/* -*- Mode: C; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- * * This Source Code Form is subject to the terms of the Mozilla Public * License, v. 2.0. If a copy of the MPL was not distributed with this * file, You can obtain one at http://mozilla.org/MPL/2.0/. */ #ifndef nsBidi_h__ #define nsBidi_h__ #include "nsBidiUtils.h" // Bidi reordering engine from ICU /* * javadoc-style comments are intended to be transformed into HTML * using DOC++ - see * http://www.zib.de/Visual/software/doc++/index.html . * * The HTML documentation is created with * doc++ -H nsBidi.h */ /** * @mainpage BIDI algorithm for Mozilla (from ICU) * *

BIDI algorithm for Mozilla

* * This is an implementation of the Unicode Bidirectional algorithm. * The algorithm is defined in the * Unicode Technical Report 9, * version 5, also described in The Unicode Standard, Version 3.0 .

* *

General remarks about the API:

* * The limit of a sequence of characters is the position just after their * last character, i.e., one more than that position.

* * Some of the API functions provide access to runs. * Such a run is defined as a sequence of characters * that are at the same embedding level * after performing the BIDI algorithm.

* * @author Markus W. Scherer. Ported to Mozilla by Simon Montagu * @version 1.0 */ /** * nsBidiLevel is the type of the level values in this * Bidi implementation. * It holds an embedding level and indicates the visual direction * by its bit 0 (even/odd value).

* * It can also hold non-level values for the * aParaLevel and aEmbeddingLevels * arguments of SetPara; there: *

* * @see nsBidi::SetPara * *

The related constants are not real, valid level values. * NSBIDI_DEFAULT_XXX can be used to specify * a default for the paragraph level for * when the SetPara function * shall determine it but there is no * strongly typed character in the input.

