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[dolphin.git] / src / kitemviews / kfileitemmodel.cpp

diff --git a/src/kitemviews/kfileitemmodel.cpp b/src/kitemviews/kfileitemmodel.cpp
index 70e92eaac1990e56b0810460edbfcb38e1da1ca3..14de9697ba9972263c6143f50c79fa1d22abf97d 100644 (file)
--- a/src/kitemviews/kfileitemmodel.cpp
+++ b/src/kitemviews/kfileitemmodel.cpp
@@ -1,90 +1,100 @@
-/***************************************************************************
- *   Copyright (C) 2011 by Peter Penz <peter.penz19@gmail.com>             *
- *                                                                         *
- *   This program is free software; you can redistribute it and/or modify  *
- *   it under the terms of the GNU General Public License as published by  *
- *   the Free Software Foundation; either version 2 of the License, or     *
- *   (at your option) any later version.                                   *
- *                                                                         *
- *   This program is distributed in the hope that it will be useful,       *
- *   but WITHOUT ANY WARRANTY; without even the implied warranty of        *
- *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the         *
- *   GNU General Public License for more details.                          *
- *                                                                         *
- *   You should have received a copy of the GNU General Public License     *
- *   along with this program; if not, write to the                         *
- *   Free Software Foundation, Inc.,                                       *
- *   51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA            *
- ***************************************************************************/
+/*
+ * SPDX-FileCopyrightText: 2011 Peter Penz <peter.penz19@gmail.com>
+ * SPDX-FileCopyrightText: 2013 Frank Reininghaus <frank78ac@googlemail.com>
+ * SPDX-FileCopyrightText: 2013 Emmanuel Pescosta <emmanuelpescosta099@gmail.com>
+ *
+ * SPDX-License-Identifier: GPL-2.0-or-later
+ */

 
 #include "kfileitemmodel.h"
 
 
 #include "kfileitemmodel.h"
 

+#include "dolphin_detailsmodesettings.h"
+#include "dolphin_generalsettings.h"
+#include "dolphindebug.h"
+#include "private/kfileitemmodelsortalgorithm.h"
+

 #include <KDirLister>
 #include <KDirLister>

-#include <KDirModel>
-#include <KLocale>
-#include <KStringHandler>
-#include <KDebug>
+#include <KIO/Job>
+#include <KLocalizedString>
+#include <KUrlMimeData>
+#include <kio_version.h>

 
 

+#include <QElapsedTimer>
+#include <QIcon>

 #include <QMimeData>
 #include <QMimeData>

+#include <QMimeDatabase>
+#include <QRecursiveMutex>

 #include <QTimer>
 #include <QTimer>

+#include <QWidget>
+#include <algorithm>
+#include <klazylocalizedstring.h>
+
+Q_GLOBAL_STATIC(QRecursiveMutex, s_collatorMutex)

 
 // #define KFILEITEMMODEL_DEBUG
 
 
 // #define KFILEITEMMODEL_DEBUG
 

-KFileItemModel::KFileItemModel(KDirLister* dirLister, QObject* parent) :
-    KItemModelBase("name", parent),
-    m_dirLister(dirLister),
-    m_naturalSorting(true),
-    m_sortFoldersFirst(true),
-    m_sortRole(NameRole),
-    m_roles(),
-    m_caseSensitivity(Qt::CaseInsensitive),
-    m_itemData(),
-    m_items(),
-    m_filter(),
-    m_filteredItems(),
-    m_requestRole(),
-    m_minimumUpdateIntervalTimer(0),
-    m_maximumUpdateIntervalTimer(0),
-    m_resortAllItemsTimer(0),
-    m_pendingItemsToInsert(),
-    m_pendingEmitLoadingCompleted(false),
-    m_groups(),
-    m_rootExpansionLevel(UninitializedRootExpansionLevel),
-    m_expandedUrls(),
-    m_urlsToExpand()
-{
+KFileItemModel::KFileItemModel(QObject *parent)
+    : KItemModelBase("text", parent)
+    , m_dirLister(nullptr)
+    , m_sortDirsFirst(true)
+    , m_sortHiddenLast(false)
+    , 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()
+{
+    m_collator.setNumericMode(true);
+
+    loadSortingSettings();
+
+    m_dirLister = new KDirLister(this);
+    m_dirLister->setAutoErrorHandlingEnabled(false);
+    m_dirLister->setDelayedMimeTypes(true);
+
+    const QWidget *parentWidget = qobject_cast<QWidget *>(parent);
+    if (parentWidget) {
+        m_dirLister->setMainWindow(parentWidget->window());
+    }
+
+    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);
+

     // Apply default roles that should be determined
     resetRoles();
     m_requestRole[NameRole] = true;
     m_requestRole[IsDirRole] = true;
     // Apply default roles that should be determined
     resetRoles();
     m_requestRole[NameRole] = true;
     m_requestRole[IsDirRole] = true;

-    m_roles.insert("name");
+    m_requestRole[IsLinkRole] = true;
+    m_roles.insert("text");

     m_roles.insert("isDir");
     m_roles.insert("isDir");

-
-    Q_ASSERT(dirLister);
-
-    connect(dirLister, SIGNAL(canceled()), this, SLOT(slotCanceled()));
-    connect(dirLister, SIGNAL(completed()), this, SLOT(slotCompleted()));
-    connect(dirLister, SIGNAL(newItems(KFileItemList)), this, SLOT(slotNewItems(KFileItemList)));
-    connect(dirLister, SIGNAL(itemsDeleted(KFileItemList)), this, SLOT(slotItemsDeleted(KFileItemList)));
-    connect(dirLister, SIGNAL(refreshItems(QList<QPair<KFileItem,KFileItem> >)), this, SLOT(slotRefreshItems(QList<QPair<KFileItem,KFileItem> >)));
-    connect(dirLister, SIGNAL(clear()), this, SLOT(slotClear()));
-    connect(dirLister, SIGNAL(clear(KUrl)), this, SLOT(slotClear(KUrl)));
-
-    // Although the layout engine of KItemListView is fast it is very inefficient to e.g.
-    // emit 50 itemsInserted()-signals each 100 ms. m_minimumUpdateIntervalTimer assures that updates
-    // are done in 1 second intervals for equal operations.
-    m_minimumUpdateIntervalTimer = new QTimer(this);
-    m_minimumUpdateIntervalTimer->setInterval(1000);
-    m_minimumUpdateIntervalTimer->setSingleShot(true);
-    connect(m_minimumUpdateIntervalTimer, SIGNAL(timeout()), this, SLOT(dispatchPendingItemsToInsert()));
+    m_roles.insert("isLink");
+    m_roles.insert("isHidden");

 
     // For slow KIO-slaves like used for searching it makes sense to show results periodically even
     // before the completed() or canceled() signal has been emitted.
     m_maximumUpdateIntervalTimer = new QTimer(this);
     m_maximumUpdateIntervalTimer->setInterval(2000);
     m_maximumUpdateIntervalTimer->setSingleShot(true);
 
     // For slow KIO-slaves like used for searching it makes sense to show results periodically even
     // before the completed() or canceled() signal has been emitted.
     m_maximumUpdateIntervalTimer = new QTimer(this);
     m_maximumUpdateIntervalTimer->setInterval(2000);
     m_maximumUpdateIntervalTimer->setSingleShot(true);

-    connect(m_maximumUpdateIntervalTimer, SIGNAL(timeout()), this, SLOT(dispatchPendingItemsToInsert()));
-    
+    connect(m_maximumUpdateIntervalTimer, &QTimer::timeout, this, &KFileItemModel::dispatchPendingItemsToInsert);
+

     // When changing the value of an item which represents the sort-role a resorting must be
     // triggered. Especially in combination with KFileItemModelRolesUpdater this might be done
     // for a lot of items within a quite small timeslot. To prevent expensive resortings the
     // When changing the value of an item which represents the sort-role a resorting must be
     // triggered. Especially in combination with KFileItemModelRolesUpdater this might be done
     // for a lot of items within a quite small timeslot. To prevent expensive resortings the


@@ -92,15 +102,43 @@ KFileItemModel::KFileItemModel(KDirLister* dirLister, QObject* parent) :
     m_resortAllItemsTimer = new QTimer(this);
     m_resortAllItemsTimer->setInterval(500);
     m_resortAllItemsTimer->setSingleShot(true);
     m_resortAllItemsTimer = new QTimer(this);
     m_resortAllItemsTimer->setInterval(500);
     m_resortAllItemsTimer->setSingleShot(true);

-    connect(m_resortAllItemsTimer, SIGNAL(timeout()), this, SLOT(resortAllItems()));
+    connect(m_resortAllItemsTimer, &QTimer::timeout, this, &KFileItemModel::resortAllItems);

 
 

-    Q_ASSERT(m_minimumUpdateIntervalTimer->interval() <= m_maximumUpdateIntervalTimer->interval());
+    connect(GeneralSettings::self(), &GeneralSettings::sortingChoiceChanged, this, &KFileItemModel::slotSortingChoiceChanged);

 }
 
 KFileItemModel::~KFileItemModel()
 {
     qDeleteAll(m_itemData);
 }
 
 KFileItemModel::~KFileItemModel()
 {
     qDeleteAll(m_itemData);

-    m_itemData.clear();
+    qDeleteAll(m_filteredItems);
+    qDeleteAll(m_pendingItemsToInsert);
+}
+
+void KFileItemModel::loadDirectory(const QUrl &url)
+{
+    m_dirLister->openUrl(url);
+}
+
+void KFileItemModel::refreshDirectory(const QUrl &url)
+{
+    // Refresh all expanded directories first (Bug 295300)
+    QHashIterator<QUrl, QUrl> expandedDirs(m_expandedDirs);
+    while (expandedDirs.hasNext()) {
+        expandedDirs.next();
+        m_dirLister->openUrl(expandedDirs.value(), KDirLister::Reload);
+    }
+
+    m_dirLister->openUrl(url, KDirLister::Reload);
+}
+
+QUrl KFileItemModel::directory() const
+{
+    return m_dirLister->url();
+}
+
+void KFileItemModel::cancelDirectoryLoading()
+{
+    m_dirLister->stop();

 }
 
 int KFileItemModel::count() const
 }
 
 int KFileItemModel::count() const


@@ -111,25 +149,42 @@ int KFileItemModel::count() const
 QHash<QByteArray, QVariant> KFileItemModel::data(int index) const
 {
     if (index >= 0 && index < count()) {
 QHash<QByteArray, QVariant> KFileItemModel::data(int index) const
 {
     if (index >= 0 && index < count()) {

-        return m_itemData.at(index)->values;
+        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;

     }
     return QHash<QByteArray, QVariant>();
 }
 
     }
     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;
     }
 
 {
     if (index < 0 || index >= count()) {
         return false;
     }
 

-    QHash<QByteArray, QVariant> currentValues = m_itemData.at(index)->values;
+    QHash<QByteArray, QVariant> currentValues = data(index);

 
     // Determine which roles have been changed
     QSet<QByteArray> changedRoles;
     QHashIterator<QByteArray, QVariant> it(values);
     while (it.hasNext()) {
         it.next();
 
     // Determine which roles have been changed
     QSet<QByteArray> changedRoles;
     QHashIterator<QByteArray, QVariant> it(values);
     while (it.hasNext()) {
         it.next();

-        const QByteArray role = it.key();
+        const QByteArray role = sharedValue(it.key());

         const QVariant value = it.value();
 
         if (currentValues[role] != value) {
         const QVariant value = it.value();
 
         if (currentValues[role] != value) {


@@ -143,94 +198,124 @@ bool KFileItemModel::setData(int index, const QHash<QByteArray, QVariant>& value
     }
 
     m_itemData[index]->values = currentValues;
     }
 
     m_itemData[index]->values = currentValues;

-    emit itemsChanged(KItemRangeList() << KItemRange(index, 1), changedRoles);
-
-    if (changedRoles.contains(sortRole())) {
-        m_resortAllItemsTimer->start();
+    if (changedRoles.contains("text")) {
+        QUrl url = m_itemData[index]->item.url();
+        url = url.adjusted(QUrl::RemoveFilename);
+        url.setPath(url.path() + currentValues["text"].toString());
+        m_itemData[index]->item.setUrl(url);

     }
     }

-        
+
+    emitItemsChangedAndTriggerResorting(KItemRangeList() << KItemRange(index, 1), changedRoles);
+

     return true;
 }
 
     return true;
 }
 

-void KFileItemModel::setSortFoldersFirst(bool foldersFirst)
+void KFileItemModel::setSortDirectoriesFirst(bool dirsFirst)
+{
+    if (dirsFirst != m_sortDirsFirst) {
+        m_sortDirsFirst = dirsFirst;
+        resortAllItems();
+    }
+}
+
+bool KFileItemModel::sortDirectoriesFirst() const
+{
+    return m_sortDirsFirst;
+}
+
+void KFileItemModel::setSortHiddenLast(bool hiddenLast)

 {
 {

-    if (foldersFirst != m_sortFoldersFirst) {
-        m_sortFoldersFirst = foldersFirst;
+    if (hiddenLast != m_sortHiddenLast) {
+        m_sortHiddenLast = hiddenLast;

         resortAllItems();
     }
 }
 
         resortAllItems();
     }
 }
 

-bool KFileItemModel::sortFoldersFirst() const
+bool KFileItemModel::sortHiddenLast() const

 {
 {

-    return m_sortFoldersFirst;
+    return m_sortHiddenLast;

 }
 
 void KFileItemModel::setShowHiddenFiles(bool show)
 {
 }
 
 void KFileItemModel::setShowHiddenFiles(bool show)
 {

-    KDirLister* dirLister = m_dirLister.data();
-    if (dirLister) {
-        dirLister->setShowingDotFiles(show);
-        dirLister->emitChanges();
-        if (show) {
-            slotCompleted();
-        }
+#if KIO_VERSION < QT_VERSION_CHECK(5, 100, 0)
+    m_dirLister->setShowingDotFiles(show);
+#else
+    m_dirLister->setShowHiddenFiles(show);
+#endif
+    m_dirLister->emitChanges();
+    if (show) {
+        dispatchPendingItemsToInsert();

     }
 }
 
 bool KFileItemModel::showHiddenFiles() const
 {
     }
 }
 
 bool KFileItemModel::showHiddenFiles() const
 {

-    const KDirLister* dirLister = m_dirLister.data();
-    return dirLister ? dirLister->showingDotFiles() : false;
+#if KIO_VERSION < QT_VERSION_CHECK(5, 100, 0)
+    return m_dirLister->showingDotFiles();
+#else
+    return m_dirLister->showHiddenFiles();
+#endif
+}
+
+void KFileItemModel::setShowDirectoriesOnly(bool enabled)
+{
+    m_dirLister->setDirOnlyMode(enabled);

 }
 
 }
 

-QMimeData* KFileItemModel::createMimeData(const QSet<int>& indexes) const
+bool KFileItemModel::showDirectoriesOnly() const

 {
 {

-    QMimeData* data = new QMimeData();
+    return m_dirLister->dirOnlyMode();
+}
+
+QMimeData *KFileItemModel::createMimeData(const KItemSet &indexes) const
+{
+    QMimeData *data = new QMimeData();

 
     // The following code has been taken from KDirModel::mimeData()
     // (kdelibs/kio/kio/kdirmodel.cpp)
 
     // The following code has been taken from KDirModel::mimeData()
     // (kdelibs/kio/kio/kdirmodel.cpp)

-    // Copyright (C) 2006 David Faure <faure@kde.org>
-    KUrl::List urls;
-    KUrl::List mostLocalUrls;
-    bool canUseMostLocalUrls = true;
+    // SPDX-FileCopyrightText: 2006 David Faure <faure@kde.org>
+    QList<QUrl> urls;
+    QList<QUrl> mostLocalUrls;
+    const ItemData *lastAddedItem = nullptr;

 
 

-    QSetIterator<int> it(indexes);
-    while (it.hasNext()) {
-        const int index = it.next();
-        const KFileItem item = fileItem(index);
+    for (int index : indexes) {
+        const ItemData *itemData = m_itemData.at(index);
+        const ItemData *parent = itemData->parent;
+
+        while (parent && parent != lastAddedItem) {
+            parent = parent->parent;
+        }
+
+        if (parent && parent == lastAddedItem) {
+            // A parent of 'itemData' has been added already.
+            continue;
+        }
+
+        lastAddedItem = itemData;
+        const KFileItem &item = itemData->item;

         if (!item.isNull()) {
             urls << item.url();
 
             bool isLocal;
         if (!item.isNull()) {
             urls << item.url();
 
             bool isLocal;

-            mostLocalUrls << item.mostLocalUrl(isLocal);
-            if (!isLocal) {
-                canUseMostLocalUrls = false;
-            }
+            mostLocalUrls << item.mostLocalUrl(&isLocal);

