Add listener for "reaction" signaling message

Signed-off-by: Daniel Calviño Sánchez <danxuliu@gmail.com>

app/src/main/java/com/nextcloud/talk/activities/CallActivity.java

@@ -2805,6 +2805,10 @@ public class CallActivity extends CallBaseActivity {
             }
         }
 
+        @Override
+        public void onReaction(String reaction) {
+        }
+
         @Override
         public void onUnshareScreen() {
             endPeerConnection(sessionId, "screen");

app/src/main/java/com/nextcloud/talk/call/CallParticipant.java

@@ -40,6 +40,10 @@ public class CallParticipant {
             callParticipantModel.setRaisedHand(state, timestamp);
         }
 
+        @Override
+        public void onReaction(String reaction) {
+        }
+
         @Override
         public void onUnshareScreen() {
         }

app/src/main/java/com/nextcloud/talk/models/json/signaling/NCMessagePayload.kt

@@ -42,8 +42,10 @@ data class NCMessagePayload(
     @JsonField(name = ["state"])
     var state: Boolean? = null,
     @JsonField(name = ["timestamp"])
-    var timestamp: Long? = null
+    var timestamp: Long? = null,
+    @JsonField(name = ["reaction"])
+    var reaction: String? = null
 ) : Parcelable {
     // This constructor is added to work with the 'com.bluelinelabs.logansquare.annotation.JsonObject'
-    constructor() : this(null, null, null, null, null, null, null)
+    constructor() : this(null, null, null, null, null, null, null, null)
 }

app/src/main/java/com/nextcloud/talk/signaling/CallParticipantMessageNotifier.java

@@ -93,6 +93,12 @@ class CallParticipantMessageNotifier {
         }
     }
 
+    public void notifyReaction(String sessionId, String reaction) {
+        for (SignalingMessageReceiver.CallParticipantMessageListener listener : getListenersFor(sessionId)) {
+            listener.onReaction(reaction);
+        }
+    }
+
     public synchronized void notifyUnshareScreen(String sessionId) {
         for (SignalingMessageReceiver.CallParticipantMessageListener listener : getListenersFor(sessionId)) {
             listener.onUnshareScreen();

app/src/main/java/com/nextcloud/talk/signaling/SignalingMessageReceiver.java

@@ -149,6 +149,7 @@ public abstract class SignalingMessageReceiver {
      */
     public interface CallParticipantMessageListener {
         void onRaiseHand(boolean state, long timestamp);
+        void onReaction(String reaction);
         void onUnshareScreen();
     }
 
@@ -562,6 +563,57 @@ public abstract class SignalingMessageReceiver {
             return;
         }
 
+        if ("reaction".equals(type)) {
+            // Message schema (external signaling server):
+            // {
+            //     "type": "message",
+            //     "message": {
+            //         "sender": {
+            //             ...
+            //         },
+            //         "data": {
+            //             "to": #STRING#,
+            //             "roomType": "video",
+            //             "type": "reaction",
+            //             "payload": {
+            //                 "reaction": #STRING#,
+            //             },
+            //             "from": #STRING#,
+            //         },
+            //     },
+            // }
+            //
+            // Message schema (internal signaling server):
+            // {
+            //     "type": "message",
+            //     "data": {
+            //         "to": #STRING#,
+            //         "roomType": "video",
+            //         "type": "reaction",
+            //         "payload": {
+            //             "reaction": #STRING#,
+            //         },
+            //         "from": #STRING#,
+            //     },
+            // }
+
+            NCMessagePayload payload = signalingMessage.getPayload();
+            if (payload == null) {
+                // Broken message, this should not happen.
+                return;
+            }
+
+            String reaction = payload.getReaction();
+            if (reaction == null) {
+                // Broken message, this should not happen.
+                return;
+            }
+
+            callParticipantMessageNotifier.notifyReaction(sessionId, reaction);
+
+            return;
+        }
+
         // "unshareScreen" messages are directly sent to the screen peer connection when the internal signaling
         // server is used, and to the room when the external signaling server is used. However, the (relevant) data
         // of the received message ("from" and "type") is the same in both cases.

app/src/test/java/com/nextcloud/talk/signaling/SignalingMessageReceiverCallParticipantTest.java

@@ -84,6 +84,26 @@ public class SignalingMessageReceiverCallParticipantTest {
         verify(mockedCallParticipantMessageListener, only()).onRaiseHand(true, 4815162342L);
     }
 
+    @Test
+    public void testCallParticipantMessageReaction() {
+        SignalingMessageReceiver.CallParticipantMessageListener mockedCallParticipantMessageListener =
+            mock(SignalingMessageReceiver.CallParticipantMessageListener.class);
+
+        signalingMessageReceiver.addListener(mockedCallParticipantMessageListener, "theSessionId");
+
+        NCSignalingMessage signalingMessage = new NCSignalingMessage();
+        signalingMessage.setFrom("theSessionId");
+        signalingMessage.setType("reaction");
+        signalingMessage.setRoomType("theRoomType");
+        NCMessagePayload messagePayload = new NCMessagePayload();
+        messagePayload.setType("reaction");
+        messagePayload.setReaction("theReaction");
+        signalingMessage.setPayload(messagePayload);
+        signalingMessageReceiver.processSignalingMessage(signalingMessage);
+
+        verify(mockedCallParticipantMessageListener, only()).onReaction("theReaction");
+    }
+
     @Test
     public void testCallParticipantMessageUnshareScreen() {
         SignalingMessageReceiver.CallParticipantMessageListener mockedCallParticipantMessageListener =