C++ FrameLoader::history方法代码示例

bool PageCache::canCachePageContainingThisFrame(Frame* frame)
{
    for (Frame* child = frame->tree()->firstChild(); child; child = child->tree()->nextSibling()) {
        if (!canCachePageContainingThisFrame(child))
            return false;
    }
    
    FrameLoader* frameLoader = frame->loader();
    DocumentLoader* documentLoader = frameLoader->documentLoader();
    Document* document = frame->document();
    
    return documentLoader
        && documentLoader->mainDocumentError().isNull()
        // Do not cache error pages (these can be recognized as pages with substitute data or unreachable URLs).
        && !(documentLoader->substituteData().isValid() && !documentLoader->substituteData().failingURL().isEmpty())
        && (!frameLoader->subframeLoader()->containsPlugins() || frame->page()->settings()->pageCacheSupportsPlugins())
        && (!document->url().protocolIs("https") || (!documentLoader->response().cacheControlContainsNoCache() && !documentLoader->response().cacheControlContainsNoStore()))
        && (!document->domWindow() || !document->domWindow()->hasEventListeners(eventNames().unloadEvent))
#if ENABLE(SQL_DATABASE)
        && !DatabaseManager::manager().hasOpenDatabases(document)
#endif
#if ENABLE(SHARED_WORKERS)
        && !SharedWorkerRepository::hasSharedWorkers(document)
#endif
        && frameLoader->history()->currentItem()
        && !frameLoader->quickRedirectComing()
        && !documentLoader->isLoadingInAPISense()
        && !documentLoader->isStopping()
        && document->canSuspendActiveDOMObjects()
        // FIXME: We should investigating caching frames that have an associated
        // application cache. <rdar://problem/5917899> tracks that work.
        && documentLoader->applicationCacheHost()->canCacheInPageCache()
        && frameLoader->client()->canCachePage();
}

PassRefPtr<HistoryItem> HistoryController::createItemTree(Frame* targetFrame, bool clipAtTarget)
{
    RefPtr<HistoryItem> bfItem = createItem();
    saveScrollPositionAndViewStateToItem(m_previousItem.get());

    if (!clipAtTarget || m_frame != targetFrame) {
        // save frame state for items that aren't loading (khtml doesn't save those)
        saveDocumentState();

        // clipAtTarget is false for navigations within the same document, so
        // we should copy the documentSequenceNumber over to the newly create
        // item.  Non-target items are just clones, and they should therefore
        // preserve the same itemSequenceNumber.
        if (m_previousItem) {
            if (m_frame != targetFrame)
                bfItem->setItemSequenceNumber(m_previousItem->itemSequenceNumber());
            bfItem->setDocumentSequenceNumber(m_previousItem->documentSequenceNumber());
        }

        for (Frame* child = m_frame->tree()->firstChild(); child; child = child->tree()->nextSibling()) {
            // If the child is a frame corresponding to an <object> element that never loaded,
            // we don't want to create a history item, because that causes fallback content
            // to be ignored on reload.
            FrameLoader* childLoader = child->loader();
            if (childLoader->stateMachine()->startedFirstRealLoad() || !child->ownerElement()->isObjectElement())
                bfItem->addChildItem(childLoader->history()->createItemTree(targetFrame, clipAtTarget));
        }
    }
    // FIXME: Eliminate the isTargetItem flag in favor of itemSequenceNumber.
    if (m_frame == targetFrame)
        bfItem->setIsTargetItem(true);
    return bfItem;
}

void HistoryController::updateBackForwardListClippedAtTarget(bool doClip)
{
    // In the case of saving state about a page with frames, we store a tree of items that mirrors the frame tree.  
    // The item that was the target of the user's navigation is designated as the "targetItem".  
    // When this function is called with doClip=true we're able to create the whole tree except for the target's children, 
    // which will be loaded in the future. That part of the tree will be filled out as the child loads are committed.

    Page* page = m_frame->page();
    if (!page)
        return;

    if (m_frame->loader()->documentLoader()->urlForHistory().isEmpty())
        return;

    Frame* mainFrame = page->mainFrame();
    ASSERT(mainFrame);
    FrameLoader* frameLoader = mainFrame->loader();

    frameLoader->checkDidPerformFirstNavigation();

    RefPtr<HistoryItem> topItem = frameLoader->history()->createItemTree(m_frame, doClip);
    LOG(BackForward, "WebCoreBackForward - Adding backforward item %p for frame %s", topItem.get(), m_frame->loader()->documentLoader()->url().string().ascii().data());
    page->backForward()->addItem(topItem.release());
}

PassRefPtr<HistoryItem> HistoryController::createItemTree(Frame* targetFrame, bool clipAtTarget)
{
    RefPtr<HistoryItem> bfItem = createItem(m_frame->tree()->parent() ? true : false);
    if (m_previousItem)
        saveScrollPositionAndViewStateToItem(m_previousItem.get());
    if (!(clipAtTarget && m_frame == targetFrame)) {
        // save frame state for items that aren't loading (khtml doesn't save those)
        saveDocumentState();
        for (Frame* child = m_frame->tree()->firstChild(); child; child = child->tree()->nextSibling()) {
            FrameLoader* childLoader = child->loader();
            bool hasChildLoaded = childLoader->frameHasLoaded();

            // If the child is a frame corresponding to an <object> element that never loaded,
            // we don't want to create a history item, because that causes fallback content
            // to be ignored on reload.
            
            if (!(!hasChildLoaded && childLoader->isHostedByObjectElement()))
                bfItem->addChildItem(childLoader->history()->createItemTree(targetFrame, clipAtTarget));
        }
    }
    if (m_frame == targetFrame)
        bfItem->setIsTargetItem(true);
    return bfItem;
}