diff options
Diffstat (limited to 'intl/icu/source/common/ubiditransform.cpp')
| -rw-r--r-- | intl/icu/source/common/ubiditransform.cpp | 530 |
1 files changed, 530 insertions, 0 deletions
diff --git a/intl/icu/source/common/ubiditransform.cpp b/intl/icu/source/common/ubiditransform.cpp new file mode 100644 index 0000000000..01f5901a2c --- /dev/null +++ b/intl/icu/source/common/ubiditransform.cpp @@ -0,0 +1,530 @@ +/* +****************************************************************************** +* +* © 2016 and later: Unicode, Inc. and others. +* License & terms of use: http://www.unicode.org/copyright.html +* +****************************************************************************** +* file name: ubiditransform.c +* encoding: UTF-8 +* tab size: 8 (not used) +* indentation:4 +* +* created on: 2016jul24 +* created by: Lina Kemmel +* +*/ + +#include "cmemory.h" +#include "unicode/ubidi.h" +#include "unicode/ustring.h" +#include "unicode/ushape.h" +#include "unicode/utf16.h" +#include "ustr_imp.h" +#include "unicode/ubiditransform.h" + +/* Some convenience defines */ +#define LTR UBIDI_LTR +#define RTL UBIDI_RTL +#define LOGICAL UBIDI_LOGICAL +#define VISUAL UBIDI_VISUAL +#define SHAPE_LOGICAL U_SHAPE_TEXT_DIRECTION_LOGICAL +#define SHAPE_VISUAL U_SHAPE_TEXT_DIRECTION_VISUAL_LTR + +#define CHECK_LEN(STR, LEN, ERROR) UPRV_BLOCK_MACRO_BEGIN { \ + if (LEN == 0) return 0; \ + if (LEN < -1) { *(ERROR) = U_ILLEGAL_ARGUMENT_ERROR; return 0; } \ + if (LEN == -1) LEN = u_strlen(STR); \ +} UPRV_BLOCK_MACRO_END + +#define MAX_ACTIONS 7 + +/** + * Typedef for a pointer to a function, which performs some operation (such as + * reordering, setting "inverse" mode, character mirroring, etc.). Return value + * indicates whether the text was changed in the course of this operation or + * not. + */ +typedef UBool (*UBiDiAction)(UBiDiTransform *, UErrorCode *); + +/** + * Structure that holds a predefined reordering scheme, including the following + * information: + * <ul> + * <li>an input base direction,</li> + * <li>an input order,</li> + * <li>an output base direction,</li> + * <li>an output order,</li> + * <li>a digit shaping direction,</li> + * <li>a letter shaping direction,</li> + * <li>a base direction that should be applied when the reordering engine is + * invoked (which can not always be derived from the caller-defined + * options),</li> + * <li>an array of pointers to functions that accomplish the bidi layout + * transformation.</li> + * </ul> + */ +typedef struct { + UBiDiLevel inLevel; /* input level */ + UBiDiOrder inOrder; /* input order */ + UBiDiLevel outLevel; /* output level */ + UBiDiOrder outOrder; /* output order */ + uint32_t digitsDir; /* digit shaping direction */ + uint32_t lettersDir; /* letter shaping direction */ + UBiDiLevel baseLevel; /* paragraph level to be used with setPara */ + const UBiDiAction actions[MAX_ACTIONS]; /* array of pointers to functions carrying out the transformation */ +} ReorderingScheme; + +struct UBiDiTransform { + UBiDi *pBidi; /* pointer to a UBiDi object */ + const ReorderingScheme *pActiveScheme; /* effective reordering scheme */ + char16_t *src; /* input text */ + char16_t *dest; /* output text */ + uint32_t