Source/core/rendering/RenderListBox.cpp

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This source file includes following definitions.
m_indexOffset
isChildAllowed
selectElement
updateFromElement
selectionChanged
layout
scrollToRevealSelection
computeIntrinsicLogicalWidths
computePreferredLogicalWidths
size
numVisibleItems
numItems
listHeight
computeLogicalHeight
baselinePosition
itemBoundingBoxRect
paintObject
addFocusRingRects
scrollbarLeft
paintScrollbar
itemOffsetForAlignment
paintItemForeground
paintItemBackground
isPointInOverflowControl
listIndexAtOffset
panScroll
scrollToward
autoscroll
stopAutoscroll
scrollToRevealElementAtListIndex
listIndexIsVisible
scroll
scrollSize
scrollPosition
setScrollOffset
scrollTo
itemHeight
verticalScrollbarWidth
scrollWidth
scrollHeight
scrollLeft
setScrollLeft
scrollTop
setScrollTop
nodeAtPoint
controlClipRect
isActive
invalidateScrollbarRect
repaintScrollbarIfNeeded
convertFromScrollbarToContainingView
convertFromContainingViewToScrollbar
convertFromScrollbarToContainingView
convertFromContainingViewToScrollbar
contentsSize
visibleHeight
visibleWidth
lastKnownMousePosition
shouldSuspendScrollAnimations
scrollbarsCanBeActive
minimumScrollPosition
maximumScrollPosition
userInputScrollable
shouldPlaceVerticalScrollbarOnLeft
lineStep
pageStep
pixelStep
scrollableAreaBoundingBox
createScrollbar
destroyScrollbar
setHasVerticalScrollbar
/*
 * Copyright (C) 2006, 2007, 2008, 2011 Apple Inc. All rights reserved.
 *               2009 Torch Mobile Inc. All rights reserved. (http://www.torchmobile.com/)
 *
 * 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.
 * 3.  Neither the name of Apple Computer, Inc. ("Apple") 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 APPLE AND ITS 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 APPLE OR ITS 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/rendering/RenderListBox.h"

#include <math.h>
#include "HTMLNames.h"
#include "core/accessibility/AXObjectCache.h"
#include "core/css/CSSFontSelector.h"
#include "core/css/resolver/StyleResolver.h"
#include "core/dom/Document.h"
#include "core/dom/NodeRenderStyle.h"
#include "core/editing/FrameSelection.h"
#include "core/frame/FrameView.h"
#include "core/frame/LocalFrame.h"
#include "core/html/HTMLOptGroupElement.h"
#include "core/html/HTMLOptionElement.h"
#include "core/html/HTMLSelectElement.h"
#include "core/page/EventHandler.h"
#include "core/page/FocusController.h"
#include "core/page/Page.h"
#include "core/page/SpatialNavigation.h"
#include "core/rendering/HitTestResult.h"
#include "core/rendering/LayoutRectRecorder.h"
#include "core/rendering/PaintInfo.h"
#include "core/rendering/RenderScrollbar.h"
#include "core/rendering/RenderText.h"
#include "core/rendering/RenderTheme.h"
#include "core/rendering/RenderView.h"
#include "platform/fonts/FontCache.h"
#include "platform/graphics/GraphicsContext.h"
#include "platform/scroll/Scrollbar.h"
#include "platform/text/BidiTextRun.h"

using namespace std;

namespace WebCore {

using namespace HTMLNames;

const int rowSpacing = 1;

const int optionsSpacingHorizontal = 2;

// The minSize constant was originally defined to render scrollbars correctly.
// This might vary for different platforms.
const int minSize = 4;

// Default size when the multiple attribute is present but size attribute is absent.
const int defaultSize = 4;

// FIXME: This hardcoded baselineAdjustment is what we used to do for the old
// widget, but I'm not sure this is right for the new control.
const int baselineAdjustment = 7;

RenderListBox::RenderListBox(Element* element)
    : RenderBlockFlow(element)
    , m_optionsChanged(true)
    , m_scrollToRevealSelectionAfterLayout(true)
    , m_inAutoscroll(false)
    , m_optionsWidth(0)
    , m_indexOffset(0)
{
    ASSERT(element);
    ASSERT(element->isHTMLElement());
    ASSERT(isHTMLSelectElement(element));

    if (FrameView* frameView = frame()->view())
        frameView->addScrollableArea(this);
}

