Update audioplayers impl:

Emit error if set source fails to set ready state
Implement new release method
Return NULL in align with audioplayers API

Author: DoumanAsh

src/plugins/audioplayers.h

@@ -47,4 +47,6 @@ const char* audio_player_subscribe_channel_name(const struct audio_player *self)
 ///Returns `true` if player uses `channel`, otherwise returns `false
 bool audio_player_set_subscription_status(struct audio_player *self, const char *channel, bool value);
 
+void audio_player_release(struct audio_player *self);
+
 #endif  // AUDIOPLAYERS_H_

src/plugins/audioplayers/player.c

@@ -210,6 +210,7 @@ gboolean audio_player_on_bus_message(GstBus *bus, GstMessage *message, struct au
         case GST_MESSAGE_ASYNC_DONE:
             if (!data->is_seek_completed) {
                 audio_player_on_seek_completed(data);
+                data->is_seek_completed = true;
             }
             break;
         default:
@@ -291,13 +292,13 @@ void audio_player_on_media_state_change(struct audio_player *self, GstObject *sr
     if (streq(GST_OBJECT_NAME(src), "playbin")) {
         LOG_DEBUG("%s: on_media_state_change(old_state=%d, new_state=%d)\n", self->player_id, *old_state, *new_state);
         if (*new_state == GST_STATE_READY) {
-            self->is_initialized = false;
-
             // Need to set to pause state, in order to make player functional
             GstStateChangeReturn ret = gst_element_set_state(self->playbin, GST_STATE_PAUSED);
             if (ret == GST_STATE_CHANGE_FAILURE) {
                 LOG_ERROR("Unable to set the pipeline to the paused state.\n");
             }
+
+            self->is_initialized = false;
         } else if (*old_state == GST_STATE_PAUSED && *new_state == GST_STATE_PLAYING) {
             audio_player_on_position_update(self);
             audio_player_on_duration_update(self);
@@ -558,7 +559,10 @@ void audio_player_set_source_url(struct audio_player *self, char *url) {
         if (strlen(self->url) != 0) {
             g_object_set(self->playbin, "uri", self->url, NULL);
             if (self->playbin->current_state != GST_STATE_READY) {
-                gst_element_set_state(self->playbin, GST_STATE_READY);
+                if (gst_element_set_state(self->playbin, GST_STATE_READY) == GST_STATE_CHANGE_FAILURE) {
+                    //This should not happen generally
+                    LOG_ERROR("Could not set player into ready state.\n");
+                }
             }
         }
     } else {
@@ -582,3 +586,19 @@ bool audio_player_set_subscription_status(struct audio_player *self, const char
         return false;
     }
 }
+
+void audio_player_release(struct audio_player *self) {
+    self->is_initialized = false;
+    self->is_playing = false;
+    if (self->url != NULL) {
+        free(self->url);
+        self->url = NULL;
+    }
+
+    GstState playbinState;
+    gst_element_get_state(self->playbin, &playbinState, NULL, GST_CLOCK_TIME_NONE);
+
+    if (playbinState > GST_STATE_NULL) {
+        gst_element_set_state(self->playbin, GST_STATE_NULL);
+    }
+}

src/plugins/audioplayers/plugin.c

@@ -31,7 +31,7 @@ static int on_local_method_call(char *channel, struct platch_obj *object, Flutte
     struct std_value *args, *tmp;
     const char *method;
     char *player_id, *mode;
-    int result = 1;
+    struct std_value result = STDNULL;
     int ok;
 
     (void) responsehandle;
@@ -75,8 +75,7 @@ static int on_local_method_call(char *channel, struct platch_obj *object, Flutte
         audio_player_pause(player);
         audio_player_set_position(player, 0);
     } else if (streq(method, "release")) {
-        audio_player_pause(player);
-        audio_player_set_position(player, 0);
+        audio_player_release(player);
     } else if (streq(method, "seek")) {
         tmp = stdmap_get_str(args, "position");
         if (tmp == NULL || !STDVALUE_IS_INT(*tmp)) {
@@ -109,7 +108,7 @@ static int on_local_method_call(char *channel, struct platch_obj *object, Flutte
 
         audio_player_set_source_url(player, url);
     } else if (streq(method, "getDuration")) {
-        result = audio_player_get_duration(player);
+        result = STDINT64(audio_player_get_duration(player));
     } else if (streq(method, "setVolume")) {
         tmp = stdmap_get_str(args, "volume");
         if (tmp != NULL && STDVALUE_IS_FLOAT(*tmp)) {
@@ -118,7 +117,7 @@ static int on_local_method_call(char *channel, struct platch_obj *object, Flutte
             return platch_respond_illegal_arg_std(responsehandle, "Expected `arg['volume']` to be a float.");
         }
     } else if (streq(method, "getCurrentPosition")) {
-        result = audio_player_get_position(player);
+        result = STDINT64(audio_player_get_position(player));
     } else if (streq(method, "setPlaybackRate")) {
         tmp = stdmap_get_str(args, "playbackRate");
         if (tmp != NULL && STDVALUE_IS_FLOAT(*tmp)) {
@@ -191,7 +190,7 @@ static int on_local_method_call(char *channel, struct platch_obj *object, Flutte
         return platch_respond_not_implemented(responsehandle);
     }
 
-    return platch_respond_success_std(responsehandle, &STDINT64(result));
+    return platch_respond_success_std(responsehandle, &result);
 }
 
 static int on_global_method_call(char *channel, struct platch_obj *object, FlutterPlatformMessageResponseHandle *responsehandle) {