srcLength; /* input text length - not really needed as we are zero-terminated and can u_strlen */ + uint32_t srcSize; /* input text capacity excluding the trailing zero */ + uint32_t destSize; /* output text capacity */ + uint32_t *pDestLength; /* number of UChars written to dest */ + uint32_t reorderingOptions; /* reordering options - currently only suppot DO_MIRRORING */ + uint32_t digits; /* digit option for ArabicShaping */ + uint32_t letters; /* letter option for ArabicShaping */ +}; + +U_CAPI UBiDiTransform* U_EXPORT2 +ubiditransform_open(UErrorCode *pErrorCode) +{ + UBiDiTransform *pBiDiTransform = nullptr; + if (U_SUCCESS(*pErrorCode)) { + pBiDiTransform = (UBiDiTransform*) uprv_calloc(1, sizeof(UBiDiTransform)); + if (pBiDiTransform == nullptr) { + *pErrorCode = U_MEMORY_ALLOCATION_ERROR; + } + } + return pBiDiTransform; +} + +U_CAPI void U_EXPORT2 +ubiditransform_close(UBiDiTransform *pBiDiTransform) +{ + if (pBiDiTransform != nullptr) { + if (pBiDiTransform->pBidi != nullptr) { + ubidi_close(pBiDiTransform->pBidi); + } + if (pBiDiTransform->src != nullptr) { + uprv_free(pBiDiTransform->src); + } + uprv_free(pBiDiTransform); + } +} + +/** + * Performs Bidi resolution of text. + * + * @param pTransform Pointer to the <code>UBiDiTransform</code> structure. + * @param pErrorCode Pointer to the error code value. + * + * @return Whether or not this function modifies the text. Besides the return + * value, the caller should also check <code>U_SUCCESS(*pErrorCode)</code>. + */ +static UBool +action_resolve(UBiDiTransform *pTransform, UErrorCode *pErrorCode) +{ + ubidi_setPara(pTransform->pBidi, pTransform->src, pTransform->srcLength, + pTransform->pActiveScheme->baseLevel, nullptr, pErrorCode); + return false; +} + +/** + * Performs basic reordering of text (Logical -> Visual LTR). + * + * @param pTransform Pointer to the <code>UBiDiTransform</code> structure. + * @param pErrorCode Pointer to the error code value. + * + * @return Whether or not this function modifies the text. Besides the return + * value, the caller should also check <code>U_SUCCESS(*pErrorCode)</code>. + */ +static UBool +action_reorder(UBiDiTransform *pTransform, UErrorCode *pErrorCode) +{ + ubidi_writeReordered(pTransform->pBidi, pTransform->dest, pTransform->destSize, + static_cast<uint16_t>(pTransform->reorderingOptions), pErrorCode); + + *pTransform->pDestLength = pTransform->srcLength; + pTransform->reorderingOptions = UBIDI_REORDER_DEFAULT; + return true; +} + +/** + * Sets "inverse" mode on the <code>UBiDi</code> object. + * + * @param pTransform Pointer to the <code>UBiDiTransform</code> structure. + * @param pErrorCode Pointer to the error code value. + * + * @return Whether or not this function modifies the text. Besides the return + * value, the caller should also check <code>U_SUCCESS(*pErrorCode)</code>. + */ +static UBool +action_setInverse(UBiDiTransform *pTransform, UErrorCode *pErrorCode) +{ + (void)pErrorCode; + ubidi_setInverse(pTransform->pBidi, true); + ubidi_setReorderingMode(pTransform->pBidi, UBIDI_REORDER_INVERSE_LIKE_DIRECT); + return false; +} + +/** + * Sets "runs only" reordering mode indicating a Logical LTR <-> Logical RTL + * transformation. + * + * @param