Add basic client/server debugging support

The canvas framerate monitor now uses this support.

7 files changed, 1202 insertions, 2 deletions

diff --git a/src/declarative/debugger/debugger.pri b/src/declarative/debugger/debugger.pri
index c386d74..121cb98 100644
--- a/src/declarative/debugger/debugger.pri
+++ b/src/declarative/debugger/debugger.pri
@@ -3,11 +3,17 @@ SOURCES += debugger/qmldebugger.cpp \
            debugger/qmlpropertyview.cpp \
            debugger/qmlwatches.cpp \
            debugger/qmlobjecttree.cpp \
-           debugger/qmlcanvasdebugger.cpp
+           debugger/qmlcanvasdebugger.cpp \
+           debugger/qpacketprotocol.cpp \
+           debugger/qmldebugserver.cpp \
+           debugger/qmldebugclient.cpp
 
 HEADERS += debugger/qmldebugger.h \
            debugger/qmldebuggerstatus.h \
            debugger/qmlpropertyview_p.h \
            debugger/qmlwatches_p.h \
            debugger/qmlobjecttree_p.h \
-           debugger/qmlcanvasdebugger_p.h
+           debugger/qmlcanvasdebugger_p.h \
+           debugger/qpacketprotocol.h \
+           debugger/qmldebugserver.h \
+           debugger/qmldebugclient.h
diff --git a/src/declarative/debugger/qmldebugclient.cpp b/src/declarative/debugger/qmldebugclient.cpp
new file mode 100644
index 0000000..7a304ef
--- /dev/null
+++ b/src/declarative/debugger/qmldebugclient.cpp
@@ -0,0 +1,190 @@
+/****************************************************************************
+**
+** Copyright (C) 2009 Nokia Corporation and/or its subsidiary(-ies).
+** Contact: Qt Software Information (qt-info@nokia.com)
+**
+** This file is part of the QtDeclarative module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** No Commercial Usage
+** This file contains pre-release code and may not be distributed.
+** You may use this file in accordance with the terms and conditions
+** contained in the either Technology Preview License Agreement or the
+** Beta Release License Agreement.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 2.1 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL included in the
+** packaging of this file.  Please review the following information to
+** ensure the GNU Lesser General Public License version 2.1 requirements
+** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
+**
+** In addition, as a special exception, Nokia gives you certain
+** additional rights. These rights are described in the Nokia Qt LGPL
+** Exception version 1.0, included in the file LGPL_EXCEPTION.txt in this
+** package.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 3.0 as published by the Free Software
+** Foundation and appearing in the file LICENSE.GPL included in the
+** packaging of this file.  Please review the following information to
+** ensure the GNU General Public License version 3.0 requirements will be
+** met: http://www.gnu.org/copyleft/gpl.html.
+**
+** If you are unsure which license is appropriate for your use, please
+** contact the sales department at qt-sales@nokia.com.
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#include "qmldebugclient.h"
+#include <private/qtcpsocket_p.h>
+#include <QtDeclarative/qpacketprotocol.h>
+#include <QtCore/qdebug.h>
+#include <QtCore/qstringlist.h>
+
+QT_BEGIN_NAMESPACE
+
+class QmlDebugClientPrivate : public QObject
+{
+    Q_OBJECT
+public:
+    QmlDebugClientPrivate(QmlDebugClient *c);
+    QmlDebugClient *q;
+    QPacketProtocol *protocol;
+
+    QStringList enabled;
+    QHash<QString, QmlDebugClientPlugin *> plugins;
+public slots:
+    void connected();
+    void readyRead();
+};
+
+QmlDebugClientPrivate::QmlDebugClientPrivate(QmlDebugClient *c)
+: QObject(c), q(c), protocol(0)
+{
+    protocol = new QPacketProtocol(q, this);
+    QObject::connect(c, SIGNAL(connected()), this, SLOT(connected()));
+    QObject::connect(protocol, SIGNAL(readyRead()), this, SLOT(readyRead()));
+}
+
+void QmlDebugClientPrivate::connected()
+{
+    QPacket pack;
+    pack << QString(QLatin1String("QmlDebugServer")) << QStringList();
+    protocol->send(pack);
+}
+
+void QmlDebugClientPrivate::readyRead()
+{
+    QPacket pack = protocol->read();
+    QString name; QByteArray message;
+    pack >> name >> message;
+
+    QHash<QString, QmlDebugClientPlugin *>::Iterator iter = 
+        plugins.find(name);
