1/*
2 * Copyright (C) 2009 Alex Milowski (alex@milowski.com). All rights reserved.
3 * Copyright (C) 2010 François Sausset (sausset@gmail.com). All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 *    notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 *    notice, this list of conditions and the following disclaimer in the
12 *    documentation and/or other materials provided with the distribution.
13 *
14 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
15 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
16 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
17 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
18 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
19 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
20 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
21 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
22 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
23 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
24 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
25 */
26
27#include "config.h"
28
29#if ENABLE(MATHML)
30
31#include "RenderMathMLFraction.h"
32
33#include "GraphicsContext.h"
34#include "MathMLNames.h"
35#include "PaintInfo.h"
36#include "RenderText.h"
37
38namespace WebCore {
39
40using namespace MathMLNames;
41
42static const float gHorizontalPad = 0.2f;
43static const float gLineThin = 0.33f;
44static const float gLineMedium = 1.f;
45static const float gLineThick = 3.f;
46static const float gFractionBarWidth = 0.05f;
47static const float gDenominatorPad = 0.1f;
48
49RenderMathMLFraction::RenderMathMLFraction(Element* fraction)
50    : RenderMathMLBlock(fraction)
51    , m_lineThickness(gLineMedium)
52{
53    setChildrenInline(false);
54}
55
56void RenderMathMLFraction::updateFromElement()
57{
58    // FIXME: mfrac where bevelled=true will need to reorganize the descendants
59    if (isEmpty())
60        return;
61
62    Element* fraction = static_cast<Element*>(node());
63
64    RenderObject* numerator = firstChild();
65    String nalign = fraction->getAttribute(MathMLNames::numalignAttr);
66    if (equalIgnoringCase(nalign, "left"))
67        numerator->style()->setTextAlign(LEFT);
68    else if (equalIgnoringCase(nalign, "right"))
69        numerator->style()->setTextAlign(RIGHT);
70    else
71        numerator->style()->setTextAlign(CENTER);
72
73    RenderObject* denominator = numerator->nextSibling();
74    if (!denominator)
75        return;
76
77    String dalign = fraction->getAttribute(MathMLNames::denomalignAttr);
78    if (equalIgnoringCase(dalign, "left"))
79        denominator->style()->setTextAlign(LEFT);
80    else if (equalIgnoringCase(dalign, "right"))
81        denominator->style()->setTextAlign(RIGHT);
82    else
83        denominator->style()->setTextAlign(CENTER);
84
85    // FIXME: parse units
86    String thickness = fraction->getAttribute(MathMLNames::linethicknessAttr);
87    m_lineThickness = gLineMedium;
88    if (equalIgnoringCase(thickness, "thin"))
89        m_lineThickness = gLineThin;
90    else if (equalIgnoringCase(thickness, "medium"))
91        m_lineThickness = gLineMedium;
92    else if (equalIgnoringCase(thickness, "thick"))
93        m_lineThickness = gLineThick;
94    else if (equalIgnoringCase(thickness, "0"))
95        m_lineThickness = 0;
96
97    // Update the style for the padding of the denominator for the line thickness
98    lastChild()->style()->setPaddingTop(Length(static_cast<int>(m_lineThickness + style()->fontSize() * gDenominatorPad), Fixed));
99}
100
101void RenderMathMLFraction::addChild(RenderObject* child, RenderObject* beforeChild)
102{
103    RenderBlock* row = new (renderArena()) RenderMathMLBlock(node());
104    RefPtr<RenderStyle> rowStyle = makeBlockStyle();
105
106    rowStyle->setTextAlign(CENTER);
107    Length pad(static_cast<int>(rowStyle->fontSize() * gHorizontalPad), Fixed);
108    rowStyle->setPaddingLeft(pad);
109    rowStyle->setPaddingRight(pad);
110
111    // Only add padding for rows as denominators
112    bool isNumerator = isEmpty();
113    if (!isNumerator)
114        rowStyle->setPaddingTop(Length(2, Fixed));
115
116    row->setStyle(rowStyle.release());
117    RenderBlock::addChild(row, beforeChild);
118    row->addChild(child);
119    updateFromElement();
120}
121
122void RenderMathMLFraction::layout()
123{
124    updateFromElement();
125
126    // Adjust the fraction line thickness for the zoom
127    if (lastChild() && lastChild()->isRenderBlock())
128        m_lineThickness *= ceilf(gFractionBarWidth * style()->fontSize());
129
130    RenderBlock::layout();
131
132}
133
134void RenderMathMLFraction::paint(PaintInfo& info, int tx, int ty)
135{
136    RenderMathMLBlock::paint(info, tx, ty);
137    if (info.context->paintingDisabled() || info.phase != PaintPhaseForeground)
138        return;
139
140    if (!firstChild() ||!m_lineThickness)
141        return;
142
143    int verticalOffset = 0;
144    // The children are always RenderMathMLBlock instances
145    if (firstChild()->isRenderMathMLBlock()) {
146        int adjustForThickness = m_lineThickness > 1 ? int(m_lineThickness / 2) : 1;
147        if (int(m_lineThickness) % 2 == 1)
148            adjustForThickness++;
149        RenderMathMLBlock* numerator = toRenderMathMLBlock(firstChild());
150        if (numerator->isRenderMathMLRow())
151            verticalOffset = numerator->offsetHeight() + adjustForThickness;
152        else
153            verticalOffset = numerator->offsetHeight();
154    }
155
156    tx += x();
157    ty += y() + verticalOffset;
158
159    info.context->save();
160
161    info.context->setStrokeThickness(m_lineThickness);
162    info.context->setStrokeStyle(SolidStroke);
163    info.context->setStrokeColor(style()->visitedDependentColor(CSSPropertyColor), ColorSpaceSRGB);
164
165    info.context->drawLine(IntPoint(tx, ty), IntPoint(tx + offsetWidth(), ty));
166
167    info.context->restore();
168}
169
170int RenderMathMLFraction::baselinePosition(FontBaseline, bool firstLine, LineDirectionMode lineDirection, LinePositionMode linePositionMode) const
171{
172    if (firstChild() && firstChild()->isRenderMathMLBlock()) {
173        RenderMathMLBlock* numerator = toRenderMathMLBlock(firstChild());
174        RenderStyle* refStyle = style();
175        if (previousSibling())
176            refStyle = previousSibling()->style();
177        else if (nextSibling())
178            refStyle = nextSibling()->style();
179        int shift = int(ceil((refStyle->fontMetrics().xHeight() + 1) / 2));
180        return numerator->offsetHeight() + shift;
181    }
182    return RenderBlock::baselinePosition(AlphabeticBaseline, firstLine, lineDirection, linePositionMode);
183}
184
185}
186
187
188#endif // ENABLE(MATHML)
189