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      1 /*
      2  * Copyright (C) 2013 The Android Open Source Project
      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 MINIKIN_FONT_FAMILY_H
     18 #define MINIKIN_FONT_FAMILY_H
     19 
     20 #include <vector>
     21 #include <string>
     22 
     23 #include <utils/TypeHelpers.h>
     24 
     25 #include <minikin/MinikinRefCounted.h>
     26 #include <minikin/SparseBitSet.h>
     27 
     28 namespace android {
     29 
     30 class MinikinFont;
     31 
     32 // FontLanguage is a compact representation of a bcp-47 language tag. It
     33 // does not capture all possible information, only what directly affects
     34 // font rendering.
     35 class FontLanguage {
     36     friend class FontStyle;
     37 public:
     38     FontLanguage() : mBits(0) { }
     39 
     40     // Parse from string
     41     FontLanguage(const char* buf, size_t size);
     42 
     43     bool operator==(const FontLanguage other) const { return mBits == other.mBits; }
     44     operator bool() const { return mBits != 0; }
     45 
     46     std::string getString() const;
     47 
     48     // 0 = no match, 1 = language matches, 2 = language and script match
     49     int match(const FontLanguage other) const;
     50 
     51 private:
     52     explicit FontLanguage(uint32_t bits) : mBits(bits) { }
     53 
     54     uint32_t bits() const { return mBits; }
     55 
     56     static const uint32_t kBaseLangMask = 0xffff;
     57     static const uint32_t kScriptMask = (1 << 18) - (1 << 16);
     58     static const uint32_t kHansFlag = 1 << 16;
     59     static const uint32_t kHantFlag = 1 << 17;
     60     uint32_t mBits;
     61 };
     62 
     63 // FontStyle represents all style information needed to select an actual font
     64 // from a collection. The implementation is packed into a single 32-bit word
     65 // so it can be efficiently copied, embedded in other objects, etc.
     66 class FontStyle {
     67 public:
     68     FontStyle(int weight = 4, bool italic = false) {
     69         bits = (weight & kWeightMask) | (italic ? kItalicMask : 0);
     70     }
     71     FontStyle(FontLanguage lang, int variant = 0, int weight = 4, bool italic = false) {
     72         bits = (weight & kWeightMask) | (italic ? kItalicMask : 0)
     73                 | (variant << kVariantShift) | (lang.bits() << kLangShift);
     74     }
     75     int getWeight() const { return bits & kWeightMask; }
     76     bool getItalic() const { return (bits & kItalicMask) != 0; }
     77     int getVariant() const { return (bits >> kVariantShift) & kVariantMask; }
     78     FontLanguage getLanguage() const { return FontLanguage(bits >> kLangShift); }
     79 
     80     bool operator==(const FontStyle other) const { return bits == other.bits; }
     81 
     82     hash_t hash() const { return bits; }
     83 private:
     84     static const uint32_t kWeightMask = (1 << 4) - 1;
     85     static const uint32_t kItalicMask = 1 << 4;
     86     static const int kVariantShift = 5;
     87     static const uint32_t kVariantMask = (1 << 2) - 1;
     88     static const int kLangShift = 7;
     89     uint32_t bits;
     90 };
     91 
     92 enum FontVariant {
     93     VARIANT_DEFAULT = 0,
     94     VARIANT_COMPACT = 1,
     95     VARIANT_ELEGANT = 2,
     96 };
     97 
     98 inline hash_t hash_type(const FontStyle &style) {
     99     return style.hash();
    100 }
    101 
    102 // attributes representing transforms (fake bold, fake italic) to match styles
    103 class FontFakery {
    104 public:
    105     FontFakery() : mFakeBold(false), mFakeItalic(false) { }
    106     FontFakery(bool fakeBold, bool fakeItalic) : mFakeBold(fakeBold), mFakeItalic(fakeItalic) { }
    107     // TODO: want to support graded fake bolding
    108     bool isFakeBold() { return mFakeBold; }
    109     bool isFakeItalic() { return mFakeItalic; }
    110 private:
    111     bool mFakeBold;
    112     bool mFakeItalic;
    113 };
    114 
    115 struct FakedFont {
    116     // ownership is the enclosing FontCollection
    117     MinikinFont* font;
    118     FontFakery fakery;
    119 };
    120 
    121 class FontFamily : public MinikinRefCounted {
    122 public:
    123     FontFamily() { }
    124 
    125     FontFamily(FontLanguage lang, int variant) : mLang(lang), mVariant(variant) {
    126     }
    127 
    128     ~FontFamily();
    129 
    130     // Add font to family, extracting style information from the font
    131     bool addFont(MinikinFont* typeface);
    132 
    133     void addFont(MinikinFont* typeface, FontStyle style);
    134     FakedFont getClosestMatch(FontStyle style) const;
    135 
    136     FontLanguage lang() const { return mLang; }
    137     int variant() const { return mVariant; }
    138 
    139     // API's for enumerating the fonts in a family. These don't guarantee any particular order
    140     size_t getNumFonts() const;
    141     MinikinFont* getFont(size_t index) const;
    142     FontStyle getStyle(size_t index) const;
    143 
    144     // Get Unicode coverage. Lifetime of returned bitset is same as receiver.
    145     const SparseBitSet* getCoverage();
    146 private:
    147     void addFontLocked(MinikinFont* typeface, FontStyle style);
    148 
    149     class Font {
    150     public:
    151         Font(MinikinFont* typeface, FontStyle style) :
    152             typeface(typeface), style(style) { }
    153         MinikinFont* typeface;
    154         FontStyle style;
    155     };
    156     FontLanguage mLang;
    157     int mVariant;
    158     std::vector<Font> mFonts;
    159 
    160     SparseBitSet mCoverage;
    161     bool mCoverageValid;
    162 };
    163 
    164 }  // namespace android
    165 
    166 #endif  // MINIKIN_FONT_FAMILY_H
    167