X-Git-Url: https://cloud.milkyroute.net/gitweb/dolphin.git/blobdiff_plain/dd9405bf2f628bd28580737cc46335343074be0d..b4e80645e8e39ef7fcc1545136bad06ab3dd5f3e:/src/kitemviews/kfileitemmodel.cpp

diff --git a/src/kitemviews/kfileitemmodel.cpp b/src/kitemviews/kfileitemmodel.cpp
index 1335778e7..603c16e0d 100644
--- a/src/kitemviews/kfileitemmodel.cpp
+++ b/src/kitemviews/kfileitemmodel.cpp
@@ -8,76 +8,79 @@
 
 #include "kfileitemmodel.h"
 
+#include "dolphin_contentdisplaysettings.h"
 #include "dolphin_generalsettings.h"
-#include "dolphin_detailsmodesettings.h"
 #include "dolphindebug.h"
-#include "private/kfileitemmodeldirlister.h"
 #include "private/kfileitemmodelsortalgorithm.h"
+#include "views/draganddrophelper.h"
 
-#include <kio_version.h>
+#include <KDirLister>
+#include <KIO/Job>
+#include <KIO/ListJob>
 #include <KLocalizedString>
 #include <KUrlMimeData>
 
+#ifndef QT_NO_ACCESSIBILITY
+#include <QAccessible>
+#endif
 #include <QElapsedTimer>
+#include <QIcon>
 #include <QMimeData>
 #include <QMimeDatabase>
+#include <QRecursiveMutex>
 #include <QTimer>
 #include <QWidget>
-#include <QMutex>
-#include <QIcon>
+#include <klazylocalizedstring.h>
 
-Q_GLOBAL_STATIC_WITH_ARGS(QMutex, s_collatorMutex, (QMutex::Recursive))
+Q_GLOBAL_STATIC(QRecursiveMutex, s_collatorMutex)
 
 // #define KFILEITEMMODEL_DEBUG
 
-KFileItemModel::KFileItemModel(QObject* parent) :
-    KItemModelBase("text", parent),
-    m_dirLister(nullptr),
-    m_sortDirsFirst(true),
-    m_sortRole(NameRole),
-    m_sortingProgressPercent(-1),
-    m_roles(),
-    m_itemData(),
-    m_items(),
-    m_filter(),
-    m_filteredItems(),
-    m_requestRole(),
-    m_maximumUpdateIntervalTimer(nullptr),
-    m_resortAllItemsTimer(nullptr),
-    m_pendingItemsToInsert(),
-    m_groups(),
-    m_expandedDirs(),
-    m_urlsToExpand()
+KFileItemModel::KFileItemModel(QObject *parent)
+    : KItemModelBase("text", "none", parent)
+    , m_dirLister(nullptr)
+    , m_sortDirsFirst(true)
+    , m_sortHiddenLast(false)
+    , m_sortRole(NameRole)
+    , m_groupRole(NoRole)
+    , m_sortingProgressPercent(-1)
+    , m_roles()
+    , m_itemData()
+    , m_items()
+    , m_filter()
+    , m_filteredItems()
+    , m_requestRole()
+    , m_maximumUpdateIntervalTimer(nullptr)
+    , m_resortAllItemsTimer(nullptr)
+    , m_pendingItemsToInsert()
+    , m_groups()
+    , m_expandedDirs()
+    , m_urlsToExpand()
 {
     m_collator.setNumericMode(true);
 
     loadSortingSettings();
 
-    m_dirLister = new KFileItemModelDirLister(this);
+    m_dirLister = new KDirLister(this);
+    m_dirLister->setAutoErrorHandlingEnabled(false);
     m_dirLister->setDelayedMimeTypes(true);
 
-    const QWidget* parentWidget = qobject_cast<QWidget*>(parent);
+    const QWidget *parentWidget = qobject_cast<QWidget *>(parent);
     if (parentWidget) {
         m_dirLister->setMainWindow(parentWidget->window());
     }
 
-    connect(m_dirLister, &KFileItemModelDirLister::started, this, &KFileItemModel::directoryLoadingStarted);
-    connect(m_dirLister, QOverload<>::of(&KCoreDirLister::canceled), this, &KFileItemModel::slotCanceled);
-    connect(m_dirLister, &KFileItemModelDirLister::itemsAdded, this, &KFileItemModel::slotItemsAdded);
-    connect(m_dirLister, &KFileItemModelDirLister::itemsDeleted, this, &KFileItemModel::slotItemsDeleted);
-    connect(m_dirLister, &KFileItemModelDirLister::refreshItems, this, &KFileItemModel::slotRefreshItems);
-    connect(m_dirLister, QOverload<>::of(&KCoreDirLister::clear), this, &KFileItemModel::slotClear);
-    connect(m_dirLister, &KFileItemModelDirLister::infoMessage, this, &KFileItemModel::infoMessage);
-    connect(m_dirLister, &KFileItemModelDirLister::errorMessage, this, &KFileItemModel::errorMessage);
-    connect(m_dirLister, &KFileItemModelDirLister::percent, this, &KFileItemModel::directoryLoadingProgress);
-    connect(m_dirLister, QOverload<const QUrl&, const QUrl&>::of(&KCoreDirLister::redirection), this, &KFileItemModel::directoryRedirection);
-    connect(m_dirLister, &KFileItemModelDirLister::urlIsFileError, this, &KFileItemModel::urlIsFileError);
-
-#if KIO_VERSION < QT_VERSION_CHECK(5, 79, 0)
-    connect(m_dirLister, QOverload<const QUrl&>::of(&KCoreDirLister::completed), this, &KFileItemModel::slotCompleted);
-#else
+    connect(m_dirLister, &KCoreDirLister::started, this, &KFileItemModel::directoryLoadingStarted);
+    connect(m_dirLister, &KCoreDirLister::canceled, this, &KFileItemModel::slotCanceled);
+    connect(m_dirLister, &KCoreDirLister::itemsAdded, this, &KFileItemModel::slotItemsAdded);
+    connect(m_dirLister, &KCoreDirLister::itemsDeleted, this, &KFileItemModel::slotItemsDeleted);
+    connect(m_dirLister, &KCoreDirLister::refreshItems, this, &KFileItemModel::slotRefreshItems);
+    connect(m_dirLister, &KCoreDirLister::clear, this, &KFileItemModel::slotClear);
+    connect(m_dirLister, &KCoreDirLister::infoMessage, this, &KFileItemModel::infoMessage);
+    connect(m_dirLister, &KCoreDirLister::jobError, this, &KFileItemModel::slotListerError);
+    connect(m_dirLister, &KCoreDirLister::percent, this, &KFileItemModel::directoryLoadingProgress);
+    connect(m_dirLister, &KCoreDirLister::redirection, this, &KFileItemModel::directoryRedirection);
     connect(m_dirLister, &KCoreDirLister::listingDirCompleted, this, &KFileItemModel::slotCompleted);
-#endif
 
     // Apply default roles that should be determined
     resetRoles();
@@ -101,11 +104,14 @@ KFileItemModel::KFileItemModel(QObject* parent) :
     // for a lot of items within a quite small timeslot. To prevent expensive resortings the
     // resorting is postponed until the timer has been exceeded.
     m_resortAllItemsTimer = new QTimer(this);
-    m_resortAllItemsTimer->setInterval(500);
+    m_resortAllItemsTimer->setInterval(100); // 100 is a middle ground between sorting too frequently which makes the view unreadable
+                                             // and sorting too infrequently which leads to users seeing an outdated sort order.
     m_resortAllItemsTimer->setSingleShot(true);
     connect(m_resortAllItemsTimer, &QTimer::timeout, this, &KFileItemModel::resortAllItems);
 
     connect(GeneralSettings::self(), &GeneralSettings::sortingChoiceChanged, this, &KFileItemModel::slotSortingChoiceChanged);
+
+    setShowTrashMime(m_dirLister->showHiddenFiles() || !GeneralSettings::hideXTrashFile());
 }
 
 KFileItemModel::~KFileItemModel()
@@ -130,6 +136,8 @@ void KFileItemModel::refreshDirectory(const QUrl &url)
     }
 
     m_dirLister->openUrl(url, KDirLister::Reload);
+
+    Q_EMIT directoryRefreshing();
 }
 
 QUrl KFileItemModel::directory() const
@@ -150,9 +158,21 @@ int KFileItemModel::count() const
 QHash<QByteArray, QVariant> KFileItemModel::data(int index) const
 {
     if (index >= 0 && index < count()) {
-        ItemData* data = m_itemData.at(index);
+        ItemData *data = m_itemData.at(index);
         if (data->values.isEmpty()) {
             data->values = retrieveData(data->item, data->parent);
+        } else if (data->values.count() <= 2 && data->values.value("isExpanded").toBool()) {
+            // Special case dealt by slotRefreshItems(), avoid losing the "isExpanded" and "expandedParentsCount" state when refreshing
+            // slotRefreshItems() makes sure folders keep the "isExpanded" and "expandedParentsCount" while clearing the remaining values
+            // so this special request of different behavior can be identified here.
+            bool hasExpandedParentsCount = false;
+            const int expandedParentsCount = data->values.value("expandedParentsCount").toInt(&hasExpandedParentsCount);
+
+            data->values = retrieveData(data->item, data->parent);
+            data->values.insert("isExpanded", true);
+            if (hasExpandedParentsCount) {
+                data->values.insert("expandedParentsCount", expandedParentsCount);
+            }
         }
 
         return data->values;
@@ -160,7 +180,7 @@ QHash<QByteArray, QVariant> KFileItemModel::data(int index) const
     return QHash<QByteArray, QVariant>();
 }
 
-bool KFileItemModel::setData(int index, const QHash<QByteArray, QVariant>& values)
+bool KFileItemModel::setData(int index, const QHash<QByteArray, QVariant> &values)
 {
     if (index < 0 || index >= count()) {
         return false;
@@ -186,13 +206,20 @@ bool KFileItemModel::setData(int index, const QHash<QByteArray, QVariant>& value
         return false;
     }
 
-    m_itemData[index]->values = currentValues;
     if (changedRoles.contains("text")) {
         QUrl url = m_itemData[index]->item.url();
+        m_items.remove(url);
         url = url.adjusted(QUrl::RemoveFilename);
         url.setPath(url.path() + currentValues["text"].toString());
         m_itemData[index]->item.setUrl(url);
+        m_items.insert(url, index);
+
+        if (!changedRoles.contains("url")) {
+            changedRoles.insert("url");
+            currentValues["url"] = url;
+        }
     }
+    m_itemData[index]->values = currentValues;
 
     emitItemsChangedAndTriggerResorting(KItemRangeList() << KItemRange(index, 1), changedRoles);
 
@@ -212,9 +239,44 @@ bool KFileItemModel::sortDirectoriesFirst() const
     return m_sortDirsFirst;
 }
 
+void KFileItemModel::setSortHiddenLast(bool hiddenLast)
+{
+    if (hiddenLast != m_sortHiddenLast) {
+        m_sortHiddenLast = hiddenLast;
+        resortAllItems();
+    }
+}
+
+bool KFileItemModel::sortHiddenLast() const
+{
+    return m_sortHiddenLast;
+}
+
+void KFileItemModel::setShowTrashMime(bool showTrashMime)
+{
+    const auto trashMime = QStringLiteral("application/x-trash");
+    QStringList excludeFilter = m_filter.excludeMimeTypes();
+
+    if (showTrashMime) {
+        excludeFilter.removeAll(trashMime);
+    } else if (!excludeFilter.contains(trashMime)) {
+        excludeFilter.append(trashMime);
+    }
+
+    setExcludeMimeTypeFilter(excludeFilter);
+}
+
+void KFileItemModel::scheduleResortAllItems()
+{
+    if (!m_resortAllItemsTimer->isActive()) {
+        m_resortAllItemsTimer->start();
+    }
+}
+
 void KFileItemModel::setShowHiddenFiles(bool show)
 {
-    m_dirLister->setShowingDotFiles(show);
+    m_dirLister->setShowHiddenFiles(show);
+    setShowTrashMime(show || !GeneralSettings::hideXTrashFile());
     m_dirLister->emitChanges();
     if (show) {
         dispatchPendingItemsToInsert();
@@ -223,7 +285,7 @@ void KFileItemModel::setShowHiddenFiles(bool show)
 
 bool KFileItemModel::showHiddenFiles() const
 {
-    return m_dirLister->showingDotFiles();
+    return m_dirLister->showHiddenFiles();
 }
 
 void KFileItemModel::setShowDirectoriesOnly(bool enabled)
@@ -236,20 +298,20 @@ bool KFileItemModel::showDirectoriesOnly() const
     return m_dirLister->dirOnlyMode();
 }
 
-QMimeData* KFileItemModel::createMimeData(const KItemSet& indexes) const
+QMimeData *KFileItemModel::createMimeData(const KItemSet &indexes) const
 {
-    QMimeData* data = new QMimeData();
+    QMimeData *data = new QMimeData();
 
     // The following code has been taken from KDirModel::mimeData()
     // (kdelibs/kio/kio/kdirmodel.cpp)
     // SPDX-FileCopyrightText: 2006 David Faure <faure@kde.org>
     QList<QUrl> urls;
     QList<QUrl> mostLocalUrls;
-    const ItemData* lastAddedItem = nullptr;
+    const ItemData *lastAddedItem = nullptr;
 
     for (int index : indexes) {
-        const ItemData* itemData = m_itemData.at(index);
-        const ItemData* parent = itemData->parent;
+        const ItemData *itemData = m_itemData.at(index);
+        const ItemData *parent = itemData->parent;
 
         while (parent && parent != lastAddedItem) {
             parent = parent->parent;
@@ -261,7 +323,7 @@ QMimeData* KFileItemModel::createMimeData(const KItemSet& indexes) const
         }
 
         lastAddedItem = itemData;
-        const KFileItem& item = itemData->item;
+        const KFileItem &item = itemData->item;
         if (!item.isNull()) {
             urls << item.url();
 
@@ -274,16 +336,32 @@ QMimeData* KFileItemModel::createMimeData(const KItemSet& indexes) const
     return data;
 }
 
-int KFileItemModel::indexForKeyboardSearch(const QString& text, int startFromIndex) const
+namespace
+{
+QString removeMarks(const QString &original)
+{
+    const auto normalized = original.normalized(QString::NormalizationForm_D);
+    QString res;
+    for (auto ch : normalized) {
+        if (!ch.isMark()) {
+            res.append(ch);
+        }
+    }
+    return res;
+}
+}
+
+int KFileItemModel::indexForKeyboardSearch(const QString &text, int startFromIndex) const
 {
+    const auto noMarkText = removeMarks(text);
     startFromIndex = qMax(0, startFromIndex);
     for (int i = startFromIndex; i < count(); ++i) {
-        if (fileItem(i).text().startsWith(text, Qt::CaseInsensitive)) {
+        if (removeMarks(fileItem(i).text()).startsWith(noMarkText, Qt::CaseInsensitive)) {
             return i;
         }
     }
     for (int i = 0; i < startFromIndex; ++i) {
-        if (fileItem(i).text().startsWith(text, Qt::CaseInsensitive)) {
+        if (removeMarks(fileItem(i).text()).startsWith(noMarkText, Qt::CaseInsensitive)) {
             return i;
         }
     }
@@ -292,37 +370,67 @@ int KFileItemModel::indexForKeyboardSearch(const QString& text, int startFromInd
 
 bool KFileItemModel::supportsDropping(int index) const
 {
-    const KFileItem item = fileItem(index);
+    KFileItem item;
+    if (index == -1) {
+        item = rootItem();
+    } else {
+        item = fileItem(index);
+    }
+    return !item.isNull() && DragAndDropHelper::supportsDropping(item);
+}
+
+bool KFileItemModel::canEnterOnHover(int index) const
+{
+    KFileItem item;
+    if (index == -1) {
+        item = rootItem();
+    } else {
+        item = fileItem(index);
+    }
     return !item.isNull() && (item.isDir() || item.isDesktopFile());
 }
 
