C++ FrameView::fixedElementsLayoutRelativeToFrame方法代码示例

void Page::setPageScaleFactor(float scale, const IntPoint& origin)
{
    Document* document = mainFrame()->document();
    FrameView* view = document->view();

    if (scale == m_pageScaleFactor) {
        if (view && (view->scrollPosition() != origin || view->delegatesScrolling())) {
            if (!m_settings->applyPageScaleFactorInCompositor())
                document->updateLayoutIgnorePendingStylesheets();
            view->setScrollPosition(origin);
        }
        return;
    }

    m_pageScaleFactor = scale;

    if (!m_settings->applyPageScaleFactorInCompositor()) {
        if (document->renderer())
            document->renderer()->setNeedsLayout(true);

        document->recalcStyle(Style::Force);

        // Transform change on RenderView doesn't trigger repaint on non-composited contents.
        mainFrame()->view()->invalidateRect(IntRect(LayoutRect::infiniteRect()));
    }

#if USE(ACCELERATED_COMPOSITING)
    mainFrame()->deviceOrPageScaleFactorChanged();
#endif

    if (view && view->fixedElementsLayoutRelativeToFrame())
        view->setViewportConstrainedObjectsNeedLayout();

    if (view && view->scrollPosition() != origin) {
        if (!m_settings->applyPageScaleFactorInCompositor() && document->renderer() && document->renderer()->needsLayout() && view->didFirstLayout())
            view->layout();
        view->setScrollPosition(origin);
    }
}

void AsyncScrollingCoordinator::frameViewLayoutUpdated(FrameView& frameView)
{
    ASSERT(isMainThread());
    ASSERT(m_page);

    // If there isn't a root node yet, don't do anything. We'll be called again after creating one.
    if (!m_scrollingStateTree->rootStateNode())
        return;

    // Compute the region of the page that we can't do fast scrolling for. This currently includes
    // all scrollable areas, such as subframes, overflow divs and list boxes. We need to do this even if the
    // frame view whose layout was updated is not the main frame.
    // In the future, we may want to have the ability to set non-fast scrolling regions for more than
    // just the root node. But right now, this concept only applies to the root.
    m_scrollingStateTree->rootStateNode()->setNonFastScrollableRegion(absoluteNonFastScrollableRegion());
    m_nonFastScrollableRegionDirty = false;

    if (!coordinatesScrollingForFrameView(frameView))
        return;

    ScrollingStateFrameScrollingNode* node = downcast<ScrollingStateFrameScrollingNode>(m_scrollingStateTree->stateNodeForID(frameView.scrollLayerID()));
    if (!node)
        return;

    Scrollbar* verticalScrollbar = frameView.verticalScrollbar();
    Scrollbar* horizontalScrollbar = frameView.horizontalScrollbar();
    node->setScrollbarPaintersFromScrollbars(verticalScrollbar, horizontalScrollbar);
    
    node->setFrameScaleFactor(frameView.frame().frameScaleFactor());
    node->setHeaderHeight(frameView.headerHeight());
    node->setFooterHeight(frameView.footerHeight());
    node->setTopContentInset(frameView.topContentInset());

    node->setScrollOrigin(frameView.scrollOrigin());
    node->setScrollableAreaSize(frameView.visibleContentRect().size());
    node->setTotalContentsSize(frameView.totalContentsSize());
    node->setReachableContentsSize(frameView.totalContentsSize());
    node->setFixedElementsLayoutRelativeToFrame(frameView.fixedElementsLayoutRelativeToFrame());

#if ENABLE(CSS_SCROLL_SNAP)
    frameView.updateSnapOffsets();
    updateScrollSnapPropertiesWithFrameView(frameView);
#endif

#if PLATFORM(COCOA)
    Page* page = frameView.frame().page();
    if (page && page->expectsWheelEventTriggers()) {
        LOG(WheelEventTestTriggers, "    AsyncScrollingCoordinator::frameViewLayoutUpdated: Expects wheel event test trigger=%d", page->expectsWheelEventTriggers());
        node->setExpectsWheelEventTestTrigger(page->expectsWheelEventTriggers());
    }
#endif

    ScrollableAreaParameters scrollParameters;
    scrollParameters.horizontalScrollElasticity = frameView.horizontalScrollElasticity();
    scrollParameters.verticalScrollElasticity = frameView.verticalScrollElasticity();
    scrollParameters.hasEnabledHorizontalScrollbar = horizontalScrollbar && horizontalScrollbar->enabled();
    scrollParameters.hasEnabledVerticalScrollbar = verticalScrollbar && verticalScrollbar->enabled();
    scrollParameters.horizontalScrollbarMode = frameView.horizontalScrollbarMode();
    scrollParameters.verticalScrollbarMode = frameView.verticalScrollbarMode();

    node->setScrollableAreaParameters(scrollParameters);
}