Added events endpoint to API

Author: devgianlu

api/src/main/java/xyz/gianlu/librespot/api/ApiServer.java

@@ -4,6 +4,7 @@
 import io.undertow.server.RoutingHandler;
 import org.apache.log4j.Logger;
 import org.jetbrains.annotations.NotNull;
+import xyz.gianlu.librespot.api.handlers.EventsHandler;
 import xyz.gianlu.librespot.api.handlers.MetadataHandler;
 import xyz.gianlu.librespot.api.handlers.PlayerHandler;
 import xyz.gianlu.librespot.core.Session;
@@ -23,7 +24,8 @@ public ApiServer(int port) {
 
     private static void prepareHandlers(@NotNull RoutingHandler root, @NotNull Session session) {
         root.post("/player/{cmd}", new PlayerHandler(session))
-                .post("/metadata/{type}/{uri}", new MetadataHandler(session));
+                .post("/metadata/{type}/{uri}", new MetadataHandler(session))
+                .get("/events", new EventsHandler(session));
     }
 
     public void start(@NotNull Session session) {

api/src/main/java/xyz/gianlu/librespot/api/handlers/EventsHandler.java

@@ -0,0 +1,61 @@
+package xyz.gianlu.librespot.api.handlers;
+
+import com.google.gson.JsonObject;
+import com.spotify.metadata.proto.Metadata;
+import io.undertow.websockets.WebSocketConnectionCallback;
+import io.undertow.websockets.WebSocketProtocolHandshakeHandler;
+import io.undertow.websockets.core.WebSocketChannel;
+import io.undertow.websockets.core.WebSockets;
+import org.apache.log4j.Logger;
+import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
+import xyz.gianlu.librespot.common.ProtobufToJson;
+import xyz.gianlu.librespot.core.Session;
+import xyz.gianlu.librespot.mercury.model.PlayableId;
+import xyz.gianlu.librespot.player.Player;
+
+public class EventsHandler extends WebSocketProtocolHandshakeHandler implements Player.EventsListener {
+    private static final Logger LOGGER = Logger.getLogger(EventsHandler.class);
+
+    public EventsHandler(@NotNull Session session) {
+        super((WebSocketConnectionCallback) (exchange, channel) -> LOGGER.info(String.format("Accepted new websocket connection from %s.", channel.getSourceAddress().getAddress())));
+        session.player().addEventsListener(this);
+    }
+
+    private void dispatch(@NotNull JsonObject obj) {
+        for (WebSocketChannel channel : getPeerConnections())
+            WebSockets.sendText(obj.toString(), channel, null);
+    }
+
+    @Override
+    public void onContextChanged(@NotNull String newUri) {
+        JsonObject obj = new JsonObject();
+        obj.addProperty("event", "contextChanged");
+        obj.addProperty("uri", newUri);
+        dispatch(obj);
+    }
+
+    @Override
+    public void onTrackChanged(@NotNull PlayableId id, Metadata.@Nullable Track track, Metadata.@Nullable Episode episode) {
+        JsonObject obj = new JsonObject();
+        obj.addProperty("event", "trackChanged");
+        obj.addProperty("uri", id.toSpotifyUri());
+        if (track != null) obj.add("track", ProtobufToJson.convert(track));
+        if (episode != null) obj.add("episode", ProtobufToJson.convert(episode));
+        dispatch(obj);
+    }
+
+    @Override
+    public void onPlaybackPaused() {
+        JsonObject obj = new JsonObject();
+        obj.addProperty("event", "playbackPaused");
+        dispatch(obj);
+    }
+
+    @Override
+    public void onPlaybackResumed() {
+        JsonObject obj = new JsonObject();
+        obj.addProperty("event", "playbackResumed");
+        dispatch(obj);
+    }
+}

core/src/main/java/xyz/gianlu/librespot/player/Player.java

@@ -694,7 +694,7 @@ public interface Configuration {
         int releaseLineDelay();
     }
 
-    private interface EventsListener {
+    public interface EventsListener {
         void onContextChanged(@NotNull String newUri);
 
         void onTrackChanged(@NotNull PlayableId id, @Nullable Metadata.Track track, @Nullable Metadata.Episode episode);