Assistant: Encapsulate accesses to help engine.

Reviewed-by: kh1

26 files changed, 1224 insertions, 772 deletions

diff --git a/tools/assistant/tools/assistant/assistant.pro b/tools/assistant/tools/assistant/assistant.pro
index 81677c3..ca2e52e 100644
--- a/tools/assistant/tools/assistant/assistant.pro
+++ b/tools/assistant/tools/assistant/assistant.pro
@@ -31,7 +31,9 @@ HEADERS += helpviewer.h \
     aboutdialog.h \
     qtdocinstaller.h \
     xbelsupport.h \
-    ../shared/collectionconfiguration.h
+    ../shared/collectionconfiguration.h \
+    helpenginewrapper.h \
+    tracer.h
 win32:HEADERS += remotecontrol_win.h
 SOURCES += helpviewer.cpp \
     main.cpp \
@@ -50,7 +52,8 @@ SOURCES += helpviewer.cpp \
     aboutdialog.cpp \
     qtdocinstaller.cpp \
     xbelsupport.cpp \
-    ../shared/collectionconfiguration.cpp
+    ../shared/collectionconfiguration.cpp \
+    helpenginewrapper.cpp
 FORMS += topicchooser.ui \
     preferencesdialog.ui \
     filternamedialog.ui \
diff --git a/tools/assistant/tools/assistant/bookmarkmanager.cpp b/tools/assistant/tools/assistant/bookmarkmanager.cpp
index 3c473d7..f8cad4d 100644
--- a/tools/assistant/tools/assistant/bookmarkmanager.cpp
+++ b/tools/assistant/tools/assistant/bookmarkmanager.cpp
@@ -41,7 +41,7 @@
 
 #include "bookmarkmanager.h"
 #include "centralwidget.h"
-#include "../shared/collectionconfiguration.h"
+#include "helpenginewrapper.h"
 
 #include <QtGui/QMenu>
 #include <QtGui/QIcon>
@@ -57,7 +57,6 @@
 #include <QtGui/QToolButton>
 #include <QtGui/QPushButton>
 #include <QtGui/QApplication>
-#include <QtHelp/QHelpEngineCore>
 #include <QtGui/QDialogButtonBox>
 #include <QtGui/QSortFilterProxyModel>
 
@@ -624,11 +623,10 @@ Qt::ItemFlags BookmarkModel::flags(const QModelIndex &index) const
 // BookmarkManager
 
 
-BookmarkManager::BookmarkManager(QHelpEngineCore *_helpEngine)
+BookmarkManager::BookmarkManager()
     : treeModel(new BookmarkModel(0, 1, this))
     , listModel(new BookmarkModel(0, 1, this))
     , renameItem(0)
-    , helpEngine(_helpEngine)
 {
     folderIcon = QApplication::style()->standardIcon(QStyle::SP_DirClosedIcon);
     bookmarkIcon = QIcon(QLatin1String(":/trolltech/assistant/images/bookmark.png"));
@@ -663,7 +661,7 @@ void BookmarkManager::saveBookmarks()
     QDataStream stream(&bookmarks, QIODevice::WriteOnly);
 
     readBookmarksRecursive(treeModel->invisibleRootItem(), stream, 0);
-    CollectionConfiguration::setBookmarks(*helpEngine, bookmarks);
+    HelpEngineWrapper::instance().setBookmarks(bookmarks);
 }
 
 QStringList BookmarkManager::bookmarkFolders() const
@@ -815,7 +813,7 @@ void BookmarkManager::setupBookmarkModels()
     QList<int> lastDepths;
     QList<QStandardItem*> parents;
 
-    QByteArray ba = CollectionConfiguration::bookmarks(*helpEngine);
+    QByteArray ba = HelpEngineWrapper::instance().bookmarks();
     QDataStream stream(ba);
     while (!stream.atEnd()) {
         stream >> depth >> name >> type >> expanded;
diff --git a/tools/assistant/tools/assistant/bookmarkmanager.h b/tools/assistant/tools/assistant/bookmarkmanager.h
index c6be134..13d4b5c 100644
--- a/tools/assistant/tools/assistant/bookmarkmanager.h
+++ b/tools/assistant/tools/assistant/bookmarkmanager.h
@@ -168,7 +168,7 @@ class BookmarkManager : public QObject
     Q_OBJECT
 
 public:
-    BookmarkManager(QHelpEngineCore* helpEngine);
+    BookmarkManager();
     ~BookmarkManager();
 
     BookmarkModel* treeBookmarkModel();
@@ -208,7 +208,6 @@ private:
     BookmarkModel *treeModel;
     BookmarkModel *listModel;
     QStandardItem *renameItem;
-    QHelpEngineCore *helpEngine;
     QMap<QAction*, QModelIndex> map;
 };
 
diff --git a/tools/assistant/tools/assistant/centralwidget.cpp b/tools/assistant/tools/assistant/centralwidget.cpp
index d1cccc1..df28d63 100644
--- a/tools/assistant/tools/assistant/centralwidget.cpp
+++ b/tools/assistant/tools/assistant/centralwidget.cpp
@@ -40,6 +40,7 @@
 ****************************************************************************/
 
 #include "centralwidget.h"
+#include "helpenginewrapper.h"
 #include "helpviewer.h"
 #include "searchwidget.h"
 #include "mainwindow.h"
@@ -68,7 +69,6 @@
 #include <QtGui/QPrintPreviewDialog>
 #include <QtGui/QPageSetupDialog>
 
-#include <QtHelp/QHelpEngine>
 #include <QtHelp/QHelpSearchEngine>
 
 QT_BEGIN_NAMESPACE
@@ -206,14 +206,12 @@ QToolButton* FindWidget::setupToolButton(const QString &text, const QString &ico
 // --
 
 
-CentralWidget::CentralWidget(QHelpEngine *engine, MainWindow *parent)
+CentralWidget::CentralWidget(MainWindow *parent)
     : QWidget(parent)
     , lastTabPage(0)
-    , collectionFile(engine->collectionFile())
     , findBar(0)
     , tabWidget(0)
     , findWidget(0)
-    , helpEngine(engine)
     , printer(0)
     , usesDefaultCollection(parent->usesDefaultCollection())
     , m_searchWidget(0)
@@ -293,10 +291,6 @@ CentralWidget::~CentralWidget()
     delete printer;
 #endif
 
-    QHelpEngineCore engine(collectionFile, 0);
-    if (!engine.setupData())
-        return;
-
     QStringList zoomFactors;
     QStringList currentPages;
     bool searchAttached = m_searchWidget->isAttached();
@@ -310,10 +304,11 @@ CentralWidget::~CentralWidget()
         }
     }
 
-    CollectionConfiguration::setLastTabPage(engine, lastTabPage);
-    CollectionConfiguration::setLastShownPages(engine, currentPages);
-    CollectionConfiguration::setSearchWasAttached(engine, searchAttached);
-    CollectionConfiguration::setLastZoomFactors(engine, zoomFactors);
+    HelpEngineWrapper &helpEngine = HelpEngineWrapper::instance();
+    helpEngine.setLastTabPage(lastTabPage);
+    helpEngine.setLastShownPages(currentPages);
+    helpEngine.setSearchWasAttached(searchAttached);
+    helpEngine.setLastZoomFactors(zoomFactors);
 }
 
 CentralWidget *CentralWidget::instance()
@@ -405,7 +400,7 @@ void CentralWidget::setSource(const QUrl &url)
         qobject_cast<HelpViewer*>(tabWidget->widget(lastTabPage));
 
     if (!viewer && !lastViewer) {
-        viewer = new HelpViewer(helpEngine, this);
+        viewer = new HelpViewer(this);
         viewer->installEventFilter(this);
         lastTabPage = tabWidget->addTab(viewer, QString());
         tabWidget->setCurrentIndex(lastTabPage);
@@ -423,16 +418,13 @@ void CentralWidget::setSource(const QUrl &url)
 
 void CentralWidget::setupWidget()
 {
-    int option = CollectionConfiguration::startOption(*helpEngine);
+    HelpEngineWrapper &helpEngine = HelpEngineWrapper::instance();
+    int option = helpEngine.startOption();
     if (option != ShowLastPages) {
         QString homePage;
-        if (option == ShowHomePage) {
-            // TODO: Can this fall-back logic go into the wrapper class?
-            homePage = CollectionConfiguration::homePage(*helpEngine);
-            if (homePage.isEmpty())
-                homePage = CollectionConfiguration::defaultHomePage(*helpEngine);
-        }
-        if (option == ShowBlankPage)
+        if (option == ShowHomePage)
+            homePage = helpEngine.homePage();
+        else if (option == ShowBlankPage)
             homePage = QLatin1String("about:blank");
         setSource(homePage);
     } else {
@@ -442,8 +434,8 @@ void CentralWidget::setupWidget()
 
 void CentralWidget::setLastShownPages()
 {
-    const QStringList lastShownPageList =
-        CollectionConfiguration::lastShownPages(*helpEngine);
+    HelpEngineWrapper &helpEngine = HelpEngineWrapper::instance();
+    const QStringList lastShownPageList = helpEngine.lastShownPages();
     const int pageCount = lastShownPageList.count();
     if (pageCount == 0) {
         if (usesDefaultCollection)
@@ -453,8 +445,7 @@ void CentralWidget::setLastShownPages()
         return;
     }
 
-    QStringList zoomFactors =
-        CollectionConfiguration::lastZoomFactors(*helpEngine);
+    QStringList zoomFactors = helpEngine.lastZoomFactors();
     while (zoomFactors.count() < pageCount)
         zoomFactors.append(CollectionConfiguration::DefaultZoomFactor);
 
@@ -463,12 +454,10 @@ void CentralWidget::setLastShownPages()
     for (; it != lastShownPageList.constEnd(); ++it, ++zIt)
         setSourceInNewTab((*it), (*zIt).toFloat());
 
-    int tab = CollectionConfiguration::lastTabPage(*helpEngine);
+    int tab = helpEngine.lastTabPage();
 
     const bool searchIsAttached = m_searchWidget->isAttached();
-    const bool searchWasAttached =
-        CollectionConfiguration::searchWasAttached(*helpEngine);
-
+    const bool searchWasAttached = helpEngine.searchWasAttached();
     if (searchWasAttached && !searchIsAttached)
         --tab;
     else if (!searchWasAttached && searchIsAttached)
@@ -639,7 +628,7 @@ void CentralWidget::setSourceInNewTab(const QUrl &url, qreal zoom)
         return;
 #endif
 
-    viewer = new HelpViewer(helpEngine, this);
+    viewer = new HelpViewer(this);
     viewer->installEventFilter(this);
     viewer->setSource(url);
     viewer->setFocus(Qt::OtherFocusReason);
@@ -663,7 +652,7 @@ void CentralWidget::setSourceInNewTab(const QUrl &url, qreal zoom)
 
 HelpViewer *CentralWidget::newEmptyTab()
 {
-    HelpViewer *viewer = new HelpViewer(helpEngine, this);
+    HelpViewer *viewer = new HelpViewer(this);
     viewer->installEventFilter(this);
     viewer->setFocus(Qt::OtherFocusReason);
 #if defined(QT_NO_WEBKIT)
@@ -1005,7 +994,7 @@ void CentralWidget::createSearchWidget(QHelpSearchEngine *searchEngine)
 void CentralWidget::activateSearchWidget(bool updateLastTabPage)
 {
     if (!m_searchWidget)
-        createSearchWidget(helpEngine->searchEngine());
+        createSearchWidget(HelpEngineWrapper::instance().searchEngine());
 
     if (!m_searchWidget->isAttached()) {
         tabWidget->insertTab(0, m_searchWidget, tr("Search"));
@@ -1072,7 +1061,8 @@ CentralWidget::highlightSearchTerms()
     if (!viewer)
         return;
 
-    QHelpSearchEngine *searchEngine = helpEngine->searchEngine();
+    QHelpSearchEngine *searchEngine =
+        HelpEngineWrapper::instance().searchEngine();
     QList<QHelpSearchQuery> queryList = searchEngine->query();
 
     QStringList terms;
@@ -1154,8 +1144,8 @@ QMap<int, QString> CentralWidget::currentSourceFileList() const
 
 void CentralWidget::getBrowserFontFor(QWidget *viewer, QFont *font)
 {
-    const QLatin1String key("useBrowserFont");
-    if (!CollectionConfiguration::usesBrowserFont(*helpEngine)) {
+    HelpEngineWrapper &helpEngine = HelpEngineWrapper::instance();
+    if (!helpEngine.usesBrowserFont()) {
         *font = qApp->font();   // case for QTextBrowser and SearchWidget
 #if !defined(QT_NO_WEBKIT)
         QWebView *view = qobject_cast<QWebView*> (viewer);
@@ -1166,7 +1156,7 @@ void CentralWidget::getBrowserFontFor(QWidget *viewer, QFont *font)
         }
 #endif
     } else {
-        *font = CollectionConfiguration::browserFont(*helpEngine);
+        *font = helpEngine.browserFont();
     }
 }
 
diff --git a/tools/assistant/tools/assistant/centralwidget.h b/tools/assistant/tools/assistant/centralwidget.h
index c348abf..d90968e 100644
--- a/tools/assistant/tools/assistant/centralwidget.h
+++ b/tools/assistant/tools/assistant/centralwidget.h
@@ -110,7 +110,7 @@ class CentralWidget : public QWidget
     Q_OBJECT
 
 public:
-    CentralWidget(QHelpEngine *engine, MainWindow *parent);
+    CentralWidget(MainWindow *parent);
     ~CentralWidget();
 
     void setupWidget();
@@ -201,13 +201,11 @@ private:
 
 private:
     int lastTabPage;
-    QString collectionFile;
     QList<QAction*> globalActionList;
 
     QWidget *findBar;
     QTabWidget *tabWidget;
     FindWidget *findWidget;
-    QHelpEngine *helpEngine;
     QPrinter *printer;
     bool usesDefaultCollection;
 
diff --git a/tools/assistant/tools/assistant/contentwindow.cpp b/tools/assistant/tools/assistant/contentwindow.cpp
index 1e3953a..17b19ba 100644
--- a/tools/assistant/tools/assistant/contentwindow.cpp
+++ b/tools/assistant/tools/assistant/contentwindow.cpp
@@ -41,22 +41,20 @@
 
 #include "contentwindow.h"
 #include "centralwidget.h"
+#include "helpenginewrapper.h"
 
 #include <QtGui/QLayout>
 #include <QtGui/QFocusEvent>
 #include <QtGui/QMenu>
 
-#include <QtHelp/QHelpEngine>
 #include <QtHelp/QHelpContentWidget>
 
 QT_BEGIN_NAMESPACE
 
-ContentWindow::ContentWindow(QHelpEngine *helpEngine)
-    : m_helpEngine(helpEngine)
-    , m_contentWidget(0)
+ContentWindow::ContentWindow()
+    : m_contentWidget(HelpEngineWrapper::instance().contentWidget())
     , m_expandDepth(-2)
 {
-    m_contentWidget = m_helpEngine->contentWidget();
     m_contentWidget->viewport()->installEventFilter(this);
     m_contentWidget->setContextMenuPolicy(Qt::CustomContextMenu);
 
diff --git a/tools/assistant/tools/assistant/contentwindow.h b/tools/assistant/tools/assistant/contentwindow.h
index e5512f5..6395932 100644
--- a/tools/assistant/tools/assistant/contentwindow.h
+++ b/tools/assistant/tools/assistant/contentwindow.h
@@ -57,7 +57,7 @@ class ContentWindow : public QWidget
     Q_OBJECT
 
 public:
-    ContentWindow(QHelpEngine *helpEngine);
+    ContentWindow();
     ~ContentWindow();
 
     bool syncToContent(const QUrl &url);
@@ -78,8 +78,7 @@ private:
     bool eventFilter(QObject *o, QEvent *e);
     bool isPdfFile(QHelpContentItem *item) const;
 
-    QHelpEngine *m_helpEngine;
-    QHelpContentWidget *m_contentWidget;
+    QHelpContentWidget * const m_contentWidget;
     int m_expandDepth;
 };
 
diff --git a/tools/assistant/tools/assistant/helpenginewrapper.cpp b/tools/assistant/tools/assistant/helpenginewrapper.cpp
new file mode 100644
index 0000000..d399d1e
--- /dev/null
+++ b/tools/assistant/tools/assistant/helpenginewrapper.cpp
@@ -0,0 +1,591 @@
+/****************************************************************************
+**
+** Copyright (C) 2009 Nokia Corporation and/or its subsidiary(-ies).
+** All rights reserved.
+** Contact: Nokia Corporation (qt-info@nokia.com)
+**
+** This file is part of the Qt Assistant 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 "helpenginewrapper.h"
+#include "../shared/collectionconfiguration.h"
+
+#include <QtCore/QFileInfo>
+#include <QtCore/QFileSystemWatcher>
+#include <QtHelp/QHelpContentModel>
+#include <QtHelp/QHelpEngine>
+#include <QtHelp/QHelpIndexModel>
+#include <QtHelp/QHelpSearchEngine>
+
+QT_BEGIN_NAMESPACE
+
+namespace {
+    const QString AppFontKey(QLatin1String("appFont"));
+    const QString AppWritingSystemKey(QLatin1String("appWritingSystem"));
+    const QString BookmarksKey(QLatin1String("Bookmarks"));
+    const QString BrowserFontKey(QLatin1String("browserFont"));
+    const QString BrowserWritingSystemKey(QLatin1String("browserWritingSystem"));
+    const QString HomePageKey(QLatin1String("homepage"));
+    const QString MainWindowKey(QLatin1String("MainWindow"));
+    const QString MainWindowGeometryKey(QLatin1String("MainWindowGeometry"));
+    const QString SearchWasAttachedKey(QLatin1String("SearchWasAttached"));
+    const QString StartOptionKey(QLatin1String("StartOption"));
+    const QString UnfilteredInsertedKey(QLatin1String("UnfilteredFilterInserted"));
+    const QString UseAppFontKey(QLatin1String("useAppFont"));
+    const QString UseBrowserFontKey(QLatin1String("useBrowserFont"));
+    const QString VersionKey(QString(QLatin1String("qtVersion%1$$$%2")).
+                             arg(QLatin1String(QT_VERSION_STR)));
+} // anonymous namespace
+
+HelpEngineWrapper *HelpEngineWrapper::helpEngineWrapper = 0;
+
+HelpEngineWrapper &HelpEngineWrapper::instance(const QString &collectionFile)
+{
+    /*
+     * Note that this Singleton cannot be static, because it has to be
+     * deleted before the QApplication.
+     */
+    if (helpEngineWrapper == 0)
+        helpEngineWrapper = new HelpEngineWrapper(collectionFile);
+    return *helpEngineWrapper;
+}
+
+void HelpEngineWrapper::removeInstance()
+{
+    delete helpEngineWrapper;
+    helpEngineWrapper = 0;
+}
+
+HelpEngineWrapper::HelpEngineWrapper(const QString &collectionFile)
+    : m_helpEngine(new QHelpEngine(collectionFile, this)),
+      m_qchWatcher(new QFileSystemWatcher(this))
+{
+    connect(m_helpEngine, SIGNAL(currentFilterChanged(QString)),
+            this, SIGNAL(currentFilterChanged(QString)));
+    connect(m_helpEngine, SIGNAL(setupFinished()),
+            this, SIGNAL(setupFinished()));
+}
+
+void HelpEngineWrapper::initFileSystemWatchers()
+{
+    foreach(const QString &ns, m_helpEngine->registeredDocumentations()) {
+        const QString &docFile = m_helpEngine->documentationFileName(ns);
+        m_qchWatcher->addPath(docFile);
+        connect(m_qchWatcher, SIGNAL(fileChanged(QString)),
+                this, SLOT(qchFileChanged(QString)));
+    }
+    assertDocFilesWatched();
+}
+
+QHelpSearchEngine *HelpEngineWrapper::searchEngine() const
+{
+    return m_helpEngine->searchEngine();
+}
+
+QHelpContentModel *HelpEngineWrapper::contentModel() const
+{
+    return m_helpEngine->contentModel();
+}
+
+QHelpIndexModel *HelpEngineWrapper::indexModel() const
+{
+    return m_helpEngine->indexModel();
+}
+
+QHelpContentWidget *HelpEngineWrapper::contentWidget()
+{
+    return m_helpEngine->contentWidget();
+}
+
+QHelpIndexWidget *HelpEngineWrapper::indexWidget()
+{
+    return m_helpEngine->indexWidget();
+}
+
+const QStringList HelpEngineWrapper::registeredDocumentations() const
+{
+    return m_helpEngine->registeredDocumentations();
+}
+
+const QString HelpEngineWrapper::collectionFile() const
+{
+    return m_helpEngine->collectionFile();
+}
+
+bool HelpEngineWrapper::registerDocumentation(const QString &docFile)
+{
+    if (!m_helpEngine->registerDocumentation(docFile))
+        return false;
+    m_qchWatcher->addPath(docFile);
+    assertDocFilesWatched();
+    return true;
+}
+
+bool HelpEngineWrapper::unregisterDocumentation(const QString &namespaceName)
+{
+    const QString &internalFile =
+        m_helpEngine->documentationFileName(namespaceName);
+    if (!m_helpEngine->unregisterDocumentation(namespaceName))
+        return false;
+    m_qchWatcher->removePath(internalFile);
+    assertDocFilesWatched();
+    return true;
+}
+
+bool HelpEngineWrapper::setupData()
+{
+    return m_helpEngine->setupData();
+}
+
+bool HelpEngineWrapper::addCustomFilter(const QString &filterName,
+                                        const QStringList &attributes)
+{
+    return m_helpEngine->addCustomFilter(filterName, attributes);
+}
+
+bool HelpEngineWrapper::removeCustomFilter(const QString &filterName)
+{
+    return m_helpEngine->removeCustomFilter(filterName);
+}
+
+void HelpEngineWrapper::setCurrentFilter(const QString &currentFilter)
+{
+    m_helpEngine->setCurrentFilter(currentFilter);
+}
+
+const QString HelpEngineWrapper::currentFilter() const
+{
+    return m_helpEngine->currentFilter();
+}
+
+const QStringList HelpEngineWrapper::customFilters() const
+{
+    return m_helpEngine->customFilters();
+}
+
+QUrl HelpEngineWrapper::findFile(const QUrl &url) const
+{
+    return m_helpEngine->findFile(url);
+}
+
+QByteArray HelpEngineWrapper::fileData(const QUrl &url) const
+{
+    return m_helpEngine->fileData(url);
+}
+
+QMap<QString, QUrl> HelpEngineWrapper::linksForIdentifier(const QString &id) const
+{
+    return m_helpEngine->linksForIdentifier(id);
+}
+
+const QStringList HelpEngineWrapper::filterAttributes() const
+{
+    return m_helpEngine->filterAttributes();
+}
+
+const QStringList HelpEngineWrapper::filterAttributes(const QString &filterName) const
+{
+    return m_helpEngine->filterAttributes(filterName);
+}
+
+QString HelpEngineWrapper::error() const
+{
+    return m_helpEngine->error();
+}
+
+bool HelpEngineWrapper::unfilteredInserted() const
+{
+    return m_helpEngine->customValue(UnfilteredInsertedKey).toInt() == 1;
+}
+
+void HelpEngineWrapper::setUnfilteredInserted()
+{
+    m_helpEngine->setCustomValue(UnfilteredInsertedKey, 1);
+}
+
+const QStringList HelpEngineWrapper::qtDocInfo(const QString &component) const
+{
+    return m_helpEngine->customValue(VersionKey.arg(component)).toString().
+        split(CollectionConfiguration::ListSeparator);
+}
+
+void HelpEngineWrapper::setQtDocInfo(const QString &component,
+                                     const QStringList &doc)
+{
+    m_helpEngine->setCustomValue(VersionKey.arg(component),
+                              doc.join(CollectionConfiguration::ListSeparator));
+}
+
+const QStringList HelpEngineWrapper::lastShownPages() const
+{
+    return CollectionConfiguration::lastShownPages(*m_helpEngine);
+}
+
+void HelpEngineWrapper::setLastShownPages(const QStringList &lastShownPages)
+{
+    CollectionConfiguration::setLastShownPages(*m_helpEngine, lastShownPages);
+}
+
+const QStringList HelpEngineWrapper::lastZoomFactors() const
+{
+    return CollectionConfiguration::lastZoomFactors(*m_helpEngine);
+}
+
+void HelpEngineWrapper::setLastZoomFactors(const QStringList &lastZoomFactors)
+{
+    CollectionConfiguration::setLastZoomFactors(*m_helpEngine, lastZoomFactors);
+}
+
+const QString HelpEngineWrapper::cacheDir() const
+{
+    return CollectionConfiguration::cacheDir(*m_helpEngine);
+}
+
+bool HelpEngineWrapper::cacheDirIsRelativeToCollection() const
+{
+    return CollectionConfiguration::cacheDirIsRelativeToCollection(*m_helpEngine);
+}
+
+void HelpEngineWrapper::setCacheDir(const QString &cacheDir,
+                                    bool relativeToCollection)
+{
+    CollectionConfiguration::setCacheDir(*m_helpEngine, cacheDir,
+                                         relativeToCollection);
+}
+
+bool HelpEngineWrapper::filterFunctionalityEnabled() const
+{
+    return CollectionConfiguration::filterFunctionalityEnabled(*m_helpEngine);
+}
+
+void HelpEngineWrapper::setFilterFunctionalityEnabled(bool enabled)
+{
+    CollectionConfiguration::setFilterFunctionalityEnabled(*m_helpEngine,
+                                                           enabled);
+}
+
+bool HelpEngineWrapper::filterToolbarVisible() const
+{
+    return CollectionConfiguration::filterToolbarVisible(*m_helpEngine);
+}
+
+void HelpEngineWrapper::setFilterToolbarVisible(bool visible)
+{
+    CollectionConfiguration::setFilterToolbarVisible(*m_helpEngine, visible);
+}
+
+bool HelpEngineWrapper::addressBarEnabled() const
+{
+    return CollectionConfiguration::addressBarEnabled(*m_helpEngine);
+}
+
+void HelpEngineWrapper::setAddressBarEnabled(bool enabled)
+{
+    CollectionConfiguration::setAddressBarEnabled(*m_helpEngine, enabled);
+}
+
+bool HelpEngineWrapper::addressBarVisible() const
+{
+    return CollectionConfiguration::addressBarVisible(*m_helpEngine);
+}
+
+void HelpEngineWrapper::setAddressBarVisible(bool visible)
+{
+    CollectionConfiguration::setAddressBarVisible(*m_helpEngine, visible);
+}
+
+bool HelpEngineWrapper::documentationManagerEnabled() const
+{
+    return CollectionConfiguration::documentationManagerEnabled(*m_helpEngine);
+}
+
+void HelpEngineWrapper::setDocumentationManagerEnabled(bool enabled)
+{
+    CollectionConfiguration::setDocumentationManagerEnabled(*m_helpEngine,
+                                                            enabled);
+}
+
+const QByteArray HelpEngineWrapper::aboutMenuTexts() const
+{
+    return CollectionConfiguration::aboutMenuTexts(*m_helpEngine);
+}
+
+void HelpEngineWrapper::setAboutMenuTexts(const QByteArray &texts)
+{
+    CollectionConfiguration::setAboutMenuTexts(*m_helpEngine, texts);
+}
+
+const QByteArray HelpEngineWrapper::aboutIcon() const
+{
+    return CollectionConfiguration::aboutIcon(*m_helpEngine);
+}
+
+void HelpEngineWrapper::setAboutIcon(const QByteArray &icon)
+{
+    CollectionConfiguration::setAboutIcon(*m_helpEngine, icon);
+}
+
+const QByteArray HelpEngineWrapper::aboutImages() const
+{
+    return CollectionConfiguration::aboutImages(*m_helpEngine);
+}
+
+void HelpEngineWrapper::setAboutImages(const QByteArray &images)
+{
+    CollectionConfiguration::setAboutImages(*m_helpEngine, images);
+}
+
+const QByteArray HelpEngineWrapper::aboutTexts() const
+{
+    return CollectionConfiguration::aboutTexts(*m_helpEngine);
+}
+
+void HelpEngineWrapper::setAboutTexts(const QByteArray &texts)
+{
+    CollectionConfiguration::setAboutTexts(*m_helpEngine, texts);
+}
+
+const QString HelpEngineWrapper::windowTitle() const
+{
+    return CollectionConfiguration::windowTitle(*m_helpEngine);
+}
+
+void HelpEngineWrapper::setWindowTitle(const QString &windowTitle)
+{
+    CollectionConfiguration::setWindowTitle(*m_helpEngine, windowTitle);
+}
+
+const QByteArray HelpEngineWrapper::applicationIcon() const
+{
+    return CollectionConfiguration::applicationIcon(*m_helpEngine);
+}
+
+void HelpEngineWrapper::setApplicationIcon(const QByteArray &icon)
+{
+    CollectionConfiguration::setApplicationIcon(*m_helpEngine, icon);
+}
+
+const QByteArray HelpEngineWrapper::mainWindow() const
+{
+    return m_helpEngine->customValue(MainWindowKey).toByteArray();
+}
+
+void HelpEngineWrapper::setMainWindow(const QByteArray &mainWindow)
+{
+    m_helpEngine->setCustomValue(MainWindowKey, mainWindow);
+}
+
+const QByteArray HelpEngineWrapper::mainWindowGeometry() const
+{
+    return m_helpEngine->customValue(MainWindowGeometryKey).toByteArray();
+}
+
+void HelpEngineWrapper::setMainWindowGeometry(const QByteArray &geometry)
+{
+    m_helpEngine->setCustomValue(MainWindowGeometryKey, geometry);
+}
+
+const QByteArray HelpEngineWrapper::bookmarks() const
+{
+    return m_helpEngine->customValue(BookmarksKey).toByteArray();
+}
+
+void HelpEngineWrapper::setBookmarks(const QByteArray &bookmarks)
+{
+    m_helpEngine->setCustomValue(BookmarksKey, bookmarks);
+}
+
+int HelpEngineWrapper::lastTabPage() const
+{
+    return CollectionConfiguration::lastTabPage(*m_helpEngine);
+}
+
+void HelpEngineWrapper::setLastTabPage(int lastPage)
+{
+    CollectionConfiguration::setLastTabPage(*m_helpEngine, lastPage);
+}
+
+bool HelpEngineWrapper::searchWasAttached() const
+{
+    return m_helpEngine->customValue(SearchWasAttachedKey).toBool();
+}
+
+void HelpEngineWrapper::setSearchWasAttached(bool attached)
+{
+    m_helpEngine->setCustomValue(SearchWasAttachedKey, attached);
+}
+
+int HelpEngineWrapper::startOption() const
+{
+    return m_helpEngine->customValue(StartOptionKey, ShowLastPages).toInt();
+}
+
+void HelpEngineWrapper::setStartOption(int option)
+{
+    m_helpEngine->setCustomValue(StartOptionKey, option);
+}
+
+const QString HelpEngineWrapper::homePage() const
+{
+    const QString &homePage = m_helpEngine->customValue(HomePageKey).toString();
+    if (!homePage.isEmpty())
+        return homePage;
+    return defaultHomePage();
+}
+
+void HelpEngineWrapper::setHomePage(const QString &page)
+{
+    m_helpEngine->setCustomValue(HomePageKey, page);
+
+}
+
+const QString HelpEngineWrapper::defaultHomePage() const
+{
+    return CollectionConfiguration::defaultHomePage(*m_helpEngine);
+}
+
+void HelpEngineWrapper::setDefaultHomePage(const QString &page)
+{
+    CollectionConfiguration::setDefaultHomePage(*m_helpEngine, page);
+}
+
+bool HelpEngineWrapper::hasFontSettings() const
+{
+    return m_helpEngine->customValue(UseAppFontKey).isValid();
+}
+
+bool HelpEngineWrapper::usesAppFont() const
+{
+    return m_helpEngine->customValue(UseAppFontKey).toBool();
+}
+
+void HelpEngineWrapper::setUseAppFont(bool useAppFont)
+{
+    m_helpEngine->setCustomValue(UseAppFontKey, useAppFont);
+}
+
+bool HelpEngineWrapper::usesBrowserFont() const
+{
+    return m_helpEngine->customValue(UseBrowserFontKey, false).toBool();
+}
+
+void HelpEngineWrapper::setUseBrowserFont(bool useBrowserFont)
+{
+    m_helpEngine->setCustomValue(UseBrowserFontKey, useBrowserFont);
+}
+
+const QFont HelpEngineWrapper::appFont() const
+{
+    return qVariantValue<QFont>(m_helpEngine->customValue(AppFontKey));
+}
+
+void HelpEngineWrapper::setAppFont(const QFont &font)
+{
+    m_helpEngine->setCustomValue(AppFontKey, font);
+}
+
+QFontDatabase::WritingSystem HelpEngineWrapper::appWritingSystem() const
+{
+    return static_cast<QFontDatabase::WritingSystem>(
+        m_helpEngine->customValue(AppWritingSystemKey).toInt());
+}
+
+void HelpEngineWrapper::setAppWritingSystem(QFontDatabase::WritingSystem system)
+{
+    m_helpEngine->setCustomValue(AppWritingSystemKey, system);
+}
+
+const QFont HelpEngineWrapper::browserFont() const
+{
+    return qVariantValue<QFont>(m_helpEngine->customValue(BrowserFontKey));
+}
+
+void HelpEngineWrapper::setBrowserFont(const QFont &font)
+{
+    m_helpEngine->setCustomValue(BrowserFontKey, font);
+}
+
+QFontDatabase::WritingSystem HelpEngineWrapper::browserWritingSystem() const
+{
+    return static_cast<QFontDatabase::WritingSystem>(
+        m_helpEngine->customValue(BrowserWritingSystemKey).toInt());
+}
+
+void HelpEngineWrapper::setBrowserWritingSystem(QFontDatabase::WritingSystem system)
+{
+    m_helpEngine->setCustomValue(BrowserWritingSystemKey, system);
+}
+
+
+void HelpEngineWrapper::assertDocFilesWatched()
+{
+    Q_ASSERT(m_qchWatcher->files().count()
+             == m_helpEngine->registeredDocumentations().count());
+}
+
+void HelpEngineWrapper::qchFileChanged(const QString &fileName)
+{
+    /*
+     * We don't use QHelpEngineCore::namespaceName(fileName), because the file
+     * may not exist anymore or contain a different namespace.
+     */
+    QString ns;
+    foreach (const QString &curNs, m_helpEngine->registeredDocumentations()) {
+        if (m_helpEngine->documentationFileName(curNs) == fileName) {
+            ns = curNs;
+            break;
+        }
+    }
+
+    /*
+     * We can't do an assertion here, because QFileSystemWatcher may send the
+     * signal more than  once.
+     */
+    if (ns.isEmpty())
+        return;
+
+    if (m_helpEngine->unregisterDocumentation(ns)) {
+        if (!QFileInfo(fileName).exists()
+            || !m_helpEngine->registerDocumentation(fileName)) {
+            m_qchWatcher->removePath(fileName);
+            emit documentationRemoved(ns);
+        } else {
+            emit documentationUpdated(ns);
+        }
+        m_helpEngine->setupData();
+    }
+}
+
+QT_END_NAMESPACE
diff --git a/tools/assistant/tools/assistant/helpenginewrapper.h b/tools/assistant/tools/assistant/helpenginewrapper.h
new file mode 100644
index 0000000..1fc9eb6
--- /dev/null
+++ b/tools/assistant/tools/assistant/helpenginewrapper.h
@@ -0,0 +1,212 @@
+/****************************************************************************
+**
+** Copyright (C) 2009 Nokia Corporation and/or its subsidiary(-ies).
+** All rights reserved.
+** Contact: Nokia Corporation (qt-info@nokia.com)
+**
+** This file is part of the Qt Assistant 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 HELPENGINEWRAPPER_H
+#define HELPENGINEWRAPPER_H
+
+#include <QtCore/QMap>
+#include <QtCore/QObject>
+#include <QtCore/QString>
+#include <QtCore/QStringList>
+#include <QtCore/QUrl>
+#include <QtGui/QFont>
+#include <QtGui/QFontDatabase>
+
+QT_BEGIN_NAMESPACE
+
+class QFileSystemWatcher;
+class QHelpContentModel;
+class QHelpContentWidget;
+class QHelpEngine;
+class QHelpEngineCore;
+class QHelpIndexModel;
+class QHelpIndexWidget;
+class QHelpSearchEngine;
+
+enum {
+    ShowHomePage = 0,
+    ShowBlankPage = 1,
+    ShowLastPages = 2
+};
+
+class HelpEngineWrapper : public QObject
+{
+    Q_OBJECT
+    Q_DISABLE_COPY(HelpEngineWrapper)
+public:
+    static HelpEngineWrapper &instance(const QString &collectionFile = QString());
+    static void removeInstance();
+
+    void initFileSystemWatchers();
+
+    // Forwarded help engine member functions, possibly enriched.
+    QHelpSearchEngine *searchEngine() const;
+    QHelpContentModel *contentModel() const;
+    QHelpIndexModel *indexModel() const;
+    QHelpContentWidget *contentWidget();
+    QHelpIndexWidget *indexWidget();
+    bool setupData();
+    const QStringList registeredDocumentations() const;
+    const QString collectionFile() const;
+    bool registerDocumentation(const QString &docFile);
+    bool unregisterDocumentation(const QString &namespaceName);
+    bool addCustomFilter(const QString &filterName,
+                         const QStringList &attributes);
+    bool removeCustomFilter(const QString &filterName);
+    void setCurrentFilter(const QString &filterName);
+    const QString currentFilter() const;
+    const QStringList customFilters() const;
+    QUrl findFile(const QUrl &url) const;
+    QByteArray fileData(const QUrl &url) const;
+    QMap<QString, QUrl>	linksForIdentifier(const QString &id) const;
+    const QStringList filterAttributes() const;
+    const QStringList filterAttributes(const QString &filterName) const;
+    QString	error() const;   
+
+    // Access to a collection's custom values.
+    bool unfilteredInserted() const;
+    void setUnfilteredInserted();
+
+    const QStringList qtDocInfo(const QString &component) const;
+    void setQtDocInfo(const QString &component, const QStringList &doc);
+
+    const QString homePage() const;
+    void setHomePage(const QString &page);
+    const QString defaultHomePage() const;
+    void setDefaultHomePage(const QString &page);
+
+    int lastTabPage() const;
+    void setLastTabPage(int lastPage);
+
+    // TODO: Don't allow last pages and zoom factors to be set in isolation
+    //       Perhaps also fill up missing elements automatically or assert.
+    const QStringList lastShownPages() const;
+    void setLastShownPages(const QStringList &lastShownPages);
+    const QStringList lastZoomFactors() const;
+    void setLastZoomFactors(const QStringList &lastZoomFactors);
+
+    const QString cacheDir() const;
+    bool cacheDirIsRelativeToCollection() const;
+    void setCacheDir(const QString &cacheDir, bool relativeToCollection);
+
+    bool filterFunctionalityEnabled() const;
+    void setFilterFunctionalityEnabled(bool enabled);
+
+    bool filterToolbarVisible() const;
+    void setFilterToolbarVisible(bool visible);
+
+    bool addressBarEnabled() const;
+    void setAddressBarEnabled(bool enabled);
+
+    bool addressBarVisible() const;
+    void setAddressBarVisible(bool visible);
+
+    bool documentationManagerEnabled() const;
+    void setDocumentationManagerEnabled(bool enabled);
+
+    const QByteArray aboutMenuTexts() const;
+    void setAboutMenuTexts(const QByteArray &texts);
+    const QByteArray aboutTexts() const;
+    void setAboutTexts(const QByteArray &texts);
+    const QByteArray aboutIcon() const;
+    void setAboutIcon(const QByteArray &icon);
+    const QByteArray aboutImages() const;
+    void setAboutImages(const QByteArray &images);
+
+    const QString windowTitle() const;
+    void setWindowTitle(const QString &windowTitle);
+
+    const QByteArray applicationIcon() const;
+    void setApplicationIcon(const QByteArray &icon);
+
+    const QByteArray mainWindow() const;
+    void setMainWindow(const QByteArray &mainWindow);
+    const QByteArray mainWindowGeometry() const;
+    void setMainWindowGeometry(const QByteArray &geometry);
+
+    const QByteArray bookmarks() const;
+    void setBookmarks(const QByteArray &bookmarks);
+
+    int startOption() const;
+    void setStartOption(int option);
+
+    bool searchWasAttached() const;
+    void setSearchWasAttached(bool attached);
+
+    bool hasFontSettings() const;
+    bool usesAppFont() const;
+    void setUseAppFont(bool useAppFont);
+    bool usesBrowserFont() const;
+    void setUseBrowserFont(bool useBrowserFont);
+    const QFont appFont() const;
+    void setAppFont(const QFont &font);
+    QFontDatabase::WritingSystem appWritingSystem() const;
+    void setAppWritingSystem(QFontDatabase::WritingSystem system);
+    const QFont browserFont() const;
+    void setBrowserFont(const QFont &font);
+    QFontDatabase::WritingSystem browserWritingSystem() const;
+    void setBrowserWritingSystem(QFontDatabase::WritingSystem system);
+
+signals:
+
+    // For asynchronous doc updates triggered by external actions.
+    void documentationRemoved(const QString &namespaceName);
+    void documentationUpdated(const QString &namespaceName);
+
+    // Forwarded from QHelpEngineCore.
+    void currentFilterChanged(const QString &currentFilter);
+    void setupFinished();
+
+private slots:
+    void qchFileChanged(const QString &fileName);
+
+private:
+    HelpEngineWrapper(const QString &collectionFile);
+    void assertDocFilesWatched();
+
+    static HelpEngineWrapper *helpEngineWrapper;
+    QHelpEngine * const m_helpEngine;
+    QFileSystemWatcher * const m_qchWatcher;
+};
+
+QT_END_NAMESPACE
+
+#endif // HELPENGINEWRAPPER_H
diff --git a/tools/assistant/tools/assistant/helpviewer.cpp b/tools/assistant/tools/assistant/helpviewer.cpp
index 2756753..5f2c02b 100644
--- a/tools/assistant/tools/assistant/helpviewer.cpp
+++ b/tools/assistant/tools/assistant/helpviewer.cpp
@@ -41,7 +41,7 @@
 
 #include "helpviewer.h"
 #include "centralwidget.h"
-#include "../shared/collectionconfiguration.h"
+#include "helpenginewrapper.h"
 
 #include <QtCore/QDir>
 #include <QtCore/QEvent>
@@ -56,8 +56,6 @@
 #include <QtGui/QMessageBox>
 #include <QtGui/QDesktopServices>
 
-#include <QtHelp/QHelpEngine>
-
 #include <QNetworkAccessManager>
 #include <QNetworkReply>
 #include <QNetworkRequest>
@@ -124,19 +122,15 @@ qint64 HelpNetworkReply::readData(char *buffer, qint64 maxlen)
 class HelpNetworkAccessManager : public QNetworkAccessManager
 {
 public:
-    HelpNetworkAccessManager(QHelpEngine *engine, QObject *parent);
+    HelpNetworkAccessManager(QObject *parent);
 
 protected:
     virtual QNetworkReply *createRequest(Operation op,
         const QNetworkRequest &request, QIODevice *outgoingData = 0);
-
-private:
-    QHelpEngine *helpEngine;
 };
 
-HelpNetworkAccessManager::HelpNetworkAccessManager(QHelpEngine *engine,
-        QObject *parent)
-    : QNetworkAccessManager(parent), helpEngine(engine)
+HelpNetworkAccessManager::HelpNetworkAccessManager(QObject *parent)
+    : QNetworkAccessManager(parent)
 {
 }
 
@@ -158,8 +152,9 @@ QNetworkReply *HelpNetworkAccessManager::createRequest(Operation /*op*/,
         mimeType = QLatin1String("text/html");
     }
 
-    const QByteArray &data = helpEngine->findFile(url).isValid()
-        ? helpEngine->fileData(url)
+    HelpEngineWrapper &helpEngine = HelpEngineWrapper::instance();
+    const QByteArray &data = helpEngine.findFile(url).isValid()
+        ? helpEngine.fileData(url)
         : PageNotFoundMessage.arg(url.toString()).toUtf8();
     return new HelpNetworkReply(request, data, mimeType);
 }
@@ -167,7 +162,7 @@ QNetworkReply *HelpNetworkAccessManager::createRequest(Operation /*op*/,
 class HelpPage : public QWebPage
 {
 public:
-    HelpPage(CentralWidget *central, QHelpEngine *engine, QObject *parent);
+    HelpPage(CentralWidget *central, QObject *parent);
 
 protected:
     virtual QWebPage *createWindow(QWebPage::WebWindowType);
@@ -178,7 +173,6 @@ protected:
 
 private:
     CentralWidget *centralWidget;
-    QHelpEngine *helpEngine;
     bool closeNewTabIfNeeded;
 
     friend class HelpViewer;
@@ -186,10 +180,9 @@ private:
     Qt::KeyboardModifiers m_keyboardModifiers;
 };
 
-HelpPage::HelpPage(CentralWidget *central, QHelpEngine *engine, QObject *parent)
+HelpPage::HelpPage(CentralWidget *central, QObject *parent)
     : QWebPage(parent)
     , centralWidget(central)
-    , helpEngine(engine)
     , closeNewTabIfNeeded(false)
     , m_pressedButtons(Qt::NoButton)
     , m_keyboardModifiers(Qt::NoModifier)
@@ -248,7 +241,7 @@ bool HelpPage::acceptNavigationRequest(QWebFrame *,
 
             QFile tmpFile(QDir::cleanPath(fileName));
             if (tmpFile.open(QIODevice::ReadWrite)) {
-                tmpFile.write(helpEngine->fileData(url));
+                tmpFile.write(HelpEngineWrapper::instance().fileData(url));
                 tmpFile.close();
             }
             QDesktopServices::openUrl(QUrl(tmpFile.fileName()));
@@ -275,17 +268,17 @@ bool HelpPage::acceptNavigationRequest(QWebFrame *,
     return false;
 }
 
-HelpViewer::HelpViewer(QHelpEngine *engine, CentralWidget *parent)
+HelpViewer::HelpViewer(CentralWidget *parent)
     : QWebView(parent)
-    , helpEngine(engine)
     , parentWidget(parent)
     , loadFinished(false)
+    , helpEngine(HelpEngineWrapper::instance())
 {
     setAcceptDrops(false);
 
-    setPage(new HelpPage(parent, helpEngine, this));
+    setPage(new HelpPage(parent, this));
 
-    page()->setNetworkAccessManager(new HelpNetworkAccessManager(engine, this));
+    page()->setNetworkAccessManager(new HelpNetworkAccessManager(this));
 
     QAction* action = pageAction(QWebPage::OpenLinkInNewWindow);
     action->setText(tr("Open Link in New Tab"));
@@ -392,13 +385,13 @@ void HelpViewer::setLoadFinished(bool ok)
 
 #else  // !defined(QT_NO_WEBKIT)
 
-HelpViewer::HelpViewer(QHelpEngine *engine, CentralWidget *parent)
+HelpViewer::HelpViewer(CentralWidget *parent)
     : QTextBrowser(parent)
     , zoomCount(0)
     , controlPressed(false)
     , lastAnchor(QString())
-    , helpEngine(engine)
     , parentWidget(parent)
+    , helpEngine(HelpEngineWrapper::instance())
 {
    document()->setDocumentMargin(8);
 }
@@ -410,7 +403,7 @@ void HelpViewer::setSource(const QUrl &url)
         if (launchedWithExternalApp(url))
             return;
 
-        QUrl u = helpEngine->findFile(url);
+        QUrl u = helpEngine.findFile(url);
         if (u.isValid()) {
             QTextBrowser::setSource(u);
             return;
@@ -472,7 +465,7 @@ bool HelpViewer::launchedWithExternalApp(const QUrl &url)
 
             QFile tmpFile(QDir::cleanPath(fileName));
             if (tmpFile.open(QIODevice::ReadWrite)) {
-                tmpFile.write(helpEngine->fileData(url));
+                tmpFile.write(helpEngine.fileData(url));
                 tmpFile.close();
             }
             launched = QDesktopServices::openUrl(QUrl(tmpFile.fileName()));
@@ -493,7 +486,7 @@ QVariant HelpViewer::loadResource(int type, const QUrl &name)
 {
     QByteArray ba;
     if (type < 4) {
-        ba = helpEngine->fileData(name);
+        ba = helpEngine.fileData(name);
         if (name.toString().endsWith(QLatin1String(".svg"), Qt::CaseInsensitive)) {
             QImage image;
             image.loadFromData(ba, "svg");
@@ -606,10 +599,7 @@ void HelpViewer::wheelEvent(QWheelEvent *e)
 
 void HelpViewer::home()
 {
-    QString homePage = CollectionConfiguration::homePage(*helpEngine);
-    if (homePage.isEmpty())
-        homePage = CollectionConfiguration::defaultHomePage(*helpEngine);
-    setSource(homePage);
+    setSource(helpEngine.homePage());
 }
 
 QT_END_NAMESPACE
diff --git a/tools/assistant/tools/assistant/helpviewer.h b/tools/assistant/tools/assistant/helpviewer.h
index 350209b..64742b5 100644
--- a/tools/assistant/tools/assistant/helpviewer.h
+++ b/tools/assistant/tools/assistant/helpviewer.h
@@ -53,8 +53,8 @@
 
 QT_BEGIN_NAMESPACE
 
-class QHelpEngine;
 class CentralWidget;
+class HelpEngineWrapper;
 
 class QPoint;
 class QString;
@@ -69,7 +69,7 @@ class HelpViewer : public QWebView
     Q_OBJECT
 
 public:
-    HelpViewer(QHelpEngine *helpEngine, CentralWidget *parent);
+    HelpViewer(CentralWidget *parent);
     void setSource(const QUrl &url);
 
     inline QUrl source() const
@@ -118,9 +118,9 @@ private Q_SLOTS:
     void setLoadFinished(bool ok);
 
 private:
-    QHelpEngine *helpEngine;
     CentralWidget* parentWidget;
     bool loadFinished;
+    HelpEngineWrapper &helpEngine;
 };
 
 #else
@@ -130,7 +130,7 @@ class HelpViewer : public QTextBrowser
     Q_OBJECT
 
 public:
-    HelpViewer(QHelpEngine *helpEngine, CentralWidget *parent);
+    HelpViewer(CentralWidget *parent);
     void setSource(const QUrl &url);
 
     void resetZoom();
@@ -165,8 +165,8 @@ private:
     int zoomCount;
     bool controlPressed;
     QString lastAnchor;
-    QHelpEngine *helpEngine;
     CentralWidget* parentWidget;
+    HelpEngineWrapper &helpEngine;
 };
 
 #endif
diff --git a/tools/assistant/tools/assistant/indexwindow.cpp b/tools/assistant/tools/assistant/indexwindow.cpp
index 6d35649..757a641 100644
--- a/tools/assistant/tools/assistant/indexwindow.cpp
+++ b/tools/assistant/tools/assistant/indexwindow.cpp
@@ -41,6 +41,7 @@
 
 #include "indexwindow.h"
 #include "centralwidget.h"
+#include "helpenginewrapper.h"
 #include "topicchooser.h"
 
 #include <QtGui/QLayout>
@@ -51,22 +52,19 @@
 #include <QtGui/QContextMenuEvent>
 #include <QtGui/QListWidgetItem>
 
-#include <QtHelp/QHelpEngine>
 #include <QtHelp/QHelpIndexWidget>
 
 QT_BEGIN_NAMESPACE
 
-IndexWindow::IndexWindow(QHelpEngine *helpEngine, QWidget *parent)
+IndexWindow::IndexWindow(QWidget *parent)
     : QWidget(parent)
-    , m_searchLineEdit(0)
-    , m_indexWidget(0)
-    , m_helpEngine(helpEngine)
+    , m_searchLineEdit(new QLineEdit)
+    , m_indexWidget(HelpEngineWrapper::instance().indexWidget())
 {
     QVBoxLayout *layout = new QVBoxLayout(this);
     QLabel *l = new QLabel(tr("&Look for:"));
     layout->addWidget(l);
 
-    m_searchLineEdit = new QLineEdit();
     l->setBuddy(m_searchLineEdit);
     connect(m_searchLineEdit, SIGNAL(textChanged(QString)), this,
         SLOT(filterIndices(QString)));
@@ -74,11 +72,11 @@ IndexWindow::IndexWindow(QHelpEngine *helpEngine, QWidget *parent)
     layout->setMargin(4);
     layout->addWidget(m_searchLineEdit);
 
-    m_indexWidget = m_helpEngine->indexWidget();
+    HelpEngineWrapper &helpEngine = HelpEngineWrapper::instance();
     m_indexWidget->installEventFilter(this);
-    connect(m_helpEngine->indexModel(), SIGNAL(indexCreationStarted()), this,
+    connect(helpEngine.indexModel(), SIGNAL(indexCreationStarted()), this,
         SLOT(disableSearchLineEdit()));
-    connect(m_helpEngine->indexModel(), SIGNAL(indexCreated()), this,
+    connect(helpEngine.indexModel(), SIGNAL(indexCreated()), this,
         SLOT(enableSearchLineEdit()));
     connect(m_indexWidget, SIGNAL(linkActivated(QUrl,QString)), this,
         SIGNAL(linkActivated(QUrl)));
diff --git a/tools/assistant/tools/assistant/indexwindow.h b/tools/assistant/tools/assistant/indexwindow.h
index 5973e43..6fbb250 100644
--- a/tools/assistant/tools/assistant/indexwindow.h
+++ b/tools/assistant/tools/assistant/indexwindow.h
@@ -49,7 +49,6 @@
 QT_BEGIN_NAMESPACE
 
 class QHelpIndexWidget;
-class QHelpEngine;
 class QModelIndex;
 
 class IndexWindow : public QWidget
@@ -57,7 +56,7 @@ class IndexWindow : public QWidget
     Q_OBJECT
 
 public:
-    IndexWindow(QHelpEngine *helpEngine, QWidget *parent = 0);
+    IndexWindow(QWidget *parent = 0);
     ~IndexWindow();
 
     void setSearchLineEditText(const QString &text);
@@ -84,7 +83,6 @@ private:
 
     QLineEdit *m_searchLineEdit;
     QHelpIndexWidget *m_indexWidget;
-    QHelpEngine *m_helpEngine;
 };
 
 QT_END_NAMESPACE
diff --git a/tools/assistant/tools/assistant/main.cpp b/tools/assistant/tools/assistant/main.cpp
index ab7168c..4d93a41 100644
--- a/tools/assistant/tools/assistant/main.cpp
+++ b/tools/assistant/tools/assistant/main.cpp
@@ -57,9 +57,12 @@
 #include <QtSql/QSqlDatabase>
 
 #include "../shared/collectionconfiguration.h"
+#include "helpenginewrapper.h"
 #include "mainwindow.h"
 #include "cmdlineparser.h"
 
+// #define TRACING_REQUESTED
+
 QT_USE_NAMESPACE
 
 #if defined(USE_STATIC_SQLITE_PLUGIN)
@@ -317,8 +320,17 @@ int main(int argc, char *argv[])
     qtHelpTranslator.load(QLatin1String("qt_help_") + locale, resourceDir);
     a.installTranslator(&qtHelpTranslator);
 
-    MainWindow w(&cmd);
-    w.show();
+    /*
+     * We need to be careful here: The main window has to be deleted before
+     * the help engine wrapper, which has to be deleted before the
+     * QApplication.
+     */
+    int retval;
+    MainWindow *w = new MainWindow(&cmd);
+    w->show();
     a.connect(&a, SIGNAL(lastWindowClosed()), &a, SLOT(quit()));
-    return a.exec();
+    retval = a.exec();
+    delete w;
+    delete &HelpEngineWrapper::instance();
+    return retval;
 }
diff --git a/tools/assistant/tools/assistant/mainwindow.cpp b/tools/assistant/tools/assistant/mainwindow.cpp
index 2760f1e..226ad51 100644
--- a/tools/assistant/tools/assistant/mainwindow.cpp
+++ b/tools/assistant/tools/assistant/mainwindow.cpp
@@ -47,18 +47,22 @@
 #include "contentwindow.h"
 #include "preferencesdialog.h"
 #include "bookmarkmanager.h"
+#include "helpenginewrapper.h"
 #include "remotecontrol.h"
 #include "cmdlineparser.h"
 #include "aboutdialog.h"
 #include "searchwidget.h"
 #include "qtdocinstaller.h"
 #include "xbelsupport.h"
-#include "../shared/collectionconfiguration.h"
+
+// #define TRACING_REQUESTED
 
 #include <QtCore/QDir>
 #include <QtCore/QTimer>
+#include <QtCore/QDateTime>
 #include <QtCore/QDebug>
 #include <QtCore/QFileSystemWatcher>
+#include <QtCore/QPair>
 #include <QtCore/QResource>
 #include <QtCore/QByteArray>
 #include <QtCore/QTextStream>
@@ -81,7 +85,7 @@
 #include <QtGui/QToolButton>
 #include <QtGui/QFileDialog>
 
-#include <QtHelp/QHelpEngine>
+#include <QtHelp/QHelpEngineCore>
 #include <QtHelp/QHelpSearchEngine>
 #include <QtHelp/QHelpContentModel>
 #include <QtHelp/QHelpIndexModel>
@@ -95,29 +99,31 @@ MainWindow::MainWindow(CmdLineParser *cmdLine, QWidget *parent)
     , m_cmdLine(cmdLine)
     , m_progressWidget(0)
     , m_qtDocInstaller(0)
-    , m_qchWatcher(new QFileSystemWatcher(this))
     , m_connectedInitSignals(false)
 {
+
     setToolButtonStyle(Qt::ToolButtonFollowStyle);
 
+    QString collectionFile;
     if (usesDefaultCollection()) {
         MainWindow::collectionFileDirectory(true);
-        m_helpEngine = new QHelpEngine(MainWindow::defaultHelpCollectionFileName(),
-            this);
+        collectionFile = MainWindow::defaultHelpCollectionFileName();
     } else {
-        m_helpEngine = new QHelpEngine(cmdLine->collectionFile(), this);
+        collectionFile = cmdLine->collectionFile();
     }
+    HelpEngineWrapper &helpEngineWrapper =
+        HelpEngineWrapper::instance(collectionFile);
 
-    m_centralWidget = new CentralWidget(m_helpEngine, this);
+    m_centralWidget = new CentralWidget(this);
     setCentralWidget(m_centralWidget);
 
-    m_indexWindow = new IndexWindow(m_helpEngine);
+    m_indexWindow = new IndexWindow(this);
     QDockWidget *indexDock = new QDockWidget(tr("Index"), this);
     indexDock->setObjectName(QLatin1String("IndexWindow"));
     indexDock->setWidget(m_indexWindow);
     addDockWidget(Qt::LeftDockWidgetArea, indexDock);
 
-    m_contentWindow = new ContentWindow(m_helpEngine);
+    m_contentWindow = new ContentWindow;
     QDockWidget *contentDock = new QDockWidget(tr("Contents"), this);
     contentDock->setObjectName(QLatin1String("ContentWindow"));
     contentDock->setWidget(m_contentWindow);
@@ -128,7 +134,7 @@ MainWindow::MainWindow(CmdLineParser *cmdLine, QWidget *parent)
     bookmarkDock->setWidget(setupBookmarkWidget());
     addDockWidget(Qt::LeftDockWidgetArea, bookmarkDock);
 
-    QHelpSearchEngine *searchEngine = m_helpEngine->searchEngine();
+    QHelpSearchEngine *searchEngine = helpEngineWrapper.searchEngine();
     connect(searchEngine, SIGNAL(indexingStarted()), this, SLOT(indexingStarted()));
     connect(searchEngine, SIGNAL(indexingFinished()), this, SLOT(indexingFinished()));
 
@@ -153,11 +159,9 @@ MainWindow::MainWindow(CmdLineParser *cmdLine, QWidget *parent)
         connect(m_bookmarkManager, SIGNAL(bookmarksChanged()), this,
             SLOT(updateBookmarkMenu()));
 
-        const QString windowTitle =
-            CollectionConfiguration::windowTitle(*m_helpEngine);
+        const QString windowTitle = helpEngineWrapper.windowTitle();
         setWindowTitle(windowTitle.isEmpty() ? defWindowTitle : windowTitle);
-        QByteArray iconArray =
-            CollectionConfiguration::applicationIcon(*m_helpEngine);
+        QByteArray iconArray = helpEngineWrapper.applicationIcon();
         if (iconArray.size() > 0) {
             QPixmap pix;
             pix.loadFromData(iconArray);
@@ -171,11 +175,11 @@ MainWindow::MainWindow(CmdLineParser *cmdLine, QWidget *parent)
         // Show the widget here, otherwise the restore geometry and state won't work
         // on x11.
         show();
-        QByteArray ba(CollectionConfiguration::mainWindow(*m_helpEngine));
+        QByteArray ba(helpEngineWrapper.mainWindow());
         if (!ba.isEmpty())
             restoreState(ba);
 
-        ba = CollectionConfiguration::mainWindowGeometry(*m_helpEngine);
+        ba = helpEngineWrapper.mainWindowGeometry();
         if (!ba.isEmpty()) {
             restoreGeometry(ba);
         } else {
@@ -185,15 +189,13 @@ MainWindow::MainWindow(CmdLineParser *cmdLine, QWidget *parent)
             resize(QSize(800, 600));
         }
 
-        if (!CollectionConfiguration::hasFontSettings(*m_helpEngine)) {
-            CollectionConfiguration::setUseAppFont(*m_helpEngine, false);
-            CollectionConfiguration::setUseBrowserFont(*m_helpEngine, false);
-            CollectionConfiguration::setAppFont(*m_helpEngine, qApp->font());
-            CollectionConfiguration::setAppWritingSystem(*m_helpEngine,
-                QFontDatabase::Latin);
-            CollectionConfiguration::setBrowserFont(*m_helpEngine, qApp->font());
-            CollectionConfiguration::setBrowserWritingSystem(*m_helpEngine,
-                QFontDatabase::Latin);
+        if (!helpEngineWrapper.hasFontSettings()) {
+            helpEngineWrapper.setUseAppFont(false);
+            helpEngineWrapper.setUseBrowserFont(false);
+            helpEngineWrapper.setAppFont(qApp->font());
+            helpEngineWrapper.setAppWritingSystem(QFontDatabase::Latin);
+            helpEngineWrapper.setBrowserFont(qApp->font());
+            helpEngineWrapper.setBrowserWritingSystem(QFontDatabase::Latin);
         } else {
             updateApplicationFont();
         }
@@ -202,7 +204,7 @@ MainWindow::MainWindow(CmdLineParser *cmdLine, QWidget *parent)
 
         QTimer::singleShot(0, this, SLOT(insertLastPages()));
         if (m_cmdLine->enableRemoteControl())
-            (void)new RemoteControl(this, m_helpEngine, m_qchWatcher);
+            (void)new RemoteControl(this);
 
         if (m_cmdLine->contents() == CmdLineParser::Show)
             showContents();
@@ -233,8 +235,8 @@ MainWindow::MainWindow(CmdLineParser *cmdLine, QWidget *parent)
 
         if (!m_cmdLine->currentFilter().isEmpty()) {
             const QString &curFilter = m_cmdLine->currentFilter();
-            if (m_helpEngine->customFilters().contains(curFilter))
-                m_helpEngine->setCurrentFilter(curFilter);
+            if (helpEngineWrapper.customFilters().contains(curFilter))
+                helpEngineWrapper.setCurrentFilter(curFilter);
         }
 
         if (usesDefaultCollection())
@@ -242,12 +244,11 @@ MainWindow::MainWindow(CmdLineParser *cmdLine, QWidget *parent)
         else
             checkInitState();
 
-        foreach(const QString &ns, m_helpEngine->registeredDocumentations()) {
-            const QString &docFile = m_helpEngine->documentationFileName(ns);
-            m_qchWatcher->addPath(docFile);
-            connect(m_qchWatcher, SIGNAL(fileChanged(QString)), this,
-                    SLOT(qchFileChanged(QString)));
-        }
+        helpEngineWrapper.initFileSystemWatchers();
+        connect(&helpEngineWrapper, SIGNAL(documentationRemoved(QString)),
+                this, SLOT(documentationRemoved(QString)));
+        connect(&helpEngineWrapper, SIGNAL(documentationUpdated(QString)),
+                this, SLOT(documentationUpdated(QString)));
     }
     setTabPosition(Qt::AllDockWidgetAreas, QTabWidget::North);
 }
@@ -266,21 +267,20 @@ bool MainWindow::usesDefaultCollection() const
 void MainWindow::closeEvent(QCloseEvent *e)
 {
     m_bookmarkManager->saveBookmarks();
-    CollectionConfiguration::setMainWindow(*m_helpEngine, saveState());
-    CollectionConfiguration::setMainWindowGeometry(*m_helpEngine,
-        saveGeometry());
-
+    HelpEngineWrapper::instance().setMainWindow(saveState());
+    HelpEngineWrapper::instance().setMainWindowGeometry(saveGeometry());
     QMainWindow::closeEvent(e);
 }
 
 bool MainWindow::initHelpDB()
 {
-    if (!m_helpEngine->setupData())
+    HelpEngineWrapper &helpEngineWrapper = HelpEngineWrapper::instance();
+    if (!helpEngineWrapper.setupData())
         return false;
 
     bool assistantInternalDocRegistered = false;
     QString intern(QLatin1String("com.trolltech.com.assistantinternal-"));
-    foreach (const QString &ns, m_helpEngine->registeredDocumentations()) {
+    foreach (const QString &ns, helpEngineWrapper.registeredDocumentations()) {
         if (ns.startsWith(intern)) {
             intern = ns;
             assistantInternalDocRegistered = true;
@@ -288,8 +288,7 @@ bool MainWindow::initHelpDB()
         }
     }
 
-    const QString &collectionFile = m_helpEngine->collectionFile();
-
+    const QString &collectionFile = helpEngineWrapper.collectionFile();
     QFileInfo fi(collectionFile);
     QString helpFile;
     QTextStream(&helpFile) << fi.absolutePath() << QDir::separator()
@@ -306,62 +305,52 @@ bool MainWindow::initHelpDB()
 
             file.close();
         }
-        QHelpEngineCore hc(fi.absoluteFilePath());
-        hc.setupData();
-        const QString internalFile = hc.documentationFileName(intern);
-        if (hc.unregisterDocumentation(intern))
-            m_qchWatcher->removePath(internalFile);
-        if (hc.registerDocumentation(helpFile))
-            m_qchWatcher->addPath(helpFile);
+        helpEngineWrapper.unregisterDocumentation(intern);
+        helpEngineWrapper.registerDocumentation(helpFile);
         needsSetup = true;
     }
 
-    if (!CollectionConfiguration::unfilteredInserted(*m_helpEngine)) {
-        {
-            QHelpEngineCore hc(collectionFile);
-            hc.setupData();
-            hc.addCustomFilter(tr("Unfiltered"), QStringList());
-            CollectionConfiguration::setUnfilteredInserted(hc);
-        }
-
-        m_helpEngine->blockSignals(true);
-        m_helpEngine->setCurrentFilter(tr("Unfiltered"));
-        m_helpEngine->blockSignals(false);
+    if (!helpEngineWrapper.unfilteredInserted()) {
+        helpEngineWrapper.addCustomFilter(tr("Unfiltered"), QStringList());
+        helpEngineWrapper.setUnfilteredInserted();
+        helpEngineWrapper.setCurrentFilter(tr("Unfiltered"));
         needsSetup = true;
     }
 
-    if (needsSetup) {
-        m_helpEngine->setupData();
-        Q_ASSERT(m_qchWatcher->files().count()
-                 == m_helpEngine->registeredDocumentations().count());
-    }
+    if (needsSetup)
+        helpEngineWrapper.setupData();
     return true;
 }
 
 void MainWindow::lookForNewQtDocumentation()
 {
-    m_qtDocInstaller =
-        new QtDocInstaller(m_helpEngine->collectionFile(), m_qchWatcher);
-    connect(m_qtDocInstaller, SIGNAL(errorMessage(QString)), this,
-        SLOT(displayInstallationError(QString)));
+    HelpEngineWrapper &helpEngine = HelpEngineWrapper::instance();
+    QStringList docs;
+    docs << QLatin1String("assistant")
+        << QLatin1String("designer")
+        << QLatin1String("linguist")
+        << QLatin1String("qmake")
+        << QLatin1String("qt");
+    QList<QtDocInstaller::DocInfo> qtDocInfos;
+    foreach (const QString &doc, docs)
+        qtDocInfos.append(QtDocInstaller::DocInfo(doc, helpEngine.qtDocInfo(doc)));
+
+    m_qtDocInstaller = new QtDocInstaller(qtDocInfos);
     connect(m_qtDocInstaller, SIGNAL(docsInstalled(bool)), this,
         SLOT(qtDocumentationInstalled(bool)));
-
-    if (CollectionConfiguration::qtDocInfo(*m_helpEngine, QLatin1String("qt")).
-        count() != 2)
+    connect(m_qtDocInstaller, SIGNAL(qchFileNotFound(QString)), this,
+            SLOT(resetQtDocInfo(QString)));
+    connect(m_qtDocInstaller, SIGNAL(registerDocumentation(QString, QString)),
+            this, SLOT(registerDocumentation(QString, QString)));
+    if (helpEngine.qtDocInfo(QLatin1String("qt")).count() != 2)
         statusBar()->showMessage(tr("Looking for Qt Documentation..."));
     m_qtDocInstaller->installDocs();
 }
 
-void MainWindow::displayInstallationError(const QString &errorMessage)
-{
-    QMessageBox::warning(this, tr("Qt Assistant"), errorMessage);
-}
-
 void MainWindow::qtDocumentationInstalled(bool newDocsInstalled)
 {
     if (newDocsInstalled)
-        m_helpEngine->setupData();
+        HelpEngineWrapper::instance().setupData();
     statusBar()->clearMessage();
     checkInitState();
 }
@@ -371,19 +360,20 @@ void MainWindow::checkInitState()
     if (!m_cmdLine->enableRemoteControl())
         return;
 
-    if (m_helpEngine->contentModel()->isCreatingContents()
-        || m_helpEngine->indexModel()->isCreatingIndex()) {
+    HelpEngineWrapper &helpEngine = HelpEngineWrapper::instance();
+    if (helpEngine.contentModel()->isCreatingContents()
+        || helpEngine.indexModel()->isCreatingIndex()) {
         if (!m_connectedInitSignals) {
-            connect(m_helpEngine->contentModel(), SIGNAL(contentsCreated()),
+            connect(helpEngine.contentModel(), SIGNAL(contentsCreated()),
                 this, SLOT(checkInitState()));
-            connect(m_helpEngine->indexModel(), SIGNAL(indexCreated()), this,
+            connect(helpEngine.indexModel(), SIGNAL(indexCreated()), this,
                 SLOT(checkInitState()));
             m_connectedInitSignals = true;
         }
     } else {
         if (m_connectedInitSignals) {
-            disconnect(m_helpEngine->contentModel(), 0, this, 0);
-            disconnect(m_helpEngine->indexModel(), 0, this, 0);
+            disconnect(helpEngine.contentModel(), 0, this, 0);
+            disconnect(helpEngine.indexModel(), 0, this, 0);
         }
         emit initDone();
     }
@@ -663,7 +653,8 @@ QMenu *MainWindow::toolBarMenu()
 
 void MainWindow::setupFilterToolbar()
 {
-    if (!CollectionConfiguration::filterFunctionalityEnabled(*m_helpEngine))
+    HelpEngineWrapper &helpEngine = HelpEngineWrapper::instance();
+    if (!helpEngine.filterFunctionalityEnabled())
         return;
 
     m_filterCombo = new QComboBox(this);
@@ -676,15 +667,15 @@ void MainWindow::setupFilterToolbar()
         this));
     filterToolBar->addWidget(m_filterCombo);
 
-    if (!CollectionConfiguration::filterToolbarVisible(*m_helpEngine))
+    if (!helpEngine.filterToolbarVisible())
         filterToolBar->hide();
     toolBarMenu()->addAction(filterToolBar->toggleViewAction());
 
-    connect(m_helpEngine, SIGNAL(setupFinished()), this,
-        SLOT(setupFilterCombo()));
+    connect(&helpEngine, SIGNAL(setupFinished()), this,
+        SLOT(setupFilterCombo()), Qt::QueuedConnection);
     connect(m_filterCombo, SIGNAL(activated(QString)), this,
         SLOT(filterDocumentation(QString)));
-    connect(m_helpEngine, SIGNAL(currentFilterChanged(QString)), this,
+    connect(&helpEngine, SIGNAL(currentFilterChanged(QString)), this,
         SLOT(currentFilterChanged(QString)));
 
     setupFilterCombo();
@@ -692,7 +683,8 @@ void MainWindow::setupFilterToolbar()
 
 void MainWindow::setupAddressToolbar()
 {
-    if (!CollectionConfiguration::addressBarEnabled(*m_helpEngine))
+    HelpEngineWrapper &helpEngine = HelpEngineWrapper::instance();
+    if (!helpEngine.addressBarEnabled())
         return;
 
     m_addressLineEdit = new QLineEdit(this);
@@ -704,7 +696,7 @@ void MainWindow::setupAddressToolbar()
         this));
     addressToolBar->addWidget(m_addressLineEdit);
 
-    if (!CollectionConfiguration::addressBarVisible(*m_helpEngine))
+    if (!helpEngine.addressBarVisible())
         addressToolBar->hide();
     toolBarMenu()->addAction(addressToolBar->toggleViewAction());
 
@@ -719,30 +711,28 @@ void MainWindow::setupAddressToolbar()
 
 void MainWindow::updateAboutMenuText()
 {
-    if (m_helpEngine) {
-        QByteArray ba = CollectionConfiguration::aboutMenuTexts(*m_helpEngine);
-        if (ba.size() > 0) {
-            QString lang;
-            QString str;
-            QString trStr;
-            QString currentLang = QLocale::system().name();
-            int i = currentLang.indexOf(QLatin1Char('_'));
-            if (i > -1)
-                currentLang = currentLang.left(i);
-            QDataStream s(&ba, QIODevice::ReadOnly);
-            while (!s.atEnd()) {
-                s >> lang;
-                s >> str;
-                if (lang == QLatin1String("default") && trStr.isEmpty()) {
-                    trStr = str;
-                } else if (lang == currentLang) {
-                    trStr = str;
-                    break;
-                }
+    QByteArray ba = HelpEngineWrapper::instance().aboutMenuTexts();
+    if (ba.size() > 0) {
+        QString lang;
+        QString str;
+        QString trStr;
+        QString currentLang = QLocale::system().name();
+        int i = currentLang.indexOf(QLatin1Char('_'));
+        if (i > -1)
+            currentLang = currentLang.left(i);
+        QDataStream s(&ba, QIODevice::ReadOnly);
+        while (!s.atEnd()) {
+            s >> lang;
+            s >> str;
+            if (lang == QLatin1String("default") && trStr.isEmpty()) {
+                trStr = str;
+            } else if (lang == currentLang) {
+                trStr = str;
+                break;
             }
-            if (!trStr.isEmpty())
-                m_aboutAction->setText(trStr);
         }
+        if (!trStr.isEmpty())
+            m_aboutAction->setText(trStr);
     }
 }
 
@@ -796,7 +786,7 @@ void MainWindow::showTopicChooser(const QMap<QString, QUrl> &links,
 
 void MainWindow::showPreferences()
 {
-    PreferencesDialog dia(m_helpEngine, m_qchWatcher, this);
+    PreferencesDialog dia(this);
 
     connect(&dia, SIGNAL(updateApplicationFont()), this,
         SLOT(updateApplicationFont()));
@@ -832,26 +822,25 @@ void MainWindow::addNewBookmark(const QString &title, const QString &url)
 
 void MainWindow::showAboutDialog()
 {
+    HelpEngineWrapper &helpEngine = HelpEngineWrapper::instance();
     QByteArray contents;
-    if (m_helpEngine) {
-        QByteArray ba = CollectionConfiguration::aboutTexts(*m_helpEngine);
-        if (!ba.isEmpty()) {
-            QString lang;
-            QByteArray cba;
-            QString currentLang = QLocale::system().name();
-            int i = currentLang.indexOf(QLatin1Char('_'));
-            if (i > -1)
-                currentLang = currentLang.left(i);
-            QDataStream s(&ba, QIODevice::ReadOnly);
-            while (!s.atEnd()) {
-                s >> lang;
-                s >> cba;
-                if (lang == QLatin1String("default") && contents.isEmpty()) {
-                    contents = cba;
-                } else if (lang == currentLang) {
-                    contents = cba;
-                    break;
-                }
+    QByteArray ba = helpEngine.aboutTexts();
+    if (!ba.isEmpty()) {
+        QString lang;
+        QByteArray cba;
+        QString currentLang = QLocale::system().name();
+        int i = currentLang.indexOf(QLatin1Char('_'));
+        if (i > -1)
+            currentLang = currentLang.left(i);
+        QDataStream s(&ba, QIODevice::ReadOnly);
+        while (!s.atEnd()) {
+            s >> lang;
+            s >> cba;
+            if (lang == QLatin1String("default") && contents.isEmpty()) {
+                contents = cba;
+            } else if (lang == currentLang) {
+                contents = cba;
+                break;
             }
         }
     }
@@ -860,9 +849,8 @@ void MainWindow::showAboutDialog()
 
     QByteArray iconArray;
     if (!contents.isEmpty()) {
-        iconArray = CollectionConfiguration::aboutIcon(*m_helpEngine);
-        QByteArray resources =
-            CollectionConfiguration::aboutImages(*m_helpEngine);
+        iconArray = helpEngine.aboutIcon();
+        QByteArray resources = helpEngine.aboutImages();
         QPixmap pix;
         pix.loadFromData(iconArray);
         aboutDia.setText(QString::fromUtf8(contents), resources);
@@ -990,20 +978,22 @@ void MainWindow::showSearchWidget()
 
 void MainWindow::updateApplicationFont()
 {
+    HelpEngineWrapper &helpEngine = HelpEngineWrapper::instance();
     QFont font = qApp->font();
-    if (CollectionConfiguration::usesAppFont(*m_helpEngine))
-        font = CollectionConfiguration::appFont(*m_helpEngine);
+    if (helpEngine.usesAppFont())
+        font = helpEngine.appFont();
 
     qApp->setFont(font, "QWidget");
 }
 
 void MainWindow::setupFilterCombo()
 {
+    HelpEngineWrapper &helpEngine = HelpEngineWrapper::instance();
     QString curFilter = m_filterCombo->currentText();
     if (curFilter.isEmpty())
-        curFilter = m_helpEngine->currentFilter();
+        curFilter = helpEngine.currentFilter();
     m_filterCombo->clear();
-    m_filterCombo->addItems(m_helpEngine->customFilters());
+    m_filterCombo->addItems(helpEngine.customFilters());
     int idx = m_filterCombo->findText(curFilter);
     if (idx < 0)
         idx = 0;
@@ -1012,7 +1002,7 @@ void MainWindow::setupFilterCombo()
 
 void MainWindow::filterDocumentation(const QString &customFilter)
 {
-    m_helpEngine->setCurrentFilter(customFilter);
+    HelpEngineWrapper::instance().setCurrentFilter(customFilter);
 }
 
 void MainWindow::expandTOC(int depth)
@@ -1055,7 +1045,7 @@ void MainWindow::indexingFinished()
 
 QWidget* MainWindow::setupBookmarkWidget()
 {
-    m_bookmarkManager = new BookmarkManager(m_helpEngine);
+    m_bookmarkManager = new BookmarkManager;
     m_bookmarkWidget = new BookmarkWidget(m_bookmarkManager, this);
     connect(m_bookmarkWidget, SIGNAL(addBookmark()), this, SLOT(addBookmark()));
     return m_bookmarkWidget;
@@ -1135,33 +1125,45 @@ void MainWindow::currentFilterChanged(const QString &filter)
     m_filterCombo->setCurrentIndex(index);
 }
 
-void MainWindow::qchFileChanged(const QString &fileName)
+void MainWindow::documentationRemoved(const QString &namespaceName)
 {
-    /*
-     * We don't use QHelpEngineCore::namespaceName(fileName), because the file
-     * may not exist anymore or contain a different namespace.
-     */
-    QString ns;
-    foreach (const QString &curNs, m_helpEngine->registeredDocumentations()) {
-        if (m_helpEngine->documentationFileName(curNs) == fileName) {
-            ns = curNs;
-            break;
-        }
-    }
+    CentralWidget* widget = CentralWidget::instance();
+    widget->closeTabs(widget->currentSourceFileList().keys(namespaceName));
+}
+
+void MainWindow::documentationUpdated(const QString &namespaceName)
+{
+    // TODO: Check whether the documents still exists and if they do, reload.
+    CentralWidget* widget = CentralWidget::instance();
+    widget->closeTabs(widget->currentSourceFileList().keys(namespaceName));
+}
 
-    /*
-     * We can't do an assertion here, because QFileSystemWatcher may send the
-     * signal more than  once.
-     */
+void MainWindow::resetQtDocInfo(const QString &component)
+{
+    HelpEngineWrapper::instance().setQtDocInfo(component,
+        QStringList(QDateTime().toString(Qt::ISODate)));
+}
+
+void MainWindow::registerDocumentation(const QString &component,
+                                       const QString &absFileName)
+{
+    QString ns = QHelpEngineCore::namespaceName(absFileName);
     if (ns.isEmpty())
         return;
 
-    CentralWidget* widget = CentralWidget::instance();
-    widget->closeTabs(widget->currentSourceFileList().keys(ns));
-    if (m_helpEngine->unregisterDocumentation(ns) &&
-        (!QFileInfo(fileName).exists()
-         || !m_helpEngine->registerDocumentation(fileName)))
-        m_qchWatcher->removePath(fileName);
+    HelpEngineWrapper &helpEngine = HelpEngineWrapper::instance();
+    if (helpEngine.registeredDocumentations().contains(ns))
+        helpEngine.unregisterDocumentation(ns);
+    if (!helpEngine.registerDocumentation(absFileName)) {
+        QMessageBox::warning(this, tr("Qt Assistant"),
+            tr("Could not register file '%1': %2").
+            arg(absFileName).arg(helpEngine.error()));
+    } else {
+        QStringList docInfo;
+        docInfo << QFileInfo(absFileName).lastModified().toString(Qt::ISODate)
+                << absFileName;
+        helpEngine.setQtDocInfo(component, docInfo);
+    }
 }
 
 QT_END_NAMESPACE
diff --git a/tools/assistant/tools/assistant/mainwindow.h b/tools/assistant/tools/assistant/mainwindow.h
index 6a0ab58..65eadd7 100644
--- a/tools/assistant/tools/assistant/mainwindow.h
+++ b/tools/assistant/tools/assistant/mainwindow.h
@@ -117,10 +117,13 @@ private slots:
     void lookForNewQtDocumentation();
     void indexingStarted();
     void indexingFinished();
-    void displayInstallationError(const QString &errorMessage);
     void qtDocumentationInstalled(bool newDocsInstalled);
+    void registerDocumentation(const QString &component,
+                               const QString &absFileName);
+    void resetQtDocInfo(const QString &component);
     void checkInitState();
-    void qchFileChanged(const QString &fileName);
+    void documentationRemoved(const QString &namespaceName);
+    void documentationUpdated(const QString &namespaceName);
 
     void updateBookmarkMenu();
     void showBookmark(QAction *action);
@@ -143,7 +146,6 @@ private:
     void hideBookmarks();
     void hideSearch();
 
-    QHelpEngine *m_helpEngine;
     CentralWidget *m_centralWidget;
     IndexWindow *m_indexWindow;
     ContentWindow *m_contentWindow;
@@ -179,7 +181,6 @@ private:
 
     QWidget *m_progressWidget;
     QtDocInstaller *m_qtDocInstaller;
-    QFileSystemWatcher * const m_qchWatcher;
 
     bool m_connectedInitSignals;
 };
diff --git a/tools/assistant/tools/assistant/preferencesdialog.cpp b/tools/assistant/tools/assistant/preferencesdialog.cpp
index 10d6dd9..2f282b1 100644
--- a/tools/assistant/tools/assistant/preferencesdialog.cpp
+++ b/tools/assistant/tools/assistant/preferencesdialog.cpp
@@ -45,7 +45,7 @@
 #include "fontpanel.h"
 #include "centralwidget.h"
 #include "aboutdialog.h"
-#include "../shared/collectionconfiguration.h"
+#include "helpenginewrapper.h"
 
 #include <QtCore/QtAlgorithms>
 #include <QtCore/QFileSystemWatcher>
@@ -62,13 +62,11 @@
 
 QT_BEGIN_NAMESPACE
 
-PreferencesDialog::PreferencesDialog(QHelpEngineCore *helpEngine,
-    QFileSystemWatcher *qchWatcher, QWidget *parent)
+PreferencesDialog::PreferencesDialog(QWidget *parent)
     : QDialog(parent)
-    , m_helpEngine(helpEngine)
     , m_appFontChanged(false)
     , m_browserFontChanged(false)
-    , m_qchWatcher(qchWatcher)
+    , helpEngine(HelpEngineWrapper::instance())
 {
     m_ui.setupUi(this);
 
@@ -77,10 +75,8 @@ PreferencesDialog::PreferencesDialog(QHelpEngineCore *helpEngine,
     connect(m_ui.buttonBox->button(QDialogButtonBox::Cancel), SIGNAL(clicked()),
         this, SLOT(reject()));
 
-    m_hideFiltersTab =
-        !CollectionConfiguration::filterFunctionalityEnabled(*m_helpEngine);
-    m_hideDocsTab =
-        !CollectionConfiguration::documentationManagerEnabled(*m_helpEngine);
+    m_hideFiltersTab = !helpEngine.filterFunctionalityEnabled();
+    m_hideDocsTab = !helpEngine.documentationManagerEnabled();
 
     if (!m_hideFiltersTab) {
         m_ui.attributeWidget->header()->hide();
@@ -109,7 +105,7 @@ PreferencesDialog::PreferencesDialog(QHelpEngineCore *helpEngine,
         connect(m_ui.docRemoveButton, SIGNAL(clicked()), this,
             SLOT(removeDocumentation()));
 
-        m_docsBackup = m_helpEngine->registeredDocumentations();
+        m_docsBackup = helpEngine.registeredDocumentations();
         m_ui.registeredDocsListWidget->addItems(m_docsBackup);
     } else {
         m_ui.tabWidget->removeTab(m_ui.tabWidget->indexOf(m_ui.docsTab));
@@ -122,21 +118,15 @@ PreferencesDialog::PreferencesDialog(QHelpEngineCore *helpEngine,
 PreferencesDialog::~PreferencesDialog()
 {
     if (m_appFontChanged) {
-        CollectionConfiguration::setAppFont(*m_helpEngine,
-            m_appFontPanel->selectedFont());
-        CollectionConfiguration::setUseAppFont(*m_helpEngine,
-            m_appFontPanel->isChecked());
-        CollectionConfiguration::setAppWritingSystem(*m_helpEngine,
-            m_appFontPanel->writingSystem());
+        helpEngine.setAppFont(m_appFontPanel->selectedFont());
+        helpEngine.setUseAppFont(m_appFontPanel->isChecked());
+        helpEngine.setAppWritingSystem(m_appFontPanel->writingSystem());
     }
 
     if (m_browserFontChanged) {
-        CollectionConfiguration::setBrowserFont(*m_helpEngine,
-            m_browserFontPanel->selectedFont());
-        CollectionConfiguration::setUseBrowserFont(*m_helpEngine,
-            m_browserFontPanel->isChecked());
-        CollectionConfiguration::setBrowserWritingSystem(*m_helpEngine,
-            m_browserFontPanel->writingSystem());
+        helpEngine.setBrowserFont(m_browserFontPanel->selectedFont());
+        helpEngine.setUseBrowserFont(m_browserFontPanel->isChecked());
+        helpEngine.setBrowserWritingSystem(m_browserFontPanel->writingSystem());
     }
 
     if (m_appFontChanged || m_browserFontChanged) {
@@ -147,10 +137,10 @@ PreferencesDialog::~PreferencesDialog()
     QString homePage = m_ui.homePageLineEdit->text();
     if (homePage.isEmpty())
         homePage = QLatin1String("help");
-    CollectionConfiguration::setHomePage(*m_helpEngine, homePage);
+    helpEngine.setHomePage(homePage);
 
     int option = m_ui.helpStartComboBox->currentIndex();
-    CollectionConfiguration::setStartOption(*m_helpEngine, option);
+    helpEngine.setStartOption(option);
 }
 
 void PreferencesDialog::showDialog()
@@ -161,18 +151,13 @@ void PreferencesDialog::showDialog()
 
 void PreferencesDialog::updateFilterPage()
 {
-    if (!m_helpEngine)
-        return;
-
     m_ui.filterWidget->clear();
     m_ui.attributeWidget->clear();
 
-    QHelpEngineCore help(m_helpEngine->collectionFile(), 0);
-    help.setupData();
     m_filterMapBackup.clear();
-    const QStringList filters = help.customFilters();
+    const QStringList filters = helpEngine.customFilters();
     foreach (const QString &filter, filters) {
-        QStringList atts = help.filterAttributes(filter);
+        QStringList atts = helpEngine.filterAttributes(filter);
         m_filterMapBackup.insert(filter, atts);
         if (!m_filterMap.contains(filter))
             m_filterMap.insert(filter, atts);
@@ -180,10 +165,10 @@ void PreferencesDialog::updateFilterPage()
 
     m_ui.filterWidget->addItems(m_filterMap.keys());
 
-    foreach (const QString &a, help.filterAttributes())
+    foreach (const QString &a, helpEngine.filterAttributes())
         new QTreeWidgetItem(m_ui.attributeWidget, QStringList() << a);
 
-    if (m_filterMap.keys().count())
+    if (!m_filterMap.keys().isEmpty())
         m_ui.filterWidget->setCurrentRow(0);
 }
 
@@ -273,14 +258,11 @@ void PreferencesDialog::addDocumentationLocal()
                 continue;
         }
 
-        if (m_helpEngine->registerDocumentation(fileName)) {
-            m_qchWatcher->addPath(fileName);
-            Q_ASSERT(m_qchWatcher->files().count()
-                     == m_helpEngine->registeredDocumentations().count());
+        if (helpEngine.registerDocumentation(fileName)) {
+            m_ui.registeredDocsListWidget->addItem(nameSpace);
+            m_regDocs.append(nameSpace);
+            m_unregDocs.removeAll(nameSpace);
         }
-        m_ui.registeredDocsListWidget->addItem(nameSpace);
-        m_regDocs.append(nameSpace);
-        m_unregDocs.removeAll(nameSpace);
     }
 
     if (!invalidFiles.isEmpty() || !alreadyRegistered.isEmpty()) {
@@ -372,26 +354,21 @@ void PreferencesDialog::applyChanges()
 
     if (filtersWereChanged) {
         foreach (const QString &filter, m_removedFilters)
-            m_helpEngine->removeCustomFilter(filter);
+            helpEngine.removeCustomFilter(filter);
         QMapIterator<QString, QStringList> it(m_filterMap);
         while (it.hasNext()) {
             it.next();
-            m_helpEngine->addCustomFilter(it.key(), it.value());
+            helpEngine.addCustomFilter(it.key(), it.value());
         }
     }
 
     CentralWidget::instance()->closeTabs(m_TabsToClose);
 
-    foreach (const QString &doc, m_unregDocs) {
-        const QString docFile = m_helpEngine->documentationFileName(doc);
-        if (m_helpEngine->unregisterDocumentation(doc))
-            m_qchWatcher->removePath(docFile);
-    }
-    Q_ASSERT(m_qchWatcher->files().count()
-             == m_helpEngine->registeredDocumentations().count());
+    foreach (const QString &doc, m_unregDocs)
+        helpEngine.unregisterDocumentation(doc);
 
-    if (filtersWereChanged || m_regDocs.count() || m_unregDocs.count())
-        m_helpEngine->setupData();
+    if (filtersWereChanged || !m_regDocs.isEmpty() || !m_unregDocs.isEmpty())
+        helpEngine.setupData();
 
     accept();
 }
@@ -411,26 +388,23 @@ void PreferencesDialog::updateFontSettingsPage()
     const QString customSettings(tr("Use custom settings"));
     m_appFontPanel->setTitle(customSettings);
 
-    QFont font = CollectionConfiguration::appFont(*m_helpEngine);
+    QFont font = helpEngine.appFont();
     m_appFontPanel->setSelectedFont(font);
 
-    QFontDatabase::WritingSystem system =
-        CollectionConfiguration::appWritingSystem(*m_helpEngine);
+    QFontDatabase::WritingSystem system = helpEngine.appWritingSystem();
     m_appFontPanel->setWritingSystem(system);
 
-    m_appFontPanel->setChecked(CollectionConfiguration::
-                               usesAppFont(*m_helpEngine));
+    m_appFontPanel->setChecked(helpEngine.usesAppFont());
 
     m_browserFontPanel->setTitle(customSettings);
 
-    font = CollectionConfiguration::browserFont(*m_helpEngine);
+    font = helpEngine.browserFont();
     m_browserFontPanel->setSelectedFont(font);
 
-    system = CollectionConfiguration::browserWritingSystem(*m_helpEngine);
+    system = helpEngine.browserWritingSystem();
     m_browserFontPanel->setWritingSystem(system);
 
-    m_browserFontPanel->setChecked(CollectionConfiguration::
-                                   usesBrowserFont(*m_helpEngine));
+    m_browserFontPanel->setChecked(helpEngine.usesBrowserFont());
 
     connect(m_appFontPanel, SIGNAL(toggled(bool)), this,
         SLOT(appFontSettingToggled(bool)));
@@ -476,12 +450,9 @@ void PreferencesDialog::browserFontSettingChanged(int index)
 
 void PreferencesDialog::updateOptionsPage()
 {
-    QString homePage = CollectionConfiguration::homePage(*m_helpEngine);
-    if (homePage.isEmpty())
-        homePage = CollectionConfiguration::defaultHomePage(*m_helpEngine);
-    m_ui.homePageLineEdit->setText(homePage);
+    m_ui.homePageLineEdit->setText(helpEngine.homePage());
 
-    int option = CollectionConfiguration::startOption(*m_helpEngine);
+    int option = helpEngine.startOption();
     m_ui.helpStartComboBox->setCurrentIndex(option);
 
     connect(m_ui.blankPageButton, SIGNAL(clicked()), this, SLOT(setBlankPage()));
@@ -505,8 +476,7 @@ void PreferencesDialog::setCurrentPage()
 
 void PreferencesDialog::setDefaultPage()
 {
-    QString homePage = CollectionConfiguration::defaultHomePage(*m_helpEngine);
-    m_ui.homePageLineEdit->setText(homePage);
+    m_ui.homePageLineEdit->setText(helpEngine.defaultHomePage());
 }
 
 QT_END_NAMESPACE
diff --git a/tools/assistant/tools/assistant/preferencesdialog.h b/tools/assistant/tools/assistant/preferencesdialog.h
index 7abf431..1554a9f 100644
--- a/tools/assistant/tools/assistant/preferencesdialog.h
+++ b/tools/assistant/tools/assistant/preferencesdialog.h
@@ -48,22 +48,15 @@
 QT_BEGIN_NAMESPACE
 
 class FontPanel;
+class HelpEngineWrapper;
 class QFileSystemWatcher;
-class QHelpEngineCore;
-
-enum {
-    ShowHomePage = 0,
-    ShowBlankPage = 1,
-    ShowLastPages = 2
-};
 
 class PreferencesDialog : public QDialog
 {
     Q_OBJECT
 
 public:
-    PreferencesDialog(QHelpEngineCore *helpEngine,
-                      QFileSystemWatcher *qchWatcher, QWidget *parent = 0);
+    PreferencesDialog(QWidget *parent = 0);
     ~PreferencesDialog();
 
     void showDialog();
@@ -95,7 +88,6 @@ private:
     void updateOptionsPage();
 
     Ui::PreferencesDialogClass m_ui;
-    QHelpEngineCore *m_helpEngine;
     bool m_hideFiltersTab;
     bool m_hideDocsTab;
     QMap<QString, QStringList> m_filterMapBackup;
@@ -109,7 +101,7 @@ private:
     FontPanel *m_browserFontPanel;
     bool m_appFontChanged;
     bool m_browserFontChanged;
-    QFileSystemWatcher * const m_qchWatcher;
+    HelpEngineWrapper &helpEngine;
 };
 
 QT_END_NAMESPACE
diff --git a/tools/assistant/tools/assistant/qtdocinstaller.cpp b/tools/assistant/tools/assistant/qtdocinstaller.cpp
index 3f82786..3675aec 100644
--- a/tools/assistant/tools/assistant/qtdocinstaller.cpp
+++ b/tools/assistant/tools/assistant/qtdocinstaller.cpp
@@ -44,17 +44,14 @@
 #include <QtCore/QDateTime>
 #include <QtCore/QFileSystemWatcher>
 #include <QtHelp/QHelpEngineCore>
-#include "../shared/collectionconfiguration.h"
+#include "helpenginewrapper.h"
 #include "qtdocinstaller.h"
 
 QT_BEGIN_NAMESPACE
 
-QtDocInstaller::QtDocInstaller(const QString &collectionFile,
-                               QFileSystemWatcher *qchWatcher)
-    : m_qchWatcher(qchWatcher)
+QtDocInstaller::QtDocInstaller(const QList<DocInfo> &docInfos)
+    : m_abort(false), m_docInfos(docInfos)
 {
-    m_abort = false;
-    m_collectionFile = collectionFile;
 }
 
 QtDocInstaller::~QtDocInstaller()
@@ -74,87 +71,51 @@ void QtDocInstaller::installDocs()
 
 void QtDocInstaller::run()
 {
-    QHelpEngineCore *helpEngine = new QHelpEngineCore(m_collectionFile);
-    helpEngine->setupData();
-    bool changes = false;
-
-    QStringList docs;
-    docs << QLatin1String("assistant")
-        << QLatin1String("designer")
-        << QLatin1String("linguist")
-        << QLatin1String("qmake")
-        << QLatin1String("qt");
+    m_qchDir = QLibraryInfo::location(QLibraryInfo::DocumentationPath)
+        + QDir::separator() + QLatin1String("qch");
+    m_qchFiles = m_qchDir.entryList(QStringList() << QLatin1String("*.qch"));
 
-    foreach (const QString &doc, docs) {
-        changes |= installDoc(doc, helpEngine);
+    bool changes = false;
+    foreach (const DocInfo &docInfo, m_docInfos) {
+        changes |= installDoc(docInfo);
         m_mutex.lock();
         if (m_abort) {
-            delete helpEngine;
             m_mutex.unlock();
             return;
         }
         m_mutex.unlock();
     }
-    delete helpEngine;
     emit docsInstalled(changes);
 }
 
-bool QtDocInstaller::installDoc(const QString &name, QHelpEngineCore *helpEngine)
+bool QtDocInstaller::installDoc(const DocInfo &docInfo)
 {
-    QStringList lst = CollectionConfiguration::qtDocInfo(*helpEngine, name);
-
+    const QString &component = docInfo.first;
+    const QStringList &info = docInfo.second;
     QDateTime dt;
-    if (!lst.isEmpty() && !lst.first().isEmpty())
-        dt = QDateTime::fromString(lst.first(), Qt::ISODate);
+    if (!info.isEmpty() && !info.first().isEmpty())
+        dt = QDateTime::fromString(info.first(), Qt::ISODate);
 
     QString qchFile;
-    if (lst.count() == 2)
-        qchFile = lst.last();
-
-    QDir dir(QLibraryInfo::location(QLibraryInfo::DocumentationPath)
-        + QDir::separator() + QLatin1String("qch"));
+    if (info.count() == 2)
+        qchFile = info.last();
 
-    const QStringList files = dir.entryList(QStringList() << QLatin1String("*.qch"));
-    if (files.isEmpty()) {
-        CollectionConfiguration::setQtDocInfo(*helpEngine, name,
-            QStringList(QDateTime().toString(Qt::ISODate)));
+    if (m_qchFiles.isEmpty()) {
+        emit qchFileNotFound(component);
         return false;
     }
-    foreach (const QString &f, files) {
-        if (f.startsWith(name)) {
-            QFileInfo fi(dir.absolutePath() + QDir::separator() + f);
+    foreach (const QString &f, m_qchFiles) {
+        if (f.startsWith(component)) {
+            QFileInfo fi(m_qchDir.absolutePath() + QDir::separator() + f);
             if (dt.isValid() && fi.lastModified().toTime_t() == dt.toTime_t()
                 && qchFile == fi.absoluteFilePath())
                 return false;
-
-            QString namespaceName = QHelpEngineCore::namespaceName(fi.absoluteFilePath());
-            if (namespaceName.isEmpty())
-                continue;
-
-            if (helpEngine->registeredDocumentations().contains(namespaceName)) {
-                const QString docFile =
-                    helpEngine->documentationFileName(namespaceName);
-                if (helpEngine->unregisterDocumentation(namespaceName))
-                    m_qchWatcher->removePath(docFile);
-            }
-
-            if (!helpEngine->registerDocumentation(fi.absoluteFilePath())) {
-                emit errorMessage(
-                    tr("The file %1 could not be registered successfully!\n\nReason: %2")
-                    .arg(fi.absoluteFilePath()).arg(helpEngine->error()));
-            } else {
-                m_qchWatcher->addPath(fi.absoluteFilePath());
-            }
-
-            Q_ASSERT(m_qchWatcher->files().count()
-                     == helpEngine->registeredDocumentations().count());
-
-            CollectionConfiguration::setQtDocInfo(*helpEngine, name,
-                QStringList() << fi.lastModified().toString(Qt::ISODate)
-                              << fi.absoluteFilePath());
+            emit registerDocumentation(component, fi.absoluteFilePath());
             return true;
         }
     }
+
+    emit qchFileNotFound(component);
     return false;
 }
 
diff --git a/tools/assistant/tools/assistant/qtdocinstaller.h b/tools/assistant/tools/assistant/qtdocinstaller.h
index 0d503fd..c64a5c3 100644
--- a/tools/assistant/tools/assistant/qtdocinstaller.h
+++ b/tools/assistant/tools/assistant/qtdocinstaller.h
@@ -42,36 +42,41 @@
 #ifndef QTDOCINSTALLER
 #define QTDOCINSTALLER
 
-#include <QtCore/QThread>
+#include <QtCore/QDir>
 #include <QtCore/QMutex>
+#include <QtCore/QPair>
+#include <QtCore/QStringList>
+#include <QtCore/QThread>
 
 QT_BEGIN_NAMESPACE
 
-class QFileSystemWatcher;
-class QHelpEngineCore;
+class HelpEngineWrapper;
 
 class QtDocInstaller : public QThread
 {
     Q_OBJECT
 
 public:
-    QtDocInstaller(const QString &collectionFile, QFileSystemWatcher *qchWatcher);
+    typedef QPair<QString, QStringList> DocInfo;
+    QtDocInstaller(const QList<DocInfo> &docInfos);
     ~QtDocInstaller();
     void installDocs();
 
 signals:
-    void errorMessage(const QString &msg);
+    void qchFileNotFound(const QString &component);
+    void registerDocumentation(const QString &component,
+                               const QString &absFileName);
     void docsInstalled(bool newDocsInstalled);
 
 private:
     void run();
-    bool installDoc(const QString &name,
-        QHelpEngineCore *helpEngine);
+    bool installDoc(const DocInfo &docInfo);
 
     bool m_abort;
-    QString m_collectionFile;
     QMutex m_mutex;
-    QFileSystemWatcher * const m_qchWatcher;
+    QStringList m_qchFiles;
+    QDir m_qchDir;
+    QList<DocInfo> m_docInfos;
 };
 
 QT_END_NAMESPACE
diff --git a/tools/assistant/tools/assistant/remotecontrol.cpp b/tools/assistant/tools/assistant/remotecontrol.cpp
index ef13885..f4ae3b4 100644
--- a/tools/assistant/tools/assistant/remotecontrol.cpp
+++ b/tools/assistant/tools/assistant/remotecontrol.cpp
@@ -42,6 +42,7 @@
 #include "remotecontrol.h"
 #include "mainwindow.h"
 #include "centralwidget.h"
+#include "helpenginewrapper.h"
 
 #include <QtCore/QFile>
 #include <QtCore/QFileInfo>
@@ -106,16 +107,14 @@ void StdInListenerWin::run()
 }
 #endif
 
-RemoteControl::RemoteControl(MainWindow *mainWindow, QHelpEngine *helpEngine,
-                             QFileSystemWatcher *qchWatcher)
+RemoteControl::RemoteControl(MainWindow *mainWindow)
     : QObject(mainWindow)
     , m_mainWindow(mainWindow)
-    , m_helpEngine(helpEngine)
     , m_debug(false)
     , m_caching(true)
     , m_syncContents(false)
     , m_expandTOC(-2)
-    , m_qchWatcher(qchWatcher)
+    , helpEngine(HelpEngineWrapper::instance())
 
 {
     connect(m_mainWindow, SIGNAL(initDone()), this, SLOT(applyCache()));
@@ -248,7 +247,7 @@ void RemoteControl::handleActivateKeywordCommand(const QString &arg)
     } else {
         m_mainWindow->setIndexString(arg);
         if (!arg.isEmpty())
-            m_helpEngine->indexWidget()->activateCurrentItem();
+            helpEngine.indexWidget()->activateCurrentItem();
     }
 }
 
@@ -258,8 +257,7 @@ void RemoteControl::handleActivateIdentifierCommand(const QString &arg)
         clearCache();
         m_activateIdentifier = arg;
     } else {
-        const QMap<QString, QUrl> &links =
-            m_helpEngine->linksForIdentifier(arg);
+        const QMap<QString, QUrl> &links = helpEngine.linksForIdentifier(arg);
         if (!links.isEmpty())
             CentralWidget::instance()->setSource(links.constBegin().value());
     }
@@ -282,12 +280,12 @@ void RemoteControl::handleExpandTocCommand(const QString &arg)
 
 void RemoteControl::handleSetCurrentFilterCommand(const QString &arg)
 {
-    if (m_helpEngine->customFilters().contains(arg)) {
+    if (helpEngine.customFilters().contains(arg)) {
         if (m_caching) {
             clearCache();
             m_currentFilter = arg;
         } else {
-            m_helpEngine->setCurrentFilter(arg);
+            helpEngine.setCurrentFilter(arg);
         }
     }
 }
@@ -295,29 +293,22 @@ void RemoteControl::handleSetCurrentFilterCommand(const QString &arg)
 void RemoteControl::handleRegisterCommand(const QString &arg)
 {
     const QString &absFileName = QFileInfo(arg).absoluteFilePath();
-    if (m_helpEngine->registeredDocumentations().
+    if (helpEngine.registeredDocumentations().
         contains(QHelpEngineCore::namespaceName(absFileName)))
         return;
-    if (m_helpEngine->registerDocumentation(absFileName)) {
-        m_qchWatcher->addPath(absFileName);
-        m_helpEngine->setupData();
-        Q_ASSERT(m_qchWatcher->files().count()
-                 == m_helpEngine->registeredDocumentations().count());
-    }
+    if (helpEngine.registerDocumentation(absFileName))
+        helpEngine.setupData();
 }
 
 void RemoteControl::handleUnregisterCommand(const QString &arg)
 {
     const QString &absFileName = QFileInfo(arg).absoluteFilePath();
     const QString &ns = QHelpEngineCore::namespaceName(absFileName);
-    if (m_helpEngine->registeredDocumentations().contains(ns)) {
+    if (helpEngine.registeredDocumentations().contains(ns)) {
         CentralWidget* widget = CentralWidget::instance();
         widget->closeTabs(widget->currentSourceFileList().keys(ns));
-        const QString docFile = m_helpEngine->documentationFileName(ns);
-        if (m_helpEngine->unregisterDocumentation(ns)) {
-            m_qchWatcher->removePath(docFile);
-            m_helpEngine->setupData();
-        }
+        if (helpEngine.unregisterDocumentation(ns))
+            helpEngine.setupData();
     }
 }
 
@@ -327,14 +318,14 @@ void RemoteControl::applyCache()
         CentralWidget::instance()->setSource(m_setSource);
     } else if (!m_activateKeyword.isEmpty()) {
         m_mainWindow->setIndexString(m_activateKeyword);
-        m_helpEngine->indexWidget()->activateCurrentItem();
+        helpEngine.indexWidget()->activateCurrentItem();
     } else if (!m_activateIdentifier.isEmpty()) {
         QMap<QString, QUrl> links =
-            m_helpEngine->linksForIdentifier(m_activateIdentifier);
-        if (links.count())
+            helpEngine.linksForIdentifier(m_activateIdentifier);
+        if (!links.isEmpty())
             CentralWidget::instance()->setSource(links.constBegin().value());
     } else if (!m_currentFilter.isEmpty()) {
-        m_helpEngine->setCurrentFilter(m_currentFilter);
+        helpEngine.setCurrentFilter(m_currentFilter);
     }
 
     if (m_syncContents)
diff --git a/tools/assistant/tools/assistant/remotecontrol.h b/tools/assistant/tools/assistant/remotecontrol.h
index 6f7eb5f..5d74996 100644
--- a/tools/assistant/tools/assistant/remotecontrol.h
+++ b/tools/assistant/tools/assistant/remotecontrol.h
@@ -48,17 +48,15 @@
 
 QT_BEGIN_NAMESPACE
 
+class HelpEngineWrapper;
 class MainWindow;
-class QFileSystemWatcher;
-class QHelpEngine;
 
 class RemoteControl : public QObject
 {
     Q_OBJECT
 
 public:
-    RemoteControl(MainWindow *mainWindow, QHelpEngine *helpEngine,
-                  QFileSystemWatcher *qchWatcher);
+    RemoteControl(MainWindow *mainWindow);
 
 private slots:
     void receivedData();
@@ -81,7 +79,6 @@ private:
 
 private:
     MainWindow *m_mainWindow;
-    QHelpEngine *m_helpEngine;
     bool m_debug;
 
     bool m_caching;
@@ -91,7 +88,7 @@ private:
     QString m_activateIdentifier;
     int m_expandTOC;
     QString m_currentFilter;
-    QFileSystemWatcher * const m_qchWatcher;
+    HelpEngineWrapper &helpEngine;
 };
 
 QT_END_NAMESPACE
diff --git a/tools/assistant/tools/assistant/tracer.h b/tools/assistant/tools/assistant/tracer.h
index 913c961..3d8b647 100644
--- a/tools/assistant/tools/assistant/tracer.h
+++ b/tools/assistant/tools/assistant/tracer.h
@@ -65,6 +65,7 @@ private:
 
 QT_END_NAMESPACE
 
+// #define TRACING_REQUESTED
 #ifdef TRACING_REQUESTED
 #define TRACE_OBJ Tracer traceObj__(Q_FUNC_INFO);
 #else
diff --git a/tools/assistant/tools/qcollectiongenerator/main.cpp b/tools/assistant/tools/qcollectiongenerator/main.cpp
index 2eb2b96..467ee88 100644
--- a/tools/assistant/tools/qcollectiongenerator/main.cpp
+++ b/tools/assistant/tools/qcollectiongenerator/main.cpp
@@ -467,8 +467,7 @@ int main(int argc, char *argv[])
     }
 
     if (!config.currentFilter().isEmpty()) {
-        CollectionConfiguration::setCurrentFilter(helpEngine,
-            config.currentFilter());
+        helpEngine.setCurrentFilter(config.currentFilter());
     }
 
     if (!config.cacheDirectory().isEmpty()) {
diff --git a/tools/assistant/tools/shared/collectionconfiguration.cpp b/tools/assistant/tools/shared/collectionconfiguration.cpp
index d0650e4..ba643c9 100644
--- a/tools/assistant/tools/shared/collectionconfiguration.cpp
+++ b/tools/assistant/tools/shared/collectionconfiguration.cpp
@@ -46,30 +46,21 @@
 QT_BEGIN_NAMESPACE
 
 namespace {
-    const QString ListSeparator(QLatin1String("|"));
-
     const QString AboutIconKey(QLatin1String("AboutIcon"));
     const QString AboutImagesKey(QLatin1String("AboutImages"));
     const QString AboutMenuTextsKey(QLatin1String("AboutMenuTexts"));
     const QString AboutTextsKey(QLatin1String("AboutTexts"));
-    const QString AppFontKey(QLatin1String("appFont"));
     const QString ApplicationIconKey(QLatin1String("ApplicationIcon"));
-    const QString AppWritingSystemKey(QLatin1String("appWritingSystem"));
-    const QString BookmarksKey(QLatin1String("Bookmarks"));
-    const QString BrowserFontKey(QLatin1String("browserFont"));
-    const QString BrowserWritingSystemKey(QLatin1String("browserWritingSystem"));
     const QString CacheDirKey(QLatin1String("CacheDirectory"));
     const QString CacheDirRelativeToCollectionKey(QLatin1String("CacheDirRelativeToCollection"));
     const QString CreationTimeKey(QLatin1String("CreationTime"));
-    const QString CurrentFilterKey(QLatin1String("CurrentFilter"));
     const QString DefaultHomePageKey(QLatin1String("defaultHomepage"));
     const QString DocUpdatePendingKey(QLatin1String("DocUpdate"));
     const QString EnableAddressBarKey(QLatin1String("EnableAddressBar"));
     const QString EnableDocManagerKey(QLatin1String("EnableDocumentationManager"));
     const QString EnableFilterKey(QLatin1String("EnableFilterFunctionality"));
-    const QString FilterToolbarHiddenKey(QLatin1String("HideFilterFunctionality"));
     const QString HideAddressBarKey(QLatin1String("HideAddressBar"));
-    const QString HomePageKey(QLatin1String("homepage"));
+    const QString FilterToolbarHiddenKey(QLatin1String("HideFilterFunctionality"));
     const QString LastPageKey(QLatin1String("LastTabPage"));
     const QString LastShownPagesKey(QLatin1String("LastShownPages"));
     const QString LastZoomFactorsKey(QLatin1String(
@@ -79,19 +70,11 @@ namespace {
             "LastPagesZoomTextBrowser"
 #endif
             ));
-    const QString MainWindowKey(QLatin1String("MainWindow"));
-    const QString MainWindowGeometryKey(QLatin1String("MainWindowGeometry"));
-    const QString SearchWasAttachedKey(QLatin1String("SearchWasAttached"));
-    const QString StartOptionKey(QLatin1String("StartOption"));
-    const QString UnfilteredInsertedKey(QLatin1String("UnfilteredFilterInserted"));
-    const QString UseAppFontKey(QLatin1String("useAppFont"));
-    const QString UseBrowserFontKey(QLatin1String("useBrowserFont"));
-    const QString VersionKey(QString(QLatin1String("qtVersion%1$$$%2")).
-                      arg(QLatin1String(QT_VERSION_STR)));
     const QString WindowTitleKey(QLatin1String("WindowTitle"));
 } // anonymous namespace
 
 const QString CollectionConfiguration::DefaultZoomFactor(QLatin1String("0.0"));
+const QString CollectionConfiguration::ListSeparator(QLatin1String("|"));
 
 uint CollectionConfiguration::creationTime(const QHelpEngineCore &helpEngine)
 {
@@ -109,84 +92,18 @@ const QString CollectionConfiguration::windowTitle(const QHelpEngineCore &helpEn
 }
 
 void CollectionConfiguration::setWindowTitle(QHelpEngineCore &helpEngine,
-                                       const QString &windowTitle)
+                                             const QString &windowTitle)
 {
     helpEngine.setCustomValue(WindowTitleKey, windowTitle);
 }
 
-
-int CollectionConfiguration::lastTabPage(const QHelpEngineCore &helpEngine)
-{
-    return helpEngine.customValue(LastPageKey, 1).toInt();
-}
-
-void CollectionConfiguration::setLastTabPage(QHelpEngineCore &helpEngine, int lastPage)
-{
-    helpEngine.setCustomValue(LastPageKey, lastPage);
-}
-
-
-const QStringList CollectionConfiguration::lastShownPages(const QHelpEngineCore &helpEngine)
-{
-    return helpEngine.customValue(LastShownPagesKey).toString().
-        split(ListSeparator, QString::SkipEmptyParts);
-}
-
-void CollectionConfiguration::setLastShownPages(QHelpEngineCore &helpEngine,
-                                          const QStringList &lastShownPages)
-{
-    helpEngine.
-        setCustomValue(LastShownPagesKey, lastShownPages.join(ListSeparator));
-}
-
-const QStringList CollectionConfiguration::lastZoomFactors(const QHelpEngineCore &helpEngine)
-{
-    return helpEngine.customValue(LastZoomFactorsKey).toString().
-        split(ListSeparator, QString::SkipEmptyParts);
-}
-
-void CollectionConfiguration::setLastZoomFactors(QHelpEngineCore &helpEngine,
-                                           const QStringList &lastZoomFactors)
-{
-    helpEngine.setCustomValue(LastZoomFactorsKey, lastZoomFactors.join(ListSeparator));
-}
-
-const QString CollectionConfiguration::currentFilter(const QHelpEngineCore &helpEngine)
-{
-    return helpEngine.customValue(CurrentFilterKey).toString();
-}
-
-void CollectionConfiguration::setCurrentFilter(QHelpEngineCore &helpEngine,
-                                         const QString &currentFilter)
-{
-    helpEngine.setCustomValue(CurrentFilterKey, currentFilter);
-}
-
-const QString CollectionConfiguration::cacheDir(const QHelpEngineCore &helpEngine)
-{
-    return helpEngine.customValue(CacheDirKey).toString();
-}
-
-bool CollectionConfiguration::cacheDirIsRelativeToCollection(const QHelpEngineCore &helpEngine)
-{
-    return helpEngine.customValue(CacheDirRelativeToCollectionKey).toBool();
-}
-
-void CollectionConfiguration::setCacheDir(QHelpEngineCore &helpEngine,
-                            const QString &cacheDir, bool relativeToCollection)
-{
-    helpEngine.setCustomValue(CacheDirKey, cacheDir);
-    helpEngine.setCustomValue(CacheDirRelativeToCollectionKey,
-                              relativeToCollection);
-}
-
 bool CollectionConfiguration::filterFunctionalityEnabled(const QHelpEngineCore &helpEngine)
 {
     return helpEngine.customValue(EnableFilterKey, true).toBool();
 }
 
 void CollectionConfiguration::setFilterFunctionalityEnabled(QHelpEngineCore &helpEngine,
-                                                      bool enabled)
+                                                            bool enabled)
 {
     helpEngine.setCustomValue(EnableFilterKey, enabled);
 }
@@ -197,7 +114,7 @@ bool CollectionConfiguration::filterToolbarVisible(const QHelpEngineCore &helpEn
 }
 
 void CollectionConfiguration::setFilterToolbarVisible(QHelpEngineCore &helpEngine,
-                                                bool visible)
+                                                      bool visible)
 {
     helpEngine.setCustomValue(FilterToolbarHiddenKey, !visible);
 }
@@ -224,6 +141,24 @@ void CollectionConfiguration::setAddressBarVisible(QHelpEngineCore &helpEngine,
     helpEngine.setCustomValue(HideAddressBarKey, !visible);
 }
 
+const QString CollectionConfiguration::cacheDir(const QHelpEngineCore &helpEngine)
+{
+    return helpEngine.customValue(CacheDirKey).toString();
+}
+
+bool CollectionConfiguration::cacheDirIsRelativeToCollection(const QHelpEngineCore &helpEngine)
+{
+    return helpEngine.customValue(CacheDirRelativeToCollectionKey).toBool();
+}
+
+void CollectionConfiguration::setCacheDir(QHelpEngineCore &helpEngine,
+                            const QString &cacheDir, bool relativeToCollection)
+{
+    helpEngine.setCustomValue(CacheDirKey, cacheDir);
+    helpEngine.setCustomValue(CacheDirRelativeToCollectionKey,
+                              relativeToCollection);
+}
+
 bool CollectionConfiguration::documentationManagerEnabled(const QHelpEngineCore &helpEngine)
 {
     return helpEngine.customValue(EnableDocManagerKey, true).toBool();
@@ -302,30 +237,6 @@ void CollectionConfiguration::setDefaultHomePage(QHelpEngineCore &helpEngine,
     helpEngine.setCustomValue(DefaultHomePageKey, page);
 }
 
-const QString CollectionConfiguration::homePage(const QHelpEngineCore &helpEngine)
-{
-    return helpEngine.customValue(HomePageKey).toString();
-}
-
-void CollectionConfiguration::setHomePage(QHelpEngineCore &helpEngine,
-                                          const QString &page)
-{
-    helpEngine.setCustomValue(HomePageKey, page);
-}
-
-int CollectionConfiguration::startOption(const QHelpEngineCore &helpEngine)
-{
-    // TODO: After moving to helpengine wrapper, put LastPages in that header file
-    //       and use it here as default value.
-    return helpEngine.customValue(StartOptionKey).toInt();
-}
-
-void CollectionConfiguration::setStartOption(QHelpEngineCore &helpEngine,
-                                             int option)
-{
-    helpEngine.setCustomValue(StartOptionKey, option);
-}
-
 bool CollectionConfiguration::docUpdatePending(const QHelpEngineCore &helpEngine)
 {
     return helpEngine.customValue(DocUpdatePendingKey, false).toBool();
@@ -337,145 +248,41 @@ void CollectionConfiguration::setDocUpdatePending(QHelpEngineCore &helpEngine,
     helpEngine.setCustomValue(DocUpdatePendingKey, pending);
 }
 
-const QByteArray CollectionConfiguration::bookmarks(const QHelpEngineCore &helpEngine)
-{
-    return helpEngine.customValue(BookmarksKey).toByteArray();
-}
-
-void CollectionConfiguration::setBookmarks(QHelpEngineCore &helpEngine,
-                                           const QByteArray &bookmarks)
-{
-    helpEngine.setCustomValue(BookmarksKey, bookmarks);
-}
-
-const QByteArray CollectionConfiguration::mainWindow(const QHelpEngineCore &helpEngine)
-{
-    return helpEngine.customValue(MainWindowKey).toByteArray();
-}
-
-void CollectionConfiguration::setMainWindow(QHelpEngineCore &helpEngine,
-                                            const QByteArray &mainWindow)
-{
-    helpEngine.setCustomValue(MainWindowKey, mainWindow);
-}
-
-const QByteArray CollectionConfiguration::mainWindowGeometry(const QHelpEngineCore &helpEngine)
-{
-    return helpEngine.customValue(MainWindowGeometryKey).toByteArray();
-}
-
-void CollectionConfiguration::setMainWindowGeometry(QHelpEngineCore &helpEngine,
-                                                    const QByteArray &geometry)
-{
-    helpEngine.setCustomValue(MainWindowGeometryKey, geometry);
-}
-
-bool CollectionConfiguration::usesAppFont(const QHelpEngineCore &helpEngine)
-{
-    return helpEngine.customValue(UseAppFontKey).toBool();
-}
-
-void CollectionConfiguration::setUseAppFont(QHelpEngineCore &helpEngine,
-                                            bool useAppFont)
-{
-    helpEngine.setCustomValue(UseAppFontKey, useAppFont);
-}
-
-bool CollectionConfiguration::usesBrowserFont(const QHelpEngineCore &helpEngine)
-{
-    return helpEngine.customValue(UseBrowserFontKey, false).toBool();
-}
-
-void CollectionConfiguration::setUseBrowserFont(QHelpEngineCore &helpEngine,
-                                                bool useBrowserFont)
-{
-    helpEngine.setCustomValue(UseBrowserFontKey, useBrowserFont);
-}
-
-const QFont CollectionConfiguration::appFont(const QHelpEngineCore &helpEngine)
-{
-    return qVariantValue<QFont>(helpEngine.customValue(AppFontKey));
-}
-
-void CollectionConfiguration::setAppFont(QHelpEngineCore &helpEngine,
-                                         const QFont &font)
-{
-    helpEngine.setCustomValue(AppFontKey, font);
-}
-
-QFontDatabase::WritingSystem CollectionConfiguration::appWritingSystem(const QHelpEngineCore &helpEngine)
-{
-    return static_cast<QFontDatabase::WritingSystem>(
-        helpEngine.customValue(AppWritingSystemKey).toInt());
-}
-
-void CollectionConfiguration::setAppWritingSystem(QHelpEngineCore &helpEngine,
-                                            QFontDatabase::WritingSystem system)
-{
-    helpEngine.setCustomValue(AppWritingSystemKey, system);
-}
-
-const QFont CollectionConfiguration::browserFont(const QHelpEngineCore &helpEngine)
-{
-    return qVariantValue<QFont>(helpEngine.customValue(BrowserFontKey));
-}
-
-void CollectionConfiguration::setBrowserFont(QHelpEngineCore &helpEngine,
-                                             const QFont &font)
-{
-    helpEngine.setCustomValue(BrowserFontKey, font);
-}
-
-QFontDatabase::WritingSystem CollectionConfiguration::browserWritingSystem(const QHelpEngineCore &helpEngine)
-{
-    return static_cast<QFontDatabase::WritingSystem>(
-        helpEngine.customValue(BrowserWritingSystemKey).toInt());
-}
-
-void CollectionConfiguration::setBrowserWritingSystem(QHelpEngineCore &helpEngine,
-                                            QFontDatabase::WritingSystem system)
-{
-    helpEngine.setCustomValue(BrowserWritingSystemKey, system);
-}
-
-bool CollectionConfiguration::unfilteredInserted(const QHelpEngineCore &helpEngine)
-{
-    return helpEngine.customValue(UnfilteredInsertedKey).toInt() == 1;
-}
-
-void CollectionConfiguration::setUnfilteredInserted(QHelpEngineCore &helpEngine)
+const QStringList CollectionConfiguration::lastShownPages(const QHelpEngineCore &helpEngine)
 {
-    helpEngine.setCustomValue(UnfilteredInsertedKey, 1);
+    return helpEngine.customValue(LastShownPagesKey).toString().
+        split(ListSeparator, QString::SkipEmptyParts);
 }
 
-const QStringList CollectionConfiguration::qtDocInfo(const QHelpEngineCore &helpEngine,
-                                                     const QString &component)
+void CollectionConfiguration::setLastShownPages(QHelpEngineCore &helpEngine,
+                                             const QStringList &lastShownPages)
 {
-    return helpEngine.customValue(VersionKey.arg(component)).toString().
-        split(ListSeparator);
+    helpEngine.setCustomValue(LastShownPagesKey,
+                              lastShownPages.join(ListSeparator));
 }
 
-void CollectionConfiguration::setQtDocInfo(QHelpEngineCore &helpEngine,
-                               const QString &component, const QStringList &doc)
+const QStringList CollectionConfiguration::lastZoomFactors(const QHelpEngineCore &helpEngine)
 {
-    helpEngine.setCustomValue(VersionKey.arg(component),
-                              doc.join(ListSeparator));
+    return helpEngine.customValue(LastZoomFactorsKey).toString().
+        split(ListSeparator, QString::SkipEmptyParts);
 }
 
-bool CollectionConfiguration::searchWasAttached(const QHelpEngineCore &helpEngine)
+void CollectionConfiguration::setLastZoomFactors(QHelpEngineCore &helpEngine,
+                                             const QStringList &lastZoomFactors)
 {
-    return helpEngine.customValue(SearchWasAttachedKey).toBool();
+    helpEngine.setCustomValue(LastZoomFactorsKey,
+                              lastZoomFactors.join(ListSeparator));
 }
 
-void CollectionConfiguration::setSearchWasAttached(QHelpEngineCore &helpEngine,
-                                                   bool attached)
+int CollectionConfiguration::lastTabPage(const QHelpEngineCore &helpEngine)
 {
-    helpEngine.setCustomValue(SearchWasAttachedKey, attached);
+    return helpEngine.customValue(LastPageKey, 1).toInt();
 }
 
-bool CollectionConfiguration::hasFontSettings(const QHelpEngineCore &helpEngine)
+void CollectionConfiguration::setLastTabPage(QHelpEngineCore &helpEngine,
+                                             int lastPage)
 {
-    return helpEngine.customValue(UseAppFontKey).isValid();
+    helpEngine.setCustomValue(LastPageKey, lastPage);
 }
 
 bool CollectionConfiguration::isNewer(const QHelpEngineCore &newer,
@@ -489,9 +296,7 @@ void CollectionConfiguration::copyConfiguration(const QHelpEngineCore &source,
 {
     setCreationTime(target, creationTime(source));
     setWindowTitle(target, windowTitle(source));
-    setLastShownPages(target, lastShownPages(source));
-    setLastZoomFactors(target, lastZoomFactors(source));
-    setCurrentFilter(target, currentFilter(source));
+    target.setCurrentFilter(source.currentFilter());
     setCacheDir(target, cacheDir(source), cacheDirIsRelativeToCollection(source));
     setFilterFunctionalityEnabled(target, filterFunctionalityEnabled(source));
     setFilterToolbarVisible(target, filterToolbarVisible(source));
diff --git a/tools/assistant/tools/shared/collectionconfiguration.h b/tools/assistant/tools/shared/collectionconfiguration.h
index 48d2803..4e77abe 100644
--- a/tools/assistant/tools/shared/collectionconfiguration.h
+++ b/tools/assistant/tools/shared/collectionconfiguration.h
@@ -46,8 +46,6 @@
 #include <QtCore/QCoreApplication>
 #include <QtCore/QString>
 #include <QtCore/QStringList>
-#include <QtGui/QFont>
-#include <QtGui/QFontDatabase>
 
 QT_BEGIN_NAMESPACE
 
@@ -56,29 +54,18 @@ class QHelpEngineCore;
 class CollectionConfiguration
 {
 public:
-    static int lastTabPage(const QHelpEngineCore &helpEngine);
-    static void setLastTabPage(QHelpEngineCore &helpEngine, int lastPage);
-
-    static const QStringList lastShownPages(const QHelpEngineCore &helpEngine);
-    static void setLastShownPages(QHelpEngineCore &helpEngine,
-                                  const QStringList &lastShownPages);
-
-
-    // TODO: Don't allow last pages and zoom factors to be set in isolation
-    //       Perhaps also fill up missing elements automatically or assert.
-    static const QStringList lastZoomFactors(const QHelpEngineCore &helpEngine);
-    static void setLastZoomFactors(QHelpEngineCore &helpEngine,
-                                   const QStringList &lastZoomFactors);
-
-    static const QString currentFilter(const QHelpEngineCore &helpEngine);
-    static void setCurrentFilter(QHelpEngineCore &helpEngine,
-                                 const QString &currentFilter);
+    static const QString windowTitle(const QHelpEngineCore &helpEngine);
+    static void setWindowTitle(QHelpEngineCore &helpEngine,
+                               const QString &windowTitle);
 
     static const QString cacheDir(const QHelpEngineCore &helpEngine);
     static bool cacheDirIsRelativeToCollection(const QHelpEngineCore &helpEngine);
     static void setCacheDir(QHelpEngineCore &helpEngine,
                             const QString &cacheDir, bool relativeToCollection);
 
+    static uint creationTime(const QHelpEngineCore &helpEngine);
+    static void setCreationTime(QHelpEngineCore &helpEngine, uint time);
+
     static bool filterFunctionalityEnabled(const QHelpEngineCore &helpEngine);
     static void setFilterFunctionalityEnabled(QHelpEngineCore &helpEngine,
                                               bool enabled);
@@ -93,12 +80,6 @@ public:
     static bool addressBarVisible(const QHelpEngineCore &helpEngine);
     static void setAddressBarVisible(QHelpEngineCore &helpEngine, bool visible);
 
-    static uint creationTime(const QHelpEngineCore &helpEngine);
-    static void setCreationTime(QHelpEngineCore &helpEngine, uint time);
-
-    static const QString windowTitle(const QHelpEngineCore &helpEngine);
-    static void setWindowTitle(QHelpEngineCore &helpEngine,
-                               const QString &windowTitle);
 
     static bool documentationManagerEnabled(const QHelpEngineCore &helpEngine);
     static void setDocumentationManagerEnabled(QHelpEngineCore &helpEngine,
@@ -108,12 +89,6 @@ public:
     static void setApplicationIcon(QHelpEngineCore &helpEngine,
                                    const QByteArray &icon);
 
-    static const QString homePage(const QHelpEngineCore &helpEngine);
-    static void setHomePage(QHelpEngineCore &helpEngine, const QString &page);
-
-    static int startOption(const QHelpEngineCore &helpEngine);
-    static void setStartOption(QHelpEngineCore &helpEngine, int option);
-
     // TODO: Encapsulate encoding from/to QByteArray here
     static const QByteArray aboutMenuTexts(const QHelpEngineCore &helpEngine);
     static void setAboutMenuTexts(QHelpEngineCore &helpEngine,
@@ -139,58 +114,25 @@ public:
     static bool docUpdatePending(const QHelpEngineCore &helpEngine);
     static void setDocUpdatePending(QHelpEngineCore &helpEngine, bool pending);
 
-    // TODO: Put these GUI-specific functions in the help engine wrapper
-    static const QByteArray bookmarks(const QHelpEngineCore &helpEngine);
-    static void setBookmarks(QHelpEngineCore &helpEngine,
-                             const QByteArray &bookmarks);
-
-    static const QByteArray mainWindow(const QHelpEngineCore &helpEngine);
-    static void setMainWindow(QHelpEngineCore &helpEngine,
-                              const QByteArray &mainWindow);
-
-    static const QByteArray mainWindowGeometry(const QHelpEngineCore &helpEngine);
-    static void setMainWindowGeometry(QHelpEngineCore &helpEngine,
-                                      const QByteArray &geometry);
-
-    static bool usesAppFont(const QHelpEngineCore &helpEngine);
-    static void setUseAppFont(QHelpEngineCore &helpEngine, bool useAppFont);
-
-    static bool usesBrowserFont(const QHelpEngineCore &helpEngine);
-    static void setUseBrowserFont(QHelpEngineCore &helpEngine,
-                                  bool useBrowserFont);
-
-    static const QFont appFont(const QHelpEngineCore &helpEngine);
-    static void setAppFont(QHelpEngineCore &helpEngine, const QFont &font);
-
-    static QFontDatabase::WritingSystem appWritingSystem(const QHelpEngineCore &helpEngine);
-    static void setAppWritingSystem(QHelpEngineCore &helpEngine,
-                                    QFontDatabase::WritingSystem system);
-
-    static const QFont browserFont(const QHelpEngineCore &helpEngine);
-    static void setBrowserFont(QHelpEngineCore &helpEngine, const QFont &font);
-
-    static QFontDatabase::WritingSystem browserWritingSystem(const QHelpEngineCore &helpEngine);
-    static void setBrowserWritingSystem(QHelpEngineCore &helpEngine,
-                                        QFontDatabase::WritingSystem system);
-
-    static bool unfilteredInserted(const QHelpEngineCore &helpEngine);
-    static void setUnfilteredInserted(QHelpEngineCore &helpEngine);
-
-    static const QStringList qtDocInfo(const QHelpEngineCore &helpEngine,
-                                       const QString &component);
-    static void setQtDocInfo(QHelpEngineCore &helpEngine,
-                             const QString &component, const QStringList &doc);
+    // TODO: Don't allow last pages and zoom factors to be set in isolation
+    //       Perhaps also fill up missing elements automatically or assert.
+    static const QStringList lastShownPages(const QHelpEngineCore &helpEngine);
+    static void setLastShownPages(QHelpEngineCore &helpEngine,
+                                  const QStringList &lastShownPages);
+    static const QStringList lastZoomFactors(const QHelpEngineCore &helpEngine);
+    static void setLastZoomFactors(QHelpEngineCore &helPEngine,
+                                   const QStringList &lastZoomFactors);
 
-    static bool searchWasAttached(const QHelpEngineCore &helpEngine);
-    static void setSearchWasAttached(QHelpEngineCore &helpEngine, bool attached);
+    static int lastTabPage(const QHelpEngineCore &helpEngine);
+    static void setLastTabPage(QHelpEngineCore &helpEngine, int lastPage);
 
-    static bool hasFontSettings(const QHelpEngineCore &helpEngine);
     static bool isNewer(const QHelpEngineCore &newer,
                         const QHelpEngineCore &older);
     static void copyConfiguration(const QHelpEngineCore &source,
                                   QHelpEngineCore &target);
 
     static const QString DefaultZoomFactor;
+    static const QString ListSeparator;
 };
 
 QT_END_NAMESPACE