sky/engine/core/rendering/line/LineWidth.cpp

/*
 * Copyright (C) 2013 Adobe Systems Incorporated. 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 THE COPYRIGHT HOLDERS AND 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 THE
 * COPYRIGHT HOLDER OR 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
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#include "sky/engine/core/rendering/line/LineWidth.h"

#include "sky/engine/core/rendering/RenderBlock.h"
#include "sky/engine/core/rendering/RenderParagraph.h"

namespace blink {

LineWidth::LineWidth(RenderParagraph& block, bool isFirstLine, IndentTextOrNot shouldIndentText)
    : m_block(block)
    , m_uncommittedWidth(0)
    , m_committedWidth(0)
    , m_trailingWhitespaceWidth(0)
    , m_left(0)
    , m_right(0)
    , m_availableWidth(0)
    , m_shouldIndentText(shouldIndentText)
{
    updateAvailableWidth();
}

void LineWidth::updateAvailableWidth()
{
    m_left = m_block.logicalLeftOffsetForLine(shouldIndentText()).toFloat();
    m_right = m_block.logicalRightOffsetForLine(shouldIndentText()).toFloat();
    computeAvailableWidthFromLeftAndRight();
}

void LineWidth::commit()
{
    m_committedWidth += m_uncommittedWidth;
    m_uncommittedWidth = 0;
}

void LineWidth::updateLineDimension(LayoutUnit newLineTop, LayoutUnit newLineWidth, const float& newLineLeft, const float& newLineRight)
{
    if (newLineWidth <= m_availableWidth)
        return;

    m_block.setLogicalHeight(newLineTop);
    m_availableWidth = newLineWidth.toFloat();
    m_left = newLineLeft;
    m_right = newLineRight;
}


void LineWidth::fitBelowFloats(bool isFirstLine)
{
    ASSERT(!m_committedWidth);
    ASSERT(!fitsOnLine());

    LayoutUnit floatLogicalBottom;
    LayoutUnit lastFloatLogicalBottom = m_block.logicalHeight();
    float newLineWidth = m_availableWidth;
    float newLineLeft = m_left;
    float newLineRight = m_right;

    while (true) {
        floatLogicalBottom = lastFloatLogicalBottom;
        if (floatLogicalBottom <= lastFloatLogicalBottom)
            break;

        newLineLeft = m_block.logicalLeftOffsetForLine(shouldIndentText()).toFloat();
        newLineRight = m_block.logicalRightOffsetForLine(shouldIndentText()).toFloat();
        newLineWidth = std::max(0.0f, newLineRight - newLineLeft);

        lastFloatLogicalBottom = floatLogicalBottom;

        if (newLineWidth >= m_uncommittedWidth)
            break;
    }
    updateLineDimension(lastFloatLogicalBottom, newLineWidth, newLineLeft, newLineRight);
}

void LineWidth::computeAvailableWidthFromLeftAndRight()
{
    m_availableWidth = max(0.0f, m_right - m_left);
}

}