         }
     }
 
         }
     }
 

-    const bool different = canUseMostLocalUrls && mostLocalUrls != urls;
-    urls = KDirModel::simplifiedUrlList(urls); // TODO: Check if we still need KDirModel for this in KDE 5.0
-    if (different) {
-        mostLocalUrls = KDirModel::simplifiedUrlList(mostLocalUrls);
-        urls.populateMimeData(mostLocalUrls, data);
-    } else {
-        urls.populateMimeData(data);
-    }
-
+    KUrlMimeData::setUrls(urls, mostLocalUrls, data);

     return data;
 }
 
     return data;
 }
 

-int KFileItemModel::indexForKeyboardSearch(const QString& text, int startFromIndex) const
+int KFileItemModel::indexForKeyboardSearch(const QString &text, int startFromIndex) const

 {
     startFromIndex = qMax(0, startFromIndex);
     for (int i = startFromIndex; i < count(); ++i) {
 {
     startFromIndex = qMax(0, startFromIndex);
     for (int i = startFromIndex; i < count(); ++i) {

-        if (data(i)["name"].toString().startsWith(text, Qt::CaseInsensitive)) {
+        if (fileItem(i).text().startsWith(text, Qt::CaseInsensitive)) {

             return i;
         }
     }
     for (int i = 0; i < startFromIndex; ++i) {
             return i;
         }
     }
     for (int i = 0; i < startFromIndex; ++i) {

-        if (data(i)["name"].toString().startsWith(text, Qt::CaseInsensitive)) {
+        if (fileItem(i).text().startsWith(text, Qt::CaseInsensitive)) {

             return i;
         }
     }
             return i;
         }
     }


@@ -240,65 +325,73 @@ int KFileItemModel::indexForKeyboardSearch(const QString& text, int startFromInd
 bool KFileItemModel::supportsDropping(int index) const
 {
     const KFileItem item = fileItem(index);
 bool KFileItemModel::supportsDropping(int index) const
 {
     const KFileItem item = fileItem(index);

-    return item.isNull() ? false : item.isDir();
+    return !item.isNull() && (item.isDir() || item.isDesktopFile());

 }
 
 }
 

-QString KFileItemModel::roleDescription(const QByteArray& role) const
+QString KFileItemModel::roleDescription(const QByteArray &role) const

 {
 {

-    QString descr;
-
-    switch (roleIndex(role)) {
-    case NameRole:           descr = i18nc("@item:intable", "Name"); break;
-    case SizeRole:           descr = i18nc("@item:intable", "Size"); break;
-    case DateRole:           descr = i18nc("@item:intable", "Date"); break;
-    case PermissionsRole:    descr = i18nc("@item:intable", "Permissions"); break;
-    case OwnerRole:          descr = i18nc("@item:intable", "Owner"); break;
-    case GroupRole:          descr = i18nc("@item:intable", "Group"); break;
-    case TypeRole:           descr = i18nc("@item:intable", "Type"); break;
-    case DestinationRole:    descr = i18nc("@item:intable", "Destination"); break;
-    case PathRole:           descr = i18nc("@item:intable", "Path"); break;
-    case CommentRole:        descr = i18nc("@item:intable", "Comment"); break;
-    case TagsRole:           descr = i18nc("@item:intable", "Tags"); break;
-    case RatingRole:         descr = i18nc("@item:intable", "Rating"); break;
-    case NoRole:             break;
-    case IsDirRole:          break;
-    case IsExpandedRole:     break;
-    case ExpansionLevelRole: break;
-    default:                 Q_ASSERT(false); break;
+    static QHash<QByteArray, QString> description;
+    if (description.isEmpty()) {
+        int count = 0;
+        const RoleInfoMap *map = rolesInfoMap(count);
+        for (int i = 0; i < count; ++i) {
+            if (map[i].roleTranslation.isEmpty()) {
+                continue;
+            }
+            description.insert(map[i].role, map[i].roleTranslation.toString());
+        }

     }
 
     }
 

-    return descr;
+    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
 {
     if (!m_itemData.isEmpty() && m_groups.isEmpty()) {
 #ifdef KFILEITEMMODEL_DEBUG
         QElapsedTimer timer;
         timer.start();
 #endif

-        switch (roleIndex(sortRole())) {
-        case NameRole:           m_groups = nameRoleGroups(); break;
-        case SizeRole:           m_groups = sizeRoleGroups(); break;
-        case DateRole:           m_groups = dateRoleGroups(); break;
-        case PermissionsRole:    m_groups = permissionRoleGroups(); break;
-        case OwnerRole:          m_groups = genericStringRoleGroups("owner"); break;
-        case GroupRole:          m_groups = genericStringRoleGroups("group"); break;
-        case TypeRole:           m_groups = genericStringRoleGroups("type"); break;
-        case DestinationRole:    m_groups = genericStringRoleGroups("destination"); break;
-        case PathRole:           m_groups = genericStringRoleGroups("path"); break;
-        case CommentRole:        m_groups = genericStringRoleGroups("comment"); break;
-        case TagsRole:           m_groups = genericStringRoleGroups("tags"); break;
-        case RatingRole:         m_groups = ratingRoleGroups(); break;
-        case NoRole:             break;
-        case IsDirRole:          break;
-        case IsExpandedRole:     break;
-        case ExpansionLevelRole: break;
-        default:                 Q_ASSERT(false); break;
+        switch (typeForRole(sortRole())) {
+        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);
+            });
+            break;
+        case CreationTimeRole:
+            m_groups = timeRoleGroups([](const ItemData *item) {
+                return item->item.time(KFileItem::CreationTime);
+            });
+            break;
+        case AccessTimeRole:
+            m_groups = timeRoleGroups([](const ItemData *item) {
+                return item->item.time(KFileItem::AccessTime);
+            });
+            break;
+        case DeletionTimeRole:
+            m_groups = timeRoleGroups([](const ItemData *item) {
+                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;

         }
 
 #ifdef KFILEITEMMODEL_DEBUG
         }
 
 #ifdef KFILEITEMMODEL_DEBUG

-        kDebug() << "[TIME] Calculating groups for" << count() << "items:" << timer.elapsed();
+        qCDebug(DolphinDebug) << "[TIME] Calculating groups for" << count() << "items:" << timer.elapsed();

 #endif
     }
 
 #endif
     }
 


@@ -314,38 +407,94 @@ KFileItem KFileItemModel::fileItem(int index) const
     return KFileItem();
 }
 
     return KFileItem();
 }
 

-KFileItem KFileItemModel::fileItem(const KUrl& url) const
+KFileItem KFileItemModel::fileItem(const QUrl &url) const

 {
 {

-    const int index = m_items.value(url, -1);
-    if (index >= 0) {
-        return m_itemData.at(index)->item;
+    const int indexForUrl = index(url);
+    if (indexForUrl >= 0) {
+        return m_itemData.at(indexForUrl)->item;

     }
     return KFileItem();
 }
 
     }
     return KFileItem();
 }
 

-int KFileItemModel::index(const KFileItem& item) const
+int KFileItemModel::index(const KFileItem &item) const

 {
 {

-    if (item.isNull()) {
-        return -1;
-    }
-
-    return m_items.value(item.url(), -1);
+    return index(item.url());

 }
 
 }
 

-int KFileItemModel::index(const KUrl& url) const
+int KFileItemModel::index(const QUrl &url) const

 {
 {

-    KUrl urlToFind = url;
-    urlToFind.adjustPath(KUrl::RemoveTrailingSlash);
-    return m_items.value(urlToFind, -1);
+    const QUrl urlToFind = url.adjusted(QUrl::StripTrailingSlash);
+
+    const int itemCount = m_itemData.count();
+    int itemsInHash = m_items.count();
+
+    int index = m_items.value(urlToFind, -1);
+    while (index < 0 && itemsInHash < itemCount) {
+        // Not all URLs are stored yet in m_items. We grow m_items until either
+        // urlToFind is found, or all URLs have been stored in m_items.
+        // Note that we do not add the URLs to m_items one by one, but in
+        // larger blocks. After each block, we check if urlToFind is in
+        // m_items. We could in principle compare urlToFind with each URL while
+        // we are going through m_itemData, but comparing two QUrls will,
+        // unlike calling qHash for the URLs, trigger a parsing of the URLs
+        // which costs both CPU cycles and memory.
+        const int blockSize = 1000;
+        const int currentBlockEnd = qMin(itemsInHash + blockSize, itemCount);
+        for (int i = itemsInHash; i < currentBlockEnd; ++i) {
+            const QUrl nextUrl = m_itemData.at(i)->item.url();
+            m_items.insert(nextUrl, i);
+        }
+
+        itemsInHash = currentBlockEnd;
+        index = m_items.value(urlToFind, -1);
+    }
+
+    if (index < 0) {
+        // The item could not be found, even though all items from m_itemData
+        // should be in m_items now. We print some diagnostic information which
+        // might help to find the cause of the problem, but only once. This
+        // prevents that obtaining and printing the debugging information
+        // wastes CPU cycles and floods the shell or .xsession-errors.
+        static bool printDebugInfo = true;
+
+        if (m_items.count() != m_itemData.count() && printDebugInfo) {
+            printDebugInfo = false;
+
+            qCWarning(DolphinDebug) << "The model is in an inconsistent state.";
+            qCWarning(DolphinDebug) << "m_items.count()    ==" << m_items.count();
+            qCWarning(DolphinDebug) << "m_itemData.count() ==" << m_itemData.count();
+
+            // Check if there are multiple items with the same URL.
+            QMultiHash<QUrl, int> indexesForUrl;
+            for (int i = 0; i < m_itemData.count(); ++i) {
+                indexesForUrl.insert(m_itemData.at(i)->item.url(), i);
+            }
+
+            const auto uniqueKeys = indexesForUrl.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());
+                        qCWarning(DolphinDebug) << "index" << it.value() << ":" << data->item;
+                        if (data->parent) {
+                            qCWarning(DolphinDebug) << "parent" << data->parent->item;
+                        }
+                        ++it;
+                    }
+                }
+            }
+        }
+    }
+
+    return index;

 }
 
 KFileItem KFileItemModel::rootItem() const
 {
 }
 
 KFileItem KFileItemModel::rootItem() const
 {

-    const KDirLister* dirLister = m_dirLister.data();
-    if (dirLister) {
-        return dirLister->rootItem();
-    }
-    return KFileItem();
+    return m_dirLister->rootItem();

 }
 
 void KFileItemModel::clear()
 }
 
 void KFileItemModel::clear()


@@ -353,13 +502,18 @@ void KFileItemModel::clear()
     slotClear();
 }
 
     slotClear();
 }
 

-void KFileItemModel::setRoles(const QSet<QByteArray>& roles)
+void KFileItemModel::setRoles(const QSet<QByteArray> &roles)

 {
 {

+    if (m_roles == roles) {
+        return;
+    }
+
+    const QSet<QByteArray> changedRoles = (roles - m_roles) + (m_roles - roles);

     m_roles = roles;
 
     if (count() > 0) {
     m_roles = roles;
 
     if (count() > 0) {

-        const bool supportedExpanding = m_requestRole[ExpansionLevelRole];
-        const bool willSupportExpanding = roles.contains("expansionLevel");
+        const bool supportedExpanding = m_requestRole[ExpandedParentsCountRole];
+        const bool willSupportExpanding = roles.contains("expandedParentsCount");

         if (supportedExpanding && !willSupportExpanding) {
             // No expanding is supported anymore. Take care to delete all items that have an expansion level
             // that is not 0 (and hence are part of an expanded item).
         if (supportedExpanding && !willSupportExpanding) {
             // No expanding is supported anymore. Take care to delete all items that have an expansion level
             // that is not 0 (and hence are part of an expanded item).


@@ -367,23 +521,32 @@ void KFileItemModel::setRoles(const QSet<QByteArray>& roles)
         }
     }
 
         }
     }
 

+    m_groups.clear();

     resetRoles();
 
     QSetIterator<QByteArray> it(roles);
     while (it.hasNext()) {
     resetRoles();
 
     QSetIterator<QByteArray> it(roles);
     while (it.hasNext()) {

-        const QByteArray& role = it.next();
-        m_requestRole[roleIndex(role)] = true;
+        const QByteArray &role = it.next();
+        m_requestRole[typeForRole(role)] = true;

     }
 
     if (count() > 0) {
         // Update m_data with the changed requested roles
         const int maxIndex = count() - 1;
         for (int i = 0; i <= maxIndex; ++i) {
     }
 
     if (count() > 0) {
         // Update m_data with the changed requested roles
         const int maxIndex = count() - 1;
         for (int i = 0; i <= maxIndex; ++i) {

-            m_itemData[i]->values = retrieveData(m_itemData.at(i)->item);
+            m_itemData[i]->values = retrieveData(m_itemData.at(i)->item, m_itemData.at(i)->parent);

         }
 
         }
 

-        kWarning() << "TODO: Emitting itemsChanged() with no information what has changed!";
-        emit itemsChanged(KItemRangeList() << KItemRange(0, count()), QSet<QByteArray>());
+        Q_EMIT itemsChanged(KItemRangeList() << KItemRange(0, count()), changedRoles);
+    }
+
+    // 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();
+    while (filteredIt != filteredEnd) {
+        (*filteredIt)->values.clear();
+        ++filteredIt;

     }
 }
 
     }
 }
 


@@ -399,39 +562,71 @@ bool KFileItemModel::setExpanded(int index, bool expanded)
     }
 
     QHash<QByteArray, QVariant> values;
     }
 
     QHash<QByteArray, QVariant> values;

-    values.insert("isExpanded", expanded);
+    values.insert(sharedValue("isExpanded"), expanded);

     if (!setData(index, values)) {
         return false;
     }
 
     if (!setData(index, values)) {
         return false;
     }
 

-    KDirLister* dirLister = m_dirLister.data();
-    const KUrl url = m_itemData.at(index)->item.url();
+    const KFileItem item = m_itemData.at(index)->item;
+    const QUrl url = item.url();
+    const QUrl targetUrl = item.targetUrl();

     if (expanded) {
     if (expanded) {

-        m_expandedUrls.insert(url);
+        m_expandedDirs.insert(targetUrl, url);
+        m_dirLister->openUrl(url, KDirLister::Keep);

 
 

-        if (dirLister) {
-            dirLister->openUrl(url, KDirLister::Keep);
-            return true;
+        const QVariantList previouslyExpandedChildren = m_itemData.at(index)->values.value("previouslyExpandedChildren").value<QVariantList>();
+        for (const QVariant &var : previouslyExpandedChildren) {
+            m_urlsToExpand.insert(var.toUrl());

         }
     } else {
         }
     } else {

-        m_expandedUrls.remove(url);
+        // Note that there might be (indirect) children of the folder which is to be collapsed in
+        // m_pendingItemsToInsert. To prevent that they will be inserted into the model later,
+        // possibly without a parent, which might result in a crash, we insert all pending items
+        // right now. All new items which would be without a parent will then be removed.
+        dispatchPendingItemsToInsert();

 
 

-        if (dirLister) {
-            dirLister->stop(url);
+        // Check if the index of the collapsed folder has changed. If that is the case, then items
+        // were inserted before the collapsed folder, and its index needs to be updated.
+        if (m_itemData.at(index)->item != item) {
+            index = this->index(item);

         }
 
         }
 

-        KFileItemList itemsToRemove;
-        const int expansionLevel = data(index)["expansionLevel"].toInt();
-        ++index;
-        while (index < count() && data(index)["expansionLevel"].toInt() > expansionLevel) {
-            itemsToRemove.append(m_itemData.at(index)->item);
-            ++index;
+        m_expandedDirs.remove(targetUrl);
+        m_dirLister->stop(url);
+#if KIO_VERSION >= QT_VERSION_CHECK(5, 92, 0)
+        m_dirLister->forgetDirs(url);
+#endif
+
+        const int parentLevel = expandedParentsCount(index);
+        const int itemCount = m_itemData.count();
+        const int firstChildIndex = index + 1;
+
+        QVariantList expandedChildren;
+
+        int childIndex = firstChildIndex;
+        while (childIndex < itemCount && expandedParentsCount(childIndex) > parentLevel) {
+            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
+#if KIO_VERSION >= QT_VERSION_CHECK(5, 92, 0)
+                m_dirLister->forgetDirs(url);
+#endif
+                expandedChildren.append(targetUrl);
+            }
+            ++childIndex;

         }
         }

-        removeItems(itemsToRemove);
-        return true;
+        const int childrenCount = childIndex - firstChildIndex;
+
+        removeFilteredChildren(KItemRangeList() << KItemRange(index, 1 + childrenCount));
+        removeItems(KItemRangeList() << KItemRange(firstChildIndex, childrenCount), DeleteItemData);
+
+        m_itemData.at(index)->values.insert("previouslyExpandedChildren", expandedChildren);

     }
 
     }
 

-    return false;
+    return true;

 }
 
 bool KFileItemModel::isExpanded(int index) const
 }
 
 bool KFileItemModel::isExpanded(int index) const


@@ -445,50 +640,62 @@ bool KFileItemModel::isExpanded(int index) const
 bool KFileItemModel::isExpandable(int index) const
 {
     if (index >= 0 && index < count()) {
 bool KFileItemModel::isExpandable(int index) const
 {
     if (index >= 0 && index < count()) {

-        return m_itemData.at(index)->values.value("isExpandable").toBool();
+        // Call data (instead of accessing m_itemData directly)
+        // to ensure that the value is initialized.
+        return data(index).value("isExpandable").toBool();

     }
     return false;
 }
 
     }
     return false;
 }
 

-QSet<KUrl> KFileItemModel::expandedUrls() const
+int KFileItemModel::expandedParentsCount(int index) const

 {
 {

-    return m_expandedUrls;
+    if (index >= 0 && index < count()) {
+        return expandedParentsCount(m_itemData.at(index));
+    }
+    return 0;

 }
 
 }
 

-void KFileItemModel::restoreExpandedUrls(const QSet<KUrl>& urls)
+QSet<QUrl> KFileItemModel::expandedDirectories() const

 {
 {

-    m_urlsToExpand = urls;
+    QSet<QUrl> result;
+    const auto dirs = m_expandedDirs;
+    for (const auto &dir : dirs) {
+        result.insert(dir);
+    }
+    return result;

 }
 
 }
 

-void KFileItemModel::setExpanded(const QSet<KUrl>& urls)
+void KFileItemModel::restoreExpandedDirectories(const QSet<QUrl> &urls)

 {
 {

-    const KDirLister* dirLister = m_dirLister.data();
-    if (!dirLister) {
-        return;
-    }
-
-    const int pos = dirLister->url().url().length();
+    m_urlsToExpand = urls;
+}

 
 

-    // Assure that each sub-path of the URLs that should be
-    // expanded is added to m_urlsToExpand too. KDirLister
+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
     // expanded.
     // does not care whether the parent-URL has already been
     // expanded.

