1/*
2 * Copyright 2017 Google Inc.
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17#ifndef LIB_TXT_SRC_FONT_COLLECTION_H_
18#define LIB_TXT_SRC_FONT_COLLECTION_H_
19
20#include <memory>
21#include <set>
22#include <string>
23#include <unordered_map>
24#include "flutter/fml/macros.h"
25#include "minikin/FontCollection.h"
26#include "minikin/FontFamily.h"
27#include "third_party/googletest/googletest/include/gtest/gtest_prod.h" // nogncheck
28#include "third_party/skia/include/core/SkFontMgr.h"
29#include "third_party/skia/include/core/SkRefCnt.h"
30#include "txt/asset_font_manager.h"
31#include "txt/text_style.h"
32
33#if FLUTTER_ENABLE_SKSHAPER
34#include "third_party/skia/modules/skparagraph/include/FontCollection.h" // nogncheck
35#endif
36
37namespace txt {
38
39class FontCollection : public std::enable_shared_from_this<FontCollection> {
40 public:
41 FontCollection();
42
43 ~FontCollection();
44
45 size_t GetFontManagersCount() const;
46
47 void SetupDefaultFontManager();
48 void SetDefaultFontManager(sk_sp<SkFontMgr> font_manager);
49 void SetAssetFontManager(sk_sp<SkFontMgr> font_manager);
50 void SetDynamicFontManager(sk_sp<SkFontMgr> font_manager);
51 void SetTestFontManager(sk_sp<SkFontMgr> font_manager);
52
53 std::shared_ptr<minikin::FontCollection> GetMinikinFontCollectionForFamilies(
54 const std::vector<std::string>& font_families,
55 const std::string& locale);
56
57 // Provides a FontFamily that contains glyphs for ch. This caches previously
58 // matched fonts. Also see FontCollection::DoMatchFallbackFont.
59 const std::shared_ptr<minikin::FontFamily>& MatchFallbackFont(
60 uint32_t ch,
61 std::string locale);
62
63 // Do not provide alternative fonts that can match characters which are
64 // missing from the requested font family.
65 void DisableFontFallback();
66
67 // Remove all entries in the font family cache.
68 void ClearFontFamilyCache();
69
70#if FLUTTER_ENABLE_SKSHAPER
71
72 // Construct a Skia text layout FontCollection based on this collection.
73 sk_sp<skia::textlayout::FontCollection> CreateSktFontCollection();
74
75#endif // FLUTTER_ENABLE_SKSHAPER
76
77 private:
78 struct FamilyKey {
79 FamilyKey(const std::vector<std::string>& families, const std::string& loc);
80
81 // Concatenated string with all font families.
82 std::string font_families;
83 std::string locale;
84
85 bool operator==(const FamilyKey& other) const;
86
87 struct Hasher {
88 size_t operator()(const FamilyKey& key) const;
89 };
90 };
91
92 sk_sp<SkFontMgr> default_font_manager_;
93 sk_sp<SkFontMgr> asset_font_manager_;
94 sk_sp<SkFontMgr> dynamic_font_manager_;
95 sk_sp<SkFontMgr> test_font_manager_;
96 std::unordered_map<FamilyKey,
97 std::shared_ptr<minikin::FontCollection>,
98 FamilyKey::Hasher>
99 font_collections_cache_;
100 // Cache that stores the results of MatchFallbackFont to ensure lag-free emoji
101 // font fallback matching.
102 std::unordered_map<uint32_t, const std::shared_ptr<minikin::FontFamily>*>
103 fallback_match_cache_;
104 std::unordered_map<std::string, std::shared_ptr<minikin::FontFamily>>
105 fallback_fonts_;
106 std::unordered_map<std::string, std::vector<std::string>>
107 fallback_fonts_for_locale_;
108 bool enable_font_fallback_;
109
110#if FLUTTER_ENABLE_SKSHAPER
111 // An equivalent font collection usable by the Skia text shaper library.
112 sk_sp<skia::textlayout::FontCollection> skt_collection_;
113#endif
114
115 // Performs the actual work of MatchFallbackFont. The result is cached in
116 // fallback_match_cache_.
117 const std::shared_ptr<minikin::FontFamily>& DoMatchFallbackFont(
118 uint32_t ch,
119 std::string locale);
120
121 std::vector<sk_sp<SkFontMgr>> GetFontManagerOrder() const;
122
123 std::shared_ptr<minikin::FontFamily> FindFontFamilyInManagers(
124 const std::string& family_name);
125
126 std::shared_ptr<minikin::FontFamily> CreateMinikinFontFamily(
127 const sk_sp<SkFontMgr>& manager,
128 const std::string& family_name);
129
130 const std::shared_ptr<minikin::FontFamily>& GetFallbackFontFamily(
131 const sk_sp<SkFontMgr>& manager,
132 const std::string& family_name);
133
134 FML_DISALLOW_COPY_AND_ASSIGN(FontCollection);
135};
136
137} // namespace txt
138
139#endif // LIB_TXT_SRC_FONT_COLLECTION_H_
140