axmol/cocos/2d/CCEventDispatcher.h

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

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#ifndef __CC_EVENT_DISPATCHER_H__
#define __CC_EVENT_DISPATCHER_H__

#include "CCPlatformMacros.h"
#include "CCEventListener.h"
#include "CCEvent.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 listener type */
    void removeListeners(EventListener::Type eventListenerType);
    
    /** 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);
    
    /** Sets the dirty flag for a node. */
    void setDirtyForNode(Node* node);
    
    /** Notifys event dispatcher that the node has been paused. */
    void pauseTarget(Node* node);
    
    /** Notifys event dispatcher that the node has been resumed. */
    void resumeTarget(Node* node);
    
    /** Notifys event dispatcher that the node has been deleted. */
    void cleanTarget(Node* node);
    
public:
    /** Destructor of EventDispatcher */
    ~EventDispatcher();

private:
    
    /**
     *  The vector to store event listeners with scene graph based priority and fixed priority.
     */
    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 listener type. */
    EventListenerVector* getListeners(EventListener::Type eventListenerType);
    
    /** Update dirty flag */
    void updateDirtyFlagForSceneGraph();
    
    /** Sort event listener */
    void sortEventListeners(EventListener::Type eventListenerType);
    
    /** Sorts the listeners of specified type by scene graph priority */
    void sortEventListenersOfSceneGraphPriority(EventListener::Type eventListenerType);
    
    /** Sorts the listeners of specified type by fixed priority */
    void sortEventListenersOfFixedPriority(EventListener::Type eventListenerType);
    
    /** 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(Event::Type eventType);

    /** 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);
    
    /** Associates node with event listener */
    void associateNodeAndEventListener(Node* node, EventListener* listener);
    
    /** Dissociates node with event listener */
    void dissociateNodeAndEventListener(Node* node, EventListener* listener);
    
    /** Dispatches event to listeners with a specified listener type */
    void dispatchEventToListeners(EventListenerVector* listeners, std::function<bool(EventListener*)> onEvent);
    
    /// Priority dirty flag
    enum class DirtyFlag
    {
        NONE = 0,
        FIXED_PRITORY = 1 << 0,
        SCENE_GRAPH_PRIORITY = 1 << 1,
        ALL = FIXED_PRITORY | SCENE_GRAPH_PRIORITY
    };
    
    /** Sets the dirty flag for a specified listener type */
    void setDirty(EventListener::Type listenerType, DirtyFlag flag);
    
    /** Walks though scene graph to get the draw order for each node, it's called before sorting event listener with scene graph priority */
    void visitTarget(Node* node);
    
private:
    /** Listeners map */
    std::unordered_map<EventListener::Type, EventListenerVector*> _listeners;
    
    /** The map of dirty flag */
    std::unordered_map<EventListener::Type, DirtyFlag> _priorityDirtyFlagMap;
    
    /** The map of node and event listeners */
    std::unordered_map<Node*, std::vector<EventListener*>*> _nodeListenersMap;
    
    /** The map of node and its event priority */
    std::unordered_map<Node*, int> _nodePriorityMap;
    
    /** The listeners to be added after dispatching event */
    std::vector<EventListener*> _toAddedListeners;
    
    /** The nodes were associated with scene graph based priority listeners */
    std::set<Node*> _dirtyNodes;
    
    /** Whether the dispatcher is dispatching event */
    int _inDispatch;
    
    /** Whether to enable dispatching event */
    bool _isEnabled;
};


NS_CC_END


#endif // __CC_EVENT_DISPATCHER_H__