/**
* 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;
}
std::u16string BiDi::writeReverse(const std::u16string& input, std::size_t logicalStart, std::size_t logicalEnd) {
UErrorCode errorCode = U_ZERO_ERROR;
int32_t logicalLength = static_cast<int32_t>(logicalEnd - logicalStart);
std::u16string outputText(logicalLength + 1, 0);
// UBIDI_DO_MIRRORING: Apply unicode mirroring of characters like parentheses
// UBIDI_REMOVE_BIDI_CONTROLS: Now that all the lines are set, remove control characters so that
// they don't show up on screen (some fonts have glyphs representing them)
int32_t outputLength =
ubidi_writeReverse(mbgl::utf16char_cast<const UChar*>(&input[logicalStart]),
logicalLength,
mbgl::utf16char_cast<UChar*>(&outputText[0]),
logicalLength + 1, // Extra room for null terminator, although we don't really need to have ICU write it for us
UBIDI_DO_MIRRORING | UBIDI_REMOVE_BIDI_CONTROLS,
&errorCode);
if (U_FAILURE(errorCode)) {
throw std::runtime_error(std::string("BiDi::writeReverse: ") + u_errorName(errorCode));
}
outputText.resize(outputLength); // REMOVE_BIDI_CONTROLS may have shrunk the string
return outputText;
}
