[wayland] Add support for DpmsInterface

Our server announces the DpmsManagerInterface and in the DRM backend
we announce support for Dpms on the OutputInterface (if the Output
supports it) and we connect to changing Dpms requests.

backends/drm/drm_backend.cpp

@@ -612,6 +612,40 @@ void DrmOutput::cleanupBlackBuffer()
     }
 }
 
+static KWayland::Server::OutputInterface::DpmsMode toWaylandDpmsMode(DrmOutput::DpmsMode mode)
+{
+    using namespace KWayland::Server;
+    switch (mode) {
+    case DrmOutput::DpmsMode::On:
+        return OutputInterface::DpmsMode::On;
+    case DrmOutput::DpmsMode::Standby:
+        return OutputInterface::DpmsMode::Standby;
+    case DrmOutput::DpmsMode::Suspend:
+        return OutputInterface::DpmsMode::Suspend;
+    case DrmOutput::DpmsMode::Off:
+        return OutputInterface::DpmsMode::Off;
+    default:
+        Q_UNREACHABLE();
+    }
+}
+
+static DrmOutput::DpmsMode fromWaylandDpmsMode(KWayland::Server::OutputInterface::DpmsMode wlMode)
+{
+    using namespace KWayland::Server;
+    switch (wlMode) {
+    case OutputInterface::DpmsMode::On:
+        return DrmOutput::DpmsMode::On;
+    case OutputInterface::DpmsMode::Standby:
+        return DrmOutput::DpmsMode::Standby;
+    case OutputInterface::DpmsMode::Suspend:
+        return DrmOutput::DpmsMode::Suspend;
+    case OutputInterface::DpmsMode::Off:
+        return DrmOutput::DpmsMode::Off;
+    default:
+        Q_UNREACHABLE();
+    }
+}
+
 void DrmOutput::init(drmModeConnector *connector)
 {
     initEdid(connector);
@@ -683,6 +717,17 @@ void DrmOutput::init(drmModeConnector *connector)
         m_waylandOutput->addMode(QSize(m->hdisplay, m->vdisplay), flags, refreshRate);
     }
 
+    // set dpms
+    if (!m_dpms.isNull()) {
+        m_waylandOutput->setDpmsSupported(true);
+        m_waylandOutput->setDpmsMode(toWaylandDpmsMode(m_dpmsMode));
+        connect(m_waylandOutput, &KWayland::Server::OutputInterface::dpmsModeRequested, this,
+            [this] (KWayland::Server::OutputInterface::DpmsMode mode) {
+                setDpms(fromWaylandDpmsMode(mode));
+            }, Qt::QueuedConnection
+        );
+    }
+
     m_waylandOutput->create();
 }
 
@@ -909,6 +954,9 @@ void DrmOutput::setDpms(DrmOutput::DpmsMode mode)
         return;
     }
     m_dpmsMode = mode;
+    if (m_waylandOutput) {
+        m_waylandOutput->setDpmsMode(toWaylandDpmsMode(m_dpmsMode));
+    }
     emit dpmsChanged();
     if (m_dpmsMode != DpmsMode::On) {
         connect(input(), &InputRedirection::globalPointerChanged, this, &DrmOutput::reenableDpms);

wayland_server.cpp

@@ -34,6 +34,7 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
 #include <KWayland/Server/compositor_interface.h>
 #include <KWayland/Server/datadevicemanager_interface.h>
 #include <KWayland/Server/display.h>
+#include <KWayland/Server/dpms_interface.h>
 #include <KWayland/Server/idle_interface.h>
 #include <KWayland/Server/output_interface.h>
 #include <KWayland/Server/plasmashell_interface.h>
@@ -63,6 +64,7 @@ WaylandServer::WaylandServer(QObject *parent)
     : QObject(parent)
 {
     qRegisterMetaType<KWayland::Server::SurfaceInterface *>("KWayland::Server::SurfaceInterface *");
+    qRegisterMetaType<KWayland::Server::OutputInterface::DpmsMode>();
 }
 
 WaylandServer::~WaylandServer()
@@ -186,6 +188,8 @@ void WaylandServer::init(const QByteArray &socketName)
     );
     auto shadowManager = m_display->createShadowManager(m_display);
     shadowManager->create();
+
+    m_display->createDpmsManager(m_display)->create();
 }
 
 void WaylandServer::initWorkspace()