Add DBus VirtualObject to handle multiple paths.

When a virtual object is registered with the SubPath option
it will handle all dbus calls to itself and all child paths.
It needs to reimplement handleMessage for that purpose.

Introspection needs to be implemented manually in the introspect function.

Reviewed-by: Thiago Macieira <thiago.macieira@nokia.com>

8 files changed, 284 insertions, 10 deletions

diff --git a/src/dbus/dbus.pro b/src/dbus/dbus.pro
index 08c9ea1..d21b380 100644
--- a/src/dbus/dbus.pro
+++ b/src/dbus/dbus.pro
@@ -44,7 +44,8 @@ PUB_HEADERS = qdbusargument.h \
     qdbusmetatype.h \
     qdbuspendingcall.h \
     qdbuspendingreply.h \
-    qdbuscontext.h
+    qdbuscontext.h \
+    qdbusvirtualobject.h
 HEADERS += $$PUB_HEADERS \
     qdbusconnection_p.h \
     qdbusmessage_p.h \
@@ -60,7 +61,8 @@ HEADERS += $$PUB_HEADERS \
     qdbuspendingcall_p.h \
     qdbus_symbols_p.h \
     qdbusservicewatcher.h \
-    qdbusunixfiledescriptor.h
+    qdbusunixfiledescriptor.h \
+    qdbusvirtualobject.h
 SOURCES += qdbusconnection.cpp \
     qdbusconnectioninterface.cpp \
     qdbuserror.cpp \
@@ -87,4 +89,5 @@ SOURCES += qdbusconnection.cpp \
     qdbuspendingreply.cpp \
     qdbus_symbols.cpp \
     qdbusservicewatcher.cpp \
-    qdbusunixfiledescriptor.cpp
+    qdbusunixfiledescriptor.cpp \
+    qdbusvirtualobject.cpp
diff --git a/src/dbus/qdbusconnection.cpp b/src/dbus/qdbusconnection.cpp
index 0b4133c..e524103 100644
--- a/src/dbus/qdbusconnection.cpp
+++ b/src/dbus/qdbusconnection.cpp
@@ -222,6 +222,18 @@ void QDBusConnectionManager::setConnection(const QString &name, QDBusConnectionP
 */
 
 /*!
+    \internal
+    \since 4.8
+    \enum QDBusConnection::VirtualObjectRegisterOption
+    Specifies the options for registering virtual objects with the connection. The possible values are:
+
+    \value SingleNode                           register a virtual object to handle one path only
+    \value SubPath                              register a virtual object so that it handles all sub paths
+
+    \sa registerVirtualObject(), QDBusVirtualObject
+*/
+
+/*!
     \enum QDBusConnection::UnregisterMode
     The mode for unregistering an object path:
 
@@ -801,9 +813,21 @@ bool QDBusConnection::registerObject(const QString &path, QObject *object, Regis
             // this node exists
             // consider it free if there's no object here and the user is not trying to
             // replace the object sub-tree
-            if ((options & ExportChildObjects && !node->children.isEmpty()) || node->obj)
+            if (node->obj)
                 return false;
 
+            if (options & QDBusConnectionPrivate::VirtualObject) {
+                // technically the check for children needs to go even deeper
+                if (options & SubPath) {
+                    foreach (const QDBusConnectionPrivate::ObjectTreeNode &child, node->children) {
+                        if (child.obj)
+                            return false;
+                    }
+                }
+            } else {
+                if ((options & ExportChildObjects && !node->children.isEmpty()))
+                    return false;
+            }
             // we can add the object here
             node->obj = object;
             node->flags = options;
@@ -813,6 +837,13 @@ bool QDBusConnection::registerObject(const QString &path, QObject *object, Regis
             return true;
         }
 
+        // if a virtual object occupies this path, return false
+        if (node->obj && (node->flags & QDBusConnectionPrivate::VirtualObject) && (node->flags & QDBusConnection::SubPath)) {
+            qDebug("Cannot register object at %s because QDBusVirtualObject handles all sub-paths.",
+                   qPrintable(path));
+            return false;
+        }
+
         // find the position where we'd insert the node
         QDBusConnectionPrivate::ObjectTreeNode::DataList::Iterator it =
             qLowerBound(node->children.begin(), node->children.end(), pathComponents.at(i));
@@ -841,6 +872,21 @@ bool QDBusConnection::registerObject(const QString &path, QObject *object, Regis
 }
 
 /*!
+    \internal
+    \since 4.8
+    Registers a QDBusTreeNode for a path. It can handle a path including all child paths, thus
+    handling multiple DBus nodes.
+
+    To unregister a QDBusTreeNode use the unregisterObject() function with its path.
+*/
+bool QDBusConnection::registerVirtualObject(const QString &path, QDBusVirtualObject *treeNode,
+                      VirtualObjectRegisterOption options)
+{
+    int opts = options | QDBusConnectionPrivate::VirtualObject;
+    return registerObject(path, (QObject*) treeNode, (RegisterOptions) opts);
+}
+
+/*!
     Unregisters an object that was registered with the registerObject() at the object path given by
     \a path and, if \a mode is QDBusConnection::UnregisterTree, all of its sub-objects too.
 
@@ -905,6 +951,8 @@ QObject *QDBusConnection::objectRegisteredAt(const QString &path) const
     while (node) {
         if (pathComponents.count() == i)
             return node->obj;
+        if ((node->flags & QDBusConnectionPrivate::VirtualObject) && (node->flags & QDBusConnection::SubPath))
+            return node->obj;
 
         QDBusConnectionPrivate::ObjectTreeNode::DataList::ConstIterator it =
             qLowerBound(node->children.constBegin(), node->children.constEnd(), pathComponents.at(i));
@@ -917,6 +965,8 @@ QObject *QDBusConnection::objectRegisteredAt(const QString &path) const
     return 0;
 }
 
+
+
 /*!
     Returns a QDBusConnectionInterface object that represents the
     D-Bus server interface on this connection.
diff --git a/src/dbus/qdbusconnection.h b/src/dbus/qdbusconnection.h
index 4bdd055..8b126af 100644
--- a/src/dbus/qdbusconnection.h
+++ b/src/dbus/qdbusconnection.h
@@ -69,6 +69,7 @@ class QDBusError;
 class QDBusMessage;
 class QDBusPendingCall;
 class QDBusConnectionInterface;
+class QDBusVirtualObject;
 class QObject;
 
 class QDBusConnectionPrivate;
@@ -104,8 +105,8 @@ public:
         // Qt 4.2 had a misspelling here
         ExportAllSignal = ExportAllSignals,
 #endif
-
         ExportChildObjects = 0x1000
+        // Reserved = 0xff000000
     };
     enum UnregisterMode {
         UnregisterNode,
@@ -113,6 +114,15 @@ public:
     };
     Q_DECLARE_FLAGS(RegisterOptions, RegisterOption)
 
+    enum VirtualObjectRegisterOption {
+        SingleNode = 0x0,
+        SubPath = 0x1
+        // Reserved = 0xff000000
+    };
+#ifndef Q_QDOC
+    Q_DECLARE_FLAGS(VirtualObjectRegisterOptions, VirtualObjectRegisterOption)
+#endif
+
     enum ConnectionCapability {
         UnixFileDescriptorPassing = 0x0001
     };
@@ -163,6 +173,9 @@ public:
     void unregisterObject(const QString &path, UnregisterMode mode = UnregisterNode);
     QObject *objectRegisteredAt(const QString &path) const;
 
+    bool registerVirtualObject(const QString &path, QDBusVirtualObject *object,
+                          VirtualObjectRegisterOption options = SingleNode);
+
     bool registerService(const QString &serviceName);
     bool unregisterService(const QString &serviceName);
 
@@ -192,6 +205,7 @@ private:
 };
 
 Q_DECLARE_OPERATORS_FOR_FLAGS(QDBusConnection::RegisterOptions)
+Q_DECLARE_OPERATORS_FOR_FLAGS(QDBusConnection::VirtualObjectRegisterOptions)
 
 QT_END_NAMESPACE
 
diff --git a/src/dbus/qdbusconnection_p.h b/src/dbus/qdbusconnection_p.h
index 12bcb21..d481cf1 100644
--- a/src/dbus/qdbusconnection_p.h
+++ b/src/dbus/qdbusconnection_p.h
@@ -129,6 +129,11 @@ public:
         QByteArray matchRule;
     };
 
+    enum TreeNodeType {
+        Object = 0x0,
+        VirtualObject = 0x01000000
+    };
+
     struct ObjectTreeNode
     {
         typedef QVector<ObjectTreeNode> DataList;
@@ -143,8 +148,12 @@ public:
             { return QStringRef(&name) < other; }
 
         QString name;
-        QObject* obj;
+        union {
+            QObject *obj;
+            QDBusVirtualObject *treeNode;
+        };
         int flags;
+
         DataList children;
     };
 
@@ -333,7 +342,7 @@ extern bool qDBusInterfaceInObject(QObject *obj, const QString &interface_name);
 extern QString qDBusInterfaceFromMetaObject(const QMetaObject *mo);
 