+    if (iter == plugins.end()) {
+        qWarning() << "QmlDebugClient: Message received for missing plugin" << name;
+    } else {
+        (*iter)->messageReceived(message);
+    }
+}
+
+QmlDebugClient::QmlDebugClient(QObject *parent)
+: QTcpSocket(parent), d(new QmlDebugClientPrivate(this))
+{
+}
+
+class QmlDebugClientPluginPrivate : public QObjectPrivate
+{
+    Q_DECLARE_PUBLIC(QmlDebugClientPlugin);
+public:
+    QmlDebugClientPluginPrivate();
+
+    QString name;
+    QmlDebugClient *client;
+    bool enabled;
+};
+
+QmlDebugClientPluginPrivate::QmlDebugClientPluginPrivate()
+: client(0), enabled(false)
+{
+}
+
+QmlDebugClientPlugin::QmlDebugClientPlugin(const QString &name, 
+                                           QmlDebugClient *parent)
+: QObject(*(new QmlDebugClientPluginPrivate), parent)
+{
+    Q_D(QmlDebugClientPlugin);
+    d->name = name;
+    d->client = parent;
+
+    if (!d->client)
+        return;
+
+    if (d->client->d->plugins.contains(name)) {
+        qWarning() << "QmlDebugClientPlugin: Conflicting plugin name" << name;
+        d->client = 0;
+    } else {
+        d->client->d->plugins.insert(name, this);
+    }
+}
+
+QString QmlDebugClientPlugin::name() const
+{
+    Q_D(const QmlDebugClientPlugin);
+    return d->name;
+}
+
+bool QmlDebugClientPlugin::isEnabled() const
+{
+    Q_D(const QmlDebugClientPlugin);
+    return d->enabled;
+}
+
+void QmlDebugClientPlugin::setEnabled(bool e)
+{
+    Q_D(QmlDebugClientPlugin);
+    if (e == d->enabled)
+        return;
+
+    d->enabled = e;
+
+    if (d->client) {
+        if (e) 
+            d->client->d->enabled.append(d->name);
+        else
+            d->client->d->enabled.removeAll(d->name);
+
+        if (d->client->state() == QTcpSocket::ConnectedState) {
+            QPacket pack;
+            pack << QString(QLatin1String("QmlDebugServer"));
+            if (e) pack << (int)1;
+            else pack << (int)2;
+            pack << d->name;
+            d->client->d->protocol->send(pack);
+        }
+    }
+}
+
+void QmlDebugClientPlugin::sendMessage(const QByteArray &message)
+{
+    Q_D(QmlDebugClientPlugin);
+
+    if (!d->client || d->client->state() != QTcpSocket::ConnectedState)
+        return;
+
+    QPacket pack;
+    pack << d->name << message;
+    d->client->d_func()->protocol->send(pack);
+}
+
+void QmlDebugClientPlugin::messageReceived(const QByteArray &)
+{
+}
+
+#include "qmldebugclient.moc"
+
+QT_END_NAMESPACE
diff --git a/src/declarative/debugger/qmldebugclient.h b/src/declarative/debugger/qmldebugclient.h
new file mode 100644
index 0000000..d765822
--- /dev/null
+++ b/src/declarative/debugger/qmldebugclient.h
@@ -0,0 +1,97 @@
+/****************************************************************************
+**
+** Copyright (C) 2009 Nokia Corporation and/or its subsidiary(-ies).
+** Contact: Qt Software Information (qt-info@nokia.com)
+**
+** This file is part of the QtDeclarative module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** No Commercial Usage
+** This file contains pre-release code and may not be distributed.
+** You may use this file in accordance with the terms and conditions
+** contained in the either Technology Preview License Agreement or the
+** Beta Release License Agreement.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 2.1 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL included in the
+** packaging of this file.  Please review the following information to
+** ensure the GNU Lesser General Public License version 2.1 requirements
+** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
+**
+** In addition, as a special exception, Nokia gives you certain
+** additional rights. These rights are described in the Nokia Qt LGPL
+** Exception version 1.0, included in the file LGPL_EXCEPTION.txt in this
+** package.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 3.0 as published by the Free Software
+** Foundation and appearing in the file LICENSE.GPL included in the
+** packaging of this file.  Please review the following information to
+** ensure the GNU General Public License version 3.0 requirements will be
+** met: http://www.gnu.org/copyleft/gpl.html.
+**
+** If you are unsure which license is appropriate for your use, please
+** contact the sales department at qt-sales@nokia.com.
