Import DConf-based QSettings backend prototype

Change-Id: Ic18f82e1da5fb8de33d0eaae51b40e97bf1ab8a4
Reviewed-by: J-P Nurmi <jpnurmi@digia.com>

3 files changed, 357 insertions, 0 deletions

diff --git a/backend/backend.pri b/backend/backend.pri
new file mode 100644
index 0000000..70f84d1
--- /dev/null
+++ b/backend/backend.pri
@@ -0,0 +1,11 @@
+INCLUDEPATH += $$PWD/dconf
+DEPENDPATH += $$PWD/dconf
+
+CONFIG += no_keywords link_pkgconfig
+PKGCONFIG += dconf
+
+SOURCES += \
+    $$PWD/dconf/dconfsettings.cpp
+
+HEADERS  += \
+    $$PWD/dconf/dconfsettings.h
diff --git a/backend/dconf/dconfsettings.cpp b/backend/dconf/dconfsettings.cpp
new file mode 100644
index 0000000..63ecce2
--- /dev/null
+++ b/backend/dconf/dconfsettings.cpp
@@ -0,0 +1,267 @@
+/****************************************************************************
+**
+** Copyright (C) 2013 Digia Plc and/or its subsidiary(-ies).
+** Contact: http://www.qt-project.org/legal
+**
+** This file is prototype code for the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** 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 Digia.  For licensing terms and
+** conditions see http://qt.digia.com/licensing.  For further information
+** use the contact form at http://qt.digia.com/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 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL included in the
+** packaging of this file.  Please review the following information to
+** ensure the GNU Lesser General Public License version 2.1 requirements
+** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
+**
+** In addition, as a special exception, Digia gives you certain additional
+** rights.  These rights are described in the Digia Qt LGPL Exception
+** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 3.0 as published by the Free Software
+** Foundation and appearing in the file LICENSE.GPL included in the
+** packaging of this file.  Please review the following information to
+** ensure the GNU General Public License version 3.0 requirements will be
+** met: http://www.gnu.org/copyleft/gpl.html.
+**
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+#include "dconfsettings.h"
+#include <qvariant.h>
+#include <qdebug.h>
+extern "C" {
+#include <dconf/dconf.h>
+}
+
+DConfSettings::DConfSettings(QObject *parent) : Settings(parent)
+{
+    client = dconf_client_new();
+    g_object_ref(client);
+
+    g_signal_connect(G_OBJECT(client), "changed", G_CALLBACK(changeCallback), this);
+
+    dconf_client_watch_fast(client, "/org/qt-project/"); // TODO
+}
+
+DConfSettings::~DConfSettings()
+{
+    dconf_client_unwatch_fast(client, "/org/qt-project/"); // TODO
+
+    g_object_unref(client);
+}
+
+void DConfSettings::remove(const QString &key)
+{
+    set(key, QVariant());
+}
+
+void DConfSettings::set(const QString &key, const QVariant &value)
+{
+    GVariant *var = toGVariant(value);
+    dconf_client_write_fast(client, key.toUtf8(), var, NULL);
+}
+
+bool DConfSettings::get(const QString &key, QVariant *value) const
+{
+    GVariant *var = dconf_client_read(client, key.toUtf8());
+    if (var) {
+        if (value)
+            *value = toQVariant(var);
+        g_variant_unref(var);
+        return true;
+    }
+    return false;
+}
+
+QStringList DConfSettings::children(const QString &prefix, ChildSpec spec) const
+{
+    QString pfx = prefix;
+    if (!pfx.endsWith(QLatin1Char('/')))
+        pfx.append(QLatin1Char('/'));
+
+    QStringList lst;
+    gint len = 0;
+
+    gchar **arr = dconf_client_list(client, pfx.toUtf8(), &len);
+    for (int i = 0; i < len; ++i) {
+        const QString value = QString::fromUtf8(arr[i]);
+        const QByteArray path = QString(pfx + value).toUtf8();
