Use Null-Propagation Operator

OpenRA.Game/Activities/Activity.cs

@@ -185,8 +185,7 @@ protected virtual void OnActorDispose(Actor self) { }
 		/// </summary>
 		internal void OnActorDisposeOuter(Actor self)
 		{
-			if (ChildActivity != null)
-				ChildActivity.OnActorDisposeOuter(self);
+			ChildActivity?.OnActorDisposeOuter(self);
 
 			OnActorDispose(self);
 		}
@@ -199,8 +198,7 @@ public virtual void Cancel(Actor self, bool keepQueue = false)
 			if (!IsInterruptible)
 				return;
 
-			if (ChildActivity != null)
-				ChildActivity.Cancel(self);
+			ChildActivity?.Cancel(self);
 
 			// Directly mark activities that are queued and therefore didn't run yet as done
 			State = State == ActivityState.Queued ? ActivityState.Done : ActivityState.Canceling;
@@ -243,11 +241,9 @@ protected void PrintActivityTree(Actor self, Activity origin = null, int level =
 
 				Console.WriteLine(GetType().ToString().Split('.').Last());
 
-				if (ChildActivity != null)
-					ChildActivity.PrintActivityTree(self, origin, level + 1);
+				ChildActivity?.PrintActivityTree(self, origin, level + 1);
 
-				if (NextActivity != null)
-					NextActivity.PrintActivityTree(self, origin, level);
+				NextActivity?.PrintActivityTree(self, origin, level);
 			}
 		}
 

OpenRA.Game/Activities/CallFunc.cs

@@ -26,7 +26,7 @@ public CallFunc(Action a, bool interruptible)
 
 		public override bool Tick(Actor self)
 		{
-			if (a != null) a();
+			a?.Invoke();
 			return true;
 		}
 	}

OpenRA.Game/Actor.cs

@@ -329,8 +329,7 @@ public void QueueActivity(Activity nextActivity)
 
 		public void CancelActivity()
 		{
-			if (CurrentActivity != null)
-				CurrentActivity.Cancel(this);
+			CurrentActivity?.Cancel(this);
 		}
 
 		public override int GetHashCode()
@@ -382,8 +381,7 @@ public void Dispose()
 		{
 			// If CurrentActivity isn't null, run OnActorDisposeOuter in case some cleanups are needed.
 			// This should be done before the FrameEndTask to avoid dependency issues.
-			if (CurrentActivity != null)
-				CurrentActivity.OnActorDisposeOuter(this);
+			CurrentActivity?.OnActorDisposeOuter(this);
 
 			// Allow traits/activities to prevent a race condition when they depend on disposing the actor (e.g. Transforms)
 			WillDispose = true;
@@ -402,8 +400,7 @@ public void Dispose()
 				World.TraitDict.RemoveActor(this);
 				Disposed = true;
 
-				if (luaInterface != null)
-					luaInterface.Value.OnActorDestroyed();
+				luaInterface?.Value.OnActorDestroyed();
 			});
 		}
 

OpenRA.Game/Download.cs

@@ -90,8 +90,7 @@ void DisposeWebClient()
 		public void CancelAsync()
 		{
 			lock (syncObject)
-				if (wc != null)
-					wc.CancelAsync();
+				wc?.CancelAsync();
 		}
 	}
 }

OpenRA.Game/FieldLoader.cs

@@ -179,8 +179,7 @@ public static object GetValue(string fieldName, Type fieldType, string value, Me
 
 		public static object GetValue(string fieldName, Type fieldType, MiniYaml yaml, MemberInfo field)
 		{
-			var value = yaml.Value;
-			if (value != null) value = value.Trim();
+			var value = yaml.Value?.Trim();
 
 			if (fieldType == typeof(int))
 			{

OpenRA.Game/FileSystem/FileSystem.cs

@@ -197,10 +197,7 @@ Stream GetFromCache(string filename)
 			var package = fileIndex[filename]
 				.LastOrDefault(x => x.Contains(filename));
 
-			if (package != null)
-				return package.GetStream(filename);
-
-			return null;
+			return package?.GetStream(filename);
 		}
 
 		public Stream Open(string filename)

OpenRA.Game/FileSystem/ZipFile.cs

@@ -66,8 +66,7 @@ public bool Contains(string filename)
 
 			public void Dispose()
 			{
-				if (pkg != null)
-					pkg.Close();
+				pkg?.Close();
 			}
 
 			public IReadOnlyPackage OpenPackage(string filename, FileSystem context)

