From 5cfe9428aa6c8b7828f1506eba82daa8427e2fae Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Martin=20Gr=C3=A4=C3=9Flin?= <mgraesslin@kde.org>
Date: Thu, 17 Dec 2015 15:32:41 +0100
Subject: [PATCH] [backends/wayland] Use server side decorations if available

---
 backends/wayland/wayland_backend.cpp | 14 ++++++++++++++
 1 file changed, 14 insertions(+)

diff --git a/backends/wayland/wayland_backend.cpp b/backends/wayland/wayland_backend.cpp
index 430f630073..5b4dfeee19 100644
--- a/backends/wayland/wayland_backend.cpp
+++ b/backends/wayland/wayland_backend.cpp
@@ -40,6 +40,7 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
 #include <KWayland/Client/region.h>
 #include <KWayland/Client/registry.h>
 #include <KWayland/Client/seat.h>
+#include <KWayland/Client/server_decoration.h>
 #include <KWayland/Client/shell.h>
 #include <KWayland/Client/shm_pool.h>
 #include <KWayland/Client/surface.h>
@@ -424,6 +425,19 @@ void WaylandBackend::createSurface()
         qCCritical(KWIN_WAYLAND_BACKEND) << "Creating Wayland Surface failed";
         return;
     }
+    using namespace KWayland::Client;
+    auto iface = m_registry->interface(Registry::Interface::ServerSideDecorationManager);
+    if (iface.name != 0) {
+        auto manager = m_registry->createServerSideDecorationManager(iface.name, iface.version, this);
+        auto decoration = manager->create(m_surface, this);
+        connect(decoration, &ServerSideDecoration::modeChanged, this,
+            [this, decoration] {
+                if (decoration->mode() != ServerSideDecoration::Mode::Server) {
+                    decoration->requestMode(ServerSideDecoration::Mode::Server);
+                }
+            }
+        );
+    }
     if (m_seat) {
         m_seat->setInstallCursor(true);
     }