HTMLPlugInImageElement.cpp   [plain text]

/*
 * Copyright (C) 2008, 2011, 2012 Apple Inc. All rights reserved.
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Library General Public
 * License as published by the Free Software Foundation; either
 * version 2 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Library General Public License for more details.
 *
 * You should have received a copy of the GNU Library General Public License
 * along with this library; see the file COPYING.LIB.  If not, write to
 * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
 * Boston, MA 02110-1301, USA.
 *
 */

#include "config.h"
#include "HTMLPlugInImageElement.h"

#include "Chrome.h"
#include "ChromeClient.h"
#include "Event.h"
#include "EventHandler.h"
#include "Frame.h"
#include "FrameLoader.h"
#include "FrameLoaderClient.h"
#include "FrameView.h"
#include "HTMLDivElement.h"
#include "HTMLImageLoader.h"
#include "Image.h"
#include "JSDocumentFragment.h"
#include "LocalizedStrings.h"
#include "Logging.h"
#include "MouseEvent.h"
#include "NodeList.h"
#include "NodeRenderStyle.h"
#include "NodeRenderingContext.h"
#include "Page.h"
#include "PlugInClient.h"
#include "PluginViewBase.h"
#include "RenderEmbeddedObject.h"
#include "RenderImage.h"
#include "RenderSnapshottedPlugIn.h"
#include "SchemeRegistry.h"
#include "ScriptController.h"
#include "SecurityOrigin.h"
#include "Settings.h"
#include "ShadowRoot.h"
#include "StyleResolver.h"
#include "Text.h"
#include <JavaScriptCore/APICast.h>
#include <JavaScriptCore/JSBase.h>
#include <wtf/CurrentTime.h>
#include <wtf/HashMap.h>
#include <wtf/text/StringHash.h>

namespace WebCore {

using namespace HTMLNames;

typedef Vector<RefPtr<HTMLPlugInImageElement> > HTMLPlugInImageElementList;
typedef HashMap<String, String> MimeTypeToLocalizedStringMap;

static const int sizingTinyDimensionThreshold = 40;
static const float sizingFullPageAreaRatioThreshold = 0.96;
static const float autostartSoonAfterUserGestureThreshold = 5.0;

// This delay should not exceed the snapshot delay in PluginView.cpp
static const double simulatedMouseClickTimerDelay = .75;
static const double removeSnapshotTimerDelay = 1.5;

static const String titleText(Page* page, String mimeType)
{
    DEFINE_STATIC_LOCAL(MimeTypeToLocalizedStringMap, mimeTypeToLabelTitleMap, ());
    String titleText = mimeTypeToLabelTitleMap.get(mimeType);
    if (!titleText.isEmpty())
        return titleText;

    titleText = page->chrome().client()->plugInStartLabelTitle(mimeType);
    if (titleText.isEmpty())
        titleText = snapshottedPlugInLabelTitle();
    mimeTypeToLabelTitleMap.set(mimeType, titleText);
    return titleText;
};

static const String subtitleText(Page* page, String mimeType)
{
    DEFINE_STATIC_LOCAL(MimeTypeToLocalizedStringMap, mimeTypeToLabelSubtitleMap, ());
    String subtitleText = mimeTypeToLabelSubtitleMap.get(mimeType);
    if (!subtitleText.isEmpty())
        return subtitleText;

    subtitleText = page->chrome().client()->plugInStartLabelSubtitle(mimeType);
    if (subtitleText.isEmpty())
        subtitleText = snapshottedPlugInLabelSubtitle();
    mimeTypeToLabelSubtitleMap.set(mimeType, subtitleText);
    return subtitleText;
};

