Related to #5175, remove the unused MapEvent listeners from the layer…

… classes. Since all layers are stored in the map root node now, the layer information is automatically discarded along with the host node.

radiant/layers/LayerManager.cpp

@@ -490,13 +490,4 @@ int LayerManager::getLowestUnusedLayerID()
 	return -1;
 }
 
-void LayerManager::onMapEvent(IMap::MapEvent ev)
-{
-	if (ev == IMap::MapUnloaded || ev == IMap::MapLoading)
-	{ 
-		// Purge layer info before map is loading or after it has been unloaded
-		reset();
-	}
-}
-
 } // namespace scene

radiant/layers/LayerManager.h

@@ -119,8 +119,6 @@ class LayerManager :
 	sigc::signal<void> signal_nodeMembershipChanged() override;
 
 private:
-	void onMapEvent(IMap::MapEvent ev);
-
 	// Internal event emitter
 	void onLayersChanged();
 

radiant/layers/LayerModule.cpp

@@ -4,6 +4,7 @@
 #include "icommandsystem.h"
 #include "itextstream.h"
 #include "imapinfofile.h"
+#include "imap.h"
 
 #include "modulesystem/StaticModule.h"
 #include "LayerManager.h"
@@ -113,10 +114,6 @@ class LayerModule :
 			{ cmd::ARGTYPE_STRING | cmd::ARGTYPE_OPTIONAL });
 		GlobalEventManager().addCommand("CreateNewLayer", "CreateNewLayer");
 
-		GlobalMapModule().signal_mapEvent().connect(
-			sigc::mem_fun(*this, &LayerModule::onMapEvent)
-		);
-
 		GlobalMapInfoFileManager().registerInfoFileModule(
 			std::make_shared<LayerInfoFileModule>()
 		);
@@ -128,11 +125,6 @@ class LayerModule :
 	}
 
 private:
-	void onMapEvent(IMap::MapEvent ev)
-	{
-		// TODO
-	}
-
 	// Command target
 	void createLayerCmd(const cmd::ArgumentList& args)
 	{