Source/core/html/RangeInputType.cpp

/*
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 * Copyright (C) 2011 Apple Inc. All rights reserved.
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#include "config.h"
#include "core/html/RangeInputType.h"

#include <limits>
#include "HTMLNames.h"
#include "bindings/v8/ExceptionStatePlaceholder.h"
#include "core/accessibility/AXObjectCache.h"
#include "core/dom/KeyboardEvent.h"
#include "core/dom/MouseEvent.h"
#include "core/dom/ScopedEventQueue.h"
#include "core/dom/Touch.h"
#include "core/dom/TouchEvent.h"
#include "core/dom/TouchList.h"
#include "core/dom/shadow/ShadowRoot.h"
#include "core/html/HTMLDataListElement.h"
#include "core/html/HTMLDivElement.h"
#include "core/html/HTMLInputElement.h"
#include "core/html/HTMLOptionElement.h"
#include "core/html/InputTypeNames.h"
#include "core/html/StepRange.h"
#include "core/html/parser/HTMLParserIdioms.h"
#include "core/html/shadow/ShadowElementNames.h"
#include "core/html/shadow/SliderThumbElement.h"
#include "core/platform/PlatformMouseEvent.h"
#include "core/rendering/RenderSlider.h"
#include "wtf/MathExtras.h"
#include "wtf/NonCopyingSort.h"
#include "wtf/PassOwnPtr.h"

namespace WebCore {

using namespace HTMLNames;
using namespace std;

static const int rangeDefaultMinimum = 0;
static const int rangeDefaultMaximum = 100;
static const int rangeDefaultStep = 1;
static const int rangeDefaultStepBase = 0;
static const int rangeStepScaleFactor = 1;

static Decimal ensureMaximum(const Decimal& proposedValue, const Decimal& minimum, const Decimal& fallbackValue)
{
    return proposedValue >= minimum ? proposedValue : std::max(minimum, fallbackValue);
}

PassOwnPtr<InputType> RangeInputType::create(HTMLInputElement* element)
{
    return adoptPtr(new RangeInputType(element));
}

RangeInputType::RangeInputType(HTMLInputElement* element)
    : InputType(element)
    , m_tickMarkValuesDirty(true)
{
}

void RangeInputType::countUsage()
{
    observeFeatureIfVisible(UseCounter::InputTypeRange);
}

bool RangeInputType::isRangeControl() const
{
    return true;
}

const AtomicString& RangeInputType::formControlType() const
{
    return InputTypeNames::range();
}

double RangeInputType::valueAsDouble() const
{
    return parseToDoubleForNumberType(element()->value());
}

void RangeInputType::setValueAsDecimal(const Decimal& newValue, TextFieldEventBehavior eventBehavior, ExceptionState&) const
{
    element()->setValue(serialize(newValue), eventBehavior);
}

bool RangeInputType::typeMismatchFor(const String& value) const
{
    return !value.isEmpty() && !std::isfinite(parseToDoubleForNumberType(value));
}

bool RangeInputType::supportsRequired() const
{
    return false;
}

StepRange RangeInputType::createStepRange(AnyStepHandling anyStepHandling) const
{
    DEFINE_STATIC_LOCAL(const StepRange::StepDescription, stepDescription, (rangeDefaultStep, rangeDefaultStepBase, rangeStepScaleFactor));

    const Decimal minimum = parseToNumber(element()->fastGetAttribute(minAttr), rangeDefaultMinimum);
    const Decimal maximum = ensureMaximum(parseToNumber(element()->fastGetAttribute(maxAttr), rangeDefaultMaximum), minimum, rangeDefaultMaximum);

    const AtomicString& precisionValue = element()->fastGetAttribute(precisionAttr);
    if (!precisionValue.isNull()) {
        const Decimal step = equalIgnoringCase(precisionValue, "float") ? Decimal::nan() : 1;
        return StepRange(minimum, minimum, maximum, step, stepDescription);
    }

    const Decimal step = StepRange::parseStep(anyStepHandling, stepDescription, element()->fastGetAttribute(stepAttr));
    return StepRange(minimum, minimum, maximum, step, stepDescription);
}

bool RangeInputType::isSteppable() const
{
    return true;
}

void RangeInputType::handleMouseDownEvent(MouseEvent* event)
{
    if (element()->isDisabledOrReadOnly())
        return;

