Add XfceTheme class

app/src/desktopthemes/xfcetheme.cpp

+#include "xfcetheme.h"
+
+#include <QVariantList>
+#include <QDir>
+#include <QProcess>
+#include <QDBusMessage>
+#include <QDBusConnection>
+#include <QDBusVariant>
+#include <QDebug>
+
+XfceTheme::XfceTheme(const QString &path, QObject *parent)
+    : QObject(parent), path_(path)
+{
+    themeName_ = QDir(path_).dirName();
+}
+
+bool XfceTheme::applyAsWallpaper() const
+{
+    return setConfig("xfce4-desktop", "/backdrop/screen0/monitor0/workspace0/last-image", path_);
+}
+
+bool XfceTheme::applyAsIcon() const
+{
+    return setConfig("xsettings", "/Net/IconThemeName", themeName_);
+}
+
+bool XfceTheme::applyAsCursor() const
+{
+    return setConfig("xsettings", "/Gtk/CursorThemeName", themeName_);
+}
+
+bool XfceTheme::applyAsGtk2Theme() const
+{
+    return setConfig("xsettings", "/Net/ThemeName", themeName_);
+}
+
+bool XfceTheme::applyAsXfwm4Theme() const
+{
+    return setConfig("xfwm4", "/general/theme", themeName_);
+}
+
+bool XfceTheme::setConfig(const QString &channel, const QString &property, const QString &value) const
+{
+    auto message = QDBusMessage::createMethodCall("org.xfce.Xfconf", "/org/xfce/Xfconf", "org.xfce.Xfconf", "SetProperty");
+    message.setArguments(QVariantList() << QVariant(channel) << QVariant(property) << QVariant::fromValue(QDBusVariant(value)));
+    auto reply = QDBusConnection::sessionBus().call(message);
+
+    if (reply.type() == QDBusMessage::ErrorMessage) {
+        qWarning() << reply.errorMessage();
+        return false;
+    }
+    return true;
+}

app/src/desktopthemes/xfcetheme.h

+#pragma once
+
+#include <QObject>
+
+class XfceTheme : public QObject
+{
+    Q_OBJECT
+
+public:
+    explicit XfceTheme(const QString &path, QObject *parent = nullptr);
+
+    bool applyAsWallpaper() const;
+    bool applyAsIcon() const;
+    bool applyAsCursor() const;
+    bool applyAsGtk2Theme() const;
+    bool applyAsXfwm4Theme() const;
+
+private:
+    bool setConfig(const QString &channel, const QString &property, const QString &value) const;
+
+    QString path_;
+    QString themeName_;
+};