pTransform Pointer to the <code>UBiDiTransform</code> structure. + * @param pErrorCode Pointer to the error code value. + * + * @return Whether or not this function modifies the text. Besides the return + * value, the caller should also check <code>U_SUCCESS(*pErrorCode)</code>. + */ +static UBool +action_setRunsOnly(UBiDiTransform *pTransform, UErrorCode *pErrorCode) +{ + (void)pErrorCode; + ubidi_setReorderingMode(pTransform->pBidi, UBIDI_REORDER_RUNS_ONLY); + return false; +} + +/** + * Performs string reverse. + * + * @param pTransform Pointer to the <code>UBiDiTransform</code> structure. + * @param pErrorCode Pointer to the error code value. + * + * @return Whether or not this function modifies the text. Besides the return + * value, the caller should also check <code>U_SUCCESS(*pErrorCode)</code>. + */ +static UBool +action_reverse(UBiDiTransform *pTransform, UErrorCode *pErrorCode) +{ + ubidi_writeReverse(pTransform->src, pTransform->srcLength, + pTransform->dest, pTransform->destSize, + UBIDI_REORDER_DEFAULT, pErrorCode); + *pTransform->pDestLength = pTransform->srcLength; + return true; +} + +/** + * Applies a new value to the text that serves as input at the current + * processing step. This value is identical to the original one when we begin + * the processing, but usually changes as the transformation progresses. + * + * @param pTransform A pointer to the <code>UBiDiTransform</code> structure. + * @param newSrc A pointer whose value is to be used as input text. + * @param newLength A length of the new text in <code>char16_t</code>s. + * @param newSize A new source capacity in <code>char16_t</code>s. + * @param pErrorCode Pointer to the error code value. + */ +static void +updateSrc(UBiDiTransform *pTransform, const char16_t *newSrc, uint32_t newLength, + uint32_t newSize, UErrorCode *pErrorCode) +{ + if (newSize < newLength) { + *pErrorCode = U_BUFFER_OVERFLOW_ERROR; + return; + } + if (newSize > pTransform->srcSize) { + newSize += 50; // allocate slightly more than needed right now + if (pTransform->src != nullptr) { + uprv_free(pTransform->src); + pTransform->src = nullptr; + } + pTransform->src = (char16_t *)uprv_malloc(newSize * sizeof(char16_t)); + if (pTransform->src == nullptr) { + *pErrorCode = U_MEMORY_ALLOCATION_ERROR; + //pTransform->srcLength = pTransform->srcSize = 0; + return; + } + pTransform->srcSize = newSize; + } + u_strncpy(pTransform->src, newSrc, newLength); + pTransform->srcLength = u_terminateUChars(pTransform->src, + pTransform->srcSize, newLength, pErrorCode); +} + +/** + * Calls a lower level shaping function. + * + * @param pTransform Pointer to the <code>UBiDiTransform</code> structure. + * @param options Shaping options. + * @param pErrorCode Pointer to the error code value. + */ +static void +doShape(UBiDiTransform *pTransform, uint32_t options, UErrorCode *pErrorCode) +{ + *pTransform->pDestLength = u_shapeArabic(pTransform->src, + pTransform->srcLength, pTransform->dest, pTransform->destSize, + options, pErrorCode); +} + +/** + * Performs digit and letter shaping. + * + * @param pTransform Pointer to the <code>UBiDiTransform</code> structure. + * @param pErrorCode Pointer to the error code value. + * + * @return