OpenRA.Game/Game.cs

@@ -80,7 +80,7 @@ static string TimestampedFilename(bool includemilliseconds = false)
 
 		static void JoinInner(OrderManager om)
 		{
-			if (OrderManager != null) OrderManager.Dispose();
+			OrderManager?.Dispose();
 			OrderManager = om;
 			lastConnectionState = ConnectionState.PreConnecting;
 			ConnectionStateChanged(OrderManager);
@@ -154,8 +154,7 @@ internal static void SyncLobbyInfo()
 		internal static void StartGame(string mapUID, WorldType type)
 		{
 			// Dispose of the old world before creating a new one.
-			if (worldRenderer != null)
-				worldRenderer.Dispose();
+			worldRenderer?.Dispose();
 
 			Cursor.SetCursor(null);
 			BeforeGameStart();
@@ -330,11 +329,9 @@ static void Initialize(Arguments args)
 					Log.Write("graphics", "{0}", e);
 					Console.WriteLine("Renderer initialization failed. Check graphics.log for details.");
 
-					if (Renderer != null)
-						Renderer.Dispose();
+					Renderer?.Dispose();
 
-					if (Sound != null)
-						Sound.Dispose();
+					Sound?.Dispose();
 				}
 			}
 
@@ -388,13 +385,10 @@ public static void InitializeMod(string mod, Arguments args)
 
 			Ui.ResetAll();
 
-			if (worldRenderer != null)
-				worldRenderer.Dispose();
+			worldRenderer?.Dispose();
 			worldRenderer = null;
-			if (server != null)
-				server.Shutdown();
-			if (OrderManager != null)
-				OrderManager.Dispose();
+			server?.Shutdown();
+			OrderManager?.Dispose();
 
 			if (ModData != null)
 			{
@@ -430,8 +424,7 @@ public static void InitializeMod(string mod, Arguments args)
 			var grid = ModData.Manifest.Contains<MapGrid>() ? ModData.Manifest.Get<MapGrid>() : null;
 			Renderer.InitializeDepthBuffer(grid);
 
-			if (Cursor != null)
-				Cursor.Dispose();
+			Cursor?.Dispose();
 
 			Cursor = new CursorManager(ModData.CursorProvider);
 
@@ -446,8 +439,7 @@ public static void InitializeMod(string mod, Arguments args)
 
 			try
 			{
-				if (discoverNat != null)
-					discoverNat.Wait();
+				discoverNat?.Wait();
 			}
 			catch (Exception e)
 			{
@@ -610,8 +602,7 @@ static void InnerLogicTick(OrderManager orderManager)
 						Sync.RunUnsynced(Settings.Debug.SyncCheckUnsyncedCode, world, () => world.TickRender(worldRenderer));
 				}
 
-				if (benchmark != null)
-					benchmark.Tick(LocalTick);
+				benchmark?.Tick(LocalTick);
 			}
 		}
 
@@ -836,12 +827,10 @@ static RunStatus Run()
 			finally
 			{
 				// Ensure that the active replay is properly saved
-				if (OrderManager != null)
-					OrderManager.Dispose();
+				OrderManager?.Dispose();
 			}
 
-			if (worldRenderer != null)
-				worldRenderer.Dispose();
+			worldRenderer?.Dispose();
 			ModData.Dispose();
 			ChromeProvider.Deinitialize();
 
@@ -880,8 +869,7 @@ public static void Debug(string s, params object[] args)
 
 		public static void Disconnect()
 		{
-			if (OrderManager.World != null)
-				OrderManager.World.TraitDict.PrintReport();
+			OrderManager.World?.TraitDict.PrintReport();
 
 			OrderManager.Dispose();
 			CloseServer();
@@ -890,8 +878,7 @@ public static void Disconnect()
 
 		public static void CloseServer()
 		{
-			if (server != null)
-				server.Shutdown();
+			server?.Shutdown();
 		}
 
 		public static T CreateObject<T>(string name)

OpenRA.Game/Graphics/Animation.cs

@@ -156,7 +156,7 @@ public void PlayThen(string sequenceName, Action after)
 				{
 					frame = CurrentSequence.Length - 1;
 					tickFunc = () => { };
-					if (after != null) after();
+					after?.Invoke();
 				}
 			};
 		}

OpenRA.Game/Graphics/Sheet.cs

@@ -146,8 +146,7 @@ public void ReleaseBuffer()
 
 		public void Dispose()
 		{
-			if (texture != null)
-				texture.Dispose();
+			texture?.Dispose();
 		}
 	}
 }

OpenRA.Game/Graphics/WorldRenderer.cs

@@ -97,8 +97,8 @@ public void AddPalette(string name, ImmutablePalette pal, bool allowModifiers =
 				var oldHeight = palette.Height;
 				palette.AddPalette(name, pal, allowModifiers);
 
