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
16class SkData;
17class SkFontData;
18class SkStreamAsset;
19class SkString;
20class SkTypeface;
21
22class SK_API SkFontStyleSet : public SkRefCnt {
23public:
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
31protected:
32    SkTypeface* matchStyleCSS3(const SkFontStyle& pattern);
33
34private:
35    typedef SkRefCnt INHERITED;
36};
37
38class SK_API SkFontMgr : public SkRefCnt {
39public:
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
130protected:
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
156private:
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