cocos2dx --- Touch （一）

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1.相关的类

　　CCTouch:封装了触摸点。通过getLocation()返回OpenGL coordinates下的CCpoint，或通通过getLocationInView()返回在Screen coordinates下的CCpoint

CCTouchDelegate:触摸事件委托。在处理触摸事件时，必须继承该类。它封装了如下几个方法

1 virtual void ccTouchesBegan(CCSet *pTouches, CCEvent *pEvent);
2 virtual void ccTouchesMoved(CCSet *pTouches, CCEvent *pEvent);
3 virtual void ccTouchesEnded(CCSet *pTouches, CCEvent *pEvent);
4 virtual void ccTouchesCancelled(CCSet *pTouches, CCEvent *pEvent);
5  
6 virtual bool ccTouchBegan(CCTouch *pTouch, CCEvent *pEvent);
7 virtual void ccTouchMoved(CCTouch *pTouch, CCEvent *pEvent);
8 virtual void ccTouchEnded(CCTouch *pTouch, CCEvent *pEvent);
9 virtual void ccTouchCancelled(CCTouch *pTouch, CCEvent *pEvent);

CCTargetTouchDelegate和CCStandardTouchDelegate作为CCTouchDelegate的派生类，分别用于处理多点触摸和单点触摸事件。

CCTouchHandler：封装了CCTouchDelegate和其对应的优先级，优先级越高，分发的事件越容易获得事件的处理权限，CCTouchHandler派生出了CCStandardTouchHandler和CCTargetTouchHandler。

2.执行流程

在自定义的类中，继承CCTouchDelegate，重写触屏事件处理函数和registerWithTouchDispatcher方法，并在init或onEnter方法中调用registerWithTouchDispatcher。代码如下：

1 void XXXLayer::registerWithTouchDispatcher()
2 {
3     cocos2d::CCTouchDispatcher::sharedDispatcher()->addTargetedDelegate(this, 0, true);
4    //CCDirector::sharedDirector()->getTouchDispatcher()->addStandardDelegate(this,0);
5 }

将相应的CCTouchDelegate添加到CCTouchDispatcher的分发列表中。addXXXDelegate方法创建CCTouchDelegate对应的CCTouchHandler对象并添加到CCMutableArray中。源码：

 1 void CCTouchDispatcher::addStandardDelegate(CCTouchDelegate *pDelegate, int nPriority)
 2 {    
 3     CCTouchHandler *pHandler = CCStandardTouchHandler::handlerWithDelegate(pDelegate, nPriority);
 4     if (! m_bLocked)
 5     {
 6         forceAddHandler(pHandler, m_pStandardHandlers);
 7     }
 8     else
 9     {
13         if (ccCArrayContainsValue(m_pHandlersToRemove, pDelegate))
14         {
15             ccCArrayRemoveValue(m_pHandlersToRemove, pDelegate);
16             return;
17         }
18 
19         m_pHandlersToAdd->addObject(pHandler);
20         m_bToAdd = true;
21     }
22 }
23 void CCTouchDispatcher::forceAddHandler(CCTouchHandler *pHandler, CCArray *pArray)
24 {
25     unsigned int u = 0;
26 
27     CCObject* pObj = NULL;
28     CCARRAY_FOREACH(pArray, pObj)
29      {
30          CCTouchHandler *h = (CCTouchHandler *)pObj;
31          if (h)
32          {
33              if (h->getPriority() < pHandler->getPriority())
34              {
35                  ++u;
36              }
37  
38              if (h->getDelegate() == pHandler->getDelegate())
39              {
40                  CCAssert(0, "");
41                  return;
42              }
43          }
44      }
45 
46     pArray->insertObject(pHandler, u);
47 }

事件分发时就是从m_pStandardHandlers取出CCStandardTouchHandler，然后调用handler对应的delegate。CCTouchDispatcher继承了纯虚类EGLTouchDelegate，并实现

1     virtual void touchesBegan(CCSet* touches, CCEvent* pEvent) = 0;
2     virtual void touchesMoved(CCSet* touches, CCEvent* pEvent) = 0;
3     virtual void touchesEnded(CCSet* touches, CCEvent* pEvent) = 0;
4     virtual void touchesCancelled(CCSet* touches, CCEvent* pEvent) = 0;

这四个方法。这四个函数调用touches方法。

posted on 2013-05-03 17:27 chchpd 阅读(840) 评论(0) 收藏举报

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