Use Null-Propagation Operator

2020-08-16 11:38:14 +02:00
parent 8d27d22100
commit 9c4fd0e3d3
113 changed files with 219 additions and 464 deletions
--- a/OpenRA.Mods.Common/Activities/Air/FlyAttack.cs
+++ b/OpenRA.Mods.Common/Activities/Air/FlyAttack.cs
@@ -128,8 +128,8 @@ namespace OpenRA.Mods.Common.Activities
 					return true;

 				// AbortOnResupply cancels the current activity (after resupplying) plus any queued activities
-				if (attackAircraft.Info.AbortOnResupply && NextActivity != null)
-					NextActivity.Cancel(self);
+				if (attackAircraft.Info.AbortOnResupply)
+					NextActivity?.Cancel(self);

 				QueueChild(new ReturnToBase(self));
 				returnToBase = true;
--- a/OpenRA.Mods.Common/Activities/CaptureActor.cs
+++ b/OpenRA.Mods.Common/Activities/CaptureActor.cs
@@ -112,11 +112,7 @@ namespace OpenRA.Mods.Common.Activities
 					t.OnCapture(enterActor, self, oldOwner, self.Owner, captures.Info.CaptureTypes);

 				if (self.Owner.Stances[oldOwner].HasStance(captures.Info.PlayerExperienceStances))
-				{
-					var exp = self.Owner.PlayerActor.TraitOrDefault<PlayerExperience>();
-					if (exp != null)
-						exp.GiveExperience(captures.Info.PlayerExperience);
-				}
+					self.Owner.PlayerActor.TraitOrDefault<PlayerExperience>()?.GiveExperience(captures.Info.PlayerExperience);

 				if (captures.Info.ConsumedByCapture)
 					self.Dispose();
--- a/OpenRA.Mods.Common/Activities/Move/Move.cs
+++ b/OpenRA.Mods.Common/Activities/Move/Move.cs
@@ -177,8 +177,7 @@ namespace OpenRA.Mods.Common.Activities

 			if (IsCanceling && mobile.CanStayInCell(mobile.ToCell))
 			{
-				if (path != null)
-					path.Clear();
+				path?.Clear();

 				return true;
 			}
--- a/OpenRA.Mods.Common/Activities/Resupply.cs
+++ b/OpenRA.Mods.Common/Activities/Resupply.cs
@@ -138,9 +138,7 @@ namespace OpenRA.Mods.Common.Activities
 					QueueChild(move.MoveTo(targetCell, targetLineColor: Color.Green));

 				var delta = (self.CenterPosition - host.CenterPosition).LengthSquared;
-				var transport = transportCallers.FirstOrDefault(t => t.MinimumDistance.LengthSquared < delta);
-				if (transport != null)
-					transport.RequestTransport(self, targetCell);
+				transportCallers.FirstOrDefault(t => t.MinimumDistance.LengthSquared < delta)?.RequestTransport(self, targetCell);

 				return false;
 			}
@@ -261,11 +259,7 @@ namespace OpenRA.Mods.Common.Activities
 			if (health.DamageState == DamageState.Undamaged)
 			{
 				if (host.Actor.Owner != self.Owner)
-				{
-					var exp = host.Actor.Owner.PlayerActor.TraitOrDefault<PlayerExperience>();
-					if (exp != null)
-						exp.GiveExperience(repairsUnits.Info.PlayerExperience);
-				}
+					host.Actor.Owner.PlayerActor.TraitOrDefault<PlayerExperience>()?.GiveExperience(repairsUnits.Info.PlayerExperience);

 				Game.Sound.PlayNotification(self.World.Map.Rules, self.Owner, "Speech", repairsUnits.Info.FinishRepairingNotification, self.Owner.Faction.InternalName);

--- a/OpenRA.Mods.Common/ColorValidator.cs
+++ b/OpenRA.Mods.Common/ColorValidator.cs
@@ -60,8 +60,7 @@ namespace OpenRA.Mods.Common
 			askedColor.ToAhsv(out _, out _, out var s, out var v);
 			if (s < HsvSaturationRange[0] || s > HsvSaturationRange[1] || v < HsvValueRange[0] || v > HsvValueRange[1])
 			{
-				if (errorMessages != null)
-					errorMessages.Add("Color was adjusted to be inside the allowed range.");
+				errorMessages?.Add("Color was adjusted to be inside the allowed range.");
 				forbiddenColor = askedColor;
 				return false;
 			}
@@ -69,16 +68,14 @@ namespace OpenRA.Mods.Common
 			// Validate color against the current map tileset
 			if (!IsValid(askedColor, terrainColors, out forbiddenColor))
 			{
-				if (errorMessages != null)
-					errorMessages.Add("Color was adjusted to be less similar to the terrain.");
+				errorMessages?.Add("Color was adjusted to be less similar to the terrain.");
 				return false;
 			}

 			// Validate color against other clients
 			if (!IsValid(askedColor, playerColors, out forbiddenColor))
 			{
-				if (errorMessages != null)
-					errorMessages.Add("Color was adjusted to be less similar to another player.");
+				errorMessages?.Add("Color was adjusted to be less similar to another player.");
 				return false;
 			}

--- a/OpenRA.Mods.Common/DiscordService.cs
+++ b/OpenRA.Mods.Common/DiscordService.cs
@@ -178,37 +178,27 @@ namespace OpenRA.Mods.Common

 		public static void UpdateStatus(DiscordState state, string details = null, string secret = null, int? players = null, int? slots = null)
 		{
-			var service = GetService();
-			if (service != null)
-				service.SetStatus(state, details, secret, players, slots);
+			GetService()?.SetStatus(state, details, secret, players, slots);
 		}

 		public static void SetPlayers(int players, int slots)
 		{
-			var service = GetService();
-			if (service != null)
+			GetService()?.client.UpdateParty(new Party
 			{
-				service.client.UpdateParty(new Party
-				{
-					ID = Secrets.CreateFriendlySecret(new Random()),
-					Size = players,
-					Max = slots
-				});
-			}
+				ID = Secrets.CreateFriendlySecret(new Random()),
+				Size = players,
+				Max = slots
+			});
 		}

 		public static void UpdatePlayers(int players, int slots)
 		{
-			var service = GetService();
-			if (service != null)
-				service.client.UpdatePartySize(players, slots);
+			GetService()?.client.UpdatePartySize(players, slots);
 		}

 		public static void UpdateDetails(string details)
 		{
-			var service = GetService();
-			if (service != null)
-				service.client.UpdateDetails(details);
+			GetService()?.client.UpdateDetails(details);
 		}
 	}
 }
--- a/OpenRA.Mods.Common/Effects/Beacon.cs
+++ b/OpenRA.Mods.Common/Effects/Beacon.cs
@@ -96,17 +96,10 @@ namespace OpenRA.Mods.Common.Effects
 				arrowSpeed *= -1;
 			}

-			if (arrow != null)
-				arrow.Tick();
-
-			if (beacon != null)
-				beacon.Tick();
-
-			if (circles != null)
-				circles.Tick();
-
-			if (clock != null)
-				clock.Tick();
+			arrow?.Tick();
+			beacon?.Tick();
+			circles?.Tick();
+			clock?.Tick();

 			if (duration > 0 && duration <= tick++)
 				owner.World.AddFrameEndTask(w => w.Remove(this));
--- a/OpenRA.Mods.Common/Effects/RallyPointIndicator.cs
+++ b/OpenRA.Mods.Common/Effects/RallyPointIndicator.cs
@@ -48,18 +48,15 @@ namespace OpenRA.Mods.Common.Effects

 		void IEffect.Tick(World world)
 		{
-			if (flag != null)
-				flag.Tick();
+			flag?.Tick();

