Import gtk2 platform theme from qtbase 5.6

Some people still want to use GTK+ 2.x integration which has been
removed from qtbase, so we will ship it in this repository.

The changes compared to qtbase 5.6 branch are:

* Using pkgconfig to link against gtk+-2.0.
* QPlatformTheme::StyleNames hint suggests the gtk2 style.
* QGtk2Dialog::show(): add missing null-check to avoid warnings
  (cherry-picked from 2e2b32a9ab459f66 in qtbase 5.7 branch).

This can be used by exporting QT_QPA_PLATFORMTHEME=gtk2.

Change-Id: I8b5e424d304f146fae72545b98b0ba4cbcf1e6a6
Reviewed-by: J-P Nurmi <jpnurmi@qt.io>

9 files changed, 1025 insertions, 1 deletions

diff --git a/src/plugins/platformthemes/gtk2/gtk2.json b/src/plugins/platformthemes/gtk2/gtk2.json
new file mode 100644
index 0000000..86dd8e5
--- /dev/null
+++ b/src/plugins/platformthemes/gtk2/gtk2.json
@@ -0,0 +1,3 @@
+{
+    "Keys": [ "gtk2" ]
+}
diff --git a/src/plugins/platformthemes/gtk2/gtk2.pro b/src/plugins/platformthemes/gtk2/gtk2.pro
new file mode 100644
index 0000000..296bbf8
--- /dev/null
+++ b/src/plugins/platformthemes/gtk2/gtk2.pro
@@ -0,0 +1,21 @@
+TARGET = qgtk2
+
+QT += core-private gui-private platformsupport-private
+
+CONFIG += X11
+CONFIG += link_pkgconfig
+PKGCONFIG += gtk+-2.0
+
+HEADERS += \
+        qgtk2dialoghelpers.h \
+        qgtk2theme.h
+
+SOURCES += \
+        main.cpp \
+        qgtk2dialoghelpers.cpp \
+        qgtk2theme.cpp \
+
+PLUGIN_TYPE = platformthemes
+PLUGIN_EXTENDS = -
+PLUGIN_CLASS_NAME = QGtk2ThemePlugin
+load(qt_plugin)
diff --git a/src/plugins/platformthemes/gtk2/main.cpp b/src/plugins/platformthemes/gtk2/main.cpp
new file mode 100644
index 0000000..34ac3ff
--- /dev/null
+++ b/src/plugins/platformthemes/gtk2/main.cpp
@@ -0,0 +1,59 @@
+/****************************************************************************
+**
+** Copyright (C) 2015 The Qt Company Ltd.
+** Contact: http://www.qt.io/licensing/
+**
+** This file is part of the plugins of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL21$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see http://www.qt.io/terms-conditions. For further
+** information use the contact form at http://www.qt.io/contact-us.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 2.1 or version 3 as published by the Free
+** Software Foundation and appearing in the file LICENSE.LGPLv21 and
+** LICENSE.LGPLv3 included in the packaging of this file. Please review the
+** following information to ensure the GNU Lesser General Public License
+** requirements will be met: https://www.gnu.org/licenses/lgpl.html and
+** http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
+**
+** As a special exception, The Qt Company gives you certain additional
+** rights. These rights are described in The Qt Company LGPL Exception
+** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#include <qpa/qplatformthemeplugin.h>
+#include "qgtk2theme.h"
+
+QT_BEGIN_NAMESPACE
+
+class QGtk2ThemePlugin : public QPlatformThemePlugin
+{
+   Q_OBJECT
+   Q_PLUGIN_METADATA(IID QPlatformThemeFactoryInterface_iid FILE "gtk2.json")
+
+public:
+    QPlatformTheme *create(const QString &key, const QStringList &params) Q_DECL_OVERRIDE;
+};
+
+QPlatformTheme *QGtk2ThemePlugin::create(const QString &key, const QStringList &params)
+{
+    Q_UNUSED(params);
+    if (!key.compare(QLatin1String(QGtk2Theme::name), Qt::CaseInsensitive))
+        return new QGtk2Theme;
+
+    return 0;
+}
+
+QT_END_NAMESPACE
+
+#include "main.moc"
diff --git a/src/plugins/platformthemes/gtk2/qgtk2dialoghelpers.cpp b/src/plugins/platformthemes/gtk2/qgtk2dialoghelpers.cpp
new file mode 100644
index 0000000..62e5dd2
--- /dev/null
+++ b/src/plugins/platformthemes/gtk2/qgtk2dialoghelpers.cpp
@@ -0,0 +1,624 @@
+/****************************************************************************
+**
+** Copyright (C) 2015 The Qt Company Ltd.
