diff options
Diffstat (limited to 'WebCore/platform/graphics/chromium/UniscribeHelper.h')
| -rw-r--r-- | WebCore/platform/graphics/chromium/UniscribeHelper.h | 414 |
1 files changed, 0 insertions, 414 deletions
diff --git a/WebCore/platform/graphics/chromium/UniscribeHelper.h b/WebCore/platform/graphics/chromium/UniscribeHelper.h deleted file mode 100644 index ffd57db..0000000 --- a/WebCore/platform/graphics/chromium/UniscribeHelper.h +++ /dev/null @@ -1,414 +0,0 @@ -/* - * Copyright (c) 2006, 2007, 2008, 2009, Google Inc. All rights reserved. - * - * Redistribution and use in source and binary forms, with or without - * modification, are permitted provided that the following conditions are - * met: - * - * * Redistributions of source code must retain the above copyright - * notice, this list of conditions and the following disclaimer. - * * Redistributions in binary form must reproduce the above - * copyright notice, this list of conditions and the following disclaimer - * in the documentation and/or other materials provided with the - * distribution. - * * Neither the name of Google Inc. nor the names of its - * contributors may be used to endorse or promote products derived from - * this software without specific prior written permission. - * - * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS - * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT - * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR - * A PARTICULAR PURPOSE ARE DISCLAIMED. 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. - */ - -// A wrapper around Uniscribe that provides a reasonable API. - -#ifndef UniscribeHelper_h -#define UniscribeHelper_h - -#include <windows.h> -#include <usp10.h> -#include <map> - -#include <unicode/uchar.h> -#include <wtf/Vector.h> - -class UniscribeTest_TooBig_Test; // A gunit test for UniscribeHelper. - -namespace WebCore { - -class GraphicsContext; - -#define UNISCRIBE_HELPER_STACK_RUNS 8 -#define UNISCRIBE_HELPER_STACK_CHARS 32 - -// This object should be safe to create & destroy frequently, as long as the -// caller preserves the script_cache when possible (this data may be slow to -// compute). -// -// This object is "kind of large" (~1K) because it reserves a lot of space for -// working with to avoid expensive heap operations. Therefore, not only should -// you not worry about creating and destroying it, you should try to not keep -// them around. -class UniscribeHelper { -public: - // Initializes this Uniscribe run with the text pointed to by |run| with - // |length|. The input is NOT null terminated. - // - // The is_rtl flag should be set if the input script is RTL. It is assumed - // that the caller has already divided up the input text (using ICU, for - // example) into runs of the same direction of script. This avoids - // disagreements between the caller and Uniscribe later (see FillItems). - // - // A script cache should be provided by the caller that is initialized to - // NULL. When the caller is done with the cache (it may be stored between - // runs as long as it is used consistently with the same HFONT), it should - // call ScriptFreeCache(). - UniscribeHelper(const UChar* input, - int inputLength, - bool isRtl, - HFONT, - SCRIPT_CACHE*, - SCRIPT_FONTPROPERTIES*); - - virtual ~UniscribeHelper(); - - // Sets Uniscribe's directional override flag. False by default. - bool directionalOverride() const - { - return m_directionalOverride; - } - void setDirectionalOverride(bool override) - { - m_directionalOverride = override; - } - - // Set's Uniscribe's no-ligate override flag. False by default. - bool inhibitLigate() const - { - return m_inhibitLigate; - } - void setInhibitLigate(bool inhibit) - { - m_inhibitLigate = inhibit; - } - - // Set letter spacing. We will try to insert this much space between - // graphemes (one or more glyphs perceived as a single unit by ordinary - // users of a script). Positive values increase letter spacing, negative - // values decrease it. 0 by default. - int letterSpacing() const - { - return m_letterSpacing; - } - void setLetterSpacing(int letterSpacing) - { - m_letterSpacing = letterSpacing; - } - - // Set the width of a standard space character. We use this to normalize - // space widths. Windows will make spaces after Hindi characters larger than - // other spaces. A space_width of 0 means to use the default space width. - // - // Must be set before Init() is called. - int spaceWidth() const - { - return m_spaceWidth; - } - void setSpaceWidth(int spaceWidth) - { - m_spaceWidth = spaceWidth; - } - - // Set word spacing. We will try to insert this much extra space between - // each word in the input (beyond whatever whitespace character separates - // words). Positive values lead to increased letter spacing, negative values - // decrease it. 0 by default. - // - // Must be set before Init() is called. - int wordSpacing() const - { - return m_wordSpacing; - } - void setWordSpacing(int wordSpacing) - { - m_wordSpacing = wordSpacing; - } - - void setAscent(int ascent) - { - m_ascent = ascent; - } - - // When set to true, this class is used only to look up glyph - // indices for a range of Unicode characters without glyph placement. - // By default, it's false. This should be set to true when