Add Datachannel support to Android AppRTCMobile

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

Index: webrtc/examples/androidapp/src/org/appspot/apprtc/PeerConnectionClient.java
diff --git a/webrtc/examples/androidapp/src/org/appspot/apprtc/PeerConnectionClient.java b/webrtc/examples/androidapp/src/org/appspot/apprtc/PeerConnectionClient.java
index 8166b90adc2ee1be67e86a8d6bc1815f8ec4acfd..6052a4d8e3155e7fb7f1a621f447d4b7ee9ae77e 100644
--- a/webrtc/examples/androidapp/src/org/appspot/apprtc/PeerConnectionClient.java
+++ b/webrtc/examples/androidapp/src/org/appspot/apprtc/PeerConnectionClient.java
@@ -44,6 +44,7 @@ import org.webrtc.voiceengine.WebRtcAudioUtils;
 
 import java.io.File;
 import java.io.IOException;
+import java.nio.ByteBuffer;
 import java.util.Collections;
 import java.util.EnumSet;
 import java.util.LinkedList;
@@ -132,6 +133,31 @@ public class PeerConnectionClient {
   // enableAudio is set to true if audio should be sent.
   private boolean enableAudio;
   private AudioTrack localAudioTrack;
+  private DataChannel dataChannel;
+  private boolean dataChannelEnabled;
+
+  /**
+   * Peer connection parameters.
+   */
+  public static class DataChannelParameters {
+    public final boolean ordered;
+    public final int maxRetransmitTimeMs;
+    public final int maxRetransmits;
+    public final String protocol;
+    public final boolean negotiated;
+    public final int id;
+
+    public DataChannelParameters(
+            boolean ordered, int maxRetransmitTimeMs, int maxRetransmits, String protocol,
+            boolean negotiated, int id) {
+      this.ordered = ordered;
+      this.maxRetransmitTimeMs = maxRetransmitTimeMs;
+      this.maxRetransmits = maxRetransmits;
+      this.protocol = protocol;
+      this.negotiated = negotiated;
+      this.id = id;
+    }
+  }
 
   /**
    * Peer connection parameters.
@@ -155,12 +181,25 @@ public class PeerConnectionClient {
     public final boolean disableBuiltInAGC;
     public final boolean disableBuiltInNS;
     public final boolean enableLevelControl;
+    private final DataChannelParameters dataChannelParameters;
 
     public PeerConnectionParameters(boolean videoCallEnabled, boolean loopback, boolean tracing,
         int videoWidth, int videoHeight, int videoFps, int videoMaxBitrate, String videoCodec,
         boolean videoCodecHwAcceleration, int audioStartBitrate, String audioCodec,
         boolean noAudioProcessing, boolean aecDump, boolean useOpenSLES, boolean disableBuiltInAEC,
         boolean disableBuiltInAGC, boolean disableBuiltInNS, boolean enableLevelControl) {
+      this(videoCallEnabled, loopback, tracing, useCamera2, videoWidth, videoHeight, videoFps,
+      videoMaxBitrate, videoCodec, videoCodecHwAcceleration, audioStartBitrate,
+      audioCodec, noAudioProcessing, aecDump, useOpenSLES, disableBuiltInAEC, disableBuiltInAGC,
+      disableBuiltInNS, enableLevelControl, null);
+    }
+
+    public PeerConnectionParameters(boolean videoCallEnabled, boolean loopback, boolean tracing,
+        int videoWidth, int videoHeight, int videoFps, int videoMaxBitrate, String videoCodec,
+        boolean videoCodecHwAcceleration, int audioStartBitrate, String audioCodec,
+        boolean noAudioProcessing, boolean aecDump, boolean useOpenSLES, boolean disableBuiltInAEC,
+        boolean disableBuiltInAGC, boolean disableBuiltInNS, boolean enableLevelControl,
+        DataChannelParameters dataChannelParameters) {
       this.videoCallEnabled = videoCallEnabled;
       this.loopback = loopback;
       this.tracing = tracing;
@@ -179,6 +218,7 @@ public class PeerConnectionClient {
       this.disableBuiltInAGC = disableBuiltInAGC;
       this.disableBuiltInNS = disableBuiltInNS;
       this.enableLevelControl = enableLevelControl;
+      this.dataChannelParameters = dataChannelParameters;
     }
   }
 