-QString KFileItemModel::roleDescription(const QByteArray& role) const
+QString KFileItemModel::roleDescription(const QByteArray &role) const
 {
     static QHash<QByteArray, QString> description;
     if (description.isEmpty()) {
         int count = 0;
-        const RoleInfoMap* map = rolesInfoMap(count);
+        const RoleInfoMap *map = rolesInfoMap(count);
         for (int i = 0; i < count; ++i) {
-            if (!map[i].roleTranslation) {
+            if (map[i].roleTranslation.isEmpty()) {
                 continue;
             }
-            description.insert(map[i].role, i18nc(map[i].roleTranslationContext, map[i].roleTranslation));
+            description.insert(map[i].role, map[i].roleTranslation.toString());
         }
     }
 
     return description.value(role);
 }
 
-QList<QPair<int, QVariant> > KFileItemModel::groups() const
+QList<QPair<int, QVariant>> KFileItemModel::groups() const
 {
     if (!m_itemData.isEmpty() && m_groups.isEmpty()) {
 #ifdef KFILEITEMMODEL_DEBUG
         QElapsedTimer timer;
         timer.start();
 #endif
-        switch (typeForRole(sortRole())) {
-        case NameRole:        m_groups = nameRoleGroups(); break;
-        case SizeRole:        m_groups = sizeRoleGroups(); break;
+        QByteArray role = groupRole();
+        if (typeForRole(role) == NoRole) {
+            // Handle extra grouping information
+            if (m_groupExtraInfo == "followSort") {
+                role = sortRole();
+            }
+        }
+        switch (typeForRole(role)) {
+        case NoRole:
+            m_groups.clear();
+            break;
+        case NameRole:
+            m_groups = nameRoleGroups();
+            break;
+        case SizeRole:
+            m_groups = sizeRoleGroups();
+            break;
         case ModificationTimeRole:
             m_groups = timeRoleGroups([](const ItemData *item) {
                 return item->item.time(KFileItem::ModificationTime);
@@ -343,9 +451,15 @@ QList<QPair<int, QVariant> > KFileItemModel::groups() const
                 return item->values.value("deletiontime").toDateTime();
             });
             break;
-        case PermissionsRole: m_groups = permissionRoleGroups(); break;
-        case RatingRole:      m_groups = ratingRoleGroups(); break;
-        default:              m_groups = genericStringRoleGroups(sortRole()); break;
+        case PermissionsRole:
+            m_groups = permissionRoleGroups();
+            break;
+        case RatingRole:
+            m_groups = ratingRoleGroups();
+            break;
+        default:
+            m_groups = genericStringRoleGroups(role);
+            break;
         }
 
 #ifdef KFILEITEMMODEL_DEBUG
@@ -374,12 +488,12 @@ KFileItem KFileItemModel::fileItem(const QUrl &url) const
     return KFileItem();
 }
 
-int KFileItemModel::index(const KFileItem& item) const
+int KFileItemModel::index(const KFileItem &item) const
 {
     return index(item.url());
 }
 
-int KFileItemModel::index(const QUrl& url) const
+int KFileItemModel::index(const QUrl &url) const
 {
     const QUrl urlToFind = url.adjusted(QUrl::StripTrailingSlash);
 
@@ -429,13 +543,13 @@ int KFileItemModel::index(const QUrl& url) const
             }
 
             const auto uniqueKeys = indexesForUrl.uniqueKeys();
-            for (const QUrl& url : uniqueKeys) {
+            for (const QUrl &url : uniqueKeys) {
                 if (indexesForUrl.count(url) > 1) {
                     qCWarning(DolphinDebug) << "Multiple items found with the URL" << url;
 
                     auto it = indexesForUrl.find(url);
                     while (it != indexesForUrl.end() && it.key() == url) {
-                        const ItemData* data = m_itemData.at(it.value());
+                        const ItemData *data = m_itemData.at(it.value());
                         qCWarning(DolphinDebug) << "index" << it.value() << ":" << data->item;
                         if (data->parent) {
                             qCWarning(DolphinDebug) << "parent" << data->parent->item;
@@ -460,7 +574,7 @@ void KFileItemModel::clear()
     slotClear();
 }
 
-void KFileItemModel::setRoles(const QSet<QByteArray>& roles)
+void KFileItemModel::setRoles(const QSet<QByteArray> &roles)
 {
     if (m_roles == roles) {
         return;
@@ -484,7 +598,7 @@ void KFileItemModel::setRoles(const QSet<QByteArray>& roles)
 
     QSetIterator<QByteArray> it(roles);
     while (it.hasNext()) {
-        const QByteArray& role = it.next();
+        const QByteArray &role = it.next();
         m_requestRole[typeForRole(role)] = true;
     }
 
@@ -500,8 +614,8 @@ void KFileItemModel::setRoles(const QSet<QByteArray>& roles)
 
     // Clear the 'values' of all filtered items. They will be re-populated with the
     // correct roles the next time 'values' will be accessed via data(int).
-    QHash<KFileItem, ItemData*>::iterator filteredIt = m_filteredItems.begin();
-    const QHash<KFileItem, ItemData*>::iterator filteredEnd = m_filteredItems.end();
+    QHash<KFileItem, ItemData *>::iterator filteredIt = m_filteredItems.begin();
+    const QHash<KFileItem, ItemData *>::iterator filteredEnd = m_filteredItems.end();
     while (filteredIt != filteredEnd) {
         (*filteredIt)->values.clear();
         ++filteredIt;
@@ -533,7 +647,7 @@ bool KFileItemModel::setExpanded(int index, bool expanded)
         m_dirLister->openUrl(url, KDirLister::Keep);
 
         const QVariantList previouslyExpandedChildren = m_itemData.at(index)->values.value("previouslyExpandedChildren").value<QVariantList>();
-        for (const QVariant& var : previouslyExpandedChildren) {
+        for (const QVariant &var : previouslyExpandedChildren) {
             m_urlsToExpand.insert(var.toUrl());
         }
     } else {
@@ -551,6 +665,7 @@ bool KFileItemModel::setExpanded(int index, bool expanded)
 
         m_expandedDirs.remove(targetUrl);
         m_dirLister->stop(url);
+        m_dirLister->forgetDirs(url);
 
         const int parentLevel = expandedParentsCount(index);
         const int itemCount = m_itemData.count();
@@ -560,12 +675,13 @@ bool KFileItemModel::setExpanded(int index, bool expanded)
 
         int childIndex = firstChildIndex;
         while (childIndex < itemCount && expandedParentsCount(childIndex) > parentLevel) {
-            ItemData* itemData = m_itemData.at(childIndex);
+            ItemData *itemData = m_itemData.at(childIndex);
             if (itemData->values.value("isExpanded").toBool()) {
                 const QUrl targetUrl = itemData->item.targetUrl();
                 const QUrl url = itemData->item.url();
                 m_expandedDirs.remove(targetUrl);
-                m_dirLister->stop(url);     // TODO: try to unit-test this, see https://bugs.kde.org/show_bug.cgi?id=332102#c11
+                m_dirLister->stop(url); // TODO: try to unit-test this, see https://bugs.kde.org/show_bug.cgi?id=332102#c11
+                m_dirLister->forgetDirs(url);
                 expandedChildren.append(targetUrl);
             }
             ++childIndex;
@@ -624,7 +740,6 @@ void KFileItemModel::restoreExpandedDirectories(const QSet<QUrl> &urls)
 
 void KFileItemModel::expandParentDirectories(const QUrl &url)
 {
-
     // Assure that each sub-path of the URL that should be
     // expanded is added to m_urlsToExpand. KDirLister
     // does not care whether the parent-URL has already been
@@ -658,7 +773,7 @@ void KFileItemModel::expandParentDirectories(const QUrl &url)
     }
 }
 
-void KFileItemModel::setNameFilter(const QString& nameFilter)
+void KFileItemModel::setNameFilter(const QString &nameFilter)
 {
     if (m_filter.pattern() != nameFilter) {
         dispatchPendingItemsToInsert();
@@ -672,7 +787,7 @@ QString KFileItemModel::nameFilter() const
     return m_filter.pattern();
 }
 
-void KFileItemModel::setMimeTypeFilters(const QStringList& filters)
+void KFileItemModel::setMimeTypeFilters(const QStringList &filters)
 {
     if (m_filter.mimeTypes() != filters) {
         dispatchPendingItemsToInsert();
@@ -686,49 +801,103 @@ QStringList KFileItemModel::mimeTypeFilters() const
     return m_filter.mimeTypes();
 }
 
+void KFileItemModel::setExcludeMimeTypeFilter(const QStringList &filters)
+{
+    if (m_filter.excludeMimeTypes() != filters) {
+        dispatchPendingItemsToInsert();
+        m_filter.setExcludeMimeTypes(filters);
+        applyFilters();
+    }
+}
+
+QStringList KFileItemModel::excludeMimeTypeFilter() const
+{
+    return m_filter.excludeMimeTypes();
+}
 
 void KFileItemModel::applyFilters()
 {
-    // Check which shown items from m_itemData must get
-    // hidden and hence moved to m_filteredItems.
-    QVector<int> newFilteredIndexes;
+    // ===STEP 1===
+    // Check which previously shown items from m_itemData must now get
+    // hidden and hence moved from m_itemData into m_filteredItems.
 
-    const int itemCount = m_itemData.count();
-    for (int index = 0; index < itemCount; ++index) {
-        ItemData* itemData = m_itemData.at(index);
-
-        // Only filter non-expanded items as child items may never
-        // exist without a parent item
-        if (!itemData->values.value("isExpanded").toBool()) {
-            const KFileItem item = itemData->item;
-            if (!m_filter.matches(item)) {
-                newFilteredIndexes.append(index);
-                m_filteredItems.insert(item, itemData);
-            }
+    QList<int> newFilteredIndexes; // This structure is good for prepending. We will want an ascending sorted Container at the end, this will do fine.
+
+    // This pointer will refer to the next confirmed shown item from the point of
+    // view of the current "itemData" in the upcoming "for" loop.
+    ItemData *itemShownBelow = nullptr;
+
+    // We will iterate backwards because it's convenient to know beforehand if the item just below is its child or not.
+    for (int index = m_itemData.count() - 1; index >= 0; --index) {
+        ItemData *itemData = m_itemData.at(index);
+
+        if (m_filter.matches(itemData->item) || (itemShownBelow && itemShownBelow->parent == itemData)) {
+            // We could've entered here for two reasons:
+            // 1. This item passes the filter itself
+            // 2. This is an expanded folder that doesn't pass the filter but sees a filter-passing child just below
+
+            // So this item must remain shown.
+            // Lets register this item as the next shown item from the point of view of the next iteration of this for loop
+            itemShownBelow = itemData;
+        } else {
+            // We hide this item for now, however, for expanded folders this is not final:
+            // if after the next "for" loop we discover that its children must now be shown with the newly applied fliter, we shall re-insert it
+            newFilteredIndexes.prepend(index);
+            m_filteredItems.insert(itemData->item, itemData);
+            // indexShownBelow doesn't get updated since this item will be hidden
         }
     }
 
-    const KItemRangeList removedRanges = KItemRangeList::fromSortedContainer(newFilteredIndexes);
-    removeItems(removedRanges, KeepItemData);
+    // This will remove the newly filtered items from m_itemData
+    removeItems(KItemRangeList::fromSortedContainer(newFilteredIndexes), KeepItemData);
 
+    // ===STEP 2===
     // Check which hidden items from m_filteredItems should
-    // get visible again and hence removed from m_filteredItems.
-    QList<ItemData*> newVisibleItems;
+    // become visible again and hence moved from m_filteredItems back into m_itemData.
 
-    QHash<KFileItem, ItemData*>::iterator it = m_filteredItems.begin();
+    QList<ItemData *> newVisibleItems;
+
+    QHash<KFileItem, ItemData *> ancestorsOfNewVisibleItems; // We will make sure these also become visible in step 3.
+
+    QHash<KFileItem, ItemData *>::iterator it = m_filteredItems.begin();
     while (it != m_filteredItems.end()) {
         if (m_filter.matches(it.key())) {
             newVisibleItems.append(it.value());
+
+            // If this is a child of an expanded folder, we must make sure that its whole parental chain will also be shown.
+            // We will go up through its parental chain until we either:
+            // 1 - reach the "root item" of the current view, i.e the currently opened folder on Dolphin. Their children have their ItemData::parent set to
+            // nullptr. or 2 - we reach an unfiltered parent or a previously discovered ancestor.
+            for (ItemData *parent = it.value()->parent; parent && !ancestorsOfNewVisibleItems.contains(parent->item) && m_filteredItems.contains(parent->item);
+                 parent = parent->parent) {
+                // We wish we could remove this parent from m_filteredItems right now, but we are iterating over it
+                // and it would mess up the iteration. We will mark it to be removed in step 3.
+                ancestorsOfNewVisibleItems.insert(parent->item, parent);
+            }
+
             it = m_filteredItems.erase(it);
         } else {
+            // Item remains filtered for now
+            // However, for expanded folders this is not final, we may discover later that it has unfiltered descendants.
             ++it;
         }
     }
 
+    // ===STEP 3===
+    // Handles the ancestorsOfNewVisibleItems.
+    // Now that we are done iterating through m_filteredItems we can safely move the ancestorsOfNewVisibleItems from m_filteredItems to newVisibleItems.
+    for (it = ancestorsOfNewVisibleItems.begin(); it != ancestorsOfNewVisibleItems.end(); it++) {
+        if (m_filteredItems.remove(it.key())) {
+            // m_filteredItems still contained this ancestor until now so we can be sure that we aren't adding a duplicate ancestor to newVisibleItems.
+            newVisibleItems.append(it.value());
+        }
+    }
+
+    // This will insert the newly discovered unfiltered items into m_itemData
     insertItems(newVisibleItems);
 }
 
-void KFileItemModel::removeFilteredChildren(const KItemRangeList& itemRanges)
+void KFileItemModel::removeFilteredChildren(const KItemRangeList &itemRanges)
 {
     if (m_filteredItems.isEmpty() || !m_requestRole[ExpandedParentsCountRole]) {
         // There are either no filtered items, or it is not possible to expand
@@ -736,14 +905,14 @@ void KFileItemModel::removeFilteredChildren(const KItemRangeList& itemRanges)
         return;
     }
 
-    QSet<ItemData*> parents;
-    for (const KItemRange& range : itemRanges) {
+    QSet<ItemData *> parents;
+    for (const KItemRange &range : itemRanges) {
         for (int index = range.index; index < range.index + range.count; ++index) {
             parents.insert(m_itemData.at(index));
         }
     }
 
-    QHash<KFileItem, ItemData*>::iterator it = m_filteredItems.begin();
+    QHash<KFileItem, ItemData *>::iterator it = m_filteredItems.begin();
     while (it != m_filteredItems.end()) {
         if (parents.contains(it.value()->parent)) {
             delete it.value();
@@ -754,27 +923,48 @@ void KFileItemModel::removeFilteredChildren(const KItemRangeList& itemRanges)
     }
 }
 
+KFileItemModel::RoleInfo KFileItemModel::roleInformation(const QByteArray &role)
+{
+    static QHash<QByteArray, RoleInfo> information;
+    if (information.isEmpty()) {
+        int count = 0;
+        const RoleInfoMap *map = rolesInfoMap(count);
+        for (int i = 0; i < count; ++i) {
+            RoleInfo info;
+            info.role = map[i].role;
+            info.translation = map[i].roleTranslation.toString();
+            if (!map[i].groupTranslation.isEmpty()) {
+                info.group = map[i].groupTranslation.toString();
+            } else {
+                // For top level roles, groupTranslation is 0. We must make sure that
+                // info.group is an empty string then because the code that generates
+                // menus tries to put the actions into sub menus otherwise.
+                info.group = QString();
+            }
+            info.requiresBaloo = map[i].requiresBaloo;
+            info.requiresIndexer = map[i].requiresIndexer;
+            if (!map[i].tooltipTranslation.isEmpty()) {
+                info.tooltip = map[i].tooltipTranslation.toString();
+            } else {
+                info.tooltip = QString();
+            }
+
+            information.insert(map[i].role, info);
+        }
+    }
+
+    return information.value(role);
+}
+
 QList<KFileItemModel::RoleInfo> KFileItemModel::rolesInformation()
 {
     static QList<RoleInfo> rolesInfo;
     if (rolesInfo.isEmpty()) {
         int count = 0;
-        const RoleInfoMap* map = rolesInfoMap(count);
+        const RoleInfoMap *map = rolesInfoMap(count);
         for (int i = 0; i < count; ++i) {
             if (map[i].roleType != NoRole) {
-                RoleInfo info;
-                info.role = map[i].role;
-                info.translation = i18nc(map[i].roleTranslationContext, map[i].roleTranslation);
-                if (map[i].groupTranslation) {
-                    info.group = i18nc(map[i].groupTranslationContext, map[i].groupTranslation);
-                } else {
-                    // For top level roles, groupTranslation is 0. We must make sure that
-                    // info.group is an empty string then because the code that generates
-                    // menus tries to put the actions into sub menus otherwise.
-                    info.group = QString();
-                }
-                info.requiresBaloo = map[i].requiresBaloo;
-                info.requiresIndexer = map[i].requiresIndexer;
+                RoleInfo info = roleInformation(map[i].role);
                 rolesInfo.append(info);
             }
         }
@@ -783,16 +973,32 @@ QList<KFileItemModel::RoleInfo> KFileItemModel::rolesInformation()
     return rolesInfo;
 }
 
+QList<KFileItemModel::RoleInfo> KFileItemModel::extraGroupingInformation()
+{
+    static QList<RoleInfo> rolesInfo{
+        {QByteArray("none"),         kli18nc("@label", "No grouping").toString(),       nullptr,     nullptr,     false,      false},
+        {QByteArray("followSort"),   kli18nc("@label", "Follow sorting").toString(),    nullptr,    nullptr,     false,      false}
+    };
+    return rolesInfo;
+}
+
 void KFileItemModel::onGroupedSortingChanged(bool current)
 {
     Q_UNUSED(current)
     m_groups.clear();
 }
 
