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/*
* Copyright (C) 2011 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.
*/
#ifndef ScrollingCoordinator_h
#define ScrollingCoordinator_h
#include "IntRect.h"
#include "LayoutRect.h"
#include "PlatformWheelEvent.h"
#include "RenderObject.h"
#include "ScrollTypes.h"
#include <wtf/Forward.h>
#if ENABLE(ASYNC_SCROLLING)
#include <wtf/HashMap.h>
#include <wtf/ThreadSafeRefCounted.h>
#include <wtf/Threading.h>
#endif
#if PLATFORM(COCOA)
#include <wtf/RetainPtr.h>
#endif
#if ENABLE(CSS_SCROLL_SNAP)
#include "AxisScrollSnapOffsets.h"
#endif
namespace WebCore {
typedef unsigned SynchronousScrollingReasons;
typedef uint64_t ScrollingNodeID;
enum ScrollingNodeType { FrameScrollingNode, OverflowScrollingNode, FixedNode, StickyNode };
class Document;
class Frame;
class FrameView;
class GraphicsLayer;
class Page;
class Region;
class ScrollableArea;
class ViewportConstraints;
#if ENABLE(ASYNC_SCROLLING)
class ScrollingTree;
#endif
enum SetOrSyncScrollingLayerPosition {
SetScrollingLayerPosition,
SyncScrollingLayerPosition
};
struct ScrollableAreaParameters {
ScrollElasticity horizontalScrollElasticity;
ScrollElasticity verticalScrollElasticity;
ScrollbarMode horizontalScrollbarMode;
ScrollbarMode verticalScrollbarMode;
bool hasEnabledHorizontalScrollbar;
bool hasEnabledVerticalScrollbar;
ScrollableAreaParameters()
: horizontalScrollElasticity(ScrollElasticityNone)
, verticalScrollElasticity(ScrollElasticityNone)
, horizontalScrollbarMode(ScrollbarAuto)
, verticalScrollbarMode(ScrollbarAuto)
, hasEnabledHorizontalScrollbar(false)
, hasEnabledVerticalScrollbar(false)
{
}
bool operator==(const ScrollableAreaParameters& other) const
{
return horizontalScrollElasticity == other.horizontalScrollElasticity
&& verticalScrollElasticity == other.verticalScrollElasticity
&& horizontalScrollbarMode == other.horizontalScrollbarMode
&& verticalScrollbarMode == other.verticalScrollbarMode
&& hasEnabledHorizontalScrollbar == other.hasEnabledHorizontalScrollbar
&& hasEnabledVerticalScrollbar == other.hasEnabledVerticalScrollbar;
}
};
class ScrollingCoordinator : public ThreadSafeRefCounted<ScrollingCoordinator> {
public:
static PassRefPtr<ScrollingCoordinator> create(Page*);
virtual ~ScrollingCoordinator();
WEBCORE_EXPORT virtual void pageDestroyed();
virtual bool isAsyncScrollingCoordinator() const { return false; }
virtual bool isRemoteScrollingCoordinator() const { return false; }
// Return whether this scrolling coordinator handles scrolling for the given frame view.
virtual bool coordinatesScrollingForFrameView(FrameView*) const;
// Should be called whenever the given frame view has been laid out.
virtual void frameViewLayoutUpdated(FrameView*) { }
// Should be called whenever a wheel event handler is added or removed in the
// frame view's underlying document.
void frameViewWheelEventHandlerCountChanged(FrameView*);
// Should be called whenever the slow repaint objects counter changes between zero and one.
void frameViewHasSlowRepaintObjectsDidChange(FrameView*);
// Should be called whenever the set of fixed objects changes.
void frameViewFixedObjectsDidChange(FrameView*);
// Called whenever the non-fast scrollable region changes for reasons other than layout.
virtual void frameViewNonFastScrollableRegionChanged(FrameView*) { }
// Should be called whenever the root layer for the given frame view changes.
virtual void frameViewRootLayerDidChange(FrameView*);
// Return whether this scrolling coordinator can keep fixed position layers fixed to their
// containers while scrolling.
virtual bool supportsFixedPositionLayers() const { return false; }
#if PLATFORM(COCOA)
// Dispatched by the scrolling tree during handleWheelEvent. This is required as long as scrollbars are painted on the main thread.
void handleWheelEventPhase(PlatformWheelEventPhase);
#endif
#if ENABLE(WEB_REPLAY)
// Called when the page transitions between executing normally and deterministically.
void replaySessionStateDidChange();
#endif
// Force all scroll layer position updates to happen on the main thread.
WEBCORE_EXPORT void setForceSynchronousScrollLayerPositionUpdates(bool);
// These virtual functions are currently unique to the threaded scrolling architecture.