-    QSetIterator<KUrl> it1(urls);
-    while (it1.hasNext()) {
-        const KUrl& url = it1.next();
+    QUrl urlToExpand = m_dirLister->url();
+    const int pos = urlToExpand.path().length();

 
 

-        KUrl urlToExpand = dirLister->url();
-        const QStringList subDirs = url.url().mid(pos).split(QDir::separator());
-        for (int i = 0; i < subDirs.count(); ++i) {
-            urlToExpand.addPath(subDirs.at(i));
-            m_urlsToExpand.insert(urlToExpand);
+    // first subdir can be empty, if m_dirLister->url().path() does not end with '/'
+    // this happens if baseUrl is not root but a home directory, see FoldersPanel,
+    // so using QString::SkipEmptyParts
+    const QStringList subDirs = url.path().mid(pos).split(QDir::separator(), Qt::SkipEmptyParts);
+    for (int i = 0; i < subDirs.count() - 1; ++i) {
+        QString path = urlToExpand.path();
+        if (!path.endsWith(QLatin1Char('/'))) {
+            path.append(QLatin1Char('/'));

         }
         }

+        urlToExpand.setPath(path + subDirs.at(i));
+        m_urlsToExpand.insert(urlToExpand);

     }
 
     // KDirLister::open() must called at least once to trigger an initial
     // loading. The pending URLs that must be restored are handled
     // in slotCompleted().
     }
 
     // KDirLister::open() must called at least once to trigger an initial
     // loading. The pending URLs that must be restored are handled
     // in slotCompleted().

-    QSetIterator<KUrl> it2(m_urlsToExpand);
+    QSetIterator<QUrl> it2(m_urlsToExpand);

     while (it2.hasNext()) {
         const int idx = index(it2.next());
         if (idx >= 0 && !isExpanded(idx)) {
     while (it2.hasNext()) {
         const int idx = index(it2.next());
         if (idx >= 0 && !isExpanded(idx)) {


@@ -498,83 +705,229 @@ void KFileItemModel::setExpanded(const QSet<KUrl>& urls)
     }
 }
 
     }
 }
 

-void KFileItemModel::setNameFilter(const QString& nameFilter)
+void KFileItemModel::setNameFilter(const QString &nameFilter)

 {
     if (m_filter.pattern() != nameFilter) {
         dispatchPendingItemsToInsert();
 {
     if (m_filter.pattern() != nameFilter) {
         dispatchPendingItemsToInsert();

-

         m_filter.setPattern(nameFilter);
         m_filter.setPattern(nameFilter);

+        applyFilters();
+    }
+}

 
 

-        // Check which shown items from m_itemData must get
-        // hidden and hence moved to m_filteredItems.
-        KFileItemList newFilteredItems;
-
-        foreach (ItemData* itemData, m_itemData) {
-            if (!m_filter.matches(itemData->item)) {
-                // Only filter non-expanded items as child items may never
-                // exist without a parent item
-                if (!itemData->values.value("isExpanded").toBool()) {
-                    newFilteredItems.append(itemData->item);
-                    m_filteredItems.insert(itemData->item);
-                }
-            }
+QString KFileItemModel::nameFilter() const
+{
+    return m_filter.pattern();
+}
+
+void KFileItemModel::setMimeTypeFilters(const QStringList &filters)
+{
+    if (m_filter.mimeTypes() != filters) {
+        dispatchPendingItemsToInsert();
+        m_filter.setMimeTypes(filters);
+        applyFilters();
+    }
+}
+
+QStringList KFileItemModel::mimeTypeFilters() const
+{
+    return m_filter.mimeTypes();
+}
+
+void KFileItemModel::applyFilters()
+{
+    // ===STEP 1===
+    // Check which previously shown items from m_itemData must now get
+    // hidden and hence moved from m_itemData into m_filteredItems.
+
+    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

         }
         }

+    }

 
 

-        removeItems(newFilteredItems);
+    // This will remove the newly filtered items from m_itemData
+    removeItems(KItemRangeList::fromSortedContainer(newFilteredIndexes), KeepItemData);

 
 

-        // Check which hidden items from m_filteredItems should
-        // get visible again and hence removed from m_filteredItems.
-        KFileItemList newVisibleItems;
+    // ===STEP 2===
+    // Check which hidden items from m_filteredItems should
+    // become visible again and hence moved from m_filteredItems back into m_itemData.

 
 

-        QMutableSetIterator<KFileItem> it(m_filteredItems);
-        while (it.hasNext()) {
-            const KFileItem item = it.next();
-            if (m_filter.matches(item)) {
-                newVisibleItems.append(item);
-                m_filteredItems.remove(item);
+    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;

         }
         }

+    }

 
 

-        insertItems(newVisibleItems);
+    // ===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);

 }
 
 }
 

-QString KFileItemModel::nameFilter() const
+void KFileItemModel::removeFilteredChildren(const KItemRangeList &itemRanges)

 {
 {

-    return m_filter.pattern();
+    if (m_filteredItems.isEmpty() || !m_requestRole[ExpandedParentsCountRole]) {
+        // There are either no filtered items, or it is not possible to expand
+        // folders -> there cannot be any filtered children.
+        return;
+    }
+
+    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();
+    while (it != m_filteredItems.end()) {
+        if (parents.contains(it.value()->parent)) {
+            delete it.value();
+            it = m_filteredItems.erase(it);
+        } else {
+            ++it;
+        }
+    }
+}
+
+QList<KFileItemModel::RoleInfo> KFileItemModel::rolesInformation()
+{
+    static QList<RoleInfo> rolesInfo;
+    if (rolesInfo.isEmpty()) {
+        int count = 0;
+        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 = 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;
+                rolesInfo.append(info);
+            }
+        }
+    }
+
+    return rolesInfo;

 }
 
 void KFileItemModel::onGroupedSortingChanged(bool current)
 {
 }
 
 void KFileItemModel::onGroupedSortingChanged(bool current)
 {

-    Q_UNUSED(current);
+    Q_UNUSED(current)

     m_groups.clear();
 }
 
     m_groups.clear();
 }
 

-void KFileItemModel::onSortRoleChanged(const QByteArray& current, const QByteArray& previous)
+void KFileItemModel::onSortRoleChanged(const QByteArray &current, const QByteArray &previous, bool resortItems)

 {
 {

-    Q_UNUSED(previous);
-    m_sortRole = roleIndex(current);
+    Q_UNUSED(previous)
+    m_sortRole = typeForRole(current);

 
 

-#ifdef KFILEITEMMODEL_DEBUG

     if (!m_requestRole[m_sortRole]) {
     if (!m_requestRole[m_sortRole]) {

-        kWarning() << "The sort-role has been changed to a role that has not been received yet";
+        QSet<QByteArray> newRoles = m_roles;
+        newRoles << current;
+        setRoles(newRoles);

     }
     }

-#endif

 
 

-    resortAllItems();
+    if (resortItems) {
+        resortAllItems();
+    }

 }
 
 void KFileItemModel::onSortOrderChanged(Qt::SortOrder current, Qt::SortOrder previous)
 {
 }
 
 void KFileItemModel::onSortOrderChanged(Qt::SortOrder current, Qt::SortOrder previous)
 {

-    Q_UNUSED(current);
-    Q_UNUSED(previous);
-    resortAllItems();    
+    Q_UNUSED(current)
+    Q_UNUSED(previous)
+    resortAllItems();
+}
+
+void KFileItemModel::loadSortingSettings()
+{
+    using Choice = GeneralSettings::EnumSortingChoice;
+    switch (GeneralSettings::sortingChoice()) {
+    case Choice::NaturalSorting:
+        m_naturalSorting = true;
+        m_collator.setCaseSensitivity(Qt::CaseInsensitive);
+        break;
+    case Choice::CaseSensitiveSorting:
+        m_naturalSorting = false;
+        m_collator.setCaseSensitivity(Qt::CaseSensitive);
+        break;
+    case Choice::CaseInsensitiveSorting:
+        m_naturalSorting = false;
+        m_collator.setCaseSensitivity(Qt::CaseInsensitive);
+        break;
+    default:
+        Q_UNREACHABLE();
+    }
+    // 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());

 }
 
 void KFileItemModel::resortAllItems()
 {
     m_resortAllItemsTimer->stop();
 }
 
 void KFileItemModel::resortAllItems()
 {
     m_resortAllItemsTimer->stop();

-    
+

     const int itemCount = count();
     if (itemCount <= 0) {
         return;
     const int itemCount = count();
     if (itemCount <= 0) {
         return;


@@ -583,59 +936,74 @@ void KFileItemModel::resortAllItems()
 #ifdef KFILEITEMMODEL_DEBUG
     QElapsedTimer timer;
     timer.start();
 #ifdef KFILEITEMMODEL_DEBUG
     QElapsedTimer timer;
     timer.start();

-    kDebug() << "===========================================================";
-    kDebug() << "Resorting" << itemCount << "items";
+    qCDebug(DolphinDebug) << "===========================================================";
+    qCDebug(DolphinDebug) << "Resorting" << itemCount << "items";

 #endif
 
     // Remember the order of the current URLs so
     // that it can be determined which indexes have
     // been moved because of the resorting.
 #endif
 
     // Remember the order of the current URLs so
     // that it can be determined which indexes have
     // been moved because of the resorting.

-    QList<KUrl> oldUrls;
+    QList<QUrl> oldUrls;

     oldUrls.reserve(itemCount);
     oldUrls.reserve(itemCount);

-    foreach (const ItemData* itemData, m_itemData) {
+    for (const ItemData *itemData : qAsConst(m_itemData)) {

         oldUrls.append(itemData->item.url());
     }
         oldUrls.append(itemData->item.url());
     }

-   
-    m_groups.clear();
+

     m_items.clear();
     m_items.clear();

-    
+    m_items.reserve(itemCount);
+

     // Resort the items
     // Resort the items

-    sort(m_itemData.begin(), m_itemData.end());    
+    sort(m_itemData.begin(), m_itemData.end());

     for (int i = 0; i < itemCount; ++i) {
         m_items.insert(m_itemData.at(i)->item.url(), i);
     }
     for (int i = 0; i < itemCount; ++i) {
         m_items.insert(m_itemData.at(i)->item.url(), i);
     }

-    
-    // Determine the indexes that have been moved
-    bool emitItemsMoved = false;
-    QList<int> movedToIndexes;
-    movedToIndexes.reserve(itemCount);
-    for (int i = 0; i < itemCount; i++) {
-        const int newIndex = m_items.value(oldUrls.at(i).url());
-        movedToIndexes.append(newIndex);
-        if (!emitItemsMoved && newIndex != i) {
-            emitItemsMoved = true;
+
+    // Determine the first index that has been moved.
+    int firstMovedIndex = 0;
+    while (firstMovedIndex < itemCount && firstMovedIndex == m_items.value(oldUrls.at(firstMovedIndex))) {
+        ++firstMovedIndex;
+    }
+
+    const bool itemsHaveMoved = firstMovedIndex < itemCount;
+    if (itemsHaveMoved) {
+        m_groups.clear();
+
+        int lastMovedIndex = itemCount - 1;
+        while (lastMovedIndex > firstMovedIndex && lastMovedIndex == m_items.value(oldUrls.at(lastMovedIndex))) {
+            --lastMovedIndex;
+        }
+
+        Q_ASSERT(firstMovedIndex <= lastMovedIndex);
+
+        // Create a list movedToIndexes, which has the property that
+        // movedToIndexes[i] is the new index of the item with the old index
+        // firstMovedIndex + i.
+        const int movedItemsCount = lastMovedIndex - firstMovedIndex + 1;
+        QList<int> movedToIndexes;
+        movedToIndexes.reserve(movedItemsCount);
+        for (int i = firstMovedIndex; i <= lastMovedIndex; ++i) {
+            const int newIndex = m_items.value(oldUrls.at(i));
+            movedToIndexes.append(newIndex);

         }
         }

-    }   

 
 

-    if (emitItemsMoved) {
-        emit itemsMoved(KItemRange(0, itemCount), movedToIndexes);
+        Q_EMIT itemsMoved(KItemRange(firstMovedIndex, movedItemsCount), movedToIndexes);
+    } else if (groupedSorting()) {
+        // The groups might have changed even if the order of the items has not.
+        const QList<QPair<int, QVariant>> oldGroups = m_groups;
+        m_groups.clear();
+        if (groups() != oldGroups) {
+            Q_EMIT groupsChanged();
+        }

     }
     }

-    
+

 #ifdef KFILEITEMMODEL_DEBUG
 #ifdef KFILEITEMMODEL_DEBUG

-    kDebug() << "[TIME] Resorting of" << itemCount << "items:" << timer.elapsed();
-#endif    
+    qCDebug(DolphinDebug) << "[TIME] Resorting of" << itemCount << "items:" << timer.elapsed();
+#endif

 }
 
 void KFileItemModel::slotCompleted()
 {
 }
 
 void KFileItemModel::slotCompleted()
 {

-    if (m_urlsToExpand.isEmpty() && m_minimumUpdateIntervalTimer->isActive()) {
-        // dispatchPendingItems() will be called when the timer
-        // has been expired.
-        m_pendingEmitLoadingCompleted = true;
-        return;
-    }
-
-    m_pendingEmitLoadingCompleted = false;
+    m_maximumUpdateIntervalTimer->stop();

     dispatchPendingItemsToInsert();
 
     if (!m_urlsToExpand.isEmpty()) {
     dispatchPendingItemsToInsert();
 
     if (!m_urlsToExpand.isEmpty()) {


@@ -643,11 +1011,13 @@ void KFileItemModel::slotCompleted()
         // Note that the parent folder must be expanded before any of its subfolders become visible.
         // Therefore, some URLs in m_restoredExpandedUrls might not be visible yet
         // -> we expand the first visible URL we find in m_restoredExpandedUrls.
         // Note that the parent folder must be expanded before any of its subfolders become visible.
         // Therefore, some URLs in m_restoredExpandedUrls might not be visible yet
         // -> we expand the first visible URL we find in m_restoredExpandedUrls.

