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 font.
49      *
50      *  It is possible that this will return a style set not accessible from
51      *  createStyleSet(int) due to hidden or auto-activated fonts.
52      */
53     SkFontStyleSet* matchFamily(const char familyName[]) const;
54 
55     /**
56      *  Find the closest matching typeface to the specified familyName and style
57      *  and return a ref to it. The caller must call unref() on the returned
58      *  object. Will never return NULL, as it will return the default font if
59      *  no matching font is found.
60      *
61      *  Passing |nullptr| as the parameter for |familyName| will return the
62      *  default system font.
63      *
64      *  It is possible that this will return a style set not accessible from
65      *  createStyleSet(int) or matchFamily(const char[]) due to hidden or
66      *  auto-activated fonts.
67      */
68     SkTypeface* matchFamilyStyle(const char familyName[], const SkFontStyle&) const;
69 
70     /**
71      *  Use the system fallback to find a typeface for the given character.
72      *  Note that bcp47 is a combination of ISO 639, 15924, and 3166-1 codes,
73      *  so it is fine to just pass a ISO 639 here.
74      *
75      *  Will return NULL if no family can be found for the character
76      *  in the system fallback.
77      *
78      *  Passing |nullptr| as the parameter for |familyName| will return the
79      *  default system font.
80      *
81      *  bcp47[0] is the least significant fallback, bcp47[bcp47Count-1] is the
82      *  most significant. If no specified bcp47 codes match, any font with the
83      *  requested character will be matched.
84      */
85     SkTypeface* matchFamilyStyleCharacter(const char familyName[], const SkFontStyle&,
86                                           const char* bcp47[], int bcp47Count,
87                                           SkUnichar character) const;
88 
89     SkTypeface* matchFaceStyle(const SkTypeface*, const SkFontStyle&) const;
90 
91     /**
92      *  Create a typeface for the specified data and TTC index (pass 0 for none)
93      *  or NULL if the data is not recognized. The caller must call unref() on
94      *  the returned object if it is not null.
95      */
96     SkTypeface* createFromData(SkData*, int ttcIndex = 0) const;
97 
98     /**
99      *  Create a typeface for the specified stream and TTC index
100      *  (pass 0 for none) or NULL if the stream is not recognized. The caller
101      *  must call unref() on the returned object if it is not null.
102      */
103     SkTypeface* createFromStream(SkStreamAsset*, int ttcIndex = 0) const;
104 
105     // deprecated, use SkFontArguments instead.
106     using FontParameters = SkFontArguments;
107     /* Experimental, API subject to change. */
108     SkTypeface* createFromStream(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     SkTypeface* createFromFontData(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     SkTypeface* createFromFile(const char path[], int ttcIndex = 0) const;
124 
125     SkTypeface* legacyCreateTypeface(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 SkTypeface* onCreateFromData(SkData*, int ttcIndex) const = 0;
147     virtual SkTypeface* onCreateFromStream(SkStreamAsset*, int ttcIndex) const = 0;
148     // TODO: make pure virtual.
149     virtual SkTypeface* onCreateFromStream(SkStreamAsset*, const SkFontArguments&) const;
150     virtual SkTypeface* onCreateFromFontData(std::unique_ptr<SkFontData>) const;
151     virtual SkTypeface* onCreateFromFile(const char path[], int ttcIndex) const = 0;
152 
153     virtual SkTypeface* onLegacyCreateTypeface(const char familyName[], SkFontStyle) const = 0;
154 
155 private:
156 
157     /** Implemented by porting layer to return the default factory. */
158     static sk_sp<SkFontMgr> Factory();
159 
160     typedef SkRefCnt INHERITED;
161 };
162 
163 #endif
164