* * Note that the value for NSBIDI_DEFAULT_LTR is even * and the one for NSBIDI_DEFAULT_RTL is odd, * just like with normal LTR and RTL level values - * these special values are designed that way. Also, the implementation * assumes that NSBIDI_MAX_EXPLICIT_LEVEL is odd. * * @see NSBIDI_DEFAULT_LTR * @see NSBIDI_DEFAULT_RTL * @see NSBIDI_LEVEL_OVERRIDE * @see NSBIDI_MAX_EXPLICIT_LEVEL */ typedef uint8_t nsBidiLevel; /** Paragraph level setting. * If there is no strong character, then set the paragraph level to 0 (left-to-right). */ #define NSBIDI_DEFAULT_LTR 0xfe /** Paragraph level setting. * If there is no strong character, then set the paragraph level to 1 (right-to-left). */ #define NSBIDI_DEFAULT_RTL 0xff /** * Maximum explicit embedding level. * (The maximum resolved level can be up to NSBIDI_MAX_EXPLICIT_LEVEL+1). * */ #define NSBIDI_MAX_EXPLICIT_LEVEL 125 /** Bit flag for level input. * Overrides directional properties. */ #define NSBIDI_LEVEL_OVERRIDE 0x80 /** * Special value which can be returned by the mapping functions when a logical * index has no corresponding visual index or vice-versa. * @see GetVisualIndex * @see GetVisualMap * @see GetLogicalIndex * @see GetLogicalMap */ #define NSBIDI_MAP_NOWHERE (-1) /** * nsBidiDirection values indicate the text direction. */ enum nsBidiDirection { /** All left-to-right text This is a 0 value. */ NSBIDI_LTR, /** All right-to-left text This is a 1 value. */ NSBIDI_RTL, /** Mixed-directional text. */ NSBIDI_MIXED }; typedef enum nsBidiDirection nsBidiDirection; /* miscellaneous definitions ------------------------------------------------ */ /** option flags for WriteReverse() */ /** * option bit for WriteReverse(): * keep combining characters after their base characters in RTL runs * * @see WriteReverse */ #define NSBIDI_KEEP_BASE_COMBINING 1 /** * option bit for WriteReverse(): * replace characters with the "mirrored" property in RTL runs * by their mirror-image mappings * * @see WriteReverse */ #define NSBIDI_DO_MIRRORING 2 /** * option bit for WriteReverse(): * remove Bidi control characters * * @see WriteReverse */ #define NSBIDI_REMOVE_BIDI_CONTROLS 8 /* helper macros for each allocated array member */ #define GETDIRPROPSMEMORY(length) \ GetMemory((void **)&mDirPropsMemory, &mDirPropsSize, \ mMayAllocateText, (length)) #define GETLEVELSMEMORY(length) \ GetMemory((void **)&mLevelsMemory, &mLevelsSize, \ mMayAllocateText, (length)) #define GETRUNSMEMORY(length) \ GetMemory((void **)&mRunsMemory, &mRunsSize, \ mMayAllocateRuns, (length)*sizeof(Run)) /* additional macros used by constructor - always allow allocation */ #define GETINITIALDIRPROPSMEMORY(length) \ GetMemory((void **)&mDirPropsMemory, &mDirPropsSize, \ true, (length)) #define GETINITIALLEVELSMEMORY(length) \ GetMemory((void **)&mLevelsMemory, &mLevelsSize, \ true, (length)) #define GETINITIALRUNSMEMORY(length) \ GetMemory((void **)&mRunsMemory, &mRunsSize, \ true, (length)*sizeof(Run)) #define GETINITIALISOLATESMEMORY(length) \ GetMemory((void **)&mIsolatesMemory, &mIsolatesSize, \ true, (length)*sizeof(Isolate)) /* * Sometimes, bit values are more appropriate * to deal with directionality properties. * Abbreviations in these macro names refer to names * used in the Bidi algorithm. */ typedef uint8_t DirProp; #define DIRPROP_FLAG(dir) (1UL<<(dir)) /* special flag for multiple runs from explicit embedding codes */ #define DIRPROP_FLAG_MULTI_RUNS (1UL<<31) /* are there any characters that are LTR or RTL? */ #define MASK_LTR (DIRPROP_FLAG(L)|DIRPROP_FLAG(EN)|DIRPROP_FLAG(AN)|DIRPROP_FLAG(LRE)|DIRPROP_FLAG(LRO)|DIRPROP_FLAG(LRI)) #define MASK_RTL (DIRPROP_FLAG(R)|DIRPROP_FLAG(AL)|DIRPROP_FLAG(RLE)|DIRPROP_FLAG(RLO)|DIRPROP_FLAG(RLI)) #define MASK_R_AL (DIRPROP_FLAG(R)|DIRPROP_FLAG(AL)) /* explicit embedding codes */ #define MASK_EXPLICIT (DIRPROP_FLAG(LRE)|DIRPROP_FLAG(LRO)|DIRPROP_FLAG(RLE)|DIRPROP_FLAG(RLO)|DIRPROP_FLAG(PDF)) /* explicit isolate codes */ #define MASK_ISO (DIRPROP_FLAG(LRI)|DIRPROP_FLAG(RLI)|DIRPROP_FLAG(FSI)|DIRPROP_FLAG(PDI)) #define MASK_BN_EXPLICIT (DIRPROP_FLAG(BN)|MASK_EXPLICIT) /* paragraph and segment separators */ #define MASK_B_S (DIRPROP_FLAG(B)|DIRPROP_FLAG(S)) /* all types that are counted as White Space or Neutral in some steps */ #define MASK_WS (MASK_B_S|DIRPROP_FLAG(WS)|MASK_BN_EXPLICIT|MASK_ISO) /* types that are neutrals or could becomes neutrals in (Wn) */ #define MASK_POSSIBLE_N (DIRPROP_FLAG(O_N)|DIRPROP_FLAG(CS)|DIRPROP_FLAG(ES)|DIRPROP_FLAG(ET)|MASK_WS) /* * These types may be changed to "e", * the embedding type (L or R) of the run, * in the Bidi algorithm (N2) */ #define MASK_EMBEDDING (DIRPROP_FLAG(NSM)|MASK_POSSIBLE_N) /* the dirProp's L and R are defined to 0 and 1 values in nsCharType */ #define GET_LR_FROM_LEVEL(level) ((DirProp)((level)&1)) #define IS_DEFAULT_LEVEL(level) (((level)&0xfe)==0xfe) /* * The following bit is ORed to the property of directional control * characters which are ignored: unmatched PDF or PDI; LRx, RLx or FSI * which would exceed the maximum explicit bidi level. */ #define IGNORE_CC 0x40 #define PURE_DIRPROP(prop) ((prop)&~IGNORE_CC) /* * The following bit is used for the directional isolate status. * Stack entries corresponding to isolate sequences are greater than ISOLATE. */ #define ISOLATE 0x0100 /* number of isolate entries allocated initially without malloc */ #define SIMPLE_ISOLATES_SIZE 5 /* handle surrogate pairs --------------------------------------------------- */ #define IS_FIRST_SURROGATE(uchar) (((uchar)&0xfc00)==0xd800) #define IS_SECOND_SURROGATE(uchar) (((uchar)&0xfc00)==0xdc00) /* get the UTF-32 value directly from the surrogate pseudo-characters */ #define SURROGATE_OFFSET ((0xd800<<10UL)+0xdc00-0x10000) #define GET_UTF_32(first, second) (((first)<<10UL)+(second)-SURROGATE_OFFSET) #define UTF_ERROR_VALUE 0xffff /* definitions with forward iteration --------------------------------------- */ /* * all the macros that go forward assume that * the initial offset is 0<=i>10)+0xd7c0; \ (s)[(i)++]=(char16_t)(c)&0x3ff|0xdc00; \ } \ } /* safe versions with error-checking and optional regularity-checking */ #define UTF16_APPEND_CHAR_SAFE(s, i, length, c) { \ if((PRUInt32)(c)<=0xffff) { \ (s)[(i)++]=(char16_t)(c); \ } else if((PRUInt32)(c)<=0x10ffff) { \ if((i)+1<(length)) { \ (s)[(i)++]=(char16_t)((c)>>10)+0xd7c0; \ (s)[(i)++]=(char16_t)(c)&0x3ff|0xdc00; \ } else /* not enough space */ { \ (s)[(i)++]=UTF_ERROR_VALUE; \ } \ } else /* c>0x10ffff, write error value */ { \ (s)[(i)++]=UTF_ERROR_VALUE; \ } \ } /* definitions with backward iteration -------------------------------------- */ /* * all the macros that go backward assume that * the valid buffer range starts at offset 0 * and that the initial offset is 00) { \ UTF16_BACK_1_UNSAFE(s, i); \ --__N; \ } \ } /* safe versions with error-checking and optional regularity-checking */ #define UTF16_PREV_CHAR_SAFE(s, start, i, c, strict) { \ (c)=(s)[--(i)]; \ if(IS_SECOND_SURROGATE(c)) { \ char16_t __c2; \ if((i)>(start) && IS_FIRST_SURROGATE(__c2=(s)[(i)-1])) { \ --(i); \ (c)=GET_UTF_32(__c2, (c)); \ /* strict: ((c)&0xfffe)==0xfffe is caught by UTF_IS_ERROR() */ \ } else if(strict) {\ /* unmatched second surrogate */ \ (c)=UTF_ERROR_VALUE; \ } \ } else if(strict && IS_FIRST_SURROGATE(c)) { \ /* unmatched first surrogate */ \ (c)=UTF_ERROR_VALUE; \ /* else strict: (c)==0xfffe is caught by UTF_IS_ERROR() */ \ } \ } #define UTF16_BACK_1_SAFE(s, start, i) { \ if(IS_SECOND_SURROGATE((s)[--(i)]) && (i)>(start) && IS_FIRST_SURROGATE((s)[(i)-1])) { \ --(i); \ } \ } #define UTF16_BACK_N_SAFE(s, start, i, n) { \ int32_t __N=(n); \ while(__N>0 && (i)>(start)) { \ UTF16_BACK_1_SAFE(s, start, i); \ --__N; \ } \ } #define UTF_PREV_CHAR_UNSAFE(s, i, c) UTF16_PREV_CHAR_UNSAFE(s, i, c) #define UTF_PREV_CHAR_SAFE(s, start, i, c, strict) UTF16_PREV_CHAR_SAFE(s, start, i, c, strict) #define UTF_BACK_1_UNSAFE(s, i) UTF16_BACK_1_UNSAFE(s, i) #define UTF_BACK_1_SAFE(s, start, i) UTF16_BACK_1_SAFE(s, start, i) #define UTF_BACK_N_UNSAFE(s, i, n) UTF16_BACK_N_UNSAFE(s, i, n) #define UTF_BACK_N_SAFE(s, start, i, n) UTF16_BACK_N_SAFE(s, start, i, n) #define UTF_APPEND_CHAR_UNSAFE(s, i, c) UTF16_APPEND_CHAR_UNSAFE(s, i, c) #define UTF_APPEND_CHAR_SAFE(s, i, length, c) UTF16_APPEND_CHAR_SAFE(s, i, length, c) #define UTF_PREV_CHAR(s, start, i, c) UTF_PREV_CHAR_SAFE(s, start, i, c, false) #define UTF_BACK_1(s, start, i) UTF_BACK_1_SAFE(s, start, i) #define UTF_BACK_N(s, start, i, n) UTF_BACK_N_SAFE(s, start, i, n) #define UTF_APPEND_CHAR(s, i, length, c) UTF_APPEND_CHAR_SAFE(s, i, length, c) struct Isolate { int32_t start1; int16_t stateImp; int16_t state; }; /* Run structure for reordering --------------------------------------------- */ typedef struct Run { int32_t logicalStart; /* first character of the run; b31 indicates even/odd level */ int32_t visualLimit; /* last visual position of the run +1 */ } Run; /* in a Run, logicalStart will get this bit set if the run level is odd */ #define INDEX_ODD_BIT (1UL<<31) #define MAKE_INDEX_ODD_PAIR(index, level) (index|((uint32_t)level<<31)) #define ADD_ODD_BIT_FROM_LEVEL(x, level) ((x)|=((uint32_t)level<<31)) #define REMOVE_ODD_BIT(x) ((x)&=~INDEX_ODD_BIT) #define GET_INDEX(x) ((x)&~INDEX_ODD_BIT) #define GET_ODD_BIT(x) ((uint32_t)(x)>>31) #define IS_ODD_RUN(x) (((x)&INDEX_ODD_BIT)!=0) #define IS_EVEN_RUN(x) (((x)&INDEX_ODD_BIT)==0) typedef uint32_t Flags; enum { DirProp_L=0, DirProp_R=1, DirProp_EN=2, DirProp_AN=3, DirProp_ON=4, DirProp_S=5, DirProp_B=6 }; /* reduced dirProp */ #define IMPTABLEVELS_COLUMNS (DirProp_B + 2) typedef const uint8_t ImpTab[][IMPTABLEVELS_COLUMNS]; typedef const uint8_t (*PImpTab)[IMPTABLEVELS_COLUMNS]; typedef const uint8_t ImpAct[]; typedef const uint8_t *PImpAct; struct LevState { PImpTab pImpTab; /* level table pointer */ PImpAct pImpAct; /* action map array */ int32_t startON; /* start of ON sequence */ int32_t state; /* current state */ int32_t runStart; /* start position of the run */ nsBidiLevel runLevel; /* run level before implicit solving */ }; /** * This class holds information about a paragraph of text * with Bidi-algorithm-related details, or about one line of * such a paragraph.

