gifanimationengine.cpp

《基于Symbian OS的手机开发与应用实践》这本书的配套源码。

/*
* ============================================================================
*  Name     : CGifAnimationEngine from GifAnimationEngine.cpp
*  Part of  : GifAnimation
*  Created  : 30.01.2006 by ToBeReplacedByAuthor
*  Implementation notes:
*     
*  Version  :
*  Copyright: ToBeReplacedByCopyright
* ============================================================================
*/

// INCLUDE FILES
#include <coemain.h>

#include "GifAnimationEngine.h"


// ================= MEMBER FUNCTIONS =======================

// Two-phased constructor.
CGifAnimationEngine* CGifAnimationEngine::NewL(MObserver& aObserver)
    {
    CGifAnimationEngine* self = new(ELeave) CGifAnimationEngine(aObserver);
    CleanupStack::PushL( self );
    self->ConstructL();
    CleanupStack::Pop();
    return self; 
    }

// destructor
CGifAnimationEngine::~CGifAnimationEngine()
    {
    DoCancel();
    }

void CGifAnimationEngine::LoadL(const TFileName& aFileName)
    {
    DoCancel();

    iImageDecoder = CImageDecoder::FileNewL(CCoeEnv::Static()->FsSession(), aFileName);
    iArray = new(ELeave) CBitmapPointerArray(5);
    if(iImageDecoder->FrameCount()>0)
        {
        iIndex = 0;
        LoadFrameL(iIndex);
        }
    else
        {
        TRequestStatus* s=&iStatus;
        User::RequestComplete(s, KErrCorrupt);
        SetActive();
        }
    }

void CGifAnimationEngine::RunL()
    {
    // Transfer ownership
    iArray->AppendL(iBitmap);
    iBitmap = NULL;

    iIndex++;
    if(iIndex==iImageDecoder->FrameCount())
        {
        iObserver.OnCompleteL(iArray, iStatus.Int());
        iArray = NULL;
        DoCancel();
        }
    else
        {
        LoadFrameL(iIndex);
        }
    }

void CGifAnimationEngine::DoCancel()
    {
    if(iImageDecoder!=NULL)
        {
        iImageDecoder->Cancel();
        }
    delete iImageDecoder;
    iImageDecoder = NULL;

    if(iArray!=NULL)
        {
        iArray->ResetAndDestroy();
        }
    delete iArray;
    iArray = NULL;

    delete iBitmap;
    iBitmap = NULL;

    iIndex=-1;
    }

// constructor
CGifAnimationEngine::CGifAnimationEngine(MObserver& aObserver ) : 
    CActive(EPriorityStandard), iObserver(aObserver), iIndex(-1)
    {
    }

// EPOC default constructor can leave.
void CGifAnimationEngine::ConstructL()
    {
    CActiveScheduler::Add( this );
    }

void CGifAnimationEngine::LoadFrameL(TInt aIndex)
    {
    TFrameInfo frameInfo = iImageDecoder->FrameInfo(aIndex);
    TRect rect = frameInfo.iFrameCoordsInPixels;

    iBitmap = new(ELeave) CFbsBitmap;
    iBitmap->Create(rect.Size(), frameInfo.iFrameDisplayMode);

    iImageDecoder->Convert(&iStatus, *iBitmap, aIndex);

    SetActive();
    }

// End of File