+        if (spec == AllKeys || (spec == ChildKeys && dconf_is_key(path, NULL)) || (spec == ChildGroups && dconf_is_dir(path, NULL)))
+            lst += value;
+    }
+    g_strfreev(arr);
+    return lst;
+}
+
+void DConfSettings::clear()
+{
+}
+
+void DConfSettings::sync()
+{
+    dconf_client_sync(client);
+}
+
+void DConfSettings::flush()
+{
+    sync();
+}
+
+bool DConfSettings::isWritable() const
+{
+    return dconf_client_is_writable(client, NULL);
+}
+
+QString DConfSettings::fileName() const
+{
+    return QString();
+}
+
+QVariant DConfSettings::toQVariant(GVariant *value)
+{
+    if (!value)
+        return QVariant();
+
+    switch (g_variant_classify(value)) {
+    case G_VARIANT_CLASS_BOOLEAN:
+        return QVariant::fromValue(g_variant_get_boolean(value));
+    case G_VARIANT_CLASS_BYTE:
+        return QVariant::fromValue(g_variant_get_byte(value));
+    case G_VARIANT_CLASS_INT16:
+        return QVariant::fromValue(g_variant_get_int16(value));
+    case G_VARIANT_CLASS_UINT16:
+        return QVariant::fromValue(g_variant_get_uint16(value));
+    case G_VARIANT_CLASS_INT32:
+        return QVariant::fromValue(g_variant_get_int32(value));
+    case G_VARIANT_CLASS_UINT32:
+        return QVariant::fromValue(g_variant_get_uint32(value));
+    case G_VARIANT_CLASS_INT64:
+        return QVariant::fromValue(g_variant_get_int64(value));
+    case G_VARIANT_CLASS_UINT64:
+        return QVariant::fromValue(g_variant_get_uint64(value));
+    case G_VARIANT_CLASS_DOUBLE:
+        return QVariant::fromValue(g_variant_get_double(value));
+    case G_VARIANT_CLASS_STRING:
+    case G_VARIANT_CLASS_OBJECT_PATH:
+    case G_VARIANT_CLASS_SIGNATURE:
+        return QString::fromUtf8(g_variant_get_string(value, NULL));
+    // TODO:
+    case G_VARIANT_CLASS_HANDLE:
+    case G_VARIANT_CLASS_VARIANT:
+    case G_VARIANT_CLASS_MAYBE:
+    case G_VARIANT_CLASS_ARRAY:
+    case G_VARIANT_CLASS_TUPLE:
+    case G_VARIANT_CLASS_DICT_ENTRY:
+    default:
+        return QVariant();
+    }
+}
+
+GVariant* DConfSettings::toGVariant(const QVariant& value)
+{
+    if (!value.isValid())
+        return NULL;
+
+    switch (value.type()) {
+    case QVariant::Invalid:
+        return NULL;
+    case QVariant::Bool:
+        return g_variant_new_boolean(value.toBool());
+    case QVariant::Int:
+        return g_variant_new_int32(value.toInt());
+    case QVariant::UInt:
+        return g_variant_new_uint32(value.toUInt());
+    case QVariant::LongLong:
+        return g_variant_new_int64(value.toLongLong());
+    case QVariant::ULongLong:
+        return g_variant_new_uint64(value.toULongLong());
+    case QVariant::Double:
+        return g_variant_new_double(value.toDouble());
+    case QVariant::Char:
+        return g_variant_new_byte(value.toChar().toLatin1());
+    case QVariant::String:
+        return g_variant_new_string(value.toString().toUtf8());
+    case QVariant::ByteArray:
+        return g_variant_new_bytestring(value.toByteArray());
+    case QVariant::Map:
+    case QVariant::List:
+    case QVariant::StringList:
+    case QVariant::BitArray:
+    case QVariant::Date:
+    case QVariant::Time:
+    case QVariant::DateTime:
+    case QVariant::Url:
+    case QVariant::Locale:
+    case QVariant::Rect:
+    case QVariant::RectF:
+    case QVariant::Size:
+    case QVariant::SizeF:
+    case QVariant::Line:
+    case QVariant::LineF:
+    case QVariant::Point:
+    case QVariant::PointF:
+    case QVariant::RegExp:
+    case QVariant::RegularExpression:
+    case QVariant::Hash:
+    case QVariant::EasingCurve:
+    case QVariant::Uuid:
+    case QVariant::ModelIndex:
+
+    case QVariant::Font:
+    case QVariant::Pixmap:
+    case QVariant::Brush:
+    case QVariant::Color:
