• creating an engine instance using NewL

• setting thumbnail parameters using SetThumbnailSizeL(), SetFlags(), and so on

• creating an object source (CThumbnailObjectSource) and using it to request thumbnails

• handling MThumbnailManagerObserver callbacks when the thumbnail request is complete

  #include <thumbnailmanagerobserver.h>
  #include <thumbnailmanager.h>

  class CMyThumbnailControl: public CCoeControl,
                             public MThumbnailManagerObserver
      {
  public:
      CMyThumbnailControl();
      ~CMyThumbnailControl();
      ...

      // Callbacks from MThumbnailManagerObserver for getting thumbnails
      void ThumbnailPreviewReady(
          MThumbnailData& aThumbnail,
          TThumbnailRequestId aId );
      void ThumbnailReady(
          TInt aError, 
          MThumbnailData& aThumbnail, 
          TThumbnailRequestId aId );

  private:
      void ConstructL();
      CThumbnailManager* iManager;
      CFbsBitmap* iBitmap;
      }

  _LIT( KTestFilePath, "e:\\TestImage.jpg" );
  _LIT( KTestFileType, "image/jpeg" );

  void CMyThumbnailControl::ConstructL()
      {
      // Create Thumbnail Manager instance. This object is the observer.
      iManager = CThumbnailManager::NewL( *this ); 

      // Set flags: If the aspect ratio of the media object does not match
      // 4:3 then we would like it to be cropped. We don t mind getting
      // smaller images than requested.
      iManager->SetFlagsL( CThumbnailManager::ECropToAspectRatio |
                           CThumbnailManager::EAllowAnySize );

      // Preferred size is 160x120 (or less)
      iManager->SetSizeL( TSize( 160, 120 ) );

      // Get a preview thumbnail first, if available.
      // The preview thumbnail is delivered via a ThumbnailPreviewReady()
      // callback.
      iManager->SetQualityPreferenceL(
          CThumbnailManager::EOptimizeForQualityWithPreview );

      // Create an object source representing a path to a file on local
      // file system.
      CThumbnailObjectSource* source = CThumbnailObjectSource::NewLC(
          KTestFilePath,   // File path
          KTestFileType ); // Let Thumbnail Manager know it s a JPEG, so
                           // it doesn t need to recognize the file format

      // Issue the request using default priority
      iManager->GetThumbnailL( *source );

      // If GetThumbnailL() did not leave, the ThumbnailReady() callback is
      // now guaranteed to be called, unless the request is cancelled or
      // CThumbnailManager instance is deleted.

      // The source can be deleted immediately after issuing the request
      CleanupStack::PopAndDestroy( source );
      }

  CMyThumbnailControl::~CMyThumbnailControl()
      {
      // Bitmap should be destroyed before Thumbnail Manager
      delete iBitmap;
      delete iManager;
      }

  void CMyThumbnailControl::ThumbnailReady(
      TInt aError,
      MThumbnailData& aThumbnail,
      TThumbnailRequestId aId )
      {
      // This function must not leave.

      delete iBitmap; iBitmap = NULL;
      if ( !aError )
          {
          // Claim ownership of the bitmap instance for later use
          iBitmap = aThumbnail.DetachBitmap();

          // We can now use iBitmap in our Draw() method
          DrawDeferred();
          }
      else
          {
          // An error occurred while getting the thumbnail.
          // Perhaps we should show a broken image icon to the user.
          }
      }

Since

S60 v5.0