* Reordering can be done on a line, or on a paragraph which is * then interpreted as one single line.

* * On construction, the class is initially empty. It is assigned * the Bidi properties of a paragraph by SetPara * or the Bidi properties of a line of a paragraph by * SetLine.

* A Bidi class can be reused for as long as it is not deallocated * by calling its destructor.

* SetPara will allocate additional memory for * internal structures as necessary. */ class nsBidi { public: /** @brief Default constructor. * * The nsBidi object is initially empty. It is assigned * the Bidi properties of a paragraph by SetPara() * or the Bidi properties of a line of a paragraph by * GetLine().

* This object can be reused for as long as it is not destroyed.

* SetPara() will allocate additional memory for * internal structures as necessary. * */ nsBidi(); /** @brief Destructor. */ virtual ~nsBidi(); /** * Perform the Unicode Bidi algorithm. It is defined in the * Unicode Technical Report 9, * version 5, * also described in The Unicode Standard, Version 3.0 .

* * This function takes a single plain text paragraph with or without * externally specified embedding levels from styled text * and computes the left-right-directionality of each character.

* * If the entire paragraph consists of text of only one direction, then * the function may not perform all the steps described by the algorithm, * i.e., some levels may not be the same as if all steps were performed. * This is not relevant for unidirectional text.
* For example, in pure LTR text with numbers the numbers would get * a resolved level of 2 higher than the surrounding text according to * the algorithm. This implementation may set all resolved levels to * the same value in such a case.

* * The text must be externally split into separate paragraphs (rule P1). * Paragraph separators (B) should appear at most at the very end. * * @param aText is a pointer to the single-paragraph text that the * Bidi algorithm will be performed on * (step (P1) of the algorithm is performed externally). * The text must be (at least) aLength long. * * @param aLength is the length of the text; if aLength==-1 then * the text must be zero-terminated. * * @param aParaLevel specifies the default level for the paragraph; * it is typically 0 (LTR) or 1 (RTL). * If the function shall determine the paragraph level from the text, * then aParaLevel can be set to * either NSBIDI_DEFAULT_LTR * or NSBIDI_DEFAULT_RTL; * if there is no strongly typed character, then * the desired default is used (0 for LTR or 1 for RTL). * Any other value between 0 and NSBIDI_MAX_EXPLICIT_LEVEL is also valid, * with odd levels indicating RTL. * * @param aEmbeddingLevels (in) may be used to preset the embedding and override levels, * ignoring characters like LRE and PDF in the text. * A level overrides the directional property of its corresponding * (same index) character if the level has the * NSBIDI_LEVEL_OVERRIDE bit set.

* Except for that bit, it must be * aParaLevel<=aEmbeddingLevels[]<=NSBIDI_MAX_EXPLICIT_LEVEL.

* Caution: A copy of this pointer, not of the levels, * will be stored in the nsBidi object; * the aEmbeddingLevels array must not be * deallocated before the nsBidi object is destroyed or reused, * and the aEmbeddingLevels * should not be modified to avoid unexpected results on subsequent Bidi operations. * However, the SetPara and * SetLine functions may modify some or all of the levels.

* After the nsBidi object is reused or destroyed, the caller * must take care of the deallocation of the aEmbeddingLevels array.

* The aEmbeddingLevels array must be * at least aLength long. */ nsresult SetPara(const char16_t *aText, int32_t aLength, nsBidiLevel aParaLevel, nsBidiLevel *aEmbeddingLevels); /** * Get the directionality of the text. * * @param aDirection receives a NSBIDI_XXX value that indicates if the entire text * represented by this object is unidirectional, * and which direction, or if it is mixed-directional. * * @see nsBidiDirection */ nsresult GetDirection(nsBidiDirection* aDirection); /** * Get the paragraph level of the text. * * @param aParaLevel receives a NSBIDI_XXX value indicating the paragraph level * * @see nsBidiLevel */ nsresult GetParaLevel(nsBidiLevel* aParaLevel); #ifdef FULL_BIDI_ENGINE /** * SetLine sets an nsBidi to * contain the reordering information, especially the resolved levels, * for all the characters in a line of text. This line of text is * specified by referring to an nsBidi object representing * this information for a paragraph of text, and by specifying * a range of indexes in this paragraph.

* In the new line object, the indexes will range from 0 to aLimit-aStart.

* * This is used after calling SetPara * for a paragraph, and after line-breaking on that paragraph. * It is not necessary if the paragraph is treated as a single line.

* * After line-breaking, rules (L1) and (L2) for the treatment of * trailing WS and for reordering are performed on * an nsBidi object that represents a line.

