root/Source/core/html/shadow/SliderThumbElement.cpp

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DEFINITIONS

This source file includes following definitions.
  1. sliderPosition
  2. hasVerticalAppearance
  3. updateAppearance
  4. isSliderThumb
  5. computeLogicalHeight
  6. layout
  7. m_inDragMode
  8. create
  9. setPositionFromValue
  10. createRenderer
  11. isDisabledFormControl
  12. matchesReadOnlyPseudoClass
  13. matchesReadWritePseudoClass
  14. focusDelegate
  15. dragFrom
  16. setPositionFromPoint
  17. startDragging
  18. stopDragging
  19. defaultEventHandler
  20. willRespondToMouseMoveEvents
  21. willRespondToMouseClickEvents
  22. detach
  23. hostInput
  24. sliderThumbShadowPartId
  25. mediaSliderThumbShadowPartId
  26. shadowPseudoId
  27. create
  28. createRenderer
  29. shadowPseudoId

/*
 * Copyright (C) 2006, 2007, 2008, 2009 Apple Inc. All rights reserved.
 * Copyright (C) 2010 Google Inc. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are
 * met:
 *
 *     * Redistributions of source code must retain the above copyright
 * notice, this list of conditions and the following disclaimer.
 *     * 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.
 *     * Neither the name of Google Inc. nor the names of its
 * contributors may be used to endorse or promote products derived from
 * this software without specific prior written permission.
 *
 * 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"
#include "core/html/shadow/SliderThumbElement.h"

#include "core/events/Event.h"
#include "core/events/MouseEvent.h"
#include "core/dom/shadow/ShadowRoot.h"
#include "core/frame/LocalFrame.h"
#include "core/html/HTMLInputElement.h"
#include "core/html/forms/StepRange.h"
#include "core/html/parser/HTMLParserIdioms.h"
#include "core/html/shadow/ShadowElementNames.h"
#include "core/page/EventHandler.h"
#include "core/rendering/RenderFlexibleBox.h"
#include "core/rendering/RenderSlider.h"
#include "core/rendering/RenderTheme.h"

using namespace std;

namespace WebCore {

using namespace HTMLNames;

inline static Decimal sliderPosition(HTMLInputElement* element)
{
    const StepRange stepRange(element->createStepRange(RejectAny));
    const Decimal oldValue = parseToDecimalForNumberType(element->value(), stepRange.defaultValue());
    return stepRange.proportionFromValue(stepRange.clampValue(oldValue));
}

inline static bool hasVerticalAppearance(HTMLInputElement* input)
{
    ASSERT(input->renderer());
    RenderStyle* sliderStyle = input->renderer()->style();

    return sliderStyle->appearance() == SliderVerticalPart;
}

// --------------------------------

RenderSliderThumb::RenderSliderThumb(SliderThumbElement* element)
    : RenderBlockFlow(element)
{
}

void RenderSliderThumb::updateAppearance(RenderStyle* parentStyle)
{
    if (parentStyle->appearance() == SliderVerticalPart)
        style()->setAppearance(SliderThumbVerticalPart);
    else if (parentStyle->appearance() == SliderHorizontalPart)
        style()->setAppearance(SliderThumbHorizontalPart);
    else if (parentStyle->appearance() == MediaSliderPart)
        style()->setAppearance(MediaSliderThumbPart);
    else if (parentStyle->appearance() == MediaVolumeSliderPart)
        style()->setAppearance(MediaVolumeSliderThumbPart);
    else if (parentStyle->appearance() == MediaFullScreenVolumeSliderPart)
        style()->setAppearance(MediaFullScreenVolumeSliderThumbPart);
    if (style()->hasAppearance())
        RenderTheme::theme().adjustSliderThumbSize(style(), toElement(node()));
}

bool RenderSliderThumb::isSliderThumb() const
{
    return true;
}

// --------------------------------

// FIXME: Find a way to cascade appearance and adjust heights, and get rid of this class.
// http://webkit.org/b/62535
class RenderSliderContainer : public RenderFlexibleBox {
public:
    RenderSliderContainer(SliderContainerElement* element)
        : RenderFlexibleBox(element) { }
public:
    virtual void computeLogicalHeight(LayoutUnit logicalHeight, LayoutUnit logicalTop, LogicalExtentComputedValues&) const OVERRIDE;

private:
    virtual void layout() OVERRIDE;
};

void RenderSliderContainer::computeLogicalHeight(LayoutUnit logicalHeight, LayoutUnit logicalTop, LogicalExtentComputedValues& computedValues) const
{
    HTMLInputElement* input = toHTMLInputElement(node()->shadowHost());
    bool isVertical = hasVerticalAppearance(input);

    if (input->renderer()->isSlider() && !isVertical && input->list()) {
        int offsetFromCenter = RenderTheme::theme().sliderTickOffsetFromTrackCenter();
        LayoutUnit trackHeight = 0;
        if (offsetFromCenter < 0)
            trackHeight = -2 * offsetFromCenter;
        else {
            int tickLength = RenderTheme::theme().sliderTickSize().height();
            trackHeight = 2 * (offsetFromCenter + tickLength);
        }
        float zoomFactor = style()->effectiveZoom();
        if (zoomFactor != 1.0)
            trackHeight *= zoomFactor;

        RenderBox::computeLogicalHeight(trackHeight, logicalTop, computedValues);
        return;
    }
    if (isVertical)
        logicalHeight = RenderSlider::defaultTrackLength;
    RenderBox::computeLogicalHeight(logicalHeight, logicalTop, computedValues);
}

void RenderSliderContainer::layout()
{
    HTMLInputElement* input = toHTMLInputElement(node()->shadowHost());
    bool isVertical = hasVerticalAppearance(input);
    style()->setFlexDirection(isVertical ? FlowColumn : FlowRow);
    TextDirection oldTextDirection = style()->direction();
    if (isVertical) {
        // FIXME: Work around rounding issues in RTL vertical sliders. We want them to
        // render identically to LTR vertical sliders. We can remove this work around when
        // subpixel rendering is enabled on all ports.
        style()->setDirection(LTR);
    }

    Element* thumbElement = input->userAgentShadowRoot()->getElementById(ShadowElementNames::sliderThumb());
    Element* trackElement = input->userAgentShadowRoot()->getElementById(ShadowElementNames::sliderTrack());
    RenderBox* thumb = thumbElement ? thumbElement->renderBox() : 0;
    RenderBox* track = trackElement ? trackElement->renderBox() : 0;

    SubtreeLayoutScope layoutScope(this);
    // Force a layout to reset the position of the thumb so the code below doesn't move the thumb to the wrong place.
    // FIXME: Make a custom Render class for the track and move the thumb positioning code there.
    if (track)
        layoutScope.setChildNeedsLayout(track);

    RenderFlexibleBox::layout();

    style()->setDirection(oldTextDirection);
    // These should always exist, unless someone mutates the shadow DOM (e.g., in the inspector).
    if (!thumb || !track)
        return;

    double percentageOffset = sliderPosition(input).toDouble();
    LayoutUnit availableExtent = isVertical ? track->contentHeight() : track->contentWidth();
    availableExtent -= isVertical ? thumb->height() : thumb->width();
    LayoutUnit offset = percentageOffset * availableExtent;
    LayoutPoint thumbLocation = thumb->location();
    if (isVertical)
        thumbLocation.setY(thumbLocation.y() + track->contentHeight() - thumb->height() - offset);
    else if (style()->isLeftToRightDirection())
        thumbLocation.setX(thumbLocation.x() + offset);
    else
        thumbLocation.setX(thumbLocation.x() - offset);
    thumb->setLocation(thumbLocation);
    if (checkForRepaintDuringLayout() && parent()
        && (parent()->style()->appearance() == MediaVolumeSliderPart || parent()->style()->appearance() == MediaSliderPart)) {
        // This will sometimes repaint too much. However, it is necessary to
        // correctly repaint media controls (volume and timeline sliders) -
        // they have special painting code in RenderMediaControls.cpp:paintMediaVolumeSlider
        // and paintMediaSlider that gets called via -webkit-appearance and RenderTheme,
        // so nothing else would otherwise invalidate the slider.
        repaint();
    }
}

// --------------------------------

inline SliderThumbElement::SliderThumbElement(Document& document)
    : HTMLDivElement(document)
    , m_inDragMode(false)
{
}

PassRefPtr<SliderThumbElement> SliderThumbElement::create(Document& document)
{
    RefPtr<SliderThumbElement> element = adoptRef(new SliderThumbElement(document));
    element->setAttribute(idAttr, ShadowElementNames::sliderThumb());
    return element.release();
}

void SliderThumbElement::setPositionFromValue()
{
    // Since the code to calculate position is in the RenderSliderThumb layout
    // path, we don't actually update the value here. Instead, we poke at the
    // renderer directly to trigger layout.
    if (renderer())
        renderer()->setNeedsLayout();
}

RenderObject* SliderThumbElement::createRenderer(RenderStyle*)
{
    return new RenderSliderThumb(this);
}

bool SliderThumbElement::isDisabledFormControl() const
{
    return hostInput() && hostInput()->isDisabledFormControl();
}

bool SliderThumbElement::matchesReadOnlyPseudoClass() const
{
    return hostInput() && hostInput()->matchesReadOnlyPseudoClass();
}

bool SliderThumbElement::matchesReadWritePseudoClass() const
{
    return hostInput() && hostInput()->matchesReadWritePseudoClass();
}

