diff --git a/src/gui/categoryfiltermodel.cpp b/src/gui/categoryfiltermodel.cpp
new file mode 100644
index 000000000..4ceb7693e
--- /dev/null
+++ b/src/gui/categoryfiltermodel.cpp
@@ -0,0 +1,442 @@
+/*
+ * Bittorrent Client using Qt and libtorrent.
+ * Copyright (C) 2016  Vladimir Golovnev <glassez@yandex.ru>
+ *
+ * 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.
+ *
+ * In addition, as a special exception, the copyright holders give permission to
+ * link this program with the OpenSSL project's "OpenSSL" library (or with
+ * modified versions of it that use the same license as the "OpenSSL" library),
+ * and distribute the linked executables. You must obey the GNU General Public
+ * License in all respects for all of the code used other than "OpenSSL".  If you
+ * modify file(s), you may extend this exception to your version of the file(s),
+ * but you are not obligated to do so. If you do not wish to do so, delete this
+ * exception statement from your version.
+ */
+
+#include "categoryfiltermodel.h"
+
+#include <QHash>
+#include <QIcon>
+
+#include "base/bittorrent/torrenthandle.h"
+#include "base/bittorrent/session.h"
+#include "guiiconprovider.h"
+
+class CategoryModelItem
+{
+public:
+    CategoryModelItem()
+        : m_parent(nullptr)
+        , m_torrentsCount(0)
+    {
+    }
+
+    CategoryModelItem(CategoryModelItem *parent, QString categoryName, int torrentsCount = 0)
+        : m_parent(nullptr)
+        , m_name(categoryName)
+        , m_torrentsCount(torrentsCount)
+    {
+        if (parent)
+            parent->addChild(m_name, this);
+    }
+
+    ~CategoryModelItem()
+    {
+        clear();
+        if (m_parent) {
+            m_parent->m_torrentsCount -= m_torrentsCount;
+            const QString uid = m_parent->m_children.key(this);
+            m_parent->m_children.remove(uid);
+            m_parent->m_childUids.removeOne(uid);
+        }
+    }
+
+    QString name() const
+    {
+        return m_name;
+    }
+
+    QString fullName() const
+    {
+        if (!m_parent || m_parent->name().isEmpty())
+            return m_name;
+
+        return QString("%1/%2").arg(m_parent->fullName()).arg(m_name);
+    }
+
+    CategoryModelItem *parent() const
+    {
+        return m_parent;
+    }
+
+    int torrentsCount() const
+    {
+        return m_torrentsCount;
+    }
+
+    void increaseTorrentsCount()
+    {
+        ++m_torrentsCount;
+        if (m_parent)
+            m_parent->increaseTorrentsCount();
+    }
+
+    void decreaseTorrentsCount()
+    {
+        --m_torrentsCount;
+        if (m_parent)
+            m_parent->decreaseTorrentsCount();
+    }
+
+    int pos() const
+    {
+        if (!m_parent) return -1;
+
+        return m_parent->m_childUids.indexOf(m_name);
+    }
+
+    bool hasChild(const QString &name) const
+    {
+        return m_children.contains(name);
+    }
+
+    int childCount() const
+    {
+        return m_children.count();
+    }
+
+    CategoryModelItem *child(const QString &uid) const
+    {
+        return m_children.value(uid);
+    }
+
+    CategoryModelItem *childAt(int index) const
+    {
+        if ((index < 0) || (index >= m_childUids.count()))
+            return nullptr;
+
+        return m_children[m_childUids[index]];
+    }
+
+    void addChild(const QString &uid, CategoryModelItem *item)
+    {
+        Q_ASSERT(item);
+        Q_ASSERT(!item->parent());
+        Q_ASSERT(!m_children.contains(uid));
+
+        item->m_parent = this;
+        m_children[uid] = item;
+        auto pos = std::lower_bound(m_childUids.begin(), m_childUids.end(), uid);
+        m_childUids.insert(pos, uid);
+        m_torrentsCount += item->torrentsCount();
+    }
+
+    void clear()
+    {
+        // use copy of m_children for qDeleteAll
+        // to avoid collision when child removes
+        // itself from parent children
+        qDeleteAll(decltype(m_children)(m_children));
+    }
+
+private:
+    CategoryModelItem *m_parent;
+    QString m_name;
+    int m_torrentsCount;
+    QHash<QString, CategoryModelItem *> m_children;
+    QStringList m_childUids;
+};
+
+namespace
+{
+    QString shortName(const QString &fullName)
+    {
+        int pos = fullName.lastIndexOf(QLatin1Char('/'));
+        if (pos >= 0)
+            return fullName.mid(pos + 1);
+        return fullName;
+    }
+}
+
+CategoryFilterModel::CategoryFilterModel(QObject *parent)
+    : QAbstractItemModel(parent)
+    , m_rootItem(new CategoryModelItem)
+{
+    auto session = BitTorrent::Session::instance();
+
+    connect(session, SIGNAL(categoryAdded(QString)), SLOT(categoryAdded(QString)));
+    connect(session, SIGNAL(categoryRemoved(QString)), SLOT(categoryRemoved(QString)));
+    connect(session, SIGNAL(torrentCategoryChanged(BitTorrent::TorrentHandle *const, QString))
+            , SLOT(torrentCategoryChanged(BitTorrent::TorrentHandle *const, QString)));
+    connect(session, SIGNAL(subcategoriesSupportChanged()), SLOT(subcategoriesSupportChanged()));
+    connect(session, SIGNAL(torrentAdded(BitTorrent::TorrentHandle *const))
+            , SLOT(torrentAdded(BitTorrent::TorrentHandle *const)));
+    connect(session, SIGNAL(torrentAboutToBeRemoved(BitTorrent::TorrentHandle *const))
+            , SLOT(torrentAboutToBeRemoved(BitTorrent::TorrentHandle *const)));
+
+    populate();
+}
+
+CategoryFilterModel::~CategoryFilterModel()
+{
+    delete m_rootItem;
+}
+
+int CategoryFilterModel::columnCount(const QModelIndex &) const
+{
+    return 1;
+}
+
+QVariant CategoryFilterModel::data(const QModelIndex &index, int role) const
+{
+    if (!index.isValid()) return QVariant();
+
+    auto item = static_cast<CategoryModelItem *>(index.internalPointer());
+
+    if ((index.column() == 0) && (role == Qt::DecorationRole)) {
+        return GuiIconProvider::instance()->getIcon("inode-directory");
+    }
+
+    if ((index.column() == 0) && (role == Qt::DisplayRole)) {
+        return QString(QStringLiteral("%1  (%2)"))
+                .arg(item->name()).arg(item->torrentsCount());
+    }
+
+    if ((index.column() == 0) && (role == Qt::UserRole)) {
+        return item->torrentsCount();
+    }
+
+    return QVariant();
+}
+
+Qt::ItemFlags CategoryFilterModel::flags(const QModelIndex &index) const
+{
+    if (!index.isValid()) return 0;
+
+    return Qt::ItemIsEnabled | Qt::ItemIsSelectable;
+}
+
+QVariant CategoryFilterModel::headerData(int section, Qt::Orientation orientation, int role) const
+{
+    if ((orientation == Qt::Horizontal) && (role == Qt::DisplayRole))
+        if (section == 0)
+            return tr("Categories");
+
+    return QVariant();
+}
+
+QModelIndex CategoryFilterModel::index(int row, int column, const QModelIndex &parent) const
+{
+    if (column > 0)
+        return QModelIndex();
+
+    if (parent.isValid() && (parent.column() != 0))
+        return QModelIndex();
+
+    auto parentItem = parent.isValid() ? static_cast<CategoryModelItem *>(parent.internalPointer())