-void KFileItemModel::onSortRoleChanged(const QByteArray& current, const QByteArray& previous, bool resortItems)
+void KFileItemModel::onSortRoleChanged(const QByteArray &current, const QByteArray &previous, bool resortItems)
 {
     Q_UNUSED(previous)
     m_sortRole = typeForRole(current);
+    if (m_sortRole == NoRole) {
+        // Requested role not in list of roles. This could
+        // be used for indicating non-trivial sorting behavior
+        m_sortExtraInfo = current;
+    } else {
+        m_sortExtraInfo.clear();
+    }
 
     if (!m_requestRole[m_sortRole]) {
         QSet<QByteArray> newRoles = m_roles;
@@ -812,6 +1018,36 @@ void KFileItemModel::onSortOrderChanged(Qt::SortOrder current, Qt::SortOrder pre
     resortAllItems();
 }
 
+void KFileItemModel::onGroupRoleChanged(const QByteArray &current, const QByteArray &previous, bool resortItems)
+{
+    Q_UNUSED(previous)
+    m_groupRole = typeForRole(current);
+    if (m_groupRole == NoRole) {
+        // Requested role not in list of roles. This could
+        // be used for indicating non-trivial grouping behavior
+        m_groupExtraInfo = current;
+    } else {
+        m_groupExtraInfo.clear();
+    }
+
+    if (!m_requestRole[m_groupRole]) {
+        QSet<QByteArray> newRoles = m_roles;
+        newRoles << current;
+        setRoles(newRoles);
+    }
+
+    if (resortItems) {
+        resortAllItems();
+    }
+}
+
+void KFileItemModel::onGroupOrderChanged(Qt::SortOrder current, Qt::SortOrder previous)
+{
+    Q_UNUSED(current)
+    Q_UNUSED(previous)
+    resortAllItems();
+}
+
 void KFileItemModel::loadSortingSettings()
 {
     using Choice = GeneralSettings::EnumSortingChoice;
@@ -834,6 +1070,7 @@ void KFileItemModel::loadSortingSettings()
     // Workaround for bug https://bugreports.qt.io/browse/QTBUG-69361
     // Force the clean state of QCollator in single thread to avoid thread safety problems in sort
     m_collator.compare(QString(), QString());
+    ContentDisplaySettings::self();
 }
 
 void KFileItemModel::resortAllItems()
@@ -857,7 +1094,7 @@ void KFileItemModel::resortAllItems()
     // been moved because of the resorting.
     QList<QUrl> oldUrls;
     oldUrls.reserve(itemCount);
-    for (const ItemData* itemData : qAsConst(m_itemData)) {
+    for (const ItemData *itemData : std::as_const(m_itemData)) {
         oldUrls.append(itemData->item.url());
     }
 
@@ -872,8 +1109,7 @@ void KFileItemModel::resortAllItems()
 
     // Determine the first index that has been moved.
     int firstMovedIndex = 0;
-    while (firstMovedIndex < itemCount
-           && firstMovedIndex == m_items.value(oldUrls.at(firstMovedIndex))) {
+    while (firstMovedIndex < itemCount && firstMovedIndex == m_items.value(oldUrls.at(firstMovedIndex))) {
         ++firstMovedIndex;
     }
 
@@ -882,8 +1118,7 @@ void KFileItemModel::resortAllItems()
         m_groups.clear();
 
         int lastMovedIndex = itemCount - 1;
-        while (lastMovedIndex > firstMovedIndex
-               && lastMovedIndex == m_items.value(oldUrls.at(lastMovedIndex))) {
+        while (lastMovedIndex > firstMovedIndex && lastMovedIndex == m_items.value(oldUrls.at(lastMovedIndex))) {
             --lastMovedIndex;
         }
 
@@ -901,9 +1136,10 @@ void KFileItemModel::resortAllItems()
         }
 
         Q_EMIT itemsMoved(KItemRange(firstMovedIndex, movedItemsCount), movedToIndexes);
-    } else if (groupedSorting()) {
+    }
+    if (groupedSorting()) {
         // The groups might have changed even if the order of the items has not.
-        const QList<QPair<int, QVariant> > oldGroups = m_groups;
+        const QList<QPair<int, QVariant>> oldGroups = m_groups;
         m_groups.clear();
         if (groups() != oldGroups) {
             Q_EMIT groupsChanged();
@@ -927,7 +1163,7 @@ void KFileItemModel::slotCompleted()
         // -> we expand the first visible URL we find in m_restoredExpandedUrls.
         // Iterate over a const copy because items are deleted and inserted within the loop
         const auto urlsToExpand = m_urlsToExpand;
-        for(const QUrl &url : urlsToExpand) {
+        for (const QUrl &url : urlsToExpand) {
             const int indexForUrl = index(url);
             if (indexForUrl >= 0) {
                 m_urlsToExpand.remove(url);
@@ -955,16 +1191,11 @@ void KFileItemModel::slotCanceled()
     Q_EMIT directoryLoadingCanceled();
 }
 
-void KFileItemModel::slotItemsAdded(const QUrl &directoryUrl, const KFileItemList& items)
+void KFileItemModel::slotItemsAdded(const QUrl &directoryUrl, const KFileItemList &items)
 {
     Q_ASSERT(!items.isEmpty());
 
-    QUrl parentUrl;
-    if (m_expandedDirs.contains(directoryUrl)) {
-        parentUrl = m_expandedDirs.value(directoryUrl);
-    } else {
-        parentUrl = directoryUrl.adjusted(QUrl::StripTrailingSlash);
-    }
+    const QUrl parentUrl = m_expandedDirs.value(directoryUrl, directoryUrl.adjusted(QUrl::StripTrailingSlash));
 
     if (m_requestRole[ExpandedParentsCountRole]) {
         // If the expanding of items is enabled, the call
@@ -993,21 +1224,33 @@ void KFileItemModel::slotItemsAdded(const QUrl &directoryUrl, const KFileItemLis
         }
     }
 
-    const QList<ItemData*> itemDataList = createItemDataList(parentUrl, items);
+    const QList<ItemData *> itemDataList = createItemDataList(parentUrl, items);
 
     if (!m_filter.hasSetFilters()) {
         m_pendingItemsToInsert.append(itemDataList);
     } else {
+        QSet<ItemData *> parentsToEnsureVisible;
+
         // The name or type filter is active. Hide filtered items
         // before inserting them into the model and remember
         // the filtered items in m_filteredItems.
-        for (ItemData* itemData : itemDataList) {
+        for (ItemData *itemData : itemDataList) {
             if (m_filter.matches(itemData->item)) {
                 m_pendingItemsToInsert.append(itemData);
+                if (itemData->parent) {
+                    parentsToEnsureVisible.insert(itemData->parent);
+                }
             } else {
                 m_filteredItems.insert(itemData->item, itemData);
             }
         }
+
+        // Entire parental chains must be shown
+        for (ItemData *parent : parentsToEnsureVisible) {
+            for (; parent && m_filteredItems.remove(parent->item); parent = parent->parent) {
+                m_pendingItemsToInsert.append(parent);
+            }
+        }
     }
 
     if (!m_maximumUpdateIntervalTimer->isActive()) {
@@ -1015,27 +1258,78 @@ void KFileItemModel::slotItemsAdded(const QUrl &directoryUrl, const KFileItemLis
         // emitted during the maximum update interval.
         m_maximumUpdateIntervalTimer->start();
     }
+
+    Q_EMIT fileItemsChanged({KFileItem(directoryUrl)});
+}
+
+int KFileItemModel::filterChildlessParents(KItemRangeList &removedItemRanges, const QSet<ItemData *> &parentsToEnsureVisible)
+{
+    int filteredParentsCount = 0;
+    // The childless parents not yet removed will always be right above the start of a removed range.
+    // We iterate backwards to ensure the deepest folders are processed before their parents
+    for (int i = removedItemRanges.size() - 1; i >= 0; i--) {
+        KItemRange itemRange = removedItemRanges.at(i);
+        const ItemData *const firstInRange = m_itemData.at(itemRange.index);
+        ItemData *itemAbove = itemRange.index - 1 >= 0 ? m_itemData.at(itemRange.index - 1) : nullptr;
+        const ItemData *const itemBelow = itemRange.index + itemRange.count < m_itemData.count() ? m_itemData.at(itemRange.index + itemRange.count) : nullptr;
+
+        if (itemAbove && firstInRange->parent == itemAbove && !m_filter.matches(itemAbove->item) && (!itemBelow || itemBelow->parent != itemAbove)
+            && !parentsToEnsureVisible.contains(itemAbove)) {
+            // The item above exists, is the parent, doesn't pass the filter, does not belong to parentsToEnsureVisible
+            // and this deleted range covers all of its descendents, so none will be left.
+            m_filteredItems.insert(itemAbove->item, itemAbove);
+            // This range's starting index will be extended to include the parent above:
+            --itemRange.index;
+            ++itemRange.count;
+            ++filteredParentsCount;
+            KItemRange previousRange = i > 0 ? removedItemRanges.at(i - 1) : KItemRange();
+            // We must check if this caused the range to touch the previous range, if that's the case they shall be merged
+            if (i > 0 && previousRange.index + previousRange.count == itemRange.index) {
+                previousRange.count += itemRange.count;
+                removedItemRanges.replace(i - 1, previousRange);
+                removedItemRanges.removeAt(i);
+            } else {
+                removedItemRanges.replace(i, itemRange);
+                // We must revisit this range in the next iteration since its starting index changed
+                ++i;
+            }
+        }
+    }
+    return filteredParentsCount;
 }
 
-void KFileItemModel::slotItemsDeleted(const KFileItemList& items)
+void KFileItemModel::slotItemsDeleted(const KFileItemList &items)
 {
     dispatchPendingItemsToInsert();
 
     QVector<int> indexesToRemove;
     indexesToRemove.reserve(items.count());
+    KFileItemList dirsChanged;
+
+    const auto currentDir = directory();
+
+    for (const KFileItem &item : items) {
+        if (item.url() == currentDir) {
+            Q_EMIT currentDirectoryRemoved();
+            return;
+        }
 
-    for (const KFileItem& item : items) {
         const int indexForItem = index(item);
         if (indexForItem >= 0) {
             indexesToRemove.append(indexForItem);
         } else {
             // Probably the item has been filtered.
-            QHash<KFileItem, ItemData*>::iterator it = m_filteredItems.find(item);
+            QHash<KFileItem, ItemData *>::iterator it = m_filteredItems.find(item);
             if (it != m_filteredItems.end()) {
                 delete it.value();
                 m_filteredItems.erase(it);
             }
         }
+
+        QUrl parentUrl = item.url().adjusted(QUrl::RemoveFilename | QUrl::StripTrailingSlash);
+        if (dirsChanged.findByUrl(parentUrl).isNull()) {
+            dirsChanged << KFileItem(parentUrl);
+        }
     }
 
     std::sort(indexesToRemove.begin(), indexesToRemove.end());
@@ -1046,7 +1340,7 @@ void KFileItemModel::slotItemsDeleted(const KFileItemList& items)
         indexesToRemoveWithChildren.reserve(m_itemData.count());
 
         const int itemCount = m_itemData.count();
-        for (int index : qAsConst(indexesToRemove)) {
+        for (int index : std::as_const(indexesToRemove)) {
             indexesToRemoveWithChildren.append(index);
 
             const int parentLevel = expandedParentsCount(index);
@@ -1060,12 +1354,22 @@ void KFileItemModel::slotItemsDeleted(const KFileItemList& items)
         indexesToRemove = indexesToRemoveWithChildren;
     }
 
-    const KItemRangeList itemRanges = KItemRangeList::fromSortedContainer(indexesToRemove);
+    KItemRangeList itemRanges = KItemRangeList::fromSortedContainer(indexesToRemove);
     removeFilteredChildren(itemRanges);
-    removeItems(itemRanges, DeleteItemData);
+
+    // This call will update itemRanges to include the childless parents that have been filtered.
+    const int filteredParentsCount = filterChildlessParents(itemRanges);
+
+    // If any childless parents were filtered, then itemRanges got updated and now contains items that were really deleted
+    // mixed with expanded folders that are just being filtered out.
+    // If that's the case, we pass 'DeleteItemDataIfUnfiltered' as a hint
+    // so removeItems() will check m_filteredItems to differentiate which is which.
+    removeItems(itemRanges, filteredParentsCount > 0 ? DeleteItemDataIfUnfiltered : DeleteItemData);
+
+    Q_EMIT fileItemsChanged(dirsChanged);
 }
 
-void KFileItemModel::slotRefreshItems(const QList<QPair<KFileItem, KFileItem> >& items)
+void KFileItemModel::slotRefreshItems(const QList<QPair<KFileItem, KFileItem>> &items)
 {
     Q_ASSERT(!items.isEmpty());
 #ifdef KFILEITEMMODEL_DEBUG
@@ -1077,59 +1381,151 @@ void KFileItemModel::slotRefreshItems(const QList<QPair<KFileItem, KFileItem> >&
     indexes.reserve(items.count());
 
     QSet<QByteArray> changedRoles;
+    KFileItemList changedFiles;
+
+    // Contains the indexes of the currently visible items
+    // that should get hidden and hence moved to m_filteredItems.
+    QVector<int> newFilteredIndexes;
+
+    // Contains currently hidden items that should
+    // get visible and hence removed from m_filteredItems
+    QList<ItemData *> newVisibleItems;
+
+    QListIterator<QPair<KFileItem, KFileItem>> it(items);
 
-    QListIterator<QPair<KFileItem, KFileItem> > it(items);
     while (it.hasNext()) {
-        const QPair<KFileItem, KFileItem>& itemPair = it.next();
-        const KFileItem& oldItem = itemPair.first;
-        const KFileItem& newItem = itemPair.second;
+        const QPair<KFileItem, KFileItem> &itemPair = it.next();
+        const KFileItem &oldItem = itemPair.first;
+        const KFileItem &newItem = itemPair.second;
         const int indexForItem = index(oldItem);
+        const bool newItemMatchesFilter = m_filter.matches(newItem);
         if (indexForItem >= 0) {
             m_itemData[indexForItem]->item = newItem;
 
             // Keep old values as long as possible if they could not retrieved synchronously yet.
             // The update of the values will be done asynchronously by KFileItemModelRolesUpdater.
-            QHashIterator<QByteArray, QVariant> it(retrieveData(newItem, m_itemData.at(indexForItem)->parent));
-            QHash<QByteArray, QVariant>& values = m_itemData[indexForItem]->values;
+            ItemData *const itemData = m_itemData.at(indexForItem);
+            QHashIterator<QByteArray, QVariant> it(retrieveData(newItem, itemData->parent));
             while (it.hasNext()) {
                 it.next();
-                const QByteArray& role = it.key();
-                if (values.value(role) != it.value()) {
-                    values.insert(role, it.value());
+                const QByteArray &role = it.key();
+                if (itemData->values.value(role) != it.value()) {
+                    itemData->values.insert(role, it.value());
                     changedRoles.insert(role);
                 }
             }
 
             m_items.remove(oldItem.url());
+            // We must maintain m_items consistent with m_itemData for now, this very loop is using it.
+            // We leave it to be cleared by removeItems() later, when m_itemData actually gets updated.
             m_items.insert(newItem.url(), indexForItem);
-            indexes.append(indexForItem);
+            if (newItemMatchesFilter
+                || (itemData->values.value("isExpanded").toBool()
+                    && (indexForItem + 1 < m_itemData.count() && m_itemData.at(indexForItem + 1)->parent == itemData))) {
+                // We are lenient with expanded folders that originally had visible children.
+                // If they become childless now they will be caught by filterChildlessParents()
+                changedFiles.append(newItem);
+                indexes.append(indexForItem);
+            } else {
+                newFilteredIndexes.append(indexForItem);
+                m_filteredItems.insert(newItem, itemData);
+            }
         } else {
             // Check if 'oldItem' is one of the filtered items.
-            QHash<KFileItem, ItemData*>::iterator it = m_filteredItems.find(oldItem);
+            QHash<KFileItem, ItemData *>::iterator it = m_filteredItems.find(oldItem);
             if (it != m_filteredItems.end()) {
-                ItemData* itemData = it.value();
+                ItemData *const itemData = it.value();
                 itemData->item = newItem;
 
                 // The data stored in 'values' might have changed. Therefore, we clear
                 // 'values' and re-populate it the next time it is requested via data(int).
+                // Before clearing, we must remember if it was expanded and the expanded parents count,
+                // otherwise these states would be lost. The data() method will deal with this special case.
+                const bool isExpanded = itemData->values.value("isExpanded").toBool();
+                bool hasExpandedParentsCount = false;
+                const int expandedParentsCount = itemData->values.value("expandedParentsCount").toInt(&hasExpandedParentsCount);
                 itemData->values.clear();
+                if (isExpanded) {
+                    itemData->values.insert("isExpanded", true);
+                    if (hasExpandedParentsCount) {
+                        itemData->values.insert("expandedParentsCount", expandedParentsCount);
+                    }
+                }
 
                 m_filteredItems.erase(it);
-                m_filteredItems.insert(newItem, itemData);
+                if (newItemMatchesFilter) {
+                    newVisibleItems.append(itemData);
+                } else {
+                    m_filteredItems.insert(newItem, itemData);
+                }
+            }
+        }
+    }
+
+    std::sort(newFilteredIndexes.begin(), newFilteredIndexes.end());
+
+    // We must keep track of parents of new visible items since they must be shown no matter what
+    // They will be considered "immune" to filterChildlessParents()
+    QSet<ItemData *> parentsToEnsureVisible;
+
+    for (ItemData *item : newVisibleItems) {
+        for (ItemData *parent = item->parent; parent && !parentsToEnsureVisible.contains(parent); parent = parent->parent) {
+            parentsToEnsureVisible.insert(parent);
+        }
+    }
+    for (ItemData *parent : parentsToEnsureVisible) {
+        // We make sure they are all unfiltered.
+        if (m_filteredItems.remove(parent->item)) {
+            // If it is being unfiltered now, we mark it to be inserted by appending it to newVisibleItems
+            newVisibleItems.append(parent);
+            // It could be in newFilteredIndexes, we must remove it if it's there:
+            const int parentIndex = index(parent->item);
+            if (parentIndex >= 0) {
+                QVector<int>::iterator it = std::lower_bound(newFilteredIndexes.begin(), newFilteredIndexes.end(), parentIndex);
+                if (it != newFilteredIndexes.end() && *it == parentIndex) {
+                    newFilteredIndexes.erase(it);
+                }
             }
         }
     }
 
+    KItemRangeList removedRanges = KItemRangeList::fromSortedContainer(newFilteredIndexes);
+
+    // This call will update itemRanges to include the childless parents that have been filtered.
+    filterChildlessParents(removedRanges, parentsToEnsureVisible);
+
+    removeItems(removedRanges, KeepItemData);
+
+    // Show previously hidden items that should get visible
+    insertItems(newVisibleItems);
+
+    // Final step: we will emit 'itemsChanged' and 'fileItemsChanged' signals and trigger the asynchronous re-sorting logic.
+
     // If the changed items have been created recently, they might not be in m_items yet.
     // In that case, the list 'indexes' might be empty.
     if (indexes.isEmpty()) {
         return;
     }
 
+    if (newVisibleItems.count() > 0 || removedRanges.count() > 0) {
+        // The original indexes have changed and are now worthless since items were removed and/or inserted.
+        indexes.clear();
+        // m_items is not yet rebuilt at this point, so we use our own means to resolve the new indexes.
+        const QSet<const KFileItem> changedFilesSet(changedFiles.cbegin(), changedFiles.cend());
+        for (int i = 0; i < m_itemData.count(); i++) {
+            if (changedFilesSet.contains(m_itemData.at(i)->item)) {
+                indexes.append(i);
+            }
+        }
+    } else {
+        std::sort(indexes.begin(), indexes.end());
+    }
+
     // Extract the item-ranges out of the changed indexes
-    std::sort(indexes.begin(), indexes.end());
     const KItemRangeList itemRangeList = KItemRangeList::fromSortedContainer(indexes);
     emitItemsChangedAndTriggerResorting(itemRangeList, changedRoles);
+
+    Q_EMIT fileItemsChanged(changedFiles);
 }
 
 void KFileItemModel::slotClear()
@@ -1173,7 +1569,7 @@ void KFileItemModel::dispatchPendingItemsToInsert()
     }
 }
 
-void KFileItemModel::insertItems(QList<ItemData*>& newItems)
+void KFileItemModel::insertItems(QList<ItemData *> &newItems)
 {
     if (newItems.isEmpty()) {
         return;
@@ -1196,8 +1592,7 @@ void KFileItemModel::insertItems(QList<ItemData*>& newItems)
         if (m_sortRole == NameRole) {
             parallelMergeSort(newItems.begin(), newItems.end(), nameLessThan, QThread::idealThreadCount());
         } else if (isRoleValueNatural(m_sortRole)) {
-            auto lambdaLessThan = [&] (const KFileItemModel::ItemData* a, const KFileItemModel::ItemData* b)
-            {
+            auto lambdaLessThan = [&](const KFileItemModel::ItemData *a, const KFileItemModel::ItemData *b) {
                 const QByteArray role = roleForType(m_sortRole);
                 return a->values.value(role).toString() < b->values.value(role).toString();
             };
@@ -1236,7 +1631,7 @@ void KFileItemModel::insertItems(QList<ItemData*>& newItems)
         int rangeCount = 0;
 
         while (sourceIndexNewItems >= 0) {
-            ItemData* newItem = newItems.at(sourceIndexNewItems);
+            ItemData *newItem = newItems.at(sourceIndexNewItems);
             if (sourceIndexExistingItems >= 0 && lessThan(newItem, m_itemData.at(sourceIndexExistingItems), m_collator)) {
                 // Move an existing item to its new position. If any new items
                 // are behind it, push the item range to itemRanges.
@@ -1276,7 +1671,7 @@ void KFileItemModel::insertItems(QList<ItemData*>& newItems)
 #endif
 }
 
-void KFileItemModel::removeItems(const KItemRangeList& itemRanges, RemoveItemsBehavior behavior)
+void KFileItemModel::removeItems(const KItemRangeList &itemRanges, RemoveItemsBehavior behavior)
 {
     if (itemRanges.isEmpty()) {
         return;
@@ -1286,11 +1681,11 @@ void KFileItemModel::removeItems(const KItemRangeList& itemRanges, RemoveItemsBe
 
     // Step 1: Remove the items from m_itemData, and free the ItemData.
     int removedItemsCount = 0;
-    for (const KItemRange& range : itemRanges) {
+    for (const KItemRange &range : itemRanges) {
         removedItemsCount += range.count;
 
         for (int index = range.index; index < range.index + range.count; ++index) {
-            if (behavior == DeleteItemData) {
+            if (behavior == DeleteItemData || (behavior == DeleteItemDataIfUnfiltered && !m_filteredItems.contains(m_itemData.at(index)->item))) {
                 delete m_itemData.at(index);
             }
 
@@ -1325,23 +1720,24 @@ void KFileItemModel::removeItems(const KItemRangeList& itemRanges, RemoveItemsBe
     Q_EMIT itemsRemoved(itemRanges);
 }
 
-QList<KFileItemModel::ItemData*> KFileItemModel::createItemDataList(const QUrl& parentUrl, const KFileItemList& items) const
+QList<KFileItemModel::ItemData *> KFileItemModel::createItemDataList(const QUrl &parentUrl, const KFileItemList &items) const
 {
-    if (m_sortRole == TypeRole) {
+    if (m_sortRole == TypeRole || m_groupRole == TypeRole) {
         // Try to resolve the MIME-types synchronously to prevent a reordering of
         // the items when sorting by type (per default MIME-types are resolved
         // asynchronously by KFileItemModelRolesUpdater).
         determineMimeTypes(items, 200);
     }
 
+    // We search for the parent in m_itemData and then in m_filteredItems if necessary
     const int parentIndex = index(parentUrl);
-    ItemData* parentItem = parentIndex < 0 ? nullptr : m_itemData.at(parentIndex);
+    ItemData *parentItem = parentIndex < 0 ? m_filteredItems.value(KFileItem(parentUrl), nullptr) : m_itemData.at(parentIndex);
 
-    QList<ItemData*> itemDataList;
+    QList<ItemData *> itemDataList;
     itemDataList.reserve(items.count());
 
-    for (const KFileItem& item : items) {
-        ItemData* itemData = new ItemData();
+    for (const KFileItem &item : items) {
+        ItemData *itemData = new ItemData();
         itemData->item = item;
         itemData->parent = parentItem;
         itemDataList.append(itemData);
@@ -1350,9 +1746,10 @@ QList<KFileItemModel::ItemData*> KFileItemModel::createItemDataList(const QUrl&
     return itemDataList;
 }
 
-void KFileItemModel::prepareItemsForSorting(QList<ItemData*>& itemDataList)
+void KFileItemModel::prepareItemsWithRole(QList<ItemData *> &itemDataList, RoleType roleType)
 {
-    switch (m_sortRole) {
+    switch (roleType) {
+    case ExtensionRole:
     case PermissionsRole:
     case OwnerRole:
     case GroupRole:
@@ -1361,7 +1758,7 @@ void KFileItemModel::prepareItemsForSorting(QList<ItemData*>& itemDataList)
     case DeletionTimeRole:
         // These roles can be determined with retrieveData, and they have to be stored
         // in the QHash "values" for the sorting.
-        for (ItemData* itemData : qAsConst(itemDataList)) {
+        for (ItemData *itemData : std::as_const(itemDataList)) {
             if (itemData->values.isEmpty()) {
                 itemData->values = retrieveData(itemData->item, itemData->parent);
             }
@@ -1370,7 +1767,7 @@ void KFileItemModel::prepareItemsForSorting(QList<ItemData*>& itemDataList)
 
     case TypeRole:
         // At least store the data including the file type for items with known MIME type.
-        for (ItemData* itemData : qAsConst(itemDataList)) {
+        for (ItemData *itemData : std::as_const(itemDataList)) {
             if (itemData->values.isEmpty()) {
                 const KFileItem item = itemData->item;
                 if (item.isDir() || item.isMimeTypeKnown()) {
@@ -1390,11 +1787,17 @@ void KFileItemModel::prepareItemsForSorting(QList<ItemData*>& itemDataList)
     }
 }
 
-int KFileItemModel::expandedParentsCount(const ItemData* data)
+void KFileItemModel::prepareItemsForSorting(QList<ItemData *> &itemDataList)
+{
+    prepareItemsWithRole(itemDataList, m_sortRole);
+    prepareItemsWithRole(itemDataList, m_groupRole);
+}
+
+int KFileItemModel::expandedParentsCount(const ItemData *data)
 {
     // The hash 'values' is only guaranteed to contain the key "expandedParentsCount"
     // if the corresponding item is expanded, and it is not a top-level item.
-    const ItemData* parent = data->parent;
+    const ItemData *parent = data->parent;
     if (parent) {
         if (parent->parent) {
             Q_ASSERT(parent->values.contains("expandedParentsCount"));
@@ -1413,7 +1816,7 @@ void KFileItemModel::removeExpandedItems()
 
     const int maxIndex = m_itemData.count() - 1;
     for (int i = 0; i <= maxIndex; ++i) {
-        const ItemData* itemData = m_itemData.at(i);
+        const ItemData *itemData = m_itemData.at(i);
         if (itemData->parent) {
             indexesToRemove.append(i);
         }
@@ -1423,8 +1826,8 @@ void KFileItemModel::removeExpandedItems()
     m_expandedDirs.clear();
 
     // Also remove all filtered items which have a parent.
-    QHash<KFileItem, ItemData*>::iterator it = m_filteredItems.begin();
-    const QHash<KFileItem, ItemData*>::iterator end = m_filteredItems.end();
+    QHash<KFileItem, ItemData *>::iterator it = m_filteredItems.begin();
+    const QHash<KFileItem, ItemData *>::iterator end = m_filteredItems.end();
 
     while (it != end) {
         if (it.value()->parent) {
@@ -1436,14 +1839,15 @@ void KFileItemModel::removeExpandedItems()
     }
 }
 
-void KFileItemModel::emitItemsChangedAndTriggerResorting(const KItemRangeList& itemRanges, const QSet<QByteArray>& changedRoles)
+void KFileItemModel::emitItemsChangedAndTriggerResorting(const KItemRangeList &itemRanges, const QSet<QByteArray> &changedRoles)
 {
     Q_EMIT itemsChanged(itemRanges, changedRoles);
 
     // Trigger a resorting if necessary. Note that this can happen even if the sort
     // role has not changed at all because the file name can be used as a fallback.
-    if (changedRoles.contains(sortRole()) || changedRoles.contains(roleForType(NameRole))) {
-        for (const KItemRange& range : itemRanges) {
+    if (changedRoles.contains(sortRole()) || changedRoles.contains(roleForType(NameRole))
+        || (changedRoles.contains("count") && sortRole() == "size")) { // "count" is used in the "size" sort role, so this might require a resorting.
+        for (const KItemRange &range : itemRanges) {
             bool needsResorting = false;
 
             const int first = range.index;
@@ -1453,11 +1857,9 @@ void KFileItemModel::emitItemsChangedAndTriggerResorting(const KItemRangeList& i
             // (a)  The first item in the range is "lessThan" its predecessor,
             // (b)  the successor of the last item is "lessThan" the last item, or
             // (c)  the internal order of the items in the range is incorrect.
-            if (first > 0
-                && lessThan(m_itemData.at(first), m_itemData.at(first - 1), m_collator)) {
+            if (first > 0 && lessThan(m_itemData.at(first), m_itemData.at(first - 1), m_collator)) {
                 needsResorting = true;
-            } else if (last < count() - 1
-                && lessThan(m_itemData.at(last + 1), m_itemData.at(last), m_collator)) {
+            } else if (last < count() - 1 && lessThan(m_itemData.at(last + 1), m_itemData.at(last), m_collator)) {
                 needsResorting = true;
             } else {
                 for (int index = first; index < last; ++index) {
@@ -1469,7 +1871,7 @@ void KFileItemModel::emitItemsChangedAndTriggerResorting(const KItemRangeList& i
             }
 
             if (needsResorting) {
-                m_resortAllItemsTimer->start();
+                scheduleResortAllItems();
                 return;
             }
         }
@@ -1495,14 +1897,14 @@ void KFileItemModel::resetRoles()
     }
 }
 
-KFileItemModel::RoleType KFileItemModel::typeForRole(const QByteArray& role) const
+KFileItemModel::RoleType KFileItemModel::typeForRole(const QByteArray &role) const
 {
     static QHash<QByteArray, RoleType> roles;
     if (roles.isEmpty()) {
         // Insert user visible roles that can be accessed with
         // KFileItemModel::roleInformation()
         int count = 0;
-        const RoleInfoMap* map = rolesInfoMap(count);
+        const RoleInfoMap *map = rolesInfoMap(count);
         for (int i = 0; i < count; ++i) {
             roles.insert(map[i].role, map[i].roleType);
         }
@@ -1529,7 +1931,7 @@ QByteArray KFileItemModel::roleForType(RoleType roleType) const
         // Insert user visible roles that can be accessed with
         // KFileItemModel::roleInformation()
         int count = 0;
-        const RoleInfoMap* map = rolesInfoMap(count);
+        const RoleInfoMap *map = rolesInfoMap(count);
         for (int i = 0; i < count; ++i) {
             roles.insert(map[i].roleType, map[i].role);
         }
@@ -1549,7 +1951,7 @@ QByteArray KFileItemModel::roleForType(RoleType roleType) const
     return roles.value(roleType);
 }
 
-QHash<QByteArray, QVariant> KFileItemModel::retrieveData(const KFileItem& item, const ItemData* parent) const
+QHash<QByteArray, QVariant> KFileItemModel::retrieveData(const KFileItem &item, const ItemData *parent) const
 {
     // It is important to insert only roles that are fast to retrieve. E.g.
     // KFileItem::iconName() can be very expensive if the MIME-type is unknown
@@ -1567,13 +1969,18 @@ QHash<QByteArray, QVariant> KFileItemModel::retrieveData(const KFileItem& item,
     }
 
     if (m_requestRole[IsHiddenRole]) {
-        data.insert(sharedValue("isHidden"), item.isHidden());
+        data.insert(sharedValue("isHidden"), item.isHidden() || item.mimetype() == QStringLiteral("application/x-trash"));
     }
 
     if (m_requestRole[NameRole]) {
         data.insert(sharedValue("text"), item.text());
     }
 
+    if (m_requestRole[ExtensionRole] && !isDir) {
+        // TODO KF6 use KFileItem::suffix 464722
+        data.insert(sharedValue("extension"), QFileInfo(item.name()).suffix());
+    }
+
     if (m_requestRole[SizeRole] && !isDir) {
         data.insert(sharedValue("size"), item.size());
     }
@@ -1603,7 +2010,7 @@ QHash<QByteArray, QVariant> KFileItemModel::retrieveData(const KFileItem& item,
     }
 
     if (m_requestRole[PermissionsRole]) {
-        data.insert(sharedValue("permissions"), item.permissionsString());
+        data.insert(sharedValue("permissions"), QVariantList() << item.permissionsString() << item.permissions());
     }
 
     if (m_requestRole[OwnerRole]) {
@@ -1684,7 +2091,7 @@ QHash<QByteArray, QVariant> KFileItemModel::retrieveData(const KFileItem& item,
     return data;
 }
 
