| |
| /* |
| * Copyright 2006 The Android Open Source Project |
| * |
| * Use of this source code is governed by a BSD-style license that can be |
| * found in the LICENSE file. |
| */ |
| |
| |
| #ifndef SkTypeface_DEFINED |
| #define SkTypeface_DEFINED |
| |
| #include "SkAdvancedTypefaceMetrics.h" |
| #include "SkWeakRefCnt.h" |
| |
| class SkDescriptor; |
| class SkFontDescriptor; |
| class SkScalerContext; |
| struct SkScalerContextRec; |
| class SkStream; |
| class SkAdvancedTypefaceMetrics; |
| class SkWStream; |
| |
| typedef uint32_t SkFontID; |
| typedef uint32_t SkFontTableTag; |
| |
| /** \class SkTypeface |
| |
| The SkTypeface class specifies the typeface and intrinsic style of a font. |
| This is used in the paint, along with optionally algorithmic settings like |
| textSize, textSkewX, textScaleX, kFakeBoldText_Mask, to specify |
| how text appears when drawn (and measured). |
| |
| Typeface objects are immutable, and so they can be shared between threads. |
| */ |
| class SK_API SkTypeface : public SkWeakRefCnt { |
| public: |
| SK_DECLARE_INST_COUNT(SkTypeface) |
| |
| /** Style specifies the intrinsic style attributes of a given typeface |
| */ |
| enum Style { |
| kNormal = 0, |
| kBold = 0x01, |
| kItalic = 0x02, |
| |
| // helpers |
| kBoldItalic = 0x03 |
| }; |
| |
| /** Returns the typeface's intrinsic style attributes |
| */ |
| Style style() const { return fStyle; } |
| |
| /** Returns true if getStyle() has the kBold bit set. |
| */ |
| bool isBold() const { return (fStyle & kBold) != 0; } |
| |
| /** Returns true if getStyle() has the kItalic bit set. |
| */ |
| bool isItalic() const { return (fStyle & kItalic) != 0; } |
| |
| /** Returns true if the typeface claims to be fixed-pitch. |
| * This is a style bit, advance widths may vary even if this returns true. |
| */ |
| bool isFixedPitch() const { return fIsFixedPitch; } |
| |
| /** Return a 32bit value for this typeface, unique for the underlying font |
| data. Will never return 0. |
| */ |
| SkFontID uniqueID() const { return fUniqueID; } |
| |
| /** Return the uniqueID for the specified typeface. If the face is null, |
| resolve it to the default font and return its uniqueID. Will never |
| return 0. |
| */ |
| static SkFontID UniqueID(const SkTypeface* face); |
| |
| /** Returns true if the two typefaces reference the same underlying font, |
| handling either being null (treating null as the default font) |
| */ |
| static bool Equal(const SkTypeface* facea, const SkTypeface* faceb); |
| |
| /** |
| * Returns a ref() to the default typeface. The caller must call unref() |
| * when they are done referencing the object. Never returns NULL. |
| */ |
| static SkTypeface* RefDefault(Style style = SkTypeface::kNormal); |
| |
| /** Return a new reference to the typeface that most closely matches the |
| requested familyName and style. Pass null as the familyName to return |
| the default font for the requested style. Will never return null |
| |
| @param familyName May be NULL. The name of the font family. |
| @param style The style (normal, bold, italic) of the typeface. |
| @return reference to the closest-matching typeface. Call must call |
| unref() when they are done. |
| */ |
| static SkTypeface* CreateFromName(const char familyName[], Style style); |
| |
| /** Return a new reference to the typeface that most closely matches the |
| requested typeface and specified Style. Use this call if you want to |
| pick a new style from the same family of the existing typeface. |
| If family is NULL, this selects from the default font's family. |
| |
| @param family May be NULL. The name of the existing type face. |
| @param s The style (normal, bold, italic) of the type face. |
| @return reference to the closest-matching typeface. Call must call |
| unref() when they are done. |
| */ |
| static SkTypeface* CreateFromTypeface(const SkTypeface* family, Style s); |
| |
| /** Return a new typeface given a file. If the file does not exist, or is |
| not a valid font file, returns null. |
| */ |
| static SkTypeface* CreateFromFile(const char path[]); |
| |
