third_party/WebKit/Source/core/dom/Fullscreen.h

/*
 * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
 *           (C) 1999 Antti Koivisto (koivisto@kde.org)
 *           (C) 2001 Dirk Mueller (mueller@kde.org)
 *           (C) 2006 Alexey Proskuryakov (ap@webkit.org)
 * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2012 Apple Inc. All rights reserved.
 * Copyright (C) 2008, 2009 Torch Mobile Inc. All rights reserved. (http://www.torchmobile.com/)
 * Copyright (C) 2010 Nokia Corporation and/or its subsidiary(-ies)
 * Copyright (C) 2013 Google 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.
 *
 */

#ifndef Fullscreen_h
#define Fullscreen_h

#include "core/CoreExport.h"
#include "core/dom/ContextLifecycleObserver.h"
#include "core/dom/Document.h"
#include "core/dom/Element.h"
#include "platform/Supplementable.h"
#include "platform/Timer.h"
#include "platform/geometry/LayoutRect.h"
#include "wtf/Deque.h"
#include "wtf/RefPtr.h"
#include "wtf/Vector.h"

namespace blink {

class LayoutFullScreen;
class ComputedStyle;

class CORE_EXPORT Fullscreen final
    : public GarbageCollectedFinalized<Fullscreen>
    , public Supplement<Document>
    , public ContextLifecycleObserver {
    USING_GARBAGE_COLLECTED_MIXIN(Fullscreen);
public:
    virtual ~Fullscreen();
    static const char* supplementName();
    static Fullscreen& from(Document&);
    static Fullscreen* fromIfExists(Document&);
    static Element* fullscreenElementFrom(Document&);
    static Element* currentFullScreenElementFrom(Document&);
    static bool isFullScreen(Document&);
    static bool isActiveFullScreenElement(const Element&);

    enum RequestType {
        // Element.requestFullscreen()
        UnprefixedRequest,
        // Element.webkitRequestFullscreen()/webkitRequestFullScreen() and
        // HTMLVideoElement.webkitEnterFullscreen()/webkitEnterFullScreen()
        PrefixedRequest,
    };

    // |forCrossProcessAncestor| is used in OOPIF scenarios and is set to true
    // when fullscreen is requested for an out-of-process descendant element.
    void requestFullscreen(Element&, RequestType, bool forCrossProcessAncestor = false);

    static void fullyExitFullscreen(Document&);
    void exitFullscreen();

    static bool fullscreenEnabled(Document&);
    Element* fullscreenElement() const { return !m_fullScreenElementStack.isEmpty() ? m_fullScreenElementStack.last().first.get() : 0; }

    // |isAncestorOfFullscreenElement| is used in OOPIF scenarios and is set to
    // true when these functions are called to enter/exit fullscreen for an
    // out-of-process descendant element.  In this case, we enter fullscreen
    // for its (local) iframe container and make sure to also set the
    // ContainsFullScreenElement flag on it (so that it gains the
    // -webkit-full-screen-ancestor style).
    void didEnterFullScreenForElement(Element*);
    void didExitFullScreenForElement();

    void setFullScreenLayoutObject(LayoutFullScreen*);
    LayoutFullScreen* fullScreenLayoutObject() const { return m_fullScreenLayoutObject; }
    void fullScreenLayoutObjectDestroyed();

    void elementRemoved(Element&);

    // Returns true if the current fullscreen element stack corresponds to a
    // container for an actual fullscreen element in an out-of-process iframe.
    bool forCrossProcessAncestor() { return m_forCrossProcessAncestor; }

    // Mozilla API
    Element* webkitCurrentFullScreenElement() const { return m_fullScreenElement.get(); }

    // ContextLifecycleObserver:
    void contextDestroyed() override;

    DECLARE_VIRTUAL_TRACE();

private:
    static Fullscreen* fromIfExistsSlow(Document&);

    explicit Fullscreen(Document&);

    Document* document();

    void clearFullscreenElementStack();
    void popFullscreenElementStack();
    void pushFullscreenElementStack(Element&, RequestType);

    void enqueueChangeEvent(Document&, RequestType);
    void enqueueErrorEvent(Element&, RequestType);
    void eventQueueTimerFired(Timer<Fullscreen>*);

    Member<Element> m_fullScreenElement;
    HeapVector<std::pair<Member<Element>, RequestType>> m_fullScreenElementStack;
    LayoutFullScreen* m_fullScreenLayoutObject;
    Timer<Fullscreen> m_eventQueueTimer;
    HeapDeque<Member<Event>> m_eventQueue;
    LayoutRect m_savedPlaceholderFrameRect;
    RefPtr<ComputedStyle> m_savedPlaceholderComputedStyle;

    // TODO(alexmos, dcheng): Currently, this assumes that if fullscreen was
    // entered for an element in an out-of-process iframe, then it's not
    // possible to re-enter fullscreen for a different element in this
    // document, since that requires a user gesture, which can't be obtained
    // since nothing in this document is visible, and since user gestures can't
    // be forwarded across processes. However, the latter assumption could
    // change if https://crbug.com/161068 is fixed so that cross-process
    // postMessage can carry user gestures.  If that happens, this should be
    // moved to be part of |m_fullScreenElementStack|.
    bool m_forCrossProcessAncestor;
};

inline bool Fullscreen::isActiveFullScreenElement(const Element& element)
{
    Fullscreen* fullscreen = fromIfExists(element.document());
    if (!fullscreen)
        return false;
    return fullscreen->webkitCurrentFullScreenElement() == &element;
}

inline Fullscreen* Fullscreen::fromIfExists(Document& document)
{
    if (!document.hasFullscreenSupplement())
        return 0;
    return fromIfExistsSlow(document);
}

} // namespace blink

#endif // Fullscreen_h