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/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
35using std::min;
36using std::max;
37
38namespace blink {
39
40using namespace HTMLNames;
41
42RenderFieldset::RenderFieldset(Element* element)
43    : RenderBlockFlow(element)
44{
45}
46
47void 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
66RenderObject* 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
129RenderBox* 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
141void 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
194void 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