HTMLPlugInImageElement::HTMLPlugInImageElement(const QualifiedName& tagName, Document* document, bool createdByParser, PreferPlugInsForImagesOption preferPlugInsForImagesOption)
    : HTMLPlugInElement(tagName, document)
    // m_needsWidgetUpdate(!createdByParser) allows HTMLObjectElement to delay
    // widget updates until after all children are parsed.  For HTMLEmbedElement
    // this delay is unnecessary, but it is simpler to make both classes share
    // the same codepath in this class.
    , m_needsWidgetUpdate(!createdByParser)
    , m_shouldPreferPlugInsForImages(preferPlugInsForImagesOption == ShouldPreferPlugInsForImages)
    , m_needsDocumentActivationCallbacks(false)
    , m_simulatedMouseClickTimer(this, &HTMLPlugInImageElement::simulatedMouseClickTimerFired, simulatedMouseClickTimerDelay)
    , m_swapRendererTimer(this, &HTMLPlugInImageElement::swapRendererTimerFired)
    , m_removeSnapshotTimer(this, &HTMLPlugInImageElement::removeSnapshotTimerFired)
    , m_createdDuringUserGesture(ScriptController::processingUserGesture())
    , m_isRestartedPlugin(false)
    , m_needsCheckForSizeChange(false)
    , m_plugInWasCreated(false)
    , m_deferredPromotionToPrimaryPlugIn(false)
    , m_snapshotDecision(SnapshotNotYetDecided)
{
    setHasCustomStyleCallbacks();
}

HTMLPlugInImageElement::~HTMLPlugInImageElement()
{
    if (m_needsDocumentActivationCallbacks)
        document()->unregisterForPageCacheSuspensionCallbacks(this);
}

void HTMLPlugInImageElement::setDisplayState(DisplayState state)
{
#if PLATFORM(MAC)
    if (state == RestartingWithPendingMouseClick || state == Restarting) {
        m_isRestartedPlugin = true;
        m_snapshotDecision = NeverSnapshot;
        setNeedsStyleRecalc(SyntheticStyleChange);
        if (displayState() == DisplayingSnapshot)
            m_removeSnapshotTimer.startOneShot(removeSnapshotTimerDelay);
    }
#endif

    HTMLPlugInElement::setDisplayState(state);

    if (state == DisplayingSnapshot)
        m_swapRendererTimer.startOneShot(0);
}

RenderEmbeddedObject* HTMLPlugInImageElement::renderEmbeddedObject() const
{
    // HTMLObjectElement and HTMLEmbedElement may return arbitrary renderers
    // when using fallback content.
    if (!renderer() || !renderer()->isEmbeddedObject())
        return 0;
    return toRenderEmbeddedObject(renderer());
}

bool HTMLPlugInImageElement::isImageType()
{
    if (m_serviceType.isEmpty() && protocolIs(m_url, "data"))
        m_serviceType = mimeTypeFromDataURL(m_url);

    if (Frame* frame = document()->frame()) {
        KURL completedURL = document()->completeURL(m_url);
        return frame->loader()->client()->objectContentType(completedURL, m_serviceType, shouldPreferPlugInsForImages()) == ObjectContentImage;
    }

    return Image::supportsType(m_serviceType);
}

// We don't use m_url, as it may not be the final URL that the object loads,
// depending on <param> values.
bool HTMLPlugInImageElement::allowedToLoadFrameURL(const String& url)
{
    KURL completeURL = document()->completeURL(url);

    if (contentFrame() && protocolIsJavaScript(completeURL)
        && !document()->securityOrigin()->canAccess(contentDocument()->securityOrigin()))
        return false;

    return document()->frame()->isURLAllowed(completeURL);
}

// We don't use m_url, or m_serviceType as they may not be the final values
// that <object> uses depending on <param> values.
bool HTMLPlugInImageElement::wouldLoadAsNetscapePlugin(const String& url, const String& serviceType)
{
    ASSERT(document());
    ASSERT(document()->frame());
    KURL completedURL;
    if (!url.isEmpty())
        completedURL = document()->completeURL(url);