* * Important: the line nsBidi object shares data with * aParaBidi. * You must destroy or reuse this object before aParaBidi. * In other words, you must destroy or reuse the nsBidi object for a line * before the object for its parent paragraph. * * @param aParaBidi is the parent paragraph object. * * @param aStart is the line's first index into the paragraph text. * * @param aLimit is just behind the line's last index into the paragraph text * (its last index +1).
* It must be 0<=aStart<=aLimit<=paragraph length. * * @see SetPara */ nsresult SetLine(const nsBidi* aParaBidi, int32_t aStart, int32_t aLimit); /** * Get the length of the text. * * @param aLength receives the length of the text that the nsBidi object was created for. */ nsresult GetLength(int32_t* aLength); /** * Get the level for one character. * * @param aCharIndex the index of a character. * * @param aLevel receives the level for the character at aCharIndex. * * @see nsBidiLevel */ nsresult GetLevelAt(int32_t aCharIndex, nsBidiLevel* aLevel); /** * Get an array of levels for each character.

* * Note that this function may allocate memory under some * circumstances, unlike GetLevelAt. * * @param aLevels receives a pointer to the levels array for the text, * or nullptr if an error occurs. * * @see nsBidiLevel */ nsresult GetLevels(nsBidiLevel** aLevels); #endif // FULL_BIDI_ENGINE /** * Get the bidirectional type for one character. * * @param aCharIndex the index of a character. * * @param aType receives the bidirectional type of the character at aCharIndex. */ nsresult GetCharTypeAt(int32_t aCharIndex, nsCharType* aType); /** * Get a logical run. * This function returns information about a run and is used * to retrieve runs in logical order.

* This is especially useful for line-breaking on a paragraph. * * @param aLogicalStart is the first character of the run. * * @param aLogicalLimit will receive the limit of the run. * The l-value that you point to here may be the * same expression (variable) as the one for * aLogicalStart. * This pointer can be nullptr if this * value is not necessary. * * @param aLevel will receive the level of the run. * This pointer can be nullptr if this * value is not necessary. */ nsresult GetLogicalRun(int32_t aLogicalStart, int32_t* aLogicalLimit, nsBidiLevel* aLevel); /** * Get the number of runs. * This function may invoke the actual reordering on the * nsBidi object, after SetPara * may have resolved only the levels of the text. Therefore, * CountRuns may have to allocate memory, * and may fail doing so. * * @param aRunCount will receive the number of runs. */ nsresult CountRuns(int32_t* aRunCount); /** * Get one run's logical start, length, and directionality, * which can be 0 for LTR or 1 for RTL. * In an RTL run, the character at the logical start is * visually on the right of the displayed run. * The length is the number of characters in the run.

* CountRuns should be called * before the runs are retrieved. * * @param aRunIndex is the number of the run in visual order, in the * range [0..CountRuns-1]. * * @param aLogicalStart is the first logical character index in the text. * The pointer may be nullptr if this index is not needed. * * @param aLength is the number of characters (at least one) in the run. * The pointer may be nullptr if this is not needed. * * @param aDirection will receive the directionality of the run, * NSBIDI_LTR==0 or NSBIDI_RTL==1, * never NSBIDI_MIXED. * * @see CountRuns

* * Example: * @code * int32_t i, count, logicalStart, visualIndex=0, length; * nsBidiDirection dir; * pBidi->CountRuns(&count); * for(i=0; iGetVisualRun(i, &logicalStart, &length, &dir); * if(NSBIDI_LTR==dir) { * do { // LTR * show_char(text[logicalStart++], visualIndex++); * } while(--length>0); * } else { * logicalStart+=length; // logicalLimit * do { // RTL * show_char(text[--logicalStart], visualIndex++); * } while(--length>0); * } * } * @endcode * * Note that in right-to-left runs, code like this places * modifier letters before base characters and second surrogates * before first ones. */ nsresult GetVisualRun(int32_t aRunIndex, int32_t* aLogicalStart, int32_t* aLength, nsBidiDirection* aDirection); #ifdef FULL_BIDI_ENGINE /** * Get the visual position from a logical text position. * If such a mapping is used many times on the same * nsBidi object, then calling * GetLogicalMap is more efficient.

