Add delegate for when state machine transitions to new state

Source/UnrealFightingFramework/Input/FFInputBufferComponent.cpp

@@ -16,6 +16,13 @@ void UFFInputBufferComponent::AddInput(const FFFInputState& InputState)
 
 bool UFFInputBufferComponent::CheckInputSequence(const FFFInputSequence& InputSequence)
 {
+    if(InputSequence.Sequence.IsEmpty())
+    {
+        UE_LOG(LogTemp, Error, 
+            TEXT("FFInputBufferComponent :: CheckInputSequence - tried to check input sequence but it was empty"));
+        return false;
+    }
+
     int CondIdx = InputSequence.Sequence.Num() - 1;
     int ElapsedFrames = 0;
     for(int InpIdx = InputBuffer.Num() - 1; InpIdx > 1; InpIdx--)

Source/UnrealFightingFramework/State/FFStateMachineComponent.cpp

@@ -115,12 +115,14 @@ void UFFStateMachineComponent::GoToState(UFFState* NewState)
         }
     }
 
+
     CurrentState->Exit(GetCurrentStateContext());
-    CurrentState = NewState;
     TicksInState = 0;
     TickStateWasEntered = GetWorld()->GetGameState<AFFGameState>()->GetCurrentTick();
     CurrentSubStateLabel = NAME_None;
-    CurrentState->Enter(GetCurrentStateContext());
+    NewState->Enter(GetCurrentStateContext());
+    OnStateTransition.Broadcast(CurrentState, NewState);
+    CurrentState = NewState;
 }
 
 void UFFStateMachineComponent::GoToEntryState()
@@ -251,6 +253,11 @@ void UFFStateMachineComponent::TickComponent(float DeltaTime, ELevelTick TickTyp
 		SMDebugString.Append(FString::Printf(TEXT("Current State: %s\n"), *CurrentState->Name.ToString()));
 		SMDebugString.Append(FString::Printf(TEXT("Current SubState Label: %s\n"), *CurrentSubStateLabel.ToString()));
 		SMDebugString.Append(FString::Printf(TEXT("Ticks In State: %lld\n"), TicksInState));
+        SMDebugString.Append(FString::Printf(TEXT("-- States added --\n")));
+        for (auto TempState : States)
+        {
+            SMDebugString.Append(FString::Printf(TEXT("%s\n"), *TempState->Name.ToString()));
+        }
 
         GEngine->AddOnScreenDebugMessage(-1, 0.0f, FColor::Green, SMDebugString);
     }

Source/UnrealFightingFramework/State/FFStateMachineComponent.h

@@ -12,6 +12,9 @@
 
 #include "FFStateMachineComponent.generated.h"
 
+DECLARE_DYNAMIC_MULTICAST_DELEGATE_TwoParams(FOnStateTransitionSignature, 
+    const UFFState*, PrevState, const UFFState*, NextState);
+
 /**
  *	A state machine is a component that evaluates and controls the transitions for state objects that
  *	are a part of this state machine.
@@ -48,6 +51,9 @@ public:
 	 *
 	 *	@return A pointer to the state that was added or nullptr if there was an issue adding or creating the state
 	 */
+	// TODO: return should probably be a const pointer if this function is public. I don't want
+	// anything outside of the state machine modifying the state. Really, I want states in general to
+	// be read only objects that are only modified at edit time when creating state blueprints.
 	UFFState* AddState(TSubclassOf<UFFState> StateClassToAdd);
 
     /**
@@ -92,12 +98,18 @@ public:
 	UFUNCTION(BlueprintPure)
 	FORCEINLINE int64 GetTickStateWasEntered() const { return TickStateWasEntered; }
 
+	UFUNCTION(BlueprintPure)
+	const UFFState* GetCurrentState() const { return const_cast<UFFState*>(CurrentState); }
+
     /**
      *	Returns the name of the current state
      */
 	UFUNCTION(BlueprintPure)
 	FORCEINLINE FName GetCurrentStateName() const;
 
+    /**
+     *	Returns the name of the current sub state label
+     */
 	UFUNCTION(BlueprintPure)
 	FORCEINLINE FName GetCurrentSubStateLabel() const { return CurrentSubStateLabel; }
 
@@ -115,6 +127,8 @@ public:
 	virtual void MovementModeChanged(EMovementMode PrevMovementMode, uint8 PreviousCustomMode, 
 	    EMovementMode NewMovementMode, uint8 NewCustomMode);
 
+	FOnStateTransitionSignature OnStateTransition;
+
 	// IFFSystemInterface interface
     virtual void FixedTick(float OneFrame) override;
 	// End of IFFSystemInterface interface