RenderListBox::~RenderListBox()
{
    setHasVerticalScrollbar(false);

    if (FrameView* frameView = frame()->view())
        frameView->removeScrollableArea(this);
}

// FIXME: Instead of this hack we should add a ShadowRoot to <select> with no insertion point
// to prevent children from rendering.
bool RenderListBox::isChildAllowed(RenderObject* object, RenderStyle*) const
{
    return object->isAnonymous() && !object->isRenderFullScreen();
}

inline HTMLSelectElement* RenderListBox::selectElement() const
{
    return toHTMLSelectElement(node());
}

void RenderListBox::updateFromElement()
{
    FontCachePurgePreventer fontCachePurgePreventer;

    if (m_optionsChanged) {
        const Vector<HTMLElement*>& listItems = selectElement()->listItems();
        int size = numItems();

        float width = 0;
        for (int i = 0; i < size; ++i) {
            HTMLElement* element = listItems[i];
            String text;
            Font itemFont = style()->font();
            if (isHTMLOptionElement(*element)) {
                text = toHTMLOptionElement(*element).textIndentedToRespectGroupLabel();
            } else if (isHTMLOptGroupElement(*element)) {
                text = toHTMLOptGroupElement(*element).groupLabelText();
                FontDescription d = itemFont.fontDescription();
                d.setWeight(d.bolderWeight());
                itemFont = Font(d);
                itemFont.update(document().styleEngine()->fontSelector());
            }

            if (!text.isEmpty()) {
                applyTextTransform(style(), text, ' ');

                bool hasStrongDirectionality;
                TextDirection direction = determineDirectionality(text, hasStrongDirectionality);
                TextRun textRun = constructTextRun(this, itemFont, text, style(), TextRun::AllowTrailingExpansion);
                if (hasStrongDirectionality)
                    textRun.setDirection(direction);
                textRun.disableRoundingHacks();
                float textWidth = itemFont.width(textRun);
                width = max(width, textWidth);
            }
        }
        m_optionsWidth = static_cast<int>(ceilf(width));
        m_optionsChanged = false;

        setHasVerticalScrollbar(true);

        setNeedsLayoutAndPrefWidthsRecalc();
    }
}

void RenderListBox::selectionChanged()
{
    repaint();
    if (!m_inAutoscroll) {
        if (m_optionsChanged || needsLayout())
            m_scrollToRevealSelectionAfterLayout = true;
        else
            scrollToRevealSelection();
    }

    if (AXObjectCache* cache = document().existingAXObjectCache())
        cache->selectedChildrenChanged(this);
}

void RenderListBox::layout()
{
    LayoutRectRecorder recorder(*this);
    RenderBlockFlow::layout();

    if (m_vBar) {
        bool enabled = numVisibleItems() < numItems();
        m_vBar->setEnabled(enabled);
        m_vBar->setProportion(numVisibleItems(), numItems());
        if (!enabled) {
            scrollToOffsetWithoutAnimation(VerticalScrollbar, 0);
            m_indexOffset = 0;
        }
    }

    if (m_scrollToRevealSelectionAfterLayout) {
        LayoutStateDisabler layoutStateDisabler(*this);
        scrollToRevealSelection();
    }
}

void RenderListBox::scrollToRevealSelection()
{
    HTMLSelectElement* select = selectElement();

    m_scrollToRevealSelectionAfterLayout = false;

    int firstIndex = select->activeSelectionStartListIndex();
    if (firstIndex >= 0 && !listIndexIsVisible(select->activeSelectionEndListIndex()))
        scrollToRevealElementAtListIndex(firstIndex);
}

void RenderListBox::computeIntrinsicLogicalWidths(LayoutUnit& minLogicalWidth, LayoutUnit& maxLogicalWidth) const
{
    maxLogicalWidth = m_optionsWidth + 2 * optionsSpacingHorizontal;
    if (m_vBar)
        maxLogicalWidth += verticalScrollbarWidth();
    if (!style()->width().isPercent())
        minLogicalWidth = maxLogicalWidth;
}

void RenderListBox::computePreferredLogicalWidths()
{
    ASSERT(!m_optionsChanged);

    m_minPreferredLogicalWidth = 0;
    m_maxPreferredLogicalWidth = 0;

    if (style()->width().isFixed() && style()->width().value() > 0)
        m_minPreferredLogicalWidth = m_maxPreferredLogicalWidth = adjustContentBoxLogicalWidthForBoxSizing(style()->width().value());
    else
        computeIntrinsicLogicalWidths(m_minPreferredLogicalWidth, m_maxPreferredLogicalWidth);