| /** Return a new typeface given a stream. If the stream is |
| not a valid font file, returns null. Ownership of the stream is |
| transferred, so the caller must not reference it again. |
| */ |
| static SkTypeface* CreateFromStream(SkStream* stream); |
| |
| /** Write a unique signature to a stream, sufficient to reconstruct a |
| typeface referencing the same font when Deserialize is called. |
| */ |
| void serialize(SkWStream*) const; |
| |
| /** Given the data previously written by serialize(), return a new instance |
| to a typeface referring to the same font. If that font is not available, |
| return null. If an instance is returned, the caller is responsible for |
| calling unref() when they are done with it. |
| */ |
| static SkTypeface* Deserialize(SkStream*); |
| |
| /** Retrieve detailed typeface metrics. Used by the PDF backend. |
| @param perGlyphInfo Indicate what glyph specific information (advances, |
| names, etc.) should be populated. |
| @param glyphIDs For per-glyph info, specify subset of the font by |
| giving glyph ids. Each integer represents a glyph |
| id. Passing NULL means all glyphs in the font. |
| @param glyphIDsCount Number of elements in subsetGlyphIds. Ignored if |
| glyphIDs is NULL. |
| @return The returned object has already been referenced. |
| */ |
| SkAdvancedTypefaceMetrics* getAdvancedTypefaceMetrics( |
| SkAdvancedTypefaceMetrics::PerGlyphInfo perGlyphInfo, |
| const uint32_t* glyphIDs = NULL, |
| uint32_t glyphIDsCount = 0) const; |
| |
| enum Encoding { |
| kUTF8_Encoding, |
| kUTF16_Encoding, |
| kUTF32_Encoding |
| }; |
| |
| /** |
| * Given an array of character codes, of the specified encoding, |
| * optionally return their corresponding glyph IDs (if glyphs is not NULL). |
| * |
| * @param chars pointer to the array of character codes |
| * @param encoding how the characteds are encoded |
| * @param glyphs (optional) returns the corresponding glyph IDs for each |
| * character code, up to glyphCount values. If a character code is |
| * not found in the typeface, the corresponding glyph ID will be 0. |
| * @param glyphCount number of code points in 'chars' to process. If glyphs |
| * is not NULL, then it must point sufficient memory to write |
| * glyphCount values into it. |
| * @return the number of number of continuous non-zero glyph IDs computed |
| * from the beginning of chars. This value is valid, even if the |
| * glyphs parameter is NULL. |
| */ |
| int charsToGlyphs(const void* chars, Encoding encoding, uint16_t glyphs[], |
| int glyphCount) const; |
| |
| /** |
| * Return the number of glyphs in the typeface. |
| */ |
| int countGlyphs() const; |
| |
| // Table getters -- may fail if the underlying font format is not organized |
| // as 4-byte tables. |
| |
| /** Return the number of tables in the font. */ |
| int countTables() const; |
| |
| /** Copy into tags[] (allocated by the caller) the list of table tags in |
| * the font, and return the number. This will be the same as CountTables() |
| * or 0 if an error occured. If tags == NULL, this only returns the count |
| * (the same as calling countTables()). |
| */ |
| int getTableTags(SkFontTableTag tags[]) const; |
| |
| /** Given a table tag, return the size of its contents, or 0 if not present |
| */ |
| size_t getTableSize(SkFontTableTag) const; |
| |
| /** Copy the contents of a table into data (allocated by the caller). Note |
| * that the contents of the table will be in their native endian order |
| * (which for most truetype tables is big endian). If the table tag is |
| * not found, or there is an error copying the data, then 0 is returned. |
| * If this happens, it is possible that some or all of the memory pointed |
| * to by data may have been written to, even though an error has occured. |
| * |
| * @param fontID the font to copy the table from |
| * @param tag The table tag whose contents are to be copied |
| * @param offset The offset in bytes into the table's contents where the |
| * copy should start from. |
| * @param length The number of bytes, starting at offset, of table data |
| * to copy. |
