/*

 * Copyright (C) 2009 Alex Milowski (alex@milowski.com). All rights reserved.

 * Copyright (C) 2010 François Sausset (sausset@gmail.com). All rights reserved.

 *

 * Redistribution and use in source and binary forms, with or without

 * modification, are permitted provided that the following conditions

 * are met:

 * 1. Redistributions of source code must retain the above copyright

 *    notice, this list of conditions and the following disclaimer.

 * 2. Redistributions in binary form must reproduce the above copyright

 *    notice, this list of conditions and the following disclaimer in the

 *    documentation and/or other materials provided with the distribution.

 *

 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS

 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT

 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR

 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT

 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,

 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT

 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,

 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY

 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT

 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE

 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

 */

#include "config.h"

#if ENABLE(MATHML)

#include "RenderMathMLFraction.h"

#include "GraphicsContext.h"

#include "MathMLNames.h"

#include "RenderText.h"

namespace WebCore {

using namespace MathMLNames;

static const double gHorizontalPad = 0.2;

static const int gLineThin = 1;

static const int gLineMedium = 3;

static const int gLineThick = 5;

static const double gFractionAlignment = 0.25;

static const double gFractionBarWidth = 0.05;

static const double gDenominatorPad = 0.1;

RenderMathMLFraction::RenderMathMLFraction(Element* fraction) 

    : RenderMathMLBlock(fraction)

    , m_lineThickness(gLineThin)

{

    setChildrenInline(false);

}

void RenderMathMLFraction::updateFromElement()

{

    // FIXME: mfrac where bevelled=true will need to reorganize the descendants

    if (isEmpty()) 

        return;

    Element* fraction = static_cast<Element*>(node());

    RenderObject* numerator = firstChild();

    String nalign = fraction->getAttribute(MathMLNames::numalignAttr);

    if (equalIgnoringCase(nalign, "left"))

        numerator->style()->setTextAlign(LEFT);

    else if (equalIgnoringCase(nalign, "right"))

        numerator->style()->setTextAlign(RIGHT);

    else

        numerator->style()->setTextAlign(CENTER);

    RenderObject* denominator = numerator->nextSibling();

    if (!denominator)

        return;

    String dalign = fraction->getAttribute(MathMLNames::denomalignAttr);

    if (equalIgnoringCase(dalign, "left"))

        denominator->style()->setTextAlign(LEFT);

    else if (equalIgnoringCase(dalign, "right"))

        denominator->style()->setTextAlign(RIGHT);

    else

        denominator->style()->setTextAlign(CENTER);

    // FIXME: parse units

    String thickness = fraction->getAttribute(MathMLNames::linethicknessAttr);

    m_lineThickness = gLineThin;

    if (equalIgnoringCase(thickness, "thin"))

        m_lineThickness = gLineThin;

    else if (equalIgnoringCase(thickness, "medium"))

        m_lineThickness = gLineMedium;

    else if (equalIgnoringCase(thickness, "thick"))

        m_lineThickness = gLineThick;

    else if (equalIgnoringCase(thickness, "0"))

        m_lineThickness = 0;

    // Update the style for the padding of the denominator for the line thickness

    lastChild()->style()->setPaddingTop(Length(static_cast<int>(m_lineThickness + style()->fontSize() * gDenominatorPad), Fixed));

}

void RenderMathMLFraction::addChild(RenderObject* child, RenderObject* beforeChild)

{

    RenderBlock* row = new (renderArena()) RenderMathMLBlock(node());

    RefPtr<RenderStyle> rowStyle = makeBlockStyle();

    rowStyle->setTextAlign(CENTER);

    Length pad(static_cast<int>(rowStyle->fontSize() * gHorizontalPad), Fixed);

    rowStyle->setPaddingLeft(pad);

    rowStyle->setPaddingRight(pad);

    // Only add padding for rows as denominators

    bool isNumerator = isEmpty();

    if (!isNumerator) 

        rowStyle->setPaddingTop(Length(2, Fixed));

    row->setStyle(rowStyle.release());

    RenderBlock::addChild(row, beforeChild);

    row->addChild(child);

    updateFromElement();

}

void RenderMathMLFraction::layout()

{

    updateFromElement();

    // Adjust the fraction line thickness for the zoom

    if (lastChild() && lastChild()->isRenderBlock())

        m_lineThickness = m_lineThickness * ceil(gFractionBarWidth * style()->fontSize());

    RenderBlock::layout();

    // The row layout can affect the numerator/denominator width.

    // FIXME: This is probably only needed if one of the children

    // contains an mrow.

    setNeedsLayoutAndPrefWidthsRecalc();

    markContainingBlocksForLayout();

    RenderBlock::layout();

}

void RenderMathMLFraction::paint(PaintInfo& info, int tx, int ty)

{

    RenderMathMLBlock::paint(info, tx, ty);

    if (info.context->paintingDisabled() || info.phase != PaintPhaseForeground)

        return;

    if (!firstChild() ||!m_lineThickness)

        return;

    int verticalOffset = 0;

    // The children are always RenderMathMLBlock instances

    if (firstChild()->isRenderMathMLBlock()) {

        int adjustForThickness = m_lineThickness > 1 ? m_lineThickness / 2 : 1;

        if (m_lineThickness % 2 == 1)

            adjustForThickness++;

        RenderMathMLBlock* numerator = toRenderMathMLBlock(firstChild());

        if (numerator->isRenderMathMLRow())

            verticalOffset = numerator->offsetHeight() + adjustForThickness;

        else 

            verticalOffset = numerator->offsetHeight();        

    }

    tx += x();

    ty += y() + verticalOffset;

    info.context->save();

    info.context->setStrokeThickness(static_cast<float>(m_lineThickness));

    info.context->setStrokeStyle(SolidStroke);

    info.context->setStrokeColor(style()->visitedDependentColor(CSSPropertyColor), sRGBColorSpace);

    info.context->drawLine(IntPoint(tx, ty), IntPoint(tx + offsetWidth(), ty));

    info.context->restore();

}

int RenderMathMLFraction::baselinePosition(bool firstLine, bool isRootLineBox) const

{

    if (firstChild()->isRenderMathMLBlock()) {

        RenderMathMLBlock* numerator = toRenderMathMLBlock(firstChild());

        // FIXME: the baseline should adjust so the fraction line aligns

        // relative certain operators (e.g. aligns with the horizontal

        // stroke of the plus).  1/3 of the current font size is just

        // a good guess.

        return numerator->offsetHeight() + style()->fontSize() / 3;

    }

    return RenderBlock::baselinePosition(firstLine, isRootLineBox);

}

}

#endif // ENABLE(MATHML)