    if (style()->minWidth().isFixed() && style()->minWidth().value() > 0) {
        m_maxPreferredLogicalWidth = max(m_maxPreferredLogicalWidth, adjustContentBoxLogicalWidthForBoxSizing(style()->minWidth().value()));
        m_minPreferredLogicalWidth = max(m_minPreferredLogicalWidth, adjustContentBoxLogicalWidthForBoxSizing(style()->minWidth().value()));
    }

    if (style()->maxWidth().isFixed()) {
        m_maxPreferredLogicalWidth = min(m_maxPreferredLogicalWidth, adjustContentBoxLogicalWidthForBoxSizing(style()->maxWidth().value()));
        m_minPreferredLogicalWidth = min(m_minPreferredLogicalWidth, adjustContentBoxLogicalWidthForBoxSizing(style()->maxWidth().value()));
    }

    LayoutUnit toAdd = borderAndPaddingWidth();
    m_minPreferredLogicalWidth += toAdd;
    m_maxPreferredLogicalWidth += toAdd;

    clearPreferredLogicalWidthsDirty();
}

int RenderListBox::size() const
{
    int specifiedSize = selectElement()->size();
    if (specifiedSize > 1)
        return max(minSize, specifiedSize);

    return defaultSize;
}

int RenderListBox::numVisibleItems() const
{
    // Only count fully visible rows. But don't return 0 even if only part of a row shows.
    return max<int>(1, (contentHeight() + rowSpacing) / itemHeight());
}

int RenderListBox::numItems() const
{
    return selectElement()->listItems().size();
}

LayoutUnit RenderListBox::listHeight() const
{
    return itemHeight() * numItems() - rowSpacing;
}

void RenderListBox::computeLogicalHeight(LayoutUnit, LayoutUnit logicalTop, LogicalExtentComputedValues& computedValues) const
{
    LayoutUnit height = itemHeight() * size() - rowSpacing + borderAndPaddingHeight();
    RenderBox::computeLogicalHeight(height, logicalTop, computedValues);
}

int RenderListBox::baselinePosition(FontBaseline baselineType, bool firstLine, LineDirectionMode lineDirection, LinePositionMode linePositionMode) const
{
    return RenderBox::baselinePosition(baselineType, firstLine, lineDirection, linePositionMode) - baselineAdjustment;
}

LayoutRect RenderListBox::itemBoundingBoxRect(const LayoutPoint& additionalOffset, int index)
{
    // For RTL, items start after the left-side vertical scrollbar.
    int scrollbarOffset = style()->shouldPlaceBlockDirectionScrollbarOnLogicalLeft() ? verticalScrollbarWidth() : 0;
    return LayoutRect(additionalOffset.x() + borderLeft() + paddingLeft() + scrollbarOffset,
        additionalOffset.y() + borderTop() + paddingTop() + itemHeight() * (index - m_indexOffset),
        contentWidth(), itemHeight());
}

void RenderListBox::paintObject(PaintInfo& paintInfo, const LayoutPoint& paintOffset)
{
    if (style()->visibility() != VISIBLE)
        return;

    int listItemsSize = numItems();

    if (paintInfo.phase == PaintPhaseForeground) {
        int index = m_indexOffset;
        while (index < listItemsSize && index <= m_indexOffset + numVisibleItems()) {
            paintItemForeground(paintInfo, paintOffset, index);
            index++;
        }
    }

    // Paint the children.
    RenderBlockFlow::paintObject(paintInfo, paintOffset);

    switch (paintInfo.phase) {
    // Depending on whether we have overlay scrollbars they
    // get rendered in the foreground or background phases
    case PaintPhaseForeground:
        if (m_vBar->isOverlayScrollbar())
            paintScrollbar(paintInfo, paintOffset);
        break;
    case PaintPhaseBlockBackground:
        if (!m_vBar->isOverlayScrollbar())
            paintScrollbar(paintInfo, paintOffset);
        break;
    case PaintPhaseChildBlockBackground:
    case PaintPhaseChildBlockBackgrounds: {
        int index = m_indexOffset;
        while (index < listItemsSize && index <= m_indexOffset + numVisibleItems()) {
            paintItemBackground(paintInfo, paintOffset, index);
            index++;
        }
        break;
    }
    default:
        break;
    }
}

void RenderListBox::addFocusRingRects(Vector<IntRect>& rects, const LayoutPoint& additionalOffset, const RenderLayerModelObject* paintContainer)
{
    if (!isSpatialNavigationEnabled(frame()))
        return RenderBlockFlow::addFocusRingRects(rects, additionalOffset, paintContainer);

