Support multiple desktop names in XDG_CURRENT_DESKTOP

According to the Desktop Entry Specification, “If $XDG_CURRENT_DESKTOP is
set then it contains a colon-separated list of strings”. For example, on
GNOME Flashback session that variable is set to “GNOME-Flashback:GNOME”.

The value returned by QGenericUnixServices::desktopEnvironment() is in
most cases the uppercase variant of $XDG_CURRENT_DESKTOP variable.

In qgenericunixthemes.cpp, we need to support multiple names in the
return result of that function. If at least one part is in the list of
Gtk+-based desktop environments, then we should use gtk2 platform theme.

Change-Id: I0c9de68756d41b031e822be8cf100ca5c0b202ae
Reviewed-by: David Faure <david.faure@kdab.com>
Reviewed-by: Friedemann Kleint <Friedemann.Kleint@theqtcompany.com>

1 files changed, 17 insertions, 12 deletions

diff --git a/src/platformsupport/themes/genericunix/qgenericunixthemes.cpp b/src/platformsupport/themes/genericunix/qgenericunixthemes.cpp
index a28fbd62f4..1060ff283b 100644
--- a/src/platformsupport/themes/genericunix/qgenericunixthemes.cpp
+++ b/src/platformsupport/themes/genericunix/qgenericunixthemes.cpp
@@ -637,20 +637,25 @@ QStringList QGenericUnixTheme::themeNames()
     QStringList result;
     if (QGuiApplication::desktopSettingsAware()) {
         const QByteArray desktopEnvironment = QGuiApplicationPrivate::platformIntegration()->services()->desktopEnvironment();
-        if (desktopEnvironment == "KDE") {
+        QList<QByteArray> gtkBasedEnvironments;
+        gtkBasedEnvironments << "GNOME"
+                             << "X-CINNAMON"
+                             << "UNITY"
+                             << "MATE"
+                             << "XFCE"
+                             << "LXDE";
+        QList<QByteArray> desktopNames = desktopEnvironment.split(':');
+        Q_FOREACH (const QByteArray &desktopName, desktopNames) {
+            if (desktopEnvironment == "KDE") {
 #ifndef QT_NO_SETTINGS
-            result.push_back(QLatin1String(QKdeTheme::name));
+                result.push_back(QLatin1String(QKdeTheme::name));
 #endif
-        } else if (desktopEnvironment == "GNOME" ||
-                desktopEnvironment == "X-CINNAMON" ||
-                desktopEnvironment == "UNITY" ||
-                desktopEnvironment == "MATE" ||
-                desktopEnvironment == "XFCE" ||
-                desktopEnvironment == "LXDE") { // Gtk-based desktops
-            // prefer the GTK2 theme implementation with native dialogs etc.
-            result.push_back(QStringLiteral("gtk2"));
-            // fallback to the generic Gnome theme if loading the GTK2 theme fails
-            result.push_back(QLatin1String(QGnomeTheme::name));
+            } else if (gtkBasedEnvironments.contains(desktopName)) {
+                // prefer the GTK2 theme implementation with native dialogs etc.
+                result.push_back(QStringLiteral("gtk2"));
+                // fallback to the generic Gnome theme if loading the GTK2 theme fails
+                result.push_back(QLatin1String(QGnomeTheme::name));
+            }
         }
         const QString session = QString::fromLocal8Bit(qgetenv("DESKTOP_SESSION"));
         if (!session.isEmpty() && session != QLatin1String("default") && !result.contains(session))