-			if (circles != null)
-				circles.Tick();
+			circles?.Tick();

 			if (cachedLocations == null || !cachedLocations.SequenceEqual(rp.Path))
 			{
 				UpdateTargetLineNodes(world);

-				if (circles != null)
-					circles.Play(rp.Info.CirclesSequence);
+				circles?.Play(rp.Info.CirclesSequence);
 			}

 			if (!building.IsInWorld || building.IsDead)
--- a/OpenRA.Mods.Common/FileFormats/Blast.cs
+++ b/OpenRA.Mods.Common/FileFormats/Blast.cs
@@ -107,8 +107,7 @@ namespace OpenRA.Mods.Common.FileFormats
 						for (var i = 0; i < next; i++)
 							output.WriteByte(outBuffer[i]);

-						if (onProgress != null)
-							onProgress(input.Position - inputStart, output.Position - outputStart);
+						onProgress?.Invoke(input.Position - inputStart, output.Position - outputStart);
 						break;
 					}

@@ -155,8 +154,7 @@ namespace OpenRA.Mods.Common.FileFormats
 							next = 0;
 							first = false;

-							if (onProgress != null)
-								onProgress(input.Position - inputStart, output.Position - outputStart);
+							onProgress?.Invoke(input.Position - inputStart, output.Position - outputStart);
 						}
 					}
 					while (len != 0);
@@ -173,8 +171,7 @@ namespace OpenRA.Mods.Common.FileFormats
 						next = 0;
 						first = false;

-						if (onProgress != null)
-							onProgress(input.Position - inputStart, output.Position - outputStart);
+						onProgress?.Invoke(input.Position - inputStart, output.Position - outputStart);
 					}
 				}
 			}
--- a/OpenRA.Mods.Common/FileFormats/InstallShieldCABCompression.cs
+++ b/OpenRA.Mods.Common/FileFormats/InstallShieldCABCompression.cs
@@ -243,8 +243,7 @@ namespace OpenRA.Mods.Common.FileFormats
 						toExtract -= bytesToExtract;
 						while (!inf.IsNeedingInput)
 						{
-							if (onProgress != null)
-								onProgress((int)(100 * output.Position / file.ExpandedSize));
+							onProgress?.Invoke((int)(100 * output.Position / file.ExpandedSize));

 							var inflated = inf.Inflate(buffer);
 							output.Write(buffer, 0, inflated);
@@ -258,8 +257,7 @@ namespace OpenRA.Mods.Common.FileFormats
 				{
 					do
 					{
-						if (onProgress != null)
-							onProgress((int)(100 * output.Position / file.ExpandedSize));
+						onProgress?.Invoke((int)(100 * output.Position / file.ExpandedSize));

 						toExtract -= remainingInArchive;
 						output.Write(GetBytes(remainingInArchive), 0, (int)remainingInArchive);
--- a/OpenRA.Mods.Common/FileFormats/MSCabCompression.cs
+++ b/OpenRA.Mods.Common/FileFormats/MSCabCompression.cs
@@ -101,8 +101,7 @@ namespace OpenRA.Mods.Common.FileFormats
 			var decompressedBytes = 0;
 			for (var i = 0; i < folder.BlockCount; i++)
 			{
-				if (onProgress != null)
-					onProgress((int)(100 * output.Position / file.DecompressedLength));
+				onProgress?.Invoke((int)(100 * output.Position / file.DecompressedLength));

 				// Ignore checksums
 				stream.Position += 4;
--- a/OpenRA.Mods.Common/LoadScreens/SheetLoadScreen.cs
+++ b/OpenRA.Mods.Common/LoadScreens/SheetLoadScreen.cs
@@ -52,8 +52,7 @@ namespace OpenRA.Mods.Common.LoadScreens
 				dpiScale = scale;

 				// Force images to be reloaded on the next display
-				if (sheet != null)
-					sheet.Dispose();
+				sheet?.Dispose();

 				sheet = null;
 			}
@@ -94,8 +93,8 @@ namespace OpenRA.Mods.Common.LoadScreens

 		protected override void Dispose(bool disposing)
 		{
-			if (disposing && sheet != null)
-				sheet.Dispose();
+			if (disposing)
+				sheet?.Dispose();

 			base.Dispose(disposing);
 		}
--- a/OpenRA.Mods.Common/Orders/PlaceBuildingOrderGenerator.cs
+++ b/OpenRA.Mods.Common/Orders/PlaceBuildingOrderGenerator.cs
@@ -218,8 +218,7 @@ namespace OpenRA.Mods.Common.Orders
 				world.CancelInputMode();

 			foreach (var v in variants)
-				if (v.Preview != null)
-					v.Preview.Tick();
+				v.Preview?.Tick();
 		}

 		void IOrderGenerator.SelectionChanged(World world, IEnumerable<Actor> selected) { }
--- a/OpenRA.Mods.Common/Projectiles/Bullet.cs
+++ b/OpenRA.Mods.Common/Projectiles/Bullet.cs
@@ -197,8 +197,7 @@ namespace OpenRA.Mods.Common.Projectiles

 		public void Tick(World world)
 		{
-			if (anim != null)
-				anim.Tick();
+			anim?.Tick();

 			lastPos = pos;
 			pos = WPos.LerpQuadratic(source, target, angle, ticks, length);
--- a/OpenRA.Mods.Common/Projectiles/GravityBomb.cs
+++ b/OpenRA.Mods.Common/Projectiles/GravityBomb.cs
@@ -100,8 +100,7 @@ namespace OpenRA.Mods.Common.Projectiles
 				args.Weapon.Impact(Target.FromPos(pos), warheadArgs);
 			}

-			if (anim != null)
-				anim.Tick();
+			anim?.Tick();
 		}

 		public IEnumerable<IRenderable> Render(WorldRenderer wr)
--- a/OpenRA.Mods.Common/Projectiles/Missile.cs
+++ b/OpenRA.Mods.Common/Projectiles/Missile.cs
@@ -792,8 +792,7 @@ namespace OpenRA.Mods.Common.Projectiles
 		public void Tick(World world)
 		{
 			ticks++;
-			if (anim != null)
-				anim.Tick();
+			anim?.Tick();

 			// Switch from freefall mode to homing mode
 			if (ticks == info.HomingActivationDelay + 1)
--- a/OpenRA.Mods.Common/Projectiles/Railgun.cs
+++ b/OpenRA.Mods.Common/Projectiles/Railgun.cs
@@ -227,8 +227,7 @@ namespace OpenRA.Mods.Common.Projectiles
 				}
 			}

