cocos2d - collision callback doesn't invoke - cocos2d-iphone

Question

I'am trying to build a simple game with a ball and target,
and I want to increse the score when the ball touch the target,
but the callback "onContactBegin" doesnt invoke.
There is a target("goal") in the button of the screen, and when the user touch the screen the ball created and start moving.
#include <string>
#include "HelloWorldScene.h"
#define COCOS2D_DEBUG 1
USING_NS_CC;
enum class PhysicsCategory {
None = 0,
Goal = (1 << 0),
Ball = (1 << 1),
All = PhysicsCategory::Goal | PhysicsCategory::Ball
};
Scene* HelloWorld::createScene()
{
auto scene = Scene::create();
auto layer = HelloWorld::create();
scene->addChild(layer);
return scene;
}
bool HelloWorld::init()
{
CCLOG("Init");
if ( !Layer::init() )
{
return false;
}
Size visibleSize = Director::getInstance()->getVisibleSize();
Point origin = Director::getInstance()->getVisibleOrigin();
height = visibleSize.height;
width = visibleSize.width;
score = 0;
m_score_label = Label::createWithTTF(Itos(score), "fonts/Marker Felt.ttf", 24);
auto vSize = Director::getInstance()->getVisibleSize();
m_score_label->setPosition(Point(origin.x + vSize.width/2,
origin.y + vSize.height - m_score_label->getContentSize().height));
this->addChild(m_score_label, 1);
goal = Sprite::create("images.jpg");
goal->setPosition(Point((visibleSize.width / 2) + origin.x , (visibleSize.height / 6) + origin.y));
auto goalSize = goal->getContentSize();
auto physicsBody = PhysicsBody::createBox(Size(goalSize.width , goalSize.height),
PhysicsMaterial(0.1f, 1.0f, 0.0f));
physicsBody->setCategoryBitmask((int)PhysicsCategory::Goal);
physicsBody->setCollisionBitmask((int)PhysicsCategory::None);
physicsBody->setContactTestBitmask((int)PhysicsCategory::Ball);
goal->setPhysicsBody(physicsBody);
mySprite = Sprite::create("CloseNormal.png");
mySprite->setPosition(Point((visibleSize.width / 2) + origin.x , (visibleSize.height / 2) + origin.y));
this->addChild(mySprite);
this->addChild(goal);
CCScaleBy* action = CCScaleBy::create(3,5);
mySprite->runAction(action);
auto eventListener = EventListenerTouchOneByOne::create();
eventListener->onTouchBegan = CC_CALLBACK_2(HelloWorld::onTouchBegan, this);
this->getEventDispatcher()->addEventListenerWithSceneGraphPriority(eventListener, this);
auto contactListener = EventListenerPhysicsContact::create();
contactListener->onContactBegin = CC_CALLBACK_1(HelloWorld::onContactBegan, this);
this->getEventDispatcher()->addEventListenerWithSceneGraphPriority(contactListener, this);
return true;
}
bool HelloWorld::onTouchBegan(Touch *touch, Event *unused_event) {
cocos2d::Sprite * sp = Sprite::create("CloseNormal.png");
sp->setPosition(Point(touch->getLocation().x , touch->getLocation().y));
MoveTo *action = MoveTo::create(2, Point(width ,0) );
auto ballSize = sp->getContentSize();
auto physicsBody = PhysicsBody::createBox(Size(ballSize.width , ballSize.height),
PhysicsMaterial(0.1f, 1.0f, 0.0f));
physicsBody->setDynamic(true);
physicsBody->setCategoryBitmask((int)PhysicsCategory::Ball);
physicsBody->setCollisionBitmask((int)PhysicsCategory::None);
physicsBody->setContactTestBitmask((int)PhysicsCategory::Goal);
sp->setPhysicsBody(physicsBody);
sp->runAction( action );
this->addChild(sp);
return true;
}
void HelloWorld::menuCloseCallback(Ref* pSender)
{
#if (CC_TARGET_PLATFORM == CC_PLATFORM_WP8) || (CC_TARGET_PLATFORM == CC_PLATFORM_WINRT)
MessageBox("You pressed the close button. Windows Store Apps do not implement a close button.","Alert");
return;
#endif
Director::getInstance()->end();
#if (CC_TARGET_PLATFORM == CC_PLATFORM_IOS)
exit(0);
#endif
}
bool HelloWorld::onContactBegan(PhysicsContact &contact)
{
CCLOG("onContactBegan");
auto nodeA = contact.getShapeA()->getBody()->getNode();
auto nodeB = contact.getShapeB()->getBody()->getNode();
nodeA->removeFromParent();
nodeB->removeFromParent();
++score ;
m_score_label->setString(Itos(score));
return true;
}
std::string HelloWorld::Itos ( int num )
{
std::ostringstream ss;
ss << num;
return ss.str();
}

Answer 1

HelloWorld.cpp
Scene* HelloWorld::createScene() {
auto scene = Scene::createWithPhysics();
auto layer = HelloWorld::create();
layer->setPhysicsWorld(scene->getPhysicsWorld());
scene->getPhysicsWorld()->setDebugDrawMask(PhysicsWorld::DEBUGDRAW_ALL);
scene->addChild(layer);
return scene;
}
bool GameScene::didBeginContact(cocos2d::PhysicsContact &contact) {
PhysicsBody *bodyA = contact.getShapeA()->getBody();
PhysicsBody *bodyB = contact.getShapeB()->getBody();
}
HelloWorld.h
cocos2d::PhysicsWorld *physicsWorld;
void setPhysicsWorld(cocos2d::PhysicsWorld *withWorld) {physicsWorld = withWorld;};
bool didBeginContact(cocos2d::PhysicsContact &contact);