+** Contact: http://www.qt.io/licensing/
+**
+** This file is part of the plugins of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL21$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see http://www.qt.io/terms-conditions. For further
+** information use the contact form at http://www.qt.io/contact-us.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 2.1 or version 3 as published by the Free
+** Software Foundation and appearing in the file LICENSE.LGPLv21 and
+** LICENSE.LGPLv3 included in the packaging of this file. Please review the
+** following information to ensure the GNU Lesser General Public License
+** requirements will be met: https://www.gnu.org/licenses/lgpl.html and
+** http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
+**
+** As a special exception, The Qt Company gives you certain additional
+** rights. These rights are described in The Qt Company LGPL Exception
+** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#include "qgtk2dialoghelpers.h"
+
+#include <qeventloop.h>
+#include <qwindow.h>
+#include <qcolor.h>
+#include <qdebug.h>
+#include <qfont.h>
+
+#include <private/qguiapplication_p.h>
+#include <qpa/qplatformfontdatabase.h>
+
+#undef signals
+#include <gtk/gtk.h>
+#include <gdk/gdk.h>
+#include <gdk/gdkx.h>
+#include <pango/pango.h>
+
+QT_BEGIN_NAMESPACE
+
+class QGtk2Dialog : public QWindow
+{
+    Q_OBJECT
+
+public:
+    QGtk2Dialog(GtkWidget *gtkWidget);
+    ~QGtk2Dialog();
+
+    GtkDialog *gtkDialog() const;
+
+    void exec();
+    bool show(Qt::WindowFlags flags, Qt::WindowModality modality, QWindow *parent);
+    void hide();
+
+Q_SIGNALS:
+    void accept();
+    void reject();
+
+protected:
+    static void onResponse(QGtk2Dialog *dialog, int response);
+
+private slots:
+    void onParentWindowDestroyed();
+
+private:
+    GtkWidget *gtkWidget;
+};
+
+QGtk2Dialog::QGtk2Dialog(GtkWidget *gtkWidget) : gtkWidget(gtkWidget)
+{
+    g_signal_connect_swapped(G_OBJECT(gtkWidget), "response", G_CALLBACK(onResponse), this);
+    g_signal_connect(G_OBJECT(gtkWidget), "delete-event", G_CALLBACK(gtk_widget_hide_on_delete), NULL);
+}
+
+QGtk2Dialog::~QGtk2Dialog()
+{
+    gtk_clipboard_store(gtk_clipboard_get(GDK_SELECTION_CLIPBOARD));
+    gtk_widget_destroy(gtkWidget);
+}
+
+GtkDialog *QGtk2Dialog::gtkDialog() const
+{
+    return GTK_DIALOG(gtkWidget);
+}
+
+void QGtk2Dialog::exec()
+{
+    if (modality() == Qt::ApplicationModal) {
+        // block input to the whole app, including other GTK dialogs
+        gtk_dialog_run(gtkDialog());
+    } else {
+        // block input to the window, allow input to other GTK dialogs
+        QEventLoop loop;
+        connect(this, SIGNAL(accept()), &loop, SLOT(quit()));
+        connect(this, SIGNAL(reject()), &loop, SLOT(quit()));
+        loop.exec();
+    }
+}
+
+bool QGtk2Dialog::show(Qt::WindowFlags flags, Qt::WindowModality modality, QWindow *parent)
+{
+    if (parent) {
+        connect(parent, &QWindow::destroyed, this, &QGtk2Dialog::onParentWindowDestroyed,
+                Qt::UniqueConnection);
+    }
+    setParent(parent);
+    setFlags(flags);
+    setModality(modality);
+
+    gtk_widget_realize(gtkWidget); // creates X window
+
+    if (parent) {
+        XSetTransientForHint(gdk_x11_drawable_get_xdisplay(gtkWidget->window),
+                             gdk_x11_drawable_get_xid(gtkWidget->window),
+                             parent->winId());
+    }
+
+    if (modality != Qt::NonModal) {
+        gdk_window_set_modal_hint(gtkWidget->window, true);
+        QGuiApplicationPrivate::showModalWindow(this);
+    }
+
+    gtk_widget_show(gtkWidget);
+    gdk_window_focus(gtkWidget->window, 0);
+    return true;
+}
+
+void QGtk2Dialog::hide()
+{
+    QGuiApplicationPrivate::hideModalWindow(this);
+    gtk_widget_hide(gtkWidget);
+}
+
+void QGtk2Dialog::onResponse(QGtk2Dialog *dialog, int response)
+{
+    if (response == GTK_RESPONSE_OK)
+        emit dialog->accept();
+    else
+        emit dialog->reject();
+}
+
+void QGtk2Dialog::onParentWindowDestroyed()
+{
+    // The QGtk2*DialogHelper classes own this object. Make sure the parent doesn't delete it.