+                                       : m_rootItem;
+    if (row < parentItem->childCount())
+        return createIndex(row, column, parentItem->childAt(row));
+
+    return QModelIndex();
+}
+
+QModelIndex CategoryFilterModel::parent(const QModelIndex &index) const
+{
+    if (!index.isValid())
+        return QModelIndex();
+
+    auto item = static_cast<CategoryModelItem *>(index.internalPointer());
+    if (!item) return QModelIndex();
+
+    return this->index(item->parent());
+}
+
+int CategoryFilterModel::rowCount(const QModelIndex &parent) const
+{
+    if (parent.column() > 0)
+        return 0;
+
+    if (!parent.isValid())
+        return m_rootItem->childCount();
+
+    auto item = static_cast<CategoryModelItem *>(parent.internalPointer());
+    if (!item) return 0;
+
+    return item->childCount();
+}
+
+QModelIndex CategoryFilterModel::index(const QString &categoryName) const
+{
+    return index(findItem(categoryName));
+}
+
+QString CategoryFilterModel::categoryName(const QModelIndex &index) const
+{
+    if (!index.isValid()) return QString();
+    return static_cast<CategoryModelItem *>(index.internalPointer())->fullName();
+}
+
+QModelIndex CategoryFilterModel::index(CategoryModelItem *item) const
+{
+    if (!item || !item->parent()) return QModelIndex();
+
+    return index(item->pos(), 0, index(item->parent()));
+}
+
+void CategoryFilterModel::categoryAdded(const QString &categoryName)
+{
+    CategoryModelItem *parent = m_rootItem;
+
+    if (m_isSubcategoriesEnabled) {
+        QStringList expanded = BitTorrent::Session::expandCategory(categoryName);
+        if (expanded.count() > 1)
+            parent = findItem(expanded[expanded.count() - 2]);
+    }
+
+    auto item = new CategoryModelItem(
+                parent, m_isSubcategoriesEnabled ? shortName(categoryName) : categoryName);
+
+    QModelIndex i = index(item);
+    beginInsertRows(i.parent(), i.row(), i.row());
+    endInsertRows();
+}
+
+void CategoryFilterModel::categoryRemoved(const QString &categoryName)
+{
+    auto item = findItem(categoryName);
+    if (item) {
+        QModelIndex i = index(item);
+        beginRemoveRows(i.parent(), i.row(), i.row());
+        delete item;
+        endRemoveRows();
+    }
+}
+
+void CategoryFilterModel::torrentAdded(BitTorrent::TorrentHandle *const torrent)
+{
+    CategoryModelItem *item = findItem(torrent->category());
+    Q_ASSERT(item);
+
+    item->increaseTorrentsCount();
+    m_rootItem->childAt(0)->increaseTorrentsCount();
+}
+
+void CategoryFilterModel::torrentAboutToBeRemoved(BitTorrent::TorrentHandle *const torrent)
+{
+    CategoryModelItem *item = findItem(torrent->category());
+    Q_ASSERT(item);
+
+    item->decreaseTorrentsCount();
+    m_rootItem->childAt(0)->decreaseTorrentsCount();
+}
+
+void CategoryFilterModel::torrentCategoryChanged(BitTorrent::TorrentHandle *const torrent, const QString &oldCategory)
+{
+    QModelIndex i;
+
+    auto item = findItem(oldCategory);
+    Q_ASSERT(item);
+
+    item->decreaseTorrentsCount();
+    i = index(item);
+    while (i.isValid()) {
+        emit dataChanged(i, i);
+        i = parent(i);
+    }
+
+    item = findItem(torrent->category());
+    Q_ASSERT(item);
+
+    item->increaseTorrentsCount();
+    i = index(item);
+    while (i.isValid()) {
+        emit dataChanged(i, i);
+        i = parent(i);
+    }
+}
+
+void CategoryFilterModel::subcategoriesSupportChanged()
+{
+    beginResetModel();
+    populate();
+    endResetModel();
+}
+
+void CategoryFilterModel::populate()
+{
+    m_rootItem->clear();
+
+    auto session = BitTorrent::Session::instance();
+    auto torrents = session->torrents();
+    m_isSubcategoriesEnabled = session->isSubcategoriesEnabled();
+
+    const QString UID_ALL;
+    const QString UID_UNCATEGORIZED(QChar(1));
+
+    // All torrents
+    m_rootItem->addChild(UID_ALL, new CategoryModelItem(nullptr, tr("All"), torrents.count()));
+
+    // Uncategorized torrents
+    using Torrent = BitTorrent::TorrentHandle;
+    m_rootItem->addChild(
+                UID_UNCATEGORIZED
+                , new CategoryModelItem(
+                    nullptr, tr("Uncategorized")
+                    , std::count_if(torrents.begin(), torrents.end()
+                                    , [](Torrent *torrent) { return torrent->category().isEmpty(); })));
+
+    using Torrent = BitTorrent::TorrentHandle;
+    foreach (const QString &category, session->categories()) {
+        if (m_isSubcategoriesEnabled) {
+            CategoryModelItem *parent = m_rootItem;
+            foreach (const QString &subcat, session->expandCategory(category)) {
+                const QString subcatName = shortName(subcat);
+                if (!parent->hasChild(subcatName)) {
+                    new CategoryModelItem(
+                                parent, subcatName
+                                , std::count_if(torrents.begin(), torrents.end()
+                                                , [subcat](Torrent *torrent) { return torrent->category() == subcat; }));
+                }
+                parent = parent->child(subcatName);
+            }
+        }
+        else {
+            new CategoryModelItem(
+                        m_rootItem, category
+                        , std::count_if(torrents.begin(), torrents.end()
+                                        , [category](Torrent *torrent) { return torrent->belongsToCategory(category); }));
+        }
+    }
+}
+
+CategoryModelItem *CategoryFilterModel::findItem(const QString &fullName) const
+{
+    if (fullName.isEmpty())
+        return m_rootItem->childAt(1); // "Uncategorized" item
+
+    if (!m_isSubcategoriesEnabled)
+        return m_rootItem->child(fullName);
+
+    CategoryModelItem *item = m_rootItem;
+    foreach (const QString &subcat, BitTorrent::Session::expandCategory(fullName)) {
+        const QString subcatName = shortName(subcat);
+        if (!item->hasChild(subcatName)) return nullptr;
+        item = item->child(subcatName);
+    }
+
+    return item;
+}
diff --git a/src/gui/categoryfiltermodel.h b/src/gui/categoryfiltermodel.h
new file mode 100644
index 000000000..df92eab57
--- /dev/null
+++ b/src/gui/categoryfiltermodel.h
@@ -0,0 +1,79 @@
+/*
+ * Bittorrent Client using Qt and libtorrent.
+ * Copyright (C) 2016  Vladimir Golovnev <glassez@yandex.ru>
+ *
+ * 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.
+ *
+ * In addition, as a special exception, the copyright holders give permission to
+ * link this program with the OpenSSL project's "OpenSSL" library (or with
+ * modified versions of it that use the same license as the "OpenSSL" library),
+ * and distribute the linked executables. You must obey the GNU General Public
+ * License in all respects for all of the code used other than "OpenSSL".  If you
+ * modify file(s), you may extend this exception to your version of the file(s),
+ * but you are not obligated to do so. If you do not wish to do so, delete this
+ * exception statement from your version.
+ */
+
+#ifndef CATEGORYFILTERMODEL_H
+#define CATEGORYFILTERMODEL_H
+
+#include <QAbstractItemModel>
+#include <QHash>
+#include <QModelIndex>
+
+namespace BitTorrent
+{
+    class TorrentHandle;
+}
+
+class CategoryModelItem;
+
+class CategoryFilterModel: public QAbstractItemModel
+{
+    Q_OBJECT
+
+public:
+    explicit CategoryFilterModel(QObject *parent = nullptr);
+    ~CategoryFilterModel();
+
+    int columnCount(const QModelIndex &parent = QModelIndex()) const override;
+    QVariant data(const QModelIndex &index, int role = Qt::DisplayRole) const override;
+    Qt::ItemFlags flags(const QModelIndex &index) const override;
+    QVariant headerData(int section, Qt::Orientation orientation, int role) const override;
+    QModelIndex index(int row, int column, const QModelIndex &parent = QModelIndex()) const override;
+    QModelIndex parent(const QModelIndex &index) const override;
+    int rowCount(const QModelIndex &parent = QModelIndex()) const override;
+
+    QModelIndex index(const QString &categoryName) const;
+    QString categoryName(const QModelIndex &index) const;
+
+private slots:
+    void categoryAdded(const QString &categoryName);
+    void categoryRemoved(const QString &categoryName);
+    void torrentAdded(BitTorrent::TorrentHandle *const torrent);
+    void torrentAboutToBeRemoved(BitTorrent::TorrentHandle *const torrent);
+    void torrentCategoryChanged(BitTorrent::TorrentHandle *const torrent, const QString &oldCategory);
+    void subcategoriesSupportChanged();
+
+private:
+    void populate();
+    QModelIndex index(CategoryModelItem *item) const;
+    CategoryModelItem *findItem(const QString &fullName) const;
+
+    bool m_isSubcategoriesEnabled;
+    CategoryModelItem *m_rootItem;
+};
+
+#endif // CATEGORYFILTERMODEL_H
diff --git a/src/gui/categoryfilterwidget.cpp b/src/gui/categoryfilterwidget.cpp
new file mode 100644
index 000000000..536086fe6
--- /dev/null
+++ b/src/gui/categoryfilterwidget.cpp
@@ -0,0 +1,269 @@
+/*
+ * Bittorrent Client using Qt and libtorrent.
+ * Copyright (C) 2016  Vladimir Golovnev <glassez@yandex.ru>
+ *
+ * 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.
+ *
+ * In addition, as a special exception, the copyright holders give permission to
+ * link this program with the OpenSSL project's "OpenSSL" library (or with
+ * modified versions of it that use the same license as the "OpenSSL" library),
+ * and distribute the linked executables. You must obey the GNU General Public
+ * License in all respects for all of the code used other than "OpenSSL".  If you
+ * modify file(s), you may extend this exception to your version of the file(s),
+ * but you are not obligated to do so. If you do not wish to do so, delete this
+ * exception statement from your version.
+ */
+
+#include "categoryfilterwidget.h"
+
+#include <QAction>
+#include <QHeaderView>
+#include <QLayout>
+#include <QMenu>
+#include <QMessageBox>
+
+#include "base/bittorrent/session.h"
+#include "base/utils/misc.h"
+#include "autoexpandabledialog.h"
+#include "categoryfiltermodel.h"
+#include "guiiconprovider.h"
+
+namespace
+{
+    QString getCategoryFilter(const CategoryFilterModel *const model, const QModelIndex &index)
+    {
+        QString categoryFilter; // Defaults to All
+        if (index.isValid()) {
+            if (!index.parent().isValid() && (index.row() == 1))
+                categoryFilter = ""; // Uncategorized
+            else if (index.parent().isValid() || (index.row() > 1))
+                categoryFilter = model->categoryName(index);
+        }
+
+        return categoryFilter;
+    }
+
+    bool isSpecialItem(const QModelIndex &index)
+    {
+        // the first two items at first level are special items:
+        // 'All' and 'Uncategorized'
+        return (!index.parent().isValid() && (index.row() <= 1));
+    }
+}
+
+CategoryFilterWidget::CategoryFilterWidget(QWidget *parent)
+    : QTreeView(parent)
+{
+    setModel(new CategoryFilterModel(this));
+    setFrameShape(QFrame::NoFrame);
+    setHorizontalScrollBarPolicy(Qt::ScrollBarAlwaysOff);
+    setVerticalScrollBarPolicy(Qt::ScrollBarAlwaysOff);
+    setSizePolicy(QSizePolicy::Expanding, QSizePolicy::Fixed);
+    setUniformRowHeights(true);
+    setHeaderHidden(true);
+    setIconSize(Utils::Misc::smallIconSize());
+#if defined(Q_OS_MAC)
+    setAttribute(Qt::WA_MacShowFocusRect, false);
+#endif
+    setContextMenuPolicy(Qt::CustomContextMenu);
+
+    connect(this, SIGNAL(collapsed(QModelIndex)), SLOT(callUpdateGeometry()));
+    connect(this, SIGNAL(expanded(QModelIndex)), SLOT(callUpdateGeometry()));
+    connect(this, SIGNAL(customContextMenuRequested(QPoint)), SLOT(showMenu(QPoint)));
+    connect(selectionModel(), SIGNAL(currentRowChanged(QModelIndex,QModelIndex))
+            , SLOT(onCurrentRowChanged(QModelIndex,QModelIndex)));
+    connect(model(), SIGNAL(modelReset()), SLOT(callUpdateGeometry()));
+}
+
+QString CategoryFilterWidget::currentCategory() const
+{
+    QModelIndex current;
+    auto selectedRows = selectionModel()->selectedRows();
+    if (!selectedRows.isEmpty())
+        current = selectedRows.first();
+
+    return getCategoryFilter(static_cast<CategoryFilterModel *>(model()), current);
+}
+
+void CategoryFilterWidget::onCurrentRowChanged(const QModelIndex &current, const QModelIndex &previous)
+{
+    Q_UNUSED(previous);
+
+    emit categoryChanged(getCategoryFilter(static_cast<CategoryFilterModel *>(model()), current));
+}
+
+void CategoryFilterWidget::showMenu(QPoint)
+{
+    QMenu menu(this);
+
+    QAction *addAct = menu.addAction(
+                          GuiIconProvider::instance()->getIcon("list-add")
+                          , tr("Add category..."));
+    connect(addAct, SIGNAL(triggered()), SLOT(addCategory()));
+
+    auto selectedRows = selectionModel()->selectedRows();
+    if (!selectedRows.empty() && !isSpecialItem(selectedRows.first())) {
+        if (BitTorrent::Session::instance()->isSubcategoriesEnabled()) {
+            QAction *addSubAct = menu.addAction(
+                        GuiIconProvider::instance()->getIcon("list-add")
+                        , tr("Add subcategory..."));
+            connect(addSubAct, SIGNAL(triggered()), SLOT(addSubcategory()));
+        }
+
+        QAction *removeAct = menu.addAction(
+                        GuiIconProvider::instance()->getIcon("list-remove")
+                        , tr("Remove category"));
+        connect(removeAct, SIGNAL(triggered()), SLOT(removeCategory()));
+    }
+
+    QAction *removeUnusedAct = menu.addAction(
+                                   GuiIconProvider::instance()->getIcon("list-remove")
+                                   , tr("Remove unused categories"));
+    connect(removeUnusedAct, SIGNAL(triggered()), SLOT(removeUnusedCategories()));
