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/*
* Copyright (C) 2008-2016 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. ``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
* 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 "RectEdges.h"
#include "ScrollSnapOffsetsInfo.h"
#include "ScrollTypes.h"
#include "Scrollbar.h"
#include <wtf/Forward.h>
#include <wtf/WeakPtr.h>
namespace WTF {
class TextStream;
}
namespace WebCore {
class FloatPoint;
class GraphicsContext;
class LayoutPoint;
class LayoutSize;
class PlatformTouchEvent;
class PlatformWheelEvent;
class ScrollAnimator;
class ScrollbarsController;
class GraphicsLayer;
class TiledBacking;
enum class WheelScrollGestureState : uint8_t;
inline int offsetForOrientation(ScrollOffset offset, ScrollbarOrientation orientation)
{
switch (orientation) {
case ScrollbarOrientation::Horizontal: return offset.x();
case ScrollbarOrientation::Vertical: return offset.y();
}
ASSERT_NOT_REACHED();
return 0;
}
class ScrollableArea : public CanMakeWeakPtr<ScrollableArea> {
public:
virtual bool isScrollView() const { return false; }
virtual bool isRenderLayer() const { return false; }
virtual bool isListBox() const { return false; }
virtual bool isPDFPlugin() const { return false; }
WEBCORE_EXPORT bool scroll(ScrollDirection, ScrollGranularity, unsigned stepCount = 1);
WEBCORE_EXPORT void scrollToPositionWithAnimation(const FloatPoint&, ScrollClamping = ScrollClamping::Clamped);
WEBCORE_EXPORT void scrollToPositionWithoutAnimation(const FloatPoint&, ScrollClamping = ScrollClamping::Clamped);
WEBCORE_EXPORT void scrollToOffsetWithoutAnimation(const FloatPoint&, ScrollClamping = ScrollClamping::Clamped);
void scrollToOffsetWithoutAnimation(ScrollbarOrientation, float offset);
// Should be called when the scroll position changes externally, for example if the scroll layer position
// is updated on the scrolling thread and we need to notify the main thread.
WEBCORE_EXPORT void notifyScrollPositionChanged(const ScrollPosition&);
// Allows subclasses to handle scroll position updates themselves. If this member function
// returns true, the scrollable area won't actually update the scroll position and instead
// expect it to happen sometime in the future.
virtual bool requestScrollPositionUpdate(const ScrollPosition&, ScrollType = ScrollType::User, ScrollClamping = ScrollClamping::Clamped) { return false; }
virtual bool requestAnimatedScrollToPosition(const ScrollPosition&, ScrollClamping = ScrollClamping::Clamped) { return false; }
virtual void stopAsyncAnimatedScroll() { }
WEBCORE_EXPORT virtual bool handleWheelEventForScrolling(const PlatformWheelEvent&, std::optional<WheelScrollGestureState>);
virtual void updateSnapOffsets() { };
WEBCORE_EXPORT const LayoutScrollSnapOffsetsInfo* snapOffsetsInfo() const;
void setScrollSnapOffsetInfo(const LayoutScrollSnapOffsetsInfo&);
void clearSnapOffsets();
WEBCORE_EXPORT std::optional<unsigned> currentHorizontalSnapPointIndex() const;
WEBCORE_EXPORT std::optional<unsigned> currentVerticalSnapPointIndex() const;
WEBCORE_EXPORT void setCurrentHorizontalSnapPointIndex(std::optional<unsigned>);
WEBCORE_EXPORT void setCurrentVerticalSnapPointIndex(std::optional<unsigned>);
void resnapAfterLayout();
void doPostThumbMoveSnapping(ScrollbarOrientation);
void stopKeyboardScrollAnimation();
#if ENABLE(TOUCH_EVENTS)
virtual bool handleTouchEvent(const PlatformTouchEvent&);
#endif
#if PLATFORM(IOS_FAMILY)
virtual void didStartScroll() { }
virtual void didEndScroll() { }
virtual void didUpdateScroll() { }
#endif
// "Stepped scrolling" is used by RenderListBox; it implies that scrollbar->pixelStep() is not 1 and never has rubberbanding.