-bool KFileItemModel::lessThan(const ItemData* a, const ItemData* b, const QCollator& collator) const
+bool KFileItemModel::lessThan(const ItemData *a, const ItemData *b, const QCollator &collator) const
 {
     int result = 0;
 
@@ -1719,26 +2126,38 @@ bool KFileItemModel::lessThan(const ItemData* a, const ItemData* b, const QColla
         }
     }
 
-    if (m_sortDirsFirst || m_sortRole == SizeRole) {
-        const bool isDirA = a->item.isDir();
-        const bool isDirB = b->item.isDir();
-        if (isDirA && !isDirB) {
-            return true;
-        } else if (!isDirA && isDirB) {
-            return false;
+    result = groupRoleCompare(a, b, collator);
+    if (result == 0) {
+        // Show hidden files and folders last
+        if (m_sortHiddenLast) {
+            const bool isHiddenA = a->item.isHidden();
+            const bool isHiddenB = b->item.isHidden();
+            if (isHiddenA && !isHiddenB) {
+                return false;
+            } else if (!isHiddenA && isHiddenB) {
+                return true;
+            }
         }
+        if (m_sortDirsFirst || (ContentDisplaySettings::directorySizeMode() == ContentDisplaySettings::EnumDirectorySizeMode::ContentCount && m_sortRole == SizeRole)) {
+            const bool isDirA = a->item.isDir();
+            const bool isDirB = b->item.isDir();
+            if (isDirA && !isDirB) {
+                return true;
+            } else if (!isDirA && isDirB) {
+                return false;
+            }
+        }
+        result = sortRoleCompare(a, b, collator);
+        result = (sortOrder() == Qt::AscendingOrder) ? result < 0 : result > 0;
+    } else {
+        result = (groupOrder() == Qt::AscendingOrder) ? result < 0 : result > 0;
     }
-
-    result = sortRoleCompare(a, b, collator);
-
-    return (sortOrder() == Qt::AscendingOrder) ? result < 0 : result > 0;
+    return result;
 }
 
-void KFileItemModel::sort(const QList<KFileItemModel::ItemData*>::iterator &begin,
-                          const QList<KFileItemModel::ItemData*>::iterator &end) const
+void KFileItemModel::sort(const QList<KFileItemModel::ItemData *>::iterator &begin, const QList<KFileItemModel::ItemData *>::iterator &end) const
 {
-    auto lambdaLessThan = [&] (const KFileItemModel::ItemData* a, const KFileItemModel::ItemData* b)
-    {
+    auto lambdaLessThan = [&](const KFileItemModel::ItemData *a, const KFileItemModel::ItemData *b) {
         return lessThan(a, b, m_collator);
     };
 
@@ -1755,10 +2174,15 @@ void KFileItemModel::sort(const QList<KFileItemModel::ItemData*>::iterator &begi
     }
 }
 
-int KFileItemModel::sortRoleCompare(const ItemData* a, const ItemData* b, const QCollator& collator) const
+int KFileItemModel::sortRoleCompare(const ItemData *a, const ItemData *b, const QCollator &collator) const
 {
-    const KFileItem& itemA = a->item;
-    const KFileItem& itemB = b->item;
+    // This function must never return 0, because that would break stable
+    // sorting, which leads to all kinds of bugs.
+    // See: https://bugs.kde.org/show_bug.cgi?id=433247
+    // If two items have equal sort values, let the fallbacks at the bottom of
+    // the function handle it.
+    const KFileItem &itemA = a->item;
+    const KFileItem &itemB = b->item;
 
     int result = 0;
 
@@ -1768,44 +2192,43 @@ int KFileItemModel::sortRoleCompare(const ItemData* a, const ItemData* b, const
         break;
 
     case SizeRole: {
-        if (itemA.isDir()) {
-            // See "if (m_sortFoldersFirst || m_sortRole == SizeRole)" in KFileItemModel::lessThan():
-            Q_ASSERT(itemB.isDir());
-
-            QVariant valueA, valueB;
-            if (DetailsModeSettings::directorySizeCount()) {
-                valueA = a->values.value("count");
-                valueB = b->values.value("count");
-            } else {
-                // use dir size then
-                valueA = a->values.value("size");
-                valueB = b->values.value("size");
-            }
-            if (valueA.isNull() && valueB.isNull()) {
-                result = 0;
-            } else if (valueA.isNull()) {
-                result = -1;
+        if (ContentDisplaySettings::directorySizeMode() == ContentDisplaySettings::EnumDirectorySizeMode::ContentCount && itemA.isDir()) {
+            // folders first then
+            // items A and B are folders thanks to lessThan checks
+            auto valueA = a->values.value("count");
+            auto valueB = b->values.value("count");
+            if (valueA.isNull()) {
+                if (!valueB.isNull()) {
+                    return -1;
+                }
             } else if (valueB.isNull()) {
-                result = +1;
+                return +1;
             } else {
                 if (valueA.toLongLong() < valueB.toLongLong()) {
                     return -1;
-                } else {
+                } else if (valueA.toLongLong() > valueB.toLongLong()) {
                     return +1;
                 }
             }
+            break;
+        }
+
+        KIO::filesize_t sizeA = 0;
+        if (itemA.isDir()) {
+            sizeA = a->values.value("size").toULongLong();
         } else {
-            // See "if (m_sortFoldersFirst || m_sortRole == SizeRole)" in KFileItemModel::lessThan():
-            Q_ASSERT(!itemB.isDir());
-            const KIO::filesize_t sizeA = itemA.size();
-            const KIO::filesize_t sizeB = itemB.size();
-            if (sizeA > sizeB) {
-                result = +1;
-            } else if (sizeA < sizeB) {
-                result = -1;
-            } else {
-                result = 0;
-            }
+            sizeA = itemA.size();
+        }
+        KIO::filesize_t sizeB = 0;
+        if (itemB.isDir()) {
+            sizeB = b->values.value("size").toULongLong();
+        } else {
+            sizeB = itemB.size();
+        }
+        if (sizeA < sizeB) {
+            return -1;
+        } else if (sizeA > sizeB) {
+            return +1;
         }
         break;
     }
@@ -1814,9 +2237,20 @@ int KFileItemModel::sortRoleCompare(const ItemData* a, const ItemData* b, const
         const long long dateTimeA = itemA.entry().numberValue(KIO::UDSEntry::UDS_MODIFICATION_TIME, -1);
         const long long dateTimeB = itemB.entry().numberValue(KIO::UDSEntry::UDS_MODIFICATION_TIME, -1);
         if (dateTimeA < dateTimeB) {
-            result = -1;
+            return -1;
+        } else if (dateTimeA > dateTimeB) {
+            return +1;
+        }
+        break;
+    }
+
+    case AccessTimeRole: {
+        const long long dateTimeA = itemA.entry().numberValue(KIO::UDSEntry::UDS_ACCESS_TIME, -1);
+        const long long dateTimeB = itemB.entry().numberValue(KIO::UDSEntry::UDS_ACCESS_TIME, -1);
+        if (dateTimeA < dateTimeB) {
+            return -1;
         } else if (dateTimeA > dateTimeB) {
-            result = +1;
+            return +1;
         }
         break;
     }
@@ -1825,9 +2259,9 @@ int KFileItemModel::sortRoleCompare(const ItemData* a, const ItemData* b, const
         const long long dateTimeA = itemA.entry().numberValue(KIO::UDSEntry::UDS_CREATION_TIME, -1);
         const long long dateTimeB = itemB.entry().numberValue(KIO::UDSEntry::UDS_CREATION_TIME, -1);
         if (dateTimeA < dateTimeB) {
-            result = -1;
+            return -1;
         } else if (dateTimeA > dateTimeB) {
-            result = +1;
+            return +1;
         }
         break;
     }
@@ -1836,9 +2270,9 @@ int KFileItemModel::sortRoleCompare(const ItemData* a, const ItemData* b, const
         const QDateTime dateTimeA = a->values.value("deletiontime").toDateTime();
         const QDateTime dateTimeB = b->values.value("deletiontime").toDateTime();
         if (dateTimeA < dateTimeB) {
-            result = -1;
+            return -1;
         } else if (dateTimeA > dateTimeB) {
-            result = +1;
+            return +1;
         }
         break;
     }
@@ -1846,6 +2280,8 @@ int KFileItemModel::sortRoleCompare(const ItemData* a, const ItemData* b, const
     case RatingRole:
     case WidthRole:
     case HeightRole:
+    case PublisherRole:
+    case PageCountRole:
     case WordCountRole:
     case LineCountRole:
     case TrackRole:
@@ -1854,14 +2290,27 @@ int KFileItemModel::sortRoleCompare(const ItemData* a, const ItemData* b, const
         break;
     }
 
+    case DimensionsRole: {
+        const QByteArray role = roleForType(m_sortRole);
+        const QSize dimensionsA = a->values.value(role).toSize();
+        const QSize dimensionsB = b->values.value(role).toSize();
+
+        if (dimensionsA.width() == dimensionsB.width()) {
+            result = dimensionsA.height() - dimensionsB.height();
+        } else {
+            result = dimensionsA.width() - dimensionsB.width();
+        }
+        break;
+    }
+
     default: {
         const QByteArray role = roleForType(m_sortRole);
         const QString roleValueA = a->values.value(role).toString();
         const QString roleValueB = b->values.value(role).toString();
         if (!roleValueA.isEmpty() && roleValueB.isEmpty()) {
-            result = -1;
+            return -1;
         } else if (roleValueA.isEmpty() && !roleValueB.isEmpty()) {
-            result = +1;
+            return +1;
         } else if (isRoleValueNatural(m_sortRole)) {
             result = stringCompare(roleValueA, roleValueB, collator);
         } else {
@@ -1869,7 +2318,6 @@ int KFileItemModel::sortRoleCompare(const ItemData* a, const ItemData* b, const
         }
         break;
     }
-
     }
 
     if (result != 0) {
@@ -1895,12 +2343,131 @@ int KFileItemModel::sortRoleCompare(const ItemData* a, const ItemData* b, const
     return QString::compare(itemA.url().url(), itemB.url().url(), Qt::CaseSensitive);
 }
 
-int KFileItemModel::stringCompare(const QString& a, const QString& b, const QCollator& collator) const
+int KFileItemModel::groupRoleCompare(const ItemData *a, const ItemData *b, const QCollator &collator) const
+{
+    // Unlike sortRoleCompare, this function can and often will return 0.
+    int result = 0;
+
+    ItemGroupInfo groupA, groupB;
+    switch (m_groupRole) {
+    case NoRole:
+        // Non-trivial grouping behavior might be handled there in the future.
+        return 0;
+    case NameRole:
+        groupA = nameRoleGroup(a, false);
+        groupB = nameRoleGroup(b, false);
+        break;
+    case SizeRole:
+        groupA = sizeRoleGroup(a, false);
+        groupB = sizeRoleGroup(b, false);
+        break;
+    case ModificationTimeRole:
+        groupA = timeRoleGroup(
+            [](const ItemData *item) {
+                return item->item.time(KFileItem::ModificationTime);
+            },
+            a,
+            false);
+        groupB = timeRoleGroup(
+            [](const ItemData *item) {
+                return item->item.time(KFileItem::ModificationTime);
+            },
+            b,
+            false);
+        break;
+    case CreationTimeRole:
+        groupA = timeRoleGroup(
+            [](const ItemData *item) {
+                return item->item.time(KFileItem::CreationTime);
+            },
+            a,
+            false);
+        groupB = timeRoleGroup(
+            [](const ItemData *item) {
+                return item->item.time(KFileItem::CreationTime);
+            },
+            b,
+            false);
+        break;
+    case AccessTimeRole:
+        groupA = timeRoleGroup(
+            [](const ItemData *item) {
+                return item->item.time(KFileItem::AccessTime);
+            },
+            a,
+            false);
+        groupB = timeRoleGroup(
+            [](const ItemData *item) {
+                return item->item.time(KFileItem::AccessTime);
+            },
+            b,
+            false);
+        break;
+    case DeletionTimeRole:
+        groupA = timeRoleGroup(
+            [](const ItemData *item) {
+                return item->values.value("deletiontime").toDateTime();
+            },
+            a,
+            false);
+        groupB = timeRoleGroup(
+            [](const ItemData *item) {
+                return item->values.value("deletiontime").toDateTime();
+            },
+            b,
+            false);
+        break;
+    case PermissionsRole:
+        groupA = permissionRoleGroup(a, false);
+        groupB = permissionRoleGroup(b, false);
+        break;
+    case RatingRole:
+        groupA = ratingRoleGroup(a, false);
+        groupB = ratingRoleGroup(b, false);
+        break;
+    case TypeRole:
+        groupA = typeRoleGroup(a);
+        groupB = typeRoleGroup(b);
+        break;
+    default: {
+        groupA = genericStringRoleGroup(groupRole(), a);
+        groupB = genericStringRoleGroup(groupRole(), b);
+        break;
+    }
+    }
+    if (groupA.comparable < groupB.comparable) {
+        result = -1;
+    } else if (groupA.comparable > groupB.comparable) {
+        result = 1;
+    } else {
+        result = stringCompare(groupA.text, groupB.text, collator);
+    }
+    return result;
+}
+
+int KFileItemModel::stringCompare(const QString &a, const QString &b, const QCollator &collator) const
 {
     QMutexLocker collatorLock(s_collatorMutex());
 
     if (m_naturalSorting) {
-        return collator.compare(a, b);
+        // Split extension, taking into account it can be empty
+        constexpr QString::SectionFlags flags = QString::SectionSkipEmpty | QString::SectionIncludeLeadingSep;
+
+        // Sort by baseName first
+        const QString aBaseName = a.section('.', 0, 0, flags);
+        const QString bBaseName = b.section('.', 0, 0, flags);
+
+        const int res = collator.compare(aBaseName, bBaseName);
+        if (res != 0 || (aBaseName.length() == a.length() && bBaseName.length() == b.length())) {
+            return res;
+        }
+
+        // sliced() has undefined behavior when pos < 0 or pos > size().
+        Q_ASSERT(aBaseName.length() <= a.length() && aBaseName.length() >= 0);
+        Q_ASSERT(bBaseName.length() <= b.length() && bBaseName.length() >= 0);
+
+        // baseNames were equal, sort by extension
+        return collator.compare(a.sliced(aBaseName.length()), b.sliced(bBaseName.length()));
     }
 
     const int result = QString::compare(a, b, collator.caseSensitivity());
@@ -1914,121 +2481,122 @@ int KFileItemModel::stringCompare(const QString& a, const QString& b, const QCol
     return QString::compare(a, b, Qt::CaseSensitive);
 }
 
-QList<QPair<int, QVariant> > KFileItemModel::nameRoleGroups() const
+KFileItemModel::ItemGroupInfo KFileItemModel::nameRoleGroup(const ItemData *itemData, bool withString) const
 {
-    Q_ASSERT(!m_itemData.isEmpty());
-
-    const int maxIndex = count() - 1;
-    QList<QPair<int, QVariant> > groups;
-
-    QString groupValue;
+    static bool oldWithString;
+    static ItemGroupInfo oldGroupInfo;
+    static QChar oldFirstChar;
+    ItemGroupInfo groupInfo;
     QChar firstChar;
-    for (int i = 0; i <= maxIndex; ++i) {
-        if (isChildItem(i)) {
-            continue;
-        }
-
-        const QString name = m_itemData.at(i)->item.text();
 
-        // Use the first character of the name as group indication
-        QChar newFirstChar = name.at(0).toUpper();
-        if (newFirstChar == QLatin1Char('~') && name.length() > 1) {
-            newFirstChar = name.at(1).toUpper();
-        }
+    const QString name = itemData->item.text();
 
-        if (firstChar != newFirstChar) {
-            QString newGroupValue;
-            if (newFirstChar.isLetter()) {
-
-                if (m_collator.compare(newFirstChar, QChar(QLatin1Char('A'))) >= 0 && m_collator.compare(newFirstChar, QChar(QLatin1Char('Z'))) <= 0) {
-                    // WARNING! Symbols based on latin 'Z' like 'Z' with acute are treated wrong as non Latin and put in a new group.
-
-                    // Try to find a matching group in the range 'A' to 'Z'.
-                    static std::vector<QChar> lettersAtoZ;
-                    lettersAtoZ.reserve('Z' - 'A' + 1);
-                    if (lettersAtoZ.empty()) {
-                        for (char c = 'A'; c <= 'Z'; ++c) {
-                            lettersAtoZ.push_back(QLatin1Char(c));
-                        }
-                    }
+    QMutexLocker collatorLock(s_collatorMutex());
 