+
+    menu.addSeparator();
+
+    QAction *startAct = menu.addAction(
+                            GuiIconProvider::instance()->getIcon("media-playback-start")
+                            , tr("Resume torrents"));
+    connect(startAct, SIGNAL(triggered()), SIGNAL(actionResumeTorrentsTriggered()));
+
+    QAction *pauseAct = menu.addAction(
+                            GuiIconProvider::instance()->getIcon("media-playback-pause")
+                            , tr("Pause torrents"));
+    connect(pauseAct, SIGNAL(triggered()), SIGNAL(actionPauseTorrentsTriggered()));
+
+    QAction *deleteTorrentsAct = menu.addAction(
+                                     GuiIconProvider::instance()->getIcon("edit-delete")
+                                     , tr("Delete torrents"));
+    connect(deleteTorrentsAct, SIGNAL(triggered()), SIGNAL(actionDeleteTorrentsTriggered()));
+
+    menu.exec(QCursor::pos());
+}
+
+void CategoryFilterWidget::callUpdateGeometry()
+{
+    updateGeometry();
+}
+
+QSize CategoryFilterWidget::sizeHint() const
+{
+#ifdef QBT_USES_QT5
+    return viewportSizeHint();
+#else
+    int lastRow = model()->rowCount() - 1;
+    QModelIndex last = model()->index(lastRow, 0);
+    while ((lastRow >= 0) && isExpanded(last)) {
+        lastRow = model()->rowCount(last) - 1;
+        last = model()->index(lastRow, 0, last);
+    }
+    const QRect deepestRect = visualRect(last);
+
+    if (!deepestRect.isValid())
+        return viewport()->sizeHint();
+
+    return QSize(header()->length(), deepestRect.bottom() + 1);
+#endif
+}
+
+QSize CategoryFilterWidget::minimumSizeHint() const
+{
+    QSize size = sizeHint();
+    size.setWidth(6);
+    return size;
+}
+
+void CategoryFilterWidget::rowsInserted(const QModelIndex &parent, int start, int end)
+{
+    QTreeView::rowsInserted(parent, start, end);
+
+    // Expand all parents if the parent(s) of the node are not expanded.
+    QModelIndex p = parent;
+    while (p.isValid()) {
+        if (!isExpanded(p))
+            expand(p);
+        p = model()->parent(p);
+    }
+
+    updateGeometry();
+}
+
+QString CategoryFilterWidget::askCategoryName()
+{
+    bool ok;
+    QString category = "";
+    bool invalid;
+    do {
+        invalid = false;
+        category = AutoExpandableDialog::getText(
+                    this, tr("New Category"), tr("Category:"), QLineEdit::Normal, category, &ok);
+        if (ok && !category.isEmpty()) {
+            if (!BitTorrent::Session::isValidCategoryName(category)) {
+                QMessageBox::warning(
+                            this, tr("Invalid category name")
+                            , tr("Category name must not contain '\\'.\n"
+                                 "Category name must not start/end with '/'.\n"
+                                 "Category name must not contain '//' sequence."));
+                invalid = true;
+            }
+        }
+    } while (invalid);
+
+    return ok ? category : QString();
+}
+
+void CategoryFilterWidget::addCategory()
+{
+    const QString category = askCategoryName();
+    if (category.isEmpty()) return;
+
+    if (BitTorrent::Session::instance()->categories().contains(category))
+        QMessageBox::warning(this, tr("Category exists"), tr("Category name already exists."));
+    else
+        BitTorrent::Session::instance()->addCategory(category);
+}
+
+void CategoryFilterWidget::addSubcategory()
+{
+    const QString subcat = askCategoryName();
+    if (subcat.isEmpty()) return;
+
+    const QString category = QString(QStringLiteral("%1/%2")).arg(currentCategory()).arg(subcat);
+
+    if (BitTorrent::Session::instance()->categories().contains(category))
+        QMessageBox::warning(this, tr("Category exists")
+                             , tr("Subcategory name already exists in selected category."));
+    else
+        BitTorrent::Session::instance()->addCategory(category);
+}
+
+void CategoryFilterWidget::removeCategory()
+{
+    auto selectedRows = selectionModel()->selectedRows();
+    if (!selectedRows.empty() && !isSpecialItem(selectedRows.first())) {
+        BitTorrent::Session::instance()->removeCategory(
+                    static_cast<CategoryFilterModel *>(model())->categoryName(selectedRows.first()));
+        updateGeometry();
+    }
+}
+
+void CategoryFilterWidget::removeUnusedCategories()
+{
+    auto session = BitTorrent::Session::instance();
+    foreach (const QString &category, session->categories())
+        if (model()->data(static_cast<CategoryFilterModel *>(model())->index(category), Qt::UserRole) == 0)
+            session->removeCategory(category);
+    updateGeometry();
+}
diff --git a/src/gui/categoryfilterwidget.h b/src/gui/categoryfilterwidget.h
new file mode 100644
index 000000000..3cfe64e2f
--- /dev/null
+++ b/src/gui/categoryfilterwidget.h
@@ -0,0 +1,60 @@
+/*
+ * Bittorrent Client using Qt and libtorrent.
+ * Copyright (C) 2016  Vladimir Golovnev <glassez@yandex.ru>
+ *
+ * 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.
+ *
+ * In addition, as a special exception, the copyright holders give permission to
+ * link this program with the OpenSSL project's "OpenSSL" library (or with
+ * modified versions of it that use the same license as the "OpenSSL" library),
+ * and distribute the linked executables. You must obey the GNU General Public
+ * License in all respects for all of the code used other than "OpenSSL".  If you
+ * modify file(s), you may extend this exception to your version of the file(s),
+ * but you are not obligated to do so. If you do not wish to do so, delete this
+ * exception statement from your version.
+ */
+
+ #include <QTreeView>
+
+class CategoryFilterWidget: public QTreeView
+{
+    Q_OBJECT
+
+public:
+    explicit CategoryFilterWidget(QWidget *parent = nullptr);
+
+    QString currentCategory() const;
+
+signals:
+    void categoryChanged(const QString &categoryName);
+    void actionResumeTorrentsTriggered();
+    void actionPauseTorrentsTriggered();
+    void actionDeleteTorrentsTriggered();
+
+private slots:
+    void onCurrentRowChanged(const QModelIndex &current, const QModelIndex &previous);
+    void showMenu(QPoint);
+    void callUpdateGeometry();
+    void addCategory();
+    void addSubcategory();
+    void removeCategory();
+    void removeUnusedCategories();
+
+private:
+    QSize sizeHint() const override;
+    QSize minimumSizeHint() const override;
+    void rowsInserted(const QModelIndex &parent, int start, int end) override;
+    QString askCategoryName();
+};
diff --git a/src/gui/gui.pri b/src/gui/gui.pri
index c55e74fe3..62ad185eb 100644
--- a/src/gui/gui.pri
+++ b/src/gui/gui.pri
@@ -49,7 +49,9 @@ HEADERS += \
     $$PWD/search/searchlistdelegate.h \
     $$PWD/search/searchsortmodel.h \
     $$PWD/cookiesmodel.h \
-    $$PWD/cookiesdialog.h
+    $$PWD/cookiesdialog.h \
+    $$PWD/categoryfiltermodel.h \
+    $$PWD/categoryfilterwidget.h
 
