add a DBus slot to get an XDG activation token

Will check if the passed shellSessionId is the current one for safety.
Will try to generate a token and pass it back.

Allows e.g. Kate to properly activate existing instance windows

CCBUG: 442265

src/session/Session.cpp

@@ -34,12 +34,19 @@
 #include <KNotification>
 #include <KProcess>
 #include <KSelectAction>
+#include <KWindowSystem>
 
 #ifndef Q_OS_WIN
 #include <KPtyDevice>
 #endif
 #include <KShell>
 
+// wayland window activation
+#define HAVE_WAYLAND __has_include(<KWaylandExtras>)
+#if HAVE_WAYLAND
+#include <KWaylandExtras>
+#endif
+
 // Konsole
 #if HAVE_DBUS
 #include <sessionadaptor.h>
@@ -2161,4 +2168,49 @@ void Session::runCommandFromLayout(const QString &command) const
     _emulation->sendText(command + QLatin1Char('\n'));
 }
 
+QString Session::activationToken(const QString &shellSessionIdForRequest) const
+{
+    // safety check, only work if the caller knows our id
+    // they will read it from the SHELL_SESSION_ID env var inside this session
+    if (shellSessionIdForRequest != shellSessionId()) {
+        return {};
+    }
+
+#if HAVE_DBUS && HAVE_WAYLAND
+    // no window active, no token
+    // same if we don't run wayland
+    const auto window = qApp->activeWindow();
+    if (!window || !window->window() || !KWindowSystem::isPlatformWayland()) {
+        return {};
+    }
+
+    // we will respond delayed, as the token needs to arrive
+    Q_ASSERT(calledFromDBus());
+    const auto msg = message();
+    setDelayedReply(true);
+
+    // we need to filter the response with the request serial
+    const int launchedSerial = KWaylandExtras::self()->lastInputSerial(window->window()->windowHandle());
+    connect(
+        KWaylandExtras::self(),
+        &KWaylandExtras::xdgActivationTokenArrived,
+        this,
+        [msg, launchedSerial](int tokenSerial, QString token) {
+            // if wrong token, ignore it, but we must always reply to not stall the caller
+            // we use here a SingleShotConnection, we will just be called once!
+            if (tokenSerial != launchedSerial) {
+                token.clear();
+            }
+            auto reply = msg.createReply(token);
+            QDBusConnection::sessionBus().send(reply);
+        },
+        Qt::SingleShotConnection);
+
+    KWaylandExtras::requestXdgActivationToken(window->window()->windowHandle(), launchedSerial, {});
+
+#endif
+
+    return {};
+}
+
 #include "moc_Session.cpp"

src/session/Session.h

@@ -9,6 +9,8 @@
 #ifndef SESSION_H
 #define SESSION_H
 
+#include "config-konsole.h"
+
 // Qt
 #include <QHash>
 #include <QLoggingCategory>
@@ -19,6 +21,10 @@
 #include <QUuid>
 #include <QWidget>
 
+#if HAVE_DBUS
+#include <QDBusContext>
+#endif
+
 // Konsole
 #include "Shortcut_p.h"
 #include "config-konsole.h"
@@ -51,7 +57,11 @@ class SessionController;
  * or send input to the program in the terminal in the form of keypresses and mouse
  * activity.
  */
+#if HAVE_DBUS
+class KONSOLEPRIVATE_EXPORT Session : public QObject, protected QDBusContext
+#else
 class KONSOLEPRIVATE_EXPORT Session : public QObject
+#endif
 {
     Q_OBJECT
     Q_CLASSINFO("D-Bus Interface", "org.kde.konsole.Session")
@@ -728,6 +738,14 @@ public Q_SLOTS:
      */
     Q_SCRIPTABLE QStringList getDisplayedTextList(int startLineOffset, int endLineOffset);
 
+    /**
+     * DBus slot to get an XDG activation token.
+     * Will check if the passed shellSessionId is the current one for safety.
+     * Will try to generate a token and pass it back.
+     * Can only be called from DBus, will answer delayed.
+     */
+    Q_SCRIPTABLE QString activationToken(const QString &shellSessionIdForRequest) const;
+
 Q_SIGNALS:
 
     /** Emitted when the terminal process starts. */