cocos2d subclassing sprite to handle touch?

问题

I'm new to the cocos2d(-x) world.

I'd like to detect a touch to a sprite, and tutorials/examples seem to suggest using layer to detect touch and find the approapriate sprite with bounding box.

Is subclassing sprite to allow touch detection generally a bad idea?

回答1:

it is better and much more clear to handle touches in one place. but i think, no one can bar you to do this

回答2:

Note: This answer might be outdated. I answered this at 2012.

It is not a bad idea. Here is how I do it:

header file:

#include "cocos2d.h"
using namespace cocos2d;
class TouchableSprite : public cocos2d::CCSprite, public CCTargetedTouchDelegate {
    public:
    virtual void onEnter();
    virtual void onExit();
    virtual bool ccTouchBegan(CCTouch* touch, CCEvent* event);
    virtual void ccTouchMoved(CCTouch* touch, CCEvent* event);
    virtual void ccTouchEnded(CCTouch* touch, CCEvent* event);
};

cpp file:

#include "TouchableSprite.h"
void TouchableSprite::onEnter(){
    // before 2.0:
    // CCTouchDispatcher::sharedDispatcher()->addTargetedDelegate(this, 0, true);

    // since 2.0: 
    CCDirector::sharedDirector()->getTouchDispatcher()->addTargetedDelegate(this, 0, true);
    CCSprite::onEnter();
}
void TouchableSprite::onExit(){
    // before 2.0:
    // CCTouchDispatcher::sharedDispatcher()->removeDelegate(this);

    // since 2.0:
    CCDirector::sharedDirector()->getTouchDispatcher()->removeDelegate(this);
    CCSprite::onExit();
}
bool TouchableSprite::ccTouchBegan(CCTouch* touch, CCEvent* event){
    //do whatever you want here
    return true;
}
void TouchableSprite::ccTouchMoved(CCTouch* touch, CCEvent* event){
    //do what you want
}
void TouchableSprite::ccTouchEnded(CCTouch* touch, CCEvent* event){
    //do your job here
}

回答3:

In cocos2d-x 3.0 alpha you can try this:

auto listener = EventListenerTouchOneByOne::create();

listener->setSwallowTouches(true);

listener->onTouchBegan = [&](Touch* touch, Event* event){

    if (this->getBoundingBox().containsPoint(this->convertTouchToNodeSpace(touch))) {
        return true;
    }
    return false;

};

Director::getInstance()->getEventDispatcher()->addEventListenerWithSceneGraphPriority(listener, this);