EventListener for buttons - c++

Question

I'm developing a 2D car game using Cocos2d-x and I have a problem.
I want to use Box2D to make collisions and movement managing easier, but before that I want to get my 4 buttons working.
The point is that I have something like this
RaceScene.cpp
bool Race::init() {
//...
auto forwardArrow = MenuItemImage::create("forward_arrow.png", "forward_arrow.png", CC_CALLBACK_1(Race::forward, this));
forwardArrow->setAnchorPoint(Vec2(0,0));
forwardArrow->setPosition(Vec2(origin.x + visibleSize.width - forwardArrow->getContentSize().width*1.2 ,
origin.y + forwardArrow->getContentSize().height));
//...
}
void Race::forward(Ref* pSender)
{
/*MessageBox("YOU PRESSED THE FORWARD BUTTON","Alert");*/
}
But I've noticed this is not the way because I can't neither press more than 1 button at a time nor change speed according to the time the button is pressed.
So I've googled and checked Cocos documentation, and everybody talks about that EventListeners but I don't find how to add it to my problem.
I don't need to handle screen touches, I need to handle EACH button touch.
Thanks.

Answer 1

So, after some hours of researching and trying, as well as receiving some help from Cocos2d-x forums, I got the solution.
RaceScene.cpp
bool Race::init() {
...
forwardArrow = Sprite::create("forward_arrow.png");
forwardArrow->setAnchorPoint(Vec2(0,0));
forwardArrow->setPosition(Vec2(origin.x + visibleSize.width - forwardArrow->getContentSize().width*1.2 ,
origin.y + forwardArrow->getContentSize().height));
this->addChild(forwardArrow);
...
auto listenerForwardButton = EventListenerTouchOneByOne::create();
listenerForwardButton->setEnabled(true);
listenerForwardButton->setSwallowTouches(true);
listenerForwardButton->onTouchBegan = CC_CALLBACK_2(Race::onTouchesForwardBegan, this);
// trigger when you let up
listenerForwardButton->onTouchEnded = CC_CALLBACK_2(Race::onTouchesForwardEnded, this);
Director::getInstance()->getEventDispatcher()->addEventListenerWithSceneGraphPriority(listener, forwardArrow);
}
bool Race::onTouchesForwardBegan(cocos2d::Touch* touch, cocos2d::Event* event)
{
Vec2 touchPoint = touch->getLocation();
Rect boundingBoxArrow = this->forwardArrow->getBoundingBox();
if (boundingBoxArrow.containsPoint(touchPoint)){
return true;
}
return false;
}
void Race::onTouchesForwardEnded(cocos2d::Touch* touch, cocos2d::Event* event)
{
cocos2d::log("You touched %f, %f", touch->getLocationInView().x, touch->getLocationInView().y);
MessageBox("YOU PRESSED THE FORWARD BUTTON","Alert");
auto forward = MoveBy::create(1,Vec2(-5,0));
mainSprite->runAction(forward);
}
RaceScene.h
class Race : public cocos2d::Layer {
public:
virtual bool init();
cocos2d::Sprite* forwardArrow;
...
private:
bool onTouchesForwardBegan(cocos2d::Touch* touch, cocos2d::Event* event);
void onTouchesForwardEnded(cocos2d::Touch* touch, cocos2d::Event* event);
...
};
Please note that you need a listener->onTouchBegan which CC_CALLBACK_X redirects to a bool function. When this one returns true, then the onTouchEnd function works, it doesn't when this one returns false.
Hope it helps someone.