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#ifndef QMLDEBUGCLIENT_H
+#define QMLDEBUGCLIENT_H
+
+#include <QtNetwork/qtcpsocket.h>
+
+QT_BEGIN_HEADER
+
+QT_BEGIN_NAMESPACE
+
+QT_MODULE(Declarative)
+
+class QmlDebugClientPrivate;
+class Q_DECLARATIVE_EXPORT QmlDebugClient : public QTcpSocket
+{
+    Q_OBJECT
+    Q_DECLARE_PRIVATE(QmlDebugClient)
+    Q_DISABLE_COPY(QmlDebugClient)
+public:
+    QmlDebugClient(QObject * = 0);
+
+private:
+    QmlDebugClientPrivate *d;
+    friend class QmlDebugClientPlugin;
+    friend class QmlDebugClientPluginPrivate;
+};
+
+class QmlDebugClientPluginPrivate;
+class Q_DECLARATIVE_EXPORT QmlDebugClientPlugin : public QObject
+{
+    Q_OBJECT
+    Q_DECLARE_PRIVATE(QmlDebugClientPlugin)
+    Q_DISABLE_COPY(QmlDebugClientPlugin)
+
+public:
+    QmlDebugClientPlugin(const QString &, QmlDebugClient *parent);
+
+    QString name() const;
+
+    bool isEnabled() const;
+    void setEnabled(bool);
+
+    void sendMessage(const QByteArray &);
+
+protected:
+    virtual void messageReceived(const QByteArray &);
+
+private:
+    friend class QmlDebugClient;
+    friend class QmlDebugClientPrivate;
+};
+
+QT_END_NAMESPACE
+
+QT_END_HEADER
+
+#endif // QMLDEBUGCLIENT_H
diff --git a/src/declarative/debugger/qmldebugserver.cpp b/src/declarative/debugger/qmldebugserver.cpp
new file mode 100644
index 0000000..bce7e6d
--- /dev/null
+++ b/src/declarative/debugger/qmldebugserver.cpp
@@ -0,0 +1,283 @@
+/****************************************************************************
+**
+** Copyright (C) 2009 Nokia Corporation and/or its subsidiary(-ies).
+** Contact: Qt Software Information (qt-info@nokia.com)
+**
+** This file is part of the QtDeclarative module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** No Commercial Usage
+** This file contains pre-release code and may not be distributed.
+** You may use this file in accordance with the terms and conditions
+** contained in the either Technology Preview License Agreement or the
+** Beta Release License Agreement.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 2.1 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL included in the
+** packaging of this file.  Please review the following information to
+** ensure the GNU Lesser General Public License version 2.1 requirements
+** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
+**
+** In addition, as a special exception, Nokia gives you certain
+** additional rights. These rights are described in the Nokia Qt LGPL
+** Exception version 1.0, included in the file LGPL_EXCEPTION.txt in this
+** package.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 3.0 as published by the Free Software
+** Foundation and appearing in the file LICENSE.GPL included in the
+** packaging of this file.  Please review the following information to
+** ensure the GNU General Public License version 3.0 requirements will be
+** met: http://www.gnu.org/copyleft/gpl.html.
+**
+** If you are unsure which license is appropriate for your use, please
+** contact the sales department at qt-sales@nokia.com.
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#include "qmldebugserver.h"
+#include <QtCore/qdebug.h>
+#include <QtNetwork/qtcpserver.h>
+#include <QtNetwork/qtcpsocket.h>
+#include <private/qobject_p.h>
+#include <QtDeclarative/qpacketprotocol.h>
+#include <QtCore/qstringlist.h>
+
+QT_BEGIN_NAMESPACE
+
+class QmlDebugServerPrivate;
+class QmlDebugServer : public QObject
+{
+    Q_OBJECT
+    Q_DECLARE_PRIVATE(QmlDebugServer)
+    Q_DISABLE_COPY(QmlDebugServer)
+public:
+    static QmlDebugServer *instance();
+
+private slots:
+    void readyRead();
+
+private:
+    friend class QmlDebugServerPlugin;
+    friend class QmlDebugServerPluginPrivate;
+    QmlDebugServer(int); 
+};
+
+class QmlDebugServerPrivate : public QObjectPrivate
+{
+    Q_DECLARE_PUBLIC(QmlDebugServer);
+public:
+    QmlDebugServerPrivate();
+    void init(int port);
+
+    QTcpSocket *connection;
+    QPacketProtocol *protocol;
+    QHash<QString, QmlDebugServerPlugin *> plugins;
+    QStringList enabledPlugins;
+};
+
+class QmlDebugServerPluginPrivate : public QObjectPrivate
+{
+    Q_DECLARE_PUBLIC(QmlDebugServerPlugin);
+public:
+    QmlDebugServerPluginPrivate();
+
+    QString name;
+    QmlDebugServer *server;
+};
+
+QmlDebugServerPrivate::QmlDebugServerPrivate()
+: connection(0), protocol(0)
+{
+}
+
+void QmlDebugServerPrivate::init(int port)
+{
+    Q_Q(QmlDebugServer);
+    QTcpServer server;
+
+    if (!server.listen(QHostAddress::Any, port)) {
+        qWarning("QmlDebugServer: Unable to listen on port %d", port);
+        return;
+    }
+
+    qWarning("QmlDebugServer: Waiting for connection on port %d...", port);
+
+    if (!server.waitForNewConnection(-1)) {
+        qWarning("QmlDebugServer: Connection error");
+        return;
+    }
+
+    connection = server.nextPendingConnection();
+    connection->setParent(q);
+    protocol = new QPacketProtocol(connection, q);
+
+    // ### Wait for hello
+    while (!protocol->packetsAvailable()) {
+        connection->waitForReadyRead();
+    }
+    QPacket hello = protocol->read();
+    QString name; 
+    hello >> name >> enabledPlugins;
+    if (name != QLatin1String("QmlDebugServer")) {
+        qWarning("QmlDebugServer: Invalid hello message");
+        delete protocol; delete connection; connection = 0; protocol = 0;
+        return;
+    }
+
+    QObject::connect(protocol, SIGNAL(readyRead()), q, SLOT(readyRead()));
+    q->readyRead();
+
+    qWarning("QmlDebugServer: Connection established");
+}
+
+QmlDebugServer *QmlDebugServer::instance()
+{
+    static bool envTested = false;
+    static QmlDebugServer *server = 0;
+
+    if (!envTested) {
+        envTested = true;
+        QByteArray env = qgetenv("QML_DEBUG_SERVER_PORT");
+
+        bool ok = false;
+        int port = env.toInt(&ok);
+
+        if (ok && port > 1024) 
+            server = new QmlDebugServer(port);
+    }
+
+    if (server && server->d_func()->connection)
+        return server;
+    else
+        return 0;
+}
+
+QmlDebugServer::QmlDebugServer(int port)
+: QObject(*(new QmlDebugServerPrivate))
+{
+    Q_D(QmlDebugServer);
+    d->init(port);
+}
+
+void QmlDebugServer::readyRead()
+{
+    Q_D(QmlDebugServer);
+
+    QString debugServer(QLatin1String("QmlDebugServer"));
+
+    while (d->protocol->packetsAvailable()) {
+        QPacket pack = d->protocol->read();
+
+        QString name;
+        pack >> name;
+
+        if (name == debugServer) {
+            int op = -1; QString plugin;
+            pack >> op >> plugin;
+
+            if (op == 1) {
+                // Enable
+                if (!d->enabledPlugins.contains(plugin)) {
+                    d->enabledPlugins.append(plugin);
+                    QHash<QString, QmlDebugServerPlugin *>::Iterator iter = 
+                        d->plugins.find(plugin);
+                    if (iter != d->plugins.end())
+                        (*iter)->enabledChanged(true);
+                }
+
+            } else if (op == 2) {
+                // Disable
+                if (d->enabledPlugins.contains(plugin)) {
+                    d->enabledPlugins.removeAll(plugin);
+                    QHash<QString, QmlDebugServerPlugin *>::Iterator iter = 
+                        d->plugins.find(plugin);
+                    if (iter != d->plugins.end())
+                        (*iter)->enabledChanged(false);
+                }
+            } else {
+                qWarning("QmlDebugServer: Invalid control message %d", op);
+            }
+
+        } else {
+            QByteArray message;
+            pack >> message;
+
+            QHash<QString, QmlDebugServerPlugin *>::Iterator iter = 
+                d->plugins.find(name);
+            if (iter == d->plugins.end()) {
+                qWarning() << "QmlDebugServer: Message received for missing plugin" << name;
+            } else {
+                (*iter)->messageReceived(message);
+            }
+        }
+    }
+}
+
+QmlDebugServerPluginPrivate::QmlDebugServerPluginPrivate()
+: server(0)
+{
+}
+
+QmlDebugServerPlugin::QmlDebugServerPlugin(const QString &name, QObject *parent)
+: QObject(*(new QmlDebugServerPluginPrivate), parent)
+{
+    Q_D(QmlDebugServerPlugin);
+    d->name = name;
+    d->server = QmlDebugServer::instance();
+
+    if (!d->server)
+        return;
+
+    if (d->server->d_func()->plugins.contains(name)) {
+        qWarning() << "QmlDebugServerPlugin: Conflicting plugin name" << name;
+        d->server = 0;
+    } else {
+        d->server->d_func()->plugins.insert(name, this);
+    }
+}
+
+QString QmlDebugServerPlugin::name() const
+{
+    Q_D(const QmlDebugServerPlugin);
+    return d->name;
+}
+
+bool QmlDebugServerPlugin::isEnabled() const
+{
+    Q_D(const QmlDebugServerPlugin);
+    return (d->server && d->server->d_func()->enabledPlugins.contains(d->name));
+}
+
+bool QmlDebugServerPlugin::isDebuggingEnabled()
+{
+    return QmlDebugServer::instance() != 0;
+}
+
+void QmlDebugServerPlugin::sendMessage(const QByteArray &message)
+{
+    Q_D(QmlDebugServerPlugin);
+
+    if (!d->server || !d->server->d_func()->connection)
+        return;
+
+    QPacket pack;
+    pack << d->name << message;
+    d->server->d_func()->protocol->send(pack);
+}
+
+void QmlDebugServerPlugin::enabledChanged(bool)
+{
+}
+
+void QmlDebugServerPlugin::messageReceived(const QByteArray &)
+{
+}
+
+#include "qmldebugserver.moc"
+
+QT_END_NAMESPACE
diff --git a/src/declarative/debugger/qmldebugserver.h b/src/declarative/debugger/qmldebugserver.h
new file mode 100644
index 0000000..8ee2cfb
--- /dev/null
+++ b/src/declarative/debugger/qmldebugserver.h
@@ -0,0 +1,81 @@
+/****************************************************************************
+**
+** Copyright (C) 2009 Nokia Corporation and/or its subsidiary(-ies).
