Added json broadcasting

src/broadcast.h

@@ -11,6 +11,8 @@ class BroadCast: public QObject
 
 private:
 
+    bool master_;
+
     static constexpr uint8_t MODE_PREPACKET = 0;
     static constexpr uint8_t MODE_PACKET = 1;
 
@@ -22,18 +24,24 @@ private:
     void write(const QByteArray& buffer);
 
     void decode();
+    void decodeMaster();
 
 private slots:
 
     void readyRead();
 
+public slots:
+
+    void requestJson();
+
 signals:
 
+    void jsonRequested();
     void gotJson(QJsonObject json);
 
 public:
 
-    BroadCast(QIODevice* const iodevice = nullptr);
+    BroadCast(QIODevice* const iodevice = nullptr, bool master = true);
     void sendJson(const QJsonObject& json);
 
 };