-        foreach(const KUrl& url, m_urlsToExpand) {
-            const int index = m_items.value(url, -1);
-            if (index >= 0) {
+        // Iterate over a const copy because items are deleted and inserted within the loop
+        const auto urlsToExpand = m_urlsToExpand;
+        for (const QUrl &url : urlsToExpand) {
+            const int indexForUrl = index(url);
+            if (indexForUrl >= 0) {

                 m_urlsToExpand.remove(url);
                 m_urlsToExpand.remove(url);

-                if (setExpanded(index, true)) {
+                if (setExpanded(indexForUrl, true)) {

                     // The dir lister has been triggered. This slot will be called
                     // again after the directory has been expanded.
                     return;
                     // The dir lister has been triggered. This slot will be called
                     // again after the directory has been expanded.
                     return;


@@ -660,192 +1030,385 @@ void KFileItemModel::slotCompleted()
         m_urlsToExpand.clear();
     }
 
         m_urlsToExpand.clear();
     }
 

-    emit loadingCompleted();
-    m_minimumUpdateIntervalTimer->start();
+    Q_EMIT directoryLoadingCompleted();

 }
 
 void KFileItemModel::slotCanceled()
 {
 }
 
 void KFileItemModel::slotCanceled()
 {

-    m_minimumUpdateIntervalTimer->stop();

     m_maximumUpdateIntervalTimer->stop();
     dispatchPendingItemsToInsert();
     m_maximumUpdateIntervalTimer->stop();
     dispatchPendingItemsToInsert();

+
+    Q_EMIT directoryLoadingCanceled();

 }
 
 }
 

-void KFileItemModel::slotNewItems(const KFileItemList& items)
+void KFileItemModel::slotItemsAdded(const QUrl &directoryUrl, const KFileItemList &items)

 {
     Q_ASSERT(!items.isEmpty());
 
 {
     Q_ASSERT(!items.isEmpty());
 

-    if (m_requestRole[ExpansionLevelRole] && m_rootExpansionLevel >= 0) {
-        // To be able to compare whether the new items may be inserted as children
-        // of a parent item the pending items must be added to the model first.
-        dispatchPendingItemsToInsert();
-
-        KFileItem item = items.first();
+    const QUrl parentUrl = m_expandedDirs.value(directoryUrl, directoryUrl.adjusted(QUrl::StripTrailingSlash));

 
 

+    if (m_requestRole[ExpandedParentsCountRole]) {

         // If the expanding of items is enabled, the call
         // dirLister->openUrl(url, KDirLister::Keep) in KFileItemModel::setExpanded()
         // might result in emitting the same items twice due to the Keep-parameter.
         // This case happens if an item gets expanded, collapsed and expanded again
         // before the items could be loaded for the first expansion.
         // If the expanding of items is enabled, the call
         // dirLister->openUrl(url, KDirLister::Keep) in KFileItemModel::setExpanded()
         // might result in emitting the same items twice due to the Keep-parameter.
         // This case happens if an item gets expanded, collapsed and expanded again
         // before the items could be loaded for the first expansion.

-        const int index = m_items.value(item.url(), -1);
-        if (index >= 0) {
+        if (index(items.first().url()) >= 0) {

             // The items are already part of the model.
             return;
         }
 
             // The items are already part of the model.
             return;
         }
 

+        if (directoryUrl != directory()) {
+            // To be able to compare whether the new items may be inserted as children
+            // of a parent item the pending items must be added to the model first.
+            dispatchPendingItemsToInsert();
+        }
+

         // KDirLister keeps the children of items that got expanded once even if
         // they got collapsed again with KFileItemModel::setExpanded(false). So it must be
         // checked whether the parent for new items is still expanded.
         // KDirLister keeps the children of items that got expanded once even if
         // they got collapsed again with KFileItemModel::setExpanded(false). So it must be
         // checked whether the parent for new items is still expanded.

-        KUrl parentUrl = item.url().upUrl();
-        parentUrl.adjustPath(KUrl::RemoveTrailingSlash);
-        const int parentIndex = m_items.value(parentUrl, -1);
+        const int parentIndex = index(parentUrl);

         if (parentIndex >= 0 && !m_itemData[parentIndex]->values.value("isExpanded").toBool()) {
             // The parent is not expanded.
             return;
         }
     }
 
         if (parentIndex >= 0 && !m_itemData[parentIndex]->values.value("isExpanded").toBool()) {
             // The parent is not expanded.
             return;
         }
     }
 

-    if (m_filter.pattern().isEmpty()) {
-        m_pendingItemsToInsert.append(items);
+    const QList<ItemData *> itemDataList = createItemDataList(parentUrl, items);
+
+    if (!m_filter.hasSetFilters()) {
+        m_pendingItemsToInsert.append(itemDataList);

     } else {
     } else {

-        // The name-filter is active. Hide filtered items
+        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.
         // before inserting them into the model and remember
         // the filtered items in m_filteredItems.

-        KFileItemList filteredItems;
-        foreach (const KFileItem& item, items) {
-            if (m_filter.matches(item)) {
-                filteredItems.append(item);
+        for (ItemData *itemData : itemDataList) {
+            if (m_filter.matches(itemData->item)) {
+                m_pendingItemsToInsert.append(itemData);
+                if (itemData->parent) {
+                    parentsToEnsureVisible.insert(itemData->parent);
+                }

             } else {
             } else {

-                m_filteredItems.insert(item);
+                m_filteredItems.insert(itemData->item, itemData);

             }
         }
 
             }
         }
 

-        m_pendingItemsToInsert.append(filteredItems);
+        // 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 (useMaximumUpdateInterval() && !m_maximumUpdateIntervalTimer->isActive()) {
+    if (!m_maximumUpdateIntervalTimer->isActive()) {

         // Assure that items get dispatched if no completed() or canceled() signal is
         // emitted during the maximum update interval.
         m_maximumUpdateIntervalTimer->start();
     }
         // Assure that items get dispatched if no completed() or canceled() signal is
         // 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();
 
 {
     dispatchPendingItemsToInsert();
 

-    KFileItemList itemsToRemove = items;
-    if (m_requestRole[ExpansionLevelRole] && m_rootExpansionLevel >= 0) {
-        // Assure that removing a parent item also results in removing all children
-        foreach (const KFileItem& item, items) {
-            itemsToRemove.append(childItems(item));
+    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;
+        }
+
+        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);
+            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);

         }
     }
 
         }
     }
 

-    if (!m_filteredItems.isEmpty()) {
-        foreach (const KFileItem& item, itemsToRemove) {
-            m_filteredItems.remove(item);
+    std::sort(indexesToRemove.begin(), indexesToRemove.end());
+
+    if (m_requestRole[ExpandedParentsCountRole] && !m_expandedDirs.isEmpty()) {
+        // Assure that removing a parent item also results in removing all children
+        QVector<int> indexesToRemoveWithChildren;
+        indexesToRemoveWithChildren.reserve(m_itemData.count());
+
+        const int itemCount = m_itemData.count();
+        for (int index : qAsConst(indexesToRemove)) {
+            indexesToRemoveWithChildren.append(index);
+
+            const int parentLevel = expandedParentsCount(index);
+            int childIndex = index + 1;
+            while (childIndex < itemCount && expandedParentsCount(childIndex) > parentLevel) {
+                indexesToRemoveWithChildren.append(childIndex);
+                ++childIndex;
+            }

         }
         }

+
+        indexesToRemove = indexesToRemoveWithChildren;

     }
 
     }
 

-    removeItems(itemsToRemove);
+    KItemRangeList itemRanges = KItemRangeList::fromSortedContainer(indexesToRemove);
+    removeFilteredChildren(itemRanges);
+
+    // 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
 {
     Q_ASSERT(!items.isEmpty());
 #ifdef KFILEITEMMODEL_DEBUG

-    kDebug() << "Refreshing" << items.count() << "items";
+    qCDebug(DolphinDebug) << "Refreshing" << items.count() << "items";

 #endif
 
 #endif
 

-    m_groups.clear();
-

     // Get the indexes of all items that have been refreshed
     QList<int> indexes;
     indexes.reserve(items.count());
 
     // Get the indexes of all items that have been refreshed
     QList<int> indexes;
     indexes.reserve(items.count());
 

-    QListIterator<QPair<KFileItem, KFileItem> > it(items);
+    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);
+

     while (it.hasNext()) {
     while (it.hasNext()) {

-        const QPair<KFileItem, KFileItem>& itemPair = it.next();
-        const KFileItem& oldItem = itemPair.first;
-        const KFileItem& newItem = itemPair.second;
-        const int index = m_items.value(oldItem.url(), -1);
-        if (index >= 0) {
-            m_itemData[index]->item = newItem;
-            m_itemData[index]->values = retrieveData(newItem);
+        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.
+            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 (itemData->values.value(role) != it.value()) {
+                    itemData->values.insert(role, it.value());
+                    changedRoles.insert(role);
+                }
+            }
+

             m_items.remove(oldItem.url());
             m_items.remove(oldItem.url());

-            m_items.insert(newItem.url(), index);
-            indexes.append(index);
+            // 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);
+            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);
+            if (it != m_filteredItems.end()) {
+                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);
+                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 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;
     }
 

-    // Extract the item-ranges out of the changed indexes
-    qSort(indexes);
-
-    KItemRangeList itemRangeList;
-    int previousIndex = indexes.at(0);
-    int rangeIndex = previousIndex;
-    int rangeCount = 1;
-
-    const int maxIndex = indexes.count() - 1;
-    for (int i = 1; i <= maxIndex; ++i) {
-        const int currentIndex = indexes.at(i);
-        if (currentIndex == previousIndex + 1) {
-            ++rangeCount;
-        } else {
-            itemRangeList.append(KItemRange(rangeIndex, rangeCount));
-
-            rangeIndex = currentIndex;
-            rangeCount = 1;
+    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);
+            }

         }
         }

-        previousIndex = currentIndex;
-    }
-
-    if (rangeCount > 0) {
-        itemRangeList.append(KItemRange(rangeIndex, rangeCount));
+    } else {
+        std::sort(indexes.begin(), indexes.end());

     }
 
     }
 

-    emit itemsChanged(itemRangeList, m_roles);
+    // Extract the item-ranges out of the changed indexes
+    const KItemRangeList itemRangeList = KItemRangeList::fromSortedContainer(indexes);
+    emitItemsChangedAndTriggerResorting(itemRangeList, changedRoles);

 
 

-    resortAllItems();
+    Q_EMIT fileItemsChanged(changedFiles);

 }
 
 void KFileItemModel::slotClear()
 {
 #ifdef KFILEITEMMODEL_DEBUG
 }
 
 void KFileItemModel::slotClear()
 {
 #ifdef KFILEITEMMODEL_DEBUG

-    kDebug() << "Clearing all items";
+    qCDebug(DolphinDebug) << "Clearing all items";

 #endif
 
 #endif
 

+    qDeleteAll(m_filteredItems);

     m_filteredItems.clear();
     m_groups.clear();
 
     m_filteredItems.clear();
     m_groups.clear();
 

-    m_minimumUpdateIntervalTimer->stop();

     m_maximumUpdateIntervalTimer->stop();
     m_resortAllItemsTimer->stop();
     m_maximumUpdateIntervalTimer->stop();
     m_resortAllItemsTimer->stop();

-    m_pendingItemsToInsert.clear();

 
 

-    m_rootExpansionLevel = UninitializedRootExpansionLevel;
+    qDeleteAll(m_pendingItemsToInsert);
+    m_pendingItemsToInsert.clear();

 
     const int removedCount = m_itemData.count();
     if (removedCount > 0) {
         qDeleteAll(m_itemData);
         m_itemData.clear();
         m_items.clear();
 
     const int removedCount = m_itemData.count();
     if (removedCount > 0) {
         qDeleteAll(m_itemData);
         m_itemData.clear();
         m_items.clear();

-        emit itemsRemoved(KItemRangeList() << KItemRange(0, removedCount));
+        Q_EMIT itemsRemoved(KItemRangeList() << KItemRange(0, removedCount));

     }
 
     }
 

-    m_expandedUrls.clear();
+    m_expandedDirs.clear();

 }
 
 }
 

-void KFileItemModel::slotClear(const KUrl& url)
+void KFileItemModel::slotSortingChoiceChanged()

 {
 {

-    Q_UNUSED(url);
+    loadSortingSettings();
+    resortAllItems();

 }
 
 void KFileItemModel::dispatchPendingItemsToInsert()
 }
 
 void KFileItemModel::dispatchPendingItemsToInsert()


@@ -854,221 +1417,320 @@ void KFileItemModel::dispatchPendingItemsToInsert()
         insertItems(m_pendingItemsToInsert);
         m_pendingItemsToInsert.clear();
     }
         insertItems(m_pendingItemsToInsert);
         m_pendingItemsToInsert.clear();
     }

-
-    if (m_pendingEmitLoadingCompleted) {
-        emit loadingCompleted();
-    }

 }
 
 }
 

-void KFileItemModel::insertItems(const KFileItemList& items)
+void KFileItemModel::insertItems(QList<ItemData *> &newItems)

 {
 {

-    if (items.isEmpty()) {
+    if (newItems.isEmpty()) {

         return;
     }
 
 #ifdef KFILEITEMMODEL_DEBUG
     QElapsedTimer timer;
     timer.start();
         return;
     }
 
 #ifdef KFILEITEMMODEL_DEBUG
     QElapsedTimer timer;
     timer.start();

-    kDebug() << "===========================================================";
-    kDebug() << "Inserting" << items.count() << "items";
+    qCDebug(DolphinDebug) << "===========================================================";
+    qCDebug(DolphinDebug) << "Inserting" << newItems.count() << "items";

 #endif
 
     m_groups.clear();
 #endif
 
     m_groups.clear();

+    prepareItemsForSorting(newItems);
+
+    // Natural sorting of items can be very slow. However, it becomes much faster
+    // if the input sequence is already mostly sorted. Therefore, we first sort
+    // 'newItems' according to the QStrings using QString::operator<(), which is quite fast.
+    if (m_naturalSorting) {
+        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) {
+                const QByteArray role = roleForType(m_sortRole);
+                return a->values.value(role).toString() < b->values.value(role).toString();
+            };
+            parallelMergeSort(newItems.begin(), newItems.end(), lambdaLessThan, QThread::idealThreadCount());
+        }
+    }

 
 

-    QList<ItemData*> sortedItems = createItemDataList(items);
-    sort(sortedItems.begin(), sortedItems.end());
+    sort(newItems.begin(), newItems.end());

 
 #ifdef KFILEITEMMODEL_DEBUG
 
 #ifdef KFILEITEMMODEL_DEBUG

-    kDebug() << "[TIME] Sorting:" << timer.elapsed();
+    qCDebug(DolphinDebug) << "[TIME] Sorting:" << timer.elapsed();

 #endif
 
     KItemRangeList itemRanges;
 #endif
 
     KItemRangeList itemRanges;

-    int targetIndex = 0;
-    int sourceIndex = 0;
-    int insertedAtIndex = -1;        // Index for the current item-range
-    int insertedCount = 0;           // Count for the current item-range
-    int previouslyInsertedCount = 0; // Sum of previously inserted items for all ranges
-    while (sourceIndex < sortedItems.count()) {
-        // Find target index from m_items to insert the current item
-        // in a sorted order
-        const int previousTargetIndex = targetIndex;
-        while (targetIndex < m_itemData.count()) {
-            if (!lessThan(m_itemData.at(targetIndex), sortedItems.at(sourceIndex))) {
-                break;
+    const int existingItemCount = m_itemData.count();
+    const int newItemCount = newItems.count();
+    const int totalItemCount = existingItemCount + newItemCount;
+
+    if (existingItemCount == 0) {
+        // Optimization for the common special case that there are no
+        // items in the model yet. Happens, e.g., when entering a folder.
+        m_itemData = newItems;
+        itemRanges << KItemRange(0, newItemCount);
+    } else {
+        m_itemData.reserve(totalItemCount);
+        for (int i = existingItemCount; i < totalItemCount; ++i) {
+            m_itemData.append(nullptr);
+        }
+
+        // We build the new list m_itemData in reverse order to minimize
+        // the number of moves and guarantee O(N) complexity.
+        int targetIndex = totalItemCount - 1;
+        int sourceIndexExistingItems = existingItemCount - 1;
+        int sourceIndexNewItems = newItemCount - 1;
+
+        int rangeCount = 0;
+
+        while (sourceIndexNewItems >= 0) {
+            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.
+                if (rangeCount > 0) {
+                    itemRanges << KItemRange(sourceIndexExistingItems + 1, rangeCount);
+                    rangeCount = 0;
+                }
+
+                m_itemData[targetIndex] = m_itemData.at(sourceIndexExistingItems);
+                --sourceIndexExistingItems;
+            } else {
+                // Insert a new item into the list.
+                ++rangeCount;
+                m_itemData[targetIndex] = newItem;
+                --sourceIndexNewItems;

             }
             }

-            ++targetIndex;
+            --targetIndex;

         }
 
         }
 

-        if (targetIndex - previousTargetIndex > 0 && insertedAtIndex >= 0) {
-            itemRanges << KItemRange(insertedAtIndex, insertedCount);
-            previouslyInsertedCount += insertedCount;
-            insertedAtIndex = targetIndex - previouslyInsertedCount;
-            insertedCount = 0;
+        // Push the final item range to itemRanges.
+        if (rangeCount > 0) {
+            itemRanges << KItemRange(sourceIndexExistingItems + 1, rangeCount);

         }
 
         }
 

-        // Insert item at the position targetIndex by transfering
-        // the ownership of the item-data from sortedItems to m_itemData.
-        // m_items will be inserted after the loop (see comment below)
-        m_itemData.insert(targetIndex, sortedItems.at(sourceIndex));        
-        ++insertedCount;
-
-        if (insertedAtIndex < 0) {
-            insertedAtIndex = targetIndex;
-            Q_ASSERT(previouslyInsertedCount == 0);
-        }
-        ++targetIndex;
-        ++sourceIndex;
+        // Note that itemRanges is still sorted in reverse order.
+        std::reverse(itemRanges.begin(), itemRanges.end());

     }
 
     }
 

-    // The indexes of all m_items must be adjusted, not only the index
-    // of the new items
-    const int itemDataCount = m_itemData.count();
-    for (int i = 0; i < itemDataCount; ++i) {
-        m_items.insert(m_itemData.at(i)->item.url(), i);
-    }
+    // The indexes in m_items are not correct anymore. Therefore, we clear m_items.
+    // It will be re-populated with the updated indices if index(const QUrl&) is called.
+    m_items.clear();

