root/Source/core/html/HTMLMeterElement.cpp

DEFINITIONS

1. create
2. createRenderer
3. parseAttribute
4. min
5. setMin
6. max
7. setMax
8. value
9. setValue
10. low
11. setLow
12. high
13. setHigh
14. optimum
15. setOptimum
16. gaugeRegion
17. valueRatio
18. didElementStateChange
19. renderMeter
20. didAddUserAgentShadowRoot

/*
 * Copyright (C) 2010 Nokia Corporation and/or its subsidiary(-ies).
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Library General Public
 * License as published by the Free Software Foundation; either
 * version 2 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Library General Public License for more details.
 *
 * You should have received a copy of the GNU Library General Public License
 * along with this library; see the file COPYING.LIB.  If not, write to
 * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
 * Boston, MA 02110-1301, USA.
 *
 */

#include "config.h"

#include "core/html/HTMLMeterElement.h"

#include "HTMLNames.h"
#include "bindings/v8/ExceptionMessages.h"
#include "bindings/v8/ExceptionState.h"
#include "bindings/v8/ExceptionStatePlaceholder.h"
#include "core/dom/ExceptionCode.h"
#include "core/dom/shadow/ShadowRoot.h"
#include "core/html/parser/HTMLParserIdioms.h"
#include "core/html/shadow/MeterShadowElement.h"
#include "core/rendering/RenderMeter.h"
#include "core/rendering/RenderTheme.h"

namespace WebCore {

using namespace HTMLNames;

HTMLMeterElement::HTMLMeterElement(Document& document)
    : LabelableElement(meterTag, document)
{
    ScriptWrappable::init(this);
}

HTMLMeterElement::~HTMLMeterElement()
{
}

PassRefPtr<HTMLMeterElement> HTMLMeterElement::create(Document& document)
{
    RefPtr<HTMLMeterElement> meter = adoptRef(new HTMLMeterElement(document));
    meter->ensureUserAgentShadowRoot();
    return meter;
}

RenderObject* HTMLMeterElement::createRenderer(RenderStyle* style)
{
    if (hasAuthorShadowRoot() || !RenderTheme::theme().supportsMeter(style->appearance()))
        return RenderObject::createObject(this, style);

    return new RenderMeter(this);
}

void HTMLMeterElement::parseAttribute(const QualifiedName& name, const AtomicString& value)
{
    if (name == valueAttr || name == minAttr || name == maxAttr || name == lowAttr || name == highAttr || name == optimumAttr)
        didElementStateChange();
    else
        LabelableElement::parseAttribute(name, value);
}

double HTMLMeterElement::min() const
{
    return getFloatingPointAttribute(minAttr, 0);
}

void HTMLMeterElement::setMin(double min, ExceptionState& exceptionState)
{
    if (!std::isfinite(min)) {
        exceptionState.throwTypeError(ExceptionMessages::notAFiniteNumber(min));
        return;
    }
    setFloatingPointAttribute(minAttr, min);
}

double HTMLMeterElement::max() const
{
    return std::max(getFloatingPointAttribute(maxAttr, std::max(1.0, min())), min());
}

void HTMLMeterElement::setMax(double max, ExceptionState& exceptionState)
{
    if (!std::isfinite(max)) {
        exceptionState.throwTypeError(ExceptionMessages::notAFiniteNumber(max));
        return;
    }
    setFloatingPointAttribute(maxAttr, max);
}

double HTMLMeterElement::value() const
{
    double value = getFloatingPointAttribute(valueAttr, 0);
    return std::min(std::max(value, min()), max());
}

void HTMLMeterElement::setValue(double value, ExceptionState& exceptionState)
{
    if (!std::isfinite(value)) {
        exceptionState.throwTypeError(ExceptionMessages::notAFiniteNumber(value));
        return;
    }
    setFloatingPointAttribute(valueAttr, value);
}

double HTMLMeterElement::low() const
{
    double low = getFloatingPointAttribute(lowAttr, min());
    return std::min(std::max(low, min()), max());
}

void HTMLMeterElement::setLow(double low, ExceptionState& exceptionState)
{
    if (!std::isfinite(low)) {
        exceptionState.throwTypeError(ExceptionMessages::notAFiniteNumber(low));
        return;
    }
    setFloatingPointAttribute(lowAttr, low);
}

double HTMLMeterElement::high() const
{
    double high = getFloatingPointAttribute(highAttr, max());
    return std::min(std::max(high, low()), max());
}

void HTMLMeterElement::setHigh(double high, ExceptionState& exceptionState)
{
    if (!std::isfinite(high)) {
        exceptionState.throwTypeError(ExceptionMessages::notAFiniteNumber(high));
        return;
    }
    setFloatingPointAttribute(highAttr, high);
}

double HTMLMeterElement::optimum() const
{
    double optimum = getFloatingPointAttribute(optimumAttr, (max() + min()) / 2);
    return std::min(std::max(optimum, min()), max());
}

void HTMLMeterElement::setOptimum(double optimum, ExceptionState& exceptionState)
{
    if (!std::isfinite(optimum)) {
        exceptionState.throwTypeError(ExceptionMessages::notAFiniteNumber(optimum));
        return;
    }
    setFloatingPointAttribute(optimumAttr, optimum);
}

HTMLMeterElement::GaugeRegion HTMLMeterElement::gaugeRegion() const
{
    double lowValue = low();
    double highValue = high();
    double theValue = value();
    double optimumValue = optimum();

    if (optimumValue < lowValue) {
        // The optimum range stays under low
        if (theValue <= lowValue)
            return GaugeRegionOptimum;
        if (theValue <= highValue)
            return GaugeRegionSuboptimal;
        return GaugeRegionEvenLessGood;
    }

    if (highValue < optimumValue) {
        // The optimum range stays over high
        if (highValue <= theValue)
            return GaugeRegionOptimum;
        if (lowValue <= theValue)
            return GaugeRegionSuboptimal;
        return GaugeRegionEvenLessGood;
    }

    // The optimum range stays between high and low.
    // According to the standard, <meter> never show GaugeRegionEvenLessGood in this case
    // because the value is never less or greater than min or max.
    if (lowValue <= theValue && theValue <= highValue)
        return GaugeRegionOptimum;
    return GaugeRegionSuboptimal;
}

double HTMLMeterElement::valueRatio() const
{
    double min = this->min();
    double max = this->max();
    double value = this->value();

    if (max <= min)
        return 0;
    return (value - min) / (max - min);
}

void HTMLMeterElement::didElementStateChange()
{
    m_value->setWidthPercentage(valueRatio()*100);
    m_value->updatePseudo();
    if (RenderMeter* render = renderMeter())
        render->updateFromElement();
}

RenderMeter* HTMLMeterElement::renderMeter() const
{
    if (renderer() && renderer()->isMeter())
        return toRenderMeter(renderer());

    RenderObject* renderObject = userAgentShadowRoot()->firstChild()->renderer();
    return toRenderMeter(renderObject);
}

void HTMLMeterElement::didAddUserAgentShadowRoot(ShadowRoot& root)
{
    ASSERT(!m_value);

    RefPtr<MeterInnerElement> inner = MeterInnerElement::create(document());
    root.appendChild(inner);

    RefPtr<MeterBarElement> bar = MeterBarElement::create(document());
    m_value = MeterValueElement::create(document());
    m_value->setWidthPercentage(0);
    m_value->updatePseudo();
    bar->appendChild(m_value);

    inner->appendChild(bar);
}

} // namespace