Source/WebCore/layout/integration/InlineIteratorBoxModernPath.h

/*
 * Copyright (C) 2019 Apple Inc. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY APPLE INC. AND ITS CONTRIBUTORS ``AS IS''
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
 * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR ITS CONTRIBUTORS
 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
 * THE POSSIBILITY OF SUCH DAMAGE.
 */

#pragma once

#if ENABLE(LAYOUT_FORMATTING_CONTEXT)

#include "FontCascade.h"
#include "LayoutContainerBox.h"
#include "LayoutIntegrationInlineContent.h"
#include "TextBoxSelectableRange.h"

namespace WebCore {
namespace InlineIterator {

class BoxModernPath {
public:
    BoxModernPath(const LayoutIntegration::InlineContent& inlineContent)
        : m_inlineContent(&inlineContent)
    {
        setAtEnd();
    }
    BoxModernPath(const LayoutIntegration::InlineContent& inlineContent, size_t startIndex)
        : m_inlineContent(&inlineContent)
        , m_boxIndex(startIndex)
    {
    }

    bool isText() const { return box().isTextOrSoftLineBreak(); }
    bool isInlineBox() const { return box().isInlineBox(); }
    bool isRootInlineBox() const { return box().isRootInlineBox(); }

    FloatRect rect() const { return box().rect(); }

    bool isHorizontal() const { return box().isHorizontal(); }
    bool isLineBreak() const { return box().isLineBreak(); }

    unsigned minimumCaretOffset() const { return isText() ? start() : 0; }
    unsigned maximumCaretOffset() const { return isText() ? end() : 1; }

    unsigned char bidiLevel() const { return box().bidiLevel(); }

    bool hasHyphen() const { return box().text()->hasHyphen(); }
    StringView text() const { return box().text()->originalContent(); }
    unsigned start() const { return box().text()->start(); }
    unsigned end() const { return box().text()->end(); }
    unsigned length() const { return box().text()->length(); }

    TextBoxSelectableRange selectableRange() const
    {
        return {
            start(),
            length(),
            box().text()->hasHyphen() ? box().style().hyphenString().length() : 0,
            box().isLineBreak()
        };
    }

    TextRun createTextRun(CreateTextRunMode mode) const
    {
        auto& style = box().style();
        auto expansion = box().expansion();
        auto rect = this->rect();
        auto xPos = rect.x() - (line().lineBoxLeft() + line().contentLeft());

        auto textForRun = [&] {
            if (mode == CreateTextRunMode::Editing || !hasHyphen())
                return text().toStringWithoutCopying();

            return makeString(text(), style.hyphenString());
        }();

        bool characterScanForCodePath = !renderText().canUseSimpleFontCodePath();
        TextRun textRun { textForRun, xPos, expansion.horizontalExpansion, expansion.behavior, direction(), style.rtlOrdering() == Order::Visual, characterScanForCodePath };
        textRun.setTabSize(!style.collapseWhiteSpace(), style.tabSize());
        return textRun;
    };

    const RenderObject& renderer() const
    {
        return m_inlineContent->rendererForLayoutBox(box().layoutBox());
    }

    void traverseNextTextBox()
    {
        ASSERT(!atEnd());
        ASSERT(box().isTextOrSoftLineBreak());

        if (box().isLastForLayoutBox()) {
            setAtEnd();
            return;
        }

        traverseNextWithSameLayoutBox();

        ASSERT(box().isTextOrSoftLineBreak());
    }

    void traverseNextOnLine()
    {
        ASSERT(!atEnd());

        auto oldLineIndex = box().lineIndex();

        traverseNextLeaf();

        if (!atEnd() && oldLineIndex != box().lineIndex())
            setAtEnd();
    }

    void traversePreviousOnLine()
    {
        ASSERT(!atEnd());

        auto oldLineIndex = box().lineIndex();

        traversePreviousLeaf();

        if (!atEnd() && oldLineIndex != box().lineIndex())
            setAtEnd();
    }

    void traverseNextInlineBox()
    {
        ASSERT(!atEnd());
        ASSERT(box().isInlineBox());

        if (box().isLastForLayoutBox()) {
            setAtEnd();
            return;
        }

        traverseNextWithSameLayoutBox();

        ASSERT(box().isInlineBox());
    }

    void traversePreviousInlineBox()
    {
        ASSERT(!atEnd());
        ASSERT(box().isInlineBox());

        if (box().isFirstForLayoutBox()) {
            setAtEnd();
            return;
        }

        traversePreviousWithSameLayoutBox();

        ASSERT(box().isInlineBox());
    }

    BoxModernPath firstLeafBoxForInlineBox() const
    {
        ASSERT(box().isInlineBox());

        auto& inlineBox = box().layoutBox();

        // The next box is the first descendant of this box;
        auto first = *this;
        first.traverseNextOnLine();

        if (!first.atEnd() && !first.isWithinInlineBox(inlineBox))
            first.setAtEnd();

        return first;
    }

    BoxModernPath lastLeafBoxForInlineBox() const
    {
        ASSERT(box().isInlineBox());

        auto& inlineBox = box().layoutBox();

        // FIXME: Get the last box index directly from the display box.
        auto last = firstLeafBoxForInlineBox();
        for (auto box = last; !box.atEnd() && box.isWithinInlineBox(inlineBox); box.traverseNextOnLine())
            last = box;

        return last;
    }

    bool operator==(const BoxModernPath& other) const { return m_inlineContent == other.m_inlineContent && m_boxIndex == other.m_boxIndex; }

    bool atEnd() const { return m_boxIndex == boxes().size(); }
    const InlineDisplay::Box& box() const { return boxes()[m_boxIndex]; }
    auto& inlineContent() const { return *m_inlineContent; }

private:
    bool isWithinInlineBox(const Layout::Box& inlineBox)
    {
        auto* layoutBox = &box().layoutBox().parent();
        for (; layoutBox->isInlineBox(); layoutBox = &layoutBox->parent()) {
            if (layoutBox == &inlineBox)
                return true;
        }
        return false;
    }

    void traverseNextBox()
    {
        ASSERT(!atEnd());
        ++m_boxIndex;
    }

    void traversePreviousBox()
    {
        ASSERT(!atEnd());
        m_boxIndex = m_boxIndex ? m_boxIndex - 1 : boxes().size();
    }

    void traverseNextLeaf()
    {
        do {
            traverseNextBox();
        } while (!atEnd() && box().isInlineBox());
    }

    void traversePreviousLeaf()
    {
        do {
            traversePreviousBox();
        } while (!atEnd() && box().isInlineBox());
    }

    void traverseNextWithSameLayoutBox()
    {
        auto& layoutBox = box().layoutBox();
        do {
            traverseNextBox();
        } while (!atEnd() && &box().layoutBox() != &layoutBox);
    }

    void traversePreviousWithSameLayoutBox()
    {
        auto& layoutBox = box().layoutBox();
        do {
            traversePreviousBox();
        } while (!atEnd() && &box().layoutBox() != &layoutBox);
    }

    void setAtEnd() { m_boxIndex = boxes().size(); }

    const LayoutIntegration::InlineContent::Boxes& boxes() const { return m_inlineContent->boxes; }
    const LayoutIntegration::Line& line() const { return m_inlineContent->lineForBox(box()); }

    const RenderText& renderText() const { return downcast<RenderText>(renderer()); }
    TextDirection direction() const { return bidiLevel() % 2 ? TextDirection::RTL : TextDirection::LTR; }

    RefPtr<const LayoutIntegration::InlineContent> m_inlineContent;
    size_t m_boxIndex { 0 };
};

}
}

#endif