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IN NO EVENT SHALL THE COPYRIGHT * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. */ #ifndef ComplexTextControllerLinux_h #define ComplexTextControllerLinux_h #include "HarfbuzzSkia.h" #include "SkPoint.h" #include "SkScalar.h" #include "TextRun.h" #include <unicode/uchar.h> #include <wtf/OwnArrayPtr.h> #include <wtf/OwnPtr.h> namespace WebCore { class Font; class FontPlatformData; class SimpleFontData; // ComplexTextController walks a TextRun and presents each script run in sequence. A // TextRun is a sequence of code-points with the same embedding level (i.e. they // are all left-to-right or right-to-left). A script run is a subsequence where // all the characters have the same script (e.g. Arabic, Thai etc). Shaping is // only ever done with script runs since the shapers only know how to deal with // a single script. // // Iteration is always in logical (aka reading) order. For RTL text that means // the rightmost part of the text will be first. // // Once you have setup the object, call |nextScriptRun| to get the first script // run. This will return false when the iteration is complete. At any time you // can call |reset| to start over again. class ComplexTextController { public: ComplexTextController(const TextRun&, unsigned, unsigned, const Font*); ~ComplexTextController(); bool isWordBreak(unsigned); int determineWordBreakSpacing(unsigned); // setPadding sets a number of pixels to be distributed across the TextRun. // WebKit uses this to justify text. void setPadding(int); void reset(unsigned offset); // Advance to the next script run, returning false when the end of the // TextRun has been reached. bool nextScriptRun(); float widthOfFullRun(); // setWordSpacingAdjustment sets a delta (in pixels) which is applied at // each word break in the TextRun. void setWordSpacingAdjustment(int wordSpacingAdjustment) { m_wordSpacingAdjustment = wordSpacingAdjustment; } // setLetterSpacingAdjustment sets an additional number of pixels that is // added to the advance after each output cluster. This matches the behaviour // of WidthIterator::advance. void setLetterSpacingAdjustment(int letterSpacingAdjustment) { m_letterSpacing = letterSpacingAdjustment; } int letterSpacing() const { return m_letterSpacing; } // Set the x offset for the next script run. This affects the values in // |xPositions| bool rtl() const { return m_run.rtl(); } const uint16_t* glyphs() const { return m_glyphs16; } // Return the length of the array returned by |glyphs| const unsigned length() const { return m_item.num_glyphs; } // Return the offset for each of the glyphs. Note that this is translated // by the current x offset and that the x offset is updated for each script // run. const SkPoint* positions() const { return m_positions; } // Get the advances (widths) for each glyph. const HB_Fixed* advances() const { return m_item.advances; } // Return the width (in px) of the current script run. const unsigned width() const { return m_pixelWidth; } // Return the cluster log for the current script run. For example: // script run: f i a n c é (fi gets ligatured) // log clutrs: 0 0 1 2 3 4 // So, for each input code point, the log tells you which output glyph was // generated for it. const unsigned short* logClusters() const { return m_item.log_clusters; } // return the number of code points in the current script run const unsigned numCodePoints() const { return m_item.item.length; } // Return the current pixel position of the controller. const unsigned offsetX() const { return m_offsetX; } const FontPlatformData* fontPlatformDataForScriptRun() { return reinterpret_cast<FontPlatformData*>(m_item.font->userData); } private: void setupFontForScriptRun(); HB_FontRec* allocHarfbuzzFont(); void deleteGlyphArrays(); void createGlyphArrays(int); void resetGlyphArrays(); void shapeGlyphs(); void setGlyphPositions(bool); static void normalizeSpacesAndMirrorChars(const UChar* source, bool rtl, UChar* destination, int length); static const TextRun& getNormalizedTextRun(const TextRun& originalRun, OwnPtr<TextRun>& normalizedRun, OwnArrayPtr<UChar>& normalizedBuffer); // This matches the logic in RenderBlock::findNextLineBreak static bool isCodepointSpace(HB_UChar16 c) { return c == ' ' || c == '\t'; } const Font* const m_font; const SimpleFontData* m_currentFontData; HB_ShaperItem m_item; uint16_t* m_glyphs16; // A vector of 16-bit glyph ids. SkPoint* m_positions; // A vector of positions for each glyph. ssize_t m_indexOfNextScriptRun; // Indexes the script run in |m_run|. unsigned m_offsetX; // Offset in pixels to the start of the next script run. unsigned m_startingY; // The Y starting point of the script run. unsigned m_pixelWidth; // Width (in px) of the current script run. unsigned m_glyphsArrayCapacity; // Current size of all the Harfbuzz arrays. OwnPtr<TextRun> m_normalizedRun; OwnArrayPtr<UChar> m_normalizedBuffer; // A buffer for normalized run. const TextRun& m_run; int m_wordSpacingAdjustment; // delta adjustment (pixels) for each word break. float m_padding; // pixels to be distributed over the line at word breaks. float m_padPerWordBreak; // pixels to be added to each word break. float m_padError; // |m_padPerWordBreak| might have a fractional component. // Since we only add a whole number of padding pixels at // each word break we accumulate error. This is the // number of pixels that we are behind so far. int m_letterSpacing; // pixels to be added after each glyph. String m_smallCapsString; // substring of m_run converted to small caps. }; } // namespace WebCore #endif // ComplexTextControllerLinux_h