cros: DBUS client to interact with fingerprint DBUS API.

chromeos/dbus/biod_biometrics_manager_client.h

+// Copyright 2017 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 CHROMEOS_DBUS_BIOD_BIOMETRICS_MANAGER_CLIENT_H_
+#define CHROMEOS_DBUS_BIOD_BIOMETRICS_MANAGER_CLIENT_H_
+
+#include <stdint.h>
+
+#include <unordered_map>
+#include <vector>
+
+#include "base/callback.h"
+#include "base/macros.h"
+#include "base/observer_list.h"
+#include "chromeos/chromeos_export.h"
+#include "chromeos/dbus/dbus_client.h"
+#include "chromeos/dbus/dbus_client_implementation_type.h"
+#include "chromeos/dbus/dbus_method_call_status.h"
+#include "third_party/cros_system_api/dbus/service_constants.h"
+
+namespace chromeos {
+
+// Each time the sensor detects a scan, an object containing all the users, each
+// with the labels of all the matched stored fingerprints is returned.
+using AuthScanMatches =
+    std::unordered_map<std::string, std::vector<std::string>>;
+
+// BiodBiometricsManagerClient is used to communicate with the biod dbus

[Daniel Erat, 2017/03/27 18:18:26]

nit: D-Bus

[sammiequon, 2017/03/27 23:21:49]

Done.

+// interface.
+class CHROMEOS_EXPORT BiodBiometricsManagerClient : public DBusClient {
+ public:
+  // Interface for observing changes from the biometrics.
+  class Observer {
+   public:
+    // Called when biometrics manager powers up or is restarted.
+    virtual void ClientRestarted() {}

[rkc, 2017/03/25 00:28:20]

This isn't the "client" that is restarting though, right? We are the client.
biod is the service.
Should this be ServiceRestarted instead?

[Daniel Erat, 2017/03/27 18:18:26]

well, biod and chrome are both d-bus clients... but i agree that this name is
confusing and that the method should be renamed to ServiceRestarted().

please also consider prefixing this method (and maybe all of the observer
methods) with "Biod". when a class implements multiple interfaces, it's
difficult to know which one an overridden method named "ServiceRestarted" is
coming from.

[sammiequon, 2017/03/27 23:21:48]

Done.

[sammiequon, 2017/03/27 23:21:49]

Done.

+
+    // Called whenever a user attempts a scan. |scan_result| tells whether the
+    // scan was succesful. |is_complete| tells whether enrollment is complete
+    // and now over.
+    virtual void EnrollScanDoneReceived(uint32_t scan_result,

[Daniel Erat, 2017/03/27 18:18:26]

at least from this comment, i have no idea what |scan_result| contains. is it an
enum that needs to be typecast?

[sammiequon, 2017/03/27 23:21:49]

Done.

+                                        bool is_complete) {}
+
+    // Called to indicate a bad scan of any kind, or a succesful scan. If scan

[Daniel Erat, 2017/03/27 18:18:26]

nit: successful

[sammiequon, 2017/03/27 23:21:48]

Done.

+    // is successful, |matches| will equal all the enrollment IDs that match the
+    // scan, and the labels of the matched fingeprints.
+    virtual void AuthScanDoneReceived(uint32_t scan_result,

[Daniel Erat, 2017/03/27 18:18:26]

as above, please document how to use |scan_result| (or better, use a type that
makes it obvious)

[sammiequon, 2017/03/27 23:21:49]

Done.

+                                      const AuthScanMatches& matches) {}
+
+    // Called during either session to indicate a failure. Any enrollment that
+    // was underway is thrown away and auth will no longer be happening.
+    virtual void SessionFailedReceived() {}
+
+   protected:
+    virtual ~Observer() {}
+  };
+
+  ~BiodBiometricsManagerClient() override;
+
+  // Adds and removes the observer.
+  virtual void AddObserver(Observer* observer) = 0;
+  virtual void RemoveObserver(Observer* observer) = 0;
+
+  // Returns true if this object has the given observer.
+  virtual bool HasObserver(const Observer* observer) const = 0;
+
+  // UserRecordsCallback is used for the GetRecordsForUser method. It receives
+  // one argument which contains a list of the stored records object paths for
+  // a given user.
+  using UserRecordsCallback =
+      base::Callback<void(const std::vector<dbus::ObjectPath>&)>;
+
+  // BiometricTypeCallback is used for the GetType method. It receives
+  // one argument which states the type of biometric.
+  using BiometricTypeCallback = base::Callback<void(biod::BiometricType)>;
+
+  // Starts the biometric enroll session. |callback| is called with the object
+  // path of the current enroll session after the method succeeds.
+  virtual void StartEnrollSession(const std::string& user_id,
+                                  const std::string& label,
+                                  const ObjectPathCallback& callback) = 0;
+
+  // Gets all the records registered with this biometric. |callback| is called
+  // with all the object paths of the records after this method succeeds.
+  virtual void GetRecordsForUser(const std::string& user_id,
+                                 const UserRecordsCallback& callback) = 0;
+
+  // Irreversibly destroys all records registered with this biometric.
+  virtual void DestroyAllRecords() = 0;
+
+  // Starts the biometric auth session. |callback| is called with the object
+  // path of the auth session after the method succeeds.
+  virtual void StartAuthSession(const ObjectPathCallback& callback) = 0;
+
+  // Requests the type of biometric. |callback| is called with the biometric
+  // type after the method succeeds.
+  virtual void RequestType(const BiometricTypeCallback& callback) = 0;
+
+  // Creates the instance.
+  static BiodBiometricsManagerClient* Create(DBusClientImplementationType type);
+
+ protected:
+  friend class BiodBiometricsManagerClientTest;
+
+  // Create() should be used instead.
+  BiodBiometricsManagerClient();
+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(BiodBiometricsManagerClient);
+};
+
+}  // namespace chromeos
+
+#endif  // CHROMEOS_DBUS_BIOD_BIOMETRICS_MANAGER_CLIENT_H_