-                    auto localeAwareLessThan = [this](QChar c1, QChar c2) -> bool {
-                        return m_collator.compare(c1, c2) < 0;
-                    };
+    // Use the first character of the name as group indication
+    firstChar = name.at(0).toUpper();
+    
+    if (firstChar == oldFirstChar && withString == oldWithString) {
+        return oldGroupInfo;
+    }
+    if (firstChar == QLatin1Char('~') && name.length() > 1) {
+        firstChar = name.at(1).toUpper();
+    }
+    if (firstChar.isLetter()) {
+        if (m_collator.compare(firstChar, QChar(QLatin1Char('A'))) >= 0 && m_collator.compare(firstChar, QChar(QLatin1Char('Z'))) <= 0) {
+            // WARNING! Symbols based on latin 'Z' like 'Z' with acute are treated wrong as non Latin and put in a new group.
+
+            // Try to find a matching group in the range 'A' to 'Z'.
+            static std::vector<QChar> lettersAtoZ;
+            lettersAtoZ.reserve('Z' - 'A' + 1);
+            if (lettersAtoZ.empty()) {
+                for (char c = 'A'; c <= 'Z'; ++c) {
+                    lettersAtoZ.push_back(QLatin1Char(c));
+                }
+            }
 
-                    std::vector<QChar>::iterator it = std::lower_bound(lettersAtoZ.begin(), lettersAtoZ.end(), newFirstChar, localeAwareLessThan);
-                    if (it != lettersAtoZ.end()) {
-                        if (localeAwareLessThan(newFirstChar, *it)) {
-                            // newFirstChar belongs to the group preceding *it.
-                            // Example: for an umlaut 'A' in the German locale, *it would be 'B' now.
-                            --it;
-                        }
-                        newGroupValue = *it;
-                    }
+            auto localeAwareLessThan = [this](QChar c1, QChar c2) -> bool {
+                return m_collator.compare(c1, c2) < 0;
+            };
 
-                } else {
-                    // Symbols from non Latin-based scripts
-                    newGroupValue = newFirstChar;
+            std::vector<QChar>::iterator it = std::lower_bound(lettersAtoZ.begin(), lettersAtoZ.end(), firstChar, localeAwareLessThan);
+            if (it != lettersAtoZ.end()) {
+                if (localeAwareLessThan(firstChar, *it)) {
+                    // newFirstChar belongs to the group preceding *it.
+                    // Example: for an umlaut 'A' in the German locale, *it would be 'B' now.
+                    --it;
                 }
-            } else if (newFirstChar >= QLatin1Char('0') && newFirstChar <= QLatin1Char('9')) {
-                // Apply group '0 - 9' for any name that starts with a digit
-                newGroupValue = i18nc("@title:group Groups that start with a digit", "0 - 9");
-            } else {
-                newGroupValue = i18nc("@title:group", "Others");
+                if (withString) {
+                    groupInfo.text = *it;
+                }
+                groupInfo.comparable = (*it).unicode();
             }
 
-            if (newGroupValue != groupValue) {
-                groupValue = newGroupValue;
-                groups.append(QPair<int, QVariant>(i, newGroupValue));
+        } else {
+            // Symbols from non Latin-based scripts
+            if (withString) {
+                groupInfo.text = firstChar;
             }
-
-            firstChar = newFirstChar;
+            groupInfo.comparable = firstChar.unicode();
         }
+    } else if (firstChar >= QLatin1Char('0') && firstChar <= QLatin1Char('9')) {
+        // Apply group '0 - 9' for any name that starts with a digit
+        if (withString) {
+            groupInfo.text = i18nc("@title:group Groups that start with a digit", "0 - 9");
+        }
+        groupInfo.comparable = (int)'0';
+    } else {
+        if (withString) {
+            groupInfo.text = i18nc("@title:group", "Others");
+        }
+        groupInfo.comparable = (int)'.';
     }
-    return groups;
+    oldWithString = withString;
+    oldFirstChar = firstChar;
+    oldGroupInfo = groupInfo;
+    return groupInfo;
 }
 
-QList<QPair<int, QVariant> > KFileItemModel::sizeRoleGroups() const
+KFileItemModel::ItemGroupInfo KFileItemModel::sizeRoleGroup(const ItemData *itemData, bool withString) const
 {
-    Q_ASSERT(!m_itemData.isEmpty());
+    ItemGroupInfo groupInfo;
+    KIO::filesize_t fileSize;
 
-    const int maxIndex = count() - 1;
-    QList<QPair<int, QVariant> > groups;
-
-    QString groupValue;
-    for (int i = 0; i <= maxIndex; ++i) {
-        if (isChildItem(i)) {
-            continue;
-        }
+    const KFileItem item = itemData->item;
+    fileSize = !item.isNull() ? item.size() : ~0U;
 
-        const KFileItem& item = m_itemData.at(i)->item;
-        const KIO::filesize_t fileSize = !item.isNull() ? item.size() : ~0U;
-        QString newGroupValue;
-        if (!item.isNull() && item.isDir()) {
-            newGroupValue = i18nc("@title:group Size", "Folders");
-        } else if (fileSize < 5 * 1024 * 1024) {
-            newGroupValue = i18nc("@title:group Size", "Small");
-        } else if (fileSize < 10 * 1024 * 1024) {
-            newGroupValue = i18nc("@title:group Size", "Medium");
+    groupInfo.comparable = -1; // None
+    if (!item.isNull() && item.isDir()) {
+        if (ContentDisplaySettings::directorySizeMode() != ContentDisplaySettings::EnumDirectorySizeMode::ContentSize) {
+            groupInfo.comparable = 0; // Folders
         } else {
-            newGroupValue = i18nc("@title:group Size", "Big");
+            fileSize = itemData->values.value("size").toULongLong();
         }
-
-        if (newGroupValue != groupValue) {
-            groupValue = newGroupValue;
-            groups.append(QPair<int, QVariant>(i, newGroupValue));
+    }
+    if (groupInfo.comparable < 0) {
+        if (fileSize < 5 * 1024 * 1024) { // < 5 MB
+            groupInfo.comparable = 1; // Small
+        } else if (fileSize < 10 * 1024 * 1024) { // < 10 MB
+            groupInfo.comparable = 2; // Medium
+        } else {
+            groupInfo.comparable = 3; // Big
         }
     }
 
-    return groups;
+    if (withString) {
+        char const *groupNames[] = {"Folders", "Small", "Medium", "Big"};
+        groupInfo.text = i18nc("@title:group Size", groupNames[groupInfo.comparable]);
+    }
+    return groupInfo;
 }
 
-QList<QPair<int, QVariant> > KFileItemModel::timeRoleGroups(const std::function<QDateTime(const ItemData *)> &fileTimeCb) const
+KFileItemModel::ItemGroupInfo
+KFileItemModel::timeRoleGroup(const std::function<QDateTime(const ItemData *)> &fileTimeCb, const ItemData *itemData, bool withString) const
 {
-    Q_ASSERT(!m_itemData.isEmpty());
-
-    const int maxIndex = count() - 1;
-    QList<QPair<int, QVariant> > groups;
+    static bool oldWithString;
+    static ItemGroupInfo oldGroupInfo;
+    static QDate oldFileDate;
+    ItemGroupInfo groupInfo;
 
     const QDate currentDate = QDate::currentDate();
 
@@ -2039,6 +2607,7 @@ QList<QPair<int, QVariant> > KFileItemModel::timeRoleGroups(const std::function<
             continue;
         }
 
+        const QLocale locale;
         const QDateTime fileTime = fileTimeCb(m_itemData.at(i));
         const QDate fileDate = fileTime.date();
         if (fileDate == previousFileDate) {
@@ -2049,261 +2618,447 @@ QList<QPair<int, QVariant> > KFileItemModel::timeRoleGroups(const std::function<
 
         const int daysDistance = fileDate.daysTo(currentDate);
 
-        QString newGroupValue;
-        if (currentDate.year() == fileDate.year() &&
-            currentDate.month() == fileDate.month()) {
-
+    if (fileDate == oldFileDate && withString == oldWithString) {
+        return oldGroupInfo;
+    }
+    // Simplified grouping algorithm, preserving dates
+    // but not taking "pretty printing" into account
+    if (currentDate.year() == fileDate.year() && currentDate.month() == fileDate.month()) {
+        if (daysDistance < 7) {
+            groupInfo.comparable = daysDistance; // Today, Yesterday and week days
+        } else if (daysDistance < 14) {
+            groupInfo.comparable = 10; // One Week Ago
+        } else if (daysDistance < 21) {
+            groupInfo.comparable = 20; // Two Weeks Ago
+        } else if (daysDistance < 28) {
+            groupInfo.comparable = 30; // Three Weeks Ago
+        } else {
+            groupInfo.comparable = 40; // Earlier This Month
+        }
+    } else {
+        const QDate lastMonthDate = currentDate.addMonths(-1);
+        if (lastMonthDate.year() == fileDate.year() && lastMonthDate.month() == fileDate.month()) {
+            if (daysDistance < 7) {
+                groupInfo.comparable = daysDistance; // Today, Yesterday and week days (Month, Year)
+            } else if (daysDistance < 14) {
+                groupInfo.comparable = 11; // One Week Ago (Month, Year)
+            } else if (daysDistance < 21) {
+                groupInfo.comparable = 21; // Two Weeks Ago (Month, Year)
+            } else if (daysDistance < 28) {
+                groupInfo.comparable = 31; // Three Weeks Ago (Month, Year)
+            } else {
+                groupInfo.comparable = 41; // Earlier on Month, Year
+            }
+        } else {
+            // The trick will fail for dates past April, 178956967 or before 1 AD.
+            groupInfo.comparable = 2147483647 - (fileDate.year() * 12 + fileDate.month() - 1); // Month, Year; newer < older
+        }
+    }
+    if (withString) {
+        if (currentDate.year() == fileDate.year() && currentDate.month() == fileDate.month()) {
             switch (daysDistance / 7) {
             case 0:
                 switch (daysDistance) {
-                case 0:  newGroupValue = i18nc("@title:group Date", "Today"); break;
-                case 1:  newGroupValue = i18nc("@title:group Date", "Yesterday"); break;
+                case 0:
+                    groupInfo.text = i18nc("@title:group Date", "Today");
+                    break;
+                case 1:
+                    groupInfo.text = i18nc("@title:group Date", "Yesterday");
+                    break;
                 default:
-                    newGroupValue = fileTime.toString(
-                        i18nc("@title:group Date: The week day name: dddd", "dddd"));
-                    newGroupValue = i18nc("Can be used to script translation of \"dddd\""
-                        "with context @title:group Date", "%1", newGroupValue);
+                    newGroupValue = locale.toString(fileTime, i18nc("@title:group Date: The week day name: dddd", "dddd"));
+                    newGroupValue = i18nc(
+                        "Can be used to script translation of \"dddd\""
+                        "with context @title:group Date",
+                        "%1",
+                        groupInfo.text);
                 }
                 break;
             case 1:
-                newGroupValue = i18nc("@title:group Date", "One Week Ago");
+                groupInfo.text = i18nc("@title:group Date", "One Week Ago");
                 break;
             case 2:
-                newGroupValue = i18nc("@title:group Date", "Two Weeks Ago");
+                groupInfo.text = i18nc("@title:group Date", "Two Weeks Ago");
                 break;
             case 3:
-                newGroupValue = i18nc("@title:group Date", "Three Weeks Ago");
+                groupInfo.text = i18nc("@title:group Date", "Three Weeks Ago");
                 break;
             case 4:
             case 5:
-                newGroupValue = i18nc("@title:group Date", "Earlier this Month");
+                groupInfo.text = i18nc("@title:group Date", "Earlier this Month");
                 break;
             default:
                 Q_ASSERT(false);
             }
         } else {
             const QDate lastMonthDate = currentDate.addMonths(-1);
-            if  (lastMonthDate.year() == fileDate.year() &&
-                 lastMonthDate.month() == fileDate.month()) {
-
+            if (lastMonthDate.year() == fileDate.year() && lastMonthDate.month() == fileDate.month()) {
                 if (daysDistance == 1) {
-                    const KLocalizedString format = ki18nc("@title:group Date: "
-                                                    "MMMM is full month name in current locale, and yyyy is "
-                                                    "full year number", "'Yesterday' (MMMM, yyyy)");
+                    const KLocalizedString format = ki18nc(
+                        "@title:group Date: "
+                        "MMMM is full month name in current locale, and yyyy is "
+                        "full year number. You must keep the ' don't use any fancy \" or « or similar. The ' is not shown to the user, it's there to mark a "
+                        "part of the text that should not be formatted as a date",
+                        "'Yesterday' (MMMM, yyyy)");
                     const QString translatedFormat = format.toString();
-                    if (translatedFormat.count(QLatin1Char('\'')) == 2) {
-                        newGroupValue = fileTime.toString(translatedFormat);
-                        newGroupValue = i18nc("Can be used to script translation of "
+                    if (const int count = translatedFormat.count(QLatin1Char('\'')); count >= 2 && count % 2 == 0) {
+                        newGroupValue = locale.toString(fileTime, translatedFormat);
+                        newGroupValue = i18nc(
+                            "Can be used to script translation of "
                             "\"'Yesterday' (MMMM, yyyy)\" with context @title:group Date",
-                            "%1", newGroupValue);
+                            "%1",
+                            groupInfo.text);
                     } else {
-                        qCWarning(DolphinDebug).nospace() << "A wrong translation was found: " << translatedFormat << ". Please file a bug report at bugs.kde.org";
-                        const QString untranslatedFormat = format.toString({ QLatin1String("en_US") });
-                        newGroupValue = fileTime.toString(untranslatedFormat);
+                        qCWarning(DolphinDebug).nospace()
+                            << "A wrong translation was found: " << translatedFormat << ". Please file a bug report at bugs.kde.org";
+                        const QString untranslatedFormat = format.toString({QLatin1String("en_US")});
+                        newGroupValue = locale.toString(fileTime, untranslatedFormat);
                     }
                 } else if (daysDistance <= 7) {
-                    newGroupValue = fileTime.toString(i18nc("@title:group Date: "
-                        "The week day name: dddd, MMMM is full month name "
-                        "in current locale, and yyyy is full year number",
-                        "dddd (MMMM, yyyy)"));
-                    newGroupValue = i18nc("Can be used to script translation of "
+                    newGroupValue = locale.toString(fileTime,
+                                                    i18nc("@title:group Date: "
+                                                          "The week day name: dddd, MMMM is full month name "
+                                                          "in current locale, and yyyy is full year number.",
+                                                          "dddd (MMMM, yyyy)"));
+                    newGroupValue = i18nc(
+                        "Can be used to script translation of "
                         "\"dddd (MMMM, yyyy)\" with context @title:group Date",
-                        "%1", newGroupValue);
-                } else if (daysDistance <= 7 * 2) {
-                    const KLocalizedString format = ki18nc("@title:group Date: "
-                                                           "MMMM is full month name in current locale, and yyyy is "
-                                                           "full year number", "'One Week Ago' (MMMM, yyyy)");
+                        "%1",
+                        groupInfo.text);
+                } else if (daysDistance < 7 * 2) {
+                    const KLocalizedString format = ki18nc(
+                        "@title:group Date: "
+                        "MMMM is full month name in current locale, and yyyy is "
+                        "full year number. You must keep the ' don't use any fancy \" or « or similar. The ' is not shown to the user, it's there to mark a "
+                        "part of the text that should not be formatted as a date",
+                        "'One Week Ago' (MMMM, yyyy)");
                     const QString translatedFormat = format.toString();
-                    if (translatedFormat.count(QLatin1Char('\'')) == 2) {
-                        newGroupValue = fileTime.toString(translatedFormat);
-                        newGroupValue = i18nc("Can be used to script translation of "
+                    if (const int count = translatedFormat.count(QLatin1Char('\'')); count >= 2 && count % 2 == 0) {
+                        newGroupValue = locale.toString(fileTime, translatedFormat);
+                        newGroupValue = i18nc(
+                            "Can be used to script translation of "
                             "\"'One Week Ago' (MMMM, yyyy)\" with context @title:group Date",
-                            "%1", newGroupValue);
+                            "%1",
+                            groupInfo.text);
                     } else {
-                        qCWarning(DolphinDebug).nospace() << "A wrong translation was found: " << translatedFormat << ". Please file a bug report at bugs.kde.org";
-                        const QString untranslatedFormat = format.toString({ QLatin1String("en_US") });
-                        newGroupValue = fileTime.toString(untranslatedFormat);
+                        qCWarning(DolphinDebug).nospace()
+                            << "A wrong translation was found: " << translatedFormat << ". Please file a bug report at bugs.kde.org";
+                        const QString untranslatedFormat = format.toString({QLatin1String("en_US")});
+                        newGroupValue = locale.toString(fileTime, untranslatedFormat);
                     }
-                } else if (daysDistance <= 7 * 3) {
-                    const KLocalizedString format = ki18nc("@title:group Date: "
-                                                           "MMMM is full month name in current locale, and yyyy is "
-                                                           "full year number", "'Two Weeks Ago' (MMMM, yyyy)");
+                } else if (daysDistance < 7 * 3) {
+                    const KLocalizedString format = ki18nc(
+                        "@title:group Date: "
+                        "MMMM is full month name in current locale, and yyyy is "
+                        "full year number. You must keep the ' don't use any fancy \" or « or similar. The ' is not shown to the user, it's there to mark a "
+                        "part of the text that should not be formatted as a date",
+                        "'Two Weeks Ago' (MMMM, yyyy)");
                     const QString translatedFormat = format.toString();
-                    if (translatedFormat.count(QLatin1Char('\'')) == 2) {
-                        newGroupValue = fileTime.toString(translatedFormat);
-                        newGroupValue = i18nc("Can be used to script translation of "
+                    if (const int count = translatedFormat.count(QLatin1Char('\'')); count >= 2 && count % 2 == 0) {
+                        newGroupValue = locale.toString(fileTime, translatedFormat);
+                        newGroupValue = i18nc(
+                            "Can be used to script translation of "
                             "\"'Two Weeks Ago' (MMMM, yyyy)\" with context @title:group Date",
-                            "%1", newGroupValue);
+                            "%1",
+                            groupInfo.text);
                     } else {
-                        qCWarning(DolphinDebug).nospace() << "A wrong translation was found: " << translatedFormat << ". Please file a bug report at bugs.kde.org";
-                        const QString untranslatedFormat = format.toString({ QLatin1String("en_US") });
-                        newGroupValue = fileTime.toString(untranslatedFormat);
+                        qCWarning(DolphinDebug).nospace()
+                            << "A wrong translation was found: " << translatedFormat << ". Please file a bug report at bugs.kde.org";
+                        const QString untranslatedFormat = format.toString({QLatin1String("en_US")});
+                        newGroupValue = locale.toString(fileTime, untranslatedFormat);
                     }
-                } else if (daysDistance <= 7 * 4) {
-                    const KLocalizedString format = ki18nc("@title:group Date: "
-                                                           "MMMM is full month name in current locale, and yyyy is "
-                                                           "full year number", "'Three Weeks Ago' (MMMM, yyyy)");
+                } else if (daysDistance < 7 * 4) {
+                    const KLocalizedString format = ki18nc(
+                        "@title:group Date: "
+                        "MMMM is full month name in current locale, and yyyy is "
+                        "full year number. You must keep the ' don't use any fancy \" or « or similar. The ' is not shown to the user, it's there to mark a "
+                        "part of the text that should not be formatted as a date",
+                        "'Three Weeks Ago' (MMMM, yyyy)");
                     const QString translatedFormat = format.toString();
-                    if (translatedFormat.count(QLatin1Char('\'')) == 2) {
-                        newGroupValue = fileTime.toString(translatedFormat);
-                        newGroupValue = i18nc("Can be used to script translation of "
+                    if (const int count = translatedFormat.count(QLatin1Char('\'')); count >= 2 && count % 2 == 0) {
+                        newGroupValue = locale.toString(fileTime, translatedFormat);
+                        newGroupValue = i18nc(
+                            "Can be used to script translation of "
                             "\"'Three Weeks Ago' (MMMM, yyyy)\" with context @title:group Date",
-                            "%1", newGroupValue);
+                            "%1",
+                            groupInfo.text);
                     } else {
-                        qCWarning(DolphinDebug).nospace() << "A wrong translation was found: " << translatedFormat << ". Please file a bug report at bugs.kde.org";
-                        const QString untranslatedFormat = format.toString({ QLatin1String("en_US") });
-                        newGroupValue = fileTime.toString(untranslatedFormat);
+                        qCWarning(DolphinDebug).nospace()
+                            << "A wrong translation was found: " << translatedFormat << ". Please file a bug report at bugs.kde.org";
+                        const QString untranslatedFormat = format.toString({QLatin1String("en_US")});
+                        newGroupValue = locale.toString(fileTime, untranslatedFormat);
                     }
                 } else {
-                    const KLocalizedString format = ki18nc("@title:group Date: "
-                                                           "MMMM is full month name in current locale, and yyyy is "
-                                                           "full year number", "'Earlier on' MMMM, yyyy");
+                    const KLocalizedString format = ki18nc(
+                        "@title:group Date: "
+                        "MMMM is full month name in current locale, and yyyy is "
+                        "full year number. You must keep the ' don't use any fancy \" or « or similar. The ' is not shown to the user, it's there to mark a "
+                        "part of the text that should not be formatted as a date",
+                        "'Earlier on' MMMM, yyyy");
                     const QString translatedFormat = format.toString();
-                    if (translatedFormat.count(QLatin1Char('\'')) == 2) {
-                        newGroupValue = fileTime.toString(translatedFormat);
-                        newGroupValue = i18nc("Can be used to script translation of "
+                    if (const int count = translatedFormat.count(QLatin1Char('\'')); count >= 2 && count % 2 == 0) {
+                        newGroupValue = locale.toString(fileTime, translatedFormat);
+                        newGroupValue = i18nc(
+                            "Can be used to script translation of "
                             "\"'Earlier on' MMMM, yyyy\" with context @title:group Date",
-                            "%1", newGroupValue);
+                            "%1",
+                            groupInfo.text);
                     } else {
-                        qCWarning(DolphinDebug).nospace() << "A wrong translation was found: " << translatedFormat << ". Please file a bug report at bugs.kde.org";
-                        const QString untranslatedFormat = format.toString({ QLatin1String("en_US") });
-                        newGroupValue = fileTime.toString(untranslatedFormat);
+                        qCWarning(DolphinDebug).nospace()
+                            << "A wrong translation was found: " << translatedFormat << ". Please file a bug report at bugs.kde.org";
+                        const QString untranslatedFormat = format.toString({QLatin1String("en_US")});
+                        newGroupValue = locale.toString(fileTime, untranslatedFormat);
                     }
                 }
             } else {
-                newGroupValue = fileTime.toString(i18nc("@title:group "
-                    "The month and year: MMMM is full month name in current locale, "
-                    "and yyyy is full year number", "MMMM, yyyy"));
-                newGroupValue = i18nc("Can be used to script translation of "
+                newGroupValue = locale.toString(fileTime,
+                                                i18nc("@title:group "
+                                                      "The month and year: MMMM is full month name in current locale, "
+                                                      "and yyyy is full year number",
+                                                      "MMMM, yyyy"));
+                newGroupValue = i18nc(
+                    "Can be used to script translation of "
                     "\"MMMM, yyyy\" with context @title:group Date",
-                    "%1", newGroupValue);
+                    "%1",
+                    groupInfo.text);
             }
         }
-
-        if (newGroupValue != groupValue) {
-            groupValue = newGroupValue;
-            groups.append(QPair<int, QVariant>(i, newGroupValue));
-        }
     }
-
-    return groups;
+    oldWithString = withString;
+    oldFileDate = fileDate;
+    oldGroupInfo = groupInfo;
+    return groupInfo;
 }
 
