third_party/WebKit/Source/core/layout/line/LineWidth.cpp

   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/layout/line/LineWidth.h"
  32
  33 #include "core/layout/api/LineLayoutRubyRun.h"
  34 #include "core/layout/shapes/ShapeOutsideInfo.h"
  35
  36 namespace blink {
  37
  38 LineWidth::LineWidth(LineLayoutBlockFlow 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.minLineHeightForReplacedObject(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(const 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.layoutObject()->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(LineLayoutRubyRun rubyRun, LineLayoutItem startLayoutItem, LineLayoutItem endLayoutItem)
 109 {
 110     int startOverhang;
 111     int endOverhang;
 112     rubyRun.getOverhang(m_isFirstLine, startLayoutItem, endLayoutItem, 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(LineLayoutBlockFlow block, const LayoutUnit& offset, bool shouldIndentText, float& newLineLeft,
 123     float& newLineRight, const LayoutUnit& lineHeight = 0)
 124 {
 125     newLineLeft = block.logicalLeftOffsetForLine(offset, shouldIndentText, lineHeight).toFloat();
 126     newLineRight = block.logicalRightOffsetForLine(offset, shouldIndentText, lineHeight).toFloat();
 127     return std::max(0.0f, newLineRight - newLineLeft);
 128 }
 129
 130 void LineWidth::updateLineDimension(LayoutUnit newLineTop, LayoutUnit newLineWidth, const float& newLineLeft, const float& newLineRight)
 131 {
 132     if (newLineWidth <= m_availableWidth)
 133         return;
 134
 135     m_block.setLogicalHeight(newLineTop);
 136     m_availableWidth = newLineWidth + m_overhangWidth;
 137     m_left = newLineLeft;
 138     m_right = newLineRight;
 139 }
 140
 141 void LineWidth::wrapNextToShapeOutside(bool isFirstLine)
 142 {
 143     LayoutUnit lineHeight = m_block.lineHeight(isFirstLine, m_block.isHorizontalWritingMode() ? HorizontalLine : VerticalLine, PositionOfInteriorLineBoxes);
 144     LayoutUnit lineLogicalTop = m_block.logicalHeight();
 145     LayoutUnit newLineTop = lineLogicalTop;
 146     LayoutUnit floatLogicalBottom = m_block.nextFloatLogicalBottomBelow(lineLogicalTop);
 147
 148     float newLineWidth;
 149     float newLineLeft = m_left;
 150     float newLineRight = m_right;
 151     while (true) {
 152         newLineWidth = availableWidthAtOffset(m_block, newLineTop, shouldIndentText(), newLineLeft, newLineRight, lineHeight);
 153         if (newLineWidth >= m_uncommittedWidth)
 154             break;
 155
 156         if (newLineTop >= floatLogicalBottom)
 157             break;
 158
 159         newLineTop++;
 160     }
 161     updateLineDimension(newLineTop, newLineWidth, newLineLeft, newLineRight);
 162 }
 163
 164 void LineWidth::fitBelowFloats(bool isFirstLine)
 165 {
 166     ASSERT(!m_committedWidth);
 167     ASSERT(!fitsOnLine());
 168     m_block.positionNewFloats(this);
 169
 170     LayoutUnit floatLogicalBottom;
 171     LayoutUnit lastFloatLogicalBottom = m_block.logicalHeight();
 172     float newLineWidth = m_availableWidth;
 173     float newLineLeft = m_left;
 174     float newLineRight = m_right;
 175
 176     FloatingObject* lastFloatFromPreviousLine = m_block.lastFloatFromPreviousLine();
 177         if (lastFloatFromPreviousLine && lastFloatFromPreviousLine->layoutObject()->shapeOutsideInfo())
 178             return wrapNextToShapeOutside(isFirstLine);
 179
 180     while (true) {
 181         floatLogicalBottom = m_block.nextFloatLogicalBottomBelow(lastFloatLogicalBottom, ShapeOutsideFloatShapeOffset);
 182         if (floatLogicalBottom <= lastFloatLogicalBottom)
 183             break;
 184
 185         newLineWidth = availableWidthAtOffset(m_block, floatLogicalBottom, shouldIndentText(), newLineLeft, newLineRight);
 186         lastFloatLogicalBottom = floatLogicalBottom;
 187
 188         if (newLineWidth >= m_uncommittedWidth)
 189             break;
 190     }
 191     updateLineDimension(lastFloatLogicalBottom, newLineWidth, newLineLeft, newLineRight);
 192 }
 193
 194 void LineWidth::computeAvailableWidthFromLeftAndRight()
 195 {
 196     m_availableWidth = max(0.0f, m_right - m_left) + m_overhangWidth;
 197 }
 198
 199 }