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      1 /*
      2  * Copyright (C) 2013 Adobe Systems Incorporated. All rights reserved.
      3  *
      4  * Redistribution and use in source and binary forms, with or without
      5  * modification, are permitted provided that the following conditions
      6  * are met:
      7  *
      8  * 1. Redistributions of source code must retain the above
      9  *    copyright notice, this list of conditions and the following
     10  *    disclaimer.
     11  * 2. Redistributions in binary form must reproduce the above
     12  *    copyright notice, this list of conditions and the following
     13  *    disclaimer in the documentation and/or other materials
     14  *    provided with the distribution.
     15  *
     16  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
     17  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
     18  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
     19  * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
     20  * COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
     21  * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
     22  * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
     23  * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
     25  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
     26  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
     27  * OF THE POSSIBILITY OF SUCH DAMAGE.
     28  */
     29 
     30 #include "config.h"
     31 #include "core/rendering/line/LineWidth.h"
     32 
     33 #include "core/rendering/RenderBlock.h"
     34 #include "core/rendering/RenderRubyRun.h"
     35 
     36 namespace blink {
     37 
     38 LineWidth::LineWidth(RenderBlockFlow& block, bool isFirstLine, IndentTextOrNot shouldIndentText)
     39     : m_block(block)
     40     , m_uncommittedWidth(0)
     41     , m_committedWidth(0)
     42     , m_overhangWidth(0)
     43     , m_trailingWhitespaceWidth(0)
     44     , m_left(0)
     45     , m_right(0)
     46     , m_availableWidth(0)
     47     , m_isFirstLine(isFirstLine)
     48     , m_shouldIndentText(shouldIndentText)
     49 {
     50     updateAvailableWidth();
     51 }
     52 
     53 void LineWidth::updateAvailableWidth(LayoutUnit replacedHeight)
     54 {
     55     LayoutUnit height = m_block.logicalHeight();
     56     LayoutUnit logicalHeight = m_block.minLineHeightForReplacedRenderer(m_isFirstLine, replacedHeight);
     57     m_left = m_block.logicalLeftOffsetForLine(height, shouldIndentText(), logicalHeight).toFloat();
     58     m_right = m_block.logicalRightOffsetForLine(height, shouldIndentText(), logicalHeight).toFloat();
     59 
     60     computeAvailableWidthFromLeftAndRight();
     61 }
     62 
     63 void LineWidth::shrinkAvailableWidthForNewFloatIfNeeded(FloatingObject* newFloat)
     64 {
     65     LayoutUnit height = m_block.logicalHeight();
     66     if (height < m_block.logicalTopForFloat(newFloat) || height >= m_block.logicalBottomForFloat(newFloat))
     67         return;
     68 
     69     ShapeOutsideDeltas shapeDeltas;
     70     if (ShapeOutsideInfo* shapeOutsideInfo = newFloat->renderer()->shapeOutsideInfo()) {
     71         LayoutUnit lineHeight = m_block.lineHeight(m_isFirstLine, m_block.isHorizontalWritingMode() ? HorizontalLine : VerticalLine, PositionOfInteriorLineBoxes);
     72         shapeDeltas = shapeOutsideInfo->computeDeltasForContainingBlockLine(m_block, *newFloat, m_block.logicalHeight(), lineHeight);
     73     }
     74 
     75     if (newFloat->type() == FloatingObject::FloatLeft) {
     76         float newLeft = m_block.logicalRightForFloat(newFloat).toFloat();
     77         if (shapeDeltas.isValid()) {
     78             if (shapeDeltas.lineOverlapsShape())
     79                 newLeft += shapeDeltas.rightMarginBoxDelta();
     80             else // Per the CSS Shapes spec, If the line doesn't overlap the shape, then ignore this shape for this line.
     81                 newLeft = m_left;
     82         }
     83         if (shouldIndentText() && m_block.style()->isLeftToRightDirection())
     84             newLeft += floorToInt(m_block.textIndentOffset());
     85         m_left = std::max<float>(m_left, newLeft);
     86     } else {
     87         float newRight = m_block.logicalLeftForFloat(newFloat).toFloat();
     88         if (shapeDeltas.isValid()) {
     89             if (shapeDeltas.lineOverlapsShape())
     90                 newRight += shapeDeltas.leftMarginBoxDelta();
     91             else // Per the CSS Shapes spec, If the line doesn't overlap the shape, then ignore this shape for this line.
