xcb: set _KDE_NET_WM_DESKTOP_FILE and _GTK_APPLICATION_ID for window

in top level, which are in used very common for KDE and GNOME.

Pick-to: 6.5 6.2
Fixes: QTBUG-117488
Change-Id: I88fe7b4afe44e4ac8f07e60e990cbe68498e98d9
Reviewed-by: Nicolas Fella <nicolas.fella@kdab.com>
Reviewed-by: Ilya Fedin <fedin-ilja2010@ya.ru>
Reviewed-by: Axel Spoerl <axel.spoerl@qt.io>
(cherry picked from commit 70d3c15e8e9ef5965a242022e6681dd87dff5bd4)
Reviewed-by: Qt Cherry-pick Bot <cherrypick_bot@qt-project.org>

src/plugins/platforms/xcb/qxcbatom.cpp

@@ -111,6 +111,7 @@ static const char *xcb_atomnames = {
     "_NET_WM_WINDOW_TYPE_NORMAL\0"
     "_KDE_NET_WM_WINDOW_TYPE_OVERRIDE\0"
 
+    "_KDE_NET_WM_DESKTOP_FILE\0"
     "_KDE_NET_WM_FRAME_STRUT\0"
     "_NET_FRAME_EXTENTS\0"
 
@@ -196,6 +197,7 @@ static const char *xcb_atomnames = {
     "_COMPIZ_DECOR_REQUEST\0"
     "_COMPIZ_DECOR_DELETE_PIXMAP\0"
     "_COMPIZ_TOOLKIT_ACTION\0"
+    "_GTK_APPLICATION_ID\0"
     "_GTK_LOAD_ICONTHEMES\0"
     "AT_SPI_BUS\0"
     "EDID\0"

src/plugins/platforms/xcb/qxcbatom.h

@@ -112,6 +112,7 @@ public:
         Atom_NET_WM_WINDOW_TYPE_NORMAL,
         Atom_KDE_NET_WM_WINDOW_TYPE_OVERRIDE,
 
+        Atom_KDE_NET_WM_DESKTOP_FILE,
         Atom_KDE_NET_WM_FRAME_STRUT,
         Atom_NET_FRAME_EXTENTS,
 
@@ -199,6 +200,7 @@ public:
         Atom_COMPIZ_DECOR_REQUEST,
         Atom_COMPIZ_DECOR_DELETE_PIXMAP,
         Atom_COMPIZ_TOOLKIT_ACTION,
+        Atom_GTK_APPLICATION_ID,
         Atom_GTK_LOAD_ICONTHEMES,
 
         AtomAT_SPI_BUS,

src/plugins/platforms/xcb/qxcbwindow.cpp

@@ -6,6 +6,7 @@
 #include <QtDebug>
 #include <QMetaEnum>
 #include <QScreen>
+#include <QtCore/QFileInfo>
 #include <QtGui/QIcon>
 #include <QtGui/QRegion>
 #include <QtGui/private/qhighdpiscaling_p.h>
@@ -388,6 +389,31 @@ void QXcbWindow::create()
                             XCB_ATOM_STRING, 8, wmClass.size(), wmClass.constData());
     }
 
+    QString desktopFileName = QGuiApplication::desktopFileName();
+    if (QGuiApplication::desktopFileName().isEmpty()) {
+        QFileInfo fi = QFileInfo(QCoreApplication::instance()->applicationFilePath());
+        QStringList domainName =
+                QCoreApplication::instance()->organizationDomain().split(QLatin1Char('.'),
+                                                                         Qt::SkipEmptyParts);
+
+        if (domainName.isEmpty()) {
+            desktopFileName = fi.baseName();
+        } else {
+            for (int i = 0; i < domainName.size(); ++i)
+                desktopFileName.prepend(QLatin1Char('.')).prepend(domainName.at(i));
+            desktopFileName.append(fi.baseName());
+        }
+    }
+    if (!desktopFileName.isEmpty()) {
+        const QByteArray dfName = desktopFileName.toUtf8();
+        xcb_change_property(xcb_connection(), XCB_PROP_MODE_REPLACE,
+                            m_window, atom(QXcbAtom::Atom_KDE_NET_WM_DESKTOP_FILE),
+                            atom(QXcbAtom::AtomUTF8_STRING), 8, dfName.size(), dfName.constData());
+        xcb_change_property(xcb_connection(), XCB_PROP_MODE_REPLACE,
+                            m_window, atom(QXcbAtom::Atom_GTK_APPLICATION_ID),
+                            atom(QXcbAtom::AtomUTF8_STRING), 8, dfName.size(), dfName.constData());
+    }
+
     if (connection()->hasXSync()) {
         m_syncCounter = xcb_generate_id(xcb_connection());
         xcb_sync_create_counter(xcb_connection(), m_syncCounter, m_syncValue);