 // in qdbusinternalfilters.cpp
-extern QString qDBusIntrospectObject(const QDBusConnectionPrivate::ObjectTreeNode &node);
+extern QString qDBusIntrospectObject(const QDBusConnectionPrivate::ObjectTreeNode &node, const QString &path);
 extern QDBusMessage qDBusPropertyGet(const QDBusConnectionPrivate::ObjectTreeNode &node,
                                      const QDBusMessage &msg);
 extern QDBusMessage qDBusPropertySet(const QDBusConnectionPrivate::ObjectTreeNode &node,
diff --git a/src/dbus/qdbusintegrator.cpp b/src/dbus/qdbusintegrator.cpp
index f3f3d0b..2cde07e 100644
--- a/src/dbus/qdbusintegrator.cpp
+++ b/src/dbus/qdbusintegrator.cpp
@@ -57,6 +57,7 @@
 #include "qdbusabstractadaptor.h"
 #include "qdbusabstractadaptor_p.h"
 #include "qdbusutil_p.h"
+#include "qdbusvirtualobject.h"
 #include "qdbusmessage_p.h"
 #include "qdbuscontext_p.h"
 #include "qdbuspendingcall_p.h"
@@ -442,7 +443,11 @@ static bool findObject(const QDBusConnectionPrivate::ObjectTreeNode *root,
 
     // walk the object tree
     const QDBusConnectionPrivate::ObjectTreeNode *node = root;
-    while (start < length && node && !(node->flags & QDBusConnection::ExportChildObjects)) {
+    while (start < length && node) {
+        if (node->flags & QDBusConnection::ExportChildObjects)
+            break;
+        if ((node->flags & QDBusConnectionPrivate::VirtualObject) && (node->flags & QDBusConnection::SubPath))
+            break;
         int end = fullpath.indexOf(QLatin1Char('/'), start);
         end = (end == -1 ? length : end);
         QStringRef pathComponent(&fullpath, start, end - start);
@@ -1328,7 +1333,7 @@ bool QDBusConnectionPrivate::activateInternalFilters(const ObjectTreeNode &node,
     if (interface.isEmpty() || interface == QLatin1String(DBUS_INTERFACE_INTROSPECTABLE)) {
         if (msg.member() == QLatin1String("Introspect") && msg.signature().isEmpty()) {
             //qDebug() << "QDBusConnectionPrivate::activateInternalFilters introspect" << msg.d_ptr->msg;
-            QDBusMessage reply = msg.createReply(qDBusIntrospectObject(node));
+            QDBusMessage reply = msg.createReply(qDBusIntrospectObject(node, msg.path()));
             send(reply);
             return true;
         }
@@ -1375,6 +1380,15 @@ void QDBusConnectionPrivate::activateObject(ObjectTreeNode &node, const QDBusMes
 
     // object may be null
 
+    if (node.flags & QDBusConnectionPrivate::VirtualObject) {
+        if (node.treeNode->handleMessage(msg, q(this))) {
+            return;
+        } else {
+            if (activateInternalFilters(node, msg))
+                return;
+        }
+    }
+
     if (pathStartPos != msg.path().length()) {
         node.flags &= ~QDBusConnection::ExportAllSignals;
         node.obj = findChildObject(&node, msg.path(), pathStartPos);
diff --git a/src/dbus/qdbusinternalfilters.cpp b/src/dbus/qdbusinternalfilters.cpp
index 2b142a7..b874a64 100644
--- a/src/dbus/qdbusinternalfilters.cpp
+++ b/src/dbus/qdbusinternalfilters.cpp
@@ -56,6 +56,7 @@
 #include "qdbusmetatype_p.h"
 #include "qdbusmessage_p.h"
 #include "qdbusutil_p.h"
+#include "qdbusvirtualobject.h"
 
 #ifndef QT_NO_DBUS
 
@@ -108,7 +109,7 @@ static QString generateSubObjectXml(QObject *object)
 
 // declared as extern in qdbusconnection_p.h
 
-QString qDBusIntrospectObject(const QDBusConnectionPrivate::ObjectTreeNode &node)
+QString qDBusIntrospectObject(const QDBusConnectionPrivate::ObjectTreeNode &node, const QString &path)
 {
     // object may be null
 
@@ -155,6 +156,11 @@ QString qDBusIntrospectObject(const QDBusConnectionPrivate::ObjectTreeNode &node
             }
         }
 
+        // is it a virtual node that handles introspection itself?
+        if (node.flags & QDBusConnectionPrivate::VirtualObject) {
+            xml_data += node.treeNode->introspect(path);
+        }
+
         xml_data += QLatin1String( propertiesInterfaceXml );
     }
 
diff --git a/src/dbus/qdbusvirtualobject.cpp b/src/dbus/qdbusvirtualobject.cpp
new file mode 100644
index 0000000..f1c17b5
--- /dev/null
+++ b/src/dbus/qdbusvirtualobject.cpp
@@ -0,0 +1,97 @@
+/****************************************************************************
+**
+** Copyright (C) 2011 Nokia Corporation and/or its subsidiary(-ies).
+** All rights reserved.
+** Contact: Nokia Corporation (qt-info@nokia.com)
+**
+** This file is part of the QtDBus 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 Technology Preview License Agreement accompanying
+** this package.
+**
+** 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 1.1, included in the file LGPL_EXCEPTION.txt in this package.
+**
+** If you have questions regarding the use of this file, please contact
+** Nokia at qt-info@nokia.com.
+**
+**
+**
+**
+**
+**
+**
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#include "qdbusvirtualobject.h"
+
+#ifndef QT_NO_DBUS
+
+QT_BEGIN_NAMESPACE
+
+QDBusVirtualObject::QDBusVirtualObject(QObject *parent) :
+    QObject(parent)
+{
+}
+
+QDBusVirtualObject::~QDBusVirtualObject()
+{
+}
+
+QT_END_NAMESPACE
+
+
+/*!
+    \internal
+    \class QDBusVirtualObject
+    \inmodule QtDBus
+    \since 4.8
+
+    \brief The QDBusVirtualObject class is used to handle several DBus paths with one class.
+*/
+
+/*!
+    \internal
+    \fn bool QDBusVirtualObject::handleMessage(const QDBusMessage &message, const QDBusConnection &connection) = 0
+
+    This function needs to handle all messages to the path of the
+    virtual object, when the SubPath option is specified.
+    The service, path, interface and methos are all part of the message.
+    Must return true when the message is handled, otherwise false (will generate dbus error message).
+*/
+
+
+/*!
+    \internal
+    \fn QString QDBusVirtualObject::introspect(const QString &path) const
+
+    This function needs to handle the introspection of the
+    virtual object. It must return xml of the form:
+
+    \code
+<interface name="com.trolltech.QtDBus.MyObject" >
+    <property access="readwrite" type="i" name="prop1" />
+</interface>
+    \endcode
+
+    If you pass the SubPath option, this introspection has to include all child nodes.
+    Otherwise QDBus handles the introspection of the child nodes.
+*/
+
+#endif // QT_NO_DBUS
diff --git a/src/dbus/qdbusvirtualobject.h b/src/dbus/qdbusvirtualobject.h
new file mode 100644
index 0000000..e51dca5
--- /dev/null
+++ b/src/dbus/qdbusvirtualobject.h
@@ -0,0 +1,81 @@
+/****************************************************************************
+**
+** Copyright (C) 2011 Nokia Corporation and/or its subsidiary(-ies).
+** All rights reserved.
+** Contact: Nokia Corporation (qt-info@nokia.com)
+**
+** This file is part of the QtDBus 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 Technology Preview License Agreement accompanying
+** this package.
+**
+** 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 1.1, included in the file LGPL_EXCEPTION.txt in this package.
+**
+** If you have questions regarding the use of this file, please contact
+** Nokia at qt-info@nokia.com.
+**
+**
+**
+**
+**
+**
+**
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#ifndef QDBUSTREENODE_H
+#define QDBUSTREENODE_H
+
+#include <QtDBus/qdbusmacros.h>
+#include <QtCore/qstring.h>
+#include <QtCore/qobject.h>
+
+#ifndef QT_NO_DBUS
+
+QT_BEGIN_HEADER
+
+QT_BEGIN_NAMESPACE
+
+QT_MODULE(DBus)
+
+class QDBusMessage;
+class QDBusConnection;
+
+class QDBusVirtualObjectPrivate;
+class Q_DBUS_EXPORT QDBusVirtualObject : public QObject
+{
+    Q_OBJECT
+public:
+    explicit QDBusVirtualObject(QObject *parent = 0);
+    virtual ~QDBusVirtualObject();
+
+    virtual QString introspect(const QString &path) const = 0;
+    virtual bool handleMessage(const QDBusMessage &message, const QDBusConnection &connection) = 0;
+
+private:
+    Q_DECLARE_PRIVATE(QDBusVirtualObject)
+    Q_DISABLE_COPY(QDBusVirtualObject)
+};
+
+QT_END_NAMESPACE
+
+QT_END_HEADER
+
+#endif // QT_NO_DBUS
+#endif