     92                 newRight = m_right;
     93         }
     94         if (shouldIndentText() && !m_block.style()->isLeftToRightDirection())
     95             newRight -= floorToInt(m_block.textIndentOffset());
     96         m_right = std::min<float>(m_right, newRight);
     97     }
     98 
     99     computeAvailableWidthFromLeftAndRight();
    100 }
    101 
    102 void LineWidth::commit()
    103 {
    104     m_committedWidth += m_uncommittedWidth;
    105     m_uncommittedWidth = 0;
    106 }
    107 
    108 void LineWidth::applyOverhang(RenderRubyRun* rubyRun, RenderObject* startRenderer, RenderObject* endRenderer)
    109 {
    110     int startOverhang;
    111     int endOverhang;
    112     rubyRun->getOverhang(m_isFirstLine, startRenderer, endRenderer, startOverhang, endOverhang);
    113 
    114     startOverhang = std::min<int>(startOverhang, m_committedWidth);
    115     m_availableWidth += startOverhang;
    116 
    117     endOverhang = std::max(std::min<int>(endOverhang, m_availableWidth - currentWidth()), 0);
    118     m_availableWidth += endOverhang;
    119     m_overhangWidth += startOverhang + endOverhang;
    120 }
    121 
    122 inline static float availableWidthAtOffset(const RenderBlockFlow& block, const LayoutUnit& offset, bool shouldIndentText, float& newLineLeft, float& newLineRight)
    123 {
    124     newLineLeft = block.logicalLeftOffsetForLine(offset, shouldIndentText).toFloat();
    125     newLineRight = block.logicalRightOffsetForLine(offset, shouldIndentText).toFloat();
    126     return std::max(0.0f, newLineRight - newLineLeft);
    127 }
    128 
    129 inline static float availableWidthAtOffset(const RenderBlockFlow& block, const LayoutUnit& offset, bool shouldIndentText)
    130 {
    131     float newLineLeft = block.logicalLeftOffsetForLine(offset, shouldIndentText).toFloat();
    132     float newLineRight = block.logicalRightOffsetForLine(offset, shouldIndentText).toFloat();
    133     return std::max(0.0f, newLineRight - newLineLeft);
    134 }
    135 
    136 void LineWidth::updateLineDimension(LayoutUnit newLineTop, LayoutUnit newLineWidth, const float& newLineLeft, const float& newLineRight)
    137 {
    138     if (newLineWidth <= m_availableWidth)
    139         return;
    140 
    141     m_block.setLogicalHeight(newLineTop);
    142     m_availableWidth = newLineWidth + m_overhangWidth;
    143     m_left = newLineLeft;
    144     m_right = newLineRight;
    145 }
    146 
    147 inline static bool isWholeLineFit(const RenderBlockFlow& block, const LayoutUnit& lineTop, LayoutUnit lineHeight, float uncommittedWidth, bool shouldIndentText)
    148 {
    149     for (LayoutUnit lineBottom = lineTop; lineBottom <= lineTop + lineHeight; lineBottom++) {
    150         LayoutUnit availableWidthAtBottom = availableWidthAtOffset(block, lineBottom, shouldIndentText);
    151         if (availableWidthAtBottom < uncommittedWidth)
    152             return false;
    153     }
    154     return true;
    155 }
    156 
    157 void LineWidth::wrapNextToShapeOutside(bool isFirstLine)
    158 {
    159     LayoutUnit lineHeight = m_block.lineHeight(isFirstLine, m_block.isHorizontalWritingMode() ? HorizontalLine : VerticalLine, PositionOfInteriorLineBoxes);
    160     LayoutUnit lineLogicalTop = m_block.logicalHeight();
    161     LayoutUnit newLineTop = lineLogicalTop;
    162     LayoutUnit floatLogicalBottom = m_block.nextFloatLogicalBottomBelow(lineLogicalTop);
    163 
    164     float newLineWidth;
    165     float newLineLeft = m_left;
    166     float newLineRight = m_right;
    167     while (true) {
    168         newLineWidth = availableWidthAtOffset(m_block, newLineTop, shouldIndentText(), newLineLeft, newLineRight);
    169         if (newLineWidth >= m_uncommittedWidth && isWholeLineFit(m_block, newLineTop, lineHeight, m_uncommittedWidth, shouldIndentText()))
    170             break;
    171 
    172         if (newLineTop >= floatLogicalBottom)
    173             break;
    174 
    175         newLineTop++;
    176     }
    177     updateLineDimension(newLineTop, newLineWidth, newLineLeft, newLineRight);
    178 }
    179 
    180 void LineWidth::fitBelowFloats(bool isFirstLine)
    181 {
    182     ASSERT(!m_committedWidth);
    183     ASSERT(!fitsOnLine());
    184 
    185     LayoutUnit floatLogicalBottom;
    186     LayoutUnit lastFloatLogicalBottom = m_block.logicalHeight();
    187     float newLineWidth = m_availableWidth;
    188     float newLineLeft = m_left;
    189     float newLineRight = m_right;
    190 
    191     FloatingObject* lastFloatFromPreviousLine = (m_block.containsFloats() ? m_block.m_floatingObjects->set().last().get() : 0);
    192         if (lastFloatFromPreviousLine && lastFloatFromPreviousLine->renderer()->shapeOutsideInfo())
    193             return wrapNextToShapeOutside(isFirstLine);
    194 
    195     while (true) {
    196         floatLogicalBottom = m_block.nextFloatLogicalBottomBelow(lastFloatLogicalBottom, ShapeOutsideFloatShapeOffset);
    197         if (floatLogicalBottom <= lastFloatLogicalBottom)
    198             break;
    199 
    200         newLineWidth = availableWidthAtOffset(m_block, floatLogicalBottom, shouldIndentText(), newLineLeft, newLineRight);
    201         lastFloatLogicalBottom = floatLogicalBottom;
    202 
    203         if (newLineWidth >= m_uncommittedWidth)
    204             break;
    205     }
    206     updateLineDimension(lastFloatLogicalBottom, newLineWidth, newLineLeft, newLineRight);
    207 }
    208 
    209 void LineWidth::computeAvailableWidthFromLeftAndRight()
    210 {
    211     m_availableWidth = max(0.0f, m_right - m_left) + m_overhangWidth;
    212 }
    213 
    214 }
    215