 
 

-    itemRanges << KItemRange(insertedAtIndex, insertedCount);
-    emit itemsInserted(itemRanges);
+    Q_EMIT itemsInserted(itemRanges);

 
 #ifdef KFILEITEMMODEL_DEBUG
 
 #ifdef KFILEITEMMODEL_DEBUG

-    kDebug() << "[TIME] Inserting of" << items.count() << "items:" << timer.elapsed();
+    qCDebug(DolphinDebug) << "[TIME] Inserting of" << newItems.count() << "items:" << timer.elapsed();

 #endif
 }
 
 #endif
 }
 

-void KFileItemModel::removeItems(const KFileItemList& items)
+void KFileItemModel::removeItems(const KItemRangeList &itemRanges, RemoveItemsBehavior behavior)

 {
 {

-    if (items.isEmpty()) {
+    if (itemRanges.isEmpty()) {

         return;
     }
 
         return;
     }
 

-#ifdef KFILEITEMMODEL_DEBUG
-    kDebug() << "Removing " << items.count() << "items";
-#endif
-

     m_groups.clear();
 
     m_groups.clear();
 

-    QList<ItemData*> sortedItems;
-    sortedItems.reserve(items.count());
-    foreach (const KFileItem& item, items) {
-        const int index = m_items.value(item.url(), -1);
-        if (index >= 0) {
-            sortedItems.append(m_itemData.at(index));
-        }
-    }
-    sort(sortedItems.begin(), sortedItems.end());
+    // Step 1: Remove the items from m_itemData, and free the ItemData.
+    int removedItemsCount = 0;
+    for (const KItemRange &range : itemRanges) {
+        removedItemsCount += range.count;

 
 

-    QList<int> indexesToRemove;
-    indexesToRemove.reserve(items.count());
-
-    // Calculate the item ranges that will get deleted
-    KItemRangeList itemRanges;
-    int removedAtIndex = -1;
-    int removedCount = 0;
-    int targetIndex = 0;
-    foreach (const ItemData* itemData, sortedItems) {
-        const KFileItem& itemToRemove = itemData->item;
-        
-        const int previousTargetIndex = targetIndex;
-        while (targetIndex < m_itemData.count()) {
-            if (m_itemData.at(targetIndex)->item.url() == itemToRemove.url()) {
-                break;
+        for (int index = range.index; index < range.index + range.count; ++index) {
+            if (behavior == DeleteItemData || (behavior == DeleteItemDataIfUnfiltered && !m_filteredItems.contains(m_itemData.at(index)->item))) {
+                delete m_itemData.at(index);

             }
             }

-            ++targetIndex;
-        }
-        if (targetIndex >= m_itemData.count()) {
-            kWarning() << "Item that should be deleted has not been found!";
-            return;
-        }

 
 

-        if (targetIndex - previousTargetIndex > 0 && removedAtIndex >= 0) {
-            itemRanges << KItemRange(removedAtIndex, removedCount);
-            removedAtIndex = targetIndex;
-            removedCount = 0;
+            m_itemData[index] = nullptr;

         }
         }

+    }
+
+    // Step 2: Remove the ItemData pointers from the list m_itemData.
+    int target = itemRanges.at(0).index;
+    int source = itemRanges.at(0).index + itemRanges.at(0).count;
+    int nextRange = 1;
+
+    const int oldItemDataCount = m_itemData.count();
+    while (source < oldItemDataCount) {
+        m_itemData[target] = m_itemData[source];
+        ++target;
+        ++source;

 
 

-        indexesToRemove.append(targetIndex);
-        if (removedAtIndex < 0) {
-            removedAtIndex = targetIndex;
+        if (nextRange < itemRanges.count() && source == itemRanges.at(nextRange).index) {
+            // Skip the items in the next removed range.
+            source += itemRanges.at(nextRange).count;
+            ++nextRange;

         }
         }

-        ++removedCount;
-        ++targetIndex;

     }
 
     }
 

-    // Delete the items
-    for (int i = indexesToRemove.count() - 1; i >= 0; --i) {
-        const int indexToRemove = indexesToRemove.at(i);
-        ItemData* data = m_itemData.at(indexToRemove);
+    m_itemData.erase(m_itemData.end() - removedItemsCount, m_itemData.end());

 
 

-        m_items.remove(data->item.url());
+    // The indexes in m_items are not correct anymore. Therefore, we clear m_items.
+    // It will be re-populated with the updated indices if index(const QUrl&) is called.
+    m_items.clear();

 
 

-        delete data;
-        m_itemData.removeAt(indexToRemove);
-    }
+    Q_EMIT itemsRemoved(itemRanges);
+}

 
 

-    // The indexes of all m_items must be adjusted, not only the index
-    // of the removed items
-    const int itemDataCount = m_itemData.count();
-    for (int i = 0; i < itemDataCount; ++i) {
-        m_items.insert(m_itemData.at(i)->item.url(), i);
+QList<KFileItemModel::ItemData *> KFileItemModel::createItemDataList(const QUrl &parentUrl, const KFileItemList &items) const
+{
+    if (m_sortRole == 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);

     }
 
     }
 

-    if (count() <= 0) {
-        m_rootExpansionLevel = UninitializedRootExpansionLevel;
+    // We search for the parent in m_itemData and then in m_filteredItems if necessary
+    const int parentIndex = index(parentUrl);
+    ItemData *parentItem = parentIndex < 0 ? m_filteredItems.value(KFileItem(parentUrl), nullptr) : m_itemData.at(parentIndex);
+
+    QList<ItemData *> itemDataList;
+    itemDataList.reserve(items.count());
+
+    for (const KFileItem &item : items) {
+        ItemData *itemData = new ItemData();
+        itemData->item = item;
+        itemData->parent = parentItem;
+        itemDataList.append(itemData);

     }
 
     }
 

-    itemRanges << KItemRange(removedAtIndex, removedCount);
-    emit itemsRemoved(itemRanges);
+    return itemDataList;

 }
 
 }
 

-QList<KFileItemModel::ItemData*> KFileItemModel::createItemDataList(const KFileItemList& items) const
+void KFileItemModel::prepareItemsForSorting(QList<ItemData *> &itemDataList)

 {
 {

-    QList<ItemData*> itemDataList;
-    itemDataList.reserve(items.count());
+    switch (m_sortRole) {
+    case ExtensionRole:
+    case PermissionsRole:
+    case OwnerRole:
+    case GroupRole:
+    case DestinationRole:
+    case PathRole:
+    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)) {
+            if (itemData->values.isEmpty()) {
+                itemData->values = retrieveData(itemData->item, itemData->parent);
+            }
+        }
+        break;

 
 

-    foreach (const KFileItem& item, items) {
-        ItemData* itemData = new ItemData();
-        itemData->item = item;
-        itemData->values = retrieveData(item);
-        itemData->parent = 0;
-
-        const bool determineParent = m_requestRole[ExpansionLevelRole]
-                                     && itemData->values["expansionLevel"].toInt() > 0;
-        if (determineParent) {
-            KUrl parentUrl = item.url().upUrl();
-            parentUrl.adjustPath(KUrl::RemoveTrailingSlash);
-            const int parentIndex = m_items.value(parentUrl, -1);
-            if (parentIndex >= 0) {
-                itemData->parent = m_itemData.at(parentIndex);
-            } else {
-                kWarning() << "Parent item not found for" << item.url();
+    case TypeRole:
+        // At least store the data including the file type for items with known MIME type.
+        for (ItemData *itemData : qAsConst(itemDataList)) {
+            if (itemData->values.isEmpty()) {
+                const KFileItem item = itemData->item;
+                if (item.isDir() || item.isMimeTypeKnown()) {
+                    itemData->values = retrieveData(itemData->item, itemData->parent);
+                }

             }
         }
             }
         }

+        break;

 
 

-        itemDataList.append(itemData);
+    default:
+        // The other roles are either resolved by KFileItemModelRolesUpdater
+        // (this includes the SizeRole for directories), or they do not need
+        // to be stored in the QHash "values" for sorting because the data can
+        // be retrieved directly from the KFileItem (NameRole, SizeRole for files,
+        // DateRole).
+        break;
+    }
+}
+
+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;
+    if (parent) {
+        if (parent->parent) {
+            Q_ASSERT(parent->values.contains("expandedParentsCount"));
+            return parent->values.value("expandedParentsCount").toInt() + 1;
+        } else {
+            return 1;
+        }
+    } else {
+        return 0;

     }
     }

- 
-    return itemDataList;

 }
 
 void KFileItemModel::removeExpandedItems()
 {
 }
 
 void KFileItemModel::removeExpandedItems()
 {

-    KFileItemList expandedItems;
+    QVector<int> indexesToRemove;

 
     const int maxIndex = m_itemData.count() - 1;
     for (int i = 0; i <= maxIndex; ++i) {
 
     const int maxIndex = m_itemData.count() - 1;
     for (int i = 0; i <= maxIndex; ++i) {

-        const ItemData* itemData = m_itemData.at(i);
-        if (itemData->values.value("expansionLevel").toInt() > 0) {
-            expandedItems.append(itemData->item);
+        const ItemData *itemData = m_itemData.at(i);
+        if (itemData->parent) {
+            indexesToRemove.append(i);

         }
     }
 
         }
     }
 

-    // The m_rootExpansionLevel may not get reset before all items with
-    // a bigger expansionLevel have been removed.
-    Q_ASSERT(m_rootExpansionLevel >= 0);
-    removeItems(expandedItems);
+    removeItems(KItemRangeList::fromSortedContainer(indexesToRemove), DeleteItemData);
+    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();

 
 

-    m_rootExpansionLevel = UninitializedRootExpansionLevel;
-    m_expandedUrls.clear();
+    while (it != end) {
+        if (it.value()->parent) {
+            delete it.value();
+            it = m_filteredItems.erase(it);
+        } else {
+            ++it;
+        }
+    }
+}
+
+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) {
+            bool needsResorting = false;
+
+            const int first = range.index;
+            const int last = range.index + range.count - 1;
+
+            // Resorting the model is necessary if
+            // (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)) {
+                needsResorting = true;
+            } 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) {
+                    if (lessThan(m_itemData.at(index + 1), m_itemData.at(index), m_collator)) {
+                        needsResorting = true;
+                        break;
+                    }
+                }
+            }
+
+            if (needsResorting) {
+                m_resortAllItemsTimer->start();
+                return;
+            }
+        }
+    }
+
+    if (groupedSorting() && changedRoles.contains(sortRole())) {
+        // The position is still correct, but the groups might have changed
+        // if the changed item is either the first or the last item in a
+        // group.
+        // In principle, we could try to find out if the item really is the
+        // first or last one in its group and then update the groups
+        // (possibly with a delayed timer to make sure that we don't
+        // re-calculate the groups very often if items are updated one by
+        // one), but starting m_resortAllItemsTimer is easier.
+        m_resortAllItemsTimer->start();
+    }

 }
 
 void KFileItemModel::resetRoles()
 }
 
 void KFileItemModel::resetRoles()


@@ -1078,158 +1740,246 @@ void KFileItemModel::resetRoles()
     }
 }
 
     }
 }
 

-KFileItemModel::Role KFileItemModel::roleIndex(const QByteArray& role) const
+KFileItemModel::RoleType KFileItemModel::typeForRole(const QByteArray &role) const

 {
 {

-    static QHash<QByteArray, Role> rolesHash;
-    if (rolesHash.isEmpty()) {
-        rolesHash.insert("name", NameRole);
-        rolesHash.insert("size", SizeRole);
-        rolesHash.insert("date", DateRole);
-        rolesHash.insert("permissions", PermissionsRole);
-        rolesHash.insert("owner", OwnerRole);
-        rolesHash.insert("group", GroupRole);
-        rolesHash.insert("type", TypeRole);
-        rolesHash.insert("destination", DestinationRole);
-        rolesHash.insert("path", PathRole);
-        rolesHash.insert("comment", CommentRole);
-        rolesHash.insert("tags", TagsRole);
-        rolesHash.insert("rating", RatingRole);
-        rolesHash.insert("isDir", IsDirRole);
-        rolesHash.insert("isExpanded", IsExpandedRole);
-        rolesHash.insert("isExpandable", IsExpandableRole);
-        rolesHash.insert("expansionLevel", ExpansionLevelRole);
+    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);
+        for (int i = 0; i < count; ++i) {
+            roles.insert(map[i].role, map[i].roleType);
+        }
+
+        // Insert internal roles (take care to synchronize the implementation
+        // with KFileItemModel::roleForType() in case if a change is done).
+        roles.insert("isDir", IsDirRole);
+        roles.insert("isLink", IsLinkRole);
+        roles.insert("isHidden", IsHiddenRole);
+        roles.insert("isExpanded", IsExpandedRole);
+        roles.insert("isExpandable", IsExpandableRole);
+        roles.insert("expandedParentsCount", ExpandedParentsCountRole);
+
+        Q_ASSERT(roles.count() == RolesCount);

     }
     }

-    return rolesHash.value(role, NoRole);
+
+    return roles.value(role, NoRole);
+}
+
+QByteArray KFileItemModel::roleForType(RoleType roleType) const
+{
+    static QHash<RoleType, QByteArray> roles;
+    if (roles.isEmpty()) {
+        // Insert user visible roles that can be accessed with
+        // KFileItemModel::roleInformation()
+        int count = 0;
+        const RoleInfoMap *map = rolesInfoMap(count);
+        for (int i = 0; i < count; ++i) {
+            roles.insert(map[i].roleType, map[i].role);
+        }
+
+        // Insert internal roles (take care to synchronize the implementation
+        // with KFileItemModel::typeForRole() in case if a change is done).
+        roles.insert(IsDirRole, "isDir");
+        roles.insert(IsLinkRole, "isLink");
+        roles.insert(IsHiddenRole, "isHidden");
+        roles.insert(IsExpandedRole, "isExpanded");
+        roles.insert(IsExpandableRole, "isExpandable");
+        roles.insert(ExpandedParentsCountRole, "expandedParentsCount");
+
+        Q_ASSERT(roles.count() == RolesCount);
+    };
+
+    return roles.value(roleType);

 }
 
 }
 

-QHash<QByteArray, QVariant> KFileItemModel::retrieveData(const KFileItem& item) 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
     // and hence will be retrieved asynchronously by KFileItemModelRolesUpdater.
     QHash<QByteArray, QVariant> data;
     // 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
     // and hence will be retrieved asynchronously by KFileItemModelRolesUpdater.
     QHash<QByteArray, QVariant> data;

-    data.insert("iconPixmap", QPixmap());
-    data.insert("url", item.url());
+    data.insert(sharedValue("url"), item.url());

 
     const bool isDir = item.isDir();
 
     const bool isDir = item.isDir();

-    if (m_requestRole[IsDirRole]) {
-        data.insert("isDir", isDir);
+    if (m_requestRole[IsDirRole] && isDir) {
+        data.insert(sharedValue("isDir"), true);
+    }
+
+    if (m_requestRole[IsLinkRole] && item.isLink()) {
+        data.insert(sharedValue("isLink"), true);
+    }
+
+    if (m_requestRole[IsHiddenRole]) {
+        data.insert(sharedValue("isHidden"), item.isHidden());

     }
 
     if (m_requestRole[NameRole]) {
     }
 
     if (m_requestRole[NameRole]) {

-        data.insert("name", item.text());
+        data.insert(sharedValue("text"), item.text());

     }
 
     }
 

-    if (m_requestRole[SizeRole]) {
-        if (isDir) {
-            data.insert("size", QVariant());
-        } else {
-            data.insert("size", item.size());
-        }
+    if (m_requestRole[ExtensionRole] && !isDir) {
+        data.insert(sharedValue("extension"), QFileInfo(item.name()).suffix());

     }
 
     }
 

-    if (m_requestRole[DateRole]) {
-        // Don't use KFileItem::timeString() as this is too expensive when
-        // having several thousands of items. Instead the formatting of the
-        // date-time will be done on-demand by the view when the date will be shown.
-        const KDateTime dateTime = item.time(KFileItem::ModificationTime);
-        data.insert("date", dateTime.dateTime());
+    if (m_requestRole[SizeRole] && !isDir) {
+        data.insert(sharedValue("size"), item.size());
+    }
+
+    if (m_requestRole[ModificationTimeRole]) {
+        // Don't use KFileItem::timeString() or KFileItem::time() as this is too expensive when
+        // having several thousands of items. Instead read the raw number from UDSEntry directly
+        // and the formatting of the date-time will be done on-demand by the view when the date will be shown.
+        const long long dateTime = item.entry().numberValue(KIO::UDSEntry::UDS_MODIFICATION_TIME, -1);
+        data.insert(sharedValue("modificationtime"), dateTime);
+    }
+
+    if (m_requestRole[CreationTimeRole]) {
+        // Don't use KFileItem::timeString() or KFileItem::time() as this is too expensive when
+        // having several thousands of items. Instead read the raw number from UDSEntry directly
+        // and the formatting of the date-time will be done on-demand by the view when the date will be shown.
+        const long long dateTime = item.entry().numberValue(KIO::UDSEntry::UDS_CREATION_TIME, -1);
+        data.insert(sharedValue("creationtime"), dateTime);
+    }
+
+    if (m_requestRole[AccessTimeRole]) {
+        // Don't use KFileItem::timeString() or KFileItem::time() as this is too expensive when
+        // having several thousands of items. Instead read the raw number from UDSEntry directly
+        // and the formatting of the date-time will be done on-demand by the view when the date will be shown.
+        const long long dateTime = item.entry().numberValue(KIO::UDSEntry::UDS_ACCESS_TIME, -1);
+        data.insert(sharedValue("accesstime"), dateTime);

     }
 
     if (m_requestRole[PermissionsRole]) {
     }
 
     if (m_requestRole[PermissionsRole]) {

-        data.insert("permissions", item.permissionsString());
+        data.insert(sharedValue("permissions"), item.permissionsString());

     }
 
     if (m_requestRole[OwnerRole]) {
     }
 
     if (m_requestRole[OwnerRole]) {

-        data.insert("owner", item.user());
+        data.insert(sharedValue("owner"), item.user());

     }
 
     if (m_requestRole[GroupRole]) {
     }
 
     if (m_requestRole[GroupRole]) {

-        data.insert("group", item.group());
+        data.insert(sharedValue("group"), item.group());

     }
 
     if (m_requestRole[DestinationRole]) {
         QString destination = item.linkDest();
         if (destination.isEmpty()) {
     }
 
     if (m_requestRole[DestinationRole]) {
         QString destination = item.linkDest();
         if (destination.isEmpty()) {

-            destination = i18nc("@item:intable", "No destination");
+            destination = QLatin1Char('-');

         }
         }

-        data.insert("destination", destination);
+        data.insert(sharedValue("destination"), destination);

     }
 
     if (m_requestRole[PathRole]) {
         QString path;
     }
 
     if (m_requestRole[PathRole]) {
         QString path;

-        if (item.url().protocol() == QLatin1String("trash")) {
+        if (item.url().scheme() == QLatin1String("trash")) {

             path = item.entry().stringValue(KIO::UDSEntry::UDS_EXTRA);
         } else {
             path = item.entry().stringValue(KIO::UDSEntry::UDS_EXTRA);
         } else {

+            // For performance reasons cache the home-path in a static QString
+            // (see QDir::homePath() for more details)
+            static QString homePath;
+            if (homePath.isEmpty()) {
+                homePath = QDir::homePath();
+            }
+

             path = item.localPath();
             path = item.localPath();

+            if (path.startsWith(homePath)) {
+                path.replace(0, homePath.length(), QLatin1Char('~'));
+            }

         }
 
         const int index = path.lastIndexOf(item.text());
         path = path.mid(0, index - 1);
         }
 
         const int index = path.lastIndexOf(item.text());
         path = path.mid(0, index - 1);

-        data.insert("path", path);
+        data.insert(sharedValue("path"), path);

     }
 
     }
 

-    if (m_requestRole[IsExpandedRole]) {
-        data.insert("isExpanded", false);
+    if (m_requestRole[DeletionTimeRole]) {
+        QDateTime deletionTime;
+        if (item.url().scheme() == QLatin1String("trash")) {
+            deletionTime = QDateTime::fromString(item.entry().stringValue(KIO::UDSEntry::UDS_EXTRA + 1), Qt::ISODate);
+        }
+        data.insert(sharedValue("deletiontime"), deletionTime);

     }
 
     }
 

-    if (m_requestRole[IsExpandableRole]) {
-        data.insert("isExpandable", item.isDir() && item.url() == item.targetUrl());
+    if (m_requestRole[IsExpandableRole] && isDir) {
+        data.insert(sharedValue("isExpandable"), true);

     }
 
     }
 

-    if (m_requestRole[ExpansionLevelRole]) {
-        if (m_rootExpansionLevel == UninitializedRootExpansionLevel && m_dirLister.data()) {
-            const KUrl rootUrl = m_dirLister.data()->url();
-            const QString protocol = rootUrl.protocol();
-            const bool forceRootExpansionLevel = (protocol == QLatin1String("trash") ||
-                                                  protocol == QLatin1String("nepomuk") ||
-                                                  protocol == QLatin1String("remote") ||
-                                                  protocol.contains(QLatin1String("search")));
-            if (forceRootExpansionLevel) {
-                m_rootExpansionLevel = ForceRootExpansionLevel;
-            } else {
-                const QString rootDir = rootUrl.directory(KUrl::AppendTrailingSlash);
-                m_rootExpansionLevel = rootDir.count('/');
-                if (m_rootExpansionLevel == 1) {
-                    // Special case: The root is already reached and no parent is available
-                    --m_rootExpansionLevel;
-                }
-            }
-        }
-
-        if (m_rootExpansionLevel == ForceRootExpansionLevel) {
-            data.insert("expansionLevel", -1);
-        } else {
-            const QString dir = item.url().directory(KUrl::AppendTrailingSlash);
-            const int level = dir.count('/') - m_rootExpansionLevel - 1;
-            data.insert("expansionLevel", level);
+    if (m_requestRole[ExpandedParentsCountRole]) {
+        if (parent) {
+            const int level = expandedParentsCount(parent) + 1;
+            data.insert(sharedValue("expandedParentsCount"), level);

         }
     }
 
     if (item.isMimeTypeKnown()) {
         }
     }
 
     if (item.isMimeTypeKnown()) {

-        data.insert("iconName", item.iconName());
+        QString iconName = item.iconName();
+        if (!QIcon::hasThemeIcon(iconName)) {
+            QMimeType mimeType = QMimeDatabase().mimeTypeForName(item.mimetype());
+            iconName = mimeType.genericIconName();
+        }
+
+        data.insert(sharedValue("iconName"), iconName);

 
         if (m_requestRole[TypeRole]) {
 
         if (m_requestRole[TypeRole]) {

-            data.insert("type", item.mimeComment());
+            data.insert(sharedValue("type"), item.mimeComment());

         }
         }

+    } else if (m_requestRole[TypeRole] && isDir) {
+        static const QString folderMimeType = item.mimeComment();
+        data.insert(sharedValue("type"), folderMimeType);

     }
 
     return data;
 }
 
     }
 
     return data;
 }
 

-bool KFileItemModel::lessThan(const ItemData* a, const ItemData* b) const
+bool KFileItemModel::lessThan(const ItemData *a, const ItemData *b, const QCollator &collator) const

 {
     int result = 0;
 
 {
     int result = 0;
 

-    if (m_rootExpansionLevel >= 0) {
-        result = expansionLevelsCompare(a, b);
-        if (result != 0) {
-            // The items have parents with different expansion levels
-            return (sortOrder() == Qt::AscendingOrder) ? result < 0 : result > 0;
+    if (a->parent != b->parent) {
+        const int expansionLevelA = expandedParentsCount(a);
+        const int expansionLevelB = expandedParentsCount(b);
+
+        // If b has a higher expansion level than a, check if a is a parent
+        // of b, and make sure that both expansion levels are equal otherwise.
+        for (int i = expansionLevelB; i > expansionLevelA; --i) {
+            if (b->parent == a) {
+                return true;
+            }
+            b = b->parent;
+        }
+
+        // If a has a higher expansion level than a, check if b is a parent
+        // of a, and make sure that both expansion levels are equal otherwise.
+        for (int i = expansionLevelA; i > expansionLevelB; --i) {
+            if (a->parent == b) {
+                return false;
+            }
+            a = a->parent;
+        }
+
+        Q_ASSERT(expandedParentsCount(a) == expandedParentsCount(b));
+
+        // Compare the last parents of a and b which are different.
+        while (a->parent != b->parent) {
+            a = a->parent;
+            b = b->parent;
+        }
+    }
+
+    // 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_sortFoldersFirst || m_sortRole == SizeRole) {
+    if (m_sortDirsFirst || (DetailsModeSettings::directorySizeCount() && m_sortRole == SizeRole)) {

         const bool isDirA = a->item.isDir();
         const bool isDirB = b->item.isDir();
         if (isDirA && !isDirB) {
         const bool isDirA = a->item.isDir();
         const bool isDirB = b->item.isDir();
         if (isDirA && !isDirB) {


@@ -1239,15 +1989,39 @@ bool KFileItemModel::lessThan(const ItemData* a, const ItemData* b) const
         }
     }
 
         }
     }
 

-    result = sortRoleCompare(a, b);
+    result = sortRoleCompare(a, b, collator);

 
     return (sortOrder() == Qt::AscendingOrder) ? result < 0 : result > 0;
 }
 
 
     return (sortOrder() == Qt::AscendingOrder) ? result < 0 : result > 0;
 }
 

-int KFileItemModel::sortRoleCompare(const ItemData* a, const ItemData* b) const
+void KFileItemModel::sort(const QList<KFileItemModel::ItemData *>::iterator &begin, const QList<KFileItemModel::ItemData *>::iterator &end) const

 {
 {

-    const KFileItem& itemA = a->item;
-    const KFileItem& itemB = b->item;
+    auto lambdaLessThan = [&](const KFileItemModel::ItemData *a, const KFileItemModel::ItemData *b) {
+        return lessThan(a, b, m_collator);
+    };
+
+    if (m_sortRole == NameRole || isRoleValueNatural(m_sortRole)) {
+        // Sorting by string can be expensive, in particular if natural sorting is
+        // enabled. Use all CPU cores to speed up the sorting process.
+        static const int numberOfThreads = QThread::idealThreadCount();
+        parallelMergeSort(begin, end, lambdaLessThan, numberOfThreads);
+    } else {
+        // Sorting by other roles is quite fast. Use only one thread to prevent
+        // problems caused by non-reentrant comparison functions, see
+        // https://bugs.kde.org/show_bug.cgi?id=312679
+        mergeSort(begin, end, lambdaLessThan);
+    }
+}
+
+int KFileItemModel::sortRoleCompare(const ItemData *a, const ItemData *b, const QCollator &collator) const
+{
+    // 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;
 
 
     int result = 0;
 


@@ -1256,64 +2030,134 @@ int KFileItemModel::sortRoleCompare(const ItemData* a, const ItemData* b) const
         // The name role is handled as default fallback after the switch
         break;
 
         // The name role is handled as default fallback after the switch
         break;
 

-    case DateRole: {
-        const KDateTime dateTimeA = itemA.time(KFileItem::ModificationTime);
-        const KDateTime dateTimeB = itemB.time(KFileItem::ModificationTime);
-        if (dateTimeA < dateTimeB) {
-            result = -1;
-        } else if (dateTimeA > dateTimeB) {
-            result = +1;
-        }
-        break;
-    }
-

     case SizeRole: {
     case SizeRole: {

-        if (itemA.isDir()) {
-            Q_ASSERT(itemB.isDir()); // see "if (m_sortFoldersFirst || m_sortRole == SizeRole)" above
-
-            const QVariant valueA = a->values.value("size");
-            const QVariant valueB = b->values.value("size");
-
+        if (DetailsModeSettings::directorySizeCount() && 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 (valueA.isNull()) {

-                result = -1;
+                if (!valueB.isNull()) {
+                    return -1;
+                }

             } else if (valueB.isNull()) {
             } else if (valueB.isNull()) {

-                result = +1;
+                return +1;

             } else {
             } else {

-                result = valueA.value<KIO::filesize_t>() - valueB.value<KIO::filesize_t>();
+                if (valueA.toLongLong() < valueB.toLongLong()) {
+                    return -1;
+                } else if (valueA.toLongLong() > valueB.toLongLong()) {
+                    return +1;
+                }

             }
             }

+            break;
+        }
+
+        KIO::filesize_t sizeA = 0;
+        if (itemA.isDir()) {
+            sizeA = a->values.value("size").toULongLong();
+        } else {
+            sizeA = itemA.size();
+        }
+        KIO::filesize_t sizeB = 0;
+        if (itemB.isDir()) {
+            sizeB = b->values.value("size").toULongLong();

         } else {
         } else {

-            Q_ASSERT(!itemB.isDir()); // see "if (m_sortFoldersFirst || m_sortRole == SizeRole)" above
-            result = itemA.size() - itemB.size();
+            sizeB = itemB.size();
+        }
+        if (sizeA < sizeB) {
+            return -1;
+        } else if (sizeA > sizeB) {
+            return +1;

         }
         break;
     }
 
         }
         break;
     }
 

-    case TypeRole: {
-        result = QString::compare(a->values.value("type").toString(),
-                                  b->values.value("type").toString());
+    case ModificationTimeRole: {
+        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) {
+            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) {
+            return +1;
+        }

         break;
     }
 
         break;
     }
 

-    case CommentRole: {
-        result = QString::compare(a->values.value("comment").toString(),
-                                  b->values.value("comment").toString());
+    case CreationTimeRole: {
+        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) {
+            return -1;
+        } else if (dateTimeA > dateTimeB) {
+            return +1;
+        }

         break;
     }
 
         break;
     }
 

-    case TagsRole: {
-        result = QString::compare(a->values.value("tags").toString(),
-                                  b->values.value("tags").toString());
+    case DeletionTimeRole: {
+        const QDateTime dateTimeA = a->values.value("deletiontime").toDateTime();
+        const QDateTime dateTimeB = b->values.value("deletiontime").toDateTime();
+        if (dateTimeA < dateTimeB) {
+            return -1;
+        } else if (dateTimeA > dateTimeB) {
+            return +1;
+        }

         break;
     }
 
         break;
     }
 

-    case RatingRole: {
-        result = a->values.value("rating").toInt() - b->values.value("rating").toInt();
+    case RatingRole:
+    case WidthRole:
+    case HeightRole:
+    case PublisherRole:
+    case PageCountRole:
+    case WordCountRole:
+    case LineCountRole:
+    case TrackRole:
+    case ReleaseYearRole: {
+        result = a->values.value(roleForType(m_sortRole)).toInt() - b->values.value(roleForType(m_sortRole)).toInt();

         break;
     }
 
         break;
     }
 

-    default:
+    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()) {
+            return -1;
+        } else if (roleValueA.isEmpty() && !roleValueB.isEmpty()) {
+            return +1;
+        } else if (isRoleValueNatural(m_sortRole)) {
+            result = stringCompare(roleValueA, roleValueB, collator);
+        } else {
+            result = QString::compare(roleValueA, roleValueB);
+        }

         break;
     }
         break;
     }

+    }

 
     if (result != 0) {
         // The current sort role was sufficient to define an order
 
     if (result != 0) {
         // The current sort role was sufficient to define an order


@@ -1321,14 +2165,13 @@ int KFileItemModel::sortRoleCompare(const ItemData* a, const ItemData* b) const
     }
 
     // Fallback #1: Compare the text of the items
     }
 
     // Fallback #1: Compare the text of the items

-    result = stringCompare(itemA.text(), itemB.text());
+    result = stringCompare(itemA.text(), itemB.text(), collator);

     if (result != 0) {
         return result;
     }
 
     // Fallback #2: KFileItem::text() may not be unique in case UDS_DISPLAY_NAME is used
     if (result != 0) {
         return result;
     }
 
     // Fallback #2: KFileItem::text() may not be unique in case UDS_DISPLAY_NAME is used

-    result = stringCompare(itemA.name(m_caseSensitivity == Qt::CaseInsensitive),
-                           itemB.name(m_caseSensitivity == Qt::CaseInsensitive));
+    result = stringCompare(itemA.name(), itemB.name(), collator);

     if (result != 0) {
         return result;
     }
     if (result != 0) {
         return result;
     }


@@ -1339,252 +2182,40 @@ int KFileItemModel::sortRoleCompare(const ItemData* a, const ItemData* b) const
     return QString::compare(itemA.url().url(), itemB.url().url(), Qt::CaseSensitive);
 }
 
     return QString::compare(itemA.url().url(), itemB.url().url(), Qt::CaseSensitive);
 }
 

-void KFileItemModel::sort(QList<ItemData*>::iterator begin,
-                          QList<ItemData*>::iterator end)
-{   
-    // The implementation is based on qStableSortHelper() from qalgorithms.h
-    // Copyright (C) 2011 Nokia Corporation and/or its subsidiary(-ies).
-    // In opposite to qStableSort() it allows to use a member-function for the comparison of elements.
-    
-    const int span = end - begin;
-    if (span < 2) {
-        return;
-    }
-    
-    const QList<ItemData*>::iterator middle = begin + span / 2;
-    sort(begin, middle);
-    sort(middle, end);
-    merge(begin, middle, end);
-}
-
-void KFileItemModel::merge(QList<ItemData*>::iterator begin,
-                           QList<ItemData*>::iterator pivot,
-                           QList<ItemData*>::iterator end)
+int KFileItemModel::stringCompare(const QString &a, const QString &b, const QCollator &collator) const

