Add CallsAccountInterface

This interface should be implemented by origins which represent an online
account. This means they must have a implement a property representing the
credentials and another representing the account state (online, offline, etc).

src/calls-account.h

@@ -0,0 +1,70 @@
+/*
+ * Copyright (C) 2021 Purism SPC
+ *
+ * This file is part of Calls.
+ *
+ * Calls is free software: you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * Calls is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with Calls.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ * Author: Evangelos Ribeiro Tzaras <evangelos.tzaras@puri.sm>
+ *
+ * SPDX-License-Identifier: GPL-3.0-or-later
+ *
+ */
+
+#pragma once
+
+#include "calls-origin.h"
+
+#include <glib-object.h>
+
+G_BEGIN_DECLS
+
+
+#define CALLS_TYPE_ACCOUNT (calls_account_get_type ())
+
+G_DECLARE_INTERFACE (CallsAccount, calls_account, CALLS, ACCOUNT, CallsOrigin);
+
+
+struct _CallsAccountInterface
+{
+  GTypeInterface parent_iface;
+
+  void               (*go_online)                           (CallsAccount *self,
+                                                             gboolean      online);
+};
+/**
+ * CallsAccountState:
+ * @CALLS_ACCOUNT_NULL: Not initialized
+ * @CALLS_ACCOUNT_OFFLINE: Account considered offline (not ready for placing or receiving calls)
+ * @CALLS_ACCOUNT_CONNECTING: Trying to connect to server
+ * @CALLS_ACCOUNT_CONNECTION_FAILURE: Could not connect to server (f.e. DNS error, unreachable)
+ * @CALLS_ACCOUNT_AUTHENTICATING: Authenticating using web-auth/proxy-auth
+ * @CALLS_ACCOUNT_AUTHENTICATION_FAILURE: Could not authenticate to server (f.e. wrong credentials)
+ * @CALLS_ACCOUNT_ONLINE: Account considered online (can place and receive calls)
+ */
+typedef enum {
+  CALLS_ACCOUNT_NULL = 0,
+  CALLS_ACCOUNT_OFFLINE,
+  CALLS_ACCOUNT_CONNECTING,
+  CALLS_ACCOUNT_CONNECTION_FAILURE,
+  CALLS_ACCOUNT_AUTHENTICATING,
+  CALLS_ACCOUNT_AUTHENTICATION_FAILURE,
+  CALLS_ACCOUNT_ONLINE
+} CallsAccountState;
+
+
+void                   calls_account_go_online          (CallsAccount *self,
+                                                         gboolean      online);
+
+G_END_DECLS