* * Note that in right-to-left runs, this mapping places * modifier letters before base characters and second surrogates * before first ones. * * @param aLogicalIndex is the index of a character in the text. * * @param aVisualIndex will receive the visual position of this character. * * @see GetLogicalMap * @see GetLogicalIndex */ nsresult GetVisualIndex(int32_t aLogicalIndex, int32_t* aVisualIndex); /** * Get the logical text position from a visual position. * If such a mapping is used many times on the same * nsBidi object, then calling * GetVisualMap is more efficient.

* * This is the inverse function to GetVisualIndex. * * @param aVisualIndex is the visual position of a character. * * @param aLogicalIndex will receive the index of this character in the text. * * @see GetVisualMap * @see GetVisualIndex */ nsresult GetLogicalIndex(int32_t aVisualIndex, int32_t* aLogicalIndex); /** * Get a logical-to-visual index map (array) for the characters in the nsBidi * (paragraph or line) object. * * @param aIndexMap is a pointer to an array of GetLength * indexes which will reflect the reordering of the characters. * The array does not need to be initialized.

* The index map will result in aIndexMap[aLogicalIndex]==aVisualIndex.

* * @see GetVisualMap * @see GetVisualIndex */ nsresult GetLogicalMap(int32_t *aIndexMap); /** * Get a visual-to-logical index map (array) for the characters in the nsBidi * (paragraph or line) object. * * @param aIndexMap is a pointer to an array of GetLength * indexes which will reflect the reordering of the characters. * The array does not need to be initialized.

* The index map will result in aIndexMap[aVisualIndex]==aLogicalIndex.

* * @see GetLogicalMap * @see GetLogicalIndex */ nsresult GetVisualMap(int32_t *aIndexMap); /** * This is a convenience function that does not use a nsBidi object. * It is intended to be used for when an application has determined the levels * of objects (character sequences) and just needs to have them reordered (L2). * This is equivalent to using GetLogicalMap on a * nsBidi object. * * @param aLevels is an array with aLength levels that have been determined by * the application. * * @param aLength is the number of levels in the array, or, semantically, * the number of objects to be reordered. * It must be aLength>0. * * @param aIndexMap is a pointer to an array of aLength * indexes which will reflect the reordering of the characters. * The array does not need to be initialized.

* The index map will result in aIndexMap[aLogicalIndex]==aVisualIndex. */ static nsresult ReorderLogical(const nsBidiLevel *aLevels, int32_t aLength, int32_t *aIndexMap); #endif // FULL_BIDI_ENGINE /** * This is a convenience function that does not use a nsBidi object. * It is intended to be used for when an application has determined the levels * of objects (character sequences) and just needs to have them reordered (L2). * This is equivalent to using GetVisualMap on a * nsBidi object. * * @param aLevels is an array with aLength levels that have been determined by * the application. * * @param aLength is the number of levels in the array, or, semantically, * the number of objects to be reordered. * It must be aLength>0. * * @param aIndexMap is a pointer to an array of aLength * indexes which will reflect the reordering of the characters. * The array does not need to be initialized.