| * @param data storage address where the table contents are copied to |
| * @return the number of bytes actually copied into data. If offset+length |
| * exceeds the table's size, then only the bytes up to the table's |
| * size are actually copied, and this is the value returned. If |
| * offset > the table's size, or tag is not a valid table, |
| * then 0 is returned. |
| */ |
| size_t getTableData(SkFontTableTag tag, size_t offset, size_t length, |
| void* data) const; |
| |
| /** |
| * Return the units-per-em value for this typeface, or zero if there is an |
| * error. |
| */ |
| int getUnitsPerEm() const; |
| |
| /** |
| * Return the family name for this typeface. It will always be returned |
| * encoded as UTF8, but the language of the name is whatever the host |
| * platform chooses. |
| */ |
| void getFamilyName(SkString* name) const; |
| |
| /** |
| * Return a stream for the contents of the font data, or NULL on failure. |
| * If ttcIndex is not null, it is set to the TrueTypeCollection index |
| * of this typeface within the stream, or 0 if the stream is not a |
| * collection. |
| */ |
| SkStream* openStream(int* ttcIndex) const; |
| |
| /** |
| * Search within this typeface's family for a best match to the |
| * specified style, and return a ref to that typeface. Note: the |
| * returned object could be this, if it is the best match, or it |
| * could be a different typeface. Either way, the caller must balance |
| * this call with unref() on the returned object. |
| * |
| * Will never return NULL. |
| */ |
| SkTypeface* refMatchingStyle(Style) const; |
| |
| /** |
| * Return a scalercontext for the given descriptor. If this fails, then |
| * if allowFailure is true, this returns NULL, else it returns a |
| * dummy scalercontext that will not crash, but will draw nothing. |
| */ |
| SkScalerContext* createScalerContext(const SkDescriptor*, |
| bool allowFailure = false) const; |
| |
| // PRIVATE / EXPERIMENTAL -- do not call |
| void filterRec(SkScalerContextRec* rec) const { |
| this->onFilterRec(rec); |
| } |
| // PRIVATE / EXPERIMENTAL -- do not call |
| void getFontDescriptor(SkFontDescriptor* desc, bool* isLocal) const { |
| this->onGetFontDescriptor(desc, isLocal); |
| } |
| |
| protected: |
| /** uniqueID must be unique and non-zero |
| */ |
| SkTypeface(Style style, SkFontID uniqueID, bool isFixedPitch = false); |
| virtual ~SkTypeface(); |
| |
| /** Sets the fixedPitch bit. If used, must be called in the constructor. */ |
| void setIsFixedPitch(bool isFixedPitch) { fIsFixedPitch = isFixedPitch; } |
| |
| friend class SkScalerContext; |
| static SkTypeface* GetDefaultTypeface(Style style = SkTypeface::kNormal); |
| |
| virtual SkScalerContext* onCreateScalerContext(const SkDescriptor*) const = 0; |
| virtual void onFilterRec(SkScalerContextRec*) const = 0; |
| virtual SkAdvancedTypefaceMetrics* onGetAdvancedTypefaceMetrics( |
| SkAdvancedTypefaceMetrics::PerGlyphInfo perGlyphInfo, |
| const uint32_t* glyphIDs, |
| uint32_t glyphIDsCount) const = 0; |
| virtual SkStream* onOpenStream(int* ttcIndex) const = 0; |
| virtual void onGetFontDescriptor(SkFontDescriptor*, bool* isLocal) const = 0; |
| |
| virtual int onCharsToGlyphs(const void* chars, Encoding, uint16_t glyphs[], |
| int glyphCount) const; |
| virtual int onCountGlyphs() const = 0; |
| |
| virtual int onGetUPEM() const = 0; |
| |
| virtual int onGetTableTags(SkFontTableTag tags[]) const; |
| virtual size_t onGetTableData(SkFontTableTag, size_t offset, |
| size_t length, void* data) const; |
| |
| // TODO: make this pure-virtual when all ports have overridden it |
| virtual SkTypeface* onRefMatchingStyle(Style styleBits) const { |
| SkASSERT(!"unimplemented"); |
| this->ref(); |
| return const_cast<SkTypeface*>(this); |
| } |
| |
| private: |
| SkFontID fUniqueID; |
| Style fStyle; |
| bool fIsFixedPitch; |
| |
| friend class SkPaint; |
| friend class SkGlyphCache; // GetDefaultTypeface |
| // just so deprecated fonthost can call protected methods |
| friend class SkFontHost; |
| |
| typedef SkWeakRefCnt INHERITED; |
| }; |
| |
| #endif |