dont crash if pawns are added to a level without a grid

Author: larsjsol

Source/Navgrid/Classes/TurnComponent.h

@@ -19,7 +19,7 @@ class NAVGRID_API UTurnComponent : public UActorComponent
 virtual void BeginPlay() override;
 virtual void OnComponentDestroyed(bool bDestroyingHierarchy) override;
 
-ATurnManager *GetTurnManager() { return TurnManager; }
+ATurnManager *GetTurnManager();
 protected:
 UPROPERTY()
 ATurnManager *TurnManager;

Source/Navgrid/Private/GridMovementComponent.cpp

@@ -145,7 +145,10 @@ void UGridMovementComponent::StopMovementImmediately()
 ChangeMovementMode(EGridMovementMode::Stationary);
 MovementPhase = EGridMovementPhase::Done;
 Distance = 0;
-Spline->ClearSplinePoints();
+if (IsValid(Spline))
+{
+Spline->ClearSplinePoints();
+}
 }
 
 FTransform UGridMovementComponent::TransformFromPath(float DeltaTime)
@@ -254,15 +257,22 @@ void UGridMovementComponent::ConsiderUpdateCurrentTile()
 CurrentTile = Tile;
 
 ANavGridGameState *GameState = Cast<ANavGridGameState>(UGameplayStatics::GetGameState(GetOwner()));
-AGridPawn *GridPawn = Cast<AGridPawn>(GetOwner());
-GameState->OnPawnEnterTile().Broadcast(GridPawn, CurrentTile);
+if (IsValid(GameState))
+{
+AGridPawn *GridPawn = Cast<AGridPawn>(GetOwner());
+GameState->OnPawnEnterTile().Broadcast(GridPawn, CurrentTile);
+}
 }
 }
 }
 
 void UGridMovementComponent::GetTilesInRange(TArray<UNavTileComponent *> &OutTiles)
 {
-Grid->GetTilesInRange(Cast<AGridPawn>(GetOwner()), OutTiles);
+if (IsValid(Grid))
+{
+ConsiderUpdateCurrentTile();
+Grid->GetTilesInRange(Cast<AGridPawn>(GetOwner()), OutTiles);
+}
 }
 
 UNavTileComponent *UGridMovementComponent::GetTile()

Source/Navgrid/Private/GridPawn.cpp

@@ -60,13 +60,16 @@ void AGridPawn::BeginPlay()
 {
 Super::BeginPlay();
 
-ATurnManager *TurnManager = GetWorld()->GetGameState<ANavGridGameState>()->GetTurnManager();
-TurnManager->OnRoundStart().AddDynamic(this, &AGridPawn::OnRoundStart);
-TurnManager->OnTurnStart().AddDynamic(this, &AGridPawn::OnAnyTurnStart);
-TurnManager->OnTurnEnd().AddDynamic(this, &AGridPawn::OnAnyTurnEnd);
-TurnManager->OnTeamTurnStart().AddDynamic(this, &AGridPawn::OnAnyTeamTurnStart);
-TurnManager->OnTeamTurnEnd().AddDynamic(this, &AGridPawn::OnAnyTeamTurnEnd);
-TurnManager->OnReadyForInput().AddDynamic(this, &AGridPawn::OnAnyPawnReadyForInput);
+ATurnManager *TurnManager =TurnComponent->GetTurnManager();
+if (IsValid(TurnManager))
+{
+TurnManager->OnRoundStart().AddDynamic(this, &AGridPawn::OnRoundStart);
+TurnManager->OnTurnStart().AddDynamic(this, &AGridPawn::OnAnyTurnStart);
+TurnManager->OnTurnEnd().AddDynamic(this, &AGridPawn::OnAnyTurnEnd);
+TurnManager->OnTeamTurnStart().AddDynamic(this, &AGridPawn::OnAnyTeamTurnStart);
+TurnManager->OnTeamTurnEnd().AddDynamic(this, &AGridPawn::OnAnyTeamTurnEnd);
+TurnManager->OnReadyForInput().AddDynamic(this, &AGridPawn::OnAnyPawnReadyForInput);
+}
 
 SetGenericTeamId(TeamId);
 
@@ -93,14 +96,10 @@ void AGridPawn::OnConstruction(const FTransform & Transform)
 
 void AGridPawn::SetGenericTeamId(const FGenericTeamId & InTeamId)
 {
-ANavGridGameState *State = GetWorld()->GetGameState<ANavGridGameState>();
-ATurnManager *NewTM = State->GetTurnManager();
-if (IsValid(NewTM))
-{
-NewTM->RegisterTurnComponent(TurnComponent);
-}
-
+// we must unregister before we change the team id
+TurnComponent->UnregisterWithTurnManager();
 TeamId = InTeamId;
+TurnComponent->RegisterWithTurnManager();
 }
 
 void AGridPawn::OnAnyTurnStart(UTurnComponent *InTurnComponent)
@@ -113,7 +112,6 @@ void AGridPawn::OnAnyTurnStart(UTurnComponent *InTurnComponent)
 
 void AGridPawn::OnTurnStart()
 {
-MovementComponent->ConsiderUpdateCurrentTile();
 if (SnapToGrid)
 {
 MovementComponent->SnapToGrid();

Source/Navgrid/Private/TurnComponent.cpp

@@ -23,6 +23,15 @@ void UTurnComponent::OnComponentDestroyed(bool bDestroyingHierarchy)
 UnregisterWithTurnManager();
 }
 
+ATurnManager * UTurnComponent::GetTurnManager()
+{
+if (!IsValid(TurnManager))
+{
+RegisterWithTurnManager();
+}
+return TurnManager;
+}
+
 void UTurnComponent::EndTurn()
 {
 if (IsValid(TurnManager))
@@ -86,8 +95,12 @@ AActor *UTurnComponent::GetCurrentActor() const
 void UTurnComponent::RegisterWithTurnManager()
 {
 UnregisterWithTurnManager();
-TurnManager = GetWorld()->GetGameState<ANavGridGameState>()->GetTurnManager();
-TurnManager->RegisterTurnComponent(this);
+ANavGridGameState *GameState = GetWorld()->GetGameState<ANavGridGameState>();
+if (IsValid(GameState))
+{
+TurnManager = GameState->GetTurnManager();
+TurnManager->RegisterTurnComponent(this);
+}
 }
 
 void UTurnComponent::UnregisterWithTurnManager()

Source/Navgrid/Private/TurnManager.cpp

@@ -82,11 +82,13 @@ void ATurnManager::Tick(float DeltaTime)
 
 void ATurnManager::RegisterTurnComponent(UTurnComponent *TurnComponent)
 {
+UE_LOG(NavGrid, Verbose, TEXT("%s (team %i) registering"), *TurnComponent->GetName(), TurnComponent->TeamId().GetId());
 Teams.AddUnique(TurnComponent->TeamId(), TurnComponent);
 }
 
 void ATurnManager::UnregisterTurnComponent(UTurnComponent * TurnComponent)
 {
+UE_LOG(NavGrid, Verbose, TEXT("%s (team %i) unregistering"), *TurnComponent->GetName(), TurnComponent->TeamId().GetId());
 Teams.RemoveSingle(TurnComponent->TeamId(), TurnComponent);
 if (CurrentComponent == TurnComponent)
 {