flutter_flutter/engine/core/rendering/TextRunConstructor.cpp

/*
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#include "sky/engine/core/rendering/TextRunConstructor.h"

#include "sky/engine/core/rendering/RenderText.h"
#include "sky/engine/core/rendering/style/RenderStyle.h"
#include "sky/engine/platform/text/BidiTextRun.h"

namespace blink {

template <typename CharacterType>
static inline TextRun constructTextRunInternal(RenderObject* context, const Font& font, const CharacterType* characters, int length, RenderStyle* style, TextDirection direction, TextRun::ExpansionBehavior expansion)
{
    ASSERT(style);

    bool directionalOverride = style->rtlOrdering() == VisualOrder;
    return TextRun(characters, length, 0, 0, expansion, direction, directionalOverride);
}

template <typename CharacterType>
static inline TextRun constructTextRunInternal(RenderObject* context, const Font& font, const CharacterType* characters, int length, RenderStyle* style, TextDirection direction, TextRun::ExpansionBehavior expansion, TextRunFlags flags)
{
    ASSERT(style);

    TextDirection textDirection = direction;
    bool directionalOverride = style->rtlOrdering() == VisualOrder;
    if (flags != DefaultTextRunFlags) {
        if (flags & RespectDirection)
            textDirection = style->direction();
        if (flags & RespectDirectionOverride)
            directionalOverride |= isOverride(style->unicodeBidi());
    }

    return TextRun(characters, length, 0, 0, expansion, textDirection, directionalOverride);
}

TextRun constructTextRun(RenderObject* context, const Font& font, const LChar* characters, int length, RenderStyle* style, TextDirection direction, TextRun::ExpansionBehavior expansion)
{
    return constructTextRunInternal(context, font, characters, length, style, direction, expansion);
}

TextRun constructTextRun(RenderObject* context, const Font& font, const UChar* characters, int length, RenderStyle* style, TextDirection direction, TextRun::ExpansionBehavior expansion)
{
    return constructTextRunInternal(context, font, characters, length, style, direction, expansion);
}

TextRun constructTextRun(RenderObject* context, const Font& font, const RenderText* text, RenderStyle* style, TextDirection direction, TextRun::ExpansionBehavior expansion)
{
    if (text->is8Bit())
        return constructTextRunInternal(context, font, text->characters8(), text->textLength(), style, direction, expansion);
    return constructTextRunInternal(context, font, text->characters16(), text->textLength(), style, direction, expansion);
}

TextRun constructTextRun(RenderObject* context, const Font& font, const RenderText* text, unsigned offset, unsigned length, RenderStyle* style, TextDirection direction, TextRun::ExpansionBehavior expansion)
{
    ASSERT(offset + length <= text->textLength());
    if (text->is8Bit())
        return constructTextRunInternal(context, font, text->characters8() + offset, length, style, direction, expansion);
    return constructTextRunInternal(context, font, text->characters16() + offset, length, style, direction, expansion);
}

TextRun constructTextRun(RenderObject* context, const Font& font, const String& string, RenderStyle* style, TextDirection direction, TextRun::ExpansionBehavior expansion, TextRunFlags flags)
{
    unsigned length = string.length();
    if (!length)
        return constructTextRunInternal(context, font, static_cast<const LChar*>(0), length, style, direction, expansion, flags);
    if (string.is8Bit())
        return constructTextRunInternal(context, font, string.characters8(), length, style, direction, expansion, flags);
    return constructTextRunInternal(context, font, string.characters16(), length, style, direction, expansion, flags);
}

TextRun constructTextRun(RenderObject* context, const Font& font, const String& string, RenderStyle* style, TextRun::ExpansionBehavior expansion, TextRunFlags flags)
{
    bool hasStrongDirectionality;
    return constructTextRun(context, font, string, style, determineDirectionality(string, hasStrongDirectionality), expansion, flags);
}

TextRun constructTextRun(RenderObject* context, const Font& font, const RenderText* text, unsigned offset, unsigned length, RenderStyle* style, TextRun::ExpansionBehavior expansion)
{
    ASSERT(offset + length <= text->textLength());
    TextRun run = text->is8Bit()
        ? constructTextRunInternal(context, font, text->characters8() + offset, length, style, LTR, expansion)
        : constructTextRunInternal(context, font, text->characters16() + offset, length, style, LTR, expansion);
    bool hasStrongDirectionality;
    run.setDirection(directionForRun(run, hasStrongDirectionality));
    return run;
}

} // namespace blink