Creating Timelines

Creating Timelines

You can create and instantiate your own Timeline Component in an Actor class by following the steps below.

1. Navigate to your C++ Classes folder and click the Add+. From the drop down menu select New C++ Class.

   

2. Select Actor class as a Parent Class.

   

3. Name created Actor class Timeline Actor.

   

4. Navigate to your TimelineActor.h file and include following TimelineComponent class library.

   TimelineActor.h

   C++

   #include "Components/TimelineComponent.h"

   Copy full snippet(1 line long)

5. Implement the following class declaration inside the TimelineActor class defintion:

   TimelineActor.h

   C++

   protected:
   
           UPROPERTY(EditAnywhere, BlueprintReadWrite)
           UTimelineComponent* ExampleTimelineComp;

   Copy full snippet(4 lines long)

   In this code sample, you use the Property Specifier Tags, EditAnywhere, and BlueprintReadWrite.

6. Navigate to the TimelineActor.cpp file, then add the following code to your TimelineActor constructor ATimelineActor::ATimelineActor()

   TimelineActor.cpp

   C++

   ATimelineActor::ATimelineActor()
        {
            // Set this actor to call Tick() every frame.  You can turn this off to improve performance if you don't need it.
            PrimaryActorTick.bCanEverTick = true;
            ExampleTimelineComp = CreateDefaultSubobject<UTimelineComponent>(TEXT("TimelineComponent"));
        }

   Copy full snippet(6 lines long)

7. Compile your code.

8. Navigate to the C++ classes folder, right-click on your TimelineActor and create a Blueprint based on your TimelineActor class. Name it Bp_TimelineActor.

   

9. Once you have created your TimelineActor Blueprint, you can view the Class Defaults. From the Components tab, you should see your example Timeline Component.

   

Work-In-Progress Code

TimelineActor.h

#pragma once
	#include "Components/TimelineComponent.h"
	#include "CoreMinimal.h"
	#include "GameFramework/Actor.h"
	#include "TimelineActor.generated.h"

	UCLASS()
	class CPPTIMELINE_API ATimelineActor : public AActor
	{
		GENERATED_BODY()

TimelineActor.cpp

#include "TimelineActor.h"

	// Sets default values
	ATimelineActor::ATimelineActor()
	{
		// Set this actor to call Tick() every frame.  You can turn this off to improve performance if you don't need it.
		PrimaryActorTick.bCanEverTick = true;
		ExampleTimelineComp = CreateDefaultSubobject<UTimelineComponent>(TEXT("TimelineComponent"));
	}

Timeline Variables

When you create a Timeline Component in C++ using UProperty Specifiers, it will become available as a variable in your Components tab. This may be useful for designers who would like to continue to make iterations to your TimelineComponent via Blueprint Scripting.

For a complete list of the available Blueprint Timeline nodes and their functionality please see the Timeline nodes page.

Creating a FTimeLineEvent

Timeline Events (FOnTimelineEvent) are Dynamic Delegates that provide functionality to a Timeline Component to handle an Event. Follow the steps below to create your own FTimeLineEvent to be bound to your Timeline Component's finished functionality.

1. Navigate to TimelineActor.h file and declare the following code in the Class Definition:

   TimelineActor.h

   C++

   protected:
   
            //Delegate signature for the function which will handle our Finished event.
            FOnTimelineEvent TimelineFinishedEvent;
   
            UFUNCTION()
            void TimelineFinishedFunction();

   Copy full snippet(7 lines long)

2. Navigate to TimelineActor.cpp and implement the following code:

   TimelineActor.cpp

   C++

   void ATimelineActor::TimelineFinishedFunction()
         {
            UE_LOG(LogTemp, Warning, TEXT("Finished Event Called."));
         }

   Copy full snippet(4 lines long)

3. Navigate to ATimelineActor::BeginPlay() method, and implement the following code:

   TimelineActor.cpp

   C++

   // Called when the game starts or when spawned
   
        void ATimelineActor::BeginPlay()
        {
            Super::BeginPlay();
   
            TimelineFinishedEvent.BindUFunction(this, FName("TimelineFinishedFunction"));
            ExampleTimelineComp->SetTimelineFinishedFunc(TimelineFinishedEvent);
            ExampleTimelineComp->PlayFromStart();
        }

   Copy full snippet(10 lines long)

   You have now successfully bound your TimelineFinished Event to your custom TimelineFinished function.

4. Compile your code. Open Editor and navigate to the Content Browser. Find your BP_TimelineActor and drag off it into the Level.

   

5. Press Play button. You should see the following message in the Output Log window:

   

Finished Code

TimelineActor.h

#pragma once
	#include "Components/TimelineComponent.h"
	#include "CoreMinimal.h"
	#include "GameFramework/Actor.h"
	#include "TimelineActor.generated.h"

	UCLASS()
	class CPPTIMELINE_API ATimelineActor : public AActor
	{
		GENERATED_BODY()

TimelineActor.cpp

#include "TimelineActor.h"

	// Sets default values
	ATimelineActor::ATimelineActor()
	{
		// Set this actor to call Tick() every frame.  You can turn this off to improve performance if you don't need it.
		PrimaryActorTick.bCanEverTick = true;
		ExampleTimelineComp = CreateDefaultSubobject<UTimelineComponent>(TEXT("TimelineComponent"));
	}