CUKeyboardPoller.h

//
//  CUKeyboardPoller.h
//  Cornell Extensions to Cocos2D
//
//  This module provides a polling interface for the Keyboard.  Cocos2d decided to
//  make all of its input event-driven. This is a major problem, because it is hard
//  to associate the events with the current animation frame, potentially causing
//  lag.  A poller is an alternative input interface that allows us to query the
//  current state of the keyboard when we need it.
//
//  Author: Walker White
//  Version: 12/5/15
//
#ifndef __CU_KEYBOARD_POLLER_H__
#define __CU_KEYBOARD_POLLER_H__

#include <vector>
#include <unordered_set>
#include <unordered_map>
#include <cocos2d.h>

NS_CC_BEGIN

struct KeyCodeHasher{
    std::size_t operator()(const EventKeyboard::KeyCode& k) const {
        return (std::hash<int>()(static_cast<int>(k)));
    }
};


#pragma mark -
#pragma mark Keyboard Poller

class CC_DLL KeyboardPoller {
private:
    CC_DISALLOW_COPY_AND_ASSIGN(KeyboardPoller);

protected:
    static KeyboardPoller* _gKeyboard;
    EventListenerKeyboard* _keybdListener;
    bool _active;

    std::unordered_set<EventKeyboard::KeyCode,KeyCodeHasher> _previous;
    std::unordered_set<EventKeyboard::KeyCode,KeyCodeHasher> _current;
    std::unordered_map<EventKeyboard::KeyCode,bool,KeyCodeHasher> _changed;

    
public:
#pragma mark Static Methods

    static void start(int priority);

    static void start(Node* node);

    static void stop();

    static KeyboardPoller* getInstance();

    
#pragma mark Keyboard State

    bool isActive() const { return _active; }
    
    void update();

    bool keyDown(EventKeyboard::KeyCode code) const {
        return _current.find(code) != _current.end();
    }

    bool keyPressed(EventKeyboard::KeyCode code) const {
        return _current.find(code) != _current.end() && _previous.find(code) == _previous.end();
    }

    bool keyReleased(EventKeyboard::KeyCode code) {
        return _current.find(code) == _current.end() && _previous.find(code) != _previous.end();
    }
    
    int keyCount() const { return (int)_current.size(); }
    
    const std::vector<EventKeyboard::KeyCode> keySet() const;
    
    
#pragma mark Initializers
CC_CONSTRUCTOR_ACCESS:
    KeyboardPoller();
    
    ~KeyboardPoller();
    
    void init(int priority);
    
    void init(Node* node);
    
    void dispose();

};

NS_CC_END
#endif /* defined(__CU_KEYBOARD_POLLER_H__) */