+** Contact: Qt Software Information (qt-info@nokia.com)
+**
+** This file is part of the QtDeclarative module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** No Commercial Usage
+** This file contains pre-release code and may not be distributed.
+** You may use this file in accordance with the terms and conditions
+** contained in the either Technology Preview License Agreement or the
+** Beta Release License Agreement.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 2.1 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL included in the
+** packaging of this file.  Please review the following information to
+** ensure the GNU Lesser General Public License version 2.1 requirements
+** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
+**
+** In addition, as a special exception, Nokia gives you certain
+** additional rights. These rights are described in the Nokia Qt LGPL
+** Exception version 1.0, included in the file LGPL_EXCEPTION.txt in this
+** package.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 3.0 as published by the Free Software
+** Foundation and appearing in the file LICENSE.GPL included in the
+** packaging of this file.  Please review the following information to
+** ensure the GNU General Public License version 3.0 requirements will be
+** met: http://www.gnu.org/copyleft/gpl.html.
+**
+** If you are unsure which license is appropriate for your use, please
+** contact the sales department at qt-sales@nokia.com.
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#ifndef QMLDEBUGSERVER_H
+#define QMLDEBUGSERVER_H
+
+#include <QtCore/qobject.h>
+
+QT_BEGIN_HEADER
+
+QT_BEGIN_NAMESPACE
+
+class QmlDebugServerPluginPrivate;
+class QmlDebugServerPlugin : public QObject
+{
+    Q_OBJECT
+    Q_DECLARE_PRIVATE(QmlDebugServerPlugin)
+    Q_DISABLE_COPY(QmlDebugServerPlugin)
+public:
+    QmlDebugServerPlugin(const QString &, QObject *parent = 0);
+
+    QString name() const;
+
+    bool isEnabled() const;
+
+    void sendMessage(const QByteArray &);
+
+    static bool isDebuggingEnabled();
+
+protected:
+    virtual void enabledChanged(bool);
+    virtual void messageReceived(const QByteArray &);
+
+private:
+    friend class QmlDebugServer;
+};
+
+QT_END_NAMESPACE
+
+QT_END_HEADER
+
+#endif // QMLDEBUGSERVER_H
+
diff --git a/src/declarative/debugger/qpacketprotocol.cpp b/src/declarative/debugger/qpacketprotocol.cpp
new file mode 100644
index 0000000..6911b89
--- /dev/null
+++ b/src/declarative/debugger/qpacketprotocol.cpp
@@ -0,0 +1,462 @@
+/****************************************************************************
+**
+** This file is part of the $PACKAGE_NAME$.
+**
+** Copyright (C) $THISYEAR$ $COMPANY_NAME$.
+**
+** $QT_EXTENDED_DUAL_LICENSE$
+**
+****************************************************************************/
+
+#include "qpacketprotocol.h"
+#include <QBuffer>
+
+#define MAX_PACKET_SIZE 0x7FFFFFFF
+
+/*!
+  \class QPacketProtocol
+
+  \brief The QPacketProtocol class encapsulates communicating discrete packets
+  across fragmented IO channels, such as TCP sockets.
+
+  QPacketProtocol makes it simple to send arbitrary sized data "packets" across 
+  fragmented transports such as TCP and UDP.
+
+  As transmission boundaries are not respected, sending packets over protocols
+  like TCP frequently involves "stitching" them back together at the receiver.
+  QPacketProtocol makes this easier by performing this task for you.  Packet
+  data sent using QPacketProtocol is prepended with a 4-byte size header
+  allowing the receiving QPacketProtocol to buffer the packet internally until
+  it has all been received.  QPacketProtocol does not perform any sanity
+  checking on the size or on the data, so this class should only be used in
+  prototyping or trusted situations where DOS attacks are unlikely.
+
+  QPacketProtocol does not perform any communications itself.  Instead it can
+  operate on any QIODevice that supports the QIODevice::readyRead() signal.  A
+  logical "packet" is encapsulated by the companion QPacket class.  The
+  following example shows two ways to send data using QPacketProtocol.  The
+  transmitted data is equivalent in both.
