Source/WebCore/layout/integration/InlineIteratorTextBox.h

/*
 * Copyright (C) 2019-2021 Apple Inc. All rights reserved.
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 * Redistribution and use in source and binary forms, with or without
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 */

#pragma once

#include "InlineIteratorBox.h"
#include "RenderText.h"

namespace WebCore {

namespace InlineIterator {

class TextBox : public Box {
public:
    TextBox(PathVariant&&);

    bool hasHyphen() const;
    StringView text() const;

    unsigned start() const;
    unsigned end() const;
    unsigned length() const;

    unsigned offsetForPosition(float x, bool includePartialGlyphs = true) const;
    float positionForOffset(unsigned) const;

    TextBoxSelectableRange selectableRange() const;
    LayoutRect selectionRect(unsigned start, unsigned end) const;

    bool isCombinedText() const;
    const FontCascade& fontCascade() const;

    TextRun createTextRun(CreateTextRunMode = CreateTextRunMode::Painting) const;

    const RenderText& renderer() const { return downcast<RenderText>(Box::renderer()); }

    // FIXME: Remove. For intermediate porting steps only.
    const LegacyInlineTextBox* legacyInlineBox() const { return downcast<LegacyInlineTextBox>(Box::legacyInlineBox()); }

    // This returns the next text box generated for the same RenderText/Layout::InlineTextBox.
    TextBoxIterator nextTextBox() const;
};

class TextBoxIterator : public LeafBoxIterator {
public:
    TextBoxIterator() { }
    TextBoxIterator(Box::PathVariant&&);
    TextBoxIterator(const Box&);

    TextBoxIterator& operator++() { return traverseNextTextBox(); }

    const TextBox& operator*() const { return get(); }
    const TextBox* operator->() const { return &get(); }

    // This traverses to the next text box generated for the same RenderText/Layout::InlineTextBox.
    TextBoxIterator& traverseNextTextBox();

private:
    BoxIterator& traverseNextOnLine() = delete;
    BoxIterator& traversePreviousOnLine() = delete;
    BoxIterator& traverseNextOnLineIgnoringLineBreak() = delete;
    BoxIterator& traversePreviousOnLineIgnoringLineBreak() = delete;

    const TextBox& get() const { return downcast<TextBox>(m_box); }
};

class TextBoxRange {
public:
    TextBoxRange(TextBoxIterator begin)
        : m_begin(begin)
    {
    }

    TextBoxIterator begin() const { return m_begin; }
    EndIterator end() const { return { }; }

private:
    TextBoxIterator m_begin;
};

TextBoxIterator firstTextBoxFor(const RenderText&);
TextBoxIterator textBoxFor(const LegacyInlineTextBox*);
#if ENABLE(LAYOUT_FORMATTING_CONTEXT)
TextBoxIterator textBoxFor(const LayoutIntegration::InlineContent&, const InlineDisplay::Box&);
TextBoxIterator textBoxFor(const LayoutIntegration::InlineContent&, size_t boxIndex);
#endif
TextBoxRange textBoxesFor(const RenderText&);

inline bool TextBox::hasHyphen() const
{
    return WTF::switchOn(m_pathVariant, [](auto& path) {
        return path.hasHyphen();
    });
}

inline TextBox::TextBox(PathVariant&& path)
    : Box(WTFMove(path))
{
}

inline StringView TextBox::text() const
{
    return WTF::switchOn(m_pathVariant, [](auto& path) {
        return path.text();
    });
}

inline unsigned TextBox::start() const
{
    return WTF::switchOn(m_pathVariant, [](auto& path) {
        return path.start();
    });
}

inline unsigned TextBox::end() const
{
    return WTF::switchOn(m_pathVariant, [](auto& path) {
        return path.end();
    });
}

inline unsigned TextBox::length() const
{
    return WTF::switchOn(m_pathVariant, [](auto& path) {
        return path.length();
    });
}

inline TextBoxSelectableRange TextBox::selectableRange() const
{
    return WTF::switchOn(m_pathVariant, [&](auto& path) {
        return path.selectableRange();
    });
}

inline TextRun TextBox::createTextRun(CreateTextRunMode mode) const
{
    return WTF::switchOn(m_pathVariant, [&](auto& path) {
        return path.createTextRun(mode);
    });
}

}
}

SPECIALIZE_TYPE_TRAITS_BEGIN(WebCore::InlineIterator::TextBox)
static bool isType(const WebCore::InlineIterator::Box& box) { return box.isText(); }
SPECIALIZE_TYPE_TRAITS_END()

SPECIALIZE_TYPE_TRAITS_BEGIN(WebCore::InlineIterator::TextBoxIterator)
static bool isType(const WebCore::InlineIterator::BoxIterator& box) { return !box || box->isText(); }
SPECIALIZE_TYPE_TRAITS_END()