api,voice: new HoldAndAccept() method

This method will put the currently active call on hold, and right away
accept the next available call.

The user of the API does not need to specify explicitly which is the
next call to accept, because that is decided automatically:
  * If there is any waiting call, it will accept it right away.
  * If there is no waiting call but there is a held call, it will make
  the held call active again.

src/mm-iface-modem-voice.c

@@ -544,6 +544,148 @@ handle_list (MmGdbusModemVoice *skeleton,
 
 /*****************************************************************************/
 
+typedef struct {
+    MmGdbusModemVoice     *skeleton;
+    GDBusMethodInvocation *invocation;
+    MMIfaceModemVoice     *self;
+    GList                 *active_calls;
+    MMBaseCall            *next_call;
+} HandleHoldAndAcceptContext;
+
+static void
+handle_hold_and_accept_context_free (HandleHoldAndAcceptContext *ctx)
+{
+    g_list_free_full (ctx->active_calls, g_object_unref);
+    g_clear_object (&ctx->next_call);
+    g_object_unref (ctx->skeleton);
+    g_object_unref (ctx->invocation);
+    g_object_unref (ctx->self);
+    g_slice_free (HandleHoldAndAcceptContext, ctx);
+}
+
+static void
+hold_and_accept_ready (MMIfaceModemVoice          *self,
+                       GAsyncResult               *res,
+                       HandleHoldAndAcceptContext *ctx)
+{
+    GError *error = NULL;
+    GList  *l;
+
+    if (!MM_IFACE_MODEM_VOICE_GET_INTERFACE (self)->hold_and_accept_finish (self, res, &error)) {
+        g_dbus_method_invocation_take_error (ctx->invocation, error);
+        handle_hold_and_accept_context_free (ctx);
+        return;
+    }
+
+    for (l = ctx->active_calls; l; l = g_list_next (l))
+        mm_base_call_change_state (MM_BASE_CALL (l->data), MM_CALL_STATE_HELD, MM_CALL_STATE_REASON_UNKNOWN);
+    if (ctx->next_call)
+        mm_base_call_change_state (ctx->next_call, MM_CALL_STATE_ACTIVE, MM_CALL_STATE_REASON_ACCEPTED);
+
+    mm_gdbus_modem_voice_complete_hold_and_accept (ctx->skeleton, ctx->invocation);
+    handle_hold_and_accept_context_free (ctx);
+}
+
+static void
+prepare_hold_and_accept_foreach (MMBaseCall                 *call,
+                                 HandleHoldAndAcceptContext *ctx)
+{
+    switch (mm_base_call_get_state (call)) {
+    case MM_CALL_STATE_ACTIVE:
+        ctx->active_calls = g_list_append (ctx->active_calls, g_object_ref (call));
+        break;
+    case MM_CALL_STATE_WAITING:
+        g_clear_object (&ctx->next_call);
+        ctx->next_call = g_object_ref (call);
+        break;
+    case MM_CALL_STATE_HELD:
+        if (!ctx->next_call)
+            ctx->next_call = g_object_ref (call);
+        break;
+    default:
+        break;
+    }
+}
+
+static void
+handle_hold_and_accept_auth_ready (MMBaseModem                *self,
+                                   GAsyncResult               *res,
+                                   HandleHoldAndAcceptContext *ctx)
+{
+    MMModemState  modem_state = MM_MODEM_STATE_UNKNOWN;
+    GError       *error = NULL;
+    MMCallList   *list = NULL;
+
+    if (!mm_base_modem_authorize_finish (self, res, &error)) {
+        g_dbus_method_invocation_take_error (ctx->invocation, error);
+        handle_hold_and_accept_context_free (ctx);
+        return;
+    }
+
+    g_object_get (self,
+                  MM_IFACE_MODEM_STATE, &modem_state,
+                  NULL);
+
+    if (modem_state < MM_MODEM_STATE_ENABLED) {
+        g_dbus_method_invocation_return_error (ctx->invocation,
+                                               MM_CORE_ERROR,
+                                               MM_CORE_ERROR_WRONG_STATE,
+                                               "Cannot hold and accept: device not yet enabled");