this - // class is used for glyph index look-up for non-BMP characters - // in GlyphPageNodeChromiumWin.cpp. - void setDisableFontFallback(bool disableFontFallback) - { - m_disableFontFallback = true; - } - - // You must call this after setting any options but before doing any - // other calls like asking for widths or drawing. - void init() - { - initWithOptionalLengthProtection(true); - } - - // Returns the total width in pixels of the text run. - int width() const; - - // Call to justify the text, with the amount of space that should be ADDED - // to get the desired width that the column should be justified to. - // Normally, spaces are inserted, but for Arabic there will be kashidas - // (extra strokes) inserted instead. - // - // This function MUST be called AFTER Init(). - void justify(int additionalSpace); - - // Computes the given character offset into a pixel offset of the beginning - // of that character. - int characterToX(int offset) const; - - // Converts the given pixel X position into a logical character offset into - // the run. For positions appearing before the first character, this will - // return -1. - int xToCharacter(int x) const; - - // Draws the given characters to (x, y) in the given DC. The font will be - // handled by this function, but the font color and other attributes should - // be pre-set. - // - // The y position is the upper left corner, NOT the baseline. - void draw(GraphicsContext* graphicsContext, HDC dc, int x, int y, int from, - int to); - - // Returns the first glyph assigned to the character at the given offset. - // This function is used to retrieve glyph information when Uniscribe is - // being used to generate glyphs for non-complex, non-BMP (above U+FFFF) - // characters. These characters are not otherwise special and have no - // complex shaping rules, so we don't otherwise need Uniscribe, except - // Uniscribe is the only way to get glyphs for non-BMP characters. - // - // Returns 0 if there is no glyph for the given character. - WORD firstGlyphForCharacter(int charOffset) const; - -protected: - // Backend for init. The flag allows the unit test to specify whether we - // should fail early for very long strings like normal, or try to pass the - // long string to Uniscribe. The latter provides a way to force failure of - // shaping. - void initWithOptionalLengthProtection(bool lengthProtection); - - // Tries to preload the font when the it is not accessible. - // This is the default implementation and it does not do anything. - virtual void tryToPreloadFont(HFONT) {} - -private: - friend class UniscribeTest_TooBig_Test; - - // An array corresponding to each item in runs_ containing information - // on each of the glyphs that were generated. Like runs_, this is in - // reading order. However, for rtl text, the characters within each - // item will be reversed. - struct Shaping { - Shaping() - : m_prePadding(0) - , m_hfont(NULL) - , m_scriptCache(NULL) - , m_ascentOffset(0) { - m_abc.abcA = 0; - m_abc.abcB = 0; - m_abc.abcC = 0; - } - - // Returns the number of glyphs (which will be drawn to the screen) - // in this run. - int glyphLength() const - { - return static_cast<int>(m_glyphs.size()); - } - - // Returns the number of characters (that we started with) in this run. - int charLength() const - { - return static_cast<int>(m_logs.size()); - } - - // Returns the advance array that should be used when measuring glyphs. - // The returned pointer will indicate an array with glyph_length() - // elements and the advance that should be used for each one. This is - // either the real advance, or the justified advances if there is one, - // and is the array we want to use for measurement. - const int* effectiveAdvances() const - { - if (m_advance.size() == 0) - return 0; - if (m_justify.size() == 0) - return &m_advance[0]; - return &m_justify[0]; - } - - // This is the advance amount of space that we have added to the - // beginning of the run. It is like the ABC's |A| advance but one that - // we create and must handle internally whenever computing with pixel - // offsets. - int m_prePadding; - - // Glyph indices in the font used to display this item. These indices - // are in screen order. - Vector<WORD, UNISCRIBE_HELPER_STACK_CHARS> m_glyphs; - - // For each input character, this tells us the first glyph index it - // generated. This is the only array with size of the input chars. - // - // All offsets are from the beginning of this run. Multiple characters - // can generate one glyph, in which case there will be adjacent - // duplicates in this list. One character can also generate multiple - // glyphs, in which case there will be skipped indices in this list. - Vector<WORD, UNISCRIBE_HELPER_STACK_CHARS> m_logs; - - // Flags and such for each glyph. - Vector<SCRIPT_VISATTR, UNISCRIBE_HELPER_STACK_CHARS> m_visualAttributes; - - // Horizontal advances for each glyph listed above, this is basically - // how wide each glyph is. - Vector<int, UNISCRIBE_HELPER_STACK_CHARS> m_advance; - - // This contains glyph offsets, from the nominal position of a glyph. - // It is used to adjust the positions of multiple combining characters - // around/above/below base characters in a context-sensitive manner so - // that they