 SOURCES += \
     $$PWD/mainwindow.cpp \
@@ -89,7 +91,9 @@ SOURCES += \
     $$PWD/search/searchlistdelegate.cpp \
     $$PWD/search/searchsortmodel.cpp \
     $$PWD/cookiesmodel.cpp \
-    $$PWD/cookiesdialog.cpp
+    $$PWD/cookiesdialog.cpp \
+    $$PWD/categoryfiltermodel.cpp \
+    $$PWD/categoryfilterwidget.cpp
 
 win32|macx {
     HEADERS += $$PWD/programupdater.h
diff --git a/src/gui/transferlistfilterswidget.cpp b/src/gui/transferlistfilterswidget.cpp
index 319fc36ec..b3c86b002 100644
--- a/src/gui/transferlistfilterswidget.cpp
+++ b/src/gui/transferlistfilterswidget.cpp
@@ -30,31 +30,32 @@
 
 #include "transferlistfilterswidget.h"
 
+#include <QCheckBox>
 #include <QDebug>
-#include <QListWidgetItem>
 #include <QIcon>
-#include <QVBoxLayout>
+#include <QListWidgetItem>
 #include <QMenu>
 #include <QMessageBox>
-#include <QCheckBox>
 #include <QScrollArea>
+#include <QVBoxLayout>
 
-#include "transferlistdelegate.h"
-#include "transferlistwidget.h"
-#include "base/preferences.h"
-#include "torrentmodel.h"
-#include "guiiconprovider.h"
-#include "base/utils/fs.h"
-#include "base/utils/string.h"
-#include "autoexpandabledialog.h"
-#include "base/torrentfilter.h"
-#include "base/bittorrent/trackerentry.h"
 #include "base/bittorrent/session.h"
 #include "base/bittorrent/torrenthandle.h"
+#include "base/bittorrent/trackerentry.h"
+#include "base/logger.h"
 #include "base/net/downloadmanager.h"
 #include "base/net/downloadhandler.h"
+#include "base/preferences.h"
+#include "base/torrentfilter.h"
+#include "base/utils/fs.h"
 #include "base/utils/misc.h"
-#include "base/logger.h"
+#include "base/utils/string.h"
+#include "autoexpandabledialog.h"
+#include "categoryfilterwidget.h"
+#include "guiiconprovider.h"
+#include "torrentmodel.h"
+#include "transferlistdelegate.h"
+#include "transferlistwidget.h"
 
 FiltersBase::FiltersBase(QWidget *parent, TransferListWidget *transferList)
     : QListWidget(parent)
@@ -177,266 +178,6 @@ void StatusFiltersWidget::handleNewTorrent(BitTorrent::TorrentHandle *const) {}
 
 void StatusFiltersWidget::torrentAboutToBeDeleted(BitTorrent::TorrentHandle *const) {}
 