    Node* targetNode = event->target()->toNode();
    if (event->button() != LeftButton || !targetNode)
        return;
    ASSERT(element()->shadow());
    if (targetNode != element() && !targetNode->isDescendantOf(element()->userAgentShadowRoot()))
        return;
    SliderThumbElement* thumb = sliderThumbElement();
    if (targetNode == thumb)
        return;
    thumb->dragFrom(event->absoluteLocation());
}

void RangeInputType::handleTouchEvent(TouchEvent* event)
{
    if (element()->isDisabledOrReadOnly())
        return;

    if (event->type() == eventNames().touchendEvent) {
        event->setDefaultHandled();
        return;
    }

    TouchList* touches = event->targetTouches();
    if (touches->length() == 1) {
        sliderThumbElement()->setPositionFromPoint(touches->item(0)->absoluteLocation());
        event->setDefaultHandled();
    }
}

bool RangeInputType::hasTouchEventHandler() const
{
    return true;
}

void RangeInputType::handleKeydownEvent(KeyboardEvent* event)
{
    if (element()->isDisabledOrReadOnly())
        return;

    const String& key = event->keyIdentifier();

    const Decimal current = parseToNumberOrNaN(element()->value());
    ASSERT(current.isFinite());

    StepRange stepRange(createStepRange(RejectAny));


    // FIXME: We can't use stepUp() for the step value "any". So, we increase
    // or decrease the value by 1/100 of the value range. Is it reasonable?
    const Decimal step = equalIgnoringCase(element()->fastGetAttribute(stepAttr), "any") ? (stepRange.maximum() - stepRange.minimum()) / 100 : stepRange.step();
    const Decimal bigStep = max((stepRange.maximum() - stepRange.minimum()) / 10, step);

    bool isVertical = false;
    if (element()->renderer()) {
        ControlPart part = element()->renderer()->style()->appearance();
        isVertical = part == SliderVerticalPart || part == MediaVolumeSliderPart;
    }

    Decimal newValue;
    if (key == "Up")
        newValue = current + step;
    else if (key == "Down")
        newValue = current - step;
    else if (key == "Left")
        newValue = isVertical ? current + step : current - step;
    else if (key == "Right")
        newValue = isVertical ? current - step : current + step;
    else if (key == "PageUp")
        newValue = current + bigStep;
    else if (key == "PageDown")
        newValue = current - bigStep;
    else if (key == "Home")
        newValue = isVertical ? stepRange.maximum() : stepRange.minimum();
    else if (key == "End")
        newValue = isVertical ? stepRange.minimum() : stepRange.maximum();
    else
        return; // Did not match any key binding.

    newValue = stepRange.clampValue(newValue);

    if (newValue != current) {
        EventQueueScope scope;
        TextFieldEventBehavior eventBehavior = DispatchChangeEvent;
        setValueAsDecimal(newValue, eventBehavior, IGNORE_EXCEPTION);

        if (AXObjectCache* cache = element()->document()->existingAXObjectCache())
            cache->postNotification(element(), AXObjectCache::AXValueChanged, true);
        element()->dispatchFormControlChangeEvent();
    }

    event->setDefaultHandled();
}

void RangeInputType::createShadowSubtree()
{
    ASSERT(element()->shadow());

    Document* document = element()->document();
    RefPtr<HTMLDivElement> track = HTMLDivElement::create(document);
    track->setPart(AtomicString("-webkit-slider-runnable-track", AtomicString::ConstructFromLiteral));
    track->setAttribute(idAttr, ShadowElementNames::sliderTrack());
    track->appendChild(SliderThumbElement::create(document));
    RefPtr<HTMLElement> container = SliderContainerElement::create(document);
    container->appendChild(track.release());
    element()->userAgentShadowRoot()->appendChild(container.release());
}

RenderObject* RangeInputType::createRenderer(RenderStyle*) const
{
    return new RenderSlider(element());
}

Decimal RangeInputType::parseToNumber(const String& src, const Decimal& defaultValue) const
{
    return parseToDecimalForNumberType(src, defaultValue);
}

String RangeInputType::serialize(const Decimal& value) const
{
    if (!value.isFinite())
        return String();
    return serializeForNumberType(value);
}

// FIXME: Could share this with BaseClickableWithKeyInputType and BaseCheckableInputType if we had a common base class.
void RangeInputType::accessKeyAction(bool sendMouseEvents)
{
    InputType::accessKeyAction(sendMouseEvents);

    element()->dispatchSimulatedClick(0, sendMouseEvents ? SendMouseUpDownEvents : SendNoEvents);
}

void RangeInputType::sanitizeValueInResponseToMinOrMaxAttributeChange()
{
    if (element()->hasDirtyValue())
        element()->setValue(element()->value());

    sliderThumbElement()->setPositionFromValue();
}

void RangeInputType::setValue(const String& value, bool valueChanged, TextFieldEventBehavior eventBehavior)
{
    InputType::setValue(value, valueChanged, eventBehavior);

    if (!valueChanged)
        return;

    sliderThumbElement()->setPositionFromValue();
}

String RangeInputType::fallbackValue() const
{
    return serializeForNumberType(createStepRange(RejectAny).defaultValue());
}

String RangeInputType::sanitizeValue(const String& proposedValue) const
{
    StepRange stepRange(createStepRange(RejectAny));
    const Decimal proposedNumericValue = parseToNumber(proposedValue, stepRange.defaultValue());
    return serializeForNumberType(stepRange.clampValue(proposedNumericValue));
}

bool RangeInputType::shouldRespectListAttribute()
{
    return InputType::themeSupportsDataListUI(this);
}

inline SliderThumbElement* RangeInputType::sliderThumbElement() const
{
    return toSliderThumbElement(element()->userAgentShadowRoot()->getElementById(ShadowElementNames::sliderThumb()));
}

inline Element* RangeInputType::sliderTrackElement() const
{
    return element()->userAgentShadowRoot()->getElementById(ShadowElementNames::sliderTrack());
}

void RangeInputType::listAttributeTargetChanged()
{
    m_tickMarkValuesDirty = true;
    Element* sliderTrackElement = this->sliderTrackElement();
    if (sliderTrackElement->renderer())
        sliderTrackElement->renderer()->setNeedsLayout();
}

static bool decimalCompare(const Decimal& a, const Decimal& b)
{
    return a < b;
}

void RangeInputType::updateTickMarkValues()
{
    if (!m_tickMarkValuesDirty)
        return;
    m_tickMarkValues.clear();
    m_tickMarkValuesDirty = false;
    HTMLDataListElement* dataList = element()->dataList();
    if (!dataList)
        return;
    RefPtr<HTMLCollection> options = dataList->options();
    m_tickMarkValues.reserveCapacity(options->length());
    for (unsigned i = 0; i < options->length(); ++i) {
        Node* node = options->item(i);
        HTMLOptionElement* optionElement = toHTMLOptionElement(node);
        String optionValue = optionElement->value();
        if (!element()->isValidValue(optionValue))
            continue;
        m_tickMarkValues.append(parseToNumber(optionValue, Decimal::nan()));
    }
    m_tickMarkValues.shrinkToFit();
    nonCopyingSort(m_tickMarkValues.begin(), m_tickMarkValues.end(), decimalCompare);
}

Decimal RangeInputType::findClosestTickMarkValue(const Decimal& value)
{
    updateTickMarkValues();
    if (!m_tickMarkValues.size())
        return Decimal::nan();

    size_t left = 0;
    size_t right = m_tickMarkValues.size();
    size_t middle;
    while (true) {
        ASSERT(left <= right);
        middle = left + (right - left) / 2;
        if (!middle)
            break;
        if (middle == m_tickMarkValues.size() - 1 && m_tickMarkValues[middle] < value) {
            middle++;
            break;
        }
        if (m_tickMarkValues[middle - 1] <= value && m_tickMarkValues[middle] >= value)
            break;

        if (m_tickMarkValues[middle] < value)
            left = middle;
        else
            right = middle;
    }
    const Decimal closestLeft = middle ? m_tickMarkValues[middle - 1] : Decimal::infinity(Decimal::Negative);
    const Decimal closestRight = middle != m_tickMarkValues.size() ? m_tickMarkValues[middle] : Decimal::infinity(Decimal::Positive);
    if (closestRight - value < value - closestLeft)
        return closestRight;
    return closestLeft;
}

} // namespace WebCore