QmlDebug: Decouple log messages from connection failures

A socket error is not the only possible reason for a connection failure
and exposing socket error codes to the upper layers is unnecessary.

Change-Id: I27e9f21160ecea5b0d811b83b7ab0ab9071cacff
Reviewed-by: hjk <hjk@qt.io>
Reviewed-by: Christian Kandeler <christian.kandeler@qt.io>

src/libs/qmldebug/qmldebugclient.cpp

@@ -68,34 +68,36 @@ public:
     void flush();
 };
 
-QString QmlDebugConnection::socketStateToString(QAbstractSocket::SocketState state)
+static QString socketStateToString(QAbstractSocket::SocketState state)
 {
     switch (state) {
     case QAbstractSocket::UnconnectedState:
-        return tr("Network connection dropped");
+        return QmlDebugConnection::tr("Network connection dropped");
     case QAbstractSocket::HostLookupState:
-        return tr("Resolving host");
+        return QmlDebugConnection::tr("Resolving host");
     case QAbstractSocket::ConnectingState:
-        return tr("Establishing network connection ...");
+        return QmlDebugConnection::tr("Establishing network connection ...");
     case QAbstractSocket::ConnectedState:
-        return tr("Network connection established");
+        return QmlDebugConnection::tr("Network connection established");
     case QAbstractSocket::ClosingState:
-        return tr("Network connection closing");
+        return QmlDebugConnection::tr("Network connection closing");
     case QAbstractSocket::BoundState:
-        return tr("Socket state changed to BoundState. This should not happen!");
+        return QmlDebugConnection::tr("Socket state changed to BoundState. "
+                                      "This should not happen!");
     case QAbstractSocket::ListeningState:
-        return tr("Socket state changed to ListeningState. This should not happen!");
+        return QmlDebugConnection::tr("Socket state changed to ListeningState. "
+                                      "This should not happen!");
     default:
-        return tr("Unknown state %1").arg(state);
+        return QmlDebugConnection::tr("Unknown state %1").arg(state);
     }
 }
 
-QString QmlDebugConnection::socketErrorToString(QAbstractSocket::SocketError error)
+static QString socketErrorToString(QAbstractSocket::SocketError error)
 {
     if (error == QAbstractSocket::RemoteHostClosedError) {
-        return tr("Error: Remote host closed the connection");
+        return QmlDebugConnection::tr("Error: Remote host closed the connection");
     } else {
-        return tr("Error: Unknown socket error %1").arg(error);
+        return QmlDebugConnection::tr("Error: Unknown socket error %1").arg(error);
     }
 }
 
@@ -136,6 +138,8 @@ void QmlDebugConnection::socketDisconnected()
         for (; iter != d->plugins.end(); ++iter)
             iter.value()->stateChanged(QmlDebugClient::NotConnected);
         emit disconnected();
+    } else if (d->device) {
+        emit connectionFailed();
     }
     delete d->protocol;
     d->protocol = 0;
@@ -365,9 +369,16 @@ void QmlDebugConnection::connectToHost(const QString &hostName, quint16 port)
     d->protocol = new QPacketProtocol(socket, this);
     QObject::connect(d->protocol, &QPacketProtocol::readyRead,
                      this, &QmlDebugConnection::protocolReadyRead);
-    connect(socket, &QAbstractSocket::stateChanged, this, &QmlDebugConnection::socketStateChanged);
+    connect(socket, &QAbstractSocket::stateChanged,
+            this, [this](QAbstractSocket::SocketState state) {
+        emit logStateChange(socketStateToString(state));
+    });
+
     connect(socket, static_cast<void (QTcpSocket::*)(QAbstractSocket::SocketError)>
-            (&QAbstractSocket::error), this, &QmlDebugConnection::socketError);
+            (&QAbstractSocket::error), this, [this](QAbstractSocket::SocketError error) {
+        emit logError(socketErrorToString(error));
+        socketDisconnected();
+    });
     connect(socket, &QAbstractSocket::connected, this, &QmlDebugConnection::socketConnected);
     connect(socket, &QAbstractSocket::disconnected, this, &QmlDebugConnection::socketDisconnected);
     socket->connectToHost(hostName, port);
@@ -385,7 +396,7 @@ void QmlDebugConnection::startLocalServer(const QString &fileName)
     connect(d->server, &QLocalServer::newConnection,
             this, &QmlDebugConnection::newConnection, Qt::QueuedConnection);
     if (!d->server->listen(fileName))
-        emit socketError(QAbstractSocket::UnknownSocketError);
+        emit connectionFailed();
 }
 
