C++ RenderBox类代码示例

RenderObject* RenderFieldset::layoutSpecialExcludedChild(bool relayoutChildren)
{
    RenderBox* legend = findLegend();
    if (legend) {
        if (relayoutChildren)
            legend->setNeedsLayout(true);
        legend->layoutIfNeeded();

        LayoutUnit logicalLeft;
        if (style()->isLeftToRightDirection()) {
            switch (legend->style()->textAlign()) {
            case CENTER:
                logicalLeft = (logicalWidth() - logicalWidthForChild(legend)) / 2;
                break;
            case RIGHT:
                logicalLeft = logicalWidth() - borderEnd() - paddingEnd() - logicalWidthForChild(legend);
                break;
            default:
                logicalLeft = borderStart() + paddingStart() + marginStartForChild(legend);
                break;
            }
        } else {
            switch (legend->style()->textAlign()) {
            case LEFT:
                logicalLeft = borderStart() + paddingStart();
                break;
            case CENTER: {
                // Make sure that the extra pixel goes to the end side in RTL (since it went to the end side
                // in LTR).
                LayoutUnit centeredWidth = logicalWidth() - logicalWidthForChild(legend);
                logicalLeft = centeredWidth - centeredWidth / 2;
                break;
            }
            default:
                logicalLeft = logicalWidth() - borderStart() - paddingStart() - marginStartForChild(legend) - logicalWidthForChild(legend);
                break;
            }
        }

        setLogicalLeftForChild(legend, logicalLeft);

        LayoutUnit b = borderBefore();
        LayoutUnit h = logicalHeightForChild(legend);
        setLogicalTopForChild(legend, max<LayoutUnit>((b - h) / 2, 0));
        setLogicalHeight(max(b, h) + paddingBefore());
    }
    return legend;
}

LayoutUnit RenderReplaced::computeReplacedLogicalHeight() const
{
    // 10.5 Content height: the 'height' property: http://www.w3.org/TR/CSS21/visudet.html#propdef-height
    if (hasReplacedLogicalHeight())
        return computeReplacedLogicalHeightRespectingMinMaxHeight(computeReplacedLogicalHeightUsing(style()->logicalHeight()));

    RenderBox* contentRenderer = embeddedContentBox();

    // 10.6.2 Inline, replaced elements: http://www.w3.org/TR/CSS21/visudet.html#inline-replaced-height
    bool isPercentageIntrinsicSize = false;
    double intrinsicRatio = 0;
    FloatSize intrinsicSize;
    if (contentRenderer)
        contentRenderer->computeIntrinsicRatioInformation(intrinsicSize, intrinsicRatio, isPercentageIntrinsicSize);
    else
        computeIntrinsicRatioInformation(intrinsicSize, intrinsicRatio, isPercentageIntrinsicSize);

    if (intrinsicRatio && !isHorizontalWritingMode())
        intrinsicRatio = 1 / intrinsicRatio;

    bool widthIsAuto = style()->logicalWidth().isAuto();
    bool hasIntrinsicHeight = m_hasIntrinsicSize || (!isPercentageIntrinsicSize && intrinsicSize.height() > 0);

    // If 'height' and 'width' both have computed values of 'auto' and the element also has an intrinsic height, then that intrinsic height is the used value of 'height'.
    if (widthIsAuto && hasIntrinsicHeight) {
        if (m_hasIntrinsicSize)
            return computeReplacedLogicalHeightRespectingMinMaxHeight(calcAspectRatioLogicalHeight());
        return static_cast<LayoutUnit>(intrinsicSize.height() * style()->effectiveZoom());
    }

    // Otherwise, if 'height' has a computed value of 'auto', and the element has an intrinsic ratio then the used value of 'height' is:
    // (used width) / (intrinsic ratio)
    if (intrinsicRatio && !isPercentageIntrinsicSize) {
        // FIXME: Remove unnecessary rounding when layout is off ints: webkit.org/b/63656
        return computeReplacedLogicalHeightRespectingMinMaxHeight(round(availableLogicalWidth() / intrinsicRatio));
    }

    // Otherwise, if 'height' has a computed value of 'auto', and the element has an intrinsic height, then that intrinsic height is the used value of 'height'.
    if (hasIntrinsicHeight) {
        if (m_hasIntrinsicSize)
            return computeReplacedLogicalHeightRespectingMinMaxHeight(calcAspectRatioLogicalHeight());
        return static_cast<LayoutUnit>(intrinsicSize.height() * style()->effectiveZoom());
    }

    // Otherwise, if 'height' has a computed value of 'auto', but none of the conditions above are met, then the used value of 'height' must be set to the height
    // of the largest rectangle that has a 2:1 ratio, has a height not greater than 150px, and has a width not greater than the device width.
    return computeReplacedLogicalHeightRespectingMinMaxHeight(cDefaultHeight);
}

static inline LayoutUnit borderAndPaddingBeforeInWritingMode(const RenderBox& renderer, WritingMode writingMode)
{
    switch (writingMode) {
    case TopToBottomWritingMode: return renderer.borderTop() + renderer.paddingTop();
    case BottomToTopWritingMode: return renderer.borderBottom() + renderer.paddingBottom();
    case LeftToRightWritingMode: return renderer.borderLeft() + renderer.paddingLeft();
    case RightToLeftWritingMode: return renderer.borderRight() + renderer.paddingRight();
    }

    ASSERT_NOT_REACHED();
    return renderer.borderAndPaddingBefore();
}

void RenderMediaVolumeSliderContainer::layout()
{
    RenderBlock::layout();

    if (style()->display() == NONE || !nextSibling() || !nextSibling()->isBox())
        return;

    RenderBox* buttonBox = toRenderBox(nextSibling());
    int absoluteOffsetTop = buttonBox->localToAbsolute(FloatPoint(0, -size().height())).y();

    LayoutStateDisabler layoutStateDisabler(view());

    // If the slider would be rendered outside the page, it should be moved below the controls.
    if (UNLIKELY(absoluteOffsetTop < 0))
        setY(buttonBox->offsetTop() + theme()->volumeSliderOffsetFromMuteButton(buttonBox, pixelSnappedSize()).y());
}

std::unique_ptr<FloatingObject> FloatingObject::create(RenderBox& renderer)
{
    auto object = std::make_unique<FloatingObject>(renderer);
    object->setShouldPaint(!renderer.hasSelfPaintingLayer()); // If a layer exists, the float will paint itself. Otherwise someone else will.
    object->setIsDescendant(true);
    return object;
}

int RenderView::docHeight() const
{
    int h = lowestPosition();

    // FIXME: This doesn't do any margin collapsing.
    // Instead of this dh computation we should keep the result
    // when we call RenderBlock::layout.
    int dh = 0;
    for (RenderBox* c = firstChildBox(); c; c = c->nextSiblingBox())
        dh += c->height() + c->marginTop() + c->marginBottom();

    if (dh > h)
        h = dh;

    return h;
}

void RenderGrid::resolveContentBasedTrackSizingFunctionsForItems(TrackSizingDirection direction, Vector<GridTrack>& columnTracks, Vector<GridTrack>& rowTracks, size_t i, SizingFunction sizingFunction, AccumulatorGetter trackGetter, AccumulatorGrowFunction trackGrowthFunction)
{
    GridTrack& track = (direction == ForColumns) ? columnTracks[i] : rowTracks[i];
    for (RenderBox* child = firstChildBox(); child; child = child->nextSiblingBox()) {
        size_t cellIndex = resolveGridPosition(direction, child);
        if (cellIndex != i)
            continue;

        LayoutUnit contentSize = (this->*sizingFunction)(child, direction, columnTracks);
        LayoutUnit additionalBreadthSpace = contentSize - (track.*trackGetter)();
        Vector<GridTrack*> tracks;
        tracks.append(&track);
        // FIXME: We should pass different values for |tracksForGrowthAboveMaxBreadth|.
        distributeSpaceToTracks(tracks, &tracks, trackGetter, trackGrowthFunction, additionalBreadthSpace);
    }
}

void RenderTheme::updateControlStatesForRenderer(const RenderBox& box, ControlStates& controlStates) const
{
    ControlStates newStates = extractControlStatesForRenderer(box);
    controlStates.setStates(newStates.states());
    if (isFocused(box))
        controlStates.setTimeSinceControlWasFocused(box.document().page()->focusController().timeSinceFocusWasSet());
}

PassOwnPtr<GridSpan> GridResolvedPosition::resolveGridPositionsFromStyle(const RenderStyle& gridContainerStyle, const RenderBox& gridItem, GridTrackSizingDirection direction)
{
    GridPosition initialPosition = (direction == ForColumns) ? gridItem.style()->gridColumnStart() : gridItem.style()->gridRowStart();
    const GridPositionSide initialPositionSide = (direction == ForColumns) ? ColumnStartSide : RowStartSide;
    GridPosition finalPosition = (direction == ForColumns) ? gridItem.style()->gridColumnEnd() : gridItem.style()->gridRowEnd();
    const GridPositionSide finalPositionSide = (direction == ForColumns) ? ColumnEndSide : RowEndSide;

    // We must handle the placement error handling code here instead of in the StyleAdjuster because we don't want to
    // overwrite the specified values.
    if (initialPosition.isSpan() && finalPosition.isSpan())
        finalPosition.setAutoPosition();

    if (initialPosition.isNamedGridArea() && !gridContainerStyle.namedGridArea().contains(initialPosition.namedGridLine()))
        initialPosition.setAutoPosition();

    if (finalPosition.isNamedGridArea() && !gridContainerStyle.namedGridArea().contains(finalPosition.namedGridLine()))
        finalPosition.setAutoPosition();

    if (initialPosition.shouldBeResolvedAgainstOppositePosition() && finalPosition.shouldBeResolvedAgainstOppositePosition()) {
        if (gridContainerStyle.gridAutoFlow() == AutoFlowNone)
            return adoptPtr(new GridSpan(0, 0));

        // We can't get our grid positions without running the auto placement algorithm.
        return nullptr;
    }

    if (initialPosition.shouldBeResolvedAgainstOppositePosition()) {
        // Infer the position from the final position ('auto / 1' or 'span 2 / 3' case).
        GridResolvedPosition finalResolvedPosition = resolveGridPositionFromStyle(gridContainerStyle, finalPosition, finalPositionSide);
        return resolveGridPositionAgainstOppositePosition(gridContainerStyle, finalResolvedPosition, initialPosition, initialPositionSide);
    }

    if (finalPosition.shouldBeResolvedAgainstOppositePosition()) {
        // Infer our position from the initial position ('1 / auto' or '3 / span 2' case).
        GridResolvedPosition initialResolvedPosition = resolveGridPositionFromStyle(gridContainerStyle, initialPosition, initialPositionSide);
        return resolveGridPositionAgainstOppositePosition(gridContainerStyle, initialResolvedPosition, finalPosition, finalPositionSide);
    }

    GridResolvedPosition resolvedInitialPosition = resolveGridPositionFromStyle(gridContainerStyle, initialPosition, initialPositionSide);
    GridResolvedPosition resolvedFinalPosition = resolveGridPositionFromStyle(gridContainerStyle, finalPosition, finalPositionSide);

    // If 'grid-after' specifies a line at or before that specified by 'grid-before', it computes to 'span 1'.
    if (resolvedFinalPosition < resolvedInitialPosition)
        resolvedFinalPosition = resolvedInitialPosition;

    return adoptPtr(new GridSpan(resolvedInitialPosition, resolvedFinalPosition));
}

bool ContainerNode::getLowerRightCorner(FloatPoint& point) const
{
    if (!renderer())
        return false;

    RenderObject* o = renderer();
    if (!o->isInline() || o->isReplaced()) {
        RenderBox* box = toRenderBox(o);
        point = o->localToAbsolute(LayoutPoint(box->size()), UseTransforms);
        return true;
    }

    // find the last text/image child, to get a position
    while (o) {
        if (o->lastChild())
            o = o->lastChild();
        else if (o->previousSibling())
            o = o->previousSibling();
        else {
            RenderObject* prev = 0;
            while (!prev) {
                o = o->parent();
                if (!o)
                    return false;
                prev = o->previousSibling();
            }
            o = prev;
        }
        ASSERT(o);
        if (o->isText() || o->isReplaced()) {
            point = FloatPoint();
            if (o->isText()) {
                RenderText* text = toRenderText(o);
                IntRect linesBox = text->linesBoundingBox();
                if (!linesBox.maxX() && !linesBox.maxY())
                    continue;
                point.moveBy(linesBox.maxXMaxYCorner());
            } else {
                RenderBox* box = toRenderBox(o);
                point.moveBy(box->frameRect().maxXMaxYCorner());
            }
            point = o->container()->localToAbsolute(point, UseTransforms);
            return true;
        }
    }
    return true;
}

bool ShapeOutsideInfo::isEnabledFor(const RenderBox& box)
{
    ShapeValue* shapeValue = box.style()->shapeOutside();
    if (!box.isFloating() || !shapeValue)
        return false;

    switch (shapeValue->type()) {
    case ShapeValue::Shape:
        return shapeValue->shape();
    case ShapeValue::Image:
        return shapeValue->isImageValid() && checkShapeImageOrigin(box.document(), *(shapeValue->image()));
    case ShapeValue::Box:
        return true;
    }

    return false;
}

void RenderThemeSymbian::paintButtonDecorations(RenderObject* o, const RenderObject::PaintInfo& i, const IntRect& r)
{
    RenderBox* b = static_cast<RenderBox*>(o);
    int my = max(r.y(), i.rect.y());
    int mh;
    if (r.y() < i.rect.y())
        mh = max(0, r.height() - (i.rect.y() - r.y()));
    else
        mh = std::min(i.rect.height(), r.height());

    if (o->style()->hasBackground()) {
        b->paintBackgroundExtended(i.context, o->style()->backgroundColor(), o->style()->backgroundLayers(), my, mh, r.x(), r.y(), r.width(), r.height());
    }
    if (o->style()->hasBorder()) {
        b->paintBorder(i.context, r.x(), r.y(), r.width(), r.height(), o->style());
    }
}

void RenderFieldset::paintMask(PaintInfo& paintInfo, int tx, int ty)
{
    if (style()->visibility() != VISIBLE || paintInfo.phase != PaintPhaseMask)
        return;

    int w = width();
    int h = height();
    RenderBox* legend = findLegend();
    if (!legend)
        return RenderBlock::paintMask(paintInfo, tx, ty);

    int yOff = (legend->y() > 0) ? 0 : (legend->height() - borderTop()) / 2;
    h -= yOff;
    ty += yOff;

    paintMaskImages(paintInfo, tx, ty, w, h);
}

static bool isElementLargeEnoughForMainContent(const HTMLMediaElement& element)
{
    static const double elementMainContentAreaMinimum = 400 * 300;
    static const double maximumAspectRatio = 1.8; // Slightly larger than 16:9.
    static const double minimumAspectRatio = .5; // Slightly smaller than 16:9.

    // Elements which have not yet been laid out, or which are not yet in the DOM, cannot be main content.
    RenderBox* renderer = downcast<RenderBox>(element.renderer());
    if (!renderer)
        return false;

    double width = renderer->clientWidth();
    double height = renderer->clientHeight();
    double area = width * height;
    double aspectRatio = width / height;
    return area >= elementMainContentAreaMinimum && aspectRatio >= minimumAspectRatio && aspectRatio <= maximumAspectRatio;
}

bool GraphicsContext3DInternal::lockFrontBuffer(T& image, SkRect& rect)
{
    LOGWEBGL("GraphicsContext3DInternal::lockFrontBuffer()");
    MutexLocker lock(m_fboMutex);
    FBO* fbo = m_frontFBO;

    if (!fbo || !fbo->image()) {
        LOGWEBGL("-GraphicsContext3DInternal::lockFrontBuffer(), fbo = %p", fbo);
        return false;
    }

    fbo->setLocked(true);
    image = (T)(fbo->image());

    RenderObject* renderer = m_canvas->renderer();
    if (renderer && renderer->isBox()) {
        RenderBox* box = (RenderBox*)renderer;
        rect.setXYWH(box->borderLeft() + box->paddingLeft(),
                     box->borderTop() + box->paddingTop(),
                     box->contentWidth(),
                     box->contentHeight());
    }

    return true;
}