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1 // Copyright (c) 2005-2009 Nokia Corporation and/or its subsidiary(-ies). |
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2 // All rights reserved. |
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3 // This component and the accompanying materials are made available |
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4 // under the terms of the License "Symbian Foundation License v1.0" to Symbian Foundation members and "Symbian Foundation End User License Agreement v1.0" to non-members |
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5 // which accompanies this distribution, and is available |
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6 // at the URL "http://www.symbianfoundation.org/legal/licencesv10.html". |
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7 // |
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8 // Initial Contributors: |
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9 // Nokia Corporation - initial contribution. |
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10 // |
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11 // Contributors: |
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12 // |
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13 // Description: |
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14 // This is the extension to the plugin API for the Image Display framework |
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15 // |
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16 // |
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17 |
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18 #ifndef EXIFIMAGEDISPLAYEXT_H |
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19 #define EXIFIMAGEDISPLAYEXT_H |
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20 |
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21 #include <e32base.h> |
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22 #include <icl/imagedisplaypluginext.h> |
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23 #include <icl/exifimagedisplay.hrh> |
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24 |
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25 const TUid KExifImageDisplayExtensionUid={KUidExifImageDisplayExtension}; |
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26 |
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27 class MExifMetadataReader; |
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28 |
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29 /** |
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30 This class extends the functionality of the Image Display Library client API defined |
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31 in the class CImageDisplay. This extension is supported only by the EXIF-specific framework |
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32 plug-ins. In order to invoke the extended functionality, the user needs to call the |
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33 CImageDisplay::ExtensionInterface( ) with the KExifImageDisplayExtensionUid interface UID |
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34 and an interface pointer to the object of this class. |
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35 |
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36 @publishedAll |
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37 @released |
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38 */ |
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39 class MExifImageDisplayExtension :public MImageDisplayPluginExtension |
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40 { |
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41 public: |
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42 /** |
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43 Obtains an MExifMetadataReader that can be used to access the EXIF metadata of the image. |
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44 @param aPtr A reference to a pointer to the MExifMetadataReader that can be used to access the EXIF |
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45 metadata of the image. |
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46 @return A system-wide error code. |
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47 */ |
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48 virtual TInt GetExifMetadataReader(MExifMetadataReader*& aPtr)=0; |
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49 |
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50 /** |
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51 Sets the level of quality for the scaling algorithm. |
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52 If quality level is not set by calling this function then |
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53 the fastest/lowest quality algorithm is used. |
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54 Note: This function must be called before calling CImageDisplay::Play() |
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55 |
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56 @param aQualityLevel Quality level value for the scaling algorithm. |
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57 See CBitmapScaler::TQualityAlgorithm for a set of possible values. |
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58 @return A system-wide error code. |
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59 */ |
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60 virtual TInt SetScaleQuality(TInt aQualityLevel)=0; |
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61 |
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62 /** |
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63 Sets the maximum quality reduction factor for image decoding. |
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64 By default, the plug-in calculates an optimal maximum reduction factor |
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65 and uses it to produce a series of roughly-decoded images, passing each of |
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66 them to the observer interface with the CImageDisplayPlugin::EStatusPartialFrame flag set. |
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67 Note: This function must be called before calling CImageDisplay::Play(). |
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68 |
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69 @param aMaxReductionFactor |
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70 The maximum quality reduction factor. |
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71 Usually the maximum reduction can be specfied in range of 0-3. |
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72 A value of 0 means no quality reduction is allowed, so a full-quality image will be decoded as the first frame. |
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73 A value of 1 means (1/2)^1=1/2 of the original image quality. |
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74 A value of 3 means (1/2)^3=1/8 of the original image quality. |
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75 If the reduction factor is not set by calling this function then |
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76 the reduction factor value of 3 is used for jpeg images. |
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77 @return KErrArgument if the aMaxReductionFactor parameter is not in the supported range, or a system-wide error code. |
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78 */ |
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79 virtual TInt SetMaximumReductionFactor(TInt aMaxReductionFactor)=0; |
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80 }; |
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81 |
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82 #endif // EXIFIMAGEDISPLAYEXT_H |