+    setParent(0);
+}
+
+QGtk2ColorDialogHelper::QGtk2ColorDialogHelper()
+{
+    d.reset(new QGtk2Dialog(gtk_color_selection_dialog_new("")));
+    connect(d.data(), SIGNAL(accept()), this, SLOT(onAccepted()));
+    connect(d.data(), SIGNAL(reject()), this, SIGNAL(reject()));
+
+    GtkWidget *gtkColorSelection = gtk_color_selection_dialog_get_color_selection(GTK_COLOR_SELECTION_DIALOG(d->gtkDialog()));
+    g_signal_connect_swapped(gtkColorSelection, "color-changed", G_CALLBACK(onColorChanged), this);
+}
+
+QGtk2ColorDialogHelper::~QGtk2ColorDialogHelper()
+{
+}
+
+bool QGtk2ColorDialogHelper::show(Qt::WindowFlags flags, Qt::WindowModality modality, QWindow *parent)
+{
+    applyOptions();
+    return d->show(flags, modality, parent);
+}
+
+void QGtk2ColorDialogHelper::exec()
+{
+    d->exec();
+}
+
+void QGtk2ColorDialogHelper::hide()
+{
+    d->hide();
+}
+
+void QGtk2ColorDialogHelper::setCurrentColor(const QColor &color)
+{
+    GtkDialog *gtkDialog = d->gtkDialog();
+    GtkWidget *gtkColorSelection = gtk_color_selection_dialog_get_color_selection(GTK_COLOR_SELECTION_DIALOG(gtkDialog));
+    GdkColor gdkColor;
+    gdkColor.red = color.red() << 8;
+    gdkColor.green = color.green() << 8;
+    gdkColor.blue = color.blue() << 8;
+    gtk_color_selection_set_current_color(GTK_COLOR_SELECTION(gtkColorSelection), &gdkColor);
+    if (color.alpha() < 255) {
+        gtk_color_selection_set_has_opacity_control(GTK_COLOR_SELECTION(gtkColorSelection), true);
+        gtk_color_selection_set_current_alpha(GTK_COLOR_SELECTION(gtkColorSelection), color.alpha() << 8);
+    }
+}
+
+QColor QGtk2ColorDialogHelper::currentColor() const
+{
+    GtkDialog *gtkDialog = d->gtkDialog();
+    GtkWidget *gtkColorSelection = gtk_color_selection_dialog_get_color_selection(GTK_COLOR_SELECTION_DIALOG(gtkDialog));
+    GdkColor gdkColor;
+    gtk_color_selection_get_current_color(GTK_COLOR_SELECTION(gtkColorSelection), &gdkColor);
+    guint16 alpha = gtk_color_selection_get_current_alpha(GTK_COLOR_SELECTION(gtkColorSelection));
+    return QColor(gdkColor.red >> 8, gdkColor.green >> 8, gdkColor.blue >> 8, alpha >> 8);
+}
+
+void QGtk2ColorDialogHelper::onAccepted()
+{
+    emit accept();
+    emit colorSelected(currentColor());
+}
+
+void QGtk2ColorDialogHelper::onColorChanged(QGtk2ColorDialogHelper *dialog)
+{
+    emit dialog->currentColorChanged(dialog->currentColor());
+}
+
+void QGtk2ColorDialogHelper::applyOptions()
+{
+    GtkDialog *gtkDialog = d->gtkDialog();
+    gtk_window_set_title(GTK_WINDOW(gtkDialog), options()->windowTitle().toUtf8());
+
+    GtkWidget *gtkColorSelection = gtk_color_selection_dialog_get_color_selection(GTK_COLOR_SELECTION_DIALOG(gtkDialog));
+    gtk_color_selection_set_has_opacity_control(GTK_COLOR_SELECTION(gtkColorSelection), options()->testOption(QColorDialogOptions::ShowAlphaChannel));
+
+    GtkWidget *okButton = 0;
+    GtkWidget *cancelButton = 0;
+    GtkWidget *helpButton = 0;
+    g_object_get(G_OBJECT(gtkDialog), "ok-button", &okButton, "cancel-button", &cancelButton, "help-button", &helpButton, NULL);
+    if (okButton)
+        g_object_set(G_OBJECT(okButton), "visible", !options()->testOption(QColorDialogOptions::NoButtons), NULL);
+    if (cancelButton)
+        g_object_set(G_OBJECT(cancelButton), "visible", !options()->testOption(QColorDialogOptions::NoButtons), NULL);
+    if (helpButton)
+        gtk_widget_hide(helpButton);
+}
+
+QGtk2FileDialogHelper::QGtk2FileDialogHelper()
+{
+    d.reset(new QGtk2Dialog(gtk_file_chooser_dialog_new("", 0,
+                                                        GTK_FILE_CHOOSER_ACTION_OPEN,
+                                                        GTK_STOCK_CANCEL, GTK_RESPONSE_CANCEL,
+                                                        GTK_STOCK_OK, GTK_RESPONSE_OK, NULL)));
+    connect(d.data(), SIGNAL(accept()), this, SLOT(onAccepted()));
+    connect(d.data(), SIGNAL(reject()), this, SIGNAL(reject()));
+
+    g_signal_connect(GTK_FILE_CHOOSER(d->gtkDialog()), "selection-changed", G_CALLBACK(onSelectionChanged), this);
+    g_signal_connect_swapped(GTK_FILE_CHOOSER(d->gtkDialog()), "current-folder-changed", G_CALLBACK(onCurrentFolderChanged), this);
+}
+
+QGtk2FileDialogHelper::~QGtk2FileDialogHelper()
+{
+}
+
+bool QGtk2FileDialogHelper::show(Qt::WindowFlags flags, Qt::WindowModality modality, QWindow *parent)
+{
+    _dir.clear();
+    _selection.clear();
+
+    applyOptions();
+    return d->show(flags, modality, parent);
+}
+
+void QGtk2FileDialogHelper::exec()
+{
+    d->exec();
+}
+
+void QGtk2FileDialogHelper::hide()
+{
+    // After GtkFileChooserDialog has been hidden, gtk_file_chooser_get_current_folder()
+    // & gtk_file_chooser_get_filenames() will return bogus values -> cache the actual
+    // values before hiding the dialog
+    _dir = directory();
+    _selection = selectedFiles();
+
+    d->hide();
+}
+
+bool QGtk2FileDialogHelper::defaultNameFilterDisables() const
+{
+    return false;
+}
+
+void QGtk2FileDialogHelper::setDirectory(const QUrl &directory)
+{
+    GtkDialog *gtkDialog = d->gtkDialog();
+    gtk_file_chooser_set_current_folder(GTK_FILE_CHOOSER(gtkDialog), directory.toLocalFile().toUtf8());
+}
+
+QUrl QGtk2FileDialogHelper::directory() const
+{
+    // While GtkFileChooserDialog is hidden, gtk_file_chooser_get_current_folder()
+    // returns a bogus value -> return the cached value before hiding
+    if (!_dir.isEmpty())
+        return _dir;
+
+    QString ret;
+    GtkDialog *gtkDialog = d->gtkDialog();
+    gchar *folder = gtk_file_chooser_get_current_folder(GTK_FILE_CHOOSER(gtkDialog));
+    if (folder) {
+        ret = QString::fromUtf8(folder);
+        g_free(folder);
+    }
+    return QUrl::fromLocalFile(ret);
+}
+
+void QGtk2FileDialogHelper::selectFile(const QUrl &filename)
+{
+    GtkDialog *gtkDialog = d->gtkDialog();
+    if (options()->acceptMode() == QFileDialogOptions::AcceptSave) {
+        QFileInfo fi(filename.toLocalFile());
+        gtk_file_chooser_set_current_folder(GTK_FILE_CHOOSER(gtkDialog), fi.path().toUtf8());
+        gtk_file_chooser_set_current_name(GTK_FILE_CHOOSER(gtkDialog), fi.fileName().toUtf8());
+    } else {
+        gtk_file_chooser_select_filename(GTK_FILE_CHOOSER(gtkDialog), filename.toLocalFile().toUtf8());
+    }
+}
+
+QList<QUrl> QGtk2FileDialogHelper::selectedFiles() const
+{
+    // While GtkFileChooserDialog is hidden, gtk_file_chooser_get_filenames()
+    // returns a bogus value -> return the cached value before hiding
+    if (!_selection.isEmpty())
+        return _selection;
+
+    QList<QUrl> selection;
+    GtkDialog *gtkDialog = d->gtkDialog();
+    GSList *filenames = gtk_file_chooser_get_filenames(GTK_FILE_CHOOSER(gtkDialog));
+    for (GSList *it  = filenames; it; it = it->next)
+        selection += QUrl::fromLocalFile(QString::fromUtf8((const char*)it->data));
+    g_slist_free(filenames);
+    return selection;
+}
+
+void QGtk2FileDialogHelper::setFilter()
+{
+    applyOptions();
+}
+
+void QGtk2FileDialogHelper::selectNameFilter(const QString &filter)
+{
+    GtkFileFilter *gtkFilter = _filters.value(filter);
+    if (gtkFilter) {
+        GtkDialog *gtkDialog = d->gtkDialog();
+        gtk_file_chooser_set_filter(GTK_FILE_CHOOSER(gtkDialog), gtkFilter);
+    }
+}
+
+QString QGtk2FileDialogHelper::selectedNameFilter() const
+{
+    GtkDialog *gtkDialog = d->gtkDialog();
+    GtkFileFilter *gtkFilter = gtk_file_chooser_get_filter(GTK_FILE_CHOOSER(gtkDialog));
+    return _filterNames.value(gtkFilter);
+}
+
+void QGtk2FileDialogHelper::onAccepted()
+{
+    emit accept();
+
+    QString filter = selectedNameFilter();
+    if (filter.isEmpty())
+        emit filterSelected(filter);
+
+    QList<QUrl> files = selectedFiles();
+    emit filesSelected(files);
+    if (files.count() == 1)
+        emit fileSelected(files.first());
+}
+
+void QGtk2FileDialogHelper::onSelectionChanged(GtkDialog *gtkDialog, QGtk2FileDialogHelper *helper)
+{
+    QString selection;
+    gchar *filename = gtk_file_chooser_get_filename(GTK_FILE_CHOOSER(gtkDialog));
+    if (filename) {
+        selection = QString::fromUtf8(filename);
+        g_free(filename);
+    }
+    emit helper->currentChanged(QUrl::fromLocalFile(selection));
+}
+
+void QGtk2FileDialogHelper::onCurrentFolderChanged(QGtk2FileDialogHelper *dialog)
+{
+    emit dialog->directoryEntered(dialog->directory());
+}
+
+static GtkFileChooserAction gtkFileChooserAction(const QSharedPointer<QFileDialogOptions> &options)
+{
+    switch (options->fileMode()) {
+    case QFileDialogOptions::AnyFile:
+    case QFileDialogOptions::ExistingFile:
+    case QFileDialogOptions::ExistingFiles:
+        if (options->acceptMode() == QFileDialogOptions::AcceptOpen)
+            return GTK_FILE_CHOOSER_ACTION_OPEN;
+        else
+            return GTK_FILE_CHOOSER_ACTION_SAVE;
+    case QFileDialogOptions::Directory:
+    case QFileDialogOptions::DirectoryOnly:
+    default:
+        if (options->acceptMode() == QFileDialogOptions::AcceptOpen)
+            return GTK_FILE_CHOOSER_ACTION_SELECT_FOLDER;
+        else
+            return GTK_FILE_CHOOSER_ACTION_CREATE_FOLDER;
+    }
+}
+
+void QGtk2FileDialogHelper::applyOptions()
+{
+    GtkDialog *gtkDialog = d->gtkDialog();
+    const QSharedPointer<QFileDialogOptions> &opts = options();
+
+    gtk_window_set_title(GTK_WINDOW(gtkDialog), opts->windowTitle().toUtf8());
+    gtk_file_chooser_set_local_only(GTK_FILE_CHOOSER(gtkDialog), true);
+
+    const GtkFileChooserAction action = gtkFileChooserAction(opts);
+    gtk_file_chooser_set_action(GTK_FILE_CHOOSER(gtkDialog), action);
+
+    const bool selectMultiple = opts->fileMode() == QFileDialogOptions::ExistingFiles;
+    gtk_file_chooser_set_select_multiple(GTK_FILE_CHOOSER(gtkDialog), selectMultiple);
+
+    const bool confirmOverwrite = !opts->testOption(QFileDialogOptions::DontConfirmOverwrite);
+    gtk_file_chooser_set_do_overwrite_confirmation(GTK_FILE_CHOOSER(gtkDialog), confirmOverwrite);
+
+    const QStringList nameFilters = opts->nameFilters();
+    if (!nameFilters.isEmpty())
+        setNameFilters(nameFilters);
+
+    if (opts->initialDirectory().isLocalFile())
+        setDirectory(opts->initialDirectory());
+
+    foreach (const QUrl &filename, opts->initiallySelectedFiles())
+        selectFile(filename);
+
+    const QString initialNameFilter = opts->initiallySelectedNameFilter();
+    if (!initialNameFilter.isEmpty())
+        selectNameFilter(initialNameFilter);
+
+#if GTK_CHECK_VERSION(2, 20, 0)
+    GtkWidget *acceptButton = gtk_dialog_get_widget_for_response(gtkDialog, GTK_RESPONSE_OK);
+    if (acceptButton) {
+        if (opts->isLabelExplicitlySet(QFileDialogOptions::Accept))
+            gtk_button_set_label(GTK_BUTTON(acceptButton), opts->labelText(QFileDialogOptions::Accept).toUtf8());
+        else if (opts->acceptMode() == QFileDialogOptions::AcceptOpen)
+            gtk_button_set_label(GTK_BUTTON(acceptButton), GTK_STOCK_OPEN);
+        else
+            gtk_button_set_label(GTK_BUTTON(acceptButton), GTK_STOCK_SAVE);
+    }
+
+    GtkWidget *rejectButton = gtk_dialog_get_widget_for_response(gtkDialog, GTK_RESPONSE_CANCEL);
+    if (rejectButton) {
+        if (opts->isLabelExplicitlySet(QFileDialogOptions::Reject))
+            gtk_button_set_label(GTK_BUTTON(rejectButton), opts->labelText(QFileDialogOptions::Reject).toUtf8());
+        else
+            gtk_button_set_label(GTK_BUTTON(rejectButton), GTK_STOCK_CANCEL);
+    }
+#endif
+}
+
+void QGtk2FileDialogHelper::setNameFilters(const QStringList &filters)
+{
+    GtkDialog *gtkDialog = d->gtkDialog();
+    foreach (GtkFileFilter *filter, _filters)
+        gtk_file_chooser_remove_filter(GTK_FILE_CHOOSER(gtkDialog), filter);
+
+    _filters.clear();
+    _filterNames.clear();
+
+    foreach (const QString &filter, filters) {
+        GtkFileFilter *gtkFilter = gtk_file_filter_new();
+        const QString name = filter.left(filter.indexOf(QLatin1Char('(')));
+        const QStringList extensions = cleanFilterList(filter);
+
+        gtk_file_filter_set_name(gtkFilter, name.isEmpty() ? extensions.join(QStringLiteral(", ")).toUtf8() : name.toUtf8());
+        foreach (const QString &ext, extensions)
+            gtk_file_filter_add_pattern(gtkFilter, ext.toUtf8());
+
+        gtk_file_chooser_add_filter(GTK_FILE_CHOOSER(gtkDialog), gtkFilter);
+
+        _filters.insert(filter, gtkFilter);
+        _filterNames.insert(gtkFilter, filter);
+    }
+}
+
+QGtk2FontDialogHelper::QGtk2FontDialogHelper()
+{
+    d.reset(new QGtk2Dialog(gtk_font_selection_dialog_new("")));
+    connect(d.data(), SIGNAL(accept()), this, SLOT(onAccepted()));
+    connect(d.data(), SIGNAL(reject()), this, SIGNAL(reject()));
+}
+
+QGtk2FontDialogHelper::~QGtk2FontDialogHelper()
+{
+}
+
+bool QGtk2FontDialogHelper::show(Qt::WindowFlags flags, Qt::WindowModality modality, QWindow *parent)
+{
+    applyOptions();
+    return d->show(flags, modality, parent);
+}
+
+void QGtk2FontDialogHelper::exec()
+{
+    d->exec();
+}
+
+void QGtk2FontDialogHelper::hide()
+{
+    d->hide();
+}
+
+static QString qt_fontToString(const QFont &font)
+{
+    PangoFontDescription *desc = pango_font_description_new();
