axmol/cocos/2d/CCEventDispatcher.h

/****************************************************************************
 Copyright (c) 2013 cocos2d-x.org

 http://www.cocos2d-x.org

 Permission is hereby granted, free of charge, to any person obtaining a copy
 of this software and associated documentation files (the "Software"), to deal
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 all copies or substantial portions of the Software.

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 IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
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 THE SOFTWARE.
 ****************************************************************************/

#ifndef __CC_EVENT_DISPATCHER_H__
#define __CC_EVENT_DISPATCHER_H__

#include "CCPlatformMacros.h"
#include "CCEventListener.h"

#include <functional>
#include <string>
#include <unordered_map>
#include <list>
#include <vector>

NS_CC_BEGIN

class Event;
class EventTouch;
class Node;

/**
This class manages event listener subscriptions
and event dispatching.

The EventListener list is managed in such a way that
event listeners can be added and removed even
from within an EventListener, while events are being
dispatched.
*/
class EventDispatcher
{
public:
    /** Gets the singleton of EventDispatcher */
    static EventDispatcher* getInstance();

    /** Destroys the singleton of EventDispatcher */
    static void destroyInstance();
    
    /** Adds a event listener for a specified event with the priority of scene graph.
     *  @param listener The listener of a specified event.
     *  @param node The priority of the listener is based on the draw order of this node.
     *  @note  The priority of scene graph will be fixed value 0. So the order of listener item
     *          in the vector will be ' <0, scene graph (0 priority), >0'.
     */
    void addEventListenerWithSceneGraphPriority(EventListener* listener, Node* node);

    /** Adds a event listener for a specified event with the fixed priority.
     *  @param listener The listener of a specified event.
     *  @param fixedPriority The fixed priority of the listener.
     *  @note A lower priority will be called before the ones that have a higher value.
     *        0 priority is forbidden for fixed priority since it's used for scene graph based priority.
     */
    void addEventListenerWithFixedPriority(EventListener* listener, int fixedPriority);

    /** Remove a listener 
     *  @param listener The specified event listener which needs to be removed.
     */
    void removeEventListener(EventListener* listener);

    /** Removes all listeners with the same event type */
    void removeListenersForEventType(const std::string& eventType);
    
    /** Removes all listeners */
    void removeAllListeners();

    /** Sets listener's priority with fixed value. */
    void setPriority(EventListener* listener, int fixedPriority);

    /** Whether to enable dispatching events */
    void setEnabled(bool isEnabled);

    /** Checks whether dispatching events is enabled */
    bool isEnabled() const;

    /** Dispatches the event
     *  Also removes all EventListeners marked for deletion from the
     *  event dispatcher list.
     */
    void dispatchEvent(Event* event);
    
    /** Touch event needs to be processed different with other events since it needs support ALL_AT_ONCE and ONE_BY_NONE mode. */
    void dispatchTouchEvent(EventTouch* event);
    
    /// Priority dirty flag
    enum class DirtyFlag
    {
        NONE = 0,
        FIXED_PRITORY = 1 << 0,
        SCENE_GRAPH_PRIORITY = 1 << 1,
        ALL = FIXED_PRITORY | SCENE_GRAPH_PRIORITY
    };
    
    void setDirtyForNode(Node* node);
    
    void pauseTarget(Node* node);
    void resumeTarget(Node* node);
    void cleanTarget(Node* node);
    
public:
    /** Destructor of EventDispatcher */
    ~EventDispatcher();

private:
    
    class EventListenerVector
    {
    public:
        EventListenerVector();
        ~EventListenerVector();
        size_t size() const;
        bool empty() const;
        
        void push_back(EventListener* item);
        void clearSceneGraphListeners();
        void clearFixedListeners();
        void clear();
        
        inline std::vector<EventListener*>* getFixedPriorityListeners() const { return _fixedListeners; };
        inline std::vector<EventListener*>* getSceneGraphPriorityListeners() const { return _sceneGraphListeners; };
        inline int getGt0Index() const { return _gt0Index; };
        inline void setGt0Index(int index) { _gt0Index = index; };
    private:
        std::vector<EventListener*>* _fixedListeners;
        std::vector<EventListener*>* _sceneGraphListeners;
        int _gt0Index;
    };

    /** Constructor of EventDispatcher */
    EventDispatcher();
    
    /** Adds event listener with item */
    void addEventListener(EventListener* listener);
    
    /** Gets event the listener list for the event type. */
    EventListenerVector* getListeners(const std::string& eventType);
    
    void updateDirtyFlagForSceneGraph();
    
    /** Sorts the listeners of specified type by scene graph priority */
    void sortEventListenersOfSceneGraphPriority(const std::string& eventType);
    
    /** Sorts the listeners of specified type by fixed priority */
    void sortEventListenersOfFixedPriority(const std::string& eventType);
    
    /** Updates all listeners
     *  1) Removes all listener items that have been marked as 'removed' when dispatching event.
     *  2) Adds all listener items that have been marked as 'added' when dispatching event.
     */
    void updateListeners();

    void associateNodeAndEventListener(Node* node, EventListener* listener);
    void dissociateNodeAndEventListener(Node* node, EventListener* listener);
    
    void dispatchEventToListeners(EventListenerVector* listeners, std::function<bool(EventListener*)> onEvent);
    
    void setDirtyForEventType(const std::string& eventType, DirtyFlag flag);
    DirtyFlag isDirtyForEventType(const std::string& eventType);
    
    void visitTarget(Node* node);
    
private:
    /**
     * Listeners map.
     */
    std::unordered_map<std::string, EventListenerVector*> _listeners;
    
    std::unordered_map<std::string, DirtyFlag> _priorityDirtyFlagMap;
    
    std::unordered_map<Node*, std::vector<EventListener*>*> _nodeListenersMap;
    std::unordered_map<Node*, int> _nodePriorityMap;
    
    std::vector<EventListener*> _toAddedListeners;
    std::set<Node*> _dirtyNodes;
    
    int   _inDispatch;        ///< Whether it's in dispatching event
    bool  _isEnabled;         ///< Whether to enable dispatching event
};


NS_CC_END


#endif // __CC_EVENT_DISPATCHER_H__