// Their meaningful implementations are in ScrollingCoordinatorMac.
virtual void commitTreeStateIfNeeded() { }
virtual bool requestScrollPositionUpdate(FrameView*, const IntPoint&) { return false; }
virtual bool handleWheelEvent(FrameView*, const PlatformWheelEvent&) { return true; }
virtual ScrollingNodeID attachToStateTree(ScrollingNodeType, ScrollingNodeID newNodeID, ScrollingNodeID /*parentID*/) { return newNodeID; }
virtual void detachFromStateTree(ScrollingNodeID) { }
virtual void clearStateTree() { }
virtual void updateViewportConstrainedNode(ScrollingNodeID, const ViewportConstraints&, GraphicsLayer*) { }
struct ScrollingGeometry {
FloatSize scrollableAreaSize;
FloatSize contentSize;
FloatSize reachableContentSize; // Smaller than contentSize when overflow is hidden on one axis.
FloatPoint scrollPosition;
IntPoint scrollOrigin;
#if ENABLE(CSS_SCROLL_SNAP)
Vector<LayoutUnit> horizontalSnapOffsets;
Vector<LayoutUnit> verticalSnapOffsets;
#endif
};
virtual void updateFrameScrollingNode(ScrollingNodeID, GraphicsLayer* /*scrollLayer*/, GraphicsLayer* /*scrolledContentsLayer*/, GraphicsLayer* /*counterScrollingLayer*/, GraphicsLayer* /*insetClipLayer*/, const ScrollingGeometry* = nullptr) { }
virtual void updateOverflowScrollingNode(ScrollingNodeID, GraphicsLayer* /*scrollLayer*/, GraphicsLayer* /*scrolledContentsLayer*/, const ScrollingGeometry* = nullptr) { }
virtual void syncChildPositions(const LayoutRect&) { }
virtual String scrollingStateTreeAsText() const;
virtual bool isRubberBandInProgress() const { return false; }
virtual void setScrollPinningBehavior(ScrollPinningBehavior) { }
// Generated a unique id for scroll layers.
ScrollingNodeID uniqueScrollLayerID();
enum MainThreadScrollingReasonFlags {
ForcedOnMainThread = 1 << 0,
HasSlowRepaintObjects = 1 << 1,
HasViewportConstrainedObjectsWithoutSupportingFixedLayers = 1 << 2,
HasNonLayerViewportConstrainedObjects = 1 << 3,
IsImageDocument = 1 << 4
};
SynchronousScrollingReasons synchronousScrollingReasons(FrameView*) const;
bool shouldUpdateScrollLayerPositionSynchronously() const;
virtual void willDestroyScrollableArea(ScrollableArea*) { }
virtual void scrollableAreaScrollLayerDidChange(ScrollableArea*) { }
virtual void scrollableAreaScrollbarLayerDidChange(ScrollableArea*, ScrollbarOrientation) { }
static String synchronousScrollingReasonsAsText(SynchronousScrollingReasons);
String synchronousScrollingReasonsAsText() const;
Region computeNonFastScrollableRegion(const Frame*, const IntPoint& frameLocation) const;
protected:
explicit ScrollingCoordinator(Page*);
static GraphicsLayer* scrollLayerForScrollableArea(ScrollableArea*);
static GraphicsLayer* horizontalScrollbarLayerForScrollableArea(ScrollableArea*);
static GraphicsLayer* verticalScrollbarLayerForScrollableArea(ScrollableArea*);
unsigned computeCurrentWheelEventHandlerCount();
GraphicsLayer* scrollLayerForFrameView(FrameView*);
GraphicsLayer* counterScrollingLayerForFrameView(FrameView*);
GraphicsLayer* insetClipLayerForFrameView(FrameView*);
GraphicsLayer* rootContentLayerForFrameView(FrameView*);
GraphicsLayer* contentShadowLayerForFrameView(FrameView*);
GraphicsLayer* headerLayerForFrameView(FrameView*);
GraphicsLayer* footerLayerForFrameView(FrameView*);
Page* m_page; // FIXME: ideally this would be a reference but it gets nulled on async teardown.
private:
virtual void recomputeWheelEventHandlerCountForFrameView(FrameView*) { }
virtual void setSynchronousScrollingReasons(SynchronousScrollingReasons) { }
virtual bool hasVisibleSlowRepaintViewportConstrainedObjects(FrameView*) const;
void updateSynchronousScrollingReasons(FrameView*);
bool m_forceSynchronousScrollLayerPositionUpdates;
};
#define SCROLLING_COORDINATOR_TYPE_CASTS(ToValueTypeName, predicate) \
TYPE_CASTS_BASE(ToValueTypeName, WebCore::ScrollingCoordinator, value, value->predicate, value.predicate)
} // namespace WebCore
#endif // ScrollingCoordinator_h
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