third_party/WebKit/Source/platform/text/BidiTextRun.cpp

/*
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#include "platform/text/BidiTextRun.h"

#include "platform/text/BidiResolver.h"
#include "platform/text/TextRunIterator.h"

namespace blink {

TextDirection directionForRun(TextRun& run, bool* hasStrongDirectionality) {
  if (!hasStrongDirectionality) {
    // 8bit is Latin-1 and therefore is always LTR.
    if (run.is8Bit())
      return TextDirection::Ltr;

    // length == 1 for more than 90% of cases of width() for CJK text.
    if (run.length() == 1 && U16_IS_SINGLE(run.characters16()[0]))
      return directionForCharacter(run.characters16()[0]);
  }

  BidiResolver<TextRunIterator, BidiCharacterRun> bidiResolver;
  bidiResolver.setStatus(
      BidiStatus(run.direction(), run.directionalOverride()));
  bidiResolver.setPositionIgnoringNestedIsolates(TextRunIterator(&run, 0));
  return bidiResolver.determineDirectionality(hasStrongDirectionality);
}

TextDirection determineDirectionality(const String& value,
                                      bool* hasStrongDirectionality) {
  TextRun run(value);
  return directionForRun(run, hasStrongDirectionality);
}

TextRun textRunWithDirectionality(const String& value,
                                  bool* hasStrongDirectionality) {
  TextRun run(value);
  TextDirection direction = directionForRun(run, hasStrongDirectionality);
  if (hasStrongDirectionality)
    run.setDirection(direction);
  return run;
}

}  // namespace blink