QmlDebug: Parse application output to track debugees state

Setting up the debugger connection might fail for a couple of reasons.
Check the application output to show the user a more detailed error
message.

Reviewed-by: hjk

src/plugins/debugger/debuggerengine.h

@@ -244,7 +244,7 @@ public:
     void handleCommand(int role, const QVariant &value);
 
     // Convenience
-    Q_SLOT void showMessage(const QString &msg, int channel = LogDebug,
+    Q_SLOT virtual void showMessage(const QString &msg, int channel = LogDebug,
         int timeout = -1) const;
     Q_SLOT void showStatusMessage(const QString &msg, int timeout = -1) const;
 

src/plugins/debugger/debuggerrunner.cpp

@@ -43,6 +43,7 @@
 #include "debuggerstartparameters.h"
 #include "lldb/lldbenginehost.h"
 #include "debuggertooltipmanager.h"
+#include "qml/qmlengine.h"
 
 #ifdef Q_OS_WIN
 #  include "peutils.h"
@@ -82,7 +83,7 @@ DebuggerEngine *createGdbEngine(const DebuggerStartParameters &sp,
 DebuggerEngine *createScriptEngine(const DebuggerStartParameters &sp);
 DebuggerEngine *createPdbEngine(const DebuggerStartParameters &sp);
 DebuggerEngine *createTcfEngine(const DebuggerStartParameters &sp);
-DebuggerEngine *createQmlEngine(const DebuggerStartParameters &sp,
+QmlEngine *createQmlEngine(const DebuggerStartParameters &sp,
     DebuggerEngine *masterEngine);
 DebuggerEngine *createQmlCppEngine(const DebuggerStartParameters &sp);
 DebuggerEngine *createLldbEngine(const DebuggerStartParameters &sp);

src/plugins/debugger/gdb/gdbengine.cpp

@@ -321,7 +321,7 @@ void GdbEngine::readDebugeeOutput(const QByteArray &data)
 {
     QString msg = m_outputCodec->toUnicode(data.constData(), data.length(),
         &m_outputCodecState);
-    showMessage(msg, AppStuff);
+    showMessage(msg, AppOutput);
 }
 
 void GdbEngine::handleResponse(const QByteArray &buff)

src/plugins/debugger/qml/qmlcppengine.cpp

@@ -36,6 +36,7 @@
 #include "debuggercore.h"
 #include "debuggerstartparameters.h"
 #include "stackhandler.h"
+#include "qmlengine.h"
 
 #include <utils/qtcassert.h>
 
@@ -53,7 +54,7 @@ DebuggerEngine *createCdbEngine(const DebuggerStartParameters &,
     DebuggerEngine *masterEngine, QString *);
 DebuggerEngine *createGdbEngine(const DebuggerStartParameters &,
     DebuggerEngine *masterEngine);
-DebuggerEngine *createQmlEngine(const DebuggerStartParameters &,
+QmlEngine *createQmlEngine(const DebuggerStartParameters &,
     DebuggerEngine *masterEngine);
 
 DebuggerEngine *createQmlCppEngine(const DebuggerStartParameters &sp)
@@ -88,7 +89,7 @@ private slots:
 private:
     friend class QmlCppEngine;
     QmlCppEngine *q;
-    DebuggerEngine *m_qmlEngine;
+    QmlEngine *m_qmlEngine;
     DebuggerEngine *m_cppEngine;
     DebuggerEngine *m_activeEngine;
     int m_stackBoundary;
@@ -664,6 +665,15 @@ void QmlCppEngine::handleRemoteSetupFailed(const QString &message)
     d->m_cppEngine->handleRemoteSetupFailed(message);
 }
 
+void QmlCppEngine::showMessage(const QString &msg, int channel, int timeout) const
+{
+    if (channel == AppOutput || channel == AppError) {
+        // message is from CppEngine, allow qml engine to process
+        d->m_qmlEngine->filterApplicationMessage(msg, channel);
+    }
+    DebuggerEngine::showMessage(msg, channel, timeout);
+}
+
 DebuggerEngine *QmlCppEngine::cppEngine() const
 {
     return d->m_cppEngine;

src/plugins/debugger/qml/qmlcppengine.h

@@ -91,6 +91,9 @@ public:
     void handleRemoteSetupDone(int gdbServerPort, int qmlPort);
     void handleRemoteSetupFailed(const QString &message);
 
+    void showMessage(const QString &msg, int channel = LogDebug,
+        int timeout = -1) const;
+
 protected:
     void detachDebugger();
     void executeStep();

src/plugins/debugger/qml/qmlengine.cpp

@@ -57,6 +57,7 @@
 #include <utils/environment.h>
 #include <utils/qtcassert.h>
 
+#include <coreplugin/icore.h>
 #include <coreplugin/helpmanager.h>
 
 #include <QtCore/QDateTime>
@@ -216,7 +217,7 @@ void QmlEngine::setupInferior()
 
 void QmlEngine::appendMessage(const QString &msg, OutputFormat /* format */)
 {
-    showMessage(msg, AppStuff); // FIXME: Redirect to RunControl
+    showMessage(msg, AppOutput); // FIXME: Redirect to RunControl
 }
 
 void QmlEngine::connectionEstablished()
@@ -277,6 +278,70 @@ bool QmlEngine::canDisplayTooltip() const
     return state() == InferiorRunOk || state() == InferiorStopOk;
 }
 