 void QmlDebugConnection::newConnection()
@@ -403,13 +414,14 @@ void QmlDebugConnection::newConnection()
     connect(socket, &QLocalSocket::disconnected, this, &QmlDebugConnection::socketDisconnected);
 
     connect(socket, static_cast<void (QLocalSocket::*)(QLocalSocket::LocalSocketError)>
-            (&QLocalSocket::error), this, [this](QLocalSocket::LocalSocketError error) {
-        socketError(static_cast<QAbstractSocket::SocketError>(error));
+            (&QLocalSocket::error), this, [this, d](QLocalSocket::LocalSocketError error) {
+        logError(socketErrorToString(static_cast<QAbstractSocket::SocketError>(error)));
+        socketDisconnected();
     });
 
     connect(socket, &QLocalSocket::stateChanged,
             this, [this](QLocalSocket::LocalSocketState state) {
-        socketStateChanged(static_cast<QAbstractSocket::SocketState>(state));
+        logStateChange(socketStateToString(static_cast<QAbstractSocket::SocketState>(state)));
     });
 
     socketConnected();

src/libs/qmldebug/qmldebugclient.h

@@ -61,14 +61,13 @@ public:
     float serviceVersion(const QString &serviceName) const;
     bool sendMessage(const QString &name, const QByteArray &message);
 
-    static QString socketStateToString(QAbstractSocket::SocketState state);
-    static QString socketErrorToString(QAbstractSocket::SocketError error);
-
 signals:
     void connected();
     void disconnected();
-    void socketError(QAbstractSocket::SocketError error);
-    void socketStateChanged(QAbstractSocket::SocketState state);
+    void connectionFailed();
+
+    void logError(const QString &error);
+    void logStateChange(const QString &state);
 
 private:
     void newConnection();

src/plugins/debugger/qml/qmlengine.cpp

@@ -289,10 +289,13 @@ QmlEngine::QmlEngine(const DebuggerRunParameters &startParameters, DebuggerEngin
     connect(&d->connectionTimer, &QTimer::timeout,
             this, &QmlEngine::checkConnectionState);
 
-    connect(d->connection, &QmlDebugConnection::socketStateChanged,
-            this, &QmlEngine::connectionStateChanged);
-    connect(d->connection, &QmlDebugConnection::socketError,
-            this, &QmlEngine::connectionErrorOccurred);
+    connect(d->connection, &QmlDebugConnection::logStateChange,
+            this, &QmlEngine::showConnectionStateMessage);
+    connect(d->connection, &QmlDebugConnection::logError, this,
+            [this](const QString &error) { showMessage("QML Debugger: " + error, StatusBar); });
+
+    connect(d->connection, &QmlDebugConnection::connectionFailed,
+            this, &QmlEngine::connectionFailed);
     connect(d->connection, &QmlDebugConnection::connected,
             &d->connectionTimer, &QTimer::stop);
     connect(d->connection, &QmlDebugConnection::connected,
@@ -1200,13 +1203,10 @@ bool QmlEnginePrivate::canEvaluateScript(const QString &script)
     return interpreter.canEvaluate();
 }
 