+    case QVariant::Palette:
+    case QVariant::Image:
+    case QVariant::Polygon:
+    case QVariant::Region:
+    case QVariant::Bitmap:
+    case QVariant::Cursor:
+    case QVariant::KeySequence:
+    case QVariant::Pen:
+    case QVariant::TextLength:
+    case QVariant::TextFormat:
+    case QVariant::Matrix:
+    case QVariant::Transform:
+    case QVariant::Matrix4x4:
+    case QVariant::Vector2D:
+    case QVariant::Vector3D:
+    case QVariant::Vector4D:
+    case QVariant::Quaternion:
+    case QVariant::PolygonF:
+    case QVariant::Icon:
+
+    case QVariant::SizePolicy:
+
+    default:
+        return NULL;
+    }
+}
+
+void DConfSettings::changeCallback(DConfClient *client, char *prefix, char **changes, char *tag, void *userData)
+{
+    Q_UNUSED(client);
+    Q_UNUSED(tag);
+
+    DConfSettings *settings = static_cast<DConfSettings*>(userData);
+    while (settings && changes && changes[0]) {
+        const QString key = QString::fromUtf8(changes[0]);
+        QVariant value;
+        settings->get(prefix, &value);
+        qDebug() << Q_FUNC_INFO << prefix << key << value;
+        Q_EMIT settings->changed(key, value);
+        ++changes;
+    }
+}
diff --git a/backend/dconf/dconfsettings.h b/backend/dconf/dconfsettings.h
new file mode 100644
index 0000000..1cdfa72
--- /dev/null
+++ b/backend/dconf/dconfsettings.h
@@ -0,0 +1,79 @@
+/****************************************************************************
+**
+** Copyright (C) 2013 Digia Plc and/or its subsidiary(-ies).
+** Contact: http://www.qt-project.org/legal
+**
+** This file is prototype code for the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** 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 Digia.  For licensing terms and
+** conditions see http://qt.digia.com/licensing.  For further information
+** use the contact form at http://qt.digia.com/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 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL included in the
+** packaging of this file.  Please review the following information to
+** ensure the GNU Lesser General Public License version 2.1 requirements
+** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
+**
+** In addition, as a special exception, Digia gives you certain additional
+** rights.  These rights are described in the Digia Qt LGPL Exception
+** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 3.0 as published by the Free Software
+** Foundation and appearing in the file LICENSE.GPL included in the
+** packaging of this file.  Please review the following information to
+** ensure the GNU General Public License version 3.0 requirements will be
+** met: http://www.gnu.org/copyleft/gpl.html.
+**
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+#ifndef DCONFSETTINGS_H
+#define DCONFSETTINGS_H
+
+#include "settings.h"
+
+typedef struct _GVariant GVariant;
+typedef struct _DConfClient DConfClient;
+
+class DConfSettings : public Settings
+{
+    Q_OBJECT
+
+public:
+    explicit DConfSettings(QObject *parent = 0);
+    ~DConfSettings();
+
+    void remove(const QString &key);
+    void set(const QString &key, const QVariant &value);
+    bool get(const QString &key, QVariant *value) const;
+
+    QStringList children(const QString &prefix, ChildSpec spec) const;
+
+    void clear();
+    void sync();
+    void flush();
+    bool isWritable() const;
+    QString fileName() const;
+
+protected:
+    static QVariant toQVariant(GVariant *value);
+    static GVariant *toGVariant(const QVariant& value);
+
+    static void changeCallback(DConfClient *client, char *prefix, char **changes, char *tag, void *userData);
+
+private:
+    DConfClient *client;
+};
+
+#endif // DCONFSETTINGS_H