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
37namespace WebCore {
38
39using namespace MathMLNames;
40
41static const float gLineThin = 0.33f;
42static const float gLineMedium = 1.f;
43static const float gLineThick = 3.f;
44static const float gFractionBarWidth = 0.05f;
45
46RenderMathMLFraction::RenderMathMLFraction(Element* element)
47    : RenderMathMLBlock(element)
48    , m_lineThickness(gLineMedium)
49{
50}
51
52void RenderMathMLFraction::fixChildStyle(RenderObject* child)
53{
54    ASSERT(child->isAnonymous() && child->style()->refCount() == 1);
55    child->style()->setFlexDirection(FlowColumn);
56}
57
58// FIXME: It's cleaner to only call updateFromElement when an attribute has changed. Move parts
59// of this to fixChildStyle or other methods, and call them when needed.
60void RenderMathMLFraction::updateFromElement()
61{
62    // FIXME: mfrac where bevelled=true will need to reorganize the descendants
63    if (isEmpty())
64        return;
65
66    Element* fraction = toElement(node());
67
68    RenderObject* numeratorWrapper = firstChild();
69    RenderObject* denominatorWrapper = numeratorWrapper->nextSibling();
70    if (!denominatorWrapper)
71        return;
72
73    String thickness = fraction->getAttribute(MathMLNames::linethicknessAttr);
74    m_lineThickness = gLineMedium;
75    if (equalIgnoringCase(thickness, "thin"))
76        m_lineThickness = gLineThin;
77    else if (equalIgnoringCase(thickness, "medium"))
78        m_lineThickness = gLineMedium;
79    else if (equalIgnoringCase(thickness, "thick"))
80        m_lineThickness = gLineThick;
81    else {
82        bool converted = false;
83        int thicknessIntValue = thickness.toIntStrict(&converted);
84        if (converted)
85            m_lineThickness = thicknessIntValue;
86    }
87
88    // Update the style for the padding of the denominator for the line thickness
89    lastChild()->style()->setPaddingTop(Length(static_cast<int>(m_lineThickness), Fixed));
90}
91
92void RenderMathMLFraction::addChild(RenderObject* child, RenderObject* /* beforeChild */)
93{
94    if (isEmpty()) {
95        RenderMathMLBlock* numeratorWrapper = createAnonymousMathMLBlock();
96        RenderMathMLBlock::addChild(numeratorWrapper);
97        fixChildStyle(numeratorWrapper);
98
99        RenderMathMLBlock* denominatorWrapper = createAnonymousMathMLBlock();
100        RenderMathMLBlock::addChild(denominatorWrapper);
101        fixChildStyle(denominatorWrapper);
102    }
103
104    if (firstChild()->isEmpty())
105        firstChild()->addChild(child);
106    else
107        lastChild()->addChild(child);
108
109    updateFromElement();
110}
111
112void RenderMathMLFraction::styleDidChange(StyleDifference diff, const RenderStyle* oldStyle)
113{
114    RenderMathMLBlock::styleDidChange(diff, oldStyle);
115
116    for (RenderObject* child = firstChild(); child; child = child->nextSibling())
117        fixChildStyle(child);
118    updateFromElement();
119}
120
121RenderMathMLOperator* RenderMathMLFraction::unembellishedOperator()
122{
123    RenderObject* numeratorWrapper = firstChild();
124    if (!numeratorWrapper)
125        return 0;
126    RenderObject* numerator = numeratorWrapper->firstChild();
127    if (!numerator || !numerator->isRenderMathMLBlock())
128        return 0;
129    return toRenderMathMLBlock(numerator)->unembellishedOperator();
130}
131
132void RenderMathMLFraction::layout()
133{
134    updateFromElement();
135
136    // Adjust the fraction line thickness for the zoom
137    if (lastChild() && lastChild()->isRenderBlock())
138        m_lineThickness *= ceilf(gFractionBarWidth * style()->fontSize());
139
140    RenderMathMLBlock::layout();
141}
142
143void RenderMathMLFraction::paint(PaintInfo& info, const LayoutPoint& paintOffset)
144{
145    RenderMathMLBlock::paint(info, paintOffset);
146    if (info.context->paintingDisabled() || info.phase != PaintPhaseForeground)
147        return;
148
149    RenderBox* denominatorWrapper = lastChildBox();
150    if (!denominatorWrapper || !m_lineThickness)
151        return;
152
153    IntPoint adjustedPaintOffset = roundedIntPoint(paintOffset + location() + denominatorWrapper->location() + LayoutPoint(0, m_lineThickness / 2));
154
155    GraphicsContextStateSaver stateSaver(*info.context);
156
157    info.context->setStrokeThickness(m_lineThickness);
158    info.context->setStrokeStyle(SolidStroke);
159    info.context->setStrokeColor(style()->visitedDependentColor(CSSPropertyColor), ColorSpaceSRGB);
160
161    info.context->drawLine(adjustedPaintOffset, IntPoint(adjustedPaintOffset.x() + denominatorWrapper->pixelSnappedOffsetWidth(), adjustedPaintOffset.y()));
162}
163
164int RenderMathMLFraction::firstLineBoxBaseline() const
165{
166    if (RenderBox* denominatorWrapper = lastChildBox())
167        return denominatorWrapper->logicalTop() + static_cast<int>(lroundf((m_lineThickness + style()->fontMetrics().xHeight()) / 2));
168    return RenderMathMLBlock::firstLineBoxBaseline();
169}
170
171}
172
173#endif // ENABLE(MATHML)
174