-CategoryFiltersList::CategoryFiltersList(QWidget *parent, TransferListWidget *transferList)
-    : FiltersBase(parent, transferList)
-{
-    connect(BitTorrent::Session::instance(), SIGNAL(torrentCategoryChanged(BitTorrent::TorrentHandle *const, QString)), SLOT(torrentCategoryChanged(BitTorrent::TorrentHandle *const, QString)));
-    connect(BitTorrent::Session::instance(), SIGNAL(categoryAdded(QString)), SLOT(addItem(QString)));
-    connect(BitTorrent::Session::instance(), SIGNAL(categoryRemoved(QString)), SLOT(categoryRemoved(QString)));
-    connect(BitTorrent::Session::instance(), SIGNAL(subcategoriesSupportChanged()), SLOT(subcategoriesSupportChanged()));
-
-    refresh();
-    toggleFilter(Preferences::instance()->getCategoryFilterState());
-}
-
-void CategoryFiltersList::refresh()
-{
-    clear();
-    m_categories.clear();
-    m_totalTorrents = 0;
-    m_totalCategorized = 0;
-
-    QListWidgetItem *allCategories = new QListWidgetItem(this);
-    allCategories->setData(Qt::DisplayRole, QVariant(tr("All (0)", "this is for the category filter")));
-    allCategories->setData(Qt::DecorationRole, GuiIconProvider::instance()->getIcon("inode-directory"));
-    QListWidgetItem *noCategory = new QListWidgetItem(this);
-    noCategory->setData(Qt::DisplayRole, QVariant(tr("Uncategorized (0)")));
-    noCategory->setData(Qt::DecorationRole, GuiIconProvider::instance()->getIcon("inode-directory"));
-
-    foreach (const QString &category, BitTorrent::Session::instance()->categories())
-        addItem(category, false);
-
-    foreach (BitTorrent::TorrentHandle *const torrent, BitTorrent::Session::instance()->torrents())
-        handleNewTorrent(torrent);
-
-    setCurrentRow(0, QItemSelectionModel::SelectCurrent);
-}
-
-void CategoryFiltersList::addItem(const QString &category, bool hasTorrent)
-{
-    if (category.isEmpty()) return;
-
-    int torrentsInCategory = 0;
-    QListWidgetItem *categoryItem = 0;
-
-    bool exists = m_categories.contains(category);
-    if (exists) {
-        torrentsInCategory = m_categories.value(category);
-        categoryItem = item(rowFromCategory(category));
-    }
-    else {
-        categoryItem = new QListWidgetItem();
-        categoryItem->setData(Qt::DecorationRole, GuiIconProvider::instance()->getIcon("inode-directory"));
-    }
-
-    if (hasTorrent)
-        ++torrentsInCategory;
-
-    m_categories.insert(category, torrentsInCategory);
-    categoryItem->setText(QString("%1 (%2)").arg(category).arg(torrentsInCategory));
-    if (exists) return;
-
-    Q_ASSERT(count() >= 2);
-    int insPos = count();
-    for (int i = 2; i < count(); ++i) {
-        if (Utils::String::naturalCompareCaseSensitive(category, item(i)->text())) {
-            insPos = i;
-            break;
-        }
-    }
-    QListWidget::insertItem(insPos, categoryItem);
-    updateGeometry();
-}
-
-void CategoryFiltersList::removeItem(const QString &category)
-{
-    if (category.isEmpty()) return;
-
-    int torrentsInCategory = m_categories.value(category) - 1;
-    int row = rowFromCategory(category);
-    if (row < 2) return;
-
-    QListWidgetItem *categoryItem = item(row);
-    categoryItem->setText(QString("%1 (%2)").arg(category).arg(torrentsInCategory));
-    m_categories.insert(category, torrentsInCategory);
-}
-
-void CategoryFiltersList::removeSelectedCategory()
-{
-    QList<QListWidgetItem*> items = selectedItems();
-    if (items.size() == 0) return;
-
-    const int categoryRow = row(items.first());
-    if (categoryRow < 2) return;
-
-    BitTorrent::Session::instance()->removeCategory(categoryFromRow(categoryRow));
-    updateGeometry();
-}
-
-void CategoryFiltersList::removeUnusedCategories()
-{
-    foreach (const QString &category, m_categories.keys())
-        if (m_categories[category] == 0)
-            BitTorrent::Session::instance()->removeCategory(category);
-    updateGeometry();
-}
-
-void CategoryFiltersList::torrentCategoryChanged(BitTorrent::TorrentHandle *const torrent, const QString &oldCategory)
-{
-    qDebug() << "Torrent category changed from" << oldCategory << "to" << torrent->category();
-
-    if (torrent->category().isEmpty() && !oldCategory.isEmpty())
-        --m_totalCategorized;
-    else if (!torrent->category().isEmpty() && oldCategory.isEmpty())
-        ++m_totalCategorized;
-
-    item(1)->setText(tr("Uncategorized (%1)").arg(m_totalTorrents - m_totalCategorized));
-
-    if (BitTorrent::Session::instance()->isSubcategoriesEnabled()) {
-        foreach (const QString &subcategory, BitTorrent::Session::expandCategory(oldCategory))
-            removeItem(subcategory);
-        foreach (const QString &subcategory, BitTorrent::Session::expandCategory(torrent->category()))
-            addItem(subcategory, true);
-    }
-    else {
-        removeItem(oldCategory);
-        addItem(torrent->category(), true);
-    }
-}
-
-void CategoryFiltersList::categoryRemoved(const QString &category)
-{
-    m_categories.remove(category);
-    delete takeItem(rowFromCategory(category));
-}
-
-void CategoryFiltersList::subcategoriesSupportChanged()
-{
-    refresh();
-}
-
-void CategoryFiltersList::showMenu(QPoint)
-{
-    QMenu menu(this);
-    QAction *addAct = menu.addAction(GuiIconProvider::instance()->getIcon("list-add"), tr("Add category..."));
-    QAction *removeAct = 0;
-    QAction *removeUnusedAct = 0;
-    if (!selectedItems().empty() && row(selectedItems().first()) > 1)
-        removeAct = menu.addAction(GuiIconProvider::instance()->getIcon("list-remove"), tr("Remove category"));
-    removeUnusedAct = menu.addAction(GuiIconProvider::instance()->getIcon("list-remove"), tr("Remove unused categories"));
-    menu.addSeparator();
-    QAction *startAct = menu.addAction(GuiIconProvider::instance()->getIcon("media-playback-start"), tr("Resume torrents"));
-    QAction *pauseAct = menu.addAction(GuiIconProvider::instance()->getIcon("media-playback-pause"), tr("Pause torrents"));
-    QAction *deleteTorrentsAct = menu.addAction(GuiIconProvider::instance()->getIcon("edit-delete"), tr("Delete torrents"));
-    QAction *act = 0;
-    act = menu.exec(QCursor::pos());
-    if (!act)
-        return;
-
-    if (act == removeAct) {
-        removeSelectedCategory();
-    }
-    else if (act == removeUnusedAct) {
-        removeUnusedCategories();
-    }
-    else if (act == deleteTorrentsAct) {
-        transferList->deleteVisibleTorrents();
-    }
-    else if (act == startAct) {
-        transferList->startVisibleTorrents();
-    }
-    else if (act == pauseAct) {
-        transferList->pauseVisibleTorrents();
-    }
-    else if (act == addAct) {
-        bool ok;
-        QString category = "";
-        bool invalid;
-        do {
-            invalid = false;
-            category = AutoExpandableDialog::getText(this, tr("New Category"), tr("Category:"), QLineEdit::Normal, category, &ok);
-            if (ok && !category.isEmpty()) {
-                if (!BitTorrent::Session::isValidCategoryName(category)) {
-                    QMessageBox::warning(this, tr("Invalid category name"),
-                                         tr("Category name must not contain '\\'.\n"
-                                            "Category name must not start/end with '/'.\n"
-                                            "Category name must not contain '//' sequence."));
-                    invalid = true;
-                }
-                else {
-                    BitTorrent::Session::instance()->addCategory(category);
-                }
-            }
-        } while (invalid);
-    }
-}
-
-void CategoryFiltersList::applyFilter(int row)
-{
-    if (row >= 0)
-        transferList->applyCategoryFilter(categoryFromRow(row));
-}
-
-void CategoryFiltersList::handleNewTorrent(BitTorrent::TorrentHandle *const torrent)
-{
-    Q_ASSERT(torrent);
-
-    ++m_totalTorrents;
-    if (!torrent->category().isEmpty())
-        ++m_totalCategorized;
-
-    item(0)->setText(tr("All (%1)", "this is for the category filter").arg(m_totalTorrents));
-    item(1)->setText(tr("Uncategorized (%1)").arg(m_totalTorrents - m_totalCategorized));
-
-    if (BitTorrent::Session::instance()->isSubcategoriesEnabled()) {
-        foreach (const QString &subcategory, BitTorrent::Session::expandCategory(torrent->category()))
-            addItem(subcategory, true);
-    }
-    else {
-        addItem(torrent->category(), true);
-    }
-}
-
-void CategoryFiltersList::torrentAboutToBeDeleted(BitTorrent::TorrentHandle *const torrent)
-{
-    Q_ASSERT(torrent);
-
-    --m_totalTorrents;
-    if (!torrent->category().isEmpty())
-        --m_totalCategorized;
-
-    item(0)->setText(tr("All (%1)", "this is for the category filter").arg(m_totalTorrents));
-    item(1)->setText(tr("Uncategorized (%1)").arg(m_totalTorrents - m_totalCategorized));
-
-    if (BitTorrent::Session::instance()->isSubcategoriesEnabled()) {
-        foreach (const QString &subcategory, BitTorrent::Session::expandCategory(torrent->category()))
-            removeItem(subcategory);
-    }
-    else {
-        removeItem(torrent->category());
-    }
-}
-
-QString CategoryFiltersList::categoryFromRow(int row) const
-{
-    if (row == 0) return QString(); // All
-    if (row == 1) return QLatin1String(""); // Uncategorized
-
-    const QString &category = item(row)->text();
-    QStringList parts = category.split(" ");
-    Q_ASSERT(parts.size() >= 2);
-    parts.removeLast(); // Remove trailing number
-    return parts.join(" ");
-}
-
-int CategoryFiltersList::rowFromCategory(const QString &category) const
-{
-    Q_ASSERT(!category.isEmpty());
-    for (int i = 2; i<count(); ++i)
-        if (category == categoryFromRow(i)) return i;
-    return -1;
-}
-
 TrackerFiltersList::TrackerFiltersList(QWidget *parent, TransferListWidget *transferList)
     : FiltersBase(parent, transferList)
     , m_totalTorrents(0)
@@ -546,7 +287,7 @@ void TrackerFiltersList::removeItem(const QString &tracker, const QString &hash)
             return;
         }
         if (trackerItem != nullptr)
-            trackerItem->setText(tr("%1 (%2)", "openbittorrent.com (10)").arg(host).arg(tmp.size()));
+            trackerItem->setText(QString("%1 (%2)").arg(host).arg(tmp.size()));
     }
     else {
         row = 1;
@@ -787,7 +528,8 @@ QStringList TrackerFiltersList::getHashes(int row)
 