+        handle_hold_and_accept_context_free (ctx);
+        return;
+    }
+
+    if (!MM_IFACE_MODEM_VOICE_GET_INTERFACE (self)->hold_and_accept ||
+        !MM_IFACE_MODEM_VOICE_GET_INTERFACE (self)->hold_and_accept_finish) {
+        g_dbus_method_invocation_return_error (ctx->invocation,
+                                               MM_CORE_ERROR,
+                                               MM_CORE_ERROR_UNSUPPORTED,
+                                               "Cannot hold and accept: unsupported");
+        handle_hold_and_accept_context_free (ctx);
+        return;
+    }
+
+    g_object_get (self,
+                  MM_IFACE_MODEM_VOICE_CALL_LIST, &list,
+                  NULL);
+    if (!list) {
+        g_dbus_method_invocation_return_error (ctx->invocation,
+                                               MM_CORE_ERROR,
+                                               MM_CORE_ERROR_WRONG_STATE,
+                                               "Cannot hold and accept: missing call list");
+        handle_hold_and_accept_context_free (ctx);
+        return;
+    }
+    mm_call_list_foreach (list, (MMCallListForeachFunc)prepare_hold_and_accept_foreach, ctx);
+    g_object_unref (list);
+
+    MM_IFACE_MODEM_VOICE_GET_INTERFACE (self)->hold_and_accept (MM_IFACE_MODEM_VOICE (self),
+                                                                (GAsyncReadyCallback)hold_and_accept_ready,
+                                                                ctx);
+}
+
+static gboolean
+handle_hold_and_accept (MmGdbusModemVoice     *skeleton,
+                        GDBusMethodInvocation *invocation,
+                        MMIfaceModemVoice     *self)
+{
+    HandleHoldAndAcceptContext *ctx;
+
+    ctx = g_slice_new0 (HandleHoldAndAcceptContext);
+    ctx->skeleton   = g_object_ref (skeleton);
+    ctx->invocation = g_object_ref (invocation);
+    ctx->self       = g_object_ref (self);
+
+    mm_base_modem_authorize (MM_BASE_MODEM (self),
+                             invocation,
+                             MM_AUTHORIZATION_VOICE,
+                             (GAsyncReadyCallback)handle_hold_and_accept_auth_ready,
+                             ctx);
+    return TRUE;
+}
+
+/*****************************************************************************/
+
 typedef struct {
     MmGdbusModemVoice     *skeleton;
     GDBusMethodInvocation *invocation;
@@ -1370,6 +1512,10 @@ interface_initialization_step (GTask *task)
                           "handle-hangup-and-accept",
                           G_CALLBACK (handle_hangup_and_accept),
                           self);
+        g_signal_connect (ctx->skeleton,
+                          "handle-hold-and-accept",
+                          G_CALLBACK (handle_hold_and_accept),
+                          self);
 
         /* Finally, export the new interface */
         mm_gdbus_object_skeleton_set_modem_voice (MM_GDBUS_OBJECT_SKELETON (self),

src/mm-iface-modem-voice.h

@@ -92,6 +92,14 @@ struct _MMIfaceModemVoice {
                                   MMCallDirection    direction,
                                   const gchar       *number);
 
+    /* Hold and accept */
+    void     (* hold_and_accept)        (MMIfaceModemVoice    *self,
+                                         GAsyncReadyCallback   callback,
+                                         gpointer              user_data);
+    gboolean (* hold_and_accept_finish) (MMIfaceModemVoice    *self,
+                                         GAsyncResult         *res,
+                                         GError              **error);
+
     /* Hangup and accept */
     void     (* hangup_and_accept)        (MMIfaceModemVoice    *self,
                                            GAsyncReadyCallback   callback,