|
1 /* |
|
2 * Copyright (c) 1998-2009 Nokia Corporation and/or its subsidiary(-ies). |
|
3 * All rights reserved. |
|
4 * This component and the accompanying materials are made available |
|
5 * under the terms of "Eclipse Public License v1.0" |
|
6 * which accompanies this distribution, and is available |
|
7 * at the URL "http://www.eclipse.org/legal/epl-v10.html". |
|
8 * |
|
9 * Initial Contributors: |
|
10 * Nokia Corporation - initial contribution. |
|
11 * |
|
12 * Contributors: |
|
13 * |
|
14 * Description: |
|
15 * The Open Font rasterizer plug-in Interface Definition class. |
|
16 * |
|
17 */ |
|
18 |
|
19 |
|
20 #ifndef OPENFONTRASTERIZER_H |
|
21 #define OPENFONTRASTERIZER_H |
|
22 |
|
23 class COpenFontFile; |
|
24 |
|
25 /** |
|
26 Supplied to COpenFontRasterizer::ExtendedInterface() to access the extended |
|
27 API interface MOpenFontLinkedTypefaceExtension. |
|
28 |
|
29 @see COpenFontRasterizer::ExtendedInterface() |
|
30 @see MOpenFontLinkedTypefaceExtension |
|
31 @publishedPartner |
|
32 @prototype |
|
33 */ |
|
34 const TUid KUidLinkedTypefaceRasterizerExtension = {0x10285EAA}; |
|
35 |
|
36 /** |
|
37 The Open Font rasterizer plug-in Interface Definition class. |
|
38 |
|
39 This interface allows the implementation of an Open Font rasterizer plug-in, |
|
40 which can then be dynamically loaded at run time by the ECOM plug-in framework. |
|
41 The plug-in implementation is instantiated by calling NewL(), passing the implementation |
|
42 UID so that ECOM can instantiate the correct implementation. |
|
43 |
|
44 The rasterizer interface declares a single pure virtual functions, which the |
|
45 plug-in derived from this interface must implement. The function reads font files, and creates |
|
46 a COpenFontFile object if the font file is of the right type. |
|
47 |
|
48 Writing derived classes: |
|
49 |
|
50 Open font rasterizers should derive from this class and implement the |
|
51 NewFontFileL() function. |
|
52 |
|
53 Derived classes should also define the factory function. It is a static function |
|
54 which takes no arguments. It creates a COpenFontRasterizer derived object on the heap, and returns it |
|
55 to the caller. This factory function, together with the implementation UID will form |
|
56 the TImplementationProxy used by the ECOM framework to instatiate the plug-in. |
|
57 |
|
58 The rasterizer class may also need to store an 'engine context'. This is an |
|
59 object derived from COpenFontRasterizerContext, which provides functions that |
|
60 make it easier to write the glyph bitmap during rasterization. |
|
61 |
|
62 |
|
63 @publishedPartner |
|
64 @released |
|
65 */ |
|
66 class COpenFontRasterizer: public CBase |
|
67 { |
|
68 public: |
|
69 /** Creates a COpenFontFile derived object for loading font files in the |
|
70 new format. |
|
71 |
|
72 This function is called by the framework during font and bitmap server |
|
73 startup. It creates a font file object for font files in the \\resource\\fonts |
|
74 directory on all drives, using the default search path. The first font of |
|
75 a given name overrides subsequent ones. The directory search path is soft |
|
76 to hard: Y:, X:, W:, ..., C:, B:, A:, Z:. Files may also be added |
|
77 dynamically after startup using CWsScreenDevice::AddFile(), which |
|
78 indirectly calls this function. |
|
79 |
|
80 Implementations of this function should examine the file aFileName, and if |
|
81 it is of the correct type attempt to create a COpenFontFile derived object |
|
82 to load it. The caller is responsible for deleting the object. The function |
|
83 must return NULL if it cannot recognise the file, and it may also leave if |
|
84 there is an error. |
|
85 |
|
86 @param aUid An ID to be used for the file. UIDs are required by the font |
|
87 framework, so the font store allocates them for non Symbian OS-native font |
|
88 files. This ID persists until the font is unloaded, e.g. if the device is |
|
89 rebooted. |
|
90 @param aFileName The full path and filename of the file from which the COpenFontFile |
|
91 object is created, if the file is the correct type. |
|
92 @param aFileSession The file session owned by the Font and Bitmap server. This file session |
|
93 should be used for any file access. If COpenFontFile objects need to keep |
|
94 files open, aFileSession should be stored in a place that is accessible to them. |
|
95 @return A pointer to a new COpenFontFile derived object, or NULL if the file type is not recognised. |
|
96 @see CWsScreenDevice::AddFile() */ |
|
97 virtual COpenFontFile* NewFontFileL(TInt aUid,const TDesC& aFileName,RFs& aFileSession) = 0; |
|
98 inline static COpenFontRasterizer* NewL(TUid aInterfaceImplUid); |
|
99 inline virtual ~COpenFontRasterizer(); |
|
100 IMPORT_C virtual void ExtendedInterface(TUid aUid, TAny*& aParam); |
|
101 private: |
|
102 TUid iDtor_ID_Key;//ECOM identifier used during destruction |
|
103 }; |
|
104 |
|
105 /** Uses ECOM plug-in framework to instantiate the Open Font rasterizer interface |
|
106 implementation given its implementation UID. |
|
107 |
|
108 @param aInterfaceImplUid The UID of the interface implementation required |
|
109 |
|
110 @return COpenFontRasterizer* A pointer to a COpenFontRasterizer object. */ |
|
111 inline COpenFontRasterizer* COpenFontRasterizer::NewL(TUid aInterfaceImplUid) |
|
112 { |
|
113 return reinterpret_cast <COpenFontRasterizer*> ( |
|
114 REComSession::CreateImplementationL( |
|
115 aInterfaceImplUid, |
|
116 _FOFF(COpenFontRasterizer, iDtor_ID_Key))); |
|
117 } |
|
118 |
|
119 /** Default destructor */ |
|
120 inline COpenFontRasterizer::~COpenFontRasterizer() |
|
121 { |
|
122 REComSession::DestroyedImplementation(iDtor_ID_Key); |
|
123 } |
|
124 |
|
125 #endif /*OPENFONTRASTERIZER_H*/ |