteristicToValue(&characteristic).release());

[rpaquay, 2014/05/05 16:07:48]

Wasn't this bug was recently fixed? (crbug/ 368368)

[armansito, 2014/05/05 17:39:32]

No, it's still a problem. There is a CL that does fix it but it hasn't been
merged yet (https://codereview.chromium.org/260893013/).

+  SendResponse(true);
+
+  return true;
 }
 
 bool BluetoothLowEnergyGetCharacteristicsFunction::DoWork() {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
 
   BluetoothLowEnergyEventRouter* event_router =
       GetEventRouter(browser_context());
 
   // The adapter must be initialized at this point, but return an error instead
   // of asserting.
@@ skipping 105 matching lines @@
 
 bool BluetoothLowEnergyWriteDescriptorValueFunction::DoWork() {
   // TODO(armansito): Implement.
   SetError("Call not supported.");
   SendResponse(false);
   return false;
 }
 
 }  // namespace api
 }  // namespace extensions