Complete //device/bt implementation for hosting local GATT attributes.

device/bluetooth/dbus/bluetooth_gatt_descriptor_service_provider.h

 // 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.
 
 #ifndef DEVICE_BLUETOOTH_DBUS_BLUETOOTH_GATT_DESCRIPTOR_SERVICE_PROVIDER_H_
 #define DEVICE_BLUETOOTH_DBUS_BLUETOOTH_GATT_DESCRIPTOR_SERVICE_PROVIDER_H_
 
 #include <stdint.h>
-
 #include <string>
 #include <vector>
 
-#include "base/callback.h"
 #include "base/macros.h"
 #include "dbus/bus.h"
+#include "dbus/message.h"
 #include "dbus/object_path.h"
 #include "device/bluetooth/bluetooth_export.h"
+#include "device/bluetooth/bluez/bluetooth_gatt_service_bluez.h"
 
 namespace bluez {
 
 // BluetoothGattDescriptorServiceProvider is used to provide a D-Bus object that
 // represents a local GATT characteristic descriptor that the Bluetooth daemon
 // can communicate with.
 //
 // Instantiate with a chosen D-Bus object path, delegate, and other fields.
 // The Bluetooth daemon communicates with a GATT descriptor using the
 // standard DBus.Properties interface. While most properties of the GATT
 // descriptor interface are read-only and don't change throughout the
 // life-time of the object, the "Value" property is both writeable and its
 // value can change. Both Get and Set operations performed on the "Value"
 // property are delegated to the Delegate object, an instance of which is
 // mandatory during initialization. In addition, a "SendValueChanged" method is
 // provided, which emits a DBus.Properties.PropertyChanged signal for the
 // "Value" property.
 class DEVICE_BLUETOOTH_EXPORT BluetoothGattDescriptorServiceProvider {
  public:
-  // Interface for reacting to GATT characteristic descriptor value requests.
-  class Delegate {
-   public:
-    virtual ~Delegate() {}
-
-    // ValueCallback is used for methods that require a descriptor value
-    // to be returned.
-    typedef base::Callback<void(const std::vector<uint8_t>&)> ValueCallback;
-
-    // ErrorCallback is used by methods to report failure.
-    typedef base::Closure ErrorCallback;
-
-    // This method will be called when a remote device requests to read the
-    // value of the exported GATT descriptor. Invoke |callback| with a value
-    // to return that value to the requester. Invoke |error_callback| to report
-    // a failure to read the value. This can happen, for example, if the
-    // descriptor has no read permission set. Either callback should be
-    // invoked after a reasonable amount of time, since the request will time
-    // out if left pending for too long.
-    virtual void GetDescriptorValue(const ValueCallback& callback,
-                                    const ErrorCallback& error_callback) = 0;
-
-    // This method will be called, when a remote device requests to write the
-    // value of the exported GATT descriptor. Invoke |callback| to report
-    // that the value was successfully written. Invoke |error_callback| to
-    // report a failure to write the value. This can happen, for example, if the
-    // descriptor has no write permission set. Either callback should be
-    // invoked after a reasonable amount of time, since the request will time
-    // out if left pending for too long.
-    //
-    // The delegate should use this method to perform any side-effects that may
-    // occur based on the set value and potentially send a property changed
-    // signal to notify the Bluetooth daemon that the value has changed.
-    virtual void SetDescriptorValue(const std::vector<uint8_t>& value,
-                                    const base::Closure& callback,
-                                    const ErrorCallback& error_callback) = 0;
-  };
-
   virtual ~BluetoothGattDescriptorServiceProvider();
 
   // Send a PropertyChanged signal to notify the Bluetooth daemon that the value
   // of the "Value" property has changed to |value|.
   virtual void SendValueChanged(const std::vector<uint8_t>& value) = 0;
 
+  // Writes the descriptor's properties into the provided writer. If
+  // value is not null, it is written also, otherwise no value property is
+  // written.
+  virtual void WriteProperties(dbus::MessageWriter* writer,
+                               const std::vector<uint8_t>* value) {}
+
+  virtual const dbus::ObjectPath& object_path() const = 0;
+
   // Creates the instance, where |bus| is the D-Bus bus connection to export
   // the object onto, |uuid| is the 128-bit GATT descriptor UUID, |permissions|
   // is the list of attribute permissions, |characteristic_path| is the object
   // path of the exported GATT characteristic the descriptor belongs to,
   // |object_path| is the object path that the descriptor should have, and
   // |delegate| is the object that value Get/Set requests will be passed to and
   // responses generated from.
   //
   // Object paths of GATT descriptors must be hierarchical to the path of the
   // GATT characteristic they belong to. Hence, |object_path| must have
   // |characteristic_path| as its prefix. Ownership of |delegate| is not taken,
   // thus the delegate should outlive this instance. A delegate should handle
   // only a single exported descriptor and own it.
   static BluetoothGattDescriptorServiceProvider* Create(
       dbus::Bus* bus,
       const dbus::ObjectPath& object_path,
-      Delegate* delegate,
+      BluetoothGattServiceBlueZ::AttributeValueDelegate* delegate,
       const std::string& uuid,
       const std::vector<std::string>& permissions,
       const dbus::ObjectPath& characteristic_path);
 
  protected:
   BluetoothGattDescriptorServiceProvider();
 
  private:
   DISALLOW_COPY_AND_ASSIGN(BluetoothGattDescriptorServiceProvider);
 };
 
 }  // namespace bluez
 
 #endif  // DEVICE_BLUETOOTH_DBUS_BLUETOOTH_GATT_DESCRIPTOR_SERVICE_PROVIDER_H_