Remove candidates when doing continual gathering

webrtc/examples/androidapp/src/org/appspot/apprtc/WebSocketRTCClient.java

 /*
  *  Copyright 2014 The WebRTC Project Authors. All rights reserved.
  *
  *  Use of this source code is governed by a BSD-style license
  *  that can be found in the LICENSE file in the root of the source
  *  tree. An additional intellectual property rights grant can be found
  *  in the file PATENTS.  All contributing project authors may
  *  be found in the AUTHORS file in the root of the source tree.
  */
 
 package org.appspot.apprtc;
 
 import org.appspot.apprtc.RoomParametersFetcher.RoomParametersFetcherEvents;
 import org.appspot.apprtc.WebSocketChannelClient.WebSocketChannelEvents;
 import org.appspot.apprtc.WebSocketChannelClient.WebSocketConnectionState;
 import org.appspot.apprtc.util.AsyncHttpURLConnection;
 import org.appspot.apprtc.util.AsyncHttpURLConnection.AsyncHttpEvents;
 import org.appspot.apprtc.util.LooperExecutor;
 
 import android.util.Log;
 
+import org.json.JSONArray;
 import org.json.JSONException;
 import org.json.JSONObject;
 import org.webrtc.IceCandidate;
 import org.webrtc.SessionDescription;
 
 /**
  * Negotiates signaling for chatting with apprtc.appspot.com "rooms".
  * Uses the client<->server specifics of the apprtc AppEngine webapp.
  *
  * <p>To use: create an instance of this object (registering a message handler) and
@@ skipping 213 matching lines @@
             events.onRemoteIceCandidate(candidate);
           }
         } else {
           // Call receiver sends ice candidates to websocket server.
           wsClient.send(json.toString());
         }
       }
     });
   }
 
+  // Send removed Ice candidates to the other participant.
+  @Override
+  public void sendLocalIceCandidateRemovals(final IceCandidate[] candidates) {
+    executor.execute(new Runnable() {
+      @Override
+      public void run() {
+        JSONObject json = new JSONObject();
+        jsonPut(json, "type", "remove-candidates");
+        JSONArray jsonArray =  new JSONArray();
+        for (final IceCandidate candidate : candidates) {
+          jsonArray.put(toJsonCandidate(candidate));
+        }
+        jsonPut(json, "candidates", jsonArray);
+        if (initiator) {
+          // Call initiator sends ice candidates to GAE server.
+          if (roomState != ConnectionState.CONNECTED) {
+            reportError("Sending ICE candidate removals in non connected state.");
+            return;
+          }
+          sendPostMessage(MessageType.MESSAGE, messageUrl, json.toString());
+          if (connectionParameters.loopback) {
+            events.onRemoteIceCandidatesRemoved(candidates);
+          }
+        } else {
+          // Call receiver sends ice candidates to websocket server.
+          wsClient.send(json.toString());
+        }
+      }
+    });
+  }
+
   // --------------------------------------------------------------------
   // WebSocketChannelEvents interface implementation.
   // All events are called by WebSocketChannelClient on a local looper thread
   // (passed to WebSocket client constructor).
   @Override
   public void onWebSocketMessage(final String msg) {
     if (wsClient.getState() != WebSocketConnectionState.REGISTERED) {
       Log.e(TAG, "Got WebSocket message in non registered state.");
       return;
     }
     try {
       JSONObject json = new JSONObject(msg);
       String msgText = json.getString("msg");
       String errorText = json.optString("error");
       if (msgText.length() > 0) {
         json = new JSONObject(msgText);
         String type = json.optString("type");
         if (type.equals("candidate")) {
-          IceCandidate candidate = new IceCandidate(
-              json.getString("id"),
-              json.getInt("label"),
-              json.getString("candidate"));
-          events.onRemoteIceCandidate(candidate);
+          events.onRemoteIceCandidate(toJavaCandidate(json));
+        } else if (type.equals("remove-candidates")) {
+          JSONArray candidateArray = json.getJSONArray("candidates");
+          IceCandidate[] candidates = new IceCandidate[candidateArray.length()];
+          for (int i =0; i < candidateArray.length(); ++i) {
+            candidates[i] = toJavaCandidate(candidateArray.getJSONObject(i));
+          }
+          events.onRemoteIceCandidatesRemoved(candidates);
         } else if (type.equals("answer")) {
           if (initiator) {
             SessionDescription sdp = new SessionDescription(
                 SessionDescription.Type.fromCanonicalForm(type),
                 json.getString("sdp"));
             events.onRemoteDescription(sdp);
           } else {
             reportError("Received answer for call initiator: " + msg);
           }
         } else if (type.equals("offer")) {
@@ skipping 81 matching lines @@
                 reportError("GAE POST error: " + result);
               }
             } catch (JSONException e) {
               reportError("GAE POST JSON error: " + e.toString());
             }
           }
         }
       });
     httpConnection.send();
   }
+
+  // Converts a Java candidate to a JSONObject.
+  private JSONObject toJsonCandidate(final IceCandidate candidate) {
+    JSONObject json = new JSONObject();
+    jsonPut(json, "label", candidate.sdpMLineIndex);
+    jsonPut(json, "id", candidate.sdpMid);
+    jsonPut(json, "candidate", candidate.sdp);
+    return json;
+  }
+
+  // Converts a JSON candidate to a Java object.
+  IceCandidate toJavaCandidate(JSONObject json) throws JSONException {
+    return new IceCandidate(json.getString("id"),
+                            json.getInt("label"),
+                            json.getString("candidate"));
+  }
 }