dnsresolverengine.h

基于Symbian OS的手机开发与应用实践第16章的源代码。清华大学出版社。

/*
* ============================================================================
*  Name     : CDnsResolverEngine from DnsResolverEngine.h
*  Part of  : UdpSocket
*  Created  : 31.01.2006 by ToBeReplacedByAuthor
*  Description:
*     Declares engine for application.
*  Version  :
*  Copyright: ToBeReplacedByCopyright
* ============================================================================
*/

#ifndef DNSRESOLVERENGINE_H
#define DNSRESOLVERENGINE_H

// INCLUDES
#include <e32base.h>
#include <es_sock.h>
#include <in_sock.h>

#include "DnsResolverTimer.h"

// CONSTANTS

// CLASS DECLARATION

/**
*  CDnsResolverEngine application class.
*/
class CDnsResolverEngine : CActive, CDnsResolverTimer::MObserver
    {
    public: // Observer interface
        class MObserver
            {
            public:
                virtual void OnResolvedL(const TDesC& aResult, TInt aError) = 0;
            };

    public: // Constructors and destructor
        /**
        * Two-phased constructor.
        */
        static CDnsResolverEngine* NewL(MObserver& aObserver);

        /**
        * Destructor.
        */
        virtual ~CDnsResolverEngine();

    public: // New functions
        void GetByName(const THostName& aHostName);
        void GetByAddressL(const TDesC& aAddr);
        void GetHostName();

    public: // Functions from CDnsResolverTimer::MObserver
        void OnTimerL(TInt aError);

    protected: // Functions from CActive
        void DoCancel();
        void RunL();

    private:
        /**
        * EPOC default constructor.
        */
        CDnsResolverEngine(MObserver& aObserver);
        void ConstructL();

    private: // member variables
        MObserver& iObserver;
        RSocketServ iSocketServ;
        RHostResolver iHostResolver;
        TInetAddr iInetAddr;
        TNameEntry iNameEntry;
        THostName iHostName;
        enum TState
            {
            EStateIdle,
            EStateGettingHostName,
            EStateGettingByName,
            EStateGettingByAddress
            } iState;

        CDnsResolverTimer* iTimer; // The timeout timer
    };

#endif

// End of File