Add brief for input::listener class

src/input/listener.cpp

@@ -33,7 +33,7 @@ listener::~listener()
 	set_event_dispatcher(nullptr);
 }
 
-void listener::set_event_dispatcher(::event_dispatcher* event_dispatcher)
+void listener::set_event_dispatcher(event_dispatcher* event_dispatcher)
 {
 	if (this->event_dispatcher)
 	{

src/input/listener.hpp

@@ -27,6 +27,9 @@
 
 namespace input {
 
+/**
+ * Listens for all types of input events.
+ */
 class listener:
 	public event_handler<key_pressed_event>,
 	public event_handler<mouse_moved_event>,