+
+  \code
+  QTcpSocket socket;
+  // ... connect socket ...
+
+  QPacketProtocol protocol(&socket);
+
+  // Send packet the quick way
+  protocol.send() << "Hello world" << 123;
+
+  // Send packet the longer way
+  QPacket packet;
+  packet << "Hello world" << 123;
+  protocol.send(packet);
+  \endcode
+
+  Likewise, the following shows how to read data from QPacketProtocol, assuming
+  that the QPacketProtocol::readyRead() signal has been emitted.
+
+  \code
+  // ... QPacketProtocol::readyRead() is emitted ...
+
+  int a;
+  QByteArray b;
+
+  // Receive packet the quick way
+  protocol.read() >> a >> b;
+
+  // Receive packet the longer way
+  QPacket packet = protocol.read();
+  p >> a >> b;
+  \endcode
+
+  \ingroup io
+  \sa QPacket
+*/
+
+class QPacketProtocolPrivate : public QObject
+{
+Q_OBJECT
+public:
+    QPacketProtocolPrivate(QPacketProtocol * parent, QIODevice * _dev)
+    : QObject(parent), inProgressSize(-1), maxPacketSize(MAX_PACKET_SIZE),
+      dev(_dev)
+    {
+        Q_ASSERT(4 == sizeof(qint32));
+
+        QObject::connect(this, SIGNAL(readyRead()),
+                         parent, SIGNAL(readyRead()));
+        QObject::connect(this, SIGNAL(packetWritten()),
+                         parent, SIGNAL(packetWritten()));
+        QObject::connect(this, SIGNAL(invalidPacket()),
+                         parent, SIGNAL(invalidPacket()));
+        QObject::connect(dev, SIGNAL(readyRead()),
+                         this, SLOT(readyToRead()));
+        QObject::connect(dev, SIGNAL(aboutToClose()),
+                         this, SLOT(aboutToClose()));
+        QObject::connect(dev, SIGNAL(bytesWritten(qint64)),
+                         this, SLOT(bytesWritten(qint64)));
+    }
+
+signals:
+    void readyRead();
+    void packetWritten();
+    void invalidPacket();
+
+public slots:
+    void aboutToClose()
+    {
+        inProgress.clear();
+        sendingPackets.clear();
+        inProgressSize = -1;
+    }
+
+    void bytesWritten(qint64 bytes)
+    {
+        Q_ASSERT(!sendingPackets.isEmpty());
+
+        while(bytes) {
+            if(sendingPackets.at(0) > bytes) {
+                sendingPackets[0] -= bytes;
+                bytes = 0;
+            } else {
+                bytes -= sendingPackets.at(0);
+                sendingPackets.removeFirst();
+                emit packetWritten();
+            }
+        }
+    }
+
+    void readyToRead()
+    {
+        if(-1 == inProgressSize) {
+            // We need a size header of sizeof(qint32)
+            if(sizeof(qint32) > dev->bytesAvailable())
+                return;
+
+            // Read size header
+            int read = dev->read((char *)&inProgressSize, sizeof(qint32));
+            Q_ASSERT(read == sizeof(qint32));
+            Q_UNUSED(read);
+
+            // Check sizing constraints
+            if(inProgressSize > maxPacketSize) {
+                QObject::disconnect(dev, SIGNAL(readyRead()),
+                                    this, SLOT(readyToRead()));
+                QObject::disconnect(dev, SIGNAL(aboutToClose()),
+                                    this, SLOT(aboutToClose()));
+                QObject::disconnect(dev, SIGNAL(bytesWritten(qint64)),
+                                    this, SLOT(bytesWritten(qint64)));
+                dev = 0;
+                emit invalidPacket();
+                return;
+            }
+
+            inProgressSize -= sizeof(qint32);
+
+            // Need to get trailing data
+            readyToRead();
+        } else {
+            inProgress.append(dev->read(inProgressSize - inProgress.size()));
+
+            if(inProgressSize == inProgress.size()) {
+                // Packet has arrived!
+                packets.append(inProgress);
+                inProgressSize = -1;
+                inProgress.clear();
+
+                emit readyRead();
+
+                // Need to get trailing data
+                readyToRead();
+            }
+        }
+    }
+
+public:
+    QList<qint64> sendingPackets;
+    QList<QByteArray> packets;
+    QByteArray inProgress;
+    qint32 inProgressSize;
+    qint32 maxPacketSize;
+    QIODevice * dev;
+};
+
+/*!
+  Construct a QPacketProtocol instance that works on \a dev with the
+  specified \a parent.
+ */
+QPacketProtocol::QPacketProtocol(QIODevice * dev, QObject * parent)
+: QObject(parent), d(new QPacketProtocolPrivate(this, dev))
+{
+    Q_ASSERT(dev);
+}
+
+/*!
+  Destroys the QPacketProtocol instance.
