自定义CCNode

对Touch事件的获取与处理可以使用CCLayer, CCMenuItem等，但是如果我们需要一个虚拟按键或者需要对特定精灵进行拖动等等，我们就需要自定义Touch类。

自定义Touch事件处理类重要的步骤是：

1. 继承CCTargetedTouchDelegate

2. 添加addTargetedDelegate(pDelegate, nPriority, bSwallowsTouches)，来获取Touch事件，第二个参数是优先级，越高越优先。

3. 根据自己的需要override Touch事件处理函数：

virtual bool ccTouchBegan(CCTouch* touch, CCEvent* event);
virtual void ccTouchMoved(CCTouch *pTouch, CCEvent *pEvent);
virtual void ccTouchEnded(CCTouch *pTouch, CCEvent *pEvent);

如下是实例：这里添加一个自定义的Button到场景层。

#include <cocos2d.h>

USING_NS_CC;

class MyButton : public CCNode, public CCTargetedTouchDelegate
{
public:
    MyButton(void);
    ~MyButton(void);

    virtual void onEnter();
    virtual void onExit();

    virtual bool ccTouchBegan(CCTouch* touch, CCEvent* event);
    virtual void ccTouchMoved(CCTouch *pTouch, CCEvent *pEvent);
    virtual void ccTouchEnded(CCTouch *pTouch, CCEvent *pEvent);

    virtual bool init();
    CREATE_FUNC(MyButton);

private:
    CCSprite *m_ShowPic;
};

#include "MyButton.h"

MyButton::MyButton(void):m_ShowPic(NULL)
{
}

MyButton::~MyButton(void)
{
}

bool MyButton::init()
{
    bool bRet = false;
    do
    {
        CCSize winSize = CCDirector::sharedDirector()->getWinSize();

        m_ShowPic = CCSprite::create("share.png");
        m_ShowPic->setPosition(ccp(winSize.width/2, winSize.height/2));
        this->addChild(m_ShowPic);

        bRet = true;
    } while(0);
    return bRet;
}

void MyButton::onEnter()
{
    CCDirector::sharedDirector()->getTouchDispatcher()->addTargetedDelegate(this, 0, true);
    CCNode::onEnter();
}

void MyButton::onExit()
{
    CCDirector::sharedDirector()->getTouchDispatcher()->removeDelegate(this);
    CCNode::onExit();
}

bool MyButton::ccTouchBegan(CCTouch* touch, CCEvent* event)
{
    CCLog("MyButton Touch Began!");

    return true;
}

void MyButton::ccTouchMoved(CCTouch *pTouch, CCEvent *pEvent)
{
    CCLog("MyButton Touch Move!");
}

void MyButton::ccTouchEnded(CCTouch *pTouch, CCEvent *pEvent)
{
    CCLog("MyButton Touch Ended!");
}

将以下代码其添加到HelloWorldScene::init中，

////////////////////////////
// Add MyButton
MyButton *button = MyButton::create();
this->addChild(button, 10);
button->setPosition(CCPointZero);

运行测试：

在屏幕中点击可以看到Output中显示了我们的CCLog提示

可是我们没有点击到图片时也会提示出CCLog,这并不是我们想要的。

那么我们就需要添加自己需要的Touch事件处理代码了：

例如如下：

bool MyButton::ccTouchBegan(CCTouch* touch, CCEvent* event)
{
    CCPoint position = convertTouchToNodeSpaceAR(touch);
    if (!m_ShowPic->boundingBox().containsPoint(position))
        return false;
    CCLog("MyButton Touch Began!");
    // add your code...

    return true;
}

void MyButton::ccTouchMoved(CCTouch *pTouch, CCEvent *pEvent)
{
    CCLog("MyButton Touch Move!");
    // add your code...
}

void MyButton::ccTouchEnded(CCTouch *pTouch, CCEvent *pEvent)
{
    CCLog("MyButton Touch Ended!");
    // add your code...
}