third_party/WebKit/Source/core/layout/LayoutFieldset.cpp

   1 /*
   2  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
   3  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
   4  *           (C) 2000 Dirk Mueller (mueller@kde.org)
   5  * Copyright (C) 2004, 2005, 2006 Apple Computer, Inc.
   6  *
   7  * This library is free software; you can redistribute it and/or
   8  * modify it under the terms of the GNU Library General Public
   9  * License as published by the Free Software Foundation; either
  10  * version 2 of the License, or (at your option) any later version.
  11  *
  12  * This library is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  15  * Library General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU Library General Public License
  18  * along with this library; see the file COPYING.LIB.  If not, write to
  19  * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
  20  * Boston, MA 02110-1301, USA.
  21  *
  22  */
  23
  24 #include "config.h"
  25 #include "core/layout/LayoutFieldset.h"
  26
  27 #include "core/CSSPropertyNames.h"
  28 #include "core/HTMLNames.h"
  29 #include "core/html/HTMLLegendElement.h"
  30 #include "core/paint/FieldsetPainter.h"
  31
  32 using namespace std;
  33
  34 namespace blink {
  35
  36 using namespace HTMLNames;
  37
  38 LayoutFieldset::LayoutFieldset(Element* element)
  39     : LayoutBlockFlow(element)
  40 {
  41 }
  42
  43 void LayoutFieldset::computePreferredLogicalWidths()
  44 {
  45     LayoutBlockFlow::computePreferredLogicalWidths();
  46     if (LayoutBox* legend = findInFlowLegend()) {
  47         int legendMinWidth = legend->minPreferredLogicalWidth();
  48
  49         Length legendMarginLeft = legend->style()->marginLeft();
  50         Length legendMarginRight = legend->style()->marginLeft();
  51
  52         if (legendMarginLeft.isFixed())
  53             legendMinWidth += legendMarginLeft.value();
  54
  55         if (legendMarginRight.isFixed())
  56             legendMinWidth += legendMarginRight.value();
  57
  58         m_minPreferredLogicalWidth = max(m_minPreferredLogicalWidth, legendMinWidth + borderAndPaddingWidth());
  59     }
  60 }
  61
  62 LayoutObject* LayoutFieldset::layoutSpecialExcludedChild(bool relayoutChildren, SubtreeLayoutScope&)
  63 {
  64     LayoutBox* legend = findInFlowLegend();
  65     if (legend) {
  66         LayoutRect oldLegendFrameRect = legend->frameRect();
  67
  68         if (relayoutChildren)
  69             legend->setNeedsLayoutAndFullPaintInvalidation(LayoutInvalidationReason::FieldsetChanged);
  70         legend->layoutIfNeeded();
  71
  72         LayoutUnit logicalLeft;
  73         if (style()->isLeftToRightDirection()) {
  74             switch (legend->style()->textAlign()) {
  75             case CENTER:
  76                 logicalLeft = (logicalWidth() - logicalWidthForChild(*legend)) / 2;
  77                 break;
  78             case RIGHT:
  79                 logicalLeft = logicalWidth() - borderEnd() - paddingEnd() - logicalWidthForChild(*legend);
  80                 break;
  81             default:
  82                 logicalLeft = borderStart() + paddingStart() + marginStartForChild(*legend);
  83                 break;
  84             }
  85         } else {
  86             switch (legend->style()->textAlign()) {
  87             case LEFT:
  88                 logicalLeft = borderStart() + paddingStart();
  89                 break;
  90             case CENTER: {
  91                 // Make sure that the extra pixel goes to the end side in RTL (since it went to the end side
  92                 // in LTR).
  93                 LayoutUnit centeredWidth = logicalWidth() - logicalWidthForChild(*legend);
  94                 logicalLeft = centeredWidth - centeredWidth / 2;
  95                 break;
  96             }
  97             default:
  98                 logicalLeft = logicalWidth() - borderStart() - paddingStart() - marginStartForChild(*legend) - logicalWidthForChild(*legend);
  99                 break;
 100             }
 101         }
 102
 103         setLogicalLeftForChild(*legend, logicalLeft);
 104
 105         LayoutUnit fieldsetBorderBefore = borderBefore();
 106         LayoutUnit legendLogicalHeight = logicalHeightForChild(*legend);
 107
 108         LayoutUnit legendLogicalTop;
 109         LayoutUnit collapsedLegendExtent;
 110         // FIXME: We need to account for the legend's margin before too.
 111         if (fieldsetBorderBefore > legendLogicalHeight) {
 112             // The <legend> is smaller than the associated fieldset before border
 113             // so the latter determines positioning of the <legend>. The sizing depends
 114             // on the legend's margins as we want to still follow the author's cues.
 115             // Firefox completely ignores the margins in this case which seems wrong.
 116             legendLogicalTop = (fieldsetBorderBefore - legendLogicalHeight) / 2;
 117             collapsedLegendExtent = max<LayoutUnit>(fieldsetBorderBefore, legendLogicalTop + legendLogicalHeight + marginAfterForChild(*legend));
 118         } else {
 119             collapsedLegendExtent = legendLogicalHeight + marginAfterForChild(*legend);
 120         }
 121
 122         setLogicalTopForChild(*legend, legendLogicalTop);
 123         setLogicalHeight(paddingBefore() + collapsedLegendExtent);
 124
 125         if (legend->frameRect() != oldLegendFrameRect) {
 126             // We need to invalidate the fieldset border if the legend's frame changed.
 127             setShouldDoFullPaintInvalidation();
 128         }
 129     }
 130     return legend;
 131 }
 132
 133 LayoutBox* LayoutFieldset::findInFlowLegend() const
 134 {
 135     for (LayoutObject* legend = firstChild(); legend; legend = legend->nextSibling()) {
 136         if (legend->isFloatingOrOutOfFlowPositioned())
 137             continue;
 138
 139         if (isHTMLLegendElement(legend->node()))
 140             return toLayoutBox(legend);
 141     }
 142     return nullptr;
 143 }
 144
 145 void LayoutFieldset::paintBoxDecorationBackground(const PaintInfo& paintInfo, const LayoutPoint& paintOffset)
 146 {
 147     FieldsetPainter(*this).paintBoxDecorationBackground(paintInfo, paintOffset);
 148 }
 149
 150 void LayoutFieldset::paintMask(const PaintInfo& paintInfo, const LayoutPoint& paintOffset)
 151 {
 152     FieldsetPainter(*this).paintMask(paintInfo, paintOffset);
 153 }
 154
 155 } // namespace blink