+ */
+QPacketProtocol::~QPacketProtocol()
+{
+}
+
+/*!
+  Returns the maximum packet size allowed.  By default this is
+  2,147,483,647 bytes.  
+  
+  If a packet claiming to be larger than the maximum packet size is received,
+  the QPacketProtocol::invalidPacket() signal is emitted.
+
+  \sa QPacketProtocol::setMaximumPacketSize()
+ */
+qint32 QPacketProtocol::maximumPacketSize() const
+{
+    return d->maxPacketSize;
+}
+
+/*!
+  Sets the maximum allowable packet size to \a max.
+
+  \sa QPacketProtocol::maximumPacketSize()
+ */
+qint32 QPacketProtocol::setMaximumPacketSize(qint32 max)
+{
+    if(max > (signed)sizeof(qint32))
+        d->maxPacketSize = max;
+    return d->maxPacketSize;
+}
+
+/*!
+  Returns a streamable object that is transmitted on destruction.  For example
+
+  \code
+  protocol.send() << "Hello world" << 123;
+  \endcode
+
+  will send a packet containing "Hello world" and 123.  To construct more 
+  complex packets, explicitly construct a QPacket instance.
+ */
+QPacketAutoSend QPacketProtocol::send()
+{
+    return QPacketAutoSend(this);
+}
+
+/*!
+  \fn void QPacketProtocol::send(const QPacket & packet)
+
+  Transmit the \a packet.
+ */
+void QPacketProtocol::send(const QPacket & p)
+{
+    if(p.b.isEmpty())
+        return; // We don't send empty packets
+
+    qint64 sendSize = p.b.size() + sizeof(qint32);
+
+    d->sendingPackets.append(sendSize);
+    qint32 sendSize32 = sendSize;
+    qint64 writeBytes = d->dev->write((char *)&sendSize32, sizeof(qint32));
+    Q_ASSERT(writeBytes == sizeof(qint32));
+    writeBytes = d->dev->write(p.b);
+    Q_ASSERT(writeBytes == p.b.size());
+}
+
+/*!
+  Returns the number of received packets yet to be read.
+  */
+qint64 QPacketProtocol::packetsAvailable() const
+{
+    return d->packets.count();
+}
+
+/*!
+  Discard any unread packets.
+  */
+void QPacketProtocol::clear()
+{
+    d->packets.clear();
+}
+
+/*!
+  Return the next unread packet, or an invalid QPacket instance if no packets
+  are available.  This method does NOT block.
+  */
+QPacket QPacketProtocol::read()
+{
+    if(0 == d->packets.count())
+        return QPacket();
+
+    QPacket rv(d->packets.at(0));
+    d->packets.removeFirst();
+    return rv;
+}
+
+/*!
+  Return the QIODevice passed to the QPacketProtocol constructor.
+*/
+QIODevice * QPacketProtocol::device()
+{
+    return d->dev;
+}
+
+/*!
+  \fn void QPacketProtocol::readyRead()
+
+  Emitted whenever a new packet is received.  Applications may use
+  QPacketProtocol::read() to retrieve this packet.
+ */
+
+/*!
+  \fn void QPacketProtocol::invalidPacket()
+
+  A packet larger than the maximum allowable packet size was received.  The
+  packet will be discarded and, as it indicates corruption in the protocol, no
+  further packets will be received.
+ */
+
+/*!
+  \fn void QPacketProtocol::packetWritten()
+
+  Emitted each time a packet is completing written to the device.  This signal
+  may be used for communications flow control.
+ */
+
+/*!
+  \class QPacket
+    \inpublicgroup QtBaseModule
+
+  \brief The QPacket class encapsulates an unfragmentable packet of data to be
+  transmitted by QPacketProtocol.
+
+  The QPacket class works together with QPacketProtocol to make it simple to
+  send arbitrary sized data "packets" across fragmented transports such as TCP
+  and UDP.
+
+  QPacket provides a QDataStream interface to an unfragmentable packet.
+  Applications should construct a QPacket, propagate it with data and then
+  transmit it over a QPacketProtocol instance.  For example:
+  \code
+  QPacketProtocol protocol(...);
+
+  QPacket myPacket;
+  myPacket << "Hello world!" << 123;
+  protocol.send(myPacket);
+  \endcode
+
+  As long as both ends of the connection are using the QPacketProtocol class,
+  the data within this packet will be delivered unfragmented at the other end,
+  ready for extraction.
+
+  \code
+  QByteArray greeting;
+  int count;
+
+  QPacket myPacket = protocol.read();
+
+  myPacket >> greeting >> count;
+  \endcode
+
+  Only packets returned from QPacketProtocol::read() may be read from.  QPacket
+  instances constructed by directly by applications are for transmission only 
+  and are considered "write only".  Attempting to read data from them will 
+  result in undefined behaviour.
+
+  \ingroup io
+  \sa QPacketProtocol
+ */
+
+/*!
+  Constructs an empty write-only packet.
+  */
+QPacket::QPacket()
+: QDataStream(), buf(0)
+{
+    buf = new QBuffer(&b);
+    buf->open(QIODevice::WriteOnly);
+    setDevice(buf);
+}
+
+/*!
+  Destroys the QPacket instance.
+  */
+QPacket::~QPacket()
+{
+    if(buf) {
+        delete buf;
+        buf = 0;
+    }
+}
+
+/*!
+  Creates a copy of \a other.  The initial stream positions are shared, but the
+  two packets are otherwise independant.
+ */
+QPacket::QPacket(const QPacket & other)
+: QDataStream(), b(other.b), buf(0)
+{
+    buf = new QBuffer(&b);
+    buf->open(other.buf->openMode());
+    setDevice(buf);
+}
+
+/*!
+  \internal
+  */
+QPacket::QPacket(const QByteArray & ba)
+: QDataStream(), b(ba), buf(0)
+{
+    buf = new QBuffer(&b);
+    buf->open(QIODevice::ReadOnly);
+    setDevice(buf);
+}
+
+/*!
+  Returns true if this packet is empty - that is, contains no data.
+  */
+bool QPacket::isEmpty() const
+{
+    return b.isEmpty();
+}
+
+/*!
+  Clears data in the packet.  This is useful for reusing one writable packet.
+  For example
+  \code
+  QPacketProtocol protocol(...);
+
+  QPacket packet;
+
+  packet << "Hello world!" << 123;
+  protocol.send(packet);
+
+  packet.clear();
+  packet << "Goodbyte world!" << 789;
+  protocol.send(packet);
+  \endcode
+ */
+void QPacket::clear()
+{
+    QBuffer::OpenMode oldMode = buf->openMode();
+    buf->close();
+    b.clear();
+    buf->setBuffer(&b); // reset QBuffer internals with new size of b.
+    buf->open(oldMode);
+}
+
+/*!
+  \class QPacketAutoSend
+    \inpublicgroup QtBaseModule
+
+  \internal
+  */
+QPacketAutoSend::QPacketAutoSend(QPacketProtocol * _p)
+: QPacket(), p(_p)
+{
+}
+
+QPacketAutoSend::~QPacketAutoSend()
+{
+    if(!b.isEmpty())
+        p->send(*this);
+}
+
+#include "qpacketprotocol.moc"
+
diff --git a/src/declarative/debugger/qpacketprotocol.h b/src/declarative/debugger/qpacketprotocol.h
new file mode 100644
index 0000000..6dd8bda
--- /dev/null
+++ b/src/declarative/debugger/qpacketprotocol.h
@@ -0,0 +1,81 @@
+/****************************************************************************
+**
+** This file is part of the $PACKAGE_NAME$.
+**
+** Copyright (C) $THISYEAR$ $COMPANY_NAME$.
+**
+** $QT_EXTENDED_DUAL_LICENSE$
+**
+****************************************************************************/
+
+#ifndef QPACKETPROTOCOL_H
+#define QPACKETPROTOCOL_H
+
+#include <QtCore/qobject.h>
+#include <QtCore/qdatastream.h>
+
+class QIODevice;
+class QBuffer;
+class QPacket;
+class QPacketAutoSend;
+class QPacketProtocolPrivate;
+
+class Q_DECLARATIVE_EXPORT QPacketProtocol : public QObject
+{
+Q_OBJECT
+public:
+    explicit QPacketProtocol(QIODevice * dev, QObject * parent = 0);
+    virtual ~QPacketProtocol();
+
+    qint32 maximumPacketSize() const;
+    qint32 setMaximumPacketSize(qint32);
+
+    QPacketAutoSend send();
+    void send(const QPacket &);
+
+    qint64 packetsAvailable() const;
+    QPacket read();
+
+    void clear();
+
+    QIODevice * device();
+
+signals:
+    void readyRead();
+    void invalidPacket();
+    void packetWritten();
+
+private:
+    QPacketProtocolPrivate * d;
+};
+
+
+class Q_DECLARATIVE_EXPORT QPacket : public QDataStream
+{
+public:
+    QPacket();
+    QPacket(const QPacket &);
+    virtual ~QPacket();
+
+    void clear();
+    bool isEmpty() const;
+
+protected:
+    friend class QPacketProtocol;
+    QPacket(const QByteArray & ba);
+    QByteArray b;
+    QBuffer * buf;
+};
+
+class Q_DECLARATIVE_EXPORT QPacketAutoSend : public QPacket
+{
+public:
+    virtual ~QPacketAutoSend();
+
+private:
+    friend class QPacketProtocol;
+    QPacketAutoSend(QPacketProtocol *);
+    QPacketProtocol * p;
+};
+
+#endif