1 2 /* 3 * Copyright 2006 The Android Open Source Project 4 * 5 * Use of this source code is governed by a BSD-style license that can be 6 * found in the LICENSE file. 7 */ 8 9 10 #ifndef SkTypeface_DEFINED 11 #define SkTypeface_DEFINED 12 13 #include "SkAdvancedTypefaceMetrics.h" 14 #include "SkRefCnt.h" 15 16 class SkStream; 17 class SkAdvancedTypefaceMetrics; 18 class SkWStream; 19 20 typedef uint32_t SkFontID; 21 22 /** \class SkTypeface 23 24 The SkTypeface class specifies the typeface and intrinsic style of a font. 25 This is used in the paint, along with optionally algorithmic settings like 26 textSize, textSkewX, textScaleX, kFakeBoldText_Mask, to specify 27 how text appears when drawn (and measured). 28 29 Typeface objects are immutable, and so they can be shared between threads. 30 */ 31 class SK_API SkTypeface : public SkRefCnt { 32 public: 33 /** Style specifies the intrinsic style attributes of a given typeface 34 */ 35 enum Style { 36 kNormal = 0, 37 kBold = 0x01, 38 kItalic = 0x02, 39 40 // helpers 41 kBoldItalic = 0x03 42 }; 43 44 /** Returns the typeface's intrinsic style attributes 45 */ 46 Style style() const { return fStyle; } 47 48 /** Returns true if getStyle() has the kBold bit set. 49 */ 50 bool isBold() const { return (fStyle & kBold) != 0; } 51 52 /** Returns true if getStyle() has the kItalic bit set. 53 */ 54 bool isItalic() const { return (fStyle & kItalic) != 0; } 55 56 /** Returns true if the typeface is fixed-width 57 */ 58 bool isFixedWidth() const { return fIsFixedWidth; } 59 60 /** Return a 32bit value for this typeface, unique for the underlying font 61 data. Will never return 0. 62 */ 63 SkFontID uniqueID() const { return fUniqueID; } 64 65 /** Return the uniqueID for the specified typeface. If the face is null, 66 resolve it to the default font and return its uniqueID. Will never 67 return 0. 68 */ 69 static SkFontID UniqueID(const SkTypeface* face); 70 71 /** Returns true if the two typefaces reference the same underlying font, 72 handling either being null (treating null as the default font) 73 */ 74 static bool Equal(const SkTypeface* facea, const SkTypeface* faceb); 75 76 /** Return a new reference to the typeface that most closely matches the 77 requested familyName and style. Pass null as the familyName to return 78 the default font for the requested style. Will never return null 79 80 @param familyName May be NULL. The name of the font family. 81 @param style The style (normal, bold, italic) of the typeface. 82 @return reference to the closest-matching typeface. Call must call 83 unref() when they are done. 84 */ 85 static SkTypeface* CreateFromName(const char familyName[], Style style); 86 87 /** Return a new reference to the typeface that covers a set of Unicode 88 code points with the specified Style. Use this call if you want to 89 pick any font that covers a given string of text. 90 91 @param data UTF-16 characters 92 @param bytelength length of data, in bytes 93 @return reference to the closest-matching typeface. Call must call 94 unref() when they are done. 95 */ 96 static SkTypeface* CreateForChars(const void* data, size_t bytelength, 97 Style s); 98 99 /** Return a new reference to the typeface that most closely matches the 100 requested typeface and specified Style. Use this call if you want to 101 pick a new style from the same family of the existing typeface. 102 If family is NULL, this selects from the default font's family. 103 104 @param family May be NULL. The name of the existing type face. 105 @param s The style (normal, bold, italic) of the type face. 106 @return reference to the closest-matching typeface. Call must call 107 unref() when they are done. 108 */ 109 static SkTypeface* CreateFromTypeface(const SkTypeface* family, Style s); 110 111 /** Return a new typeface given a file. If the file does not exist, or is 112 not a valid font file, returns null. 113 */ 114 static SkTypeface* CreateFromFile(const char path[]); 115 116 /** Return a new typeface given a stream. If the stream is 117 not a valid font file, returns null. Ownership of the stream is 118 transferred, so the caller must not reference it again. 119 */ 120 static SkTypeface* CreateFromStream(SkStream* stream); 121 122 /** Write a unique signature to a stream, sufficient to reconstruct a 123 typeface referencing the same font when Deserialize is called. 124 */ 125 void serialize(SkWStream*) const; 126 127 /** Given the data previously written by serialize(), return a new instance 128 to a typeface referring to the same font. If that font is not available, 129 return null. If an instance is returned, the caller is responsible for 130 calling unref() when they are done with it. 131 */ 132 static SkTypeface* Deserialize(SkStream*); 133 134 /** Retrieve detailed typeface metrics. Used by the PDF backend. 135 @param perGlyphInfo Indicate what glyph specific information (advances, 136 names, etc.) should be populated. 137 @param glyphIDs For per-glyph info, specify subset of the font by 138 giving glyph ids. Each integer represents a glyph 139 id. Passing NULL means all glyphs in the font. 140 @param glyphIDsCount Number of elements in subsetGlyphIds. Ignored if 141 glyphIDs is NULL. 142 @return The returned object has already been referenced. 143 */ 144 SkAdvancedTypefaceMetrics* getAdvancedTypefaceMetrics( 145 SkAdvancedTypefaceMetrics::PerGlyphInfo perGlyphInfo, 146 const uint32_t* glyphIDs = NULL, 147 uint32_t glyphIDsCount = 0) const; 148 149 protected: 150 /** uniqueID must be unique (please!) and non-zero 151 */ 152 SkTypeface(Style style, SkFontID uniqueID, bool isFixedWidth = false); 153 virtual ~SkTypeface(); 154 155 private: 156 SkFontID fUniqueID; 157 Style fStyle; 158 bool fIsFixedWidth; 159 160 typedef SkRefCnt INHERITED; 161 }; 162 163 #endif 164
