Implement mDNS PC discovery

app/backend/computermanager.h

@@ -1,6 +1,12 @@
 #pragma once
 #include "nvhttp.h"
 
+#include <qmdnsengine/server.h>
+#include <qmdnsengine/cache.h>
+#include <qmdnsengine/browser.h>
+#include <qmdnsengine/service.h>
+#include <qmdnsengine/resolver.h>
+
 #include <QThread>
 #include <QReadWriteLock>
 #include <QSettings>
@@ -207,6 +213,43 @@ private:
     NvComputer* m_Computer;
 };
 
+class MdnsPendingComputer : public QObject
+{
+    Q_OBJECT
+
+public:
+    explicit MdnsPendingComputer(QMdnsEngine::Server* server,
+                                 QMdnsEngine::Cache* cache,
+                                 const QMdnsEngine::Service& service)
+        : m_Hostname(service.hostname()),
+          m_Resolver(server, m_Hostname, cache)
+    {
+        connect(&m_Resolver, SIGNAL(resolved(QHostAddress)),
+                this, SLOT(handleResolved(QHostAddress)));
+    }
+
+    QString hostname()
+    {
+        return m_Hostname;
+    }
+
+private slots:
+    void handleResolved(const QHostAddress& address)
+    {
+        if (address.protocol() == QAbstractSocket::IPv4Protocol) {
+            m_Resolver.disconnect();
+            emit resolvedv4(this, address);
+        }
+    }
+
+signals:
+    void resolvedv4(MdnsPendingComputer*, const QHostAddress&);
+
+private:
+    QByteArray m_Hostname;
+    QMdnsEngine::Resolver m_Resolver;
+};
+
 class ComputerManager : public QObject
 {
     Q_OBJECT
@@ -231,6 +274,8 @@ signals:
 private slots:
     void handleComputerStateChanged(NvComputer* computer);
 
+    void handleMdnsServiceResolved(MdnsPendingComputer* computer, const QHostAddress& address);
+
 private:
     void saveHosts();
 
@@ -240,4 +285,8 @@ private:
     QReadWriteLock m_Lock;
     QMap<QString, NvComputer*> m_KnownHosts;
     QMap<QString, QThread*> m_PollThreads;
+    QMdnsEngine::Server m_MdnsServer;
+    QMdnsEngine::Browser* m_MdnsBrowser;
+    QMdnsEngine::Cache m_MdnsCache;
+    QVector<MdnsPendingComputer*> m_PendingResolution;
 };