 TransferListFiltersWidget::TransferListFiltersWidget(QWidget *parent, TransferListWidget *transferList)
     : QFrame(parent)
-    , trackerFilters(0)
+    , m_transferList(transferList)
+    , m_trackerFilters(0)
 {
     Preferences* const pref = Preferences::instance();
 
@@ -826,50 +568,58 @@ TransferListFiltersWidget::TransferListFiltersWidget(QWidget *parent, TransferLi
     QCheckBox *categoryLabel = new QCheckBox(tr("Categories"), this);
     categoryLabel->setChecked(pref->getCategoryFilterState());
     categoryLabel->setFont(font);
+    connect(categoryLabel, SIGNAL(toggled(bool)), SLOT(onCategoryFilterStateChanged(bool)));
     frameLayout->addWidget(categoryLabel);
 
-    CategoryFiltersList *categoryFilters = new CategoryFiltersList(this, transferList);
-    frameLayout->addWidget(categoryFilters);
+    m_categoryFilterWidget = new CategoryFilterWidget(this);
+    connect(m_categoryFilterWidget, SIGNAL(actionDeleteTorrentsTriggered())
+            , transferList, SLOT(deleteVisibleTorrents()));
+    connect(m_categoryFilterWidget, SIGNAL(actionPauseTorrentsTriggered())
+            , transferList, SLOT(pauseVisibleTorrents()));
+    connect(m_categoryFilterWidget, SIGNAL(actionResumeTorrentsTriggered())
+            , transferList, SLOT(startVisibleTorrents()));
+    connect(m_categoryFilterWidget, SIGNAL(categoryChanged(QString))
+            , transferList, SLOT(applyCategoryFilter(QString)));
+    onCategoryFilterStateChanged(pref->getCategoryFilterState());
+    frameLayout->addWidget(m_categoryFilterWidget);
 
     QCheckBox *trackerLabel = new QCheckBox(tr("Trackers"), this);
     trackerLabel->setChecked(pref->getTrackerFilterState());
     trackerLabel->setFont(font);
     frameLayout->addWidget(trackerLabel);
 