-			if (hitanim != null)
-				hitanim.Tick();
+			hitanim?.Tick();

 			if (ticks++ > info.Duration && animationComplete)
 				world.AddFrameEndTask(w => w.Remove(this));
--- a/OpenRA.Mods.Common/Scripting/CallLuaFunc.cs
+++ b/OpenRA.Mods.Common/Scripting/CallLuaFunc.cs
@@ -31,8 +31,7 @@ namespace OpenRA.Mods.Common.Activities
 		{
 			try
 			{
-				if (function != null)
-					function.Call().Dispose();
+				function?.Call().Dispose();
 			}
 			catch (Exception ex)
 			{
--- a/OpenRA.Mods.Common/Scripting/Global/RadarGlobal.cs
+++ b/OpenRA.Mods.Common/Scripting/Global/RadarGlobal.cs
@@ -29,14 +29,7 @@ namespace OpenRA.Mods.Common.Scripting
 		[Desc("Creates a new radar ping that stays for the specified time at the specified WPos.")]
 		public void Ping(Player player, WPos position, Color color, int duration = 30 * 25)
 		{
-			if (radarPings != null)
-			{
-				radarPings.Add(
-					() => player.World.RenderPlayer == player,
-					position,
-					color,
-					duration);
-			}
+			radarPings?.Add(() => player.World.RenderPlayer == player, position, color, duration);
 		}
 	}
 }
--- a/OpenRA.Mods.Common/Scripting/LuaScript.cs
+++ b/OpenRA.Mods.Common/Scripting/LuaScript.cs
@@ -54,8 +54,7 @@ namespace OpenRA.Mods.Common.Scripting
 			if (disposed)
 				return;

-			if (context != null)
-				context.Dispose();
+			context?.Dispose();

 			disposed = true;
 		}
--- a/OpenRA.Mods.Common/Scripting/Properties/GeneralProperties.cs
+++ b/OpenRA.Mods.Common/Scripting/Properties/GeneralProperties.cs
@@ -172,10 +172,7 @@ namespace OpenRA.Mods.Common.Scripting
 		{
 			get
 			{
-				if (autotarget == null)
-					return null;
-
-				return autotarget.Stance.ToString();
+				return autotarget?.Stance.ToString();
 			}

 			set
@@ -197,10 +194,8 @@ namespace OpenRA.Mods.Common.Scripting
 			get
 			{
 				var tooltip = tooltips.FirstEnabledTraitOrDefault();
-				if (tooltip == null)
-					return null;

-				return tooltip.Info.Name;
+				return tooltip?.Info.Name;
 			}
 		}

--- a/OpenRA.Mods.Common/ServerTraits/MasterServerPinger.cs
+++ b/OpenRA.Mods.Common/ServerTraits/MasterServerPinger.cs
@@ -98,8 +98,7 @@ namespace OpenRA.Mods.Common.Server

 		public void GameEnded(S server)
 		{
-			if (LanGameBeacon != null)
-				LanGameBeacon.Stop();
+			LanGameBeacon?.Stop();

 			lastChanged = Game.RunTime;
 		}
--- a/OpenRA.Mods.Common/Traits/BotModules/Squads/StateMachine.cs
+++ b/OpenRA.Mods.Common/Traits/BotModules/Squads/StateMachine.cs
@@ -18,8 +18,7 @@ namespace OpenRA.Mods.Common.Traits.BotModules.Squads

 		public void Update(Squad squad)
 		{
-			if (currentState != null)
-				currentState.Tick(squad);
+			currentState?.Tick(squad);
 		}

 		public void ChangeState(Squad squad, IState newState, bool rememberPrevious)
@@ -27,14 +26,12 @@ namespace OpenRA.Mods.Common.Traits.BotModules.Squads
 			if (rememberPrevious)
 				previousState = currentState;

-			if (currentState != null)
-				currentState.Deactivate(squad);
+			currentState?.Deactivate(squad);

 			if (newState != null)
 				currentState = newState;

-			if (currentState != null)
-				currentState.Activate(squad);
+			currentState?.Activate(squad);
 		}

 		public void RevertToPreviousState(Squad squad, bool saveCurrentState)
--- a/OpenRA.Mods.Common/Traits/Buildings/Bridge.cs
+++ b/OpenRA.Mods.Common/Traits/Buildings/Bridge.cs
@@ -302,8 +302,7 @@ namespace OpenRA.Mods.Common.Traits
 			// If this bridge repair operation connects two pathfinding domains,
 			// update the domain index.
 			var domainIndex = self.World.WorldActor.TraitOrDefault<DomainIndex>();
-			if (domainIndex != null)
-				domainIndex.UpdateCells(self.World, footprint.Keys);
+			domainIndex?.UpdateCells(self.World, footprint.Keys);

 			if (LongBridgeSegmentIsDead() && !killedUnits)
 			{
--- a/OpenRA.Mods.Common/Traits/Buildings/GroundLevelBridge.cs
+++ b/OpenRA.Mods.Common/Traits/Buildings/GroundLevelBridge.cs
@@ -70,9 +70,7 @@ namespace OpenRA.Mods.Common.Traits
 			foreach (var cell in cells)
 				self.World.Map.CustomTerrain[cell] = terrainIndex;

-			var domainIndex = self.World.WorldActor.TraitOrDefault<DomainIndex>();
-			if (domainIndex != null)
-				domainIndex.UpdateCells(self.World, cells);
+			self.World.WorldActor.TraitOrDefault<DomainIndex>()?.UpdateCells(self.World, cells);
 		}

 		void INotifyAddedToWorld.AddedToWorld(Actor self)
--- a/OpenRA.Mods.Common/Traits/Buildings/LineBuild.cs
+++ b/OpenRA.Mods.Common/Traits/Buildings/LineBuild.cs
@@ -91,10 +91,7 @@ namespace OpenRA.Mods.Common.Traits

 		void INotifyLineBuildSegmentsChanged.SegmentRemoved(Actor self, Actor segment)
 		{
-			if (segments == null)
-				return;
-
-			segments.Remove(segment);
+			segments?.Remove(segment);
 		}

 		void INotifyAddedToWorld.AddedToWorld(Actor self)
--- a/OpenRA.Mods.Common/Traits/Buildings/RepairableBuilding.cs
+++ b/OpenRA.Mods.Common/Traits/Buildings/RepairableBuilding.cs
@@ -172,9 +172,7 @@ namespace OpenRA.Mods.Common.Traits
 						if (r == self.Owner)
 							return;

-						var exp = r.PlayerActor.TraitOrDefault<PlayerExperience>();
-						if (exp != null)
-							exp.GiveExperience(Info.PlayerExperience);
+						r.PlayerActor.TraitOrDefault<PlayerExperience>()?.GiveExperience(Info.PlayerExperience);
 					});

 					Repairers.Clear();
--- a/OpenRA.Mods.Common/Traits/Buildings/TransformsIntoAircraft.cs
+++ b/OpenRA.Mods.Common/Traits/Buildings/TransformsIntoAircraft.cs
@@ -131,8 +131,8 @@ namespace OpenRA.Mods.Common.Traits

 			// Manually manage the inner activity queue
 			var activity = currentTransform ?? transform.GetTransformActivity(self);
-			if (!order.Queued && activity.NextActivity != null)
-				activity.NextActivity.Cancel(self);
+			if (!order.Queued)
+				activity.NextActivity?.Cancel(self);

 			activity.Queue(new IssueOrderAfterTransform(order.OrderString, order.Target, Color.Green));

--- a/OpenRA.Mods.Common/Traits/Buildings/TransformsIntoEntersTunnels.cs
+++ b/OpenRA.Mods.Common/Traits/Buildings/TransformsIntoEntersTunnels.cs
@@ -95,8 +95,8 @@ namespace OpenRA.Mods.Common.Traits

 			// Manually manage the inner activity queue
 			var activity = currentTransform ?? transform.GetTransformActivity(self);
-			if (!order.Queued && activity.NextActivity != null)
-				activity.NextActivity.Cancel(self);
+			if (!order.Queued)
+				activity.NextActivity?.Cancel(self);

 			activity.Queue(new IssueOrderAfterTransform(order.OrderString, order.Target, Color.Green));

--- a/OpenRA.Mods.Common/Traits/Buildings/TransformsIntoMobile.cs
+++ b/OpenRA.Mods.Common/Traits/Buildings/TransformsIntoMobile.cs
@@ -110,8 +110,8 @@ namespace OpenRA.Mods.Common.Traits

 				// Manually manage the inner activity queue
 				var activity = currentTransform ?? transform.GetTransformActivity(self);
-				if (!order.Queued && activity.NextActivity != null)
-					activity.NextActivity.Cancel(self);
+				if (!order.Queued)
+					activity.NextActivity?.Cancel(self);

 				activity.Queue(new IssueOrderAfterTransform("Move", order.Target, Color.Green));

--- a/OpenRA.Mods.Common/Traits/Buildings/TransformsIntoPassenger.cs
+++ b/OpenRA.Mods.Common/Traits/Buildings/TransformsIntoPassenger.cs
@@ -129,8 +129,8 @@ namespace OpenRA.Mods.Common.Traits

 			// Manually manage the inner activity queue
 			var activity = currentTransform ?? transform.GetTransformActivity(self);
-			if (!order.Queued && activity.NextActivity != null)
-				activity.NextActivity.Cancel(self);
+			if (!order.Queued)
+				activity.NextActivity?.Cancel(self);

 			activity.Queue(new IssueOrderAfterTransform(order.OrderString, order.Target, Color.Green));

--- a/OpenRA.Mods.Common/Traits/Buildings/TransformsIntoRepairable.cs
+++ b/OpenRA.Mods.Common/Traits/Buildings/TransformsIntoRepairable.cs
@@ -123,8 +123,8 @@ namespace OpenRA.Mods.Common.Traits

 			// Manually manage the inner activity queue
 			var activity = currentTransform ?? transform.GetTransformActivity(self);
-			if (!order.Queued && activity.NextActivity != null)
-				activity.NextActivity.Cancel(self);
+			if (!order.Queued)
+				activity.NextActivity?.Cancel(self);

 			activity.Queue(new IssueOrderAfterTransform(order.OrderString, order.Target, Color.Green));

--- a/OpenRA.Mods.Common/Traits/Buildings/TransformsIntoTransforms.cs
+++ b/OpenRA.Mods.Common/Traits/Buildings/TransformsIntoTransforms.cs
@@ -41,8 +41,8 @@ namespace OpenRA.Mods.Common.Traits
 			if (!order.Queued || currentTransform == null)
 				return;

-			if (!order.Queued && currentTransform.NextActivity != null)
-				currentTransform.NextActivity.Cancel(self);
+			if (!order.Queued)
+				currentTransform.NextActivity?.Cancel(self);

 			currentTransform.Queue(new IssueOrderAfterTransform("DeployTransform", order.Target, Color.Green));

--- a/OpenRA.Mods.Common/Traits/Conditions/GrantExternalConditionToCrusher.cs
+++ b/OpenRA.Mods.Common/Traits/Conditions/GrantExternalConditionToCrusher.cs
@@ -44,20 +44,16 @@ namespace OpenRA.Mods.Common.Traits

 		void INotifyCrushed.OnCrush(Actor self, Actor crusher, BitSet<CrushClass> crushClasses)
 		{
-			var external = crusher.TraitsImplementing<ExternalCondition>()
-				.FirstOrDefault(t => t.Info.Condition == Info.OnCrushCondition && t.CanGrantCondition(crusher, self));
-
-			if (external != null)
-				external.GrantCondition(crusher, self, Info.OnCrushDuration);
+			crusher.TraitsImplementing<ExternalCondition>()
+				.FirstOrDefault(t => t.Info.Condition == Info.OnCrushCondition && t.CanGrantCondition(crusher, self))
+				?.GrantCondition(crusher, self, Info.OnCrushDuration);
 		}

 		void INotifyCrushed.WarnCrush(Actor self, Actor crusher, BitSet<CrushClass> crushClasses)
 		{
-			var external = crusher.TraitsImplementing<ExternalCondition>()
-				.FirstOrDefault(t => t.Info.Condition == Info.WarnCrushCondition && t.CanGrantCondition(crusher, self));
-
-			if (external != null)
-				external.GrantCondition(crusher, self, Info.WarnCrushDuration);
+			crusher.TraitsImplementing<ExternalCondition>()
+				.FirstOrDefault(t => t.Info.Condition == Info.WarnCrushCondition && t.CanGrantCondition(crusher, self))
+				?.GrantCondition(crusher, self, Info.WarnCrushDuration);
 		}
 	}
 }
--- a/OpenRA.Mods.Common/Traits/Conditions/GrantExternalConditionToProduced.cs
+++ b/OpenRA.Mods.Common/Traits/Conditions/GrantExternalConditionToProduced.cs
@@ -36,11 +36,9 @@ namespace OpenRA.Mods.Common.Traits
 			if (IsTraitDisabled || other.IsDead)
 				return;

-			var external = other.TraitsImplementing<ExternalCondition>()
-				.FirstOrDefault(t => t.Info.Condition == Info.Condition && t.CanGrantCondition(other, self));
-
-			if (external != null)
-				external.GrantCondition(other, self, Info.Duration);
+			other.TraitsImplementing<ExternalCondition>()
+				.FirstOrDefault(t => t.Info.Condition == Info.Condition && t.CanGrantCondition(other, self))
+				?.GrantCondition(other, self, Info.Duration);
 		}
 	}
 }
--- a/OpenRA.Mods.Common/Traits/Crates/Crate.cs
+++ b/OpenRA.Mods.Common/Traits/Crates/Crate.cs
@@ -248,9 +248,7 @@ namespace OpenRA.Mods.Common.Traits
 		{
 			self.World.AddToMaps(self, this);

-			var cs = self.World.WorldActor.TraitOrDefault<CrateSpawner>();
-			if (cs != null)
-				cs.IncrementCrates();
+			self.World.WorldActor.TraitOrDefault<CrateSpawner>()?.IncrementCrates();

 			if (self.World.Map.DistanceAboveTerrain(CenterPosition) > WDist.Zero && self.TraitOrDefault<Parachutable>() != null)
 				self.QueueActivity(new Parachute(self));
@@ -260,9 +258,7 @@ namespace OpenRA.Mods.Common.Traits
 		{
 			self.World.RemoveFromMaps(self, this);

-			var cs = self.World.WorldActor.TraitOrDefault<CrateSpawner>();
-			if (cs != null)
-				cs.DecrementCrates();
+			self.World.WorldActor.TraitOrDefault<CrateSpawner>()?.DecrementCrates();
 		}
 	}
 }
--- a/OpenRA.Mods.Common/Traits/Crates/LevelUpCrateAction.cs
+++ b/OpenRA.Mods.Common/Traits/Crates/LevelUpCrateAction.cs
@@ -72,9 +72,7 @@ namespace OpenRA.Mods.Common.Traits
 				var recipient = actor;	// loop variable in closure hazard
 				recipient.World.AddFrameEndTask(w =>
 				{
-					var gainsExperience = recipient.TraitOrDefault<GainsExperience>();
-					if (gainsExperience != null)
-						gainsExperience.GiveLevels(info.Levels);
+					recipient.TraitOrDefault<GainsExperience>()?.GiveLevels(info.Levels);
 				});
 			}