@@ -249,6 +289,7 @@ public class PeerConnectionClient {
     this.peerConnectionParameters = peerConnectionParameters;
     this.events = events;
     videoCallEnabled = peerConnectionParameters.videoCallEnabled;
+    dataChannelEnabled = peerConnectionParameters.dataChannelParameters != null;
     // Reset variables to initial states.
     this.context = null;
     factory = null;
@@ -493,6 +534,17 @@ public class PeerConnectionClient {
     rtcConfig.keyType = PeerConnection.KeyType.ECDSA;
 
     peerConnection = factory.createPeerConnection(rtcConfig, pcConstraints, pcObserver);
+
+    if (dataChannelEnabled) {
+      DataChannel.Init init = new DataChannel.Init();
+      init.ordered = peerConnectionParameters.dataChannelParameters.ordered;
+      init.negotiated = peerConnectionParameters.dataChannelParameters.negotiated;
+      init.maxRetransmits = peerConnectionParameters.dataChannelParameters.maxRetransmits;
+      init.maxRetransmitTimeMs = peerConnectionParameters.dataChannelParameters.maxRetransmitTimeMs;
+      init.id = peerConnectionParameters.dataChannelParameters.id;
+      init.protocol = peerConnectionParameters.dataChannelParameters.protocol;
+      dataChannel = peerConnection.createDataChannel("ApprtcDemo data", init);
+    }
     isInitiator = false;
 
     // Set default WebRTC tracing and INFO libjingle logging.
@@ -533,6 +585,10 @@ public class PeerConnectionClient {
     }
     Log.d(TAG, "Closing peer connection.");
     statsTimer.cancel();
+    if (dataChannel != null) {
+      dataChannel.dispose();
+      dataChannel = null;
+    }
     if (peerConnection != null) {
       peerConnection.dispose();
       peerConnection = null;
@@ -549,6 +605,7 @@ public class PeerConnectionClient {
       } catch (InterruptedException e) {
         throw new RuntimeException(e);
       }
+      videoCapturerStopped = true;

[sakal, 2016/11/09 11:45:03]

This is probably correct but please do not add unrelated changes.

[hekra01, 2016/11/10 02:32:20]

Done.

       videoCapturer.dispose();
       videoCapturer = null;
     }
@@ -1084,7 +1141,43 @@ public class PeerConnectionClient {
 
     @Override
     public void onDataChannel(final DataChannel dc) {
-      reportError("AppRTC doesn't use data channels, but got: " + dc.label() + " anyway!");
+      Log.d(TAG, "NEW Data channel " + dc.label());

[sakal, 2016/11/09 11:45:03]

nit: Don't make new all caps

[hekra01, 2016/11/10 02:32:20]

Done.

+
+      if (!dataChannelEnabled)
+        return;
+
+      dc.registerObserver(new DataChannel.Observer() {
+        public void onBufferedAmountChange(long var1){

[sakal, 2016/11/09 11:45:03]

nit: var1 is not a very descriptive name here. Maybe it should also be logged?

How often is this callback triggered, does it spam the logs?

[hekra01, 2016/11/10 02:32:20]

Naming fixed
No spam.Callback doeas not seem called when tested 

+          Log.d(TAG,
+                  "Data channel buffered amount changed: " + dc.label() + ": " + dc.state());
+        }
+
+        @Override
+        public void onStateChange() {
+          Log.d(TAG,
+                  "Data channel state changed: " + dc.label() + ": " + dc.state());
+        }
+
+        @Override
+        public void onMessage(final DataChannel.Buffer buffer) {
+          if (buffer.binary) {
+            Log.d(TAG, "Received binary msg over " + dc);
+            return;
+          }
+          ByteBuffer data = buffer.data;
+          final byte[] bytes = new byte[ data.capacity() ];
+          data.get(bytes);
+          Runnable command = new Runnable() {
+            @Override
+            public void run() {
+              // Get DC message as String.
+              String strData = new String(bytes);
+              Log.d(TAG, "Got msg: " + strData + " over " + dc);

[sakal, 2016/11/09 11:45:03]

Maybe we should show the message in a toast?

[hekra01, 2016/11/10 02:32:20]

DataChannel use cases would be to enable chat/file transfer in addition to A/V.
This callback can be a starting point to do this later.
Currently , only toast would not be very useful for the end user, this is why I
only log at the moment.
Let me know if yo want toast all the same

+            }
+          };
+          executor.execute(command);

[sakal, 2016/11/09 11:45:03]

Why does this have to be posted?

[hekra01, 2016/11/10 02:32:20]

Done because of comments in the PeerConnectionClient constructor:
    // Executor thread is started once in private ctor and is used for all
    // peer connection API calls to ensure new peer connection factory is
    // created on the same thread as previously destroyed factory.

[sakal, 2016/11/10 08:31:42]

But you are not making any peerconnection API calls here?

[hekra01, 2016/11/10 14:16:53]

Correct. Removed the post

+        }
+      });
     }
 
     @Override