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ULCKBaseButton

Base class for all UI button components providing touch interaction, visual state management, and event delegation.

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Properties

PropertyTypeDescription
ButtonTypeELCKButtonTypeButton shape type
CollisionBoxUBoxComponent*Touch collision detection
ButtonSmcUStaticMeshComponent*Visual mesh
ButtonLabelUTextRenderComponent*Text label
ButtonNameFNameIdentifier
PressedOffsetFVectorVisual offset when pressed

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Events

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OnTapStarted
FOnTapStarted
Broadcast when button is tapped.
DECLARE_DYNAMIC_MULTICAST_DELEGATE(FOnTapStarted);

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Methods

MethodDescription
ButtonPressed(TapData)Handle press input
ButtonReleased(TapData)Handle release input
UpdateVisualsOnPressed()Set pressed visual state
UpdateVisualsOnReleased()Set released visual state
Show()Make visible
Hide()Make hidden
SetUVOffset(UVOffset)Set primary UV offset
SetSecondUVOffset(UVOffset)Set secondary UV offset

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Example

ULCKBaseButton* Button = CreateDefaultSubobject<ULCKBaseButton>(TEXT("ActionButton"));
Button->SetupAttachment(RootComponent);
Button->ButtonName = TEXT("MyAction");

Button->OnTapStarted.AddDynamic(this, &AMyActor::HandleButtonTap);

void AMyActor::HandleButtonTap()
{
    UE_LOG(LogTemp, Log, TEXT("Button tapped!"));
}

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ULCKToggle

Toggle button with on/off states and state-dependent icons.

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Properties

PropertyTypeDescription
ToggleOnIconUTexture2D*Icon for on state
ToggleOffIconUTexture2D*Icon for off state

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Methods

MethodDescription
UpdateVisuals(bIsOn)Update appearance based on state

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Derived Classes

Microphone toggle button with mute/unmute icons.
Camera follow mode toggle for selfie camera.
Landscape/portrait orientation toggle.
Rectangle-shaped toggle button.

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Example

ULCKToggle* MicToggle = CreateDefaultSubobject<ULCKToggle>(TEXT("MicToggle"));
MicToggle->ToggleOnIcon = MicOnTexture;
MicToggle->ToggleOffIcon = MicOffTexture;

MicToggle->OnTapStarted.AddDynamic(this, &AMyActor::OnMicToggled);

void AMyActor::OnMicToggled()
{
    bMicEnabled = !bMicEnabled;
    MicToggle->UpdateVisuals(bMicEnabled);
    Service->SetMicrophoneEnabled(bMicEnabled);
}

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ULCKRectButton

Rectangle-shaped button for text labels and actions.

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Derived Classes

Camera flip/mirror toggle button.

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ULCKRecordButton

Record button with time display and recording state visualization.

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Interfaces

Implements ILCKRecordable.

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Events

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OnRecordButtonPressed
FOnRecordButtonPressed
Broadcast when record button is pressed.
DECLARE_MULTICAST_DELEGATE_OneParam(FOnRecordButtonPressed, ILCKRecordable*);

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Methods

MethodDescription
SetTime(NewTime)Update displayed recording time
UpdateVisuals(NewState)Update for recording state

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Example

ULCKRecordButton* RecordButton = CreateDefaultSubobject<ULCKRecordButton>(TEXT("RecordButton"));

RecordButton->OnRecordButtonPressed.AddLambda([this](ILCKRecordable* Recordable) {
    if (Service->IsRecording())
    {
        Service->StopRecording();
        Recordable->UpdateVisuals(ELCKRecordingState::Saving);
    }
    else
    {
        Service->StartRecording();
        Recordable->UpdateVisuals(ELCKRecordingState::Recording);
    }
});

// Update time display during recording
void AMyActor::Tick(float DeltaTime)
{
    if (Service->IsRecording())
    {
        RecordButton->SetTime(Service->GetCurrentRecordingDuration());
    }
}

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ULCKVideoQualityButton

Video quality selection button cycling through SD, HD, 2K, 4K presets.

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ULCKOnScreenButton

Button rendered on the display surface for in-viewport interaction.

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Derived Classes

Flip button on display surface.
Photo capture button on display surface.

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Touch Interaction

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Enabling Interactions

Interaction with the UI is collision-based. The simplest way to enable interactions is to add a SphereCollider with 5-10mm radius to the index fingertip. Finger collider setup Make sure that the collider has the UICollision tag. It’s used to filter collision for UI. UICollision tag

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FLCKTapData

Touch event data structure. 
USTRUCT()
struct LCKUI_API FLCKTapData
{
    FVector ButtonLocation;      // World position of button
    FVector ButtonRightVector;   // Button's right vector
    FVector ButtonForwardVector; // Button's forward vector
    FVector TapLocation;         // World position of tap
    bool IsPressed;              // Currently pressed state
};

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Interaction Direction

Configure which direction validates touch input: 
UENUM(BlueprintType)
enum class ELCKButtonInteractionDirection : uint8
{
    Forward,  // Touch must come from front
    Up        // Touch must come from above
};

Button->SetButtonInteractionDirection(ELCKButtonInteractionDirection::Forward);

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Cooldown

Buttons have a built-in 0.25s cooldown to prevent accidental double-taps. This is handled automatically by FLCKConstants::CoolDownTime.
Don’t add additional cooldown logic in your code - the SDK handles this automatically.