/*
 * Copyright (C) 2012, 2014-2015 Apple Inc. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY APPLE INC. AND ITS CONTRIBUTORS ``AS IS''
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
 * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR ITS CONTRIBUTORS
 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
 * THE POSSIBILITY OF SUCH DAMAGE.
 */

#pragma once

#include <wtf/Platform.h>
#if PLATFORM(MAC)

#include <WebCore/ScrollbarThemeMac.h>
#include <WebCore/ScrollingStateFrameScrollingNode.h>
#include <WebCore/ScrollingTreeFrameScrollingNode.h>
#include <WebCore/ScrollingTreeScrollingNodeDelegateMac.h>
#include <wtf/RetainPtr.h>
#include <wtf/TZoneMalloc.h>

OBJC_CLASS CALayer;

namespace WebCore {

class ScrollingTreeScrollingNodeDelegateMac;

class WEBCORE_EXPORT ScrollingTreeFrameScrollingNodeMac : public ScrollingTreeFrameScrollingNode {
    WTF_MAKE_TZONE_ALLOCATED_EXPORT(ScrollingTreeFrameScrollingNodeMac, WEBCORE_EXPORT);
public:
    static Ref<ScrollingTreeFrameScrollingNode> create(ScrollingTree&, ScrollingNodeType, ScrollingNodeID);
    virtual ~ScrollingTreeFrameScrollingNodeMac();

    RetainPtr<CALayer> rootContentsLayer() const { return m_rootContentsLayer; }

    void startRubberBandSnapBack();
    void rubberBandTargetOffsetDidChange();

    bool isPointInScrollbar(const FloatPoint& pointInReferenceLayer, CALayer *referenceLayer) const;

protected:
    ScrollingTreeFrameScrollingNodeMac(ScrollingTree&, ScrollingNodeType, ScrollingNodeID);

    // ScrollingTreeNode member functions.
    bool commitStateBeforeChildren(const ScrollingStateNode&) override;
    bool commitStateAfterChildren(const ScrollingStateNode&) override;

    WheelEventHandlingResult handleWheelEvent(const PlatformWheelEvent&, EventTargeting) override;

    WEBCORE_EXPORT void repositionRelatedLayers() override;

    FloatPoint minimumScrollPosition() const override;
    FloatPoint maximumScrollPosition() const override;

    void updateMainFramePinAndRubberbandState();

    unsigned exposedUnfilledArea() const;

private:
    ScrollingTreeScrollingNodeDelegateMac& NODELETE delegate() const;

    void willBeDestroyed() final;
    void willDoProgrammaticScroll(const FloatPoint&) final;
    bool isScrollingTreeFrameScrollingNodeMac() const final { return true; };

    void currentScrollPositionChanged(ScrollType, ScrollingLayerPositionAction) final;
    void repositionScrollingLayers() final WTF_REQUIRES_LOCK(scrollingTree()->treeLock());

    RetainPtr<CALayer> m_rootContentsLayer;
    RetainPtr<CALayer> m_counterScrollingLayer;
    RetainPtr<CALayer> m_insetClipLayer;
    RetainPtr<CALayer> m_contentShadowLayer;
    RetainPtr<CALayer> m_headerLayer;
    RetainPtr<CALayer> m_footerLayer;
    
    bool m_lastScrollHadUnfilledPixels { false };
    bool m_hadFirstUpdate { false };
};

} // namespace WebCore

SPECIALIZE_TYPE_TRAITS_BEGIN(WebCore::ScrollingTreeFrameScrollingNodeMac) \
    static bool isType(const WebCore::ScrollingTreeFrameScrollingNode& node) { return node.isScrollingTreeFrameScrollingNodeMac(); } \
SPECIALIZE_TYPE_TRAITS_END()

#endif // PLATFORM(MAC)