Whether or not this function modifies the text. Besides the return + * value, the caller should also check <code>U_SUCCESS(*pErrorCode)</code>. + */ +static UBool +action_shapeArabic(UBiDiTransform *pTransform, UErrorCode *pErrorCode) +{ + if ((pTransform->letters | pTransform->digits) == 0) { + return false; + } + if (pTransform->pActiveScheme->lettersDir == pTransform->pActiveScheme->digitsDir) { + doShape(pTransform, pTransform->letters | pTransform->digits | pTransform->pActiveScheme->lettersDir, + pErrorCode); + } else { + doShape(pTransform, pTransform->digits | pTransform->pActiveScheme->digitsDir, pErrorCode); + if (U_SUCCESS(*pErrorCode)) { + updateSrc(pTransform, pTransform->dest, *pTransform->pDestLength, + *pTransform->pDestLength, pErrorCode); + doShape(pTransform, pTransform->letters | pTransform->pActiveScheme->lettersDir, + pErrorCode); + } + } + return true; +} + +/** + * Performs character mirroring. + * + * @param pTransform Pointer to the <code>UBiDiTransform</code> structure. + * @param pErrorCode Pointer to the error code value. + * + * @return Whether or not this function modifies the text. Besides the return + * value, the caller should also check <code>U_SUCCESS(*pErrorCode)</code>. + */ +static UBool +action_mirror(UBiDiTransform *pTransform, UErrorCode *pErrorCode) +{ + UChar32 c; + uint32_t i = 0, j = 0; + if (0 == (pTransform->reorderingOptions & UBIDI_DO_MIRRORING)) { + return false; + } + if (pTransform->destSize < pTransform->srcLength) { + *pErrorCode = U_BUFFER_OVERFLOW_ERROR; + return false; + } + do { + UBool isOdd = ubidi_getLevelAt(pTransform->pBidi, i) & 1; + U16_NEXT(pTransform->src, i, pTransform->srcLength, c); + U16_APPEND_UNSAFE(pTransform->dest, j, isOdd ? u_charMirror(c) : c); + } while (i < pTransform->srcLength); + + *pTransform->pDestLength = pTransform->srcLength; + pTransform->reorderingOptions = UBIDI_REORDER_DEFAULT; + return true; +} + +/** + * All possible reordering schemes. + * + */ +static const ReorderingScheme Schemes[] = +{ + /* 0: Logical LTR => Visual LTR */ + {LTR, LOGICAL, LTR, VISUAL, SHAPE_LOGICAL, SHAPE_LOGICAL, LTR, + {action_shapeArabic, action_resolve, action_reorder, nullptr}}, + /* 1: Logical RTL => Visual LTR */ + {RTL, LOGICAL, LTR, VISUAL, SHAPE_LOGICAL, SHAPE_VISUAL, RTL, + {action_resolve, action_reorder, action_shapeArabic, nullptr}}, + /* 2: Logical LTR => Visual RTL */ + {LTR, LOGICAL, RTL, VISUAL, SHAPE_LOGICAL, SHAPE_LOGICAL, LTR, + {action_shapeArabic, action_resolve, action_reorder, action_reverse, nullptr}}, + /* 3: Logical RTL => Visual RTL */ + {RTL, LOGICAL, RTL, VISUAL, SHAPE_LOGICAL, SHAPE_VISUAL, RTL, + {action_resolve, action_reorder, action_shapeArabic, action_reverse, nullptr}}, + /* 4: Visual LTR => Logical RTL */ + {LTR, VISUAL, RTL, LOGICAL, SHAPE_LOGICAL, SHAPE_VISUAL, RTL, + {action_shapeArabic, action_setInverse, action_resolve, action_reorder, nullptr}}, + /* 5: Visual RTL => Logical RTL */ + {RTL, VISUAL, RTL, LOGICAL, SHAPE_LOGICAL, SHAPE_VISUAL, RTL, + {action_reverse, action_shapeArabic, action_setInverse, action_resolve, action_reorder, nullptr}}, + /* 6: Visual LTR => Logical LTR */ + {LTR, VISUAL, LTR, LOGICAL, SHAPE_LOGICAL, SHAPE_LOGICAL, LTR, + {action_setInverse, action_resolve, action_reorder, action_shapeArabic, nullptr}}, + /* 7: Visual RTL => Logical LTR */ + {RTL, VISUAL, LTR, LOGICAL, SHAPE_LOGICAL, SHAPE_LOGICAL, LTR, + {action_reverse, action_setInverse, action_resolve, action_reorder, action_shapeArabic, nullptr}}, + /* 8: Logical LTR => Logical RTL */ + {LTR, LOGICAL, RTL, LOGICAL, SHAPE_LOGICAL, SHAPE_LOGICAL, LTR, + {action_shapeArabic, action_resolve, action_mirror, action_setRunsOnly, action_resolve, action_reorder, nullptr}}, + /* 9: Logical RTL => Logical LTR */ + {RTL, LOGICAL, LTR, LOGICAL, SHAPE_LOGICAL, SHAPE_LOGICAL, RTL, + {action_resolve, action_mirror, action_setRunsOnly, action_resolve, action_reorder, action_shapeArabic, nullptr}}, + /* 10: Visual LTR => Visual RTL */ + {LTR, VISUAL, RTL, VISUAL, SHAPE_LOGICAL, SHAPE_VISUAL, LTR, + {action_shapeArabic, action_setInverse, action_resolve, action_mirror, action_reverse, nullptr}}, + /* 11: Visual RTL => Visual LTR */ + {RTL, VISUAL, LTR, VISUAL, SHAPE_LOGICAL, SHAPE_VISUAL, LTR, + {action_reverse, action_shapeArabic, action_setInverse, action_resolve, action_mirror, nullptr}}, + /* 12: Logical LTR => Logical LTR */ + {LTR, LOGICAL, LTR, LOGICAL, SHAPE_LOGICAL, SHAPE_LOGICAL, LTR, + {action_resolve, action_mirror, action_shapeArabic, nullptr}}, + /* 13: Logical RTL => Logical RTL */ + {RTL, LOGICAL, RTL, LOGICAL, SHAPE_VISUAL, SHAPE_LOGICAL, RTL, + {action_resolve, action_mirror, action_shapeArabic, nullptr}}, + /* 14: Visual LTR => Visual LTR */ + {LTR, VISUAL, LTR, VISUAL, SHAPE_LOGICAL, SHAPE_VISUAL, LTR, + {action_resolve, action_mirror, action_shapeArabic, nullptr}}, + /* 15: Visual RTL => Visual RTL */ + {RTL, VISUAL, RTL, VISUAL, SHAPE_LOGICAL, SHAPE_VISUAL, LTR, + {action_reverse, action_resolve, action_mirror, action_shapeArabic, action_reverse, nullptr}} +}; + +static const uint32_t nSchemes = sizeof(Schemes) / sizeof(*Schemes); + +/** + * When the direction option is <code>UBIDI_DEFAULT_LTR</code> or + * <code>UBIDI_DEFAULT_RTL</code>, resolve the base direction according to that + * of the first strong bidi character. + */ +static void +resolveBaseDirection(const char16_t *text, uint32_t length, + UBiDiLevel *pInLevel, UBiDiLevel *pOutLevel) +{ + switch (*pInLevel) { + case UBIDI_DEFAULT_LTR: + case UBIDI_DEFAULT_RTL: { + UBiDiLevel level = static_cast<UBiDiLevel>(ubidi_getBaseDirection(text, length)); + *pInLevel = static_cast<UBiDiLevel>(level != UBIDI_NEUTRAL) ? level + : *pInLevel == UBIDI_DEFAULT_RTL ? static_cast<UBiDiLevel>(RTL) : static_cast<UBiDiLevel>(LTR); + break; + } + default: + *pInLevel &= 1; + break; + } + switch (*pOutLevel) { + case UBIDI_DEFAULT_LTR: + case UBIDI_DEFAULT_RTL: + *pOutLevel = *pInLevel; + break; + default: + *pOutLevel &= 1; + break; + } +} + +/** + * Finds a valid <code>ReorderingScheme</code> matching the + * caller-defined scheme. + * + * @return A valid <code>ReorderingScheme</code> object or nullptr + */ +static const ReorderingScheme* +findMatchingScheme(UBiDiLevel inLevel, UBiDiLevel outLevel, + UBiDiOrder inOrder, UBiDiOrder outOrder) +{ + uint32_t i; + for (i = 0; i < nSchemes; i++) { + const ReorderingScheme *pScheme = Schemes + i; + if (inLevel == pScheme->inLevel && outLevel == pScheme->outLevel + && inOrder == pScheme->inOrder && outOrder == pScheme->outOrder) { + return pScheme; + } + } + return nullptr; +} + +U_CAPI uint32_t U_EXPORT2 +ubiditransform_transform(UBiDiTransform *pBiDiTransform, + const char16_t *src, int32_t srcLength, + char16_t *dest, int32_t destSize, + UBiDiLevel inParaLevel, UBiDiOrder inOrder, + UBiDiLevel outParaLevel, UBiDiOrder outOrder, + UBiDiMirroring doMirroring, uint32_t shapingOptions, + UErrorCode *pErrorCode) +{ + uint32_t destLength = 0; + UBool textChanged = false; + const UBiDiTransform *pOrigTransform = pBiDiTransform; + const UBiDiAction *action = nullptr; + + if (U_FAILURE(*pErrorCode)) { + return 0; + } + if (src == nullptr || dest == nullptr) { + *pErrorCode = U_ILLEGAL_ARGUMENT_ERROR; + return 0; + } + CHECK_LEN(src, srcLength, pErrorCode); + CHECK_LEN(dest, destSize, pErrorCode); + + if (pBiDiTransform == nullptr) { + pBiDiTransform = ubiditransform_open(pErrorCode); + if (U_FAILURE(*pErrorCode)) { + return 0; + } + } + /* Current limitation: in multiple paragraphs will be resolved according + to the 1st paragraph */ + resolveBaseDirection(src, srcLength, &inParaLevel, &outParaLevel); + + pBiDiTransform->pActiveScheme = findMatchingScheme(inParaLevel, outParaLevel, + inOrder, outOrder); + if (pBiDiTransform->pActiveScheme == nullptr) { + goto cleanup; + } + pBiDiTransform->reorderingOptions = doMirroring ? UBIDI_DO_MIRRORING + : UBIDI_REORDER_DEFAULT; + + /* Ignore TEXT_DIRECTION_* flags, as we apply our own depending on the text + scheme at the time shaping is invoked. */ + shapingOptions &= ~U_SHAPE_TEXT_DIRECTION_MASK; + pBiDiTransform->digits = shapingOptions & ~U_SHAPE_LETTERS_MASK; + pBiDiTransform->letters = shapingOptions & ~U_SHAPE_DIGITS_MASK; + + updateSrc(pBiDiTransform, src, srcLength, destSize > srcLength ? destSize : srcLength, pErrorCode); + if (U_FAILURE(*pErrorCode)) { + goto cleanup; + } + if (pBiDiTransform->pBidi == nullptr) { + pBiDiTransform->pBidi = ubidi_openSized(0, 0, pErrorCode); + if (U_FAILURE(*pErrorCode)) { + goto cleanup; + } + } + pBiDiTransform->dest = dest; + pBiDiTransform->destSize = destSize; + pBiDiTransform->pDestLength = &destLength; + + /* Checking for U_SUCCESS() within the loop to bail out on first failure. */ + for (action = pBiDiTransform->pActiveScheme->actions; *action && U_SUCCESS(*pErrorCode); action++) { + if ((*action)(pBiDiTransform, pErrorCode)) { + if (action + 1) { + updateSrc(pBiDiTransform, pBiDiTransform->dest, *pBiDiTransform->pDestLength, + *pBiDiTransform->pDestLength, pErrorCode); + } + textChanged = true; + } + } + ubidi_setInverse(pBiDiTransform->pBidi, false); + + if (!textChanged && U_SUCCESS(*pErrorCode)) { + /* Text was not changed - just copy src to dest */ + if (destSize < srcLength) { + *pErrorCode = U_BUFFER_OVERFLOW_ERROR; + } else { + u_strncpy(dest, src, srcLength); + destLength = srcLength; + } + } +cleanup: + if (pOrigTransform != pBiDiTransform) { + ubiditransform_close(pBiDiTransform); + } else { + pBiDiTransform->dest = nullptr; + pBiDiTransform->pDestLength = nullptr; + pBiDiTransform->srcLength = 0; + pBiDiTransform->destSize = 0; + } + return U_FAILURE(*pErrorCode) ? 0 : destLength; +} |