-				if (oldHeight != palette.Height && PaletteInvalidated != null)
-					PaletteInvalidated();
+				if (oldHeight != palette.Height)
+					PaletteInvalidated?.Invoke();
 			}
 		}
 
@@ -258,8 +258,7 @@ public void Draw()
 			if (enableDepthBuffer)
 				Game.Renderer.Context.EnableDepthBuffer();
 
-			if (terrainRenderer != null)
-				terrainRenderer.RenderTerrain(this, Viewport);
+			terrainRenderer?.RenderTerrain(this, Viewport);
 
 			Game.Renderer.Flush();
 

OpenRA.Game/InstalledMods.cs

@@ -78,8 +78,7 @@ Manifest LoadMod(string id, string path)
 				Log.Write("debug", "Load mod '{0}': {1}".F(path, e));
 			}
 
-			if (package != null)
-				package.Dispose();
+			package?.Dispose();
 
 			return null;
 		}

OpenRA.Game/LocalPlayerProfile.cs

@@ -108,8 +108,7 @@ public void RefreshPlayerData(Action onComplete = null)
 				}
 				finally
 				{
-					if (onComplete != null)
-						onComplete();
+					onComplete?.Invoke();
 				}
 			};
 

OpenRA.Game/Manifest.cs

@@ -245,8 +245,7 @@ public void Dispose()
 			foreach (var module in modules)
 			{
 				var disposableModule = module as IDisposable;
-				if (disposableModule != null)
-					disposableModule.Dispose();
+				disposableModule?.Dispose();
 			}
 		}
 	}

OpenRA.Game/Map/CellLayer.cs

@@ -73,8 +73,7 @@ public T this[CPos cell]
 			{
 				entries[Index(cell)] = value;
 
-				if (CellEntryChanged != null)
-					CellEntryChanged(cell);
+				CellEntryChanged?.Invoke(cell);
 			}
 		}
 
@@ -90,8 +89,7 @@ public T this[MPos uv]
 			{
 				entries[Index(uv)] = value;
 
-				if (CellEntryChanged != null)
-					CellEntryChanged(uv.ToCPos(GridType));
+				CellEntryChanged?.Invoke(uv.ToCPos(GridType));
 			}
 		}
 

OpenRA.Game/Map/MapCache.cs

@@ -111,8 +111,7 @@ public void LoadMaps()
 					}
 					catch (Exception e)
 					{
-						if (mapPackage != null)
-							mapPackage.Dispose();
+						mapPackage?.Dispose();
 						Console.WriteLine("Failed to load map: {0}", map);
 						Console.WriteLine("Details: {0}", e);
 						Log.Write("debug", "Failed to load map: {0}", map);
@@ -192,8 +191,7 @@ public void QueryRemoteMapDetails(string repositoryUrl, IEnumerable<string> uids
 					foreach (var p in maps.Values)
 						p.UpdateRemoteSearch(MapStatus.Unavailable, null);
 
-					if (queryFailed != null)
-						queryFailed();
+					queryFailed?.Invoke();
 
 					return;
 				}
@@ -213,8 +211,7 @@ public void QueryRemoteMapDetails(string repositoryUrl, IEnumerable<string> uids
 				{
 					Log.Write("debug", "Can't parse remote map search data:\n{0}", data);
 					Log.Write("debug", "Exception: {0}", e);
-					if (queryFailed != null)
-						queryFailed();
+					queryFailed?.Invoke();
 				}
 			};
 
@@ -298,8 +295,7 @@ public void CacheMinimap(MapPreview preview)
 				Game.RunAfterTick(() =>
 				{
 					// Wait for any existing thread to exit before starting a new one.
-					if (previewLoaderThread != null)
-						previewLoaderThread.Join();
+					previewLoaderThread?.Join();
 
 					previewLoaderThread = new Thread(LoadAsyncInternal)
 					{

OpenRA.Game/Map/MapPreview.cs

@@ -412,8 +412,7 @@ public void UpdateRemoteSearch(MapStatus status, MiniYaml yaml, Action<MapPrevie
 				if (innerData.Preview != null)
 					cache.CacheMinimap(this);
 
-				if (parseMetadata != null)
-					parseMetadata(this);
+				parseMetadata?.Invoke(this);
 			}
 
 			// Update the status and class unconditionally
@@ -522,9 +521,7 @@ public void Dispose()
 		public void Delete()
 		{
 			Invalidate();
-			var deleteFromPackage = parentPackage as IReadWritePackage;
-			if (deleteFromPackage != null)
-				deleteFromPackage.Delete(Package.Name);
+			(parentPackage as IReadWritePackage)?.Delete(Package.Name);
 		}
 
 		Stream IReadOnlyFileSystem.Open(string filename)