third_party/WebKit/Source/core/html/HTMLProgressElement.cpp

/*
 * 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 "core/html/HTMLProgressElement.h"

#include "bindings/core/v8/ExceptionMessages.h"
#include "bindings/core/v8/ExceptionState.h"
#include "bindings/core/v8/ExceptionStatePlaceholder.h"
#include "core/HTMLNames.h"
#include "core/dom/shadow/ShadowRoot.h"
#include "core/frame/UseCounter.h"
#include "core/html/parser/HTMLParserIdioms.h"
#include "core/html/shadow/ProgressShadowElement.h"
#include "core/layout/LayoutProgress.h"
#include "core/layout/api/LayoutProgressItem.h"

namespace blink {

using namespace HTMLNames;

const double HTMLProgressElement::IndeterminatePosition = -1;
const double HTMLProgressElement::InvalidPosition = -2;

HTMLProgressElement::HTMLProgressElement(Document& document)
    : LabelableElement(progressTag, document)
    , m_value(nullptr)
{
    UseCounter::count(document, UseCounter::ProgressElement);
}

HTMLProgressElement::~HTMLProgressElement()
{
}

HTMLProgressElement* HTMLProgressElement::create(Document& document)
{
    HTMLProgressElement* progress = new HTMLProgressElement(document);
    progress->ensureUserAgentShadowRoot();
    return progress;
}

LayoutObject* HTMLProgressElement::createLayoutObject(const ComputedStyle& style)
{
    if (!style.hasAppearance()) {
        UseCounter::count(document(), UseCounter::ProgressElementWithNoneAppearance);
        return LayoutObject::createObject(this, style);
    }
    UseCounter::count(document(), UseCounter::ProgressElementWithProgressBarAppearance);
    return new LayoutProgress(this);
}

LayoutProgress* HTMLProgressElement::layoutProgress() const
{
    if (layoutObject() && layoutObject()->isProgress())
        return toLayoutProgress(layoutObject());
    return nullptr;
}

void HTMLProgressElement::parseAttribute(const QualifiedName& name, const AtomicString& oldValue, const AtomicString& value)
{
    if (name == valueAttr) {
        if (oldValue.isNull() != value.isNull())
            pseudoStateChanged(CSSSelector::PseudoIndeterminate);
        didElementStateChange();
    } else if (name == maxAttr) {
        didElementStateChange();
    } else {
        LabelableElement::parseAttribute(name, oldValue, value);
    }
}

void HTMLProgressElement::attach(const AttachContext& context)
{
    LabelableElement::attach(context);
    if (LayoutProgressItem layoutItem = LayoutProgressItem(layoutProgress()))
        layoutItem.updateFromElement();
}

double HTMLProgressElement::value() const
{
    double value = getFloatingPointAttribute(valueAttr);
    // Otherwise, if the parsed value was greater than or equal to the maximum
    // value, then the current value of the progress bar is the maximum value
    // of the progress bar. Otherwise, if parsing the value attribute's value
    // resulted in an error, or a number less than or equal to zero, then the
    // current value of the progress bar is zero.
    return !std::isfinite(value) || value < 0 ? 0 : std::min(value, max());
}

void HTMLProgressElement::setValue(double value)
{
    setFloatingPointAttribute(valueAttr, std::max(value, 0.));
}

double HTMLProgressElement::max() const
{
    double max = getFloatingPointAttribute(maxAttr);
    // Otherwise, if the element has no max attribute, or if it has one but
    // parsing it resulted in an error, or if the parsed value was less than or
    // equal to zero, then the maximum value of the progress bar is 1.0.
    return !std::isfinite(max) || max <= 0 ? 1 : max;
}

void HTMLProgressElement::setMax(double max)
{
    // FIXME: The specification says we should ignore the input value if it is inferior or equal to 0.
    setFloatingPointAttribute(maxAttr, max > 0 ? max : 1);
}

double HTMLProgressElement::position() const
{
    if (!isDeterminate())
        return HTMLProgressElement::IndeterminatePosition;
    return value() / max();
}

bool HTMLProgressElement::isDeterminate() const
{
    return fastHasAttribute(valueAttr);
}

void HTMLProgressElement::didElementStateChange()
{
    setValueWidthPercentage(position() * 100);
    if (LayoutProgressItem layoutItem = LayoutProgressItem(layoutProgress()))
        layoutItem.updateFromElement();
}

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

    ProgressShadowElement* inner = ProgressShadowElement::create(document());
    inner->setShadowPseudoId(AtomicString("-webkit-progress-inner-element"));
    root.appendChild(inner);

    ProgressShadowElement* bar = ProgressShadowElement::create(document());
    bar->setShadowPseudoId(AtomicString("-webkit-progress-bar"));
    m_value = ProgressShadowElement::create(document());
    m_value->setShadowPseudoId(AtomicString("-webkit-progress-value"));
    setValueWidthPercentage(HTMLProgressElement::IndeterminatePosition * 100);
    bar->appendChild(m_value);

    inner->appendChild(bar);
}

bool HTMLProgressElement::shouldAppearIndeterminate() const
{
    return !isDeterminate();
}

DEFINE_TRACE(HTMLProgressElement)
{
    visitor->trace(m_value);
    LabelableElement::trace(visitor);
}

void HTMLProgressElement::setValueWidthPercentage(double width) const
{
    m_value->setInlineStyleProperty(CSSPropertyWidth, width, CSSPrimitiveValue::UnitType::Percentage);
}

} // namespace blink