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      1 /*
      2  * Copyright (C) 1999 Lars Knoll (knoll (at) kde.org)
      3  *           (C) 1999 Antti Koivisto (koivisto (at) kde.org)
      4  *           (C) 2000 Dirk Mueller (mueller (at) 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/rendering/RenderFieldset.h"
     26 
     27 #include "core/CSSPropertyNames.h"
     28 #include "core/HTMLNames.h"
     29 #include "core/html/HTMLLegendElement.h"
     30 #include "core/paint/BoxDecorationData.h"
     31 #include "core/paint/BoxPainter.h"
     32 #include "core/rendering/PaintInfo.h"
     33 #include "platform/graphics/GraphicsContextStateSaver.h"
     34 
     35 using std::min;
     36 using std::max;
     37 
     38 namespace blink {
     39 
     40 using namespace HTMLNames;
     41 
     42 RenderFieldset::RenderFieldset(Element* element)
     43     : RenderBlockFlow(element)
     44 {
     45 }
     46 
     47 void RenderFieldset::computePreferredLogicalWidths()
     48 {
     49     RenderBlockFlow::computePreferredLogicalWidths();
     50     if (RenderBox* legend = findLegend()) {
     51         int legendMinWidth = legend->minPreferredLogicalWidth();
     52 
     53         Length legendMarginLeft = legend->style()->marginLeft();
     54         Length legendMarginRight = legend->style()->marginLeft();
     55 
     56         if (legendMarginLeft.isFixed())
     57             legendMinWidth += legendMarginLeft.value();
     58 
     59         if (legendMarginRight.isFixed())
     60             legendMinWidth += legendMarginRight.value();
     61 
     62         m_minPreferredLogicalWidth = max(m_minPreferredLogicalWidth, legendMinWidth + borderAndPaddingWidth());
     63     }
     64 }
     65 
     66 RenderObject* RenderFieldset::layoutSpecialExcludedChild(bool relayoutChildren, SubtreeLayoutScope&)
     67 {
     68     RenderBox* legend = findLegend();
     69     if (legend) {
     70         if (relayoutChildren)
     71             legend->setNeedsLayoutAndFullPaintInvalidation();
     72         legend->layoutIfNeeded();
     73 
     74         LayoutUnit logicalLeft;
     75         if (style()->isLeftToRightDirection()) {
     76             switch (legend->style()->textAlign()) {
     77             case CENTER:
     78                 logicalLeft = (logicalWidth() - logicalWidthForChild(legend)) / 2;
     79                 break;
     80             case RIGHT:
     81                 logicalLeft = logicalWidth() - borderEnd() - paddingEnd() - logicalWidthForChild(legend);
     82                 break;
     83             default:
     84                 logicalLeft = borderStart() + paddingStart() + marginStartForChild(legend);
     85                 break;
     86             }
     87         } else {
     88             switch (legend->style()->textAlign()) {
     89             case LEFT:
     90                 logicalLeft = borderStart() + paddingStart();
     91                 break;
     92             case CENTER: {
     93                 // Make sure that the extra pixel goes to the end side in RTL (since it went to the end side
     94                 // in LTR).
     95                 LayoutUnit centeredWidth = logicalWidth() - logicalWidthForChild(legend);
     96                 logicalLeft = centeredWidth - centeredWidth / 2;
     97                 break;
     98             }
     99             default:
    100                 logicalLeft = logicalWidth() - borderStart() - paddingStart() - marginStartForChild(legend) - logicalWidthForChild(legend);
    101                 break;
    102             }
    103         }
    104 
    105         setLogicalLeftForChild(legend, logicalLeft);
    106 
    107         LayoutUnit fieldsetBorderBefore = borderBefore();
    108         LayoutUnit legendLogicalHeight = logicalHeightForChild(legend);
    109 
    110         LayoutUnit legendLogicalTop;
    111         LayoutUnit collapsedLegendExtent;
    112         // FIXME: We need to account for the legend's margin before too.
    113         if (fieldsetBorderBefore > legendLogicalHeight) {
    114             // The <legend> is smaller than the associated fieldset before border
    115             // so the latter determines positioning of the <legend>. The sizing depends
    116             // on the legend's margins as we want to still follow the author's cues.
    117             // Firefox completely ignores the margins in this case which seems wrong.