+    pango_font_description_set_size(desc, (font.pointSizeF() > 0.0 ? font.pointSizeF() : QFontInfo(font).pointSizeF()) * PANGO_SCALE);
+    pango_font_description_set_family(desc, QFontInfo(font).family().toUtf8());
+
+    int weight = font.weight();
+    if (weight >= QFont::Black)
+        pango_font_description_set_weight(desc, PANGO_WEIGHT_HEAVY);
+    else if (weight >= QFont::ExtraBold)
+        pango_font_description_set_weight(desc, PANGO_WEIGHT_ULTRABOLD);
+    else if (weight >= QFont::Bold)
+        pango_font_description_set_weight(desc, PANGO_WEIGHT_BOLD);
+    else if (weight >= QFont::DemiBold)
+        pango_font_description_set_weight(desc, PANGO_WEIGHT_SEMIBOLD);
+    else if (weight >= QFont::Medium)
+        pango_font_description_set_weight(desc, PANGO_WEIGHT_MEDIUM);
+    else if (weight >= QFont::Normal)
+        pango_font_description_set_weight(desc, PANGO_WEIGHT_NORMAL);
+    else if (weight >= QFont::Light)
+        pango_font_description_set_weight(desc, PANGO_WEIGHT_LIGHT);
+    else if (weight >= QFont::ExtraLight)
+        pango_font_description_set_weight(desc, PANGO_WEIGHT_ULTRALIGHT);
+    else
+        pango_font_description_set_weight(desc, PANGO_WEIGHT_THIN);
+
+    int style = font.style();
+    if (style == QFont::StyleItalic)
+        pango_font_description_set_style(desc, PANGO_STYLE_ITALIC);
+    else if (style == QFont::StyleOblique)
+        pango_font_description_set_style(desc, PANGO_STYLE_OBLIQUE);
+    else
+        pango_font_description_set_style(desc, PANGO_STYLE_NORMAL);
+
+    char *str = pango_font_description_to_string(desc);
+    QString name = QString::fromUtf8(str);
+    pango_font_description_free(desc);
+    g_free(str);
+    return name;
+}
+
+static QFont qt_fontFromString(const QString &name)
+{
+    QFont font;
+    PangoFontDescription *desc = pango_font_description_from_string(name.toUtf8());
+    font.setPointSizeF(static_cast<float>(pango_font_description_get_size(desc)) / PANGO_SCALE);
+
+    QString family = QString::fromUtf8(pango_font_description_get_family(desc));
+    if (!family.isEmpty())
+        font.setFamily(family);
+
+    const int weight = pango_font_description_get_weight(desc);
+    font.setWeight(QPlatformFontDatabase::weightFromInteger(weight));
+
+    PangoStyle style = pango_font_description_get_style(desc);
+    if (style == PANGO_STYLE_ITALIC)
+        font.setStyle(QFont::StyleItalic);
+    else if (style == PANGO_STYLE_OBLIQUE)
+        font.setStyle(QFont::StyleOblique);
+    else
+        font.setStyle(QFont::StyleNormal);
+
+    pango_font_description_free(desc);
+    return font;
+}
+
+void QGtk2FontDialogHelper::setCurrentFont(const QFont &font)
+{
+    GtkFontSelectionDialog *gtkDialog = GTK_FONT_SELECTION_DIALOG(d->gtkDialog());
+    gtk_font_selection_dialog_set_font_name(gtkDialog, qt_fontToString(font).toUtf8());
+}
+
+QFont QGtk2FontDialogHelper::currentFont() const
+{
+    GtkFontSelectionDialog *gtkDialog = GTK_FONT_SELECTION_DIALOG(d->gtkDialog());
+    gchar *name = gtk_font_selection_dialog_get_font_name(gtkDialog);
+    QFont font = qt_fontFromString(QString::fromUtf8(name));
+    g_free(name);
+    return font;
+}
+
+void QGtk2FontDialogHelper::onAccepted()
+{
+    emit currentFontChanged(currentFont());
+    emit accept();
+    emit fontSelected(currentFont());
+}
+
+void QGtk2FontDialogHelper::applyOptions()
+{
+    GtkDialog *gtkDialog = d->gtkDialog();
+    const QSharedPointer<QFontDialogOptions> &opts = options();
+
+    gtk_window_set_title(GTK_WINDOW(gtkDialog), opts->windowTitle().toUtf8());
+
+    GtkWidget *okButton = gtk_font_selection_dialog_get_ok_button(GTK_FONT_SELECTION_DIALOG(gtkDialog));
+    GtkWidget *cancelButton = gtk_font_selection_dialog_get_cancel_button(GTK_FONT_SELECTION_DIALOG(gtkDialog));
+    if (okButton)
+        gtk_widget_set_visible(okButton, !options()->testOption(QFontDialogOptions::NoButtons));
+    if (cancelButton)
+        gtk_widget_set_visible(cancelButton, !options()->testOption(QFontDialogOptions::NoButtons));
+}
+
+QT_END_NAMESPACE
+
+#include "qgtk2dialoghelpers.moc"
diff --git a/src/plugins/platformthemes/gtk2/qgtk2dialoghelpers.h b/src/plugins/platformthemes/gtk2/qgtk2dialoghelpers.h
new file mode 100644
index 0000000..1410566
--- /dev/null
+++ b/src/plugins/platformthemes/gtk2/qgtk2dialoghelpers.h
@@ -0,0 +1,140 @@
+/****************************************************************************
+**
+** Copyright (C) 2015 The Qt Company Ltd.
