Player turn on/off lamp using button.

Development Programming & Scripting C++
1

Hello everyone,

I have two my own classes which i created (Lamp and Button) and a default Character class. In the Character class I created Use method which is binding to the E keyboard. In the Lamp class I created ToggleLight method wchich turn on and turn off light. Finally in the Button class I created OnOverlapBegin and OnOverLapEnd methods:


void AOnOffButton::OnOverlapBegin(class UPrimitiveComponent* OverlappedComp, class AActor* OtherActor, class UPrimitiveComponent* OtherComp,
	int32 OtherBodyIndex, bool bFromSweep, const FHitResult& SweepResult)
{
	GEngine->AddOnScreenDebugMessage(1, 5.f, FColor::Red, TEXT("Press E"));
}

void AOnOffButton::OnOverlapEnd(class UPrimitiveComponent* OverlappedComp, class AActor* OtherActor, class UPrimitiveComponent* OtherComp,
	int32 OtherBodyIndex)
{
	GEngine->AddOnScreenDebugMessage(1, 5.f, FColor::Red, TEXT(" "));
}

Now i would like to make possibility that this Character can turn on or turn off light using button but I have no idea how to do that becouse I don’t know how to using another objects in another classes. I think that I should make any pointer to another object but I need any example how to do that.

2

I wouldn’t necessarily do it with OnOverlapBegin. I would implement OnUse function on the button.

Then on the Character Use function I would do something like this:



float flBest = 100.0f;
class AOnOFfButton *pBest = NULL;

for (TActorIterator<AOnOFfButton> ButtonItr(GetWorld()); ButtonItr; ++ButtonItr)
{
	class AOnOFfButton *pButton = *ButtonItr;

	float flDist = FVector::Dist(pButton->GetActorLocation(), GetActorLocation());
	if (flDist < flBest)
	{
		flBest = flDist;
		pBest = pButton;
	}
}

if (pBest)
{
	pBest->OnUse();
}

In the button I would define the target that it wants to toggle on and off. You could make a base class for the lamp (for example I have AItemBase class that is the base for all interactive objects in the game) and give it a virtual OnUsed() function. But in your case right now you can just add this to your buttons header:



private:
	UPROPERTY(EditInstanceOnly, BlueprintReadOnly, meta = (AllowPrivateAccess = "true"))
	ALamp			*LampTarget;

This will allow you to edit LampTarget in the Details panel when selecting the button in the level editor.

Then in your button’s OnUse()




void AOnOFfButton::OnUse()
{
	if (LampTarget)
		LampTarget->ToggleLight();
}
3

Thanks a lot! It works. My problem was that I didn’t know that I can set ObjectTarget in level editor :smiley: And first time I see this function (TActorIterator<AOnOFfButton> ButtonItr(GetWorld()); ButtonItr; ++ButtonItr) it will be very useful for another projects :slight_smile: