feat(slock): implement ext_session_lock_v1 backend

note: did not run lints or fully test yet

src/wayland/session_lock/lock.hpp

@@ -0,0 +1,38 @@
+#pragma once
+
+#include <qobject.h>
+#include <qtclasshelpermacros.h>
+#include <qwayland-ext-session-lock-v1.h>
+
+class QSWaylandSessionLockManager;
+
+class QSWaylandSessionLock
+    : public QObject
+    , public QtWayland::ext_session_lock_v1 {
+	Q_OBJECT;
+
+public:
+	QSWaylandSessionLock(QSWaylandSessionLockManager* manager, ::ext_session_lock_v1* lock);
+	~QSWaylandSessionLock() override;
+	Q_DISABLE_COPY_MOVE(QSWaylandSessionLock);
+
+	void unlock();
+
+	// Returns true if the lock has not finished.
+	[[nodiscard]] bool active() const;
+	// Returns true if the compositor considers the session to be locked.
+	[[nodiscard]] bool hasCompositorLock() const;
+
+signals:
+	void compositorLocked();
+	void unlocked();
+
+private:
+	void ext_session_lock_v1_locked() override;
+	void ext_session_lock_v1_finished() override;
+
+	QSWaylandSessionLockManager* manager; // static and not dealloc'd
+
+	// true when the compositor determines the session is locked
+	bool locked = false;
+};