Integrate new filter engine

Adapt the code to deprecated usage of map as a multi map,
hence all cases replaced by QMultiMap.

Change-Id: I2d480467cd6e91d3e880555e6a21058dec056b3f
Reviewed-by: Karsten Heimrich <karsten.heimrich@qt.io>

src/plugins/help/helpmanager.cpp

@@ -43,10 +43,15 @@
 #include <QHelpEngineCore>
 
 #include <QMutexLocker>
+
+#ifndef HELP_NEW_FILTER_ENGINE
 #include <QSqlDatabase>
 #include <QSqlDriver>
 #include <QSqlError>
 #include <QSqlQuery>
+#else
+#include <QtHelp/QHelpLink>
+#endif
 
 using namespace Core;
 
@@ -84,6 +89,8 @@ struct HelpManagerPrivate
 static HelpManager *m_instance = nullptr;
 static HelpManagerPrivate *d = nullptr;
 
+#ifndef HELP_NEW_FILTER_ENGINE
+
 // -- DbCleaner
 
 struct DbCleaner
@@ -93,6 +100,8 @@ struct DbCleaner
     QString name;
 };
 
+#endif
+
 // -- HelpManager
 
 HelpManager::HelpManager(QObject *parent) :
@@ -225,20 +234,36 @@ QSet<QString> HelpManager::userDocumentationPaths()
 }
 
 // This should go into Qt 4.8 once we start using it for Qt Creator
-QMap<QString, QUrl> HelpManager::linksForKeyword(const QString &key)
+QMultiMap<QString, QUrl> HelpManager::linksForKeyword(const QString &key)
 {
     QTC_ASSERT(!d->m_needsSetup, return {});
     if (key.isEmpty())
         return {};
+#ifndef HELP_NEW_FILTER_ENGINE
     return d->m_helpEngine->linksForKeyword(key);
+#else
+    QMultiMap<QString, QUrl> links;
+    const QList<QHelpLink> docs = d->m_helpEngine->documentsForKeyword(key, QString());
+    for (const auto doc : docs)
+        links.insert(doc.title, doc.url);
+    return links;
+#endif
 }
 
-QMap<QString, QUrl> HelpManager::linksForIdentifier(const QString &id)
+QMultiMap<QString, QUrl> HelpManager::linksForIdentifier(const QString &id)
 {
     QTC_ASSERT(!d->m_needsSetup, return {});
     if (id.isEmpty())
         return {};
+#ifndef HELP_NEW_FILTER_ENGINE
     return d->m_helpEngine->linksForIdentifier(id);
+#else
+    QMultiMap<QString, QUrl> links;
+    const QList<QHelpLink> docs = d->m_helpEngine->documentsForIdentifier(id, QString());
+    for (const auto doc : docs)
+        links.insert(doc.title, doc.url);
+    return links;
+#endif
 }
 
 QUrl HelpManager::findFile(const QUrl &url)
@@ -292,6 +317,8 @@ QVariant HelpManager::customValue(const QString &key, const QVariant &value)
     return d->m_helpEngine->customValue(key, value);
 }
 
+#ifndef HELP_NEW_FILTER_ENGINE
+
 HelpManager::Filters HelpManager::filters()
 {
     QTC_ASSERT(!d->m_needsSetup, return {});
@@ -358,6 +385,8 @@ void HelpManager::addUserDefinedFilter(const QString &filter, const QStringList
         emit m_instance->collectionFileChanged();
 }
 
+#endif
+
 void HelpManager::aboutToShutdown()
 {
     if (d && d->m_registerFuture.isRunning()) {
@@ -378,6 +407,9 @@ void HelpManager::setupHelpManager()
 
     // create the help engine
     d->m_helpEngine = new QHelpEngineCore(collectionFilePath(), m_instance);
+#ifdef HELP_NEW_FILTER_ENGINE
+    d->m_helpEngine->setUsesFilterEngine(true);
+#endif
     d->m_helpEngine->setupData();
 
     for (const QString &filePath : d->documentationFromInstaller())