libmm-glib,nmea: new method to get list of traces

Fixes https://gitlab.freedesktop.org/mobile-broadband/ModemManager/issues/120

docs/reference/libmm-glib/libmm-glib-sections.txt

@@ -528,6 +528,7 @@ mm_location_3gpp_get_type
 MMLocationGpsNmea
 <SUBSECTION Getters>
 mm_location_gps_nmea_get_trace
+mm_location_gps_nmea_get_traces
 mm_location_gps_nmea_build_full
 <SUBSECTION Private>
 mm_location_gps_nmea_new

libmm-glib/mm-location-gps-nmea.c

@@ -152,6 +152,42 @@ mm_location_gps_nmea_get_trace (MMLocationGpsNmea *self,
 
 /*****************************************************************************/
 
+static void
+build_all_foreach (const gchar  *trace_type,
+                   const gchar  *trace,
+                   GPtrArray   **built)
+{
+    if (*built == NULL)
+        *built = g_ptr_array_new ();
+    g_ptr_array_add (*built, g_strdup (trace));
+}
+
+/**
+ * mm_location_gps_nmea_get_traces:
+ * @self: a #MMLocationGpsNmea.
+ *
+ * Gets all cached traces.
+ *
+ * Returns: (transfer full): The list of traces, or %NULL if none available. The returned value should be freed with g_strfreev().
+ * Since: 1.14
+ */
+gchar **
+mm_location_gps_nmea_get_traces (MMLocationGpsNmea *self)
+{
+    GPtrArray *built = NULL;
+
+    g_hash_table_foreach (self->priv->traces,
+                          (GHFunc)build_all_foreach,
+                          &built);
+    if (!built)
+        return NULL;
+
+    g_ptr_array_add (built, NULL);
+    return (gchar **) g_ptr_array_free (built, FALSE);
+}
+
+/*****************************************************************************/
+
 static void
 build_full_foreach (const gchar *trace_type,
                     const gchar *trace,

libmm-glib/mm-location-gps-nmea.h

@@ -59,9 +59,10 @@ GType mm_location_gps_nmea_get_type (void);
 G_DEFINE_AUTOPTR_CLEANUP_FUNC (MMLocationGpsNmea, g_object_unref)
 #endif
 
-const gchar *mm_location_gps_nmea_get_trace (MMLocationGpsNmea *self,
-                                             const gchar *trace_type);
-gchar *mm_location_gps_nmea_build_full (MMLocationGpsNmea *self);
+const gchar  *mm_location_gps_nmea_get_trace  (MMLocationGpsNmea *self,
+                                               const gchar       *trace_type);
+gchar       **mm_location_gps_nmea_get_traces (MMLocationGpsNmea *self);
+gchar        *mm_location_gps_nmea_build_full (MMLocationGpsNmea *self);
 
 /*****************************************************************************/
 /* ModemManager/libmm-glib/mmcli specific methods */