1 /*
2  * Copyright 2014 Google Inc.
3  *
4  * Use of this source code is governed by a BSD-style license that can be
5  * found in the LICENSE file.
6  */
7 
8 #ifndef SkRemotableFontMgr_DEFINED
9 #define SkRemotableFontMgr_DEFINED
10 
11 #include "SkFontStyle.h"
12 #include "SkRefCnt.h"
13 #include "SkTemplates.h"
14 
15 class SkDataTable;
16 class SkStreamAsset;
17 class SkString;
18 
19 struct SK_API SkFontIdentity {
20     static const uint32_t kInvalidDataId = 0xFFFFFFFF;
21 
22     // Note that fDataId is a data identifier, not a font identifier.
23     // (fDataID, fTtcIndex) can be seen as a font identifier.
24     uint32_t fDataId;
25     uint32_t fTtcIndex;
26 
27     // On Linux/FontConfig there is also the ability to specify preferences for rendering
28     // antialias, embedded bitmaps, autohint, hinting, hintstyle, lcd rendering
29     // may all be set or set to no-preference
30     // (No-preference is resolved against globals set by the platform)
31     // Since they may be selected against, these are really 'extensions' to SkFontStyle.
32     // SkFontStyle should pick these up.
33     SkFontStyle fFontStyle;
34 };
35 
36 class SK_API SkRemotableFontIdentitySet : public SkRefCnt {
37 public:
38     SK_DECLARE_INST_COUNT(SkRemotableFontIdentitySet)
39 
40     SkRemotableFontIdentitySet(int count, SkFontIdentity** data);
41 
count()42     int count() const { return fCount; }
at(int index)43     const SkFontIdentity& at(int index) const { return fData[index]; }
44 
45     static SkRemotableFontIdentitySet* NewEmpty();
46 
47 private:
SkRemotableFontIdentitySet()48     SkRemotableFontIdentitySet() : fCount(0), fData() { }
49 
50     friend SkRemotableFontIdentitySet* sk_remotable_font_identity_set_new();
51 
52     int fCount;
53     SkAutoTMalloc<SkFontIdentity> fData;
54 
55     typedef SkRefCnt INHERITED;
56 };
57 
58 class SK_API SkRemotableFontMgr : public SkRefCnt {
59 public:
60     SK_DECLARE_INST_COUNT(SkRemotableFontMgr)
61 
62     /**
63      *  Returns the names of the known fonts on the system.
64      *  Will not return NULL, will return an empty table if no families exist.
65      *
66      *  The indexes may be used with getIndex(int) and
67      *  matchIndexStyle(int, SkFontStyle).
68      *
69      *  The caller must unref() the returned object.
70      */
71     virtual SkDataTable* getFamilyNames() const = 0;
72 
73     /**
74      *  Returns all of the fonts with the given familyIndex.
75      *  Returns NULL if the index is out of bounds.
76      *  Returns empty if there are no fonts at the given index.
77      *
78      *  The caller must unref() the returned object.
79      */
80     virtual SkRemotableFontIdentitySet* getIndex(int familyIndex) const = 0;
81 
82     /**
83      *  Returns the closest match to the given style in the given index.
84      *  If there are no available fonts at the given index, the return value's
85      *  data id will be kInvalidDataId.
86      */
87     virtual SkFontIdentity matchIndexStyle(int familyIndex, const SkFontStyle&) const = 0;
88 
89     /**
90      *  Returns all the fonts on the system with the given name.
91      *  If the given name is NULL, will return the default font family.
92      *  Never returns NULL; will return an empty set if the name is not found.
93      *
94      *  It is possible that this will return fonts not accessible from
95      *  getIndex(int) or matchIndexStyle(int, SkFontStyle) due to
96      *  hidden or auto-activated fonts.
97      *
98      *  The matching may be done in a system dependent way. The name may be
99      *  matched case-insensitive, there may be system aliases which resolve,
100      *  and names outside the current locale may be considered. However, this
101      *  should only return fonts which are somehow associated with the requested
102      *  name.
103      *
104      *  The caller must unref() the returned object.
105      */
106     virtual SkRemotableFontIdentitySet* matchName(const char familyName[]) const = 0;
107 
108     /**
109      *  Returns the closest matching font to the specified name and style.
110      *  If there are no available fonts which match the name, the return value's
111      *  data id will be kInvalidDataId.
112      *  If the given name is NULL, the match will be against any default fonts.
113      *
114      *  It is possible that this will return a font identity not accessible from
115      *  methods returning sets due to hidden or auto-activated fonts.
116      *
117      *  The matching may be done in a system dependent way. The name may be
118      *  matched case-insensitive, there may be system aliases which resolve,
119      *  and names outside the current locale may be considered. However, this
120      *  should only return a font which is somehow associated with the requested
121      *  name.
122      *
123      *  The caller must unref() the returned object.
124      */
125     virtual SkFontIdentity matchNameStyle(const char familyName[], const SkFontStyle&) const = 0;
126 
127     /**
128      *  Use the system fall-back to find a font for the given character.
129      *  If no font can be found for the character, the return value's data id
130      *  will be kInvalidDataId.
131      *  If the name is NULL, the match will start against any default fonts.
132      *  If the bpc47 is NULL, a default locale will be assumed.
133      *
134      *  Note that bpc47 is a combination of ISO 639, 15924, and 3166-1 codes,
135      *  so it is fine to just pass a ISO 639 here.
136      */
137     virtual SkFontIdentity matchNameStyleCharacter(const char familyName[], const SkFontStyle&,
138                                                    const char* bcp47[], int bcp47Count,
139                                                    SkUnichar character) const=0;
140 
141     /**
142      *  Returns the data for the given data id.
143      *  Will return NULL if the data id is invalid.
144      *  Note that this is a data id, not a font id.
145      *
146      *  The caller must unref() the returned object.
147      */
148     virtual SkStreamAsset* getData(int dataId) const = 0;
149 
150 private:
151     typedef SkRefCnt INHERITED;
152 };
153 
154 #endif
155