C++ HTMLFrameElementBase::scrollingMode方法代码示例

void RenderFrame::layout()
{
    FrameView* view = static_cast<FrameView*>(widget());
    RenderView* root = view ? view->frame()->contentRenderer() : 0;

    // Do not expand frames which has zero width or height
    if (!width() || !height() || !root) {
        updateWidgetPosition();
        if (view)
            view->layout();
        setNeedsLayout(false);
        return;
    }

    HTMLFrameElementBase* element = static_cast<HTMLFrameElementBase*>(node());
    if (element->scrollingMode() == ScrollbarAlwaysOff && !root->isFrameSet()) {
        setNeedsLayout(false);
        return;
    }

    // Update the dimensions to get the correct width and height
    updateWidgetPosition();
    if (root->preferredLogicalWidthsDirty())
        root->computePreferredLogicalWidths();

    // Expand the frame by setting frame height = content height
    setWidth(max(view->contentsWidth() + borderAndPaddingWidth(), width()));
    setHeight(max(view->contentsHeight() + borderAndPaddingHeight(), height()));

    // Update one more time
    updateWidgetPosition();

    setNeedsLayout(false);
}

Frame* SubframeLoader::loadSubframe(HTMLFrameOwnerElement* ownerElement, const KURL& url, const String& name, const String& referrer)
{
    RefPtr<Frame> protect(m_frame);

    bool allowsScrolling = true;
    int marginWidth = -1;
    int marginHeight = -1;
    if (ownerElement->hasTagName(frameTag) || ownerElement->hasTagName(iframeTag)) {
        HTMLFrameElementBase* o = static_cast<HTMLFrameElementBase*>(ownerElement);
        allowsScrolling = o->scrollingMode() != ScrollbarAlwaysOff;
        marginWidth = o->marginWidth();
        marginHeight = o->marginHeight();
    }

    if (!ownerElement->document()->securityOrigin()->canDisplay(url)) {
        FrameLoader::reportLocalLoadFailed(m_frame, url.string());
        return 0;
    }

    if (!ownerElement->document()->contentSecurityPolicy()->allowChildFrameFromSource(url))
        return 0;

    String referrerToUse = SecurityPolicy::generateReferrerHeader(ownerElement->document()->referrerPolicy(), url, referrer);
    RefPtr<Frame> frame = m_frame->loader()->client()->createFrame(url, name, ownerElement, referrerToUse, allowsScrolling, marginWidth, marginHeight);

    if (!frame)  {
        m_frame->loader()->checkCallImplicitClose();
        return 0;
    }
    
    // All new frames will have m_isComplete set to true at this point due to synchronously loading
    // an empty document in FrameLoader::init(). But many frames will now be starting an
    // asynchronous load of url, so we set m_isComplete to false and then check if the load is
    // actually completed below. (Note that we set m_isComplete to false even for synchronous
    // loads, so that checkCompleted() below won't bail early.)
    // FIXME: Can we remove this entirely? m_isComplete normally gets set to false when a load is committed.
    frame->loader()->started();
   
    RenderObject* renderer = ownerElement->renderer();
    FrameView* view = frame->view();
    if (renderer && renderer->isWidget() && view)
        toRenderWidget(renderer)->setWidget(view);
    
    m_frame->loader()->checkCallImplicitClose();
    
    // Some loads are performed synchronously (e.g., about:blank and loads
    // cancelled by returning a null ResourceRequest from requestFromDelegate).
    // In these cases, the synchronous load would have finished
    // before we could connect the signals, so make sure to send the 
    // completed() signal for the child by hand and mark the load as being
    // complete.
    // FIXME: In this case the Frame will have finished loading before 
    // it's being added to the child list. It would be a good idea to
    // create the child first, then invoke the loader separately.
    if (frame->loader()->state() == FrameStateComplete && !frame->loader()->policyDocumentLoader())
        frame->loader()->checkCompleted();

    return frame.get();
}

void RenderFrameBase::layoutWithFlattening(bool fixedWidth, bool fixedHeight)
{
    FrameView* childFrameView = static_cast<FrameView*>(widget());
    RenderView* childRoot = childFrameView ? static_cast<RenderView*>(childFrameView->frame()->contentRenderer()) : 0;

    // Do not expand frames which has zero width or height
    if (!width() || !height() || !childRoot) {
        updateWidgetPosition();
        if (childFrameView)
            childFrameView->layout();
        setNeedsLayout(false);
        return;
    }

    // need to update to calculate min/max correctly
    updateWidgetPosition();
    if (childRoot->preferredLogicalWidthsDirty())
        childRoot->computePreferredLogicalWidths();

    // if scrollbars are off, and the width or height are fixed
    // we obey them and do not expand. With frame flattening
    // no subframe much ever become scrollable.

    HTMLFrameElementBase* element = static_cast<HTMLFrameElementBase*>(node());
    bool isScrollable = element->scrollingMode() != ScrollbarAlwaysOff;

    // consider iframe inset border
    int hBorder = borderLeft() + borderRight();
    int vBorder = borderTop() + borderBottom();

    // make sure minimum preferred width is enforced
    if (isScrollable || !fixedWidth) {
        setWidth(max(width(), childRoot->minPreferredLogicalWidth() + hBorder));
        // update again to pass the new width to the child frame
        updateWidgetPosition();
        childFrameView->layout();
    }

    // expand the frame by setting frame height = content height
    if (isScrollable || !fixedHeight || childRoot->isFrameSet())
        setHeight(max(height(), childFrameView->contentsHeight() + vBorder));
    if (isScrollable || !fixedWidth || childRoot->isFrameSet())
        setWidth(max(width(), childFrameView->contentsWidth() + hBorder));

    updateWidgetPosition();

    ASSERT(!childFrameView->layoutPending());
    ASSERT(!childRoot->needsLayout());
    ASSERT(!childRoot->firstChild() || !childRoot->firstChild()->firstChild() || !childRoot->firstChild()->firstChild()->needsLayout());

    setNeedsLayout(false);
}