    HTMLSelectElement* select = selectElement();

    // Focus the last selected item.
    int selectedItem = select->activeSelectionEndListIndex();
    if (selectedItem >= 0) {
        rects.append(pixelSnappedIntRect(itemBoundingBoxRect(additionalOffset, selectedItem)));
        return;
    }

    // No selected items, find the first non-disabled item.
    int size = numItems();
    const Vector<HTMLElement*>& listItems = select->listItems();
    for (int i = 0; i < size; ++i) {
        HTMLElement* element = listItems[i];
        if (isHTMLOptionElement(*element) && !element->isDisabledFormControl()) {
            rects.append(pixelSnappedIntRect(itemBoundingBoxRect(additionalOffset, i)));
            return;
        }
    }
}

int RenderListBox::scrollbarLeft() const
{
    int scrollbarLeft = 0;
    if (style()->shouldPlaceBlockDirectionScrollbarOnLogicalLeft())
        scrollbarLeft = borderLeft();
    else
        scrollbarLeft = width() - borderRight() - verticalScrollbarWidth();
    return scrollbarLeft;
}

void RenderListBox::paintScrollbar(PaintInfo& paintInfo, const LayoutPoint& paintOffset)
{
    if (m_vBar) {
        IntRect scrollRect = pixelSnappedIntRect(paintOffset.x() + scrollbarLeft(),
            paintOffset.y() + borderTop(),
            verticalScrollbarWidth(),
            height() - (borderTop() + borderBottom()));
        m_vBar->setFrameRect(scrollRect);
        m_vBar->paint(paintInfo.context, paintInfo.rect);
    }
}

static LayoutSize itemOffsetForAlignment(TextRun textRun, RenderStyle* itemStyle, Font itemFont, LayoutRect itemBoudingBox)
{
    ETextAlign actualAlignment = itemStyle->textAlign();
    // FIXME: Firefox doesn't respect JUSTIFY. Should we?
    // FIXME: Handle TAEND here
    if (actualAlignment == TASTART || actualAlignment == JUSTIFY)
      actualAlignment = itemStyle->isLeftToRightDirection() ? LEFT : RIGHT;

    LayoutSize offset = LayoutSize(0, itemFont.fontMetrics().ascent());
    if (actualAlignment == RIGHT || actualAlignment == WEBKIT_RIGHT) {
        float textWidth = itemFont.width(textRun);
        offset.setWidth(itemBoudingBox.width() - textWidth - optionsSpacingHorizontal);
    } else if (actualAlignment == CENTER || actualAlignment == WEBKIT_CENTER) {
        float textWidth = itemFont.width(textRun);
        offset.setWidth((itemBoudingBox.width() - textWidth) / 2);
    } else
        offset.setWidth(optionsSpacingHorizontal);
    return offset;
}

void RenderListBox::paintItemForeground(PaintInfo& paintInfo, const LayoutPoint& paintOffset, int listIndex)
{
    FontCachePurgePreventer fontCachePurgePreventer;

    HTMLSelectElement* select = selectElement();

    const Vector<HTMLElement*>& listItems = select->listItems();
    HTMLElement* element = listItems[listIndex];

    RenderStyle* itemStyle = element->renderStyle();
    if (!itemStyle)
        itemStyle = style();

    if (itemStyle->visibility() == HIDDEN)
        return;

    String itemText;
    bool isOptionElement = isHTMLOptionElement(*element);
    if (isOptionElement)
        itemText = toHTMLOptionElement(*element).textIndentedToRespectGroupLabel();
    else if (isHTMLOptGroupElement(*element))
        itemText = toHTMLOptGroupElement(*element).groupLabelText();
    applyTextTransform(style(), itemText, ' ');

