Add example event listener on player_footstep.

Signed-off-by: aixxe <me@aixxe.net>

src/Events/TestListener.h

@@ -0,0 +1,23 @@
+#pragma once
+
+class TestEventListener: public IGameEventListener2 {
+	public:
+		TestEventListener(const char* name) {
+			// Register self as an event listener.
+			gameevents->AddListener(this, name, false);
+		};
+
+		~TestEventListener() {
+			// Unregister when destructor is called.
+			gameevents->RemoveListener(this);
+		}
+
+		void FireGameEvent(IGameEvent* event) {
+			// Print text to console when event is fired.
+			cvar->ConsoleColorPrintf(Color(150, 255, 150), "Event fired: %s\n", event->GetName());
+		}
+
+		int GetEventDebugID() override {
+			return EVENT_DEBUG_ID_INIT;
+		};
+};