-void QmlEngine::connectionErrorOccurred(QAbstractSocket::SocketError error)
+void QmlEngine::connectionFailed()
 {
     // this is only an error if we are already connected and something goes wrong.
     if (isConnected()) {
-        if (error == QAbstractSocket::RemoteHostClosedError)
-            showMessage(tr("QML Debugger: Remote host closed connection."), StatusBar);
-
         if (!isSlaveEngine()) { // normal flow for slave engine when gdb exits
             notifyInferiorSpontaneousStop();
             notifyInferiorIll();
@@ -1217,11 +1217,6 @@ void QmlEngine::connectionErrorOccurred(QAbstractSocket::SocketError error)
     }
 }
 
-void QmlEngine::connectionStateChanged(QAbstractSocket::SocketState socketState)
-{
-    showConnectionStateMessage(QmlDebugConnection::socketStateToString(socketState));
-}
-
 void QmlEngine::checkConnectionState()
 {
     if (!isConnected()) {

src/plugins/debugger/qml/qmlengine.h

@@ -133,8 +133,7 @@ private:
     void startApplicationLauncher();
     void stopApplicationLauncher();
 
-    void connectionErrorOccurred(QAbstractSocket::SocketError socketError);
-    void connectionStateChanged(QAbstractSocket::SocketState socketState);
+    void connectionFailed();
 
     void checkConnectionState();
     void showConnectionStateMessage(const QString &message);

src/plugins/qmlprofiler/qmlprofilerclientmanager.cpp

@@ -179,10 +179,13 @@ void QmlProfilerClientManager::createConnection()
             this, &QmlProfilerClientManager::qmlDebugConnectionOpened);
     connect(d->connection, &QmlDebug::QmlDebugConnection::disconnected,
             this, &QmlProfilerClientManager::qmlDebugConnectionClosed);
-    connect(d->connection, &QmlDebug::QmlDebugConnection::socketError,
-            this, &QmlProfilerClientManager::qmlDebugConnectionError);
-    connect(d->connection, &QmlDebug::QmlDebugConnection::socketStateChanged,
-            this, &QmlProfilerClientManager::qmlDebugConnectionStateChanged);
+    connect(d->connection, &QmlDebug::QmlDebugConnection::connectionFailed,
+            this, &QmlProfilerClientManager::qmlDebugConnectionFailed);
+
+    connect(d->connection, &QmlDebug::QmlDebugConnection::logError,
+            this, &QmlProfilerClientManager::logState);
+    connect(d->connection, &QmlDebug::QmlDebugConnection::logStateChange,
+            this, &QmlProfilerClientManager::logState);
 }
 
 void QmlProfilerClientManager::retryConnect()
@@ -294,9 +297,8 @@ void QmlProfilerClientManager::qmlDebugConnectionClosed()
     emit connectionClosed();
 }
 
-void QmlProfilerClientManager::qmlDebugConnectionError(QAbstractSocket::SocketError error)
+void QmlProfilerClientManager::qmlDebugConnectionFailed()
 {
-    logState(QmlDebug::QmlDebugConnection::socketErrorToString(error));
     if (d->connection->isConnected()) {
         disconnectClient();
         emit connectionClosed();
@@ -305,11 +307,6 @@ void QmlProfilerClientManager::qmlDebugConnectionError(QAbstractSocket::SocketEr
     }
 }
 
-void QmlProfilerClientManager::qmlDebugConnectionStateChanged(QAbstractSocket::SocketState state)
-{
-    logState(QmlDebug::QmlDebugConnection::socketStateToString(state));
-}
-
 void QmlProfilerClientManager::logState(const QString &msg)
 {
     QmlProfilerTool::logState(QLatin1String("QML Profiler: ") + msg);

src/plugins/qmlprofiler/qmlprofilerclientmanager.h

@@ -72,8 +72,8 @@ private slots:
     void tryToConnect();
     void qmlDebugConnectionOpened();
     void qmlDebugConnectionClosed();
-    void qmlDebugConnectionError(QAbstractSocket::SocketError error);
-    void qmlDebugConnectionStateChanged(QAbstractSocket::SocketState state);
+    void qmlDebugConnectionFailed();
+
     void logState(const QString &);
 
     void qmlComplete(qint64 maximumTime);