    FrameLoader* frameLoader = document()->frame()->loader();
    ASSERT(frameLoader);
    if (frameLoader->client()->objectContentType(completedURL, serviceType, shouldPreferPlugInsForImages()) == ObjectContentNetscapePlugin)
        return true;
    return false;
}

RenderObject* HTMLPlugInImageElement::createRenderer(RenderArena* arena, RenderStyle* style)
{
    // Once a PlugIn Element creates its renderer, it needs to be told when the Document goes
    // inactive or reactivates so it can clear the renderer before going into the page cache.
    if (!m_needsDocumentActivationCallbacks) {
        m_needsDocumentActivationCallbacks = true;
        document()->registerForPageCacheSuspensionCallbacks(this);
    }

    if (displayState() == DisplayingSnapshot) {
        RenderSnapshottedPlugIn* renderSnapshottedPlugIn = new (arena) RenderSnapshottedPlugIn(this);
        renderSnapshottedPlugIn->updateSnapshot(m_snapshotImage);
        return renderSnapshottedPlugIn;
    }

    // Fallback content breaks the DOM->Renderer class relationship of this
    // class and all superclasses because createObject won't necessarily
    // return a RenderEmbeddedObject, RenderPart or even RenderWidget.
    if (useFallbackContent())
        return RenderObject::createObject(this, style);

    if (isImageType()) {
        RenderImage* image = new (arena) RenderImage(this);
        image->setImageResource(RenderImageResource::create());
        return image;
    }

    return new (arena) RenderEmbeddedObject(this);
}

bool HTMLPlugInImageElement::willRecalcStyle(StyleChange)
{
    // FIXME: Why is this necessary?  Manual re-attach is almost always wrong.
    if (!useFallbackContent() && needsWidgetUpdate() && renderer() && !isImageType() && (displayState() != DisplayingSnapshot))
        reattach();
    return true;
}

void HTMLPlugInImageElement::attach(const AttachContext& context)
{
    PostAttachCallbackDisabler disabler(this);

    bool isImage = isImageType();

    if (!isImage)
        queuePostAttachCallback(&HTMLPlugInImageElement::updateWidgetCallback, this);

    HTMLPlugInElement::attach(context);

    if (isImage && renderer() && !useFallbackContent()) {
        if (!m_imageLoader)
            m_imageLoader = adoptPtr(new HTMLImageLoader(this));
        m_imageLoader->updateFromElement();
    }
}

void HTMLPlugInImageElement::detach(const AttachContext& context)
{
    // FIXME: Because of the insanity that is HTMLPlugInImageElement::recalcStyle,
    // we can end up detaching during an attach() call, before we even have a
    // renderer.  In that case, don't mark the widget for update.
    if (attached() && renderer() && !useFallbackContent())
        // Update the widget the next time we attach (detaching destroys the plugin).
        setNeedsWidgetUpdate(true);
    HTMLPlugInElement::detach(context);
}

void HTMLPlugInImageElement::updateWidgetIfNecessary()
{
    document()->updateStyleIfNeeded();

    if (!needsWidgetUpdate() || useFallbackContent() || isImageType())
        return;

    if (!renderEmbeddedObject() || renderEmbeddedObject()->isPluginUnavailable())
        return;

    updateWidget(CreateOnlyNonNetscapePlugins);
}

void HTMLPlugInImageElement::finishParsingChildren()
{
    HTMLPlugInElement::finishParsingChildren();
    if (useFallbackContent())
        return;

    setNeedsWidgetUpdate(true);
    if (inDocument())
        setNeedsStyleRecalc();
}

void HTMLPlugInImageElement::didMoveToNewDocument(Document* oldDocument)
{
    if (m_needsDocumentActivationCallbacks) {
        if (oldDocument)
            oldDocument->unregisterForPageCacheSuspensionCallbacks(this);
        document()->registerForPageCacheSuspensionCallbacks(this);
    }

    if (m_imageLoader)
        m_imageLoader->elementDidMoveToNewDocument();
    HTMLPlugInElement::didMoveToNewDocument(oldDocument);
}

void HTMLPlugInImageElement::documentWillSuspendForPageCache()
{
    if (RenderStyle* renderStyle = this->renderStyle()) {
        m_customStyleForPageCache = RenderStyle::clone(renderStyle);
        m_customStyleForPageCache->setDisplay(NONE);
        recalcStyle(Force);
    }

