QmlDebug: Modernize QmlDebugConnection

Use nullptr, auto, and initialize members inline.

Change-Id: Ie031057e8f4a3a74c22a86b343d8b5c265454550
Reviewed-by: Christian Kandeler <christian.kandeler@qt.io>
Reviewed-by: Alessandro Portale <alessandro.portale@qt.io>

src/libs/qmldebug/qmldebugconnection.cpp

@@ -45,17 +45,16 @@ const QString clientId = QLatin1String("QDeclarativeDebugClient");
 class QmlDebugConnectionPrivate
 {
 public:
-    QmlDebugConnectionPrivate();
-    QPacketProtocol *protocol;
-    QLocalServer *server;
-    QIODevice *device; // Currently a QTcpSocket or a QLocalSocket
+    QPacketProtocol *protocol = nullptr;
+    QLocalServer *server = nullptr;
+    QIODevice *device = nullptr; // Currently a QTcpSocket or a QLocalSocket
 
-    bool gotHello;
+    bool gotHello = false;
     QHash <QString, float> serverPlugins;
     QHash<QString, QmlDebugClient *> plugins;
 
-    int currentDataStreamVersion;
-    int maximumDataStreamVersion;
+    int currentDataStreamVersion = QmlDebugConnection::minimumDataStreamVersion();
+    int maximumDataStreamVersion = QDataStream::Qt_DefaultCompiledVersion;
 
     void advertisePlugins();
     void flush();
@@ -75,13 +74,6 @@ static QString socketErrorToString(QAbstractSocket::SocketError error)
     return QmlDebugConnection::tr("Error: %1").arg(errorString);
 }
 
-QmlDebugConnectionPrivate::QmlDebugConnectionPrivate() :
-    protocol(0), server(0), device(0), gotHello(false),
-    currentDataStreamVersion(QmlDebugConnection::minimumDataStreamVersion()),
-    maximumDataStreamVersion(QDataStream::Qt_DefaultCompiledVersion)
-{
-}
-
 void QmlDebugConnectionPrivate::advertisePlugins()
 {
     if (!gotHello)
@@ -118,7 +110,7 @@ void QmlDebugConnection::socketDisconnected()
     if (d->protocol) {
         d->protocol->disconnect();
         d->protocol->deleteLater();
-        d->protocol = 0;
+        d->protocol = nullptr;
     }
     if (d->device) {
         // Don't allow any "connected()" or "disconnected()" signals to be triggered anymore.
@@ -126,7 +118,7 @@ void QmlDebugConnection::socketDisconnected()
         d->device->disconnect();
         // Don't immediately delete it as it may do some cleanup on returning from a signal.
         d->device->deleteLater();
-        d->device = 0;
+        d->device = nullptr;
     }
 }
 
@@ -220,7 +212,7 @@ void QmlDebugConnection::protocolReadyRead()
 
                 QHash<QString, QmlDebugClient *>::Iterator iter = d->plugins.begin();
                 for (; iter != d->plugins.end(); ++iter) {
-                    const QString pluginName = iter.key();
+                    const QString &pluginName = iter.key();
                     QmlDebugClient::State newState = QmlDebugClient::Unavailable;
                     if (d->serverPlugins.contains(pluginName))
                         newState = QmlDebugClient::Enabled;
@@ -282,7 +274,7 @@ void QmlDebugConnection::close()
 QmlDebugClient *QmlDebugConnection::client(const QString &name) const
 {
     Q_D(const QmlDebugConnection);
-    return d->plugins.value(name, 0);
+    return d->plugins.value(name, nullptr);
 }
 
 bool QmlDebugConnection::addClient(const QString &name, QmlDebugClient *client)
@@ -324,16 +316,11 @@ bool QmlDebugConnection::sendMessage(const QString &name, const QByteArray &mess
     return true;
 }
 
-int QmlDebugConnection::minimumDataStreamVersion()
-{
-    return QDataStream::Qt_4_7;
-}
-
 void QmlDebugConnectionPrivate::flush()
 {
-    if (QAbstractSocket *socket = qobject_cast<QAbstractSocket *>(device))
+    if (auto socket = qobject_cast<QAbstractSocket *>(device))
         socket->flush();
-    else if (QLocalSocket *socket = qobject_cast<QLocalSocket *>(device))
+    else if (auto socket = qobject_cast<QLocalSocket *>(device))
         socket->flush();
 }
 
@@ -341,7 +328,7 @@ void QmlDebugConnection::connectToHost(const QString &hostName, quint16 port)
 {
     Q_D(QmlDebugConnection);
     socketDisconnected();
-    QTcpSocket *socket = new QTcpSocket(this);
+    auto socket = new QTcpSocket(this);
     socket->setProxy(QNetworkProxy::NoProxy);
     d->device = socket;
     d->protocol = new QPacketProtocol(socket, this);
@@ -420,12 +407,11 @@ void QmlDebugConnection::setMaximumDataStreamVersion(int maximumVersion)
 QAbstractSocket::SocketState QmlDebugConnection::socketState() const
 {
     Q_D(const QmlDebugConnection);
-    if (QAbstractSocket *socket = qobject_cast<QAbstractSocket *>(d->device))
+    if (auto socket = qobject_cast<QAbstractSocket *>(d->device))
         return socket->state();
-    else if (QLocalSocket *socket = qobject_cast<QLocalSocket *>(d->device))
+    if (auto socket = qobject_cast<QLocalSocket *>(d->device))
         return static_cast<QAbstractSocket::SocketState>(socket->state());
-    else
-        return QAbstractSocket::UnconnectedState;
+    return QAbstractSocket::UnconnectedState;
 }
 
 } // namespace QmlDebug

src/libs/qmldebug/qmldebugconnection.h

@@ -30,6 +30,7 @@
 #include <QObject>
 #include <QUrl>
 #include <QAbstractSocket>
+#include <QDataStream>
 
 namespace QmlDebug {
 
@@ -38,10 +39,9 @@ class QmlDebugConnectionPrivate;
 class QMLDEBUG_EXPORT QmlDebugConnection : public QObject
 {
     Q_OBJECT
-    Q_DISABLE_COPY(QmlDebugConnection)
     Q_DECLARE_PRIVATE(QmlDebugConnection)
 public:
-    QmlDebugConnection(QObject * = 0);
+    QmlDebugConnection(QObject *parent = nullptr);
     ~QmlDebugConnection() override;
 
     void connectToHost(const QString &hostName, quint16 port);
@@ -62,7 +62,10 @@ public:
     float serviceVersion(const QString &serviceName) const;
     bool sendMessage(const QString &name, const QByteArray &message);
 
-    static int minimumDataStreamVersion();
+    static constexpr int minimumDataStreamVersion()
+    {
+        return QDataStream::Qt_4_7;
+    }
 
 signals:
     void connected();