* The index map will result in aIndexMap[aVisualIndex]==aLogicalIndex. */ static nsresult ReorderVisual(const nsBidiLevel *aLevels, int32_t aLength, int32_t *aIndexMap); #ifdef FULL_BIDI_ENGINE /** * Invert an index map. * The one-to-one index mapping of the first map is inverted and written to * the second one. * * @param aSrcMap is an array with aLength indexes * which define the original mapping. * * @param aDestMap is an array with aLength indexes * which will be filled with the inverse mapping. * * @param aLength is the length of each array. */ nsresult InvertMap(const int32_t *aSrcMap, int32_t *aDestMap, int32_t aLength); #endif // FULL_BIDI_ENGINE /** * Reverse a Right-To-Left run of Unicode text. * * This function preserves the integrity of characters with multiple * code units and (optionally) modifier letters. * Characters can be replaced by mirror-image characters * in the destination buffer. Note that "real" mirroring has * to be done in a rendering engine by glyph selection * and that for many "mirrored" characters there are no * Unicode characters as mirror-image equivalents. * There are also options to insert or remove Bidi control * characters; see the description of the aDestSize * and aOptions parameters and of the option bit flags. * * Since no Bidi controls are inserted here, this function will never * write more than aSrcLength characters to aDest. * * @param aSrc A pointer to the RTL run text. * * @param aSrcLength The length of the RTL run. * If the NSBIDI_REMOVE_BIDI_CONTROLS option * is set, then the destination length may be less than * aSrcLength. * If this option is not set, then the destination length * will be exactly aSrcLength. * * @param aDest A pointer to where the reordered text is to be copied. * aSrc[aSrcLength] and aDest[aSrcLength] * must not overlap. * * @param aOptions A bit set of options for the reordering that control * how the reordered text is written. * * @param aDestSize will receive the number of characters that were written to aDest. */ nsresult WriteReverse(const char16_t *aSrc, int32_t aSrcLength, char16_t *aDest, uint16_t aOptions, int32_t *aDestSize); protected: friend class nsBidiPresUtils; /** length of the current text */ int32_t mLength; /** memory sizes in bytes */ size_t mDirPropsSize, mLevelsSize, mRunsSize; size_t mIsolatesSize; /** allocated memory */ DirProp* mDirPropsMemory; nsBidiLevel* mLevelsMemory; Run* mRunsMemory; Isolate* mIsolatesMemory; /** indicators for whether memory may be allocated after construction */ bool mMayAllocateText, mMayAllocateRuns; DirProp* mDirProps; nsBidiLevel* mLevels; /** the paragraph level */ nsBidiLevel mParaLevel; /** flags is a bit set for which directional properties are in the text */ Flags mFlags; /** the overall paragraph or line directionality - see nsBidiDirection */ nsBidiDirection mDirection; /** characters after trailingWSStart are WS and are */ /* implicitly at the paraLevel (rule (L1)) - levels may not reflect that */ int32_t mTrailingWSStart; /** fields for line reordering */ int32_t mRunCount; /* ==-1: runs not set up yet */ Run* mRuns; /** for non-mixed text, we only need a tiny array of runs (no malloc()) */ Run mSimpleRuns[1]; /* maxium of current nesting depth of isolate sequences */ /* Within ResolveExplicitLevels() and checkExpicitLevels(), this is the maximal nesting encountered. Within ResolveImplicitLevels(), this is the index of the current isolates stack entry. */ int32_t mIsolateCount; Isolate* mIsolates; /** for simple text, have a small stack (no malloc()) */ Isolate mSimpleIsolates[SIMPLE_ISOLATES_SIZE]; private: void Init(); bool GetMemory(void **aMemory, size_t* aSize, bool aMayAllocate, size_t aSizeNeeded); void Free(); void GetDirProps(const char16_t *aText); void ResolveExplicitLevels(nsBidiDirection *aDirection); nsresult CheckExplicitLevels(nsBidiDirection *aDirection); nsBidiDirection DirectionFromFlags(Flags aFlags); void ProcessPropertySeq(LevState *pLevState, uint8_t _prop, int32_t start, int32_t limit); void ResolveImplicitLevels(int32_t aStart, int32_t aLimit, DirProp aSOR, DirProp aEOR); void AdjustWSLevels(); void SetTrailingWSStart(); bool GetRuns(); void GetSingleRun(nsBidiLevel aLevel); void ReorderLine(nsBidiLevel aMinLevel, nsBidiLevel aMaxLevel); static bool PrepareReorder(const nsBidiLevel *aLevels, int32_t aLength, int32_t *aIndexMap, nsBidiLevel *aMinLevel, nsBidiLevel *aMaxLevel); int32_t doWriteReverse(const char16_t *src, int32_t srcLength, char16_t *dest, uint16_t options); }; #endif // _nsBidi_h_