From 1c000a045bd8ee58e11231b4119c0e8d4cee9d55 Mon Sep 17 00:00:00 2001
From: Emil Axelsson <mail@emilaxelsson.se>
Date: Wed, 16 May 2018 12:47:06 +0200
Subject: [PATCH] Make it possible to unsubscribe to the time (#612)

---
 modules/server/include/timetopic.h      |  1 +
 modules/server/src/topics/timetopic.cpp | 11 ++++++++++-
 2 files changed, 11 insertions(+), 1 deletion(-)

diff --git a/modules/server/include/timetopic.h b/modules/server/include/timetopic.h
index 00d314984d..e3197d4916 100644
--- a/modules/server/include/timetopic.h
+++ b/modules/server/include/timetopic.h
@@ -41,6 +41,7 @@ private:
     nlohmann::json currentTime();
     nlohmann::json deltaTime();
 
+    bool _isDone;
     int _timeCallbackHandle;
     int _deltaTimeCallbackHandle;
     std::chrono::system_clock::time_point _lastUpdateTime;
diff --git a/modules/server/src/topics/timetopic.cpp b/modules/server/src/topics/timetopic.cpp
index 31f3a713a3..91c57b7783 100644
--- a/modules/server/src/topics/timetopic.cpp
+++ b/modules/server/src/topics/timetopic.cpp
@@ -31,6 +31,8 @@
 namespace {
 const char* _loggerCat = "TimeTopic";
 const char* PropertyKey = "property";
+const char* EventKey = "event";
+const char* UnsubscribeEvent = "stop_subscription";
 const char* CurrentTimeKey = "currentTime";
 const char* DeltaTimeKey = "deltaTime";
 const int UNSET_ONCHANGE_HANDLE = -1;
@@ -43,6 +45,7 @@ namespace openspace {
 
 TimeTopic::TimeTopic()
     : Topic()
+    , _isDone(false)
     , _timeCallbackHandle(UNSET_ONCHANGE_HANDLE)
     , _deltaTimeCallbackHandle(UNSET_ONCHANGE_HANDLE)
     , _lastUpdateTime(std::chrono::system_clock::now())
@@ -60,10 +63,15 @@ TimeTopic::~TimeTopic() {
 }
 
 bool TimeTopic::isDone() {
-    return false;
+    return _isDone;
 }
 
 void TimeTopic::handleJson(json j) {
+    std::string event = j.at(EventKey).get<std::string>();
+    if (event == UnsubscribeEvent) {
+        _isDone = true;
+        return;
+    }
 
     std::string requestedKey = j.at(PropertyKey).get<std::string>();
     LDEBUG("Subscribing to " + requestedKey);
@@ -92,6 +100,7 @@ void TimeTopic::handleJson(json j) {
     }
     else {
         LWARNING("Cannot get " + requestedKey);
+        _isDone = true;
     }
 }