1 // Copyright (c) 2005-2009 Nokia Corporation and/or its subsidiary(-ies).
2 // All rights reserved.
3 // This component and the accompanying materials are made available
4 // under the terms of "Eclipse Public License v1.0"
5 // which accompanies this distribution, and is available
6 // at the URL "http://www.eclipse.org/legal/epl-v10.html".
8 // Initial Contributors:
9 // Nokia Corporation - initial contribution.
14 // This is the extension to the plugin API for the Image Display framework
18 #ifndef EXIFIMAGEDISPLAYEXT_H
19 #define EXIFIMAGEDISPLAYEXT_H
22 #include <icl/imagedisplaypluginext.h>
23 #include <icl/exifimagedisplay.hrh>
25 const TUid KExifImageDisplayExtensionUid={KUidExifImageDisplayExtension};
27 class MExifMetadataReader;
30 This class extends the functionality of the Image Display Library client API defined
31 in the class CImageDisplay. This extension is supported only by the EXIF-specific framework
32 plug-ins. In order to invoke the extended functionality, the user needs to call the
33 CImageDisplay::ExtensionInterface( ) with the KExifImageDisplayExtensionUid interface UID
34 and an interface pointer to the object of this class.
39 class MExifImageDisplayExtension :public MImageDisplayPluginExtension
43 Obtains an MExifMetadataReader that can be used to access the EXIF metadata of the image.
44 @param aPtr A reference to a pointer to the MExifMetadataReader that can be used to access the EXIF
45 metadata of the image.
46 @return A system-wide error code.
48 virtual TInt GetExifMetadataReader(MExifMetadataReader*& aPtr)=0;
51 Sets the level of quality for the scaling algorithm.
52 If quality level is not set by calling this function then
53 the fastest/lowest quality algorithm is used.
54 Note: This function must be called before calling CImageDisplay::Play()
56 @param aQualityLevel Quality level value for the scaling algorithm.
57 See CBitmapScaler::TQualityAlgorithm for a set of possible values.
58 @return A system-wide error code.
60 virtual TInt SetScaleQuality(TInt aQualityLevel)=0;
63 Sets the maximum quality reduction factor for image decoding.
64 By default, the plug-in calculates an optimal maximum reduction factor
65 and uses it to produce a series of roughly-decoded images, passing each of
66 them to the observer interface with the CImageDisplayPlugin::EStatusPartialFrame flag set.
67 Note: This function must be called before calling CImageDisplay::Play().
69 @param aMaxReductionFactor
70 The maximum quality reduction factor.
71 Usually the maximum reduction can be specfied in range of 0-3.
72 A value of 0 means no quality reduction is allowed, so a full-quality image will be decoded as the first frame.
73 A value of 1 means (1/2)^1=1/2 of the original image quality.
74 A value of 3 means (1/2)^3=1/8 of the original image quality.
75 If the reduction factor is not set by calling this function then
76 the reduction factor value of 3 is used for jpeg images.
77 @return KErrArgument if the aMaxReductionFactor parameter is not in the supported range, or a system-wide error code.
79 virtual TInt SetMaximumReductionFactor(TInt aMaxReductionFactor)=0;
82 #endif // EXIFIMAGEDISPLAYEXT_H