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
//自定義事件 funEventCustom(); //2秒後派發一次自定義事件,測試 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);//添加到事件分發器}void EventDispatcherTest::dispatcherCustomEvents(float at) { //派發事件custom_event_1 事件內容為字符串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() { //啟動硬件設備 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); }