    HTMLPlugInElement::documentWillSuspendForPageCache();
}

void HTMLPlugInImageElement::documentDidResumeFromPageCache()
{
    if (m_customStyleForPageCache) {
        m_customStyleForPageCache = 0;
        recalcStyle(Force);
    }

    HTMLPlugInElement::documentDidResumeFromPageCache();
}

PassRefPtr<RenderStyle> HTMLPlugInImageElement::customStyleForRenderer()
{
    if (!m_customStyleForPageCache)
        return document()->ensureStyleResolver()->styleForElement(this);
    return m_customStyleForPageCache;
}

void HTMLPlugInImageElement::updateWidgetCallback(Node* n, unsigned)
{
    static_cast<HTMLPlugInImageElement*>(n)->updateWidgetIfNecessary();
}

void HTMLPlugInImageElement::updateSnapshot(PassRefPtr<Image> image)
{
    if (displayState() > DisplayingSnapshot)
        return;

    m_snapshotImage = image;

    if (renderer()->isSnapshottedPlugIn()) {
        toRenderSnapshottedPlugIn(renderer())->updateSnapshot(image);
        return;
    }

    if (renderer()->isEmbeddedObject())
        renderer()->repaint();
}

void HTMLPlugInImageElement::checkSnapshotStatus()
{
    if (!renderer()->isSnapshottedPlugIn()) {
        if (displayState() == Playing)
            checkSizeChangeForSnapshotting();
        return;
    }

    // Notify the shadow root that the size changed so that we may update the overlay layout.
    ensureUserAgentShadowRoot()->dispatchEvent(Event::create(eventNames().resizeEvent, true, false));
}

void HTMLPlugInImageElement::didAddUserAgentShadowRoot(ShadowRoot* root)
{
    Page* page = document()->page();
    if (!page)
        return;

    // Reset any author styles that may apply as we only want explicit
    // styles defined in the injected user agents stylesheets to specify
    // the look-and-feel of the snapshotted plug-in overlay. 
    root->setResetStyleInheritance(true);
    
    String mimeType = loadedMimeType();

    DEFINE_STATIC_LOCAL(RefPtr<DOMWrapperWorld>, isolatedWorld, (DOMWrapperWorld::create(JSDOMWindow::commonVM())));
    document()->ensurePlugInsInjectedScript(isolatedWorld.get());

    ScriptController* scriptController = page->mainFrame()->script();
    JSDOMGlobalObject* globalObject = JSC::jsCast<JSDOMGlobalObject*>(scriptController->globalObject(isolatedWorld.get()));
    JSC::ExecState* exec = globalObject->globalExec();

    JSC::JSLockHolder lock(exec);

    JSC::MarkedArgumentBuffer argList;
    argList.append(toJS(exec, globalObject, root));
    argList.append(jsString(exec, titleText(page, mimeType)));
    argList.append(jsString(exec, subtitleText(page, mimeType)));
    
    // This parameter determines whether or not the snapshot overlay should always be visible over the plugin snapshot.
    // If no snapshot was found then we want the overlay to be visible.
    argList.append(JSC::jsBoolean(!m_snapshotImage));

    // It is expected the JS file provides a createOverlay(shadowRoot, title, subtitle) function.
    JSC::JSObject* overlay = globalObject->get(exec, JSC::Identifier(exec, "createOverlay")).toObject(exec);
    JSC::CallData callData;
    JSC::CallType callType = overlay->methodTable()->getCallData(overlay, callData);
    if (callType == JSC::CallTypeNone)
        return;

