[cocos2d-x 3.2]EventDispatcher事件分发机制
EventDispatcher事件分发机制先创建事件，注册到事件管理中心_eventDispatcher，通过发布事件得到响应进行回调，完成事件流。
有五种不同的事件机制：
EventListenerTouch 响应触控事件
EventListenerKeyboard 响应键盘事件
EventListenerAcceleration 响应加速器事件
EventListenMouse 响应鼠标事件
EventListenerCustom 响应自定义的事件
优先权：
1.优先级越低，越先响应事件
2.如果优先级相同，则上层的（z轴）先接收触摸事件。
事件监听器的优先级：
1.addEventListenerWithSceneGraphPriority 的事件监听器优先级是0，而且在 addEventListenerWithFixedPriority 中的事件监听器的优先级不可以设置为 0，因为这个是保留给 SceneGraphPriority 使用的。
2.另外，有一点非常重 要，FixedPriority listener添加完之后需要手动remove，而SceneGraphPriority listener是跟node绑定的，在node的析构函数中会被移除。移除方 法：dispatcher->removeEventListener(listener);
事件管理单例获取：
_eventDispatcher是Node的属性，通过它管理当前节点（场景、层、精灵等）的所有事件的分发。但它本身是一个单例模式值的引用，在 Node的构造函数中，通过Director::getInstance()->getEventDispatcher(); 获取，有了这个属性，就能方便的处理事件。
触摸事件：
void EventDispatcherTest::funEventTouch(Sprite* sprite)
{ this->_eventDispatcher->removeAllEventListeners();
auto listener = EventListenerTouchOneByOne::create();
listener->onTouchBegan = CC_CALLBACK_2(EventDispatcherTest::onTouchBeganss,this);
listener->onTouchMoved = CC_CALLBACK_2(EventDispatcherTest::onTouchMovedss,this);
listener->onTouchEnded = CC_CALLBACK_2(EventDispatcherTest::onTouchEndedss,this);
listener->onTouchCancelled = CC_CALLBACK_2(EventDispatcherTest::onTouchCancelledss,this);
listener->setSwallowTouches(true);//是否向下传递
this->_eventDispatcher->addEventListenerWithSceneGraphPriority(listener,sprite);
}bool EventDispatcherTest::onTouchBeganss(Touch* touch,Event* ev)
{
auto target = static_cast<Sprite*>(ev->getCurrentTarget());
Vec2 locationInNode = target->convertToNodeSpace(touch->getLocation());
Size s = target->getContentSize();
Rect rect = Rect(0, 0, s.width, s.height);
//判断触摸区域是否在目标上 if (rect.containsPoint(locationInNode))
{
label->setString("onTouchBegan......");
target->setOpacity(180); return true;
} return false;
}void EventDispatcherTest::onTouchMovedss(Touch* touch,Event* ev)
{
auto target = static_cast<Sprite*>(ev->getCurrentTarget());
target->setPosition(target->getPosition() + touch->getDelta());
label->setString("onTouchMoved......");
}void EventDispatcherTest::onTouchEndedss(Touch* touch,Event* ev)
{
auto target = static_cast<Sprite*>(ev->getCurrentTarget());
target->setOpacity(255);
label->setString("onTouchEnded......");
}void EventDispatcherTest::onTouchCancelledss(Touch* touch,Event* ev)
{
label->setString("onTouchCancelled......");
}
键盘事件
void EventDispatcherTest::funEventKeyboard()
{ this->_eventDispatcher->removeAllEventListeners();
auto listener = EventListenerKeyboard::create();
listener->onKeyPressed = CC_CALLBACK_2(EventDispatcherTest::onKeyPressedss,this);
listener->onKeyReleased = CC_CALLBACK_2(EventDispatcherTest::onKeyReleasedss,this); this->_eventDispatcher->addEventListenerWithSceneGraphPriority(listener,this);
}void EventDispatcherTest::onKeyPressedss(EventKeyboard::KeyCode keycode,Event* ev)
{ char txt[100] = {};
sprintf_s(txt,"key %d is Pressed!",(int)keycode);
label->setString(txt);
}void EventDispatcherTest::onKeyReleasedss(EventKeyboard::KeyCode keycode,Event* ev)
{
label->setString("key is Released!");
}
鼠标事件
void EventDispatcherTest::funEventMouse(Sprite* sprite)
{ this->_eventDispatcher->removeAllEventListeners();
auto listener = EventListenerMouse::create();
listener->onMouseDown = CC_CALLBACK_1(EventDispatcherTest::onMouseDownss,this);
listener->onMouseMove = CC_CALLBACK_1(EventDispatcherTest::onMouseMovess,this);
listener->onMouseUp = CC_CALLBACK_1(EventDispatcherTest::onMouseUpss,this);
listener->onMouseScroll = CC_CALLBACK_1(EventDispatcherTest::onMouseScrollss,this); this->_eventDispatcher->addEventListenerWithSceneGraphPriority(listener,sprite);
}void EventDispatcherTest::onMouseDownss(Event* ev)
{
label->setString("onMouseDown!");
}void EventDispatcherTest::onMouseMovess(Event* ev)
{
label->setString("onMouseMove!");
}void EventDispatcherTest::onMouseUpss(Event* ev)
{
label->setString("onMouseUp!");
}void EventDispatcherTest::onMouseScrollss(Event* ev)
{
label->setString("onMouseScroll!");
}
自定义事件
//自定�x事件 funEventCustom(); //2秒後派�l一次自定�x事件，�y� scheduleOnce(schedule_selector(EventDispatcherTest::dispatcherCustomEvents),2.0f);
void EventDispatcherTest::funEventCustom()
{
auto listener = EventListenerCustom::create("custom_event_1",CC_CALLBACK_1(EventDispatcherTest::onEventCustom,this)); this->_eventDispatcher->addEventListenerWithFixedPriority(listener,1);//添加到事件分�l器}void EventDispatcherTest::dispatcherCustomEvents(float at)
{ //派�l事件custom_event_1 事件�热�樽址�串custom event test!
this->_eventDispatcher->dispatchCustomEvent("custom_event_1","custom event test!");
}void EventDispatcherTest::onEventCustom(EventCustom* event)
{
auto data = static_cast<char*>(event->getUserData());
label->setString(data);
}
加速器事件
除了触摸，移动设备上一个很重要的输入源是设备的方向，因此大多数设备都配备了加速计，用于测量设备静止或匀速运动时所受到的重力方向。
重力感应来自移动设备的加速计，通常支持X,Y和Z三个方向的加速度感应，所以又称为三向加速计。在实际应用中，可以根据3个方向的力度大小来计算手机倾斜的角度或方向。
加速计监听器EventListenerAcceleration，其静态create方法中有个Acceleration的参数。Acceleration是一个类，包含了加速计获得的3个方向的加速度。
void EventDispatcherTest::funEventAcceleration()
{ //��佑布��O��
Device::setAccelerometerEnabled(true);
auto listener = EventListenerAcceleration::create(CC_CALLBACK_2(EventDispatcherTest::onAcceleration,this)); this->_eventDispatcher->addEventListenerWithSceneGraphPriority(listener,this);
}void EventDispatcherTest::onAcceleration(Acceleration* acc,Event* event)
{ char str[100]={};
sprintf_s(str,"x:%2d,y:%2d,z:%2d,timestamp:%2d",acc->x,acc->y,acc->z,acc->timestamp);
log(str);
}