--- a/OpenRA.Mods.Common/Traits/EjectOnDeath.cs
+++ b/OpenRA.Mods.Common/Traits/EjectOnDeath.cs
@@ -90,11 +90,7 @@ namespace OpenRA.Mods.Common.Traits
 				var pilot = self.World.CreateActor(true, Info.PilotActor.ToLowerInvariant(), td);

 				if (!inAir)
-				{
-					var pilotMobile = pilot.TraitOrDefault<Mobile>();
-					if (pilotMobile != null)
-						pilotMobile.Nudge(pilot);
-				}
+					pilot.TraitOrDefault<Mobile>()?.Nudge(pilot);
 				else
 					Game.Sound.Play(SoundType.World, Info.ChuteSound, cp);
 			});
--- a/OpenRA.Mods.Common/Traits/GivesExperience.cs
+++ b/OpenRA.Mods.Common/Traits/GivesExperience.cs
@@ -66,9 +66,8 @@ namespace OpenRA.Mods.Common.Traits
 				killer.GiveExperience(Util.ApplyPercentageModifiers(exp, killerExperienceModifier));
 			}

-			var attackerExp = e.Attacker.Owner.PlayerActor.TraitOrDefault<PlayerExperience>();
-			if (attackerExp != null)
-				attackerExp.GiveExperience(Util.ApplyPercentageModifiers(exp, new[] { info.PlayerExperienceModifier }));
+			e.Attacker.Owner.PlayerActor.TraitOrDefault<PlayerExperience>()
+				?.GiveExperience(Util.ApplyPercentageModifiers(exp, new[] { info.PlayerExperienceModifier }));
 		}
 	}
 }
--- a/OpenRA.Mods.Common/Traits/Player/AllyRepair.cs
+++ b/OpenRA.Mods.Common/Traits/Player/AllyRepair.cs
@@ -26,9 +26,7 @@ namespace OpenRA.Mods.Common.Traits
 				if (!building.AppearsFriendlyTo(self))
 					return;

-				var rb = building.TraitOrDefault<RepairableBuilding>();
-				if (rb != null)
-					rb.RepairBuilding(building, self.Owner);
+				building.TraitOrDefault<RepairableBuilding>()?.RepairBuilding(building, self.Owner);
 			}
 		}
 	}
--- a/OpenRA.Mods.Common/Traits/Player/BaseAttackNotifier.cs
+++ b/OpenRA.Mods.Common/Traits/Player/BaseAttackNotifier.cs
@@ -80,8 +80,7 @@ namespace OpenRA.Mods.Common.Traits
 						if (p != self.Owner && p.IsAlliedWith(self.Owner) && p != e.Attacker.Owner)
 							Game.Sound.PlayNotification(rules, p, "Speech", info.AllyNotification, p.Faction.InternalName);

-				if (radarPings != null)
-					radarPings.Add(() => self.Owner.IsAlliedWith(self.World.RenderPlayer), self.CenterPosition, info.RadarPingColor, info.RadarPingDuration);
+				radarPings?.Add(() => self.Owner.IsAlliedWith(self.World.RenderPlayer), self.CenterPosition, info.RadarPingColor, info.RadarPingDuration);
 			}

 			lastAttackTime = self.World.WorldTick;
--- a/OpenRA.Mods.Common/Traits/Player/DeveloperMode.cs
+++ b/OpenRA.Mods.Common/Traits/Player/DeveloperMode.cs
@@ -244,10 +244,7 @@ namespace OpenRA.Mods.Common.Traits

 				case "DevPlayerExperience":
 				{
-					var playerExperience = self.Owner.PlayerActor.TraitOrDefault<PlayerExperience>();
-					if (playerExperience != null)
-						playerExperience.GiveExperience((int)order.ExtraData);
-
+					self.Owner.PlayerActor.TraitOrDefault<PlayerExperience>()?.GiveExperience((int)order.ExtraData);
 					break;
 				}

--- a/OpenRA.Mods.Common/Traits/Player/HarvesterAttackNotifier.cs
+++ b/OpenRA.Mods.Common/Traits/Player/HarvesterAttackNotifier.cs
@@ -61,8 +61,7 @@ namespace OpenRA.Mods.Common.Traits
 			{
 				Game.Sound.PlayNotification(self.World.Map.Rules, self.Owner, "Speech", info.Notification, self.Owner.Faction.InternalName);

-				if (radarPings != null)
-					radarPings.Add(() => self.Owner.IsAlliedWith(self.World.RenderPlayer), self.CenterPosition, info.RadarPingColor, info.RadarPingDuration);
+				radarPings?.Add(() => self.Owner.IsAlliedWith(self.World.RenderPlayer), self.CenterPosition, info.RadarPingColor, info.RadarPingDuration);
 			}

 			lastAttackTime = self.World.WorldTick;
--- a/OpenRA.Mods.Common/Traits/Player/PlaceBuilding.cs
+++ b/OpenRA.Mods.Common/Traits/Player/PlaceBuilding.cs
@@ -170,8 +170,7 @@ namespace OpenRA.Mods.Common.Traits
 						foreach (var t in buildingInfo.Tiles(targetLocation))
 						{
 							var host = buildingInfluence.GetBuildingAt(t);
-							if (host != null)
-								host.World.Remove(host);
+							host?.World.Remove(host);
 						}
 					}

@@ -193,14 +192,10 @@ namespace OpenRA.Mods.Common.Traits

 				queue.EndProduction(item);

+				// FindBaseProvider may return null if the build anywhere cheat is active
+				// BuildingInfo.IsCloseEnoughToBase has already verified that this is a valid build location
 				if (buildingInfo.RequiresBaseProvider)
-				{
-					// May be null if the build anywhere cheat is active
-					// BuildingInfo.IsCloseEnoughToBase has already verified that this is a valid build location
-					var provider = buildingInfo.FindBaseProvider(w, self.Owner, targetLocation);
-					if (provider != null)
-						provider.BeginCooldown();
-				}
+					buildingInfo.FindBaseProvider(w, self.Owner, targetLocation)?.BeginCooldown();

 				if (GetNumBuildables(self.Owner) > prevItems)
 					triggerNotification = true;
--- a/OpenRA.Mods.Common/Traits/Player/PlayerRadarTerrain.cs
+++ b/OpenRA.Mods.Common/Traits/Player/PlayerRadarTerrain.cs
@@ -61,8 +61,7 @@ namespace OpenRA.Mods.Common.Traits
 		{
 			terrainColor[uv] = GetColor(world.Map, uv);

-			if (CellTerrainColorChanged != null)
-				CellTerrainColorChanged(uv);
+			CellTerrainColorChanged?.Invoke(uv);
 		}

 		public void WorldLoaded(World w, WorldRenderer wr)
--- a/OpenRA.Mods.Common/Traits/Player/ProductionQueue.cs
+++ b/OpenRA.Mods.Common/Traits/Player/ProductionQueue.cs
@@ -465,9 +465,7 @@ namespace OpenRA.Mods.Common.Traits

 		protected void PauseProduction(string itemName, bool paused)
 		{
-			var item = Queue.FirstOrDefault(a => a.Item == itemName);
-			if (item != null)
-				item.Pause(paused);
+			Queue.FirstOrDefault(a => a.Item == itemName)?.Pause(paused);
 		}

 		protected void CancelProduction(string itemName, uint numberToCancel)
@@ -646,8 +644,7 @@ namespace OpenRA.Mods.Common.Traits

 			if (Done)
 			{
-				if (OnComplete != null)
-					OnComplete();
+				OnComplete?.Invoke();

 				return;
 			}
--- a/OpenRA.Mods.Common/Traits/Render/WithMakeAnimation.cs
+++ b/OpenRA.Mods.Common/Traits/Render/WithMakeAnimation.cs
@@ -105,14 +105,11 @@ namespace OpenRA.Mods.Common.Traits.Render
 		{
 			Reverse(self, () =>
 			{
-				var wsb = wsbs.FirstEnabledTraitOrDefault();
-
 				// HACK: The actor remains alive and active for one tick before the followup activity
 				// (sell/transform/etc) runs. This causes visual glitches that we attempt to minimize
 				// by forcing the animation to frame 0 and regranting the make condition.
 				// These workarounds will break the actor if the followup activity doesn't dispose it!
-				if (wsb != null)
-					wsb.DefaultAnimation.PlayFetchIndex(info.Sequence, () => 0);
+				wsbs.FirstEnabledTraitOrDefault()?.DefaultAnimation.PlayFetchIndex(info.Sequence, () => 0);

 				token = self.GrantCondition(info.Condition);