+** Contact: http://www.qt.io/licensing/
+**
+** This file is part of the plugins of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL21$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see http://www.qt.io/terms-conditions. For further
+** information use the contact form at http://www.qt.io/contact-us.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 2.1 or version 3 as published by the Free
+** Software Foundation and appearing in the file LICENSE.LGPLv21 and
+** LICENSE.LGPLv3 included in the packaging of this file. Please review the
+** following information to ensure the GNU Lesser General Public License
+** requirements will be met: https://www.gnu.org/licenses/lgpl.html and
+** http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
+**
+** As a special exception, The Qt Company gives you certain additional
+** rights. These rights are described in The Qt Company LGPL Exception
+** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#ifndef QGTK2DIALOGHELPERS_P_H
+#define QGTK2DIALOGHELPERS_P_H
+
+#include <QtCore/qhash.h>
+#include <QtCore/qlist.h>
+#include <QtCore/qurl.h>
+#include <QtCore/qscopedpointer.h>
+#include <QtCore/qstring.h>
+#include <qpa/qplatformdialoghelper.h>
+
+typedef struct _GtkDialog GtkDialog;
+typedef struct _GtkFileFilter GtkFileFilter;
+
+QT_BEGIN_NAMESPACE
+
+class QGtk2Dialog;
+class QColor;
+
+class QGtk2ColorDialogHelper : public QPlatformColorDialogHelper
+{
+    Q_OBJECT
+
+public:
+    QGtk2ColorDialogHelper();
+    ~QGtk2ColorDialogHelper();
+
+    bool show(Qt::WindowFlags flags, Qt::WindowModality modality, QWindow *parent) Q_DECL_OVERRIDE;
+    void exec() Q_DECL_OVERRIDE;
+    void hide() Q_DECL_OVERRIDE;
+
+    void setCurrentColor(const QColor &color) Q_DECL_OVERRIDE;
+    QColor currentColor() const Q_DECL_OVERRIDE;
+
+private Q_SLOTS:
+    void onAccepted();
+
+private:
+    static void onColorChanged(QGtk2ColorDialogHelper *helper);
+    void applyOptions();
+
+    QScopedPointer<QGtk2Dialog> d;
+};
+
+class QGtk2FileDialogHelper : public QPlatformFileDialogHelper
+{
+    Q_OBJECT
+
+public:
+    QGtk2FileDialogHelper();
+    ~QGtk2FileDialogHelper();
+
+    bool show(Qt::WindowFlags flags, Qt::WindowModality modality, QWindow *parent) Q_DECL_OVERRIDE;
+    void exec() Q_DECL_OVERRIDE;
+    void hide() Q_DECL_OVERRIDE;
+
+    bool defaultNameFilterDisables() const Q_DECL_OVERRIDE;
+    void setDirectory(const QUrl &directory) Q_DECL_OVERRIDE;
+    QUrl directory() const Q_DECL_OVERRIDE;
+    void selectFile(const QUrl &filename) Q_DECL_OVERRIDE;
+    QList<QUrl> selectedFiles() const Q_DECL_OVERRIDE;
+    void setFilter() Q_DECL_OVERRIDE;
+    void selectNameFilter(const QString &filter) Q_DECL_OVERRIDE;
+    QString selectedNameFilter() const Q_DECL_OVERRIDE;
+
+private Q_SLOTS:
+    void onAccepted();
+
+private:
+    static void onSelectionChanged(GtkDialog *dialog, QGtk2FileDialogHelper *helper);
+    static void onCurrentFolderChanged(QGtk2FileDialogHelper *helper);
+    void applyOptions();
+    void setNameFilters(const QStringList &filters);
+
+    QUrl _dir;
+    QList<QUrl> _selection;
+    QHash<QString, GtkFileFilter*> _filters;
+    QHash<GtkFileFilter*, QString> _filterNames;
+    QScopedPointer<QGtk2Dialog> d;
+};
+
+class QGtk2FontDialogHelper : public QPlatformFontDialogHelper
+{
+    Q_OBJECT
+
+public:
+    QGtk2FontDialogHelper();
+    ~QGtk2FontDialogHelper();
+
+    bool show(Qt::WindowFlags flags, Qt::WindowModality modality, QWindow *parent) Q_DECL_OVERRIDE;
+    void exec() Q_DECL_OVERRIDE;
+    void hide() Q_DECL_OVERRIDE;
+
+    void setCurrentFont(const QFont &font) Q_DECL_OVERRIDE;
+    QFont currentFont() const Q_DECL_OVERRIDE;
+
+private Q_SLOTS:
+    void onAccepted();
+
+private:
+    void applyOptions();
+
+    QScopedPointer<QGtk2Dialog> d;
+};
+
+QT_END_NAMESPACE
+
+#endif // QGTK2DIALOGHELPERS_P_H
diff --git a/src/plugins/platformthemes/gtk2/qgtk2theme.cpp b/src/plugins/platformthemes/gtk2/qgtk2theme.cpp
new file mode 100644
index 0000000..c8c7ce5
--- /dev/null
+++ b/src/plugins/platformthemes/gtk2/qgtk2theme.cpp
@@ -0,0 +1,118 @@
+/****************************************************************************
+**
+** Copyright (C) 2015 The Qt Company Ltd.