    Color textColor = element->renderStyle() ? resolveColor(element->renderStyle(), CSSPropertyColor) : resolveColor(CSSPropertyColor);
    if (isOptionElement && ((toHTMLOptionElement(*element).selected() && select->suggestedIndex() < 0) || listIndex == select->suggestedIndex())) {
        if (frame()->selection().isFocusedAndActive() && document().focusedElement() == node())
            textColor = RenderTheme::theme().activeListBoxSelectionForegroundColor();
        // Honor the foreground color for disabled items
        else if (!element->isDisabledFormControl() && !select->isDisabledFormControl())
            textColor = RenderTheme::theme().inactiveListBoxSelectionForegroundColor();
    }

    paintInfo.context->setFillColor(textColor);

    TextRun textRun(itemText, 0, 0, TextRun::AllowTrailingExpansion, itemStyle->direction(), isOverride(itemStyle->unicodeBidi()), true, TextRun::NoRounding);
    Font itemFont = style()->font();
    LayoutRect r = itemBoundingBoxRect(paintOffset, listIndex);
    r.move(itemOffsetForAlignment(textRun, itemStyle, itemFont, r));

    if (isHTMLOptGroupElement(*element)) {
        FontDescription d = itemFont.fontDescription();
        d.setWeight(d.bolderWeight());
        itemFont = Font(d);
        itemFont.update(document().styleEngine()->fontSelector());
    }

    // Draw the item text
    TextRunPaintInfo textRunPaintInfo(textRun);
    textRunPaintInfo.bounds = r;
    paintInfo.context->drawBidiText(itemFont, textRunPaintInfo, roundedIntPoint(r.location()));
}

void RenderListBox::paintItemBackground(PaintInfo& paintInfo, const LayoutPoint& paintOffset, int listIndex)
{
    const Vector<HTMLElement*>& listItems = selectElement()->listItems();
    HTMLElement* element = listItems[listIndex];

    Color backColor;
    if (isHTMLOptionElement(*element) && ((toHTMLOptionElement(*element).selected() && selectElement()->suggestedIndex() < 0) || listIndex == selectElement()->suggestedIndex())) {
        if (frame()->selection().isFocusedAndActive() && document().focusedElement() == node())
            backColor = RenderTheme::theme().activeListBoxSelectionBackgroundColor();
        else
            backColor = RenderTheme::theme().inactiveListBoxSelectionBackgroundColor();
    } else {
        backColor = element->renderStyle() ? resolveColor(element->renderStyle(), CSSPropertyBackgroundColor) : resolveColor(CSSPropertyBackgroundColor);
    }

    // Draw the background for this list box item
    if (!element->renderStyle() || element->renderStyle()->visibility() != HIDDEN) {
        LayoutRect itemRect = itemBoundingBoxRect(paintOffset, listIndex);
        itemRect.intersect(controlClipRect(paintOffset));
        paintInfo.context->fillRect(pixelSnappedIntRect(itemRect), backColor);
    }
}

bool RenderListBox::isPointInOverflowControl(HitTestResult& result, const LayoutPoint& locationInContainer, const LayoutPoint& accumulatedOffset)
{
    if (!m_vBar || !m_vBar->shouldParticipateInHitTesting())
        return false;

    LayoutRect vertRect(accumulatedOffset.x() + scrollbarLeft(),
                        accumulatedOffset.y() + borderTop(),
                        verticalScrollbarWidth(),
                        height() - borderTop() - borderBottom());

    if (vertRect.contains(locationInContainer)) {
        result.setScrollbar(m_vBar.get());
        return true;
    }
    return false;
}

int RenderListBox::listIndexAtOffset(const LayoutSize& offset)
{
    if (!numItems())
        return -1;

    if (offset.height() < borderTop() + paddingTop() || offset.height() > height() - paddingBottom() - borderBottom())
        return -1;

    int scrollbarWidth = verticalScrollbarWidth();
    int rightScrollbarOffset = style()->shouldPlaceBlockDirectionScrollbarOnLogicalLeft() ? scrollbarWidth : 0;
    int leftScrollbarOffset = style()->shouldPlaceBlockDirectionScrollbarOnLogicalLeft() ? 0 : scrollbarWidth;
    if (offset.width() < borderLeft() + paddingLeft() + rightScrollbarOffset
        || offset.width() > width() - borderRight() - paddingRight() - leftScrollbarOffset)
        return -1;

    int newOffset = (offset.height() - borderTop() - paddingTop()) / itemHeight() + m_indexOffset;
    return newOffset < numItems() ? newOffset : -1;
}

void RenderListBox::panScroll(const IntPoint& panStartMousePosition)
{
    const int maxSpeed = 20;
    const int iconRadius = 7;
    const int speedReducer = 4;

