third_party/WebKit/Source/core/paint/MultiColumnSetPainter.cpp

   1 // Copyright 2014 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include "config.h"
   6 #include "core/paint/MultiColumnSetPainter.h"
   7
   8 #include "core/layout/LayoutMultiColumnSet.h"
   9 #include "core/paint/BlockPainter.h"
  10 #include "core/paint/BoxPainter.h"
  11 #include "core/paint/LayoutObjectDrawingRecorder.h"
  12 #include "core/paint/PaintInfo.h"
  13 #include "platform/geometry/LayoutPoint.h"
  14
  15 namespace blink {
  16
  17 void MultiColumnSetPainter::paintObject(const PaintInfo& paintInfo, const LayoutPoint& paintOffset)
  18 {
  19     if (m_layoutMultiColumnSet.style()->visibility() != VISIBLE)
  20         return;
  21
  22     BlockPainter(m_layoutMultiColumnSet).paintObject(paintInfo, paintOffset);
  23
  24     // FIXME: Right now we're only painting in the foreground phase.
  25     // Columns should technically respect phases and allow for background/float/foreground overlap etc., just like
  26     // LayoutBlocks do. Note this is a pretty minor issue, since the old column implementation clipped columns
  27     // anyway, thus making it impossible for them to overlap one another. It's also really unlikely that the columns
  28     // would overlap another block.
  29     if (!m_layoutMultiColumnSet.flowThread() || (paintInfo.phase != PaintPhaseForeground && paintInfo.phase != PaintPhaseSelection))
  30         return;
  31
  32     paintColumnRules(paintInfo, paintOffset);
  33 }
  34
  35 void MultiColumnSetPainter::paintColumnRules(const PaintInfo& paintInfo, const LayoutPoint& paintOffset)
  36 {
  37     if (m_layoutMultiColumnSet.flowThread()->isLayoutPagedFlowThread())
  38         return;
  39
  40     const ComputedStyle& blockStyle = m_layoutMultiColumnSet.multiColumnBlockFlow()->styleRef();
  41     const Color& ruleColor = m_layoutMultiColumnSet.resolveColor(blockStyle, CSSPropertyWebkitColumnRuleColor);
  42     bool ruleTransparent = blockStyle.columnRuleIsTransparent();
  43     EBorderStyle ruleStyle = blockStyle.columnRuleStyle();
  44     LayoutUnit ruleThickness = blockStyle.columnRuleWidth();
  45     LayoutUnit colGap = m_layoutMultiColumnSet.columnGap();
  46     bool renderRule = ruleStyle > BHIDDEN && !ruleTransparent;
  47     if (!renderRule)
  48         return;
  49
  50     unsigned colCount = m_layoutMultiColumnSet.actualColumnCount();
  51     if (colCount <= 1)
  52         return;
  53
  54     if (LayoutObjectDrawingRecorder::useCachedDrawingIfPossible(*paintInfo.context, m_layoutMultiColumnSet, DisplayItem::ColumnRules, paintOffset))
  55         return;
  56
  57     LayoutRect paintRect = m_layoutMultiColumnSet.visualOverflowRect();
  58     paintRect.moveBy(paintOffset);
  59     LayoutObjectDrawingRecorder drawingRecorder(*paintInfo.context, m_layoutMultiColumnSet, DisplayItem::ColumnRules, paintRect, paintOffset);
  60
  61     bool leftToRight = m_layoutMultiColumnSet.style()->isLeftToRightDirection();
  62     LayoutUnit currLogicalLeftOffset = leftToRight ? LayoutUnit() : m_layoutMultiColumnSet.contentLogicalWidth();
  63     LayoutUnit ruleAdd = m_layoutMultiColumnSet.borderAndPaddingLogicalLeft();
  64     LayoutUnit ruleLogicalLeft = leftToRight ? LayoutUnit() : m_layoutMultiColumnSet.contentLogicalWidth();
  65     LayoutUnit inlineDirectionSize = m_layoutMultiColumnSet.pageLogicalWidth();
  66     BoxSide boxSide = m_layoutMultiColumnSet.isHorizontalWritingMode()
  67         ? leftToRight ? BSLeft : BSRight
  68         : leftToRight ? BSTop : BSBottom;
  69
  70     for (unsigned i = 0; i < colCount; i++) {
  71         // Move to the next position.
  72         if (leftToRight) {
  73             ruleLogicalLeft += inlineDirectionSize + colGap / 2;
  74             currLogicalLeftOffset += inlineDirectionSize + colGap;
  75         } else {
  76             ruleLogicalLeft -= (inlineDirectionSize + colGap / 2);
  77             currLogicalLeftOffset -= (inlineDirectionSize + colGap);
  78         }
  79
  80         // Now paint the column rule.
  81         if (i < colCount - 1) {
  82             LayoutUnit ruleLeft = m_layoutMultiColumnSet.isHorizontalWritingMode() ? paintOffset.x() + ruleLogicalLeft - ruleThickness / 2 + ruleAdd : paintOffset.x() + m_layoutMultiColumnSet.borderLeft() + m_layoutMultiColumnSet.paddingLeft();
  83             LayoutUnit ruleRight = m_layoutMultiColumnSet.isHorizontalWritingMode() ? ruleLeft + ruleThickness : ruleLeft + m_layoutMultiColumnSet.contentWidth();
  84             LayoutUnit ruleTop = m_layoutMultiColumnSet.isHorizontalWritingMode() ? paintOffset.y() + m_layoutMultiColumnSet.borderTop() + m_layoutMultiColumnSet.paddingTop() : paintOffset.y() + ruleLogicalLeft - ruleThickness / 2 + ruleAdd;
  85             LayoutUnit ruleBottom = m_layoutMultiColumnSet.isHorizontalWritingMode() ? ruleTop + m_layoutMultiColumnSet.contentHeight() : ruleTop + ruleThickness;
  86             IntRect pixelSnappedRuleRect = pixelSnappedIntRectFromEdges(ruleLeft, ruleTop, ruleRight, ruleBottom);
  87             ObjectPainter::drawLineForBoxSide(paintInfo.context, pixelSnappedRuleRect.x(), pixelSnappedRuleRect.y(), pixelSnappedRuleRect.maxX(), pixelSnappedRuleRect.maxY(), boxSide, ruleColor, ruleStyle, 0, 0, true);
  88         }
  89
  90         ruleLogicalLeft = currLogicalLeftOffset;
  91     }
  92 }
  93
  94 } // namespace blink