+** Contact: http://www.qt.io/licensing/
+**
+** This file is part of the plugins of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL21$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see http://www.qt.io/terms-conditions. For further
+** information use the contact form at http://www.qt.io/contact-us.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 2.1 or version 3 as published by the Free
+** Software Foundation and appearing in the file LICENSE.LGPLv21 and
+** LICENSE.LGPLv3 included in the packaging of this file. Please review the
+** following information to ensure the GNU Lesser General Public License
+** requirements will be met: https://www.gnu.org/licenses/lgpl.html and
+** http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
+**
+** As a special exception, The Qt Company gives you certain additional
+** rights. These rights are described in The Qt Company LGPL Exception
+** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#include "qgtk2theme.h"
+#include "qgtk2dialoghelpers.h"
+#include <QVariant>
+
+#undef signals
+#include <gtk/gtk.h>
+
+#include <X11/Xlib.h>
+
+QT_BEGIN_NAMESPACE
+
+const char *QGtk2Theme::name = "gtk2";
+
+static QString gtkSetting(const gchar *propertyName)
+{
+    GtkSettings *settings = gtk_settings_get_default();
+    gchararray value;
+    g_object_get(settings, propertyName, &value, NULL);
+    QString str = QString::fromUtf8(value);
+    g_free(value);
+    return str;
+}
+
+QGtk2Theme::QGtk2Theme()
+{
+    // gtk_init will reset the Xlib error handler, and that causes
+    // Qt applications to quit on X errors. Therefore, we need to manually restore it.
+    int (*oldErrorHandler)(Display *, XErrorEvent *) = XSetErrorHandler(NULL);
+
+    gtk_init(0, 0);
+
+    XSetErrorHandler(oldErrorHandler);
+}
+
+QVariant QGtk2Theme::themeHint(QPlatformTheme::ThemeHint hint) const
+{
+    switch (hint) {
+    case QPlatformTheme::SystemIconThemeName:
+        return QVariant(gtkSetting("gtk-icon-theme-name"));
+    case QPlatformTheme::SystemIconFallbackThemeName:
+        return QVariant(gtkSetting("gtk-fallback-icon-theme"));
+    case QPlatformTheme::StyleNames:
+        return QVariant(QStringList(QStringLiteral("gtk2")));
+    default:
+        return QGnomeTheme::themeHint(hint);
+    }
+}
+
+QString QGtk2Theme::gtkFontName() const
+{
+    QString cfgFontName = gtkSetting("gtk-font-name");
+    if (!cfgFontName.isEmpty())
+        return cfgFontName;
+    return QGnomeTheme::gtkFontName();
+}
+
+bool QGtk2Theme::usePlatformNativeDialog(DialogType type) const
+{
+    switch (type) {
+    case ColorDialog:
+        return true;
+    case FileDialog:
+        return true;
+    case FontDialog:
+        return true;
+    default:
+        return false;
+    }
+}
+
+QPlatformDialogHelper *QGtk2Theme::createPlatformDialogHelper(DialogType type) const
+{
+    switch (type) {
+    case ColorDialog:
+        return new QGtk2ColorDialogHelper;
+    case FileDialog:
+        return new QGtk2FileDialogHelper;
+    case FontDialog:
+        return new QGtk2FontDialogHelper;
+    default:
+        return 0;
+    }
+}
+
+QT_END_NAMESPACE
diff --git a/src/plugins/platformthemes/gtk2/qgtk2theme.h b/src/plugins/platformthemes/gtk2/qgtk2theme.h
new file mode 100644
index 0000000..8798fed
--- /dev/null
+++ b/src/plugins/platformthemes/gtk2/qgtk2theme.h
@@ -0,0 +1,57 @@
+/****************************************************************************
+**
+** Copyright (C) 2015 The Qt Company Ltd.
+** Contact: http://www.qt.io/licensing/
+**
+** This file is part of the plugins of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL21$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see http://www.qt.io/terms-conditions. For further
+** information use the contact form at http://www.qt.io/contact-us.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 2.1 or version 3 as published by the Free
+** Software Foundation and appearing in the file LICENSE.LGPLv21 and
+** LICENSE.LGPLv3 included in the packaging of this file. Please review the
+** following information to ensure the GNU Lesser General Public License
+** requirements will be met: https://www.gnu.org/licenses/lgpl.html and
+** http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
+**
+** As a special exception, The Qt Company gives you certain additional
+** rights. These rights are described in The Qt Company LGPL Exception
+** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#ifndef QGTK2THEME_H
+#define QGTK2THEME_H
+
+#include <private/qgenericunixthemes_p.h>
+
+QT_BEGIN_NAMESPACE
+
+class QGtk2Theme : public QGnomeTheme
+{
+public:
+    QGtk2Theme();
+
+    virtual QVariant themeHint(ThemeHint hint) const Q_DECL_OVERRIDE;
+    virtual QString gtkFontName() const Q_DECL_OVERRIDE;
+
+    bool usePlatformNativeDialog(DialogType type) const Q_DECL_OVERRIDE;
+    QPlatformDialogHelper *createPlatformDialogHelper(DialogType type) const Q_DECL_OVERRIDE;
+
+    static const char *name;
+};
+
+QT_END_NAMESPACE
+
+#endif // QGTK2THEME_H
diff --git a/src/plugins/platformthemes/platformthemes.pro b/src/plugins/platformthemes/platformthemes.pro
new file mode 100644
index 0000000..064880e
--- /dev/null
+++ b/src/plugins/platformthemes/platformthemes.pro
@@ -0,0 +1,2 @@
+TEMPLATE = subdirs
+SUBDIRS = gtk2
diff --git a/src/plugins/plugins.pro b/src/plugins/plugins.pro
index 38e0c33..8afe610 100644
--- a/src/plugins/plugins.pro
+++ b/src/plugins/plugins.pro
@@ -1,2 +1,2 @@
 TEMPLATE = subdirs
-SUBDIRS = styles
+SUBDIRS = platformthemes styles