+void QmlEngine::filterApplicationMessage(const QString &msg, int /*channel*/)
+{
+    static QString qddserver = QLatin1String("QDeclarativeDebugServer: ");
+    static QString cannotRetrieve = "Cannot retrieve debugging output!";
+
+    int index = msg.indexOf(qddserver);
+    if (index != -1) {
+        QString status = msg;
+        status.remove(0, index + qddserver.length()); // chop of 'QDeclarativeDebugServer: '
+
+        static QString waitingForConnection = QLatin1String("Waiting for connection on port");
+        static QString unableToListen = QLatin1String("Unable to listen on port");
+        static QString debuggingNotEnabled = QLatin1String("Ignoring \"-qmljsdebugger=port:");
+        static QString connectionEstablished = QLatin1String("Connection established");
+
+        QString errorMessage;
+        if (status.startsWith(waitingForConnection)) {
+            d->m_adapter.beginConnection();
+        } else if (status.startsWith(unableToListen)) {
+            errorMessage = tr("The port seems to be in use.");
+        } else if (status.startsWith(debuggingNotEnabled)) {
+            errorMessage = tr("The application isn't set up for QML/JS debugging.");
+        } else if (status.startsWith(connectionEstablished)) {
+            // nothing to do
+        } else {
+            qWarning() << "Unknown QDeclarativeDebugServer status message: " << status;
+        }
+
+        if (!errorMessage.isEmpty()) {
+            notifyEngineRunFailed();
+
+            Core::ICore * const core = Core::ICore::instance();
+            QMessageBox *infoBox = new QMessageBox(core->mainWindow());
+            infoBox->setIcon(QMessageBox::Critical);
+            infoBox->setWindowTitle(tr("Qt Creator"));
+            infoBox->setText(tr("Failed to connect to QML debugger\n\n"
+                                "Qt Creator could not connect to the in-process debugger at %1:%2:\n"
+                                "%3")
+                             .arg(startParameters().qmlServerAddress)
+                             .arg(startParameters().qmlServerPort)
+                             .arg(errorMessage));
+            infoBox->setStandardButtons(QMessageBox::Ok | QMessageBox::Help);
+            infoBox->setDefaultButton(QMessageBox::Ok);
+            infoBox->setModal(true);
+
+            connect(infoBox, SIGNAL(finished(int)),
+                    this, SLOT(messageBoxFinished(int)));
+
+            infoBox->show();
+        }
+    } else if (msg.contains(cannotRetrieve)) {
+        // we won't get debugging output, so just try to connect ...
+        d->m_adapter.beginConnection();
+    }
+}
+
+void QmlEngine::showMessage(const QString &msg, int channel, int timeout) const
+{
+    if (channel == AppOutput || channel == AppError) {
+        const_cast<QmlEngine*>(this)->filterApplicationMessage(msg, channel);
+    }
+    DebuggerEngine::showMessage(msg, channel, timeout);
+}
+
 void QmlEngine::closeConnection()
 {
     disconnect(&d->m_adapter, SIGNAL(connectionStartupFailed()),
@@ -298,8 +363,6 @@ void QmlEngine::runEngine()
 
     if (!isSlaveEngine())
         startApplicationLauncher();
-
-    d->m_adapter.beginConnection();
 }
 
 void QmlEngine::startApplicationLauncher()
@@ -871,6 +934,15 @@ void QmlEngine::disconnected()
     notifyInferiorExited();
 }
 
+void QmlEngine::messageBoxFinished(int result)
+{
+    if (result == QMessageBox::Help) {
+        Core::HelpManager *helpManager = Core::HelpManager::instance();
+        helpManager->handleHelpRequest(
+                    QLatin1String("qthelp://com.nokia.qtcreator/doc/creator-debugging-qml.html"));
+    }
+}
+
 void QmlEngine::executeDebuggerCommand(const QString& command)
 {
     QByteArray reply;
@@ -959,7 +1031,7 @@ void QmlEngine::logMessage(LogDirection direction, const QString &message)
     showMessage(msg, LogDebug);
 }
 
-DebuggerEngine *createQmlEngine(const DebuggerStartParameters &sp,
+QmlEngine *createQmlEngine(const DebuggerStartParameters &sp,
     DebuggerEngine *masterEngine)
 {
     return new QmlEngine(sp, masterEngine);

src/plugins/debugger/qml/qmlengine.h

@@ -61,10 +61,17 @@ public:
     void gotoLocation(const Location &location);
     bool canDisplayTooltip() const;
 
+    void showMessage(const QString &msg, int channel = LogDebug,
+                     int timeout = -1) const;
+    void filterApplicationMessage(const QString &msg, int channel);
+
 public slots:
     void messageReceived(const QByteArray &message);
     void disconnected();
 
+private slots:
+    void messageBoxFinished(int result);
+
 private:
     // DebuggerEngine implementation.
     bool isSynchronous() const { return false; }