don't bump against each other and the base character. - Vector<GOFFSET, UNISCRIBE_HELPER_STACK_CHARS> m_offsets; - - // Filled by a call to Justify, this is empty for nonjustified text. - // If nonempty, this contains the array of justify characters for each - // character as returned by ScriptJustify. - // - // This is the same as the advance array, but with extra space added - // for some characters. The difference between a glyph's |justify| - // width and it's |advance| width is the extra space added. - Vector<int, UNISCRIBE_HELPER_STACK_CHARS> m_justify; - - // Sizing information for this run. This treats the entire run as a - // character with a preceeding advance, width, and ending advance. The - // B width is the sum of the |advance| array, and the A and C widths - // are any extra spacing applied to each end. - // - // It is unclear from the documentation what this actually means. From - // experimentation, it seems that the sum of the character advances is - // always the sum of the ABC values, and I'm not sure what you're - // supposed to do with the ABC values. - ABC m_abc; - - // Pointers to windows font data used to render this run. - HFONT m_hfont; - SCRIPT_CACHE* m_scriptCache; - - // Ascent offset between the ascent of the primary font - // and that of the fallback font. The offset needs to be applied, - // when drawing a string, to align multiple runs rendered with - // different fonts. - int m_ascentOffset; - }; - - // Computes the runs_ array from the text run. - void fillRuns(); - - // Computes the shapes_ array given an runs_ array already filled in. - void fillShapes(); - - // Fills in the screen_order_ array (see below). - void fillScreenOrder(); - - // Called to update the glyph positions based on the current spacing - // options that are set. - void applySpacing(); - - // Normalizes all advances for spaces to the same width. This keeps windows - // from making spaces after Hindi characters larger, which is then - // inconsistent with our meaure of the width since WebKit doesn't include - // spaces in text-runs sent to uniscribe unless white-space:pre. - void adjustSpaceAdvances(); - - // Returns the total width of a single item. - int advanceForItem(int) const; - - // Shapes a run (pointed to by |input|) using |hfont| first. - // Tries a series of fonts specified retrieved with NextWinFontData - // and finally a font covering characters in |*input|. A string pointed - // by |input| comes from ScriptItemize and is supposed to contain - // characters belonging to a single script aside from characters common to - // all scripts (e.g. space). - bool shape(const UChar* input, int itemLength, int numGlyphs, SCRIPT_ITEM& run, Shaping&); - - // Gets Windows font data for the next best font to try in the list - // of fonts. When there's no more font available, returns false - // without touching any of out params. Need to call ResetFontIndex - // to start scanning of the font list from the beginning. - virtual bool nextWinFontData(HFONT*, SCRIPT_CACHE**, SCRIPT_FONTPROPERTIES**, int* ascent) - { - return false; - } - - // Resets the font index to the first in the list of fonts to try after the - // primaryFont turns out not to work. With fontIndex reset, - // NextWinFontData scans fallback fonts from the beginning. - virtual void resetFontIndex() {} - - // The input data for this run of Uniscribe. See the constructor. - const UChar* m_input; - const int m_inputLength; - const bool m_isRtl; - - // Windows font data for the primary font. In a sense, m_logfont and m_style - // are redundant because m_hfont contains all the information. However, - // invoking GetObject, everytime we need the height and the style, is rather - // expensive so that we cache them. Would it be better to add getter and - // (virtual) setter for the height and the style of the primary font, - // instead of m_logfont? Then, a derived class ctor can set m_ascent, - // m_height and m_style if they're known. Getters for them would have to - // 'infer' their values from m_hfont ONLY when they're not set. - HFONT m_hfont; - SCRIPT_CACHE* m_scriptCache; - SCRIPT_FONTPROPERTIES* m_fontProperties; - int m_ascent; - LOGFONT m_logfont; - int m_style; - - // Options, see the getters/setters above. - bool m_directionalOverride; - bool m_inhibitLigate; - int m_letterSpacing; - int m_spaceWidth; - int m_wordSpacing; - bool m_disableFontFallback; - - // Uniscribe breaks the text into Runs. These are one length of text that is - // in one script and one direction. This array is in reading order. - Vector<SCRIPT_ITEM, UNISCRIBE_HELPER_STACK_RUNS> m_runs; - - Vector<Shaping, UNISCRIBE_HELPER_STACK_RUNS> m_shapes; - - // This is a mapping between reading order and screen order for the items. - // Uniscribe's items array are in reading order. For right-to-left text, - // or mixed (although WebKit's |TextRun| should really be only one - // direction), this makes it very difficult to compute character offsets - // and positions. This list is in screen order from left to right, and - // gives the index into the |m_runs| and |m_shapes| arrays of each - // subsequent item. - Vector<int, UNISCRIBE_HELPER_STACK_RUNS> m_screenOrder; -}; - -} // namespace WebCore - -#endif // UniscribeHelper_h |