-    trackerFilters = new TrackerFiltersList(this, transferList);
-    frameLayout->addWidget(trackerFilters);
+    m_trackerFilters = new TrackerFiltersList(this, transferList);
+    frameLayout->addWidget(m_trackerFilters);
 
     connect(statusLabel, SIGNAL(toggled(bool)), statusFilters, SLOT(toggleFilter(bool)));
     connect(statusLabel, SIGNAL(toggled(bool)), pref, SLOT(setStatusFilterState(const bool)));
-    connect(categoryLabel, SIGNAL(toggled(bool)), categoryFilters, SLOT(toggleFilter(bool)));
-    connect(categoryLabel, SIGNAL(toggled(bool)), pref, SLOT(setCategoryFilterState(const bool)));
-    connect(trackerLabel, SIGNAL(toggled(bool)), trackerFilters, SLOT(toggleFilter(bool)));
+    connect(trackerLabel, SIGNAL(toggled(bool)), m_trackerFilters, SLOT(toggleFilter(bool)));
     connect(trackerLabel, SIGNAL(toggled(bool)), pref, SLOT(setTrackerFilterState(const bool)));
-    connect(this, SIGNAL(trackerSuccess(const QString &, const QString &)), trackerFilters, SLOT(trackerSuccess(const QString &, const QString &)));
-    connect(this, SIGNAL(trackerError(const QString &, const QString &)), trackerFilters, SLOT(trackerError(const QString &, const QString &)));
-    connect(this, SIGNAL(trackerWarning(const QString &, const QString &)), trackerFilters, SLOT(trackerWarning(const QString &, const QString &)));
+    connect(this, SIGNAL(trackerSuccess(const QString &, const QString &)), m_trackerFilters, SLOT(trackerSuccess(const QString &, const QString &)));
+    connect(this, SIGNAL(trackerError(const QString &, const QString &)), m_trackerFilters, SLOT(trackerError(const QString &, const QString &)));
+    connect(this, SIGNAL(trackerWarning(const QString &, const QString &)), m_trackerFilters, SLOT(trackerWarning(const QString &, const QString &)));
 }
 
 void TransferListFiltersWidget::setDownloadTrackerFavicon(bool value)
 {
-    trackerFilters->setDownloadTrackerFavicon(value);
+    m_trackerFilters->setDownloadTrackerFavicon(value);
 }
 
 void TransferListFiltersWidget::addTrackers(BitTorrent::TorrentHandle *const torrent, const QList<BitTorrent::TrackerEntry> &trackers)
 {
     foreach (const BitTorrent::TrackerEntry &tracker, trackers)
-        trackerFilters->addItem(tracker.url(), torrent->hash());
+        m_trackerFilters->addItem(tracker.url(), torrent->hash());
 }
 
 void TransferListFiltersWidget::removeTrackers(BitTorrent::TorrentHandle *const torrent, const QList<BitTorrent::TrackerEntry> &trackers)
 {
     foreach (const BitTorrent::TrackerEntry &tracker, trackers)
-        trackerFilters->removeItem(tracker.url(), torrent->hash());
+        m_trackerFilters->removeItem(tracker.url(), torrent->hash());
 }
 
 void TransferListFiltersWidget::changeTrackerless(BitTorrent::TorrentHandle *const torrent, bool trackerless)
 {
-    trackerFilters->changeTrackerless(trackerless, torrent->hash());
+    m_trackerFilters->changeTrackerless(trackerless, torrent->hash());
 }
 
 void TransferListFiltersWidget::trackerSuccess(BitTorrent::TorrentHandle *const torrent, const QString &tracker)
@@ -886,3 +636,9 @@ void TransferListFiltersWidget::trackerError(BitTorrent::TorrentHandle *const to
 {
     emit trackerError(torrent->hash(), tracker);
 }
+
+void TransferListFiltersWidget::onCategoryFilterStateChanged(bool enabled)
+{
+    m_categoryFilterWidget->setVisible(enabled);
+    m_transferList->applyCategoryFilter(enabled ? m_categoryFilterWidget->currentCategory() : QString());
+}
diff --git a/src/gui/transferlistfilterswidget.h b/src/gui/transferlistfilterswidget.h
index 3ea54260a..8f1638673 100644
--- a/src/gui/transferlistfilterswidget.h
+++ b/src/gui/transferlistfilterswidget.h
@@ -90,40 +90,6 @@ private:
     virtual void torrentAboutToBeDeleted(BitTorrent::TorrentHandle *const);
 };
 
-class CategoryFiltersList: public FiltersBase
-{
-    Q_OBJECT
-
-public:
-    CategoryFiltersList(QWidget *parent, TransferListWidget *transferList);
-
-private slots:
-    // Redefine addItem() to make sure the list stays sorted
-    void addItem(const QString &category, bool hasTorrent = false);
-    void removeItem(const QString &category);
-    void removeSelectedCategory();
-    void removeUnusedCategories();
-    void torrentCategoryChanged(BitTorrent::TorrentHandle *const torrent, const QString &oldCategory);
-    void categoryRemoved(const QString &category);
-    void subcategoriesSupportChanged();
-
-private:
-    // These 4 methods are virtual slots in the base class.
-    // No need to redeclare them here as slots.
-    virtual void showMenu(QPoint);
-    virtual void applyFilter(int row);
-    virtual void handleNewTorrent(BitTorrent::TorrentHandle *const torrent);
-    virtual void torrentAboutToBeDeleted(BitTorrent::TorrentHandle *const torrent);
-    QString categoryFromRow(int row) const;
-    int rowFromCategory(const QString &category) const;
-    void refresh();
-
-private:
-    QHash<QString, int> m_categories;
-    int m_totalTorrents;
-    int m_totalCategorized;
-};
-
 class TrackerFiltersList: public FiltersBase
 {
     Q_OBJECT
@@ -169,6 +135,8 @@ private:
     bool m_downloadTrackerFavicon;
 };
 
+class CategoryFilterWidget;
+
 class TransferListFiltersWidget: public QFrame
 {
     Q_OBJECT
@@ -190,8 +158,13 @@ signals:
     void trackerError(const QString &hash, const QString &tracker);
     void trackerWarning(const QString &hash, const QString &tracker);
 
+private slots:
+    void onCategoryFilterStateChanged(bool enabled);
+
 private:
-    TrackerFiltersList *trackerFilters;
+    TransferListWidget *m_transferList;
+    TrackerFiltersList *m_trackerFilters;
+    CategoryFilterWidget *m_categoryFilterWidget;
 };
 
 #endif // TRANSFERLISTFILTERSWIDGET_H
diff --git a/src/src.pro b/src/src.pro
index fe3bd2a5a..8c516a599 100644
--- a/src/src.pro
+++ b/src/src.pro
@@ -7,6 +7,8 @@ CONFIG += c++11
 DEFINES += BOOST_NO_CXX11_RVALUE_REFERENCES
 greaterThan(QT_MAJOR_VERSION, 4): greaterThan(QT_MINOR_VERSION, 1): DEFINES += QBT_USES_QT5
 
+lessThan(QT_MAJOR_VERSION, 5): DEFINES += QStringLiteral=QLatin1String
+
 # Windows specific configuration
 win32: include(../winconf.pri)