Node* SliderThumbElement::focusDelegate()
{
    return hostInput();
}

void SliderThumbElement::dragFrom(const LayoutPoint& point)
{
    RefPtr<SliderThumbElement> protector(this);
    startDragging();
    setPositionFromPoint(point);
}

void SliderThumbElement::setPositionFromPoint(const LayoutPoint& point)
{
    RefPtr<HTMLInputElement> input(hostInput());
    Element* trackElement = input->userAgentShadowRoot()->getElementById(ShadowElementNames::sliderTrack());

    if (!input->renderer() || !renderBox() || !trackElement->renderBox())
        return;

    LayoutPoint offset = roundedLayoutPoint(input->renderer()->absoluteToLocal(point, UseTransforms));
    bool isVertical = hasVerticalAppearance(input.get());
    bool isLeftToRightDirection = renderBox()->style()->isLeftToRightDirection();
    LayoutUnit trackSize;
    LayoutUnit position;
    LayoutUnit currentPosition;
    // We need to calculate currentPosition from absolute points becaue the
    // renderer for this node is usually on a layer and renderBox()->x() and
    // y() are unusable.
    // FIXME: This should probably respect transforms.
    LayoutPoint absoluteThumbOrigin = renderBox()->absoluteBoundingBoxRectIgnoringTransforms().location();
    LayoutPoint absoluteSliderContentOrigin = roundedLayoutPoint(input->renderer()->localToAbsolute());
    IntRect trackBoundingBox = trackElement->renderer()->absoluteBoundingBoxRectIgnoringTransforms();
    IntRect inputBoundingBox = input->renderer()->absoluteBoundingBoxRectIgnoringTransforms();
    if (isVertical) {
        trackSize = trackElement->renderBox()->contentHeight() - renderBox()->height();
        position = offset.y() - renderBox()->height() / 2 - trackBoundingBox.y() + inputBoundingBox.y() - renderBox()->marginBottom();
        currentPosition = absoluteThumbOrigin.y() - absoluteSliderContentOrigin.y();
    } else {
        trackSize = trackElement->renderBox()->contentWidth() - renderBox()->width();
        position = offset.x() - renderBox()->width() / 2 - trackBoundingBox.x() + inputBoundingBox.x();
        position -= isLeftToRightDirection ? renderBox()->marginLeft() : renderBox()->marginRight();
        currentPosition = absoluteThumbOrigin.x() - absoluteSliderContentOrigin.x();
    }
    position = max<LayoutUnit>(0, min(position, trackSize));
    const Decimal ratio = Decimal::fromDouble(static_cast<double>(position) / trackSize);
    const Decimal fraction = isVertical || !isLeftToRightDirection ? Decimal(1) - ratio : ratio;
    StepRange stepRange(input->createStepRange(RejectAny));
    Decimal value = stepRange.clampValue(stepRange.valueFromProportion(fraction));

    Decimal closest = input->findClosestTickMarkValue(value);
    if (closest.isFinite()) {
        double closestFraction = stepRange.proportionFromValue(closest).toDouble();
        double closestRatio = isVertical || !isLeftToRightDirection ? 1.0 - closestFraction : closestFraction;
        LayoutUnit closestPosition = trackSize * closestRatio;
        const LayoutUnit snappingThreshold = 5;
        if ((closestPosition - position).abs() <= snappingThreshold)
            value = closest;
    }

    String valueString = serializeForNumberType(value);
    if (valueString == input->value())
        return;

    // FIXME: This is no longer being set from renderer. Consider updating the method name.
    input->setValueFromRenderer(valueString);
    if (renderer())
        renderer()->setNeedsLayout();
}

void SliderThumbElement::startDragging()
{
    if (LocalFrame* frame = document().frame()) {
        frame->eventHandler().setCapturingMouseEventsNode(this);
        m_inDragMode = true;
    }
}

void SliderThumbElement::stopDragging()
{
    if (!m_inDragMode)
        return;

    if (LocalFrame* frame = document().frame())
        frame->eventHandler().setCapturingMouseEventsNode(nullptr);
    m_inDragMode = false;
    if (renderer())
        renderer()->setNeedsLayout();
    if (hostInput())
        hostInput()->dispatchFormControlChangeEvent();
}

void SliderThumbElement::defaultEventHandler(Event* event)
{
    if (!event->isMouseEvent()) {
        HTMLDivElement::defaultEventHandler(event);
        return;
    }

    // FIXME: Should handle this readonly/disabled check in more general way.
    // Missing this kind of check is likely to occur elsewhere if adding it in each shadow element.
    HTMLInputElement* input = hostInput();
    if (!input || input->isDisabledOrReadOnly()) {
        stopDragging();
        HTMLDivElement::defaultEventHandler(event);
        return;
    }

    MouseEvent* mouseEvent = toMouseEvent(event);
    bool isLeftButton = mouseEvent->button() == LeftButton;
    const AtomicString& eventType = event->type();

    // We intentionally do not call event->setDefaultHandled() here because
    // MediaControlTimelineElement::defaultEventHandler() wants to handle these
    // mouse events.
    if (eventType == EventTypeNames::mousedown && isLeftButton) {
        startDragging();
        return;
    } else if (eventType == EventTypeNames::mouseup && isLeftButton) {
        stopDragging();
        return;
    } else if (eventType == EventTypeNames::mousemove) {
        if (m_inDragMode)
            setPositionFromPoint(mouseEvent->absoluteLocation());
        return;
    }

    HTMLDivElement::defaultEventHandler(event);
}

bool SliderThumbElement::willRespondToMouseMoveEvents()
{
    const HTMLInputElement* input = hostInput();
    if (input && !input->isDisabledOrReadOnly() && m_inDragMode)
        return true;

    return HTMLDivElement::willRespondToMouseMoveEvents();
}

bool SliderThumbElement::willRespondToMouseClickEvents()
{
    const HTMLInputElement* input = hostInput();
    if (input && !input->isDisabledOrReadOnly())
        return true;

    return HTMLDivElement::willRespondToMouseClickEvents();
}

void SliderThumbElement::detach(const AttachContext& context)
{
    if (m_inDragMode) {
        if (LocalFrame* frame = document().frame())
            frame->eventHandler().setCapturingMouseEventsNode(nullptr);
    }
    HTMLDivElement::detach(context);
}

HTMLInputElement* SliderThumbElement::hostInput() const
{
    // Only HTMLInputElement creates SliderThumbElement instances as its shadow nodes.
    // So, shadowHost() must be an HTMLInputElement.
    return toHTMLInputElement(shadowHost());
}

static const AtomicString& sliderThumbShadowPartId()
{
    DEFINE_STATIC_LOCAL(const AtomicString, sliderThumb, ("-webkit-slider-thumb", AtomicString::ConstructFromLiteral));
    return sliderThumb;
}

static const AtomicString& mediaSliderThumbShadowPartId()
{
    DEFINE_STATIC_LOCAL(const AtomicString, mediaSliderThumb, ("-webkit-media-slider-thumb", AtomicString::ConstructFromLiteral));
    return mediaSliderThumb;
}

const AtomicString& SliderThumbElement::shadowPseudoId() const
{
    HTMLInputElement* input = hostInput();
    if (!input || !input->renderer())
        return sliderThumbShadowPartId();

    RenderStyle* sliderStyle = input->renderer()->style();
    switch (sliderStyle->appearance()) {
    case MediaSliderPart:
    case MediaSliderThumbPart:
    case MediaVolumeSliderPart:
    case MediaVolumeSliderThumbPart:
    case MediaFullScreenVolumeSliderPart:
    case MediaFullScreenVolumeSliderThumbPart:
        return mediaSliderThumbShadowPartId();
    default:
        return sliderThumbShadowPartId();
    }
}

// --------------------------------

inline SliderContainerElement::SliderContainerElement(Document& document)
    : HTMLDivElement(document)
{
}

PassRefPtr<SliderContainerElement> SliderContainerElement::create(Document& document)
{
    return adoptRef(new SliderContainerElement(document));
}

RenderObject* SliderContainerElement::createRenderer(RenderStyle*)
{
    return new RenderSliderContainer(this);
}

const AtomicString& SliderContainerElement::shadowPseudoId() const
{
    DEFINE_STATIC_LOCAL(const AtomicString, mediaSliderContainer, ("-webkit-media-slider-container", AtomicString::ConstructFromLiteral));
    DEFINE_STATIC_LOCAL(const AtomicString, sliderContainer, ("-webkit-slider-container", AtomicString::ConstructFromLiteral));

    if (!shadowHost() || !shadowHost()->renderer())
        return sliderContainer;

    RenderStyle* sliderStyle = shadowHost()->renderer()->style();
    switch (sliderStyle->appearance()) {
    case MediaSliderPart:
    case MediaSliderThumbPart:
    case MediaVolumeSliderPart:
    case MediaVolumeSliderThumbPart:
    case MediaFullScreenVolumeSliderPart:
    case MediaFullScreenVolumeSliderThumbPart:
        return mediaSliderContainer;
    default:
        return sliderContainer;
    }
}

}

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