    118             legendLogicalTop = (fieldsetBorderBefore - legendLogicalHeight) / 2;
    119             collapsedLegendExtent = max<LayoutUnit>(fieldsetBorderBefore, legendLogicalTop + legendLogicalHeight + marginAfterForChild(legend));
    120         } else
    121             collapsedLegendExtent = legendLogicalHeight + marginAfterForChild(legend);
    122 
    123         setLogicalTopForChild(legend, legendLogicalTop);
    124         setLogicalHeight(paddingBefore() + collapsedLegendExtent);
    125     }
    126     return legend;
    127 }
    128 
    129 RenderBox* RenderFieldset::findLegend(FindLegendOption option) const
    130 {
    131     for (RenderObject* legend = firstChild(); legend; legend = legend->nextSibling()) {
    132         if (option == IgnoreFloatingOrOutOfFlow && legend->isFloatingOrOutOfFlowPositioned())
    133             continue;
    134 
    135         if (isHTMLLegendElement(legend->node()))
    136             return toRenderBox(legend);
    137     }
    138     return 0;
    139 }
    140 
    141 void RenderFieldset::paintBoxDecorationBackground(PaintInfo& paintInfo, const LayoutPoint& paintOffset)
    142 {
    143     if (!paintInfo.shouldPaintWithinRoot(this))
    144         return;
    145 
    146     LayoutRect paintRect(paintOffset, size());
    147     RenderBox* legend = findLegend();
    148     if (!legend)
    149         return RenderBlockFlow::paintBoxDecorationBackground(paintInfo, paintOffset);
    150 
    151     // FIXME: We need to work with "rl" and "bt" block flow directions.  In those
    152     // cases the legend is embedded in the right and bottom borders respectively.
    153     // https://bugs.webkit.org/show_bug.cgi?id=47236
    154     if (style()->isHorizontalWritingMode()) {
    155         LayoutUnit yOff = (legend->y() > 0) ? LayoutUnit() : (legend->height() - borderTop()) / 2;
    156         paintRect.setHeight(paintRect.height() - yOff);
    157         paintRect.setY(paintRect.y() + yOff);
    158     } else {
    159         LayoutUnit xOff = (legend->x() > 0) ? LayoutUnit() : (legend->width() - borderLeft()) / 2;
    160         paintRect.setWidth(paintRect.width() - xOff);
    161         paintRect.setX(paintRect.x() + xOff);
    162     }
    163 
    164     BoxDecorationData boxDecorationData(*style(), canRenderBorderImage(), backgroundHasOpaqueTopLayer(), paintInfo.context);
    165 
    166     if (boxDecorationData.bleedAvoidance() == BackgroundBleedNone)
    167         BoxPainter::paintBoxShadow(paintInfo, paintRect, style(), Normal);
    168     BoxPainter(*this).paintFillLayers(paintInfo, boxDecorationData.backgroundColor, style()->backgroundLayers(), paintRect);
    169     BoxPainter::paintBoxShadow(paintInfo, paintRect, style(), Inset);
    170 
    171     if (!boxDecorationData.hasBorder)
    172         return;
    173 
    174     // Create a clipping region around the legend and paint the border as normal
    175     GraphicsContext* graphicsContext = paintInfo.context;
    176     GraphicsContextStateSaver stateSaver(*graphicsContext);
    177 
    178     // FIXME: We need to work with "rl" and "bt" block flow directions.  In those
    179     // cases the legend is embedded in the right and bottom borders respectively.
    180     // https://bugs.webkit.org/show_bug.cgi?id=47236
    181     if (style()->isHorizontalWritingMode()) {
    182         LayoutUnit clipTop = paintRect.y();
    183         LayoutUnit clipHeight = max(static_cast<LayoutUnit>(style()->borderTopWidth()), legend->height() - ((legend->height() - borderTop()) / 2));
    184         graphicsContext->clipOut(pixelSnappedIntRect(paintRect.x() + legend->x(), clipTop, legend->width(), clipHeight));
    185     } else {
    186         LayoutUnit clipLeft = paintRect.x();
    187         LayoutUnit clipWidth = max(static_cast<LayoutUnit>(style()->borderLeftWidth()), legend->width());
    188         graphicsContext->clipOut(pixelSnappedIntRect(clipLeft, paintRect.y() + legend->y(), clipWidth, legend->height()));
    189     }
    190 
    191     BoxPainter::paintBorder(*this, paintInfo, paintRect, style());
    192 }
    193 
    194 void RenderFieldset::paintMask(PaintInfo& paintInfo, const LayoutPoint& paintOffset)
    195 {
    196     if (style()->visibility() != VISIBLE || paintInfo.phase != PaintPhaseMask)
    197         return;
    198 
    199     LayoutRect paintRect = LayoutRect(paintOffset, size());
    200     RenderBox* legend = findLegend();
    201     if (!legend)
    202         return RenderBlockFlow::paintMask(paintInfo, paintOffset);
    203 
    204     // FIXME: We need to work with "rl" and "bt" block flow directions.  In those
    205     // cases the legend is embedded in the right and bottom borders respectively.
    206     // https://bugs.webkit.org/show_bug.cgi?id=47236
    207     if (style()->isHorizontalWritingMode()) {
    208         LayoutUnit yOff = (legend->y() > 0) ? LayoutUnit() : (legend->height() - borderTop()) / 2;
    209         paintRect.expand(0, -yOff);
    210         paintRect.move(0, yOff);
    211     } else {
    212         LayoutUnit xOff = (legend->x() > 0) ? LayoutUnit() : (legend->width() - borderLeft()) / 2;
    213         paintRect.expand(-xOff, 0);
    214         paintRect.move(xOff, 0);
    215     }
    216 
    217     BoxPainter(*this).paintMaskImages(paintInfo, paintRect);
    218 }
    219 
    220 } // namespace blink
    221