 {
 {

-    // The implementation is based on qMerge() from qalgorithms.h
-    // Copyright (C) 2011 Nokia Corporation and/or its subsidiary(-ies).
-    
-    const int len1 = pivot - begin;
-    const int len2 = end - pivot;
-    
-    if (len1 == 0 || len2 == 0) {
-        return;
-    }
-    
-    if (len1 + len2 == 2) {
-        if (lessThan(*(begin + 1), *(begin))) {
-            qSwap(*begin, *(begin + 1));
-        }
-        return;
-    }
-    
-    QList<ItemData*>::iterator firstCut;
-    QList<ItemData*>::iterator secondCut;
-    int len2Half;
-    if (len1 > len2) {
-        const int len1Half = len1 / 2;
-        firstCut = begin + len1Half;
-        secondCut = lowerBound(pivot, end, *firstCut);
-        len2Half = secondCut - pivot;
-    } else {
-        len2Half = len2 / 2;
-        secondCut = pivot + len2Half;
-        firstCut = upperBound(begin, pivot, *secondCut);
-    }
-    
-    reverse(firstCut, pivot);
-    reverse(pivot, secondCut);
-    reverse(firstCut, secondCut);
-    
-    const QList<ItemData*>::iterator newPivot = firstCut + len2Half;
-    merge(begin, firstCut, newPivot);
-    merge(newPivot, secondCut, end);
-}
-
-QList<KFileItemModel::ItemData*>::iterator KFileItemModel::lowerBound(QList<ItemData*>::iterator begin,
-                                                                      QList<ItemData*>::iterator end,
-                                                                      const ItemData* value)
-{
-    // The implementation is based on qLowerBound() from qalgorithms.h
-    // Copyright (C) 2011 Nokia Corporation and/or its subsidiary(-ies).
-    
-    QList<ItemData*>::iterator middle;
-    int n = int(end - begin);
-    int half;
-
-    while (n > 0) {
-        half = n >> 1;
-        middle = begin + half;
-        if (lessThan(*middle, value)) {
-            begin = middle + 1;
-            n -= half + 1;
-        } else {
-            n = half;
-        }
-    }
-    return begin;
-}
+    QMutexLocker collatorLock(s_collatorMutex());

 
 

-QList<KFileItemModel::ItemData*>::iterator KFileItemModel::upperBound(QList<ItemData*>::iterator begin,
-                                                                      QList<ItemData*>::iterator end,
-                                                                      const ItemData* value)
-{
-    // The implementation is based on qUpperBound() from qalgorithms.h
-    // Copyright (C) 2011 Nokia Corporation and/or its subsidiary(-ies).
-    
-    QList<ItemData*>::iterator middle;
-    int n = end - begin;
-    int half;
-
-    while (n > 0) {
-        half = n >> 1;
-        middle = begin + half;
-        if (lessThan(value, *middle)) {
-            n = half;
-        } else {
-            begin = middle + 1;
-            n -= half + 1;
-        }
-    }
-    return begin;
-}
-
-void KFileItemModel::reverse(QList<ItemData*>::iterator begin,
-                             QList<ItemData*>::iterator end)
-{
-    // The implementation is based on qReverse() from qalgorithms.h
-    // Copyright (C) 2011 Nokia Corporation and/or its subsidiary(-ies).
-    
-    --end;
-    while (begin < end) {
-        qSwap(*begin++, *end--);
-    }    
-}
-
-int KFileItemModel::stringCompare(const QString& a, const QString& b) const
-{
-    // Taken from KDirSortFilterProxyModel (kdelibs/kfile/kdirsortfilterproxymodel.*)
-    // Copyright (C) 2006 by Peter Penz <peter.penz@gmx.at>
-    // Copyright (C) 2006 by Dominic Battre <dominic@battre.de>
-    // Copyright (C) 2006 by Martin Pool <mbp@canonical.com>
-
-    if (m_caseSensitivity == Qt::CaseInsensitive) {
-        const int result = m_naturalSorting ? KStringHandler::naturalCompare(a, b, Qt::CaseInsensitive)
-                                            : QString::compare(a, b, Qt::CaseInsensitive);
-        if (result != 0) {
-            // Only return the result, if the strings are not equal. If they are equal by a case insensitive
-            // comparison, still a deterministic sort order is required. A case sensitive
-            // comparison is done as fallback.
-            return result;
-        }
+    if (m_naturalSorting) {
+        return collator.compare(a, b);

     }
 
     }
 

-    return m_naturalSorting ? KStringHandler::naturalCompare(a, b, Qt::CaseSensitive)
-                            : QString::compare(a, b, Qt::CaseSensitive);
-}
-
-int KFileItemModel::expansionLevelsCompare(const ItemData* a, const ItemData* b) const
-{
-    const KUrl urlA = a->item.url();
-    const KUrl urlB = b->item.url();
-    if (urlA.directory() == urlB.directory()) {
-        // Both items have the same directory as parent
-        return 0;
-    }
-
-    // Check whether one item is the parent of the other item
-    if (urlA.isParentOf(urlB)) {
-        return (sortOrder() == Qt::AscendingOrder) ? -1 : +1;
-    } else if (urlB.isParentOf(urlA)) {
-        return (sortOrder() == Qt::AscendingOrder) ? +1 : -1;
-    }
-
-    // Determine the maximum common path of both items and
-    // remember the index in 'index'
-    const QString pathA = urlA.path();
-    const QString pathB = urlB.path();
-
-    const int maxIndex = qMin(pathA.length(), pathB.length()) - 1;
-    int index = 0;
-    while (index <= maxIndex && pathA.at(index) == pathB.at(index)) {
-        ++index;
-    }
-    if (index > maxIndex) {
-        index = maxIndex;
-    }
-    while ((pathA.at(index) != QLatin1Char('/') || pathB.at(index) != QLatin1Char('/')) && index > 0) {
-        --index;
-    }
-
-    // Determine the first sub-path after the common path and
-    // check whether it represents a directory or already a file
-    bool isDirA = true;
-    const QString subPathA = subPath(a->item, pathA, index, &isDirA);
-    bool isDirB = true;
-    const QString subPathB = subPath(b->item, pathB, index, &isDirB);
-
-    if (isDirA && !isDirB) {
-        return (sortOrder() == Qt::AscendingOrder) ? -1 : +1;
-    } else if (!isDirA && isDirB) {
-        return (sortOrder() == Qt::AscendingOrder) ? +1 : -1;
-    }
-
-    // Compare the items of the parents that represent the first
-    // different path after the common path.
-    const KUrl parentUrlA(pathA.left(index) + subPathA);
-    const KUrl parentUrlB(pathB.left(index) + subPathB);
-
-    const ItemData* parentA = a;
-    while (parentA && parentA->item.url() != parentUrlA) {
-        parentA = parentA->parent;
-    }
-
-    const ItemData* parentB = b;
-    while (parentB && parentB->item.url() != parentUrlB) {
-        parentB = parentB->parent;
-    }
-
-    if (parentA && parentB) {
-        return sortRoleCompare(parentA, parentB);
+    const int result = QString::compare(a, b, collator.caseSensitivity());
+    if (result != 0 || collator.caseSensitivity() == Qt::CaseSensitive) {
+        // Only return the result, if the strings are not equal. If they are equal by a case insensitive
+        // comparison, still a deterministic sort order is required. A case sensitive
+        // comparison is done as fallback.
+        return result;

     }
 
     }
 

-    kWarning() << "Child items without parent detected:" << a->item.url() << b->item.url();
-    return QString::compare(urlA.url(), urlB.url(), Qt::CaseSensitive);
-}
-
-QString KFileItemModel::subPath(const KFileItem& item,
-                                const QString& itemPath,
-                                int start,
-                                bool* isDir) const
-{
-    Q_ASSERT(isDir);
-    const int pathIndex = itemPath.indexOf('/', start + 1);
-    *isDir = (pathIndex > 0) || item.isDir();
-    return itemPath.mid(start, pathIndex - start);
-}
-
-bool KFileItemModel::useMaximumUpdateInterval() const
-{
-    const KDirLister* dirLister = m_dirLister.data();
-    return dirLister && !dirLister->url().isLocalFile();
+    return QString::compare(a, b, Qt::CaseSensitive);

 }
 
 }
 

-QList<QPair<int, QVariant> > KFileItemModel::nameRoleGroups() const
+QList<QPair<int, QVariant>> KFileItemModel::nameRoleGroups() const

 {
     Q_ASSERT(!m_itemData.isEmpty());
 
     const int maxIndex = count() - 1;
 {
     Q_ASSERT(!m_itemData.isEmpty());
 
     const int maxIndex = count() - 1;

-    QList<QPair<int, QVariant> > groups;
+    QList<QPair<int, QVariant>> groups;

 
     QString groupValue;
     QChar firstChar;
 
     QString groupValue;
     QChar firstChar;

-    bool isLetter = false;

     for (int i = 0; i <= maxIndex; ++i) {
         if (isChildItem(i)) {
             continue;
         }
 
     for (int i = 0; i <= maxIndex; ++i) {
         if (isChildItem(i)) {
             continue;
         }
 

-        const QString name = m_itemData.at(i)->values.value("name").toString();
+        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();
 
         // Use the first character of the name as group indication
         QChar newFirstChar = name.at(0).toUpper();


@@ -1594,31 +2225,42 @@ QList<QPair<int, QVariant> > KFileItemModel::nameRoleGroups() const
 
         if (firstChar != newFirstChar) {
             QString newGroupValue;
 
         if (firstChar != newFirstChar) {
             QString newGroupValue;

-            if (newFirstChar >= QLatin1Char('A') && newFirstChar <= QLatin1Char('Z')) {
-                // Apply group 'A' - 'Z'
-                newGroupValue = newFirstChar;
-                isLetter = true;
+            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));
+                        }
+                    }
+
+                    auto localeAwareLessThan = [this](QChar c1, QChar c2) -> bool {
+                        return m_collator.compare(c1, c2) < 0;
+                    };
+
+                    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;
+                    }
+
+                } else {
+                    // Symbols from non Latin-based scripts
+                    newGroupValue = newFirstChar;
+                }

             } 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 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");

-                isLetter = false;

             } else {
             } else {

-                if (isLetter) {
-                    // If the current group is 'A' - 'Z' check whether a locale character
-                    // fits into the existing group.
-                    // TODO: This does not work in the case if e.g. the group 'O' starts with
-                    // an umlaut 'O' -> provide unit-test to document this known issue
-                    const QChar prevChar(firstChar.unicode() - ushort(1));
-                    const QChar nextChar(firstChar.unicode() + ushort(1));
-                    const QString currChar(newFirstChar);
-                    const bool partOfCurrentGroup = currChar.localeAwareCompare(prevChar) > 0 &&
-                                                    currChar.localeAwareCompare(nextChar) < 0;
-                    if (partOfCurrentGroup) {
-                        continue;
-                    }
-                }

                 newGroupValue = i18nc("@title:group", "Others");
                 newGroupValue = i18nc("@title:group", "Others");

-                isLetter = false;

             }
 
             if (newGroupValue != groupValue) {
             }
 
             if (newGroupValue != groupValue) {


@@ -1632,12 +2274,12 @@ QList<QPair<int, QVariant> > KFileItemModel::nameRoleGroups() const
     return groups;
 }
 
     return groups;
 }
 

-QList<QPair<int, QVariant> > KFileItemModel::sizeRoleGroups() const
+QList<QPair<int, QVariant>> KFileItemModel::sizeRoleGroups() const

 {
     Q_ASSERT(!m_itemData.isEmpty());
 
     const int maxIndex = count() - 1;
 {
     Q_ASSERT(!m_itemData.isEmpty());
 
     const int maxIndex = count() - 1;

-    QList<QPair<int, QVariant> > groups;
+    QList<QPair<int, QVariant>> groups;

 
     QString groupValue;
     for (int i = 0; i <= maxIndex; ++i) {
 
     QString groupValue;
     for (int i = 0; i <= maxIndex; ++i) {


@@ -1645,17 +2287,25 @@ QList<QPair<int, QVariant> > KFileItemModel::sizeRoleGroups() const
             continue;
         }
 
             continue;
         }
 

-        const KFileItem& item = m_itemData.at(i)->item;
-        const KIO::filesize_t fileSize = !item.isNull() ? item.size() : ~0U;
+        const KFileItem &item = m_itemData.at(i)->item;
+        KIO::filesize_t fileSize = !item.isNull() ? item.size() : ~0U;

         QString newGroupValue;
         if (!item.isNull() && item.isDir()) {
         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");
-        } else {
-            newGroupValue = i18nc("@title:group Size", "Big");
+            if (DetailsModeSettings::directorySizeCount() || m_sortDirsFirst) {
+                newGroupValue = i18nc("@title:group Size", "Folders");
+            } else {
+                fileSize = m_itemData.at(i)->values.value("size").toULongLong();
+            }
+        }
+
+        if (newGroupValue.isEmpty()) {
+            if (fileSize < 5 * 1024 * 1024) { // < 5 MB
+                newGroupValue = i18nc("@title:group Size", "Small");
+            } else if (fileSize < 10 * 1024 * 1024) { // < 10 MB
+                newGroupValue = i18nc("@title:group Size", "Medium");
+            } else {
+                newGroupValue = i18nc("@title:group Size", "Big");
+            }

         }
 
         if (newGroupValue != groupValue) {
         }
 
         if (newGroupValue != groupValue) {


@@ -1667,61 +2317,54 @@ QList<QPair<int, QVariant> > KFileItemModel::sizeRoleGroups() const
     return groups;
 }
 
     return groups;
 }
 

-QList<QPair<int, QVariant> > KFileItemModel::dateRoleGroups() const
+QList<QPair<int, QVariant>> KFileItemModel::timeRoleGroups(const std::function<QDateTime(const ItemData *)> &fileTimeCb) const

 {
     Q_ASSERT(!m_itemData.isEmpty());
 
     const int maxIndex = count() - 1;
 {
     Q_ASSERT(!m_itemData.isEmpty());
 
     const int maxIndex = count() - 1;

-    QList<QPair<int, QVariant> > groups;
+    QList<QPair<int, QVariant>> groups;

 
 

-    const QDate currentDate = KDateTime::currentLocalDateTime().date();
+    const QDate currentDate = QDate::currentDate();

 
 

-    int yearForCurrentWeek = 0;
-    int currentWeek = currentDate.weekNumber(&yearForCurrentWeek);
-    if (yearForCurrentWeek == currentDate.year() + 1) {
-        currentWeek = 53;
-    }
-
-    QDate previousModifiedDate;
+    QDate previousFileDate;

     QString groupValue;
     for (int i = 0; i <= maxIndex; ++i) {
         if (isChildItem(i)) {
             continue;
         }
 
     QString groupValue;
     for (int i = 0; i <= maxIndex; ++i) {
         if (isChildItem(i)) {
             continue;
         }
 

-        const KDateTime modifiedTime = m_itemData.at(i)->item.time(KFileItem::ModificationTime);
-        const QDate modifiedDate = modifiedTime.date();
-        if (modifiedDate == previousModifiedDate) {
+        const QDateTime fileTime = fileTimeCb(m_itemData.at(i));
+        const QDate fileDate = fileTime.date();
+        if (fileDate == previousFileDate) {

             // The current item is in the same group as the previous item
             continue;
         }
             // The current item is in the same group as the previous item
             continue;
         }

-        previousModifiedDate = modifiedDate;
-
-        const int daysDistance = modifiedDate.daysTo(currentDate);
+        previousFileDate = fileDate;

 
 

-        int yearForModifiedWeek = 0;
-        int modifiedWeek = modifiedDate.weekNumber(&yearForModifiedWeek);
-        if (yearForModifiedWeek == modifiedDate.year() + 1) {
-            modifiedWeek = 53;
-        }
+        const int daysDistance = fileDate.daysTo(currentDate);

 
         QString newGroupValue;
 
         QString newGroupValue;

-        if (currentDate.year() == modifiedDate.year() && currentDate.month() == modifiedDate.month()) {
-            if (modifiedWeek > currentWeek) {
-                // Usecase: modified date = 2010-01-01, current date = 2010-01-22
-                //          modified week = 53,         current week = 3
-                modifiedWeek = 0;
-            }
-            switch (currentWeek - modifiedWeek) {
+        if (currentDate.year() == fileDate.year() && currentDate.month() == fileDate.month()) {
+            switch (daysDistance / 7) {

             case 0:
                 switch (daysDistance) {
             case 0:
                 switch (daysDistance) {

-                case 0:  newGroupValue = i18nc("@title:group Date", "Today"); break;
-                case 1:  newGroupValue = i18nc("@title:group Date", "Yesterday"); break;
-                default: newGroupValue = modifiedTime.toString(i18nc("@title:group The week day name: %A", "%A"));
+                case 0:
+                    newGroupValue = i18nc("@title:group Date", "Today");
+                    break;
+                case 1:
+                    newGroupValue = 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);

                 }
                 break;
             case 1:
                 }
                 break;
             case 1:

-                newGroupValue = i18nc("@title:group Date", "Last Week");
+                newGroupValue = i18nc("@title:group Date", "One Week Ago");

                 break;
             case 2:
                 newGroupValue = i18nc("@title:group Date", "Two Weeks Ago");
                 break;
             case 2:
                 newGroupValue = i18nc("@title:group Date", "Two Weeks Ago");


