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1 /*
2  * Copyright 2013 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 SkFontMgr_DEFINED
9 #define SkFontMgr_DEFINED
10 
11 #include "SkFontArguments.h"
12 #include "SkFontStyle.h"
13 #include "SkRefCnt.h"
14 #include "SkTypes.h"
15 
16 class SkData;
17 class SkFontData;
18 class SkStreamAsset;
19 class SkString;
20 class SkTypeface;
21 
22 class SK_API SkFontStyleSet : public SkRefCnt {
23 public:
24     virtual int count() = 0;
25     virtual void getStyle(int index, SkFontStyle*, SkString* style) = 0;
26     virtual SkTypeface* createTypeface(int index) = 0;
27     virtual SkTypeface* matchStyle(const SkFontStyle& pattern) = 0;
28 
29     static SkFontStyleSet* CreateEmpty();
30 
31 protected:
32     SkTypeface* matchStyleCSS3(const SkFontStyle& pattern);
33 
34 private:
35     typedef SkRefCnt INHERITED;
36 };
37 
38 class SK_API SkFontMgr : public SkRefCnt {
39 public:
40     int countFamilies() const;
41     void getFamilyName(int index, SkString* familyName) const;
42     SkFontStyleSet* createStyleSet(int index) const;
43 
44     /**
45      *  The caller must call unref() on the returned object.
46      *  Never returns NULL; will return an empty set if the name is not found.
47      *
48      *  Passing nullptr as the parameter will return the default system family.
49      *  Note that most systems don't have a default system family, so passing nullptr will often
50      *  result in the empty set.
51      *
52      *  It is possible that this will return a style set not accessible from
53      *  createStyleSet(int) due to hidden or auto-activated fonts.
54      */
55     SkFontStyleSet* matchFamily(const char familyName[]) const;
56 
57     /**
58      *  Find the closest matching typeface to the specified familyName and style
59      *  and return a ref to it. The caller must call unref() on the returned
60      *  object. Will never return NULL, as it will return the default font if
61      *  no matching font is found.
62      *
63      *  Passing |nullptr| as the parameter for |familyName| will return the
64      *  default system font.
65      *
66      *  It is possible that this will return a style set not accessible from
67      *  createStyleSet(int) or matchFamily(const char[]) due to hidden or
68      *  auto-activated fonts.
69      */
70     SkTypeface* matchFamilyStyle(const char familyName[], const SkFontStyle&) const;
71 
72     /**
73      *  Use the system fallback to find a typeface for the given character.
74      *  Note that bcp47 is a combination of ISO 639, 15924, and 3166-1 codes,
75      *  so it is fine to just pass a ISO 639 here.
76      *
77      *  Will return NULL if no family can be found for the character
78      *  in the system fallback.
79      *
80      *  Passing |nullptr| as the parameter for |familyName| will return the
81      *  default system font.
82      *
83      *  bcp47[0] is the least significant fallback, bcp47[bcp47Count-1] is the
84      *  most significant. If no specified bcp47 codes match, any font with the
85      *  requested character will be matched.
86      */
87     SkTypeface* matchFamilyStyleCharacter(const char familyName[], const SkFontStyle&,
88                                           const char* bcp47[], int bcp47Count,
89                                           SkUnichar character) const;
90 
91     SkTypeface* matchFaceStyle(const SkTypeface*, const SkFontStyle&) const;
92 
93     /**
94      *  Create a typeface for the specified data and TTC index (pass 0 for none)
95      *  or NULL if the data is not recognized. The caller must call unref() on
96      *  the returned object if it is not null.
97      */
98     sk_sp<SkTypeface> makeFromData(sk_sp<SkData>, int ttcIndex = 0) const;
99 
100     /**
101      *  Create a typeface for the specified stream and TTC index
102      *  (pass 0 for none) or NULL if the stream is not recognized. The caller
103      *  must call unref() on the returned object if it is not null.
104      */
105     sk_sp<SkTypeface> makeFromStream(std::unique_ptr<SkStreamAsset>, int ttcIndex = 0) const;
106 
107     /* Experimental, API subject to change. */
108     sk_sp<SkTypeface> makeFromStream(std::unique_ptr<SkStreamAsset>, const SkFontArguments&) const;
109 
110     /**
111      *  Create a typeface from the specified font data.
112      *  Will return NULL if the typeface could not be created.
113      *  The caller must call unref() on the returned object if it is not null.
114      */
115     sk_sp<SkTypeface> makeFromFontData(std::unique_ptr<SkFontData>) const;
116 
117     /**
118      *  Create a typeface for the specified fileName and TTC index
119      *  (pass 0 for none) or NULL if the file is not found, or its contents are
120      *  not recognized. The caller must call unref() on the returned object
121      *  if it is not null.
122      */
123     sk_sp<SkTypeface> makeFromFile(const char path[], int ttcIndex = 0) const;
124 
125     sk_sp<SkTypeface> legacyMakeTypeface(const char familyName[], SkFontStyle style) const;
126 
127     /** Return the default fontmgr. */
128     static sk_sp<SkFontMgr> RefDefault();
129 
130 protected:
131     virtual int onCountFamilies() const = 0;
132     virtual void onGetFamilyName(int index, SkString* familyName) const = 0;
133     virtual SkFontStyleSet* onCreateStyleSet(int index)const  = 0;
134 
135     /** May return NULL if the name is not found. */
136     virtual SkFontStyleSet* onMatchFamily(const char familyName[]) const = 0;
137 
138     virtual SkTypeface* onMatchFamilyStyle(const char familyName[],
139                                            const SkFontStyle&) const = 0;
140     virtual SkTypeface* onMatchFamilyStyleCharacter(const char familyName[], const SkFontStyle&,
141                                                     const char* bcp47[], int bcp47Count,
142                                                     SkUnichar character) const = 0;
143     virtual SkTypeface* onMatchFaceStyle(const SkTypeface*,
144                                          const SkFontStyle&) const = 0;
145 
146     virtual sk_sp<SkTypeface> onMakeFromData(sk_sp<SkData>, int ttcIndex) const = 0;
147     virtual sk_sp<SkTypeface> onMakeFromStreamIndex(std::unique_ptr<SkStreamAsset>,
148                                                     int ttcIndex) const = 0;
149     virtual sk_sp<SkTypeface> onMakeFromStreamArgs(std::unique_ptr<SkStreamAsset>,
150                                                    const SkFontArguments&) const;
151     virtual sk_sp<SkTypeface> onMakeFromFontData(std::unique_ptr<SkFontData>) const;
152     virtual sk_sp<SkTypeface> onMakeFromFile(const char path[], int ttcIndex) const = 0;
153 
154     virtual sk_sp<SkTypeface> onLegacyMakeTypeface(const char familyName[], SkFontStyle) const = 0;
155 
156 private:
157 
158     /** Implemented by porting layer to return the default factory. */
159     static sk_sp<SkFontMgr> Factory();
160 
161     typedef SkRefCnt INHERITED;
162 };
163 
164 #endif
165