cocos3——11.事件分发
发布时间:2020-12-14 16:21:17 所属栏目:百科 来源:网络整理
导读:【纹理】 TextureCache::addImage texture = new (std::nothrow) Texture2D(); // ref = 1,没有autorelease TextureCache::removeUnusedTextures 把引用计数是1的纹理释放掉 TextureCache::removeAllTextures 释放所有缓存的纹理 【事件】 分发顺序:优先级0
【纹理】
TextureCache::addImage texture = new (std::nothrow) Texture2D(); // ref = 1,没有autorelease TextureCache::removeUnusedTextures 把引用计数是1的纹理释放掉 TextureCache::removeAllTextures 释放所有缓存的纹理 【事件】 分发顺序:优先级<0,场景图顺序(从前往后)(优先级=0),优先级>0 注册订阅者: 用场景图优先级方式添加,要绑定node,默认优先级为0 void addEventListenerWithSceneGraphPriority(EventListener* listener,Node* node); 按固定优先级方式添加,不能设置优先级为0(因为0在上面用,有特殊意义) void addEventListenerWithFixedPriority(EventListener* listener,int fixedPriority); 添加的时候是放到一个map去: std::unordered_map<EventListener::ListenerID,EventListenerVector*> _listenerMap; 而侦听id根据不同的事件类型获取的,每种事件对应一个字符串,而用户自定义事件则是事件的名字: static EventListener::ListenerID __getListenerID(Event* event) { EventListener::ListenerID ret; switch (event->getType()) { case Event::Type::ACCELERATION: ret = EventListenerAcceleration::LISTENER_ID; break; case Event::Type::CUSTOM: { auto customEvent = static_cast<EventCustom*>(event); ret = customEvent->getEventName(); } break; case Event::Type::KEYBOARD: ret = EventListenerKeyboard::LISTENER_ID; break; case Event::Type::MOUSE: ret = EventListenerMouse::LISTENER_ID; break; case Event::Type::FOCUS: ret = EventListenerFocus::LISTENER_ID; break; case Event::Type::TOUCH: // Touch listener is very special,it contains two kinds of listeners,EventListenerTouchOneByOne and EventListenerTouchAllAtOnce. // return UNKNOWN instead. CCASSERT(false,"Don't call this method if the event is for touch."); break; #if (CC_TARGET_PLATFORM == CC_PLATFORM_ANDROID || CC_TARGET_PLATFORM == CC_PLATFORM_IOS) case Event::Type::GAME_CONTROLLER: ret = EventListenerController::LISTENER_ID; break; #endif default: CCASSERT(false,"Invalid type!"); break; } return ret; } 暂停、恢复与节点相关的侦听 void resumeEventListenersForTarget(Node* target,bool recursive = false); void pauseEventListenersForTarget(Node* target,bool recursive = false); 开关订阅者 inline void setEnabled(bool enabled) inline bool isEnabled() 设置优先级 void setPriority(EventListener* listener,int fixedPriority); 分发事件: void dispatchEvent(Event* event); void dispatchCustomEvent(const std::string &eventName,void *optionalUserData = nullptr); void EventDispatcher::dispatchEvent(Event* event) { if (!_isEnabled) return; updateDirtyFlagForSceneGraph(); DispatchGuard guard(_inDispatch); if (event->getType() == Event::Type::TOUCH) { dispatchTouchEvent(static_cast<EventTouch*>(event)); return; } auto listenerID = __getListenerID(event); sortEventListeners(listenerID); auto iter = _listenerMap.find(listenerID); if (iter != _listenerMap.end()) { auto listeners = iter->second; auto onEvent = [&event](EventListener* listener) -> bool{ event->setCurrentTarget(listener->getAssociatedNode()); listener->_onEvent(event); return event->isStopped(); }; dispatchEventToListeners(listeners,onEvent); } updateListeners(event); } 分发的过程:先对标记为dirty的侦听者进行排序,然后根据事件的侦听id找到对应的侦听者集合,然后遍历处理。而处理的结果event->isStopped会影响该事件是否继续传递给其他侦听者。 void EventDispatcher::dispatchEventToListeners(EventListenerVector* listeners,const std::function<bool(EventListener*)>& onEvent) { bool shouldStopPropagation = false; auto fixedPriorityListeners = listeners->getFixedPriorityListeners(); auto sceneGraphPriorityListeners = listeners->getSceneGraphPriorityListeners(); ssize_t i = 0; // priority < 0 if (fixedPriorityListeners) { CCASSERT(listeners->getGt0Index() <= static_cast<ssize_t>(fixedPriorityListeners->size()),"Out of range exception!"); if (!fixedPriorityListeners->empty()) { for (; i < listeners->getGt0Index(); ++i) { auto l = fixedPriorityListeners->at(i); if (l->isEnabled() && !l->isPaused() && l->isRegistered() && onEvent(l)) { shouldStopPropagation = true; break; } } } } if (sceneGraphPriorityListeners) { if (!shouldStopPropagation) { // priority == 0,scene graph priority for (auto& l : *sceneGraphPriorityListeners) { if (l->isEnabled() && !l->isPaused() && l->isRegistered() && onEvent(l)) { shouldStopPropagation = true; break; } } } } if (fixedPriorityListeners) { if (!shouldStopPropagation) { // priority > 0 ssize_t size = fixedPriorityListeners->size(); for (; i < size; ++i) { auto l = fixedPriorityListeners->at(i); if (l->isEnabled() && !l->isPaused() && l->isRegistered() && onEvent(l)) { shouldStopPropagation = true; break; } } } } } (编辑:李大同) 【声明】本站内容均来自网络,其相关言论仅代表作者个人观点,不代表本站立场。若无意侵犯到您的权利,请及时与联系站长删除相关内容! |