virtual bool hasSteppedScrolling() const { return false; }
ScrollClamping scrollClamping() const { return m_scrollClamping; }
void setScrollClamping(ScrollClamping clamping) { m_scrollClamping = clamping; }
void setVerticalScrollElasticity(ScrollElasticity scrollElasticity) { m_verticalScrollElasticity = scrollElasticity; }
ScrollElasticity verticalScrollElasticity() const { return m_verticalScrollElasticity; }
void setHorizontalScrollElasticity(ScrollElasticity scrollElasticity) { m_horizontalScrollElasticity = scrollElasticity; }
ScrollElasticity horizontalScrollElasticity() const { return m_horizontalScrollElasticity; }
virtual ScrollbarMode horizontalScrollbarMode() const { return ScrollbarMode::Auto; }
virtual ScrollbarMode verticalScrollbarMode() const { return ScrollbarMode::Auto; }
bool canHaveScrollbars() const { return horizontalScrollbarMode() != ScrollbarMode::AlwaysOff || verticalScrollbarMode() != ScrollbarMode::AlwaysOff; }
virtual bool horizontalScrollbarHiddenByStyle() const { return false; }
virtual bool verticalScrollbarHiddenByStyle() const { return false; }
virtual OverscrollBehavior horizontalOverscrollBehavior() const { return OverscrollBehavior::Auto; }
virtual OverscrollBehavior verticalOverscrollBehavior() const { return OverscrollBehavior::Auto; }
bool allowsHorizontalScrolling() const;
bool allowsVerticalScrolling() const;
WEBCORE_EXPORT String horizontalScrollbarStateForTesting() const;
WEBCORE_EXPORT String verticalScrollbarStateForTesting() const;
bool inLiveResize() const { return m_inLiveResize; }
WEBCORE_EXPORT virtual void willStartLiveResize();
WEBCORE_EXPORT virtual void willEndLiveResize();
WEBCORE_EXPORT void contentAreaWillPaint() const;
WEBCORE_EXPORT void mouseEnteredContentArea() const;
WEBCORE_EXPORT void mouseExitedContentArea() const;
WEBCORE_EXPORT void mouseMovedInContentArea() const;
WEBCORE_EXPORT void mouseEnteredScrollbar(Scrollbar*) const;
void mouseExitedScrollbar(Scrollbar*) const;
void mouseIsDownInScrollbar(Scrollbar*, bool) const;
void contentAreaDidShow() const;
void contentAreaDidHide() const;
void lockOverlayScrollbarStateToHidden(bool shouldLockState) const;
WEBCORE_EXPORT bool scrollbarsCanBeActive() const;
WEBCORE_EXPORT virtual void didAddScrollbar(Scrollbar*, ScrollbarOrientation);
WEBCORE_EXPORT virtual void willRemoveScrollbar(Scrollbar*, ScrollbarOrientation);
WEBCORE_EXPORT virtual void contentsResized();
// Force the contents to recompute their size (i.e. do layout).
virtual void updateContentsSize() { }
enum class AvailableSizeChangeReason {
ScrollbarsChanged,
AreaSizeChanged
};
WEBCORE_EXPORT virtual void availableContentSizeChanged(AvailableSizeChangeReason);
bool hasOverlayScrollbars() const;
WEBCORE_EXPORT virtual void setScrollbarOverlayStyle(ScrollbarOverlayStyle);
ScrollbarOverlayStyle scrollbarOverlayStyle() const { return m_scrollbarOverlayStyle; }
void invalidateScrollbars();
bool useDarkAppearanceForScrollbars() const;
virtual ScrollingNodeID scrollingNodeID() const { return 0; }
WEBCORE_EXPORT ScrollAnimator& scrollAnimator() const;
ScrollAnimator* existingScrollAnimator() const { return m_scrollAnimator.get(); }
WEBCORE_EXPORT ScrollbarsController& scrollbarsController() const;
virtual bool isActive() const = 0;
WEBCORE_EXPORT virtual void invalidateScrollbar(Scrollbar&, const IntRect&);
virtual bool isScrollCornerVisible() const = 0;
virtual IntRect scrollCornerRect() const = 0;
WEBCORE_EXPORT virtual void invalidateScrollCorner(const IntRect&);
virtual bool forceUpdateScrollbarsOnMainThreadForPerformanceTesting() const = 0;
// Convert points and rects between the scrollbar and its containing view.
// The client needs to implement these in order to be aware of layout effects
// like CSS transforms.
virtual IntRect convertFromScrollbarToContainingView(const Scrollbar& scrollbar, const IntRect& scrollbarRect) const
{
return scrollbar.Widget::convertToContainingView(scrollbarRect);
}
virtual IntRect convertFromContainingViewToScrollbar(const Scrollbar& scrollbar, const IntRect& parentRect) const
{
return scrollbar.Widget::convertFromContainingView(parentRect);
}
virtual IntPoint convertFromScrollbarToContainingView(const Scrollbar& scrollbar, const IntPoint& scrollbarPoint) const
{
return scrollbar.Widget::convertToContainingView(scrollbarPoint);
}
virtual IntPoint convertFromContainingViewToScrollbar(const Scrollbar& scrollbar, const IntPoint& parentPoint) const
{
return scrollbar.Widget::convertFromContainingView(parentPoint);
}
int horizontalScrollbarIntrusion() const;
int verticalScrollbarIntrusion() const;
WEBCORE_EXPORT IntSize scrollbarIntrusion() const;
virtual Scrollbar* horizontalScrollbar() const { return nullptr; }
virtual Scrollbar* verticalScrollbar() const { return nullptr; }
Scrollbar* scrollbarForDirection(ScrollDirection direction) const
{
switch (direction) {
case ScrollUp:
case ScrollDown:
return verticalScrollbar();
case ScrollLeft:
case ScrollRight:
return horizontalScrollbar();
}
return nullptr;
}
const IntPoint& scrollOrigin() const { return m_scrollOrigin; }
bool scrollOriginChanged() const { return m_scrollOriginChanged; }
virtual ScrollPosition scrollPosition() const = 0;
virtual ScrollPosition minimumScrollPosition() const;
virtual ScrollPosition maximumScrollPosition() const;
ScrollPosition constrainedScrollPosition(const ScrollPosition& position) const
{
return position.constrainedBetween(minimumScrollPosition(), maximumScrollPosition());
}
WEBCORE_EXPORT ScrollOffset scrollOffset() const;
ScrollOffset minimumScrollOffset() const { return { }; }
ScrollOffset maximumScrollOffset() const;
WEBCORE_EXPORT ScrollPosition scrollPositionFromOffset(ScrollOffset) const;
WEBCORE_EXPORT ScrollOffset scrollOffsetFromPosition(ScrollPosition) const;
template<typename PositionType, typename SizeType>
static PositionType scrollPositionFromOffset(PositionType offset, SizeType scrollOrigin)
{
return offset - scrollOrigin;
}
template<typename PositionType, typename SizeType>
static PositionType scrollOffsetFromPosition(PositionType position, SizeType scrollOrigin)
{
return position + scrollOrigin;
}
WEBCORE_EXPORT virtual bool scrolledToTop() const;
WEBCORE_EXPORT virtual bool scrolledToBottom() const;
WEBCORE_EXPORT virtual bool scrolledToLeft() const;
WEBCORE_EXPORT virtual bool scrolledToRight() const;
ScrollType currentScrollType() const { return m_currentScrollType; }
void setCurrentScrollType(ScrollType scrollType) { m_currentScrollType = scrollType; }
// This reflects animated scrolls triggered by CSS OM View "smooth" scrolls.
ScrollAnimationStatus scrollAnimationStatus() { return m_scrollAnimationStatus; }
void setScrollAnimationStatus(ScrollAnimationStatus status) { m_scrollAnimationStatus = status; }
bool scrollShouldClearLatchedState() const { return m_scrollShouldClearLatchedState; }
void setScrollShouldClearLatchedState(bool shouldClear) { m_scrollShouldClearLatchedState = shouldClear; }
enum VisibleContentRectIncludesScrollbars { ExcludeScrollbars, IncludeScrollbars };
enum VisibleContentRectBehavior {
ContentsVisibleRect,
#if PLATFORM(IOS_FAMILY)
LegacyIOSDocumentViewRect,
LegacyIOSDocumentVisibleRect = LegacyIOSDocumentViewRect
#else
LegacyIOSDocumentVisibleRect = ContentsVisibleRect
#endif
};
WEBCORE_EXPORT IntRect visibleContentRect(VisibleContentRectBehavior = ContentsVisibleRect) const;
WEBCORE_EXPORT IntRect visibleContentRectIncludingScrollbars(VisibleContentRectBehavior = ContentsVisibleRect) const;
int visibleWidth() const { return visibleSize().width(); }
int visibleHeight() const { return visibleSize().height(); }
virtual IntSize visibleSize() const = 0;
virtual IntSize contentsSize() const = 0;
virtual IntSize overhangAmount() const { return IntSize(); }
virtual IntPoint lastKnownMousePositionInView() const { return IntPoint(); }
virtual bool isHandlingWheelEvent() const { return false; }
virtual int headerHeight() const { return 0; }
virtual int footerHeight() const { return 0; }
// The totalContentsSize() is equivalent to the contentsSize() plus the header and footer heights.
WEBCORE_EXPORT IntSize totalContentsSize() const;
WEBCORE_EXPORT virtual IntSize reachableTotalContentsSize() const;
virtual bool useDarkAppearance() const { return false; }
virtual bool shouldSuspendScrollAnimations() const { return true; }
WEBCORE_EXPORT virtual void scrollbarStyleChanged(ScrollbarStyle /*newStyle*/, bool /*forceUpdate*/);
virtual void setVisibleScrollerThumbