Help: Remove code paths supporting old filter engine < Qt 5.15

Change-Id: Ie3008ac78294f8831c22e73aa325e1da3b4016f2
Reviewed-by: Jarek Kobus <[email protected]>

16 files changed, 3 insertions, 819 deletions

diff --git a/src/plugins/help/CMakeLists.txt b/src/plugins/help/CMakeLists.txt
index 09050db7b96..b9f6a26de51 100644
--- a/src/plugins/help/CMakeLists.txt
+++ b/src/plugins/help/CMakeLists.txt
@@ -5,7 +5,7 @@ add_qtc_plugin(Help
   PLUGIN_RECOMMENDS TextEditor
   SOURCES
     docsettingspage.cpp docsettingspage.h docsettingspage.ui
-    filtersettingspage.cpp filtersettingspage.h filtersettingspage.ui
+    filtersettingspage.cpp filtersettingspage.h
     generalsettingspage.cpp generalsettingspage.h generalsettingspage.ui
     help.qrc
     helpconstants.h
@@ -26,11 +26,6 @@ add_qtc_plugin(Help
     xbelsupport.cpp xbelsupport.h
 )
 
-extend_qtc_plugin(Help
-  CONDITION Qt5_VERSION VERSION_GREATER_EQUAL 5.15.0
-  DEFINES HELP_NEW_FILTER_ENGINE
-)
-
 set(HELPVIEWER_DEFAULT_BACKEND "litehtml" CACHE STRING "Sets default help viewer backend")
 set_property(CACHE HELPVIEWER_DEFAULT_BACKEND PROPERTY STRINGS "litehtml;qtwebengine;textbrowser")
 
diff --git a/src/plugins/help/filtersettingspage.cpp b/src/plugins/help/filtersettingspage.cpp
index 805ab844ed6..ea4cfb037d7 100644
--- a/src/plugins/help/filtersettingspage.cpp
+++ b/src/plugins/help/filtersettingspage.cpp
@@ -26,29 +26,11 @@
 #include "filtersettingspage.h"
 #include "helpconstants.h"
 
-#ifndef HELP_NEW_FILTER_ENGINE
-
-#include "helpmanager.h"
-
-#include <filternamedialog.h>
-
-#include <coreplugin/helpmanager.h>
-
-#include <utils/algorithm.h>
-
-#include <QCoreApplication>
-#include <QFileDialog>
-#include <QMessageBox>
-
-#else
-
 #include <QtCore/QVersionNumber>
 #include <QtHelp/QHelpFilterEngine>
 #include <QtHelp/QHelpFilterSettingsWidget>
 #include "localhelpmanager.h"
 
-#endif
-
 using namespace Help::Internal;
 
 FilterSettingsPage::FilterSettingsPage()
@@ -58,218 +40,6 @@ FilterSettingsPage::FilterSettingsPage()
     setCategory(Help::Constants::HELP_CATEGORY);
 }
 
-#ifndef HELP_NEW_FILTER_ENGINE
-
-QWidget *FilterSettingsPage::widget()
-{
-    if (!m_widget) {
-        m_widget = new QWidget;
-        m_ui.setupUi(m_widget);
-
-        updateFilterPage();
-
-        connect(m_ui.attributeWidget, &QTreeWidget::itemChanged,
-                this, &FilterSettingsPage::updateFilterMap);
-        connect(m_ui.filterWidget, &QListWidget::currentItemChanged,
-                this, &FilterSettingsPage::updateAttributes);
-        connect(m_ui.filterAddButton, &QPushButton::clicked,
-                this, &FilterSettingsPage::addFilter);
-        connect(m_ui.filterRemoveButton, &QPushButton::clicked,
-                this, &FilterSettingsPage::removeFilter);
-        connect(Core::HelpManager::Signals::instance(),
-                &Core::HelpManager::Signals::documentationChanged,
-                this,
-                &FilterSettingsPage::updateFilterPage);
-    }
-    return m_widget;
-}
-
-void FilterSettingsPage::updateFilterPage()
-{
-    m_ui.filterWidget->clear();
-    m_ui.attributeWidget->clear();
-
-    m_filterMapBackup.clear();
-
-    QString lastTrUnfiltered;
-    const QString trUnfiltered = tr("Unfiltered");
-    if (HelpManager::customValue(Help::Constants::WeAddedFilterKey).toInt() == 1) {
-        lastTrUnfiltered =
-            HelpManager::customValue(Help::Constants::PreviousFilterNameKey).toString();
-    }
-
-    HelpManager::Filters filters = HelpManager::userDefinedFilters();
-    HelpManager::Filters::const_iterator it;
-    for (it = filters.constBegin(); it != filters.constEnd(); ++it) {
-        const QString &filter = it.key();
-        if (filter == trUnfiltered || filter == lastTrUnfiltered)
-            continue;
-
-        m_filterMapBackup.insert(filter, it.value());
-        if (!m_filterMap.contains(filter))
-            m_filterMap.insert(filter, it.value());
-    }
-    m_ui.filterWidget->addItems(m_filterMap.keys());
-
-    QSet<QString> attributes;
-    filters = HelpManager::filters();
-    for (it = filters.constBegin(); it != filters.constEnd(); ++it)
-        attributes += Utils::toSet(it.value());
-
-    foreach (const QString &attribute, attributes)
-        new QTreeWidgetItem(m_ui.attributeWidget, QStringList(attribute));
-
-    if (!m_filterMap.isEmpty()) {
-        m_ui.filterWidget->setCurrentRow(0);
-        updateAttributes(m_ui.filterWidget->currentItem());
-    }
-}
-
-void FilterSettingsPage::updateAttributes(QListWidgetItem *item)
-{
-    QStringList checkedList;
-    if (item)
-        checkedList = m_filterMap.value(item->text());
-
-    for (int i = 0; i < m_ui.attributeWidget->topLevelItemCount(); ++i) {
-        QTreeWidgetItem *itm = m_ui.attributeWidget->topLevelItem(i);
-        if (checkedList.contains(itm->text(0)))
-            itm->setCheckState(0, Qt::Checked);
-        else
-            itm->setCheckState(0, Qt::Unchecked);
-    }
-
-    updateFilterDescription(item ? item->text() : QString());
-}
-
-void FilterSettingsPage::updateFilterMap()
-{
-    if (!m_ui.filterWidget->currentItem())
-        return;
-
-    const QString &filter = m_ui.filterWidget->currentItem()->text();
-    if (!m_filterMap.contains(filter))
-        return;
-
-    QStringList newAtts;
-    for (int i = 0; i < m_ui.attributeWidget->topLevelItemCount(); ++i) {
-        QTreeWidgetItem *itm = m_ui.attributeWidget->topLevelItem(i);
-        if (itm->checkState(0) == Qt::Checked)
-            newAtts.append(itm->text(0));
-    }
-    m_filterMap[filter] = newAtts;
-    updateFilterDescription(filter);
-}
-
-void FilterSettingsPage::addFilter()
-{
-    FilterNameDialog dia(m_ui.filterWidget);
-    if (dia.exec() == QDialog::Rejected)
-        return;
-
-    const QString &filterName = dia.filterName();
-    if (!m_filterMap.contains(filterName)) {
-        m_filterMap.insert(filterName, QStringList());
-        m_ui.filterWidget->addItem(filterName);
-    }
-
-    const QList<QListWidgetItem*> &lst = m_ui.filterWidget->findItems(filterName,
-        Qt::MatchCaseSensitive);
-    m_ui.filterWidget->setCurrentItem(lst.first());
-}
-
-void FilterSettingsPage::removeFilter()
-{
-    QListWidgetItem *item =
-        m_ui.filterWidget->takeItem(m_ui.filterWidget->currentRow());
-    if (!item)
-        return;
-
-    m_filterMap.remove(item->text());
-    m_removedFilters.append(item->text());
-    delete item;
-    if (m_ui.filterWidget->count())
-        m_ui.filterWidget->setCurrentRow(0);
-
-    item = m_ui.filterWidget->item(m_ui.filterWidget->currentRow());
-    updateFilterDescription(item ? item->text() : QString());
-}
-
-void FilterSettingsPage::apply()
-{
-    bool changed = m_filterMap.count() != m_filterMapBackup.count();
-    if (!changed) {
-        FilterMap::const_iterator it = m_filterMapBackup.constBegin();
-        for (; it != m_filterMapBackup.constEnd() && !changed; ++it) {
-            if (m_filterMap.contains(it.key())) {
-                const QStringList &a = it.value();
-                const QStringList &b = m_filterMap.value(it.key());
-                if (a.count() == b.count()) {
-                    QStringList::const_iterator i = a.constBegin();
-                    for (; i != a.constEnd() && !changed; ++i) {
-                        if (b.contains(*i))
-                            continue;
-                        changed = true;
-                    }
-                } else {
-                    changed = true;
-                }
-            } else {
-                changed = true;
-            }
-        }
-    }
-
-    if (changed) {
-        foreach (const QString &filter, m_removedFilters)
-            HelpManager::removeUserDefinedFilter(filter);
-
-        FilterMap::const_iterator it;
-        for (it = m_filterMap.constBegin(); it != m_filterMap.constEnd(); ++it)
-            HelpManager::addUserDefinedFilter(it.key(), it.value());
-
-        // emit this signal to the help plugin, since we don't want
-        // to force gui help engine setup if we are not in help mode
-        emit filtersChanged();
-    }
-}
-
-void FilterSettingsPage::finish()
-{
-    disconnect(Core::HelpManager::Signals::instance(),
-               &Core::HelpManager::Signals::documentationChanged,
-               this,
-               &FilterSettingsPage::updateFilterPage);
-    delete m_widget;
-}
-
-QString FilterSettingsPage::msgFilterLabel(const QString &filter) const
-{
-    if (m_filterMap.isEmpty())
-        return tr("No user defined filters available or no filter selected.");
-
-    const QStringList &checkedList = m_filterMap.value(filter);
-    if (checkedList.isEmpty())
-        return tr("The filter \"%1\" will show every documentation file"
-                  " available, as no attributes are specified.").arg(filter);
-
-    if (checkedList.size() == 1)
-        return tr("The filter \"%1\" will only show documentation files that"
-                  " have the attribute %2 specified.").
-                arg(filter, checkedList.first());
-
-    return tr("The filter \"%1\" will only show documentation files that"
-              " have the attributes %2 specified.").
-            arg(filter, checkedList.join(", "));
-}
-
-void FilterSettingsPage::updateFilterDescription(const QString &filter)
-{
-    m_ui.label->setText(msgFilterLabel(filter));
-}
-
-#else
-
 QWidget *FilterSettingsPage::widget()
 {
     if (!m_widget) {
@@ -310,5 +80,3 @@ void FilterSettingsPage::updateFilterPage()
     m_widget->setAvailableVersions(LocalHelpManager::filterEngine()->availableVersions());
 }
 
-#endif
-
diff --git a/src/plugins/help/filtersettingspage.h b/src/plugins/help/filtersettingspage.h
index 469df0d23d2..209919df9c1 100644
--- a/src/plugins/help/filtersettingspage.h
+++ b/src/plugins/help/filtersettingspage.h
@@ -29,13 +29,9 @@
 
 #include <QPointer>
 
-#ifndef HELP_NEW_FILTER_ENGINE
-#include "ui_filtersettingspage.h"
-#else
 QT_BEGIN_NAMESPACE
 class QHelpFilterSettingsWidget;
 QT_END_NAMESPACE
-#endif
 
 namespace Help {
 namespace Internal {
@@ -57,25 +53,7 @@ signals:
 private:
 
     void updateFilterPage();
-#ifndef HELP_NEW_FILTER_ENGINE
-    void updateAttributes(QListWidgetItem *item);
-    void updateFilterMap();
-    void addFilter();
-    void removeFilter();
-    void updateFilterDescription(const QString &filter);
-    QString msgFilterLabel(const QString &filter) const;
-
-    Ui::FilterSettingsPage m_ui;
-    QPointer<QWidget> m_widget;
-
-    using FilterMap = QMap<QString, QStringList>;
-    FilterMap m_filterMap;
-    FilterMap m_filterMapBackup;
-
-    QStringList m_removedFilters;
-#else
     QPointer<QHelpFilterSettingsWidget> m_widget;
-#endif
 
 };
 
diff --git a/src/plugins/help/filtersettingspage.ui b/src/plugins/help/filtersettingspage.ui
deleted file mode 100644
index 62eb2989eab..00000000000
--- a/src/plugins/help/filtersettingspage.ui
+++ /dev/null
@@ -1,148 +0,0 @@
-<?xml version="1.0" encoding="UTF-8"?>
-<ui version="4.0">
- <class>Help::Internal::FilterSettingsPage</class>
- <widget class="QWidget" name="Help::Internal::FilterSettingsPage">
-  <property name="geometry">
-   <rect>
-    <x>0</x>
-    <y>0</y>
-    <width>419</width>
-    <height>313</height>
-   </rect>
-  </property>
-  <property name="toolTip">
-   <string>&lt;html&gt;&lt;body&gt;
-&lt;p&gt;
-Add, modify, and remove document filters, which determine the documentation set displayed in the Help mode. The attributes are defined in the documents. Select them to display a set of relevant documentation. Note that some attributes are defined in several documents.
-&lt;/p&gt;&lt;/body&gt;&lt;/html&gt;</string>
-  </property>
-  <layout class="QVBoxLayout" name="verticalLayout_2">
-   <item>
-    <layout class="QHBoxLayout" name="mainHorizontalLayout">
-     <item>
-      <widget class="QGroupBox" name="filterGroupBox">
-       <property name="title">
-        <string>Filters</string>
-       </property>
-       <layout class="QHBoxLayout" name="horizontalLayout_2">
-        <item>
-         <widget class="QListWidget" name="filterWidget">
-          <property name="sizePolicy">
-           <sizepolicy hsizetype="Expanding" vsizetype="Expanding">
-            <horstretch>10</horstretch>
-            <verstretch>0</verstretch>
-           </sizepolicy>
-          </property>
-          <property name="minimumSize">
-           <size>
-            <width>0</width>
-            <height>150</height>
-           </size>
-          </property>
-          <property name="uniformItemSizes">
-           <bool>true</bool>
-          </property>
-         </widget>
-        </item>
-       </layout>
-      </widget>
-     </item>
-     <item>
-      <widget class="QGroupBox" name="attributesGroupBox">
-       <property name="title">
-        <string>Attributes</string>
-       </property>
-       <layout class="QVBoxLayout" name="verticalLayout">
-        <item>
-         <widget class="QTreeWidget" name="attributeWidget">
-          <property name="sizePolicy">
-           <sizepolicy hsizetype="Expanding" vsizetype="Expanding">
-            <horstretch>0</horstretch>
-            <verstretch>0</verstretch>
-           </sizepolicy>
-          </property>
-          <property name="minimumSize">
-           <size>
-            <width>0</width>
-            <height>150</height>
-           </size>
-          </property>
-          <property name="showDropIndicator" stdset="0">
-           <bool>false</bool>
-          </property>
-          <property name="rootIsDecorated">
-           <bool>false</bool>
-          </property>
-          <property name="uniformRowHeights">
-           <bool>true</bool>
-          </property>
-          <attribute name="headerVisible">
-           <bool>false</bool>
-          </attribute>
-          <column>
-           <property name="text">
-            <string>1</string>
-           </property>
-          </column>
-         </widget>
-        </item>
-       </layout>
-      </widget>
-     </item>
-    </layout>
-   </item>
-   <item>
-    <widget class="QLabel" name="label">
-     <property name="minimumSize">
-      <size>
-       <width>0</width>
-       <height>50</height>
-      </size>
-     </property>
-     <property name="text">
-      <string>No user defined filters available or no filter selected.</string>
-     </property>
-     <property name="alignment">
-      <set>Qt::AlignLeading|Qt::AlignLeft|Qt::AlignTop</set>
-     </property>
-     <property name="wordWrap">
-      <bool>true</bool>
-     </property>
-    </widget>
-   </item>
-   <item>
-    <layout class="QHBoxLayout" name="horizontalLayout">
-     <item>
-      <widget class="QPushButton" name="filterAddButton">
-       <property name="text">
-        <string>Add...</string>
-       </property>
-      </widget>
-     </item>
-     <item>
-      <widget class="QPushButton" name="filterRemoveButton">
-       <property name="text">
-        <string>Remove</string>
-       </property>
-      </widget>
-     </item>
-     <item>
-      <spacer name="buttonHorizontalSpacer">
-       <property name="orientation">
-        <enum>Qt::Horizontal</enum>
-       </property>
-       <property name="sizeHint" stdset="0">
-        <size>
-         <width>40</width>
-         <height>20</height>
-        </size>
-       </property>
-      </spacer>
-     </item>
-    </layout>
-   </item>
-  </layout>
- </widget>
- <resources/>
- <connections/>
-</ui>
diff --git a/src/plugins/help/help.qbs b/src/plugins/help/help.qbs
index a1bfca2de61..b340505230e 100644
--- a/src/plugins/help/help.qbs
+++ b/src/plugins/help/help.qbs
@@ -26,8 +26,6 @@ Project {
                 defines.push("QTC_WEBENGINE_HELPVIEWER");
             if (qlitehtml.present)
                 defines.push("QTC_LITEHTML_HELPVIEWER")
-            if (Utilities.versionCompare(Qt.core.version, "5.15") >= 0)
-                defines.push("HELP_NEW_FILTER_ENGINE");
             return defines;
         }
 
@@ -38,7 +36,7 @@ Project {
             name: "Sources"
             files: [
                 "docsettingspage.cpp", "docsettingspage.h", "docsettingspage.ui",
-                "filtersettingspage.cpp", "filtersettingspage.h", "filtersettingspage.ui",
+                "filtersettingspage.cpp", "filtersettingspage.h",
                 "generalsettingspage.cpp", "generalsettingspage.h", "generalsettingspage.ui",
                 "help.qrc",
                 "helpconstants.h",
diff --git a/src/plugins/help/helpindexfilter.cpp b/src/plugins/help/helpindexfilter.cpp
index 5e422c3a59d..05c55e1c79a 100644
--- a/src/plugins/help/helpindexfilter.cpp
+++ b/src/plugins/help/helpindexfilter.cpp
@@ -36,24 +36,11 @@
 
 #include <QIcon>
 
-#ifndef HELP_NEW_FILTER_ENGINE
-
-#include <utils/algorithm.h>
-
-#include <QSqlDatabase>
-#include <QSqlDriver>
-#include <QSqlError>
-#include <QSqlQuery>
-
-#else
-
 #include "localhelpmanager.h"
 #include <QtHelp/QHelpEngine>
 #include <QtHelp/QHelpFilterEngine>
 #include <QtHelp/QHelpLink>
 
-#endif
-
 using namespace Core;
 using namespace Help;
 using namespace Help::Internal;
@@ -78,70 +65,6 @@ HelpIndexFilter::HelpIndexFilter()
 
 HelpIndexFilter::~HelpIndexFilter() = default;
 
-#ifndef HELP_NEW_FILTER_ENGINE
-
-void HelpIndexFilter::prepareSearch(const QString &entry)
-{
-    Q_UNUSED(entry)
-    QStringList namespaces = HelpManager::registeredNamespaces();
-    m_helpDatabases = Utils::transform(namespaces, &HelpManager::fileFromNamespace);
-}
-
-QList<LocatorFilterEntry> HelpIndexFilter::matchesFor(QFutureInterface<LocatorFilterEntry> &future, const QString &entry)
-{
-    if (m_needsUpdate.exchange(false) || m_searchTermCache.size() < 2
-            || m_searchTermCache.isEmpty() || !entry.contains(m_searchTermCache)) {
-        int limit = entry.size() < 2 ? 200 : INT_MAX;
-        QSet<QString> results;
-        for (const QString &filePath : qAsConst(m_helpDatabases)) {
-            if (future.isCanceled())
-                return QList<LocatorFilterEntry>();
-            QSet<QString> result;
-            QMetaObject::invokeMethod(this, "searchMatches", Qt::BlockingQueuedConnection,
-                                      Q_RETURN_ARG(QSet<QString>, result),
-                                      Q_ARG(QString, filePath),
-                                      Q_ARG(QString, entry),
-                                      Q_ARG(int, limit));
-            results.unite(result);
-        }
-        m_keywordCache = results;
-        m_searchTermCache = entry;
-    }
-
-    Qt::CaseSensitivity cs = caseSensitivity(entry);
-    QList<LocatorFilterEntry> entries;
-    QStringList keywords;
-    QStringList unsortedKeywords;
-    keywords.reserve(m_keywordCache.size());
-    unsortedKeywords.reserve(m_keywordCache.size());
-    QSet<QString> allresults;
-    for (const QString &keyword : qAsConst(m_keywordCache)) {
-        if (future.isCanceled())
-            return QList<LocatorFilterEntry>();
-        if (keyword.startsWith(entry, cs)) {
-            keywords.append(keyword);
-            allresults.insert(keyword);
-        } else if (keyword.contains(entry, cs)) {
-            unsortedKeywords.append(keyword);
-            allresults.insert(keyword);
-        }
-    }
-    Utils::sort(keywords);
-    keywords << unsortedKeywords;
-    m_keywordCache = allresults;
-    m_searchTermCache = entry;
-    for (const QString &keyword : qAsConst(keywords)) {
-        const int index = keyword.indexOf(entry, 0, cs);
-        LocatorFilterEntry filterEntry(this, keyword, QVariant(), m_icon);
-        filterEntry.highlightInfo = {index, entry.length()};
-        entries.append(filterEntry);
-    }
-
-    return entries;
-}
-
-#else
-
 bool HelpIndexFilter::updateCache(QFutureInterface<LocatorFilterEntry> &future,
                                   const QStringList &cache, const QString &entry)
 {
@@ -195,8 +118,6 @@ QList<LocatorFilterEntry> HelpIndexFilter::matchesFor(QFutureInterface<LocatorFi
     return entries;
 }
 
-#endif
-
 void HelpIndexFilter::accept(const LocatorFilterEntry &selection,
                              QString *newText, int *selectionStart, int *selectionLength) const
 {
@@ -204,14 +125,10 @@ void HelpIndexFilter::accept(const LocatorFilterEntry &selection,
     Q_UNUSED(selectionStart)
     Q_UNUSED(selectionLength)
     const QString &key = selection.displayName;
-#ifndef HELP_NEW_FILTER_ENGINE
-    const QMultiMap<QString, QUrl> &links = HelpManager::instance()->linksForKeyword(key);
-#else
     QMultiMap<QString, QUrl> links;
     const QList<QHelpLink> docs = LocalHelpManager::helpEngine().documentsForKeyword(key, QString());
     for (const auto &doc : docs)
         links.insert(doc.title, doc.url);
-#endif
     emit linksActivated(links, key);
 }
 
@@ -221,48 +138,12 @@ void HelpIndexFilter::refresh(QFutureInterface<void> &future)
     invalidateCache();
 }
 
-#ifndef HELP_NEW_FILTER_ENGINE
-
-QSet<QString> HelpIndexFilter::searchMatches(const QString &databaseFilePath,
-                                           const QString &term, int limit)
-{
-    static const QLatin1String sqlite("QSQLITE");
-    static const QLatin1String name("HelpManager::findKeywords");
-
-    QSet<QString> keywords;
-
-    { // make sure db is destroyed before removeDatabase call
-        QSqlDatabase db = QSqlDatabase::addDatabase(sqlite, name);
-        if (db.driver() && db.driver()->lastError().type() == QSqlError::NoError) {
-            db.setDatabaseName(databaseFilePath);
-            if (db.open()) {
-                QSqlQuery query = QSqlQuery(db);
-                query.setForwardOnly(true);
-                query.exec(QString::fromLatin1("SELECT DISTINCT Name FROM IndexTable WHERE Name LIKE "
-                    "'%%1%' LIMIT %2").arg(term, QString::number(limit)));
-                while (query.next()) {
-                    const QString &keyValue = query.value(0).toString();
-                    if (!keyValue.isEmpty())
-                        keywords.insert(keyValue);
-                }
-                db.close();
-            }
-        }
-    }
-    QSqlDatabase::removeDatabase(name);
-    return keywords;
-}
-
-#else
-
 QStringList HelpIndexFilter::allIndices() const
 {
     LocalHelpManager::setupGuiHelpEngine();
     return LocalHelpManager::filterEngine()->indices(QString());
 }
 
-#endif
-
 void HelpIndexFilter::invalidateCache()
 {
     m_needsUpdate = true;
diff --git a/src/plugins/help/helpindexfilter.h b/src/plugins/help/helpindexfilter.h
index fe8a3d89547..5c5520ae102 100644
--- a/src/plugins/help/helpindexfilter.h
+++ b/src/plugins/help/helpindexfilter.h
@@ -52,13 +52,7 @@ public:
                 QString *newText, int *selectionStart, int *selectionLength) const override;
     void refresh(QFutureInterface<void> &future) override;
 
-#ifndef HELP_NEW_FILTER_ENGINE
-    void prepareSearch(const QString &entry) override;
-    Q_INVOKABLE QSet<QString> searchMatches(const QString &databaseFilePath,
-                                          const QString &term, int limit);
-#else
     Q_INVOKABLE QStringList allIndices() const;
-#endif
 
 signals:
     void linksActivated(const QMultiMap<QString, QUrl> &links, const QString &key) const;
@@ -66,18 +60,12 @@ signals:
 private:
     void invalidateCache();
 
-#ifndef HELP_NEW_FILTER_ENGINE
-    QStringList m_helpDatabases;
-    QSet<QString> m_keywordCache;
-    QString m_searchTermCache;
-#else
     bool updateCache(QFutureInterface<Core::LocatorFilterEntry> &future,
                      const QStringList &cache, const QString &entry);
 
     QStringList m_allIndicesCache;
     QStringList m_lastIndicesCache;
     QString m_lastEntry;
-#endif
     std::atomic_bool m_needsUpdate = true;
     QIcon m_icon;
 };
diff --git a/src/plugins/help/helpmanager.cpp b/src/plugins/help/helpmanager.cpp
index c3f4dd738b6..d6d94b7d981 100644
--- a/src/plugins/help/helpmanager.cpp
+++ b/src/plugins/help/helpmanager.cpp
@@ -44,14 +44,7 @@
 
 #include <QMutexLocker>
 
-#ifndef HELP_NEW_FILTER_ENGINE
-#include <QSqlDatabase>
-#include <QSqlDriver>
-#include <QSqlError>
-#include <QSqlQuery>
-#else
 #include <QtHelp/QHelpLink>
-#endif
 
 using namespace Core;
 
@@ -89,19 +82,6 @@ struct HelpManagerPrivate
 static HelpManager *m_instance = nullptr;
 static HelpManagerPrivate *d = nullptr;
 
-#ifndef HELP_NEW_FILTER_ENGINE
-
-// -- DbCleaner
-
-struct DbCleaner
-{
-    DbCleaner(const QString &dbName) : name(dbName) {}
-    ~DbCleaner() { QSqlDatabase::removeDatabase(name); }
-    QString name;
-};
-
-#endif
-
 // -- HelpManager
 
 HelpManager::HelpManager(QObject *parent) :
@@ -243,15 +223,11 @@ 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
 }
 
 QMultiMap<QString, QUrl> HelpManager::linksForIdentifier(const QString &id)
@@ -259,15 +235,11 @@ 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)
@@ -321,76 +293,6 @@ 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 {});
-
-    Filters filters;
-    const QStringList &customFilters = d->m_helpEngine->customFilters();
-    for (const QString &filter : customFilters)
-        filters.insert(filter, d->m_helpEngine->filterAttributes(filter));
-    return filters;
-}
-
-HelpManager::Filters HelpManager::fixedFilters()
-{
-    QTC_ASSERT(!d->m_needsSetup, return {});
-
-    const QLatin1String sqlite("QSQLITE");
-    const QLatin1String name("HelpManager::fixedCustomFilters");
-
-    Filters fixedFilters;
-    DbCleaner cleaner(name);
-    QSqlDatabase db = QSqlDatabase::addDatabase(sqlite, name);
-    if (db.driver() && db.driver()->lastError().type() == QSqlError::NoError) {
-        const QStringList &registeredDocs = d->m_helpEngine->registeredDocumentations();
-        for (const QString &nameSpace : registeredDocs) {
-            db.setDatabaseName(d->m_helpEngine->documentationFileName(nameSpace));
-            if (db.open()) {
-                QSqlQuery query = QSqlQuery(db);
-                query.setForwardOnly(true);
-                query.exec(QLatin1String("SELECT Name FROM FilterNameTable"));
-                while (query.next()) {
-                    const QString &filter = query.value(0).toString();
-                    fixedFilters.insert(filter, d->m_helpEngine->filterAttributes(filter));
-                }
-            }
-        }
-    }
-    return fixedFilters;
-}
-
-HelpManager::Filters HelpManager::userDefinedFilters()
-{
-    QTC_ASSERT(!d->m_needsSetup, return {});
-
-    Filters all = filters();
-    const Filters &fixed = fixedFilters();
-    for (Filters::const_iterator it = fixed.constBegin(); it != fixed.constEnd(); ++it)
-        all.remove(it.key());
-    return all;
-}
-
-void HelpManager::removeUserDefinedFilter(const QString &filter)
-{
-    QTC_ASSERT(!d->m_needsSetup, return);
-
-    if (d->m_helpEngine->removeCustomFilter(filter))
-        emit m_instance->collectionFileChanged();
-}
-
-void HelpManager::addUserDefinedFilter(const QString &filter, const QStringList &attr)
-{
-    QTC_ASSERT(!d->m_needsSetup, return);
-
-    if (d->m_helpEngine->addCustomFilter(filter, attr))
-        emit m_instance->collectionFileChanged();
-}
-
-#endif
-
 void HelpManager::aboutToShutdown()
 {
     if (d && d->m_registerFuture.isRunning()) {
@@ -414,9 +316,7 @@ void HelpManager::setupHelpManager()
 #if QT_VERSION >= QT_VERSION_CHECK(6, 0, 0)
     d->m_helpEngine->setReadOnly(false);
 #endif
-#ifdef HELP_NEW_FILTER_ENGINE
     d->m_helpEngine->setUsesFilterEngine(true);
-#endif
     d->m_helpEngine->setupData();
 
     for (const QString &filePath : d->documentationFromInstaller())
diff --git a/src/plugins/help/helpmanager.h b/src/plugins/help/helpmanager.h
index 6edaae859b8..c6a1580a586 100644
--- a/src/plugins/help/helpmanager.h
+++ b/src/plugins/help/helpmanager.h
@@ -67,17 +67,6 @@ public:
     static void setCustomValue(const QString &key, const QVariant &value);
     static QVariant customValue(const QString &key, const QVariant &value = QVariant());
 
-#ifndef HELP_NEW_FILTER_ENGINE
-    using Filters = QHash<QString, QStringList>;
-
-    static Filters filters();
-    static Filters fixedFilters();
-
-    static Filters userDefinedFilters();
-    static void removeUserDefinedFilter(const QString &filter);
-    static void addUserDefinedFilter(const QString &filter, const QStringList &attr);
-#endif
-
     static void aboutToShutdown();
 
     Q_INVOKABLE void showHelpUrl(
diff --git a/src/plugins/help/helpplugin.cpp b/src/plugins/help/helpplugin.cpp
index bb0d45587f7..624ae6617d0 100644
--- a/src/plugins/help/helpplugin.cpp
+++ b/src/plugins/help/helpplugin.cpp
@@ -123,10 +123,6 @@ public:
 
     void slotSystemInformation();
 
-#ifndef HELP_NEW_FILTER_ENGINE
-    void resetFilter();
-#endif
-
     static void activateHelpMode() { ModeManager::activateMode(Constants::ID_MODE_HELP); }
     static bool canShowHelpSideBySide();
 
@@ -320,44 +316,6 @@ ExtensionSystem::IPlugin::ShutdownFlag HelpPlugin::aboutToShutdown()
     return SynchronousShutdown;
 }
 
-#ifndef HELP_NEW_FILTER_ENGINE
-
-void HelpPluginPrivate::resetFilter()
-{
-    const QString &filterInternal = QString::fromLatin1("Qt Creator %1.%2.%3")
-        .arg(IDE_VERSION_MAJOR).arg(IDE_VERSION_MINOR).arg(IDE_VERSION_RELEASE);
-    const QRegularExpression filterRegExp("^Qt Creator \\d*\\.\\d*\\.\\d*$");
-
-    QHelpEngineCore *engine = &LocalHelpManager::helpEngine();
-    const QStringList &filters = engine->customFilters();
-    for (const QString &filter : filters) {
-        if (filterRegExp.match(filter).hasMatch() && filter != filterInternal)
-            engine->removeCustomFilter(filter);
-    }
-
-    // we added a filter at some point, remove previously added filter
-    if (engine->customValue(Help::Constants::WeAddedFilterKey).toInt() == 1) {
-        const QString &filter =
-            engine->customValue(Help::Constants::PreviousFilterNameKey).toString();
-        if (!filter.isEmpty())
-            engine->removeCustomFilter(filter);
-    }
-
-    // potentially remove a filter with new name
-    const QString filterName = HelpPlugin::tr("Unfiltered");
-    engine->removeCustomFilter(filterName);
-    engine->addCustomFilter(filterName, QStringList());
-    engine->setCustomValue(Help::Constants::WeAddedFilterKey, 1);
-    engine->setCustomValue(Help::Constants::PreviousFilterNameKey, filterName);
-    engine->setCurrentFilter(filterName);
-
-    LocalHelpManager::updateFilterModel();
-    connect(engine, &QHelpEngineCore::setupFinished,
-            LocalHelpManager::instance(), &LocalHelpManager::updateFilterModel);
-}
-
-#endif
-
 void HelpPluginPrivate::saveExternalWindowSettings()
 {
     if (!m_externalWindow)
@@ -698,9 +656,6 @@ void HelpPluginPrivate::doSetupIfNeeded()
 {
     LocalHelpManager::setupGuiHelpEngine();
     if (m_setupNeeded) {
-#ifndef HELP_NEW_FILTER_ENGINE
-        resetFilter();
-#endif
         m_setupNeeded = false;
         m_centralWidget->openPagesManager()->setupInitialPages();
         LocalHelpManager::bookmarkManager().setupBookmarkModels();
diff --git a/src/plugins/help/helpwidget.cpp b/src/plugins/help/helpwidget.cpp
index 528f4de7592..74462c643b6 100644
--- a/src/plugins/help/helpwidget.cpp
+++ b/src/plugins/help/helpwidget.cpp
@@ -61,10 +61,8 @@
 #include <QStatusBar>
 #include <QToolButton>
 
-#ifdef HELP_NEW_FILTER_ENGINE
 #include <QtHelp/QHelpEngine>
 #include <QtHelp/QHelpFilterEngine>
-#endif
 
 static const char kWindowSideBarSettingsKey[] = "Help/WindowSideBar";
 static const char kModeSideBarSettingsKey[] = "Help/ModeSideBar";
@@ -365,23 +363,12 @@ HelpWidget::HelpWidget(const Core::Context &context, WidgetStyle style, QWidget
         m_filterComboBox = new QComboBox;
         m_filterComboBox->setMinimumContentsLength(15);
         layout->addWidget(m_filterComboBox);
-#ifndef HELP_NEW_FILTER_ENGINE
-        m_filterComboBox->setModel(LocalHelpManager::filterModel());
-        m_filterComboBox->setCurrentIndex(LocalHelpManager::filterIndex());
-        connect(m_filterComboBox, QOverload<int>::of(&QComboBox::activated),
-                LocalHelpManager::instance(), &LocalHelpManager::setFilterIndex);
-        connect(LocalHelpManager::instance(),
-                &LocalHelpManager::filterIndexChanged,
-                m_filterComboBox,
-                &QComboBox::setCurrentIndex);
-#else
         connect(&LocalHelpManager::helpEngine(), &QHelpEngine::setupFinished,
                 this, &HelpWidget::setupFilterCombo, Qt::QueuedConnection);
         connect(m_filterComboBox, QOverload<int>::of(&QComboBox::activated),
                 this, &HelpWidget::filterDocumentation);
         connect(LocalHelpManager::filterEngine(), &QHelpFilterEngine::filterActivated,
                 this, &HelpWidget::currentFilterChanged);
-#endif
 
         Core::ActionContainer *windowMenu = Core::ActionManager::actionContainer(
             Core::Constants::M_WINDOW);
@@ -501,8 +488,6 @@ HelpWidget::HelpWidget(const Core::Context &context, WidgetStyle style, QWidget
     }
 }
 
-#ifdef HELP_NEW_FILTER_ENGINE
-
 void HelpWidget::setupFilterCombo()
 {
     const QString currentFilter = LocalHelpManager::filterEngine()->activeFilter();
@@ -534,8 +519,6 @@ void HelpWidget::currentFilterChanged(const QString &filter)
     m_filterComboBox->setCurrentIndex(index);
 }
 
-#endif
-
 HelpWidget::~HelpWidget()
 {
     saveState();
diff --git a/src/plugins/help/helpwidget.h b/src/plugins/help/helpwidget.h
index 55f90a8e566..8ac5b646b26 100644
--- a/src/plugins/help/helpwidget.h
+++ b/src/plugins/help/helpwidget.h
@@ -142,11 +142,9 @@ private:
     void addSideBar();
     QString sideBarSettingsKey() const;
 
-#ifdef HELP_NEW_FILTER_ENGINE
     void setupFilterCombo();
     void filterDocumentation(int filterIndex);
     void currentFilterChanged(const QString &filter);
-#endif
 
     OpenPagesModel m_model;
     OpenPagesManager *m_openPagesManager = nullptr;
diff --git a/src/plugins/help/localhelpmanager.cpp b/src/plugins/help/localhelpmanager.cpp
index 99c73c200d4..30eabc65e6c 100644
--- a/src/plugins/help/localhelpmanager.cpp
+++ b/src/plugins/help/localhelpmanager.cpp
@@ -69,14 +69,6 @@ QHelpEngine* LocalHelpManager::m_guiEngine = nullptr;
 QMutex LocalHelpManager::m_bkmarkMutex;
 BookmarkManager* LocalHelpManager::m_bookmarkManager = nullptr;
 
-#ifndef HELP_NEW_FILTER_ENGINE
-
-QStandardItemModel *LocalHelpManager::m_filterModel = nullptr;
-QString LocalHelpManager::m_currentFilter = QString();
-int LocalHelpManager::m_currentFilterIndex = -1;
-
-#endif
-
 static const char kHelpHomePageKey[] = "Help/HomePage";
 static const char kFontFamilyKey[] = "Help/FallbackFontFamily";
 static const char kFontStyleNameKey[] = "Help/FallbackFontStyleName";
@@ -118,9 +110,6 @@ LocalHelpManager::LocalHelpManager(QObject *parent)
 {
     m_instance = this;
     qRegisterMetaType<Help::Internal::LocalHelpManager::HelpData>("Help::Internal::LocalHelpManager::HelpData");
-#ifndef HELP_NEW_FILTER_ENGINE
-    m_filterModel = new QStandardItemModel(this);
-#endif
 }
 
 LocalHelpManager::~LocalHelpManager()
@@ -414,9 +403,7 @@ QHelpEngine &LocalHelpManager::helpEngine()
             m_guiEngine->setReadOnly(false);
 #endif
 
-#ifdef HELP_NEW_FILTER_ENGINE
             m_guiEngine->setUsesFilterEngine(true);
-#endif
         }
     }
     return *m_guiEngine;
@@ -515,66 +502,11 @@ LocalHelpManager::HelpData LocalHelpManager::helpData(const QUrl &url)
     return data;
 }
 
-#ifndef HELP_NEW_FILTER_ENGINE
-
-QAbstractItemModel *LocalHelpManager::filterModel()
-{
-    return m_filterModel;
-}
-
-void LocalHelpManager::setFilterIndex(int index)
-{
-    if (index == m_currentFilterIndex)
-        return;
-    m_currentFilterIndex = index;
-    QStandardItem *item = m_filterModel->item(index);
-    if (!item) {
-        helpEngine().setCurrentFilter(QString());
-        return;
-    }
-    helpEngine().setCurrentFilter(item->text());
-    emit m_instance->filterIndexChanged(m_currentFilterIndex);
-}
-
-int LocalHelpManager::filterIndex()
-{
-    return m_currentFilterIndex;
-}
-
-void LocalHelpManager::updateFilterModel()
-{
-    const QHelpEngine &engine = helpEngine();
-    if (m_currentFilter.isEmpty())
-        m_currentFilter = engine.currentFilter();
-    m_filterModel->clear();
-    m_currentFilterIndex = -1;
-    int count = 0;
-    const QStringList &filters = engine.customFilters();
-    foreach (const QString &filterString, filters) {
-        m_filterModel->appendRow(new QStandardItem(filterString));
-        if (filterString == m_currentFilter)
-            m_currentFilterIndex = count;
-        count++;
-    }
-
-    if (filters.size() < 1)
-        return;
-    if (m_currentFilterIndex < 0) {
-        m_currentFilterIndex = 0;
-        m_currentFilter = filters.at(0);
-    }
-    emit m_instance->filterIndexChanged(m_currentFilterIndex);
-}
-
-#else
-
 QHelpFilterEngine *LocalHelpManager::filterEngine()
 {
     return helpEngine().filterEngine();
 }
 
-#endif
-
 bool LocalHelpManager::canOpenOnlineHelp(const QUrl &url)
 {
     const QString address = url.toString();
diff --git a/src/plugins/help/localhelpmanager.h b/src/plugins/help/localhelpmanager.h
index 467987698b5..0a895c1559c 100644
--- a/src/plugins/help/localhelpmanager.h
+++ b/src/plugins/help/localhelpmanager.h
@@ -31,13 +31,8 @@
 #include <QMutex>
 #include <QObject>
 #include <QUrl>
-#ifndef HELP_NEW_FILTER_ENGINE
-#include <QStandardItemModel>
-#include <functional>
-#else
-QT_FORWARD_DECLARE_CLASS(QHelpFilterEngine)
-#endif
 
+QT_FORWARD_DECLARE_CLASS(QHelpFilterEngine)
 QT_FORWARD_DECLARE_CLASS(QHelpEngine)
 
 class BookmarkManager;
@@ -119,23 +114,12 @@ public:
     static QByteArray loadErrorMessage(const QUrl &url, const QString &errorString);
     Q_INVOKABLE static Help::Internal::LocalHelpManager::HelpData helpData(const QUrl &url);
 
-#ifndef HELP_NEW_FILTER_ENGINE
-    static QAbstractItemModel *filterModel();
-    static void setFilterIndex(int index);
-    static int filterIndex();
-
-    static void updateFilterModel();
-#else
     static QHelpFilterEngine *filterEngine();
-#endif
 
     static bool canOpenOnlineHelp(const QUrl &url);
     static bool openOnlineHelp(const QUrl &url);
 
 signals:
-#ifndef HELP_NEW_FILTER_ENGINE
-    void filterIndexChanged(int index);
-#endif
     void fallbackFontChanged(const QFont &font);
     void fontZoomChanged(int percentage);
     void returnOnCloseChanged();
@@ -146,12 +130,6 @@ private:
     static bool m_guiNeedsSetup;
     static bool m_needsCollectionFile;
 
-#ifndef HELP_NEW_FILTER_ENGINE
-    static QStandardItemModel *m_filterModel;
-    static QString m_currentFilter;
-    static int m_currentFilterIndex;
-#endif
-
     static QMutex m_guiMutex;
     static QHelpEngine *m_guiEngine;
 
diff --git a/src/shared/help/CMakeLists.txt b/src/shared/help/CMakeLists.txt
index c3a864da6e9..aba90cda07a 100644
--- a/src/shared/help/CMakeLists.txt
+++ b/src/shared/help/CMakeLists.txt
@@ -28,8 +28,3 @@ add_qtc_library(shared_help STATIC
     indexwindow.cpp indexwindow.h
     topicchooser.cpp topicchooser.h topicchooser.ui
 )
-
-extend_qtc_library(shared_help
-  CONDITION Qt5_VERSION VERSION_GREATER_EQUAL 5.15.0
-  DEFINES HELP_NEW_FILTER_ENGINE
-)
diff --git a/src/shared/help/indexwindow.cpp b/src/shared/help/indexwindow.cpp
index fcf8bf52e3a..8fe33563431 100644
--- a/src/shared/help/indexwindow.cpp
+++ b/src/shared/help/indexwindow.cpp
@@ -48,9 +48,7 @@
 #include <QHelpEngine>
 #include <QHelpIndexModel>
 
-#ifdef HELP_NEW_FILTER_ENGINE
 #include <QHelpLink>
-#endif
 
 using namespace Help::Internal;
 
@@ -198,15 +196,11 @@ void IndexWindow::disableSearchLineEdit()
 void IndexWindow::open(const QModelIndex &index, bool newPage)
 {
     const QString keyword = m_filteredIndexModel->data(index, Qt::DisplayRole).toString();
-#ifndef HELP_NEW_FILTER_ENGINE
-    QMultiMap<QString, QUrl> links = LocalHelpManager::helpEngine().linksForKeyword(keyword);
-#else
     QMultiMap<QString, QUrl> links;
     const QList<QHelpLink> docs = LocalHelpManager::helpEngine().documentsForKeyword(keyword);
     for (const auto &doc : docs)
         links.insert(doc.title, doc.url);
 
-#endif
     emit linksActivated(links, keyword, newPage);
 }