Disable window rule configuration for Wayland

Summary:
The window rule detection is too bound to X11 for it to work for
Wayland windows. In fact it results in the config module just crashing.
Thus it's better to just disable the items in the menu. As it's only for
X11 windows we can also enforce platform xcb for the rules dialog.

Test Plan: Menu disabled on Wayland window, menu enabled on Xwayland window

Reviewers: #kwin, #plasma

Subscribers: plasma-devel, kwin

Tags: #plasma

Differential Revision: https://phabricator.kde.org/D10594

kcmkwin/kwinrules/main.cpp

@@ -248,6 +248,7 @@ static int edit(Window wid, bool whole_app)
 extern "C"
 KWIN_EXPORT int kdemain(int argc, char* argv[])
 {
+    qputenv("QT_QPA_PLATFORM", "xcb");
     QApplication app(argc, argv);
     app.setApplicationDisplayName(i18n("KWin"));
     app.setApplicationName("kwin_rules_dialog");

useractions.cpp

@@ -40,6 +40,7 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
 #include "effects.h"
 #include "platform.h"
 #include "screens.h"
+#include "shell_client.h"
 #include "virtualdesktops.h"
 #include "scripting/scripting.h"
 
@@ -318,10 +319,12 @@ void UserActionsMenu::init()
     QAction *action = advancedMenu->addAction(i18n("Special &Window Settings..."));
     action->setIcon(QIcon::fromTheme(QStringLiteral("preferences-system-windows-actions")));
     action->setData(Options::WindowRulesOp);
+    m_rulesOperation = action;
 
     action = advancedMenu->addAction(i18n("S&pecial Application Settings..."));
     action->setIcon(QIcon::fromTheme(QStringLiteral("preferences-system-windows-actions")));
     action->setData(Options::ApplicationRulesOp);
+    m_applicationRulesOperation = action;
     if (!kwinApp()->config()->isImmutable() &&
             !KAuthorized::authorizeControlModules(configModules(true)).isEmpty()) {
         advancedMenu->addSeparator();
@@ -465,6 +468,15 @@ void UserActionsMenu::menuAboutToShow()
         action->setText(i18n("&Extensions"));
     }
 
+    // disable rules for Wayland windows - dialog is X11 only
+    if (qobject_cast<ShellClient*>(m_client.data())) {
+        m_rulesOperation->setEnabled(false);
+        m_applicationRulesOperation->setEnabled(false);
+    } else {
+        m_rulesOperation->setEnabled(true);
+        m_applicationRulesOperation->setEnabled(true);
+    }
+
     showHideActivityMenu();
 }
 

useractions.h

@@ -260,6 +260,8 @@ private:
      * The Client for which the menu is shown.
      **/
     QWeakPointer<AbstractClient> m_client;
+    QAction *m_rulesOperation = nullptr;
+    QAction *m_applicationRulesOperation = nullptr;
 };
 
 class ShortcutDialog