@@ -1738,22 +2381,135 @@ QList<QPair<int, QVariant> > KFileItemModel::dateRoleGroups() const
             }
         } else {
             const QDate lastMonthDate = currentDate.addMonths(-1);
             }
         } else {
             const QDate lastMonthDate = currentDate.addMonths(-1);

-            if  (lastMonthDate.year() == modifiedDate.year() && lastMonthDate.month() == modifiedDate.month()) {
+            if (lastMonthDate.year() == fileDate.year() && lastMonthDate.month() == fileDate.month()) {

                 if (daysDistance == 1) {
                 if (daysDistance == 1) {

-                    newGroupValue = modifiedTime.toString(i18nc("@title:group Date: %B is full month name in current locale, and %Y is full year number", "Yesterday (%B, %Y)"));
+                    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 "
+                            "\"'Yesterday' (MMMM, yyyy)\" with context @title:group Date",
+                            "%1",
+                            newGroupValue);
+                    } 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);
+                    }

                 } else if (daysDistance <= 7) {
                 } else if (daysDistance <= 7) {

-                    newGroupValue = modifiedTime.toString(i18nc("@title:group The week day name: %A, %B is full month name in current locale, and %Y is full year number", "%A (%B, %Y)"));
+                    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 "
+                        "\"dddd (MMMM, yyyy)\" with context @title:group Date",
+                        "%1",
+                        newGroupValue);

                 } else if (daysDistance <= 7 * 2) {
                 } else if (daysDistance <= 7 * 2) {

-                    newGroupValue = modifiedTime.toString(i18nc("@title:group Date: %B is full month name in current locale, and %Y is full year number", "Last Week (%B, %Y)"));
+                    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 "
+                            "\"'One Week Ago' (MMMM, yyyy)\" with context @title:group Date",
+                            "%1",
+                            newGroupValue);
+                    } 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);
+                    }

                 } else if (daysDistance <= 7 * 3) {
                 } else if (daysDistance <= 7 * 3) {

-                    newGroupValue = modifiedTime.toString(i18nc("@title:group Date: %B is full month name in current locale, and %Y is full year number", "Two Weeks Ago (%B, %Y)"));
+                    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 "
+                            "\"'Two Weeks Ago' (MMMM, yyyy)\" with context @title:group Date",
+                            "%1",
+                            newGroupValue);
+                    } 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);
+                    }

                 } else if (daysDistance <= 7 * 4) {
                 } else if (daysDistance <= 7 * 4) {

-                    newGroupValue = modifiedTime.toString(i18nc("@title:group Date: %B is full month name in current locale, and %Y is full year number", "Three Weeks Ago (%B, %Y)"));
+                    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 "
+                            "\"'Three Weeks Ago' (MMMM, yyyy)\" with context @title:group Date",
+                            "%1",
+                            newGroupValue);
+                    } 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);
+                    }

                 } else {
                 } else {

-                    newGroupValue = modifiedTime.toString(i18nc("@title:group Date: %B is full month name in current locale, and %Y is full year number", "Earlier on %B, %Y"));
+                    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 "
+                            "\"'Earlier on' MMMM, yyyy\" with context @title:group Date",
+                            "%1",
+                            newGroupValue);
+                    } 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);
+                    }

                 }
             } else {
                 }
             } else {

-                newGroupValue = modifiedTime.toString(i18nc("@title:group The month and year: %B is full month name in current locale, and %Y is full year number", "%B, %Y"));
+                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 "
+                    "\"MMMM, yyyy\" with context @title:group Date",
+                    "%1",
+                    newGroupValue);

             }
         }
 
             }
         }
 


@@ -1766,12 +2522,12 @@ QList<QPair<int, QVariant> > KFileItemModel::dateRoleGroups() const
     return groups;
 }
 
     return groups;
 }
 

-QList<QPair<int, QVariant> > KFileItemModel::permissionRoleGroups() const
+QList<QPair<int, QVariant>> KFileItemModel::permissionRoleGroups() const

 {
     Q_ASSERT(!m_itemData.isEmpty());
 
     const int maxIndex = count() - 1;
 {
     Q_ASSERT(!m_itemData.isEmpty());
 
     const int maxIndex = count() - 1;

-    QList<QPair<int, QVariant> > groups;
+    QList<QPair<int, QVariant>> groups;

 
     QString permissionsString;
     QString groupValue;
 
     QString permissionsString;
     QString groupValue;


@@ -1780,14 +2536,14 @@ QList<QPair<int, QVariant> > KFileItemModel::permissionRoleGroups() const
             continue;
         }
 
             continue;
         }
 

-        const ItemData* itemData = m_itemData.at(i);
+        const ItemData *itemData = m_itemData.at(i);

         const QString newPermissionsString = itemData->values.value("permissions").toString();
         if (newPermissionsString == permissionsString) {
             continue;
         }
         permissionsString = newPermissionsString;
 
         const QString newPermissionsString = itemData->values.value("permissions").toString();
         if (newPermissionsString == permissionsString) {
             continue;
         }
         permissionsString = newPermissionsString;
 

-        const QFileInfo info(itemData->item.url().pathOrUrl());
+        const QFileInfo info(itemData->item.url().toLocalFile());

 
         // Set user string
         QString user;
 
         // Set user string
         QString user;


@@ -1838,19 +2594,19 @@ QList<QPair<int, QVariant> > KFileItemModel::permissionRoleGroups() const
     return groups;
 }
 
     return groups;
 }
 

-QList<QPair<int, QVariant> > KFileItemModel::ratingRoleGroups() const
+QList<QPair<int, QVariant>> KFileItemModel::ratingRoleGroups() const

 {
     Q_ASSERT(!m_itemData.isEmpty());
 
     const int maxIndex = count() - 1;
 {
     Q_ASSERT(!m_itemData.isEmpty());
 
     const int maxIndex = count() - 1;

-    QList<QPair<int, QVariant> > groups;
+    QList<QPair<int, QVariant>> groups;

 
 

-    int groupValue;
+    int groupValue = -1;

     for (int i = 0; i <= maxIndex; ++i) {
         if (isChildItem(i)) {
             continue;
         }
     for (int i = 0; i <= maxIndex; ++i) {
         if (isChildItem(i)) {
             continue;
         }

-        const int newGroupValue = m_itemData.at(i)->values.value("rating").toInt();
+        const int newGroupValue = m_itemData.at(i)->values.value("rating", 0).toInt();

         if (newGroupValue != groupValue) {
             groupValue = newGroupValue;
             groups.append(QPair<int, QVariant>(i, newGroupValue));
         if (newGroupValue != groupValue) {
             groupValue = newGroupValue;
             groups.append(QPair<int, QVariant>(i, newGroupValue));


@@ -1860,43 +2616,198 @@ QList<QPair<int, QVariant> > KFileItemModel::ratingRoleGroups() const
     return groups;
 }
 
     return groups;
 }
 

-QList<QPair<int, QVariant> > KFileItemModel::genericStringRoleGroups(const QByteArray& role) const
+QList<QPair<int, QVariant>> KFileItemModel::genericStringRoleGroups(const QByteArray &role) const

 {
     Q_ASSERT(!m_itemData.isEmpty());
 
     const int maxIndex = count() - 1;
 {
     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;
     for (int i = 0; i <= maxIndex; ++i) {
         if (isChildItem(i)) {
             continue;
         }
         const QString newGroupValue = m_itemData.at(i)->values.value(role).toString();
     QString groupValue;
     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) {
+        if (newGroupValue != groupValue || isFirstGroupValue) {

             groupValue = newGroupValue;
             groups.append(QPair<int, QVariant>(i, newGroupValue));
             groupValue = newGroupValue;
             groups.append(QPair<int, QVariant>(i, newGroupValue));

+            isFirstGroupValue = false;

         }
     }
 
     return groups;
 }
 
         }
     }
 
     return groups;
 }
 

-KFileItemList KFileItemModel::childItems(const KFileItem& item) const
+void KFileItemModel::emitSortProgress(int resolvedCount)
+{
+    // Be tolerant against a resolvedCount with a wrong range.
+    // Although there should not be a case where KFileItemModelRolesUpdater
+    // (= caller) provides a wrong range, it is important to emit
+    // a useful progress information even if there is an unexpected
+    // implementation issue.
+
+    const int itemCount = count();
+    if (resolvedCount >= itemCount) {
+        m_sortingProgressPercent = -1;
+        if (m_resortAllItemsTimer->isActive()) {
+            m_resortAllItemsTimer->stop();
+            resortAllItems();
+        }
+
+        Q_EMIT directorySortingProgress(100);
+    } else if (itemCount > 0) {
+        resolvedCount = qBound(0, resolvedCount, itemCount);
+
+        const int progress = resolvedCount * 100 / itemCount;
+        if (m_sortingProgressPercent != progress) {
+            m_sortingProgressPercent = progress;
+            Q_EMIT directorySortingProgress(progress);
+        }
+    }
+}
+
+const KFileItemModel::RoleInfoMap *KFileItemModel::rolesInfoMap(int &count)
+{
+    static const RoleInfoMap rolesInfoMap[] = {
+    //  |         role           |        roleType        |                role translation         |         group translation                     | requires Baloo | requires indexer
+        { nullptr,               NoRole,                  KLazyLocalizedString(),                    KLazyLocalizedString(),                            false,           false },
+        { "text",                NameRole,                kli18nc("@label", "Name"),                 KLazyLocalizedString(),                            false,           false },
+        { "size",                SizeRole,                kli18nc("@label", "Size"),                 KLazyLocalizedString(),                            false,           false },
+        { "modificationtime",    ModificationTimeRole,    kli18nc("@label", "Modified"),             KLazyLocalizedString(),                            false,           false },
+        { "creationtime",        CreationTimeRole,        kli18nc("@label", "Created"),              KLazyLocalizedString(),                            false,           false },
+        { "accesstime",          AccessTimeRole,          kli18nc("@label", "Accessed"),             KLazyLocalizedString(),                            false,           false },
+        { "type",                TypeRole,                kli18nc("@label", "Type"),                 KLazyLocalizedString(),                            false,           false },
+        { "rating",              RatingRole,              kli18nc("@label", "Rating"),               KLazyLocalizedString(),                            true,            false },
+        { "tags",                TagsRole,                kli18nc("@label", "Tags"),                 KLazyLocalizedString(),                            true,            false },
+        { "comment",             CommentRole,             kli18nc("@label", "Comment"),              KLazyLocalizedString(),                            true,            false },
+        { "title",               TitleRole,               kli18nc("@label", "Title"),                kli18nc("@label", "Document"),                     true,            true  },
+        { "author",              AuthorRole,              kli18nc("@label", "Author"),               kli18nc("@label", "Document"),                     true,            true  },
+        { "publisher",           PublisherRole,           kli18nc("@label", "Publisher"),            kli18nc("@label", "Document"),                     true,            true  },
+        { "pageCount",           PageCountRole,           kli18nc("@label", "Page Count"),           kli18nc("@label", "Document"),                     true,            true  },
+        { "wordCount",           WordCountRole,           kli18nc("@label", "Word Count"),           kli18nc("@label", "Document"),                     true,            true  },
+        { "lineCount",           LineCountRole,           kli18nc("@label", "Line Count"),           kli18nc("@label", "Document"),                     true,            true  },
+        { "imageDateTime",       ImageDateTimeRole,       kli18nc("@label", "Date Photographed"),    kli18nc("@label", "Image"),                        true,            true  },
+        { "dimensions",          DimensionsRole,          kli18nc("@label width x height", "Dimensions"), kli18nc("@label", "Image"),                   true,            true  },
+        { "width",               WidthRole,               kli18nc("@label", "Width"),                kli18nc("@label", "Image"),                        true,            true  },
+        { "height",              HeightRole,              kli18nc("@label", "Height"),               kli18nc("@label", "Image"),                        true,            true  },
+        { "orientation",         OrientationRole,         kli18nc("@label", "Orientation"),          kli18nc("@label", "Image"),                        true,            true  },
+        { "artist",              ArtistRole,              kli18nc("@label", "Artist"),               kli18nc("@label", "Audio"),                        true,            true  },
+        { "genre",               GenreRole,               kli18nc("@label", "Genre"),                kli18nc("@label", "Audio"),                        true,            true  },
+        { "album",               AlbumRole,               kli18nc("@label", "Album"),                kli18nc("@label", "Audio"),                        true,            true  },
+        { "duration",            DurationRole,            kli18nc("@label", "Duration"),             kli18nc("@label", "Audio"),                        true,            true  },
+        { "bitrate",             BitrateRole,             kli18nc("@label", "Bitrate"),              kli18nc("@label", "Audio"),                        true,            true  },
+        { "track",               TrackRole,               kli18nc("@label", "Track"),                kli18nc("@label", "Audio"),                        true,            true  },
+        { "releaseYear",         ReleaseYearRole,         kli18nc("@label", "Release Year"),         kli18nc("@label", "Audio"),                        true,            true  },
+        { "aspectRatio",         AspectRatioRole,         kli18nc("@label", "Aspect Ratio"),         kli18nc("@label", "Video"),                        true,            true  },
+        { "frameRate",           FrameRateRole,           kli18nc("@label", "Frame Rate"),           kli18nc("@label", "Video"),                        true,            true  },
+        { "path",                PathRole,                kli18nc("@label", "Path"),                 kli18nc("@label", "Other"),                        false,           false },
+        { "extension",           ExtensionRole,           kli18nc("@label", "File Extension"),       kli18nc("@label", "Other"),                        false,           false },
+        { "deletiontime",        DeletionTimeRole,        kli18nc("@label", "Deletion Time"),        kli18nc("@label", "Other"),                        false,           false },
+        { "destination",         DestinationRole,         kli18nc("@label", "Link Destination"),     kli18nc("@label", "Other"),                        false,           false },
+        { "originUrl",           OriginUrlRole,           kli18nc("@label", "Downloaded From"),      kli18nc("@label", "Other"),                        true,            false },
+        { "permissions",         PermissionsRole,         kli18nc("@label", "Permissions"),          kli18nc("@label", "Other"),                        false,           false },
+        { "owner",               OwnerRole,               kli18nc("@label", "Owner"),                kli18nc("@label", "Other"),                        false,           false },
+        { "group",               GroupRole,               kli18nc("@label", "User Group"),           kli18nc("@label", "Other"),                        false,           false },
+    };
+
+    count = sizeof(rolesInfoMap) / sizeof(RoleInfoMap);
+    return rolesInfoMap;
+}
+
+void KFileItemModel::determineMimeTypes(const KFileItemList &items, int timeout)
+{
+    QElapsedTimer timer;
+    timer.start();
+    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
+        // type. Some special code for setting the correct mime type for
+        // directories is in retrieveData().
+        if (!item.isDir()) {
+            item.determineMimeType();
+        }
+
+        if (timer.elapsed() > timeout) {
+            // Don't block the user interface, let the remaining items
+            // be resolved asynchronously.
+            return;
+        }
+    }
+}
+
+QByteArray KFileItemModel::sharedValue(const QByteArray &value)
+{
+    static QSet<QByteArray> pool;
+    const QSet<QByteArray>::const_iterator it = pool.constFind(value);
+
+    if (it != pool.constEnd()) {
+        return *it;
+    } else {
+        pool.insert(value);
+        return value;
+    }
+}
+
+bool KFileItemModel::isConsistent() const

 {
 {

-    KFileItemList items;
+    // m_items may contain less items than m_itemData because m_items
+    // is populated lazily, see KFileItemModel::index(const QUrl& url).
+    if (m_items.count() > m_itemData.count()) {
+        return false;
+    }
+
+    for (int i = 0, iMax = count(); i < iMax; ++i) {
+        // Check if m_items and m_itemData are consistent.
+        const KFileItem item = fileItem(i);
+        if (item.isNull()) {
+            qCWarning(DolphinDebug) << "Item" << i << "is null";
+            return false;
+        }
+
+        const int itemIndex = index(item);
+        if (itemIndex != i) {
+            qCWarning(DolphinDebug) << "Item" << i << "has a wrong index:" << itemIndex;
+            return false;
+        }
+
+        // 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);
+            return false;
+        }
+
+        // Check if all parent-child relationships are consistent.
+        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;
+                return false;
+            }

 
 

-    int index = m_items.value(item.url(), -1);
-    if (index >= 0) {
-        const int parentLevel = m_itemData.at(index)->values.value("expansionLevel").toInt();
-        ++index;
-        while (index < m_itemData.count() && m_itemData.at(index)->values.value("expansionLevel").toInt() > parentLevel) {
-            items.append(m_itemData.at(index)->item);
-            ++index;
+            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;
+                return false;
+            }

         }
     }
 
         }
     }
 

-    return items;
+    return true;

 }
 
 }
 

-#include "kfileitemmodel.moc"
+void KFileItemModel::slotListerError(KIO::Job *job)
+{
+    if (job->error() == 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."));
+    }
+}