From 85aa3b3f83d9412aaf4dc7dffb07fdfff789e7fa Mon Sep 17 00:00:00 2001
From: Brad Hefta-Gaub <brad@highfidelity.io>
Date: Tue, 17 Nov 2015 14:28:51 -0800
Subject: [PATCH] handle subscribe when messages mixer is not available

---
 examples/example/messagesExample.js         | 40 ++++++++++-----------
 examples/example/messagesReceiverExample.js | 20 ++---------
 libraries/networking/src/MessagesClient.cpp | 16 ++++-----
 libraries/networking/src/MessagesClient.h   |  5 ++-
 4 files changed, 33 insertions(+), 48 deletions(-)

diff --git a/examples/example/messagesExample.js b/examples/example/messagesExample.js
index f5d8dea2d3..390549a135 100644
--- a/examples/example/messagesExample.js
+++ b/examples/example/messagesExample.js
@@ -12,29 +12,25 @@ Script.update.connect(function (deltaTime) {
         subscribedForTime += deltaTime;
     }
 
-    if (totalTime > 5) {
-
-        // if we've been unsubscribed for SWITCH_SUBSCRIPTION_TIME seconds, subscribe
-        if (!subscribed && unsubscribedForTime > SWITCH_SUBSCRIPTION_TIME) {
-            print("---- subscribing ----");
-            Messages.subscribe(channel);
-            subscribed = true;
-            subscribedForTime = 0;
-        }
-
-        // if we've been subscribed for SWITCH_SUBSCRIPTION_TIME seconds, unsubscribe
-        if (subscribed && subscribedForTime > SWITCH_SUBSCRIPTION_TIME) {
-            print("---- unsubscribing ----");
-            Messages.unsubscribe(channel);
-            subscribed = false;
-            unsubscribedForTime = 0;
-        }
-
-        // Even if not subscribed, still publish
-        var message = "update() deltaTime:" + deltaTime;
-        //print(message);
-        Messages.sendMessage(channel, message);
+    // if we've been unsubscribed for SWITCH_SUBSCRIPTION_TIME seconds, subscribe
+    if (!subscribed && unsubscribedForTime > SWITCH_SUBSCRIPTION_TIME) {
+        print("---- subscribing ----");
+        Messages.subscribe(channel);
+        subscribed = true;
+        subscribedForTime = 0;
     }
+
+    // if we've been subscribed for SWITCH_SUBSCRIPTION_TIME seconds, unsubscribe
+    if (subscribed && subscribedForTime > SWITCH_SUBSCRIPTION_TIME) {
+        print("---- unsubscribing ----");
+        Messages.unsubscribe(channel);
+        subscribed = false;
+        unsubscribedForTime = 0;
+    }
+
+    // Even if not subscribed, still publish
+    var message = "update() deltaTime:" + deltaTime;
+    Messages.sendMessage(channel, message);
 });
 
 
diff --git a/examples/example/messagesReceiverExample.js b/examples/example/messagesReceiverExample.js
index caab270783..2239ab1fc3 100644
--- a/examples/example/messagesReceiverExample.js
+++ b/examples/example/messagesReceiverExample.js
@@ -1,21 +1,7 @@
-var totalTime = 0;
-var subscribed = false;
-var WAIT_FOR_SUBSCRIPTION_TIME = 10;
-function myUpdate(deltaTime) {
-    var channel = "example";
-    totalTime += deltaTime;
-
-    if (totalTime > WAIT_FOR_SUBSCRIPTION_TIME && !subscribed) {
-
-        print("---- subscribing ----");
-        Messages.subscribe(channel);
-        subscribed = true;
-        Script.update.disconnect(myUpdate);
-    }
-}
-
-Script.update.connect(myUpdate);
+print("---- subscribing ----");
+Messages.subscribe(channel);
 
 Messages.messageReceived.connect(function (channel, message, senderID) {
     print("message received on channel:" + channel + ", message:" + message + ", senderID:" + senderID);
 });
+
diff --git a/libraries/networking/src/MessagesClient.cpp b/libraries/networking/src/MessagesClient.cpp
index 81e9c3abdf..88d64adcdd 100644
--- a/libraries/networking/src/MessagesClient.cpp
+++ b/libraries/networking/src/MessagesClient.cpp
@@ -27,7 +27,7 @@ MessagesClient::MessagesClient() {
     auto nodeList = DependencyManager::get<NodeList>();
     auto& packetReceiver = nodeList->getPacketReceiver();
     packetReceiver.registerMessageListener(PacketType::MessagesData, this, "handleMessagesPacket");
-    connect(nodeList.data(), &LimitedNodeList::nodeKilled, this, &MessagesClient::handleNodeKilled);
+    connect(nodeList.data(), &LimitedNodeList::nodeAdded, this, &MessagesClient::handleNodeAdded);
 }
 
 void MessagesClient::init() {
@@ -75,10 +75,8 @@ void MessagesClient::sendMessage(const QString& channel, const QString& message)
     }
 }
 
-// FIXME - we should keep track of the channels we are subscribed to locally, and
-// in the event that they mixer goes away and/or comes back we should automatically
-// resubscribe to those channels
 void MessagesClient::subscribe(const QString& channel) {
+    _subscribedChannels << channel;
     auto nodeList = DependencyManager::get<NodeList>();
     SharedNodePointer messagesMixer = nodeList->soloNodeOfType(NodeType::MessagesMixer);
 
@@ -90,6 +88,7 @@ void MessagesClient::subscribe(const QString& channel) {
 }
 
 void MessagesClient::unsubscribe(const QString& channel) {
+    _subscribedChannels.remove(channel);
     auto nodeList = DependencyManager::get<NodeList>();
     SharedNodePointer messagesMixer = nodeList->soloNodeOfType(NodeType::MessagesMixer);
 
@@ -100,9 +99,10 @@ void MessagesClient::unsubscribe(const QString& channel) {
     }
 }
 
-void MessagesClient::handleNodeKilled(SharedNodePointer node) {
-    if (node->getType() != NodeType::MessagesMixer) {
-        return;
+void MessagesClient::handleNodeAdded(SharedNodePointer node) {
+    if (node->getType() == NodeType::MessagesMixer) {
+        for (const auto& channel : _subscribedChannels) {
+            subscribe(channel);
+        }
     }
-    // FIXME - do we need to do any special bookkeeping for when the messages mixer is no longer available
 }
diff --git a/libraries/networking/src/MessagesClient.h b/libraries/networking/src/MessagesClient.h
index 4eb63c3e74..695e7e789e 100644
--- a/libraries/networking/src/MessagesClient.h
+++ b/libraries/networking/src/MessagesClient.h
@@ -37,7 +37,10 @@ signals:
 
 private slots:
     void handleMessagesPacket(QSharedPointer<NLPacketList> packetList, SharedNodePointer senderNode);
-    void handleNodeKilled(SharedNodePointer node);
+    void handleNodeAdded(SharedNodePointer node);
+
+protected:
+    QSet<QString> _subscribedChannels;
 };
 
 #endif