Add request attaching a layer surface as toplevel parent

src/qwaylandlayershellintegration.cpp

@@ -12,12 +12,15 @@
 #include <QtWaylandClient/private/qwaylanddisplay_p.h>
 #include <QtWaylandClient/private/qwaylandwindow_p.h>
 
+#include <QPlatformSurfaceEvent>
+
 namespace LayerShellQt
 {
 QWaylandLayerShellIntegration::QWaylandLayerShellIntegration()
     : QWaylandShellIntegrationTemplate<QWaylandLayerShellIntegration>(5)
     , m_xdgActivation(new QWaylandXdgActivationV1)
 {
+    qGuiApp->installEventFilter(this);
 }
 
 QWaylandLayerShellIntegration::~QWaylandLayerShellIntegration()
@@ -32,4 +35,29 @@ QtWaylandClient::QWaylandShellSurface *QWaylandLayerShellIntegration::createShel
     return new QWaylandLayerSurface(this, window);
 }
 
+bool QWaylandLayerShellIntegration::eventFilter(QObject *watched, QEvent *event)
+{
+    if (event->type() == QEvent::PlatformSurface && static_cast<QPlatformSurfaceEvent *>(event)->surfaceEventType() == QPlatformSurfaceEvent::SurfaceCreated) {
+        QWindow *window = qobject_cast<QWindow *>(watched);
+        if (!window) {
+            return false;
+        }
+        auto child = static_cast<QtWaylandClient::QWaylandWindow *>(window->handle());
+        auto maybeSetParent = [child]() {
+            auto transientParent = child->window()->transientParent();
+            if (!transientParent) {
+                return;
+            }
+            if (auto layerParent = qobject_cast<QWaylandLayerSurface *>(static_cast<QtWaylandClient::QWaylandWindow *>(transientParent->handle())->shellSurface())) {
+                if (auto topevel = child->surfaceRole<xdg_toplevel>()) {
+                    layerParent->set_parent_of(topevel);
+                }
+            }
+        };
+        maybeSetParent();
+        connect(window, &QWindow::transientParentChanged, child, maybeSetParent);
+        connect(child, &QtWaylandClient::QWaylandWindow::surfaceRoleCreated, this, maybeSetParent);
+    }
+    return false;
+}
 }

src/qwaylandlayershellintegration_p.h

@@ -32,6 +32,7 @@ public:
     QtWaylandClient::QWaylandShellSurface *createShellSurface(QtWaylandClient::QWaylandWindow *window) override;
 
 private:
+    bool eventFilter(QObject *watched, QEvent *event) override;
     QScopedPointer<QWaylandXdgActivationV1> m_xdgActivation;
 };
 

src/wlr-layer-shell-unstable-v1.xml

@@ -403,5 +403,11 @@
       </description>
       <arg name="edge" type="uint"/>
     </request>
+
+    <request name="set_parent_of">
+      <description summary="assign this layer_surface as an xdg_toplevel parent">
+      </description>
+      <arg name="toplevel" type="object" interface="xdg_toplevel" />
+    </request>
   </interface>
 </protocol>