--- a/OpenRA.Mods.Common/Traits/Render/WithParachute.cs
+++ b/OpenRA.Mods.Common/Traits/Render/WithParachute.cs
@@ -159,8 +159,7 @@ namespace OpenRA.Mods.Common.Traits.Render

 		void ITick.Tick(Actor self)
 		{
-			if (shadow != null)
-				shadow.Tick();
+			shadow?.Tick();
 		}

 		IEnumerable<IRenderable> IRender.Render(Actor self, WorldRenderer wr)
--- a/OpenRA.Mods.Common/Traits/Render/WithSpriteBody.cs
+++ b/OpenRA.Mods.Common/Traits/Render/WithSpriteBody.cs
@@ -97,8 +97,7 @@ namespace OpenRA.Mods.Common.Traits.Render
 			DefaultAnimation.PlayThen(NormalizeSequence(self, name), () =>
 			{
 				CancelCustomAnimation(self);
-				if (after != null)
-					after();
+				after?.Invoke();
 			});
 		}

@@ -112,8 +111,7 @@ namespace OpenRA.Mods.Common.Traits.Render
 			DefaultAnimation.PlayBackwardsThen(NormalizeSequence(self, name), () =>
 			{
 				CancelCustomAnimation(self);
-				if (after != null)
-					after();
+				after?.Invoke();
 			});
 		}

--- a/OpenRA.Mods.Common/Traits/Render/WithSpriteTurret.cs
+++ b/OpenRA.Mods.Common/Traits/Render/WithSpriteTurret.cs
@@ -132,8 +132,7 @@ namespace OpenRA.Mods.Common.Traits.Render
 			DefaultAnimation.PlayThen(NormalizeSequence(self, name), () =>
 			{
 				CancelCustomAnimation(self);
-				if (after != null)
-					after();
+				after?.Invoke();
 			});
 		}

--- a/OpenRA.Mods.Common/Traits/Sound/AnnounceOnSeen.cs
+++ b/OpenRA.Mods.Common/Traits/Sound/AnnounceOnSeen.cs
@@ -57,8 +57,8 @@ namespace OpenRA.Mods.Common.Traits.Sound
 				Game.Sound.PlayNotification(self.World.Map.Rules, discoverer, "Speech", Info.Notification, discoverer.Faction.InternalName);

 			// Radar notification
-			if (Info.PingRadar && radarPings.Value != null)
-				radarPings.Value.Add(() => true, self.CenterPosition, Color.Red, 50);
+			if (Info.PingRadar)
+				radarPings.Value?.Add(() => true, self.CenterPosition, Color.Red, 50);
 		}
 	}
 }
--- a/OpenRA.Mods.Common/Traits/SupportPowers/GrantExternalConditionPower.cs
+++ b/OpenRA.Mods.Common/Traits/SupportPowers/GrantExternalConditionPower.cs
@@ -83,13 +83,9 @@ namespace OpenRA.Mods.Common.Traits
 			Game.Sound.Play(SoundType.World, info.OnFireSound, order.Target.CenterPosition);

 			foreach (var a in UnitsInRange(self.World.Map.CellContaining(order.Target.CenterPosition)))
-			{
-				var external = a.TraitsImplementing<ExternalCondition>()
-					.FirstOrDefault(t => t.Info.Condition == info.Condition && t.CanGrantCondition(a, self));
-
-				if (external != null)
-					external.GrantCondition(a, self, info.Duration);
-			}
+				a.TraitsImplementing<ExternalCondition>()
+					.FirstOrDefault(t => t.Info.Condition == info.Condition && t.CanGrantCondition(a, self))
+					?.GrantCondition(a, self, info.Duration);
 		}

 		public IEnumerable<Actor> UnitsInRange(CPos xy)
--- a/OpenRA.Mods.Common/Traits/SupportPowers/SupportPowerManager.cs
+++ b/OpenRA.Mods.Common/Traits/SupportPowers/SupportPowerManager.cs
@@ -227,10 +227,8 @@ namespace OpenRA.Mods.Common.Traits
 				return;

 			var power = Instances.FirstOrDefault(i => !i.IsTraitPaused);
-			if (power == null)
-				return;

-			power.SelectTarget(power.Self, Key, Manager);
+			power?.SelectTarget(power.Self, Key, Manager);
 		}

 		public virtual void Activate(Order order)
--- a/OpenRA.Mods.Common/Traits/World/ActorMap.cs
+++ b/OpenRA.Mods.Common/Traits/World/ActorMap.cs
@@ -381,8 +381,7 @@ namespace OpenRA.Mods.Common.Traits
 					foreach (var t in triggers)
 						t.Dirty = true;

-				if (CellUpdated != null)
-					CellUpdated(c.Cell);
+				CellUpdated?.Invoke(c.Cell);
 			}
 		}

@@ -403,8 +402,7 @@ namespace OpenRA.Mods.Common.Traits
 					foreach (var t in triggers)
 						t.Dirty = true;

-				if (CellUpdated != null)
-					CellUpdated(c.Cell);
+				CellUpdated?.Invoke(c.Cell);
 			}
 		}

--- a/OpenRA.Mods.Common/Traits/World/EditorActionManager.cs
+++ b/OpenRA.Mods.Common/Traits/World/EditorActionManager.cs
@@ -49,8 +49,7 @@ namespace OpenRA.Mods.Common.Traits
 			ClearRedo();
 			undoStack.Push(actionContainer);

-			if (ItemAdded != null)
-				ItemAdded(actionContainer);
+			ItemAdded?.Invoke(actionContainer);
 		}

 		public void Undo()
@@ -66,8 +65,7 @@ namespace OpenRA.Mods.Common.Traits
 			editorAction.Status = EditorActionStatus.Future;
 			redoStack.Push(editorAction);

-			if (OnChange != null)
-				OnChange();
+			OnChange?.Invoke();
 		}

 		void ClearRedo()
@@ -76,8 +74,7 @@ namespace OpenRA.Mods.Common.Traits
 			{
 				var item = redoStack.Pop();

-				if (ItemRemoved != null)
-					ItemRemoved(item);
+				ItemRemoved?.Invoke(item);
 			}
 		}

@@ -95,8 +92,7 @@ namespace OpenRA.Mods.Common.Traits
 			undoStack.Peek().Status = EditorActionStatus.History;
 			undoStack.Push(editorAction);