    JSC::JSObject* thisObj = globalObject->methodTable()->toThisObject(globalObject, exec);

    JSC::call(exec, overlay, callType, callData, thisObj, argList);
}

bool HTMLPlugInImageElement::partOfSnapshotOverlay(Node* node)
{
    DEFINE_STATIC_LOCAL(AtomicString, selector, (".snapshot-overlay", AtomicString::ConstructFromLiteral));
    RefPtr<Element> snapshotLabel = ensureUserAgentShadowRoot()->querySelector(selector, ASSERT_NO_EXCEPTION);
    return node && snapshotLabel && (node == snapshotLabel.get() || node->isDescendantOf(snapshotLabel.get()));
}

void HTMLPlugInImageElement::swapRendererTimerFired(Timer<HTMLPlugInImageElement>*)
{
    ASSERT(displayState() == DisplayingSnapshot);
    if (userAgentShadowRoot())
        return;

    // Create a shadow root, which will trigger the code to add a snapshot container
    // and reattach, thus making a new Renderer.
    ensureUserAgentShadowRoot();
}

void HTMLPlugInImageElement::removeSnapshotTimerFired(Timer<HTMLPlugInImageElement>*)
{
    m_snapshotImage = nullptr;
    m_isRestartedPlugin = false;
    setNeedsStyleRecalc(SyntheticStyleChange);
    if (renderer())
        renderer()->repaint();
}

static void addPlugInsFromNodeListMatchingPlugInOrigin(HTMLPlugInImageElementList& plugInList, PassRefPtr<NodeList> collection, const String& plugInOrigin, const String& mimeType)
{
    for (unsigned i = 0, length = collection->length(); i < length; i++) {
        Node* node = collection->item(i);
        if (node->isPluginElement()) {
            HTMLPlugInElement* plugInElement = toHTMLPlugInElement(node);
            if (plugInElement->isPlugInImageElement()) {
                HTMLPlugInImageElement* plugInImageElement = toHTMLPlugInImageElement(node);
                const KURL& loadedURL = plugInImageElement->loadedUrl();
                String otherMimeType = plugInImageElement->loadedMimeType();
                if (plugInOrigin == loadedURL.host() && mimeType == otherMimeType)
                    plugInList.append(plugInImageElement);
            }
        }
    }
}

void HTMLPlugInImageElement::restartSimilarPlugIns()
{
    // Restart any other snapshotted plugins in the page with the same origin. Note that they
    // may be in different frames, so traverse from the top of the document.

    String plugInOrigin = m_loadedUrl.host();
    String mimeType = loadedMimeType();
    HTMLPlugInImageElementList similarPlugins;

    if (!document()->page())
        return;

    for (Frame* frame = document()->page()->mainFrame(); frame; frame = frame->tree()->traverseNext()) {
        if (!frame->loader()->subframeLoader()->containsPlugins())
            continue;
        
        if (!frame->document())
            continue;

        RefPtr<NodeList> plugIns = frame->document()->getElementsByTagName(embedTag.localName());
        if (plugIns)
            addPlugInsFromNodeListMatchingPlugInOrigin(similarPlugins, plugIns, plugInOrigin, mimeType);

        plugIns = frame->document()->getElementsByTagName(objectTag.localName());
        if (plugIns)
            addPlugInsFromNodeListMatchingPlugInOrigin(similarPlugins, plugIns, plugInOrigin, mimeType);
    }

    for (size_t i = 0, length = similarPlugins.size(); i < length; ++i) {
        HTMLPlugInImageElement* plugInToRestart = similarPlugins[i].get();
        if (plugInToRestart->displayState() <= HTMLPlugInElement::DisplayingSnapshot) {
            LOG(Plugins, "%p Plug-in looks similar to a restarted plug-in. Restart.", plugInToRestart);
            plugInToRestart->restartSnapshottedPlugIn();
        }
        plugInToRestart->m_snapshotDecision = NeverSnapshot;
    }
}

void HTMLPlugInImageElement::userDidClickSnapshot(PassRefPtr<MouseEvent> event, bool forwardEvent)
{
    if (forwardEvent)
        m_pendingClickEventFromSnapshot = event;

    String plugInOrigin = m_loadedUrl.host();
    if (document()->page() && !SchemeRegistry::shouldTreatURLSchemeAsLocal(document()->page()->mainFrame()->document()->baseURL().protocol()) && document()->page()->settings()->autostartOriginPlugInSnapshottingEnabled())
        document()->page()->plugInClient()->didStartFromOrigin(document()->page()->mainFrame()->document()->baseURL().host(), plugInOrigin, loadedMimeType());

    LOG(Plugins, "%p User clicked on snapshotted plug-in. Restart.", this);
    restartSnapshottedPlugIn();
    if (forwardEvent)
        setDisplayState(HTMLPlugInElement::RestartingWithPendingMouseClick);
    restartSimilarPlugIns();
}

void HTMLPlugInImageElement::setIsPrimarySnapshottedPlugIn(bool isPrimarySnapshottedPlugIn)
{
    if (!document()->page() || !document()->page()->settings()->primaryPlugInSnapshotDetectionEnabled() || document()->page()->settings()->snapshotAllPlugIns())
        return;

    if (isPrimarySnapshottedPlugIn) {
        if (m_plugInWasCreated) {
            LOG(Plugins, "%p Plug-in was detected as the primary element in the page. Restart.", this);
            restartSnapshottedPlugIn();
            restartSimilarPlugIns();
        } else {
            LOG(Plugins, "%p Plug-in was detected as the primary element in the page, but is not yet created. Will restart later.", this);
            m_deferredPromotionToPrimaryPlugIn = true;
        }
    }
}

void HTMLPlugInImageElement::restartSnapshottedPlugIn()
{
    if (displayState() >= RestartingWithPendingMouseClick)
        return;

    setDisplayState(Restarting);
    reattach();
}

void HTMLPlugInImageElement::dispatchPendingMouseClick()
{
    ASSERT(!m_simulatedMouseClickTimer.isActive());
    m_simulatedMouseClickTimer.restart();
}

void HTMLPlugInImageElement::simulatedMouseClickTimerFired(DeferrableOneShotTimer<HTMLPlugInImageElement>*)
{
    ASSERT(displayState() == RestartingWithPendingMouseClick);
    ASSERT(m_pendingClickEventFromSnapshot);

    setDisplayState(Playing);
    dispatchSimulatedClick(m_pendingClickEventFromSnapshot.get(), SendMouseOverUpDownEvents, DoNotShowPressedLook);

    m_pendingClickEventFromSnapshot = nullptr;
}

static bool documentHadRecentUserGesture(Document* document)
{
    double lastKnownUserGestureTimestamp = document->lastHandledUserGestureTimestamp();

    if (document->frame() != document->page()->mainFrame() && document->page()->mainFrame() && document->page()->mainFrame()->document())
        lastKnownUserGestureTimestamp = std::max(lastKnownUserGestureTimestamp, document->page()->mainFrame()->document()->lastHandledUserGestureTimestamp());

    if (currentTime() - lastKnownUserGestureTimestamp < autostartSoonAfterUserGestureThreshold)
        return true;

    return false;
}

void HTMLPlugInImageElement::checkSizeChangeForSnapshotting()
{
    if (!m_needsCheckForSizeChange || m_snapshotDecision != MaySnapshotWhenResized || documentHadRecentUserGesture(document()))
        return;

    m_needsCheckForSizeChange = false;
    LayoutRect contentBoxRect = toRenderBox(renderer())->contentBoxRect();
    int contentWidth = contentBoxRect.width();
    int contentHeight = contentBoxRect.height();

    if (contentWidth <= sizingTinyDimensionThreshold || contentHeight <= sizingTinyDimensionThreshold)
        return;

    LOG(Plugins, "%p Plug-in originally avoided snapshotting because it was sized %dx%d. Now it is %dx%d. Tell it to snapshot.\n", this, m_sizeWhenSnapshotted.width(), m_sizeWhenSnapshotted.height(), contentWidth, contentHeight);
    setDisplayState(WaitingForSnapshot);
    m_snapshotDecision = Snapshotted;
    Widget* widget = pluginWidget();
    if (widget && widget->isPluginViewBase())
        toPluginViewBase(widget)->beginSnapshottingRunningPlugin();
}

void HTMLPlugInImageElement::subframeLoaderWillCreatePlugIn(const KURL& url)
{
    LOG(Plugins, "%p Plug-in URL: %s", this, m_url.utf8().data());
    LOG(Plugins, "   Actual URL: %s", url.string().utf8().data());
    LOG(Plugins, "   MIME type: %s", loadedMimeType().utf8().data());

    m_loadedUrl = url;
    m_plugInWasCreated = false;
    m_deferredPromotionToPrimaryPlugIn = false;

    if (!document()->page() || !document()->page()->settings()->plugInSnapshottingEnabled()) {
        m_snapshotDecision = NeverSnapshot;
        return;
    }

    if (displayState() == Restarting) {
        LOG(Plugins, "%p Plug-in is explicitly restarting", this);
        m_snapshotDecision = NeverSnapshot;
        setDisplayState(Playing);
        return;
    }

    if (displayState() == RestartingWithPendingMouseClick) {
        LOG(Plugins, "%p Plug-in is explicitly restarting but also waiting for a click", this);
        m_snapshotDecision = NeverSnapshot;
        return;
    }

    if (m_snapshotDecision == NeverSnapshot) {
        LOG(Plugins, "%p Plug-in is blessed, allow it to start", this);
        return;
    }

    bool inMainFrame = document()->frame() == document()->page()->mainFrame();

    if (document()->isPluginDocument() && inMainFrame) {
        LOG(Plugins, "%p Plug-in document in main frame", this);
        m_snapshotDecision = NeverSnapshot;
        return;
    }

    if (ScriptController::processingUserGesture()) {
        LOG(Plugins, "%p Script is currently processing user gesture, set to play", this);
        m_snapshotDecision = NeverSnapshot;
        return;
    }

    if (m_createdDuringUserGesture) {
        LOG(Plugins, "%p Plug-in was created when processing user gesture, set to play", this);
        m_snapshotDecision = NeverSnapshot;
        return;
    }

    if (documentHadRecentUserGesture(document())) {
        LOG(Plugins, "%p Plug-in was created shortly after a user gesture, set to play", this);
        m_snapshotDecision = NeverSnapshot;
        return;
    }

    if (document()->page()->settings()->snapshotAllPlugIns()) {
        LOG(Plugins, "%p Plug-in forced to snapshot by user preference", this);
        m_snapshotDecision = Snapshotted;
        setDisplayState(WaitingForSnapshot);
        return;
    }

    if (document()->page()->settings()->autostartOriginPlugInSnapshottingEnabled() && document()->page()->plugInClient() && document()->page()->plugInClient()->shouldAutoStartFromOrigin(document()->page()->mainFrame()->document()->baseURL().host(), url.host(), loadedMimeType())) {
        LOG(Plugins, "%p Plug-in from (%s, %s) is marked to auto-start, set to play", this, document()->page()->mainFrame()->document()->baseURL().host().utf8().data(), url.host().utf8().data());
        m_snapshotDecision = NeverSnapshot;
        return;
    }

    if (m_loadedUrl.isEmpty() && !loadedMimeType().isEmpty()) {
        LOG(Plugins, "%p Plug-in has no src URL but does have a valid mime type %s, set to play", this, loadedMimeType().utf8().data());
        m_snapshotDecision = MaySnapshotWhenContentIsSet;
        return;
    }

    if (!SchemeRegistry::shouldTreatURLSchemeAsLocal(m_loadedUrl.protocol()) && !m_loadedUrl.host().isEmpty() && m_loadedUrl.host() == document()->page()->mainFrame()->document()->baseURL().host()) {
        LOG(Plugins, "%p Plug-in is served from page's domain, set to play", this);
        m_snapshotDecision = NeverSnapshot;
        return;
    }

    RenderBox* renderEmbeddedObject = toRenderBox(renderer());
    Length styleWidth = renderEmbeddedObject->style()->width();
    Length styleHeight = renderEmbeddedObject->style()->height();
    LayoutRect contentBoxRect = renderEmbeddedObject->contentBoxRect();
    int contentWidth = contentBoxRect.width();
    int contentHeight = contentBoxRect.height();
    int contentArea = contentWidth * contentHeight;
    IntSize visibleViewSize = document()->frame()->view()->visibleSize();
    int visibleArea = visibleViewSize.width() * visibleViewSize.height();

    if (inMainFrame && styleWidth.isPercent() && (styleWidth.percent() == 100)
        && styleHeight.isPercent() && (styleHeight.percent() == 100)
        && (static_cast<float>(contentArea) / visibleArea > sizingFullPageAreaRatioThreshold)) {
        LOG(Plugins, "%p Plug-in is top level full page, set to play", this);
        m_snapshotDecision = NeverSnapshot;
        return;
    }

    if (contentWidth <= sizingTinyDimensionThreshold || contentHeight <= sizingTinyDimensionThreshold) {
        LOG(Plugins, "%p Plug-in is very small %dx%d, set to play", this, contentWidth, contentHeight);
        m_sizeWhenSnapshotted = IntSize(contentBoxRect.width().toInt(), contentBoxRect.height().toInt());
        m_snapshotDecision = MaySnapshotWhenResized;
        return;
    }

    if (!document()->page()->plugInClient()) {
        LOG(Plugins, "%p There is no plug-in client. Set to wait for snapshot", this);
        m_snapshotDecision = NeverSnapshot;
        setDisplayState(WaitingForSnapshot);
        return;
    }

    LOG(Plugins, "%p Plug-in from (%s, %s) is not auto-start, sized at %dx%d, set to wait for snapshot", this, document()->page()->mainFrame()->document()->baseURL().host().utf8().data(), url.host().utf8().data(), contentWidth, contentHeight);
    m_snapshotDecision = Snapshotted;
    setDisplayState(WaitingForSnapshot);
}

void HTMLPlugInImageElement::subframeLoaderDidCreatePlugIn(const Widget* widget)
{
    m_plugInWasCreated = true;

    if (widget->isPluginViewBase() && toPluginViewBase(widget)->shouldAlwaysAutoStart()) {
        LOG(Plugins, "%p Plug-in should auto-start, set to play", this);
        m_snapshotDecision = NeverSnapshot;
        setDisplayState(Playing);
        return;
    }

    if (m_deferredPromotionToPrimaryPlugIn) {
        LOG(Plugins, "%p Plug-in was created, previously deferred promotion to primary. Will promote", this);
        setIsPrimarySnapshottedPlugIn(true);
        m_deferredPromotionToPrimaryPlugIn = false;
    }
}

void HTMLPlugInImageElement::defaultEventHandler(Event* event)
{
    RenderObject* r = renderer();
    if (r && r->isEmbeddedObject()) {
        if (isPlugInImageElement() && displayState() == WaitingForSnapshot && event->isMouseEvent() && event->type() == eventNames().clickEvent) {
            MouseEvent* mouseEvent = toMouseEvent(event);
            if (mouseEvent->button() == LeftButton) {
                userDidClickSnapshot(mouseEvent, true);
                event->setDefaultHandled();
                return;
            }
        }
    }
    HTMLPlugInElement::defaultEventHandler(event);
}

} // namespace WebCore