    // FIXME: This doesn't work correctly with transforms.
    FloatPoint absOffset = localToAbsolute();

    IntPoint lastKnownMousePosition = frame()->eventHandler().lastKnownMousePosition();
    // We need to check if the last known mouse position is out of the window. When the mouse is out of the window, the position is incoherent
    static IntPoint previousMousePosition;
    if (lastKnownMousePosition.y() < 0)
        lastKnownMousePosition = previousMousePosition;
    else
        previousMousePosition = lastKnownMousePosition;

    int yDelta = lastKnownMousePosition.y() - panStartMousePosition.y();

    // If the point is too far from the center we limit the speed
    yDelta = max<int>(min<int>(yDelta, maxSpeed), -maxSpeed);

    if (abs(yDelta) < iconRadius) // at the center we let the space for the icon
        return;

    if (yDelta > 0)
        absOffset.move(0, listHeight().toFloat());
    else if (yDelta < 0)
        yDelta--;

    // Let's attenuate the speed
    yDelta /= speedReducer;

    IntPoint scrollPoint(0, 0);
    scrollPoint.setY(absOffset.y() + yDelta);
    int newOffset = scrollToward(scrollPoint);
    if (newOffset < 0)
        return;

    m_inAutoscroll = true;
    HTMLSelectElement* select = selectElement();
    select->updateListBoxSelection(!select->multiple());
    m_inAutoscroll = false;
}

int RenderListBox::scrollToward(const IntPoint& destination)
{
    // FIXME: This doesn't work correctly with transforms.
    FloatPoint absPos = localToAbsolute();
    IntSize positionOffset = roundedIntSize(destination - absPos);

    int rows = numVisibleItems();
    int offset = m_indexOffset;

    if (positionOffset.height() < borderTop() + paddingTop() && scrollToRevealElementAtListIndex(offset - 1))
        return offset - 1;

    if (positionOffset.height() > height() - paddingBottom() - borderBottom() && scrollToRevealElementAtListIndex(offset + rows))
        return offset + rows - 1;

    return listIndexAtOffset(positionOffset);
}

void RenderListBox::autoscroll(const IntPoint&)
{
    IntPoint pos = frame()->view()->windowToContents(frame()->eventHandler().lastKnownMousePosition());

    int endIndex = scrollToward(pos);
    if (selectElement()->isDisabledFormControl())
        return;

    if (endIndex >= 0) {
        HTMLSelectElement* select = selectElement();
        m_inAutoscroll = true;

        if (!select->multiple())
            select->setActiveSelectionAnchorIndex(endIndex);

        select->setActiveSelectionEndIndex(endIndex);
        select->updateListBoxSelection(!select->multiple());
        m_inAutoscroll = false;
    }
}

void RenderListBox::stopAutoscroll()
{
    if (selectElement()->isDisabledFormControl())
        return;

    selectElement()->listBoxOnChange();
}

bool RenderListBox::scrollToRevealElementAtListIndex(int index)
{
    if (index < 0 || index >= numItems() || listIndexIsVisible(index))
        return false;

    int newOffset;
    if (index < m_indexOffset)
        newOffset = index;
    else
        newOffset = index - numVisibleItems() + 1;

    scrollToOffsetWithoutAnimation(VerticalScrollbar, newOffset);

    return true;
}

bool RenderListBox::listIndexIsVisible(int index)
{
    return index >= m_indexOffset && index < m_indexOffset + numVisibleItems();
}

bool RenderListBox::scroll(ScrollDirection direction, ScrollGranularity granularity, float multiplier)
{
    return ScrollableArea::scroll(direction, granularity, multiplier);
}

int RenderListBox::scrollSize(ScrollbarOrientation orientation) const
{
    return orientation == VerticalScrollbar ? (numItems() - numVisibleItems()) : 0;
}

IntPoint RenderListBox::scrollPosition() const
{
    return IntPoint(0, m_indexOffset);
}

void RenderListBox::setScrollOffset(const IntPoint& offset)
{
    scrollTo(offset.y());
}

void RenderListBox::scrollTo(int newOffset)
{
    if (newOffset == m_indexOffset)
        return;

    m_indexOffset = newOffset;

    if (RuntimeEnabledFeatures::repaintAfterLayoutEnabled() && frameView()->isInPerformLayout())
        setShouldDoFullRepaintAfterLayout(true);
    else
        repaint();

    node()->document().enqueueScrollEventForNode(node());
}

LayoutUnit RenderListBox::itemHeight() const
{
    return style()->fontMetrics().height() + rowSpacing;
}

int RenderListBox::verticalScrollbarWidth() const
{
    return m_vBar && !m_vBar->isOverlayScrollbar() ? m_vBar->width() : 0;
}

// FIXME: We ignore padding in the vertical direction as far as these values are concerned, since that's
// how the control currently paints.
int RenderListBox::scrollWidth() const
{
    // There is no horizontal scrolling allowed.
    return pixelSnappedClientWidth();
}

int RenderListBox::scrollHeight() const
{
    return max(pixelSnappedClientHeight(), roundToInt(listHeight()));
}

int RenderListBox::scrollLeft() const
{
    return 0;
}

void RenderListBox::setScrollLeft(int)
{
}

int RenderListBox::scrollTop() const
{
    return m_indexOffset * itemHeight();
}

void RenderListBox::setScrollTop(int newTop)
{
    // Determine an index and scroll to it.
    int index = newTop / itemHeight();
    if (index < 0 || index >= numItems() || index == m_indexOffset)
        return;

    scrollToOffsetWithoutAnimation(VerticalScrollbar, index);
}

bool RenderListBox::nodeAtPoint(const HitTestRequest& request, HitTestResult& result, const HitTestLocation& locationInContainer, const LayoutPoint& accumulatedOffset, HitTestAction hitTestAction)
{
    if (!RenderBlockFlow::nodeAtPoint(request, result, locationInContainer, accumulatedOffset, hitTestAction))
        return false;
    const Vector<HTMLElement*>& listItems = selectElement()->listItems();
    int size = numItems();
    LayoutPoint adjustedLocation = accumulatedOffset + location();

    for (int i = 0; i < size; ++i) {
        if (itemBoundingBoxRect(adjustedLocation, i).contains(locationInContainer.point())) {
            if (Element* node = listItems[i]) {
                result.setInnerNode(node);
                if (!result.innerNonSharedNode())
                    result.setInnerNonSharedNode(node);
                result.setLocalPoint(locationInContainer.point() - toLayoutSize(adjustedLocation));
                break;
            }
        }
    }

    return true;
}

LayoutRect RenderListBox::controlClipRect(const LayoutPoint& additionalOffset) const
{
    LayoutRect clipRect = contentBoxRect();
    if (style()->shouldPlaceBlockDirectionScrollbarOnLogicalLeft())
        clipRect.moveBy(additionalOffset + LayoutPoint(verticalScrollbarWidth(), 0));
    else
        clipRect.moveBy(additionalOffset);
    return clipRect;
}

bool RenderListBox::isActive() const
{
    Page* page = frame()->page();
    return page && page->focusController().isActive();
}

void RenderListBox::invalidateScrollbarRect(Scrollbar* scrollbar, const IntRect& rect)
{
    IntRect scrollRect = rect;
    if (style()->shouldPlaceBlockDirectionScrollbarOnLogicalLeft())
        scrollRect.move(borderLeft(), borderTop());
    else
        scrollRect.move(width() - borderRight() - scrollbar->width(), borderTop());

    if (RuntimeEnabledFeatures::repaintAfterLayoutEnabled() && frameView()->isInPerformLayout()) {
        m_verticalBarDamage = scrollRect;
        m_hasVerticalBarDamage = true;
    } else {
        repaintRectangle(scrollRect);
    }
}

void RenderListBox::repaintScrollbarIfNeeded()
{
    if (!hasVerticalBarDamage())
        return;
    repaintRectangle(verticalBarDamage());

    resetScrollbarDamage();
}

IntRect RenderListBox::convertFromScrollbarToContainingView(const Scrollbar* scrollbar, const IntRect& scrollbarRect) const
{
    RenderView* view = this->view();
    if (!view)
        return scrollbarRect;

    IntRect rect = scrollbarRect;

    int scrollbarTop = borderTop();
    rect.move(scrollbarLeft(), scrollbarTop);

    return view->frameView()->convertFromRenderer(this, rect);
}

IntRect RenderListBox::convertFromContainingViewToScrollbar(const Scrollbar* scrollbar, const IntRect& parentRect) const
{
    RenderView* view = this->view();
    if (!view)
        return parentRect;

    IntRect rect = view->frameView()->convertToRenderer(this, parentRect);

    int scrollbarTop = borderTop();
    rect.move(-scrollbarLeft(), -scrollbarTop);
    return rect;
}

IntPoint RenderListBox::convertFromScrollbarToContainingView(const Scrollbar* scrollbar, const IntPoint& scrollbarPoint) const
{
    RenderView* view = this->view();
    if (!view)
        return scrollbarPoint;

    IntPoint point = scrollbarPoint;

    int scrollbarTop = borderTop();
    point.move(scrollbarLeft(), scrollbarTop);

    return view->frameView()->convertFromRenderer(this, point);
}

IntPoint RenderListBox::convertFromContainingViewToScrollbar(const Scrollbar* scrollbar, const IntPoint& parentPoint) const
{
    RenderView* view = this->view();
    if (!view)
        return parentPoint;

    IntPoint point = view->frameView()->convertToRenderer(this, parentPoint);

    int scrollbarTop = borderTop();
    point.move(-scrollbarLeft(), -scrollbarTop);
    return point;
}

IntSize RenderListBox::contentsSize() const
{
    return IntSize(scrollWidth(), scrollHeight());
}

int RenderListBox::visibleHeight() const
{
    return height();
}

int RenderListBox::visibleWidth() const
{
    return width();
}

IntPoint RenderListBox::lastKnownMousePosition() const
{
    RenderView* view = this->view();
    if (!view)
        return IntPoint();
    return view->frameView()->lastKnownMousePosition();
}

bool RenderListBox::shouldSuspendScrollAnimations() const
{
    RenderView* view = this->view();
    if (!view)
        return true;
    return view->frameView()->shouldSuspendScrollAnimations();
}

bool RenderListBox::scrollbarsCanBeActive() const
{
    RenderView* view = this->view();
    if (!view)
        return false;
    return view->frameView()->scrollbarsCanBeActive();
}

IntPoint RenderListBox::minimumScrollPosition() const
{
    return IntPoint();
}

IntPoint RenderListBox::maximumScrollPosition() const
{
    return IntPoint(0, std::max(numItems() - numVisibleItems(), 0));
}

bool RenderListBox::userInputScrollable(ScrollbarOrientation orientation) const
{
    return orientation == VerticalScrollbar;
}

bool RenderListBox::shouldPlaceVerticalScrollbarOnLeft() const
{
    return false;
}

int RenderListBox::lineStep(ScrollbarOrientation) const
{
    return 1;
}

int RenderListBox::pageStep(ScrollbarOrientation orientation) const
{
    return max(1, numVisibleItems() - 1);
}

float RenderListBox::pixelStep(ScrollbarOrientation) const
{
    return 1.0f / itemHeight();
}

IntRect RenderListBox::scrollableAreaBoundingBox() const
{
    return absoluteBoundingBoxRect();
}

PassRefPtr<Scrollbar> RenderListBox::createScrollbar()
{
    RefPtr<Scrollbar> widget;
    bool hasCustomScrollbarStyle = style()->hasPseudoStyle(SCROLLBAR);
    if (hasCustomScrollbarStyle)
        widget = RenderScrollbar::createCustomScrollbar(this, VerticalScrollbar, this->node());
    else {
        widget = Scrollbar::create(this, VerticalScrollbar, RenderTheme::theme().scrollbarControlSizeForPart(ListboxPart));
        didAddScrollbar(widget.get(), VerticalScrollbar);
    }
    document().view()->addChild(widget.get());
    return widget.release();
}

void RenderListBox::destroyScrollbar()
{
    if (!m_vBar)
        return;

    if (!m_vBar->isCustomScrollbar())
        ScrollableArea::willRemoveScrollbar(m_vBar.get(), VerticalScrollbar);
    m_vBar->removeFromParent();
    m_vBar->disconnectFromScrollableArea();
    m_vBar = nullptr;
}

void RenderListBox::setHasVerticalScrollbar(bool hasScrollbar)
{
    if (hasScrollbar == (m_vBar != 0))
        return;

    if (hasScrollbar)
        m_vBar = createScrollbar();
    else
        destroyScrollbar();

    if (m_vBar)
        m_vBar->styleChanged();

    // Force an update since we know the scrollbars have changed things.
    if (document().hasAnnotatedRegions())
        document().setAnnotatedRegionsDirty(true);
}

} // namespace WebCore
/* [<][>][^][v][top][bottom][index][help] */
root/Source/core/rendering/RenderListBox.cpp

DEFINITIONS