-			if (OnChange != null)
-				OnChange();
+			OnChange?.Invoke();
 		}

 		public bool HasUndos()
--- a/OpenRA.Mods.Common/Traits/World/EditorResourceLayer.cs
+++ b/OpenRA.Mods.Common/Traits/World/EditorResourceLayer.cs
@@ -92,8 +92,7 @@ namespace OpenRA.Mods.Common.Traits
 			UpdateNetWorth(t.Type, t.Density, newTile.Type, newTile.Density);
 			Tiles[uv] = newTile;
 			Map.CustomTerrain[uv] = newTerrain;
-			if (CellChanged != null)
-				CellChanged(cell, type);
+			CellChanged?.Invoke(cell, type);

 			// Neighbouring cell density depends on this cell
 			foreach (var d in CVec.Directions)
@@ -111,8 +110,7 @@ namespace OpenRA.Mods.Common.Traits
 				neighbouringTile.Density = density;
 				Tiles[neighbouringCell] = neighbouringTile;

-				if (CellChanged != null)
-					CellChanged(neighbouringCell, type);
+				CellChanged?.Invoke(neighbouringCell, type);
 			}
 		}

--- a/OpenRA.Mods.Common/Traits/World/ResourceLayer.cs
+++ b/OpenRA.Mods.Common/Traits/World/ResourceLayer.cs
@@ -158,8 +158,7 @@ namespace OpenRA.Mods.Common.Traits
 			cell.Density = Math.Min(cell.Type.Info.MaxDensity, cell.Density + n);
 			Content[p] = cell;

-			if (CellChanged != null)
-				CellChanged(p, cell.Type);
+			CellChanged?.Invoke(p, cell.Type);
 		}

 		public bool IsFull(CPos cell)
@@ -183,8 +182,7 @@ namespace OpenRA.Mods.Common.Traits
 			else
 				Content[cell] = c;

-			if (CellChanged != null)
-				CellChanged(cell, c.Type);
+			CellChanged?.Invoke(cell, c.Type);

 			return c.Type;
 		}
@@ -202,8 +200,7 @@ namespace OpenRA.Mods.Common.Traits
 			Content[cell] = ResourceLayerContents.Empty;
 			world.Map.CustomTerrain[cell] = byte.MaxValue;

-			if (CellChanged != null)
-				CellChanged(cell, c.Type);
+			CellChanged?.Invoke(cell, c.Type);
 		}

 		public ResourceType GetResourceType(CPos cell) { return Content[cell].Type; }
--- a/OpenRA.Mods.Common/UpdateRules/Rules/20200503/MoveClassicFacingFudge.cs
+++ b/OpenRA.Mods.Common/UpdateRules/Rules/20200503/MoveClassicFacingFudge.cs
@@ -70,8 +70,7 @@ namespace OpenRA.Mods.Common.UpdateRules.Rules
 			foreach (var sequence in sequenceNode.Value.Nodes)
 			{
 				var facingFudgeNode = sequence.LastChildMatching("UseClassicFacingFudge");
-				if (facingFudgeNode != null)
-					facingFudgeNode.RenameKey("UseClassicFacings");
+				facingFudgeNode?.RenameKey("UseClassicFacings");
 			}

 			yield break;
--- a/OpenRA.Mods.Common/UpdateRules/UpdateUtils.cs
+++ b/OpenRA.Mods.Common/UpdateRules/UpdateUtils.cs
@@ -263,8 +263,7 @@ namespace OpenRA.Mods.Common.UpdateRules
 		public static void Save(this YamlFileSet files)
 		{
 			foreach (var file in files)
-				if (file.Item1 != null)
-					file.Item1.Update(file.Item2, Encoding.UTF8.GetBytes(file.Item3.WriteToString()));
+				file.Item1?.Update(file.Item2, Encoding.UTF8.GetBytes(file.Item3.WriteToString()));
 		}

 		/// <summary>Checks if node is a removal (has '-' prefix)</summary>
--- a/OpenRA.Mods.Common/Warheads/GrantExternalConditionWarhead.cs
+++ b/OpenRA.Mods.Common/Warheads/GrantExternalConditionWarhead.cs
@@ -38,11 +38,9 @@ namespace OpenRA.Mods.Common.Warheads
 				if (!IsValidAgainst(a, firedBy))
 					continue;

-				var external = a.TraitsImplementing<ExternalCondition>()
-					.FirstOrDefault(t => t.Info.Condition == Condition && t.CanGrantCondition(a, firedBy));
-
-				if (external != null)
-					external.GrantCondition(a, firedBy, Duration);
+				a.TraitsImplementing<ExternalCondition>()
+					.FirstOrDefault(t => t.Info.Condition == Condition && t.CanGrantCondition(a, firedBy))
+					?.GrantCondition(a, firedBy, Duration);
 			}
 		}
 	}
--- a/OpenRA.Mods.Common/Widgets/ConfirmationDialogs.cs
+++ b/OpenRA.Mods.Common/Widgets/ConfirmationDialogs.cs
@@ -71,8 +71,7 @@ namespace OpenRA.Mods.Common.Widgets
 				cancelButton.OnClick = () =>
 				{
 					Ui.CloseWindow();
-					if (onCancel != null)
-						onCancel();
+					onCancel?.Invoke();
 				};

 				if (!string.IsNullOrEmpty(cancelText) && cancelButton != null)
@@ -85,8 +84,7 @@ namespace OpenRA.Mods.Common.Widgets
 				otherButton.Bounds.Y += headerHeight;
 				otherButton.OnClick = () =>
 				{
-					if (onOther != null)
-						onOther();
+					onOther?.Invoke();
 				};

 				if (!string.IsNullOrEmpty(otherText) && otherButton != null)
@@ -156,8 +154,7 @@ namespace OpenRA.Mods.Common.Widgets
 			cancelButton.OnClick = () =>
 			{
 				Ui.CloseWindow();
-				if (onCancel != null)
-					onCancel();
+				onCancel?.Invoke();
 			};

 			// Validation
--- a/OpenRA.Mods.Common/Widgets/DropDownButtonWidget.cs
+++ b/OpenRA.Mods.Common/Widgets/DropDownButtonWidget.cs
@@ -129,9 +129,7 @@ namespace OpenRA.Mods.Common.Widgets
 				oldBounds.Height);
 			panelRoot.AddChild(panel);

-			var scrollPanel = panel as ScrollPanelWidget;
-			if (scrollPanel != null)
-				scrollPanel.ScrollToSelectedItem();
+			(panel as ScrollPanelWidget)?.ScrollToSelectedItem();
 		}

 		public void ShowDropDown<T>(string panelTemplate, int maxHeight, IEnumerable<T> options, Func<T, ScrollItemWidget, ScrollItemWidget> setupItem)
--- a/OpenRA.Mods.Common/Widgets/EditorViewportControllerWidget.cs
+++ b/OpenRA.Mods.Common/Widgets/EditorViewportControllerWidget.cs
@@ -52,8 +52,7 @@ namespace OpenRA.Mods.Common.Widgets
 		public void ClearBrush() { SetBrush(null); }
 		public void SetBrush(IEditorBrush brush)
 		{
-			if (CurrentBrush != null)
-				CurrentBrush.Dispose();
+			CurrentBrush?.Dispose();

 			CurrentBrush = brush ?? DefaultBrush;
 		}
--- a/OpenRA.Mods.Common/Widgets/Logic/ColorPickerLogic.cs
+++ b/OpenRA.Mods.Common/Widgets/Logic/ColorPickerLogic.cs
@@ -40,8 +40,7 @@ namespace OpenRA.Mods.Common.Widgets.Logic
 				foreach (var o in api.ActorPreviewInits(actor, ActorPreviewType.ColorPicker))
 					td.Add(o);

-			if (preview != null)
-				preview.SetPreview(actor, td);
+			preview?.SetPreview(actor, td);

 			var hueSlider = widget.Get<SliderWidget>("HUE");
 			var mixer = widget.Get<ColorMixerWidget>("MIXER");
--- a/OpenRA.Mods.Common/Widgets/Logic/Editor/ActorEditLogic.cs
+++ b/OpenRA.Mods.Common/Widgets/Logic/Editor/ActorEditLogic.cs
@@ -375,8 +375,7 @@ namespace OpenRA.Mods.Common.Widgets.Logic

 		void Reset()
 		{
-			if (editActorPreview != null)
-				editActorPreview.Reset();
+			editActorPreview?.Reset();
 		}

 		void Close()
--- a/OpenRA.Mods.Common/Widgets/Logic/Editor/CommonSelectorLogic.cs
+++ b/OpenRA.Mods.Common/Widgets/Logic/Editor/CommonSelectorLogic.cs
@@ -71,8 +71,7 @@ namespace OpenRA.Mods.Common.Widgets.Logic

 			categorySelector.OnMouseDown = _ =>
 			{
-				if (SearchTextField != null)
-					SearchTextField.YieldKeyboardFocus();
+				SearchTextField?.YieldKeyboardFocus();

 				categorySelector.RemovePanel();
 				categorySelector.AttachPanel(CreateCategoriesPanel(Panel));
--- a/OpenRA.Mods.Common/Widgets/Logic/Ingame/IngameChatLogic.cs
+++ b/OpenRA.Mods.Common/Widgets/Logic/Ingame/IngameChatLogic.cs
@@ -233,8 +233,7 @@ namespace OpenRA.Mods.Common.Widgets.Logic

 		public void AddChatLineWrapper(string name, Color nameColor, string text, Color textColor)
 		{
-			if (chatOverlayDisplay != null)
-				chatOverlayDisplay.AddLine(name, nameColor, text, textColor);
+			chatOverlayDisplay?.AddLine(name, nameColor, text, textColor);

 			// HACK: Force disable the chat notification sound for the in-menu chat dialog
 			// This works around our inability to disable the sounds for the in-game dialog when it is hidden
--- a/OpenRA.Mods.Common/Widgets/Logic/Ingame/IngameMenuLogic.cs
+++ b/OpenRA.Mods.Common/Widgets/Logic/Ingame/IngameMenuLogic.cs
@@ -64,8 +64,7 @@ namespace OpenRA.Mods.Common.Widgets.Logic

 			menu = widget.Get("INGAME_MENU");
 			mpe = world.WorldActor.TraitOrDefault<MenuPaletteEffect>();
-			if (mpe != null)
-				mpe.Fade(mpe.Info.MenuEffect);
+			mpe?.Fade(mpe.Info.MenuEffect);

 			menu.Get<LabelWidget>("VERSION_LABEL").Text = modData.Manifest.Metadata.Version;

@@ -158,8 +157,7 @@ namespace OpenRA.Mods.Common.Widgets.Logic
 		void CloseMenu()
 		{
 			Ui.CloseWindow();
-			if (mpe != null)
-				mpe.Fade(MenuPaletteEffect.EffectType.None);
+			mpe?.Fade(MenuPaletteEffect.EffectType.None);
 			onExit();
 		}

--- a/OpenRA.Mods.Common/Widgets/Logic/Installation/InstallFromDiscLogic.cs
+++ b/OpenRA.Mods.Common/Widgets/Logic/Installation/InstallFromDiscLogic.cs
@@ -317,8 +317,7 @@ namespace OpenRA.Mods.Common.Widgets.Logic
 				output.Write(buffer, 0, write);
 				copied += write;

-				if (onProgress != null)
-					onProgress(copied);
+				onProgress?.Invoke(copied);
 			}
 		}

@@ -375,15 +374,7 @@ namespace OpenRA.Mods.Common.Widgets.Logic
 					{
 						Log.Write("install", "Extracting {0} -> {1}".F(sourcePath, targetPath));
 						if (type == ExtractionType.Blast)
-						{
-							Action<long, long> onBlastProgress = (read, _) =>
-							{
-								if (onProgress != null)
-									onProgress(read);
-							};
-
-							Blast.Decompress(source, target, onBlastProgress);
-						}
+							Blast.Decompress(source, target, (read, _) => onProgress?.Invoke(read));
 						else
 							CopyStream(source, target, length, onProgress);
 					}
--- a/OpenRA.Mods.Common/Widgets/Logic/MapChooserLogic.cs
+++ b/OpenRA.Mods.Common/Widgets/Logic/MapChooserLogic.cs
@@ -330,8 +330,7 @@ namespace OpenRA.Mods.Common.Widgets.Logic
 				onConfirm: () =>
 				{
 					var newUid = DeleteMap(map);
-					if (after != null)
-						after(newUid);
+					after?.Invoke(newUid);
 				},
 				confirmText: "Delete",
 				onCancel: () => { });
@@ -345,8 +344,7 @@ namespace OpenRA.Mods.Common.Widgets.Logic
 				onConfirm: () =>
 				{
 					maps.Do(m => DeleteMap(m));
-					if (after != null)
-						after(Game.ModData.MapCache.ChooseInitialMap(null, Game.CosmeticRandom));
+					after?.Invoke(Game.ModData.MapCache.ChooseInitialMap(null, Game.CosmeticRandom));
 				},
 				confirmText: "Delete",
 				onCancel: () => { });
--- a/OpenRA.Mods.Common/Widgets/Logic/MissionBrowserLogic.cs
+++ b/OpenRA.Mods.Common/Widgets/Logic/MissionBrowserLogic.cs
@@ -350,8 +350,7 @@ namespace OpenRA.Mods.Common.Widgets.Logic
 				player.PlayThen(() =>
 				{
 					StopVideo(player);
-					if (onComplete != null)
-						onComplete();
+					onComplete?.Invoke();
 				});

 				// Mute other distracting sounds
--- a/OpenRA.Mods.Common/Widgets/Logic/ReplayBrowserLogic.cs
+++ b/OpenRA.Mods.Common/Widgets/Logic/ReplayBrowserLogic.cs
@@ -415,8 +415,7 @@ namespace OpenRA.Mods.Common.Widgets.Logic
 					onConfirm: () =>
 					{
 						DeleteReplay(r);
-						if (after != null)
-							after.Invoke();
+						after?.Invoke();
 					},
 					confirmText: "Delete",
 					onCancel: () => { });
--- a/OpenRA.Mods.Common/Widgets/Logic/ServerListLogic.cs
+++ b/OpenRA.Mods.Common/Widgets/Logic/ServerListLogic.cs
@@ -541,8 +541,7 @@ namespace OpenRA.Mods.Common.Widgets.Logic
 				foreach (var row in rows)
 					serverList.AddChild(row);

-				if (nextServerRow != null)
-					nextServerRow.OnClick();
+				nextServerRow?.OnClick();

 				playerCount = games.Sum(g => g.Players);
 			});
@@ -744,8 +743,7 @@ namespace OpenRA.Mods.Common.Widgets.Logic
 			if (disposing && !disposed)
 			{
 				disposed = true;
-				if (lanGameProbe != null)
-					lanGameProbe.Dispose();
+				lanGameProbe?.Dispose();
 			}

 			base.Dispose(disposing);