-QList<QPair<int, QVariant> > KFileItemModel::permissionRoleGroups() const
+KFileItemModel::ItemGroupInfo KFileItemModel::permissionRoleGroup(const ItemData *itemData, bool withString) const
 {
-    Q_ASSERT(!m_itemData.isEmpty());
+    static bool oldWithString;
+    static ItemGroupInfo oldGroupInfo;
+    static QFileDevice::Permissions oldPermissions;
+    ItemGroupInfo groupInfo;
 
-    const int maxIndex = count() - 1;
-    QList<QPair<int, QVariant> > groups;
-
-    QString permissionsString;
-    QString groupValue;
-    for (int i = 0; i <= maxIndex; ++i) {
-        if (isChildItem(i)) {
-            continue;
-        }
-
-        const ItemData* itemData = m_itemData.at(i);
-        const QString newPermissionsString = itemData->values.value("permissions").toString();
-        if (newPermissionsString == permissionsString) {
-            continue;
-        }
-        permissionsString = newPermissionsString;
-
-        const QFileInfo info(itemData->item.url().toLocalFile());
+    const QFileInfo info(itemData->item.url().toLocalFile());
+    const QFileDevice::Permissions permissions = info.permissions();
+    if (permissions == oldPermissions && withString == oldWithString) {
+        return oldGroupInfo;
+    }
+    groupInfo.comparable = (int)permissions;
 
+    if (withString) {
         // Set user string
         QString user;
-        if (info.permission(QFile::ReadUser)) {
+        if (permissions & QFile::ReadUser) {
             user = i18nc("@item:intext Access permission, concatenated", "Read, ");
         }
-        if (info.permission(QFile::WriteUser)) {
+        if (permissions & QFile::WriteUser) {
             user += i18nc("@item:intext Access permission, concatenated", "Write, ");
         }
-        if (info.permission(QFile::ExeUser)) {
+        if (permissions & QFile::ExeUser) {
             user += i18nc("@item:intext Access permission, concatenated", "Execute, ");
         }
-        user = user.isEmpty() ? i18nc("@item:intext Access permission, concatenated", "Forbidden") : user.mid(0, user.count() - 2);
+        user = user.isEmpty() ? i18nc("@item:intext Access permission, concatenated", "Forbidden") : user.mid(0, user.length() - 2);
 
         // Set group string
         QString group;
-        if (info.permission(QFile::ReadGroup)) {
+        if (permissions & QFile::ReadGroup) {
             group = i18nc("@item:intext Access permission, concatenated", "Read, ");
         }
-        if (info.permission(QFile::WriteGroup)) {
+        if (permissions & QFile::WriteGroup) {
             group += i18nc("@item:intext Access permission, concatenated", "Write, ");
         }
-        if (info.permission(QFile::ExeGroup)) {
+        if (permissions & QFile::ExeGroup) {
             group += i18nc("@item:intext Access permission, concatenated", "Execute, ");
         }
-        group = group.isEmpty() ? i18nc("@item:intext Access permission, concatenated", "Forbidden") : group.mid(0, group.count() - 2);
+        group = group.isEmpty() ? i18nc("@item:intext Access permission, concatenated", "Forbidden") : group.mid(0, group.length() - 2);
 
         // Set others string
         QString others;
-        if (info.permission(QFile::ReadOther)) {
+        if (permissions & QFile::ReadOther) {
             others = i18nc("@item:intext Access permission, concatenated", "Read, ");
         }
-        if (info.permission(QFile::WriteOther)) {
+        if (permissions & QFile::WriteOther) {
             others += i18nc("@item:intext Access permission, concatenated", "Write, ");
         }
-        if (info.permission(QFile::ExeOther)) {
+        if (permissions & QFile::ExeOther) {
             others += i18nc("@item:intext Access permission, concatenated", "Execute, ");
         }
-        others = others.isEmpty() ? i18nc("@item:intext Access permission, concatenated", "Forbidden") : others.mid(0, others.count() - 2);
+        others = others.isEmpty() ? i18nc("@item:intext Access permission, concatenated", "Forbidden") : others.mid(0, others.length() - 2);
+        groupInfo.text = i18nc("@title:group Files and folders by permissions", "User: %1 | Group: %2 | Others: %3", user, group, others);
+    }
+    oldWithString = withString;
+    oldPermissions = permissions;
+    oldGroupInfo = groupInfo;
+    return groupInfo;
+}
 
-        const QString newGroupValue = i18nc("@title:group Files and folders by permissions", "User: %1 | Group: %2 | Others: %3", user, group, others);
-        if (newGroupValue != groupValue) {
-            groupValue = newGroupValue;
-            groups.append(QPair<int, QVariant>(i, newGroupValue));
+KFileItemModel::ItemGroupInfo KFileItemModel::ratingRoleGroup(const ItemData *itemData, bool withString) const
+{
+    ItemGroupInfo groupInfo;
+    groupInfo.comparable = itemData->values.value("rating", 0).toInt();
+    if (withString) {
+        // Dolphin does not currently use string representation of star rating
+        // as stars are rendered as graphics in group headers.
+        groupInfo.text = i18nc("@item:intext Rated N (stars)", "Rated %i", QString::number(groupInfo.comparable));
+    }
+    return groupInfo;
+}
+
+KFileItemModel::ItemGroupInfo KFileItemModel::genericStringRoleGroup(const QByteArray &role, const ItemData *itemData) const
+{
+    return {0, itemData->values.value(role).toString()};
+}
+
+QList<QPair<int, QVariant>> KFileItemModel::nameRoleGroups() const
+{
+    Q_ASSERT(!m_itemData.isEmpty());
+
+    const int maxIndex = count() - 1;
+    QList<QPair<int, QVariant>> groups;
+
+    ItemGroupInfo groupInfo;
+    for (int i = 0; i <= maxIndex; ++i) {
+        if (isChildItem(i)) {
+            continue;
+        }
+
+        ItemGroupInfo newGroupInfo = nameRoleGroup(m_itemData.at(i));
+
+        if (newGroupInfo != groupInfo) {
+            groupInfo = newGroupInfo;
+            groups.append(QPair<int, QVariant>(i, newGroupInfo.text));
         }
     }
+    return groups;
+}
+
+QList<QPair<int, QVariant>> KFileItemModel::sizeRoleGroups() const
+{
+    Q_ASSERT(!m_itemData.isEmpty());
+
+    const int maxIndex = count() - 1;
+    QList<QPair<int, QVariant>> groups;
+
+    ItemGroupInfo groupInfo;
+    for (int i = 0; i <= maxIndex; ++i) {
+        if (isChildItem(i)) {
+            continue;
+        }
 
+        ItemGroupInfo newGroupInfo = sizeRoleGroup(m_itemData.at(i));
+
+        if (newGroupInfo != groupInfo) {
+            groupInfo = newGroupInfo;
+            groups.append(QPair<int, QVariant>(i, newGroupInfo.text));
+        }
+    }
     return groups;
 }
 
-QList<QPair<int, QVariant> > KFileItemModel::ratingRoleGroups() const
+KFileItemModel::ItemGroupInfo KFileItemModel::typeRoleGroup(const ItemData *itemData) const
+{
+    int priority = 0;
+    if (itemData->item.isDir() && m_sortDirsFirst) {
+        // Ensure folders stay first regardless of grouping order
+        if (groupOrder() == Qt::AscendingOrder) {
+            priority = -1;
+        } else {
+            priority = 1;
+        }
+    }
+    return {priority, itemData->values.value("type").toString()};
+}
+
+QList<QPair<int, QVariant>> KFileItemModel::timeRoleGroups(const std::function<QDateTime(const ItemData *)> &fileTimeCb) const
 {
     Q_ASSERT(!m_itemData.isEmpty());
 
     const int maxIndex = count() - 1;
-    QList<QPair<int, QVariant> > groups;
+    QList<QPair<int, QVariant>> groups;
 
-    int groupValue = -1;
+    ItemGroupInfo groupInfo;
     for (int i = 0; i <= maxIndex; ++i) {
         if (isChildItem(i)) {
             continue;
         }
-        const int newGroupValue = m_itemData.at(i)->values.value("rating", 0).toInt();
-        if (newGroupValue != groupValue) {
-            groupValue = newGroupValue;
-            groups.append(QPair<int, QVariant>(i, newGroupValue));
+
+        ItemGroupInfo newGroupInfo = timeRoleGroup(fileTimeCb, m_itemData.at(i));
+
+        if (newGroupInfo != groupInfo) {
+            groupInfo = newGroupInfo;
+            groups.append(QPair<int, QVariant>(i, newGroupInfo.text));
         }
     }
+    return groups;
+}
+
+QList<QPair<int, QVariant>> KFileItemModel::permissionRoleGroups() const
+{
+    Q_ASSERT(!m_itemData.isEmpty());
 
+    const int maxIndex = count() - 1;
+    QList<QPair<int, QVariant>> groups;
+
+    ItemGroupInfo groupInfo;
+    for (int i = 0; i <= maxIndex; ++i) {
+        if (isChildItem(i)) {
+            continue;
+        }
+
+        ItemGroupInfo newGroupInfo = permissionRoleGroup(m_itemData.at(i));
+
+        if (newGroupInfo != groupInfo) {
+            groupInfo = newGroupInfo;
+            groups.append(QPair<int, QVariant>(i, newGroupInfo.text));
+        }
+    }
     return groups;
 }
 
-QList<QPair<int, QVariant> > KFileItemModel::genericStringRoleGroups(const QByteArray& role) const
+QList<QPair<int, QVariant>> KFileItemModel::ratingRoleGroups() const
 {
     Q_ASSERT(!m_itemData.isEmpty());
 
     const int maxIndex = count() - 1;
-    QList<QPair<int, QVariant> > groups;
+    QList<QPair<int, QVariant>> groups;
 
-    bool isFirstGroupValue = true;
-    QString groupValue;
+    ItemGroupInfo groupInfo;
     for (int i = 0; i <= maxIndex; ++i) {
         if (isChildItem(i)) {
             continue;
         }
-        const QString newGroupValue = m_itemData.at(i)->values.value(role).toString();
-        if (newGroupValue != groupValue || isFirstGroupValue) {
-            groupValue = newGroupValue;
-            groups.append(QPair<int, QVariant>(i, newGroupValue));
-            isFirstGroupValue = false;
+
+        ItemGroupInfo newGroupInfo = ratingRoleGroup(m_itemData.at(i));
+
+        if (newGroupInfo != groupInfo) {
+            groupInfo = newGroupInfo;
+            // Using the numeric representation because Dolphin has a special
+            // case for drawing stars.
+            groups.append(QPair<int, QVariant>(i, newGroupInfo.comparable));
         }
     }
+    return groups;
+}
+
+QList<QPair<int, QVariant>> KFileItemModel::genericStringRoleGroups(const QByteArray &role) const
+{
+    Q_ASSERT(!m_itemData.isEmpty());
+
+    const int maxIndex = count() - 1;
+    QList<QPair<int, QVariant>> groups;
+
+    ItemGroupInfo groupInfo;
+    for (int i = 0; i <= maxIndex; ++i) {
+        if (isChildItem(i)) {
+            continue;
+        }
+
+        ItemGroupInfo newGroupInfo = genericStringRoleGroup(role, m_itemData.at(i));
 
+        if (newGroupInfo != groupInfo) {
+            groupInfo = newGroupInfo;
+            groups.append(QPair<int, QVariant>(i, newGroupInfo.text));
+        }
+    }
     return groups;
 }
 
@@ -2335,54 +3090,62 @@ void KFileItemModel::emitSortProgress(int resolvedCount)
     }
 }
 
-const KFileItemModel::RoleInfoMap* KFileItemModel::rolesInfoMap(int& count)
+const KFileItemModel::RoleInfoMap *KFileItemModel::rolesInfoMap(int &count)
 {
     static const RoleInfoMap rolesInfoMap[] = {
-    //  |         role           |        roleType        |                role translation                     |            group translation               | requires Baloo | requires indexer
-        { nullptr,               NoRole,                  nullptr, nullptr,                                     nullptr, nullptr,                            false,           false },
-        { "text",                NameRole,                I18NC_NOOP("@label", "Name"),                 nullptr, nullptr,                            false,           false },
-        { "size",                SizeRole,                I18NC_NOOP("@label", "Size"),                 nullptr, nullptr,                            false,           false },
-        { "modificationtime",    ModificationTimeRole,    I18NC_NOOP("@label", "Modified"),             nullptr, nullptr,                            false,           false },
-        { "creationtime",        CreationTimeRole,        I18NC_NOOP("@label", "Created"),              nullptr, nullptr,                            false,           false },
-        { "accesstime",          AccessTimeRole,          I18NC_NOOP("@label", "Accessed"),             nullptr, nullptr,                            false,           false },
-        { "type",                TypeRole,                I18NC_NOOP("@label", "Type"),                 nullptr, nullptr,                            false,           false },
-        { "rating",              RatingRole,              I18NC_NOOP("@label", "Rating"),               nullptr, nullptr,                            true,            false },
-        { "tags",                TagsRole,                I18NC_NOOP("@label", "Tags"),                 nullptr, nullptr,                            true,            false },
-        { "comment",             CommentRole,             I18NC_NOOP("@label", "Comment"),              nullptr, nullptr,                            true,            false },
-        { "title",               TitleRole,               I18NC_NOOP("@label", "Title"),                I18NC_NOOP("@label", "Document"),    true,            true  },
-        { "wordCount",           WordCountRole,           I18NC_NOOP("@label", "Word Count"),           I18NC_NOOP("@label", "Document"),    true,            true  },
-        { "lineCount",           LineCountRole,           I18NC_NOOP("@label", "Line Count"),           I18NC_NOOP("@label", "Document"),    true,            true  },
-        { "imageDateTime",       ImageDateTimeRole,       I18NC_NOOP("@label", "Date Photographed"),    I18NC_NOOP("@label", "Image"),       true,            true  },
-        { "width",               WidthRole,               I18NC_NOOP("@label", "Width"),                I18NC_NOOP("@label", "Image"),       true,            true  },
-        { "height",              HeightRole,              I18NC_NOOP("@label", "Height"),               I18NC_NOOP("@label", "Image"),       true,            true  },
-        { "orientation",         OrientationRole,         I18NC_NOOP("@label", "Orientation"),          I18NC_NOOP("@label", "Image"),       true,            true  },
-        { "artist",              ArtistRole,              I18NC_NOOP("@label", "Artist"),               I18NC_NOOP("@label", "Audio"),       true,            true  },
-        { "genre",               GenreRole,               I18NC_NOOP("@label", "Genre"),                I18NC_NOOP("@label", "Audio"),       true,            true  },
-        { "album",               AlbumRole,               I18NC_NOOP("@label", "Album"),                I18NC_NOOP("@label", "Audio"),       true,            true  },
-        { "duration",            DurationRole,            I18NC_NOOP("@label", "Duration"),             I18NC_NOOP("@label", "Audio"),       true,            true  },
-        { "bitrate",             BitrateRole,             I18NC_NOOP("@label", "Bitrate"),              I18NC_NOOP("@label", "Audio"),       true,            true  },
-        { "track",               TrackRole,               I18NC_NOOP("@label", "Track"),                I18NC_NOOP("@label", "Audio"),       true,            true  },
-        { "releaseYear",         ReleaseYearRole,         I18NC_NOOP("@label", "Release Year"),         I18NC_NOOP("@label", "Audio"),       true,            true  },
-        { "aspectRatio",         AspectRatioRole,         I18NC_NOOP("@label", "Aspect Ratio"),         I18NC_NOOP("@label", "Video"),       true,            true  },
-        { "frameRate",           FrameRateRole,           I18NC_NOOP("@label", "Frame Rate"),           I18NC_NOOP("@label", "Video"),       true,            true  },
-        { "path",                PathRole,                I18NC_NOOP("@label", "Path"),                 I18NC_NOOP("@label", "Other"),       false,           false },
-        { "deletiontime",        DeletionTimeRole,        I18NC_NOOP("@label", "Deletion Time"),        I18NC_NOOP("@label", "Other"),       false,           false },
-        { "destination",         DestinationRole,         I18NC_NOOP("@label", "Link Destination"),     I18NC_NOOP("@label", "Other"),       false,           false },
-        { "originUrl",           OriginUrlRole,           I18NC_NOOP("@label", "Downloaded From"),      I18NC_NOOP("@label", "Other"),       true,            false },
-        { "permissions",         PermissionsRole,         I18NC_NOOP("@label", "Permissions"),          I18NC_NOOP("@label", "Other"),       false,           false },
-        { "owner",               OwnerRole,               I18NC_NOOP("@label", "Owner"),                I18NC_NOOP("@label", "Other"),       false,           false },
-        { "group",               GroupRole,               I18NC_NOOP("@label", "User Group"),           I18NC_NOOP("@label", "Other"),       false,           false },
+        // clang-format off
+    //  |         role           |        roleType        |                role translation          |         group translation                                        | requires Baloo | requires indexer
+        { nullptr,               NoRole,                  kli18nc("@label", "None"),                 KLazyLocalizedString(),        KLazyLocalizedString(),                    false,           false },
+        { "text",                NameRole,                kli18nc("@label", "Name"),                 KLazyLocalizedString(),        KLazyLocalizedString(),                    false,           false },
+        { "size",                SizeRole,                kli18nc("@label", "Size"),                 KLazyLocalizedString(),        KLazyLocalizedString(),                    false,           false },
+        { "modificationtime",    ModificationTimeRole,    kli18nc("@label", "Modified"),             KLazyLocalizedString(),        kli18nc("@tooltip", "The date format can be selected in settings."),                    false,           false },
+        { "creationtime",        CreationTimeRole,        kli18nc("@label", "Created"),              KLazyLocalizedString(),        kli18nc("@tooltip", "The date format can be selected in settings."),                    false,           false },
+        { "accesstime",          AccessTimeRole,          kli18nc("@label", "Accessed"),             KLazyLocalizedString(),        kli18nc("@tooltip", "The date format can be selected in settings."),                    false,           false },
+        { "type",                TypeRole,                kli18nc("@label", "Type"),                 KLazyLocalizedString(),        KLazyLocalizedString(),                    false,           false },
+        { "rating",              RatingRole,              kli18nc("@label", "Rating"),               KLazyLocalizedString(),        KLazyLocalizedString(),                    true,            false },
+        { "tags",                TagsRole,                kli18nc("@label", "Tags"),                 KLazyLocalizedString(),        KLazyLocalizedString(),                    true,            false },
+        { "comment",             CommentRole,             kli18nc("@label", "Comment"),              KLazyLocalizedString(),        KLazyLocalizedString(),                    true,            false },
+        { "title",               TitleRole,               kli18nc("@label", "Title"),                kli18nc("@label", "Document"), KLazyLocalizedString(),                    true,            true  },
+        { "author",              AuthorRole,              kli18nc("@label", "Author"),               kli18nc("@label", "Document"), KLazyLocalizedString(),                    true,            true  },
+        { "publisher",           PublisherRole,           kli18nc("@label", "Publisher"),            kli18nc("@label", "Document"), KLazyLocalizedString(),                    true,            true  },
+        { "pageCount",           PageCountRole,           kli18nc("@label", "Page Count"),           kli18nc("@label", "Document"), KLazyLocalizedString(),                    true,            true  },
+        { "wordCount",           WordCountRole,           kli18nc("@label", "Word Count"),           kli18nc("@label", "Document"), KLazyLocalizedString(),                    true,            true  },
+        { "lineCount",           LineCountRole,           kli18nc("@label", "Line Count"),           kli18nc("@label", "Document"), KLazyLocalizedString(),                    true,            true  },
+        { "imageDateTime",       ImageDateTimeRole,       kli18nc("@label", "Date Photographed"),    kli18nc("@label", "Image"),    KLazyLocalizedString(),                    true,            true  },
+        { "dimensions",          DimensionsRole,          kli18nc("@label width x height", "Dimensions"), kli18nc("@label", "Image"), KLazyLocalizedString(),                  true,            true  },
+        { "width",               WidthRole,               kli18nc("@label", "Width"),                kli18nc("@label", "Image"),    KLazyLocalizedString(),                    true,            true  },
+        { "height",              HeightRole,              kli18nc("@label", "Height"),               kli18nc("@label", "Image"),    KLazyLocalizedString(),                    true,            true  },
+        { "orientation",         OrientationRole,         kli18nc("@label", "Orientation"),          kli18nc("@label", "Image"),    KLazyLocalizedString(),                    true,            true  },
+        { "artist",              ArtistRole,              kli18nc("@label", "Artist"),               kli18nc("@label", "Audio"),    KLazyLocalizedString(),                    true,            true  },
+        { "genre",               GenreRole,               kli18nc("@label", "Genre"),                kli18nc("@label", "Audio"),    KLazyLocalizedString(),                    true,            true  },
+        { "album",               AlbumRole,               kli18nc("@label", "Album"),                kli18nc("@label", "Audio"),    KLazyLocalizedString(),                    true,            true  },
+        { "duration",            DurationRole,            kli18nc("@label", "Duration"),             kli18nc("@label", "Audio"),    KLazyLocalizedString(),                    true,            true  },
+        { "bitrate",             BitrateRole,             kli18nc("@label", "Bitrate"),              kli18nc("@label", "Audio"),    KLazyLocalizedString(),                    true,            true  },
+        { "track",               TrackRole,               kli18nc("@label", "Track"),                kli18nc("@label", "Audio"),    KLazyLocalizedString(),                    true,            true  },
+        { "releaseYear",         ReleaseYearRole,         kli18nc("@label", "Release Year"),         kli18nc("@label", "Audio"),    KLazyLocalizedString(),                    true,            true  },
+        { "aspectRatio",         AspectRatioRole,         kli18nc("@label", "Aspect Ratio"),         kli18nc("@label", "Video"),    KLazyLocalizedString(),                    true,            true  },
+        { "frameRate",           FrameRateRole,           kli18nc("@label", "Frame Rate"),           kli18nc("@label", "Video"),    KLazyLocalizedString(),                    true,            true  },
+        { "duration",            DurationRole,            kli18nc("@label", "Duration"),             kli18nc("@label", "Video"),    KLazyLocalizedString(),                    true,            true  },
+        { "path",                PathRole,                kli18nc("@label", "Path"),                 kli18nc("@label", "Other"),    KLazyLocalizedString(),                    false,           false },
+        { "extension",           ExtensionRole,           kli18nc("@label", "File Extension"),       kli18nc("@label", "Other"),    KLazyLocalizedString(),                    false,           false },
+        { "deletiontime",        DeletionTimeRole,        kli18nc("@label", "Deletion Time"),        kli18nc("@label", "Other"),    KLazyLocalizedString(),                    false,           false },
+        { "destination",         DestinationRole,         kli18nc("@label", "Link Destination"),     kli18nc("@label", "Other"),    KLazyLocalizedString(),                    false,           false },
+        { "originUrl",           OriginUrlRole,           kli18nc("@label", "Downloaded From"),      kli18nc("@label", "Other"),    KLazyLocalizedString(),                    true,            false },
+        { "permissions",         PermissionsRole,         kli18nc("@label", "Permissions"),          kli18nc("@label", "Other"),    kli18nc("@tooltip", "The permission format can be changed in settings. Options are Symbolic, Numeric (Octal) or Combined formats"),        false,           false },
+        { "owner",               OwnerRole,               kli18nc("@label", "Owner"),                kli18nc("@label", "Other"),    KLazyLocalizedString(),                    false,           false },
+        { "group",               GroupRole,               kli18nc("@label", "User Group"),           kli18nc("@label", "Other"),    KLazyLocalizedString(),                    false,           false },
     };
+    // clang-format on
 
     count = sizeof(rolesInfoMap) / sizeof(RoleInfoMap);
     return rolesInfoMap;
 }
 
-void KFileItemModel::determineMimeTypes(const KFileItemList& items, int timeout)
+void KFileItemModel::determineMimeTypes(const KFileItemList &items, int timeout)
 {
     QElapsedTimer timer;
     timer.start();
-    for (const KFileItem& item : items) {
+    for (const KFileItem &item : items) {
         // Only determine mime types for files here. For directories,
         // KFileItem::determineMimeType() reads the .directory file inside to
         // load the icon, but this is not necessary at all if we just need the
@@ -2400,7 +3163,7 @@ void KFileItemModel::determineMimeTypes(const KFileItemList& items, int timeout)
     }
 }
 
-QByteArray KFileItemModel::sharedValue(const QByteArray& value)
+QByteArray KFileItemModel::sharedValue(const QByteArray &value)
 {
     static QSet<QByteArray> pool;
     const QSet<QByteArray>::const_iterator it = pool.constFind(value);
@@ -2437,14 +3200,13 @@ bool KFileItemModel::isConsistent() const
 
         // Check if the items are sorted correctly.
         if (i > 0 && !lessThan(m_itemData.at(i - 1), m_itemData.at(i), m_collator)) {
-            qCWarning(DolphinDebug) << "The order of items" << i - 1 << "and" << i << "is wrong:"
-                << fileItem(i - 1) << fileItem(i);
+            qCWarning(DolphinDebug) << "The order of items" << i - 1 << "and" << i << "is wrong:" << fileItem(i - 1) << fileItem(i);
             return false;
         }
 
         // Check if all parent-child relationships are consistent.
-        const ItemData* data = m_itemData.at(i);
-        const ItemData* parent = data->parent;
+        const ItemData *data = m_itemData.at(i);
+        const ItemData *parent = data->parent;
         if (parent) {
             if (expandedParentsCount(data) != expandedParentsCount(parent) + 1) {
                 qCWarning(DolphinDebug) << "expandedParentsCount is inconsistent for parent" << parent->item << "and child" << data->item;
@@ -2453,7 +3215,8 @@ bool KFileItemModel::isConsistent() const
 
             const int parentIndex = index(parent->item);
             if (parentIndex >= i) {
-                qCWarning(DolphinDebug) << "Index" << parentIndex << "of parent" << parent->item << "is not smaller than index" << i << "of child" << data->item;
+                qCWarning(DolphinDebug) << "Index" << parentIndex << "of parent" << parent->item << "is not smaller than index" << i << "of child"
+                                        << data->item;
                 return false;
             }
         }
@@ -2461,3 +3224,18 @@ bool KFileItemModel::isConsistent() const
 
     return true;
 }
+
+void KFileItemModel::slotListerError(KIO::Job *job)
+{
+    const int jobError = job->error();
+    if (jobError == KIO::ERR_IS_FILE) {
+        if (auto *listJob = qobject_cast<KIO::ListJob *>(job)) {
+            Q_EMIT urlIsFileError(listJob->url());
+        }
+    } else {
+        const QString errorString = job->errorString();
+        Q_EMIT errorMessage(!errorString.isEmpty() ? errorString : i18nc("@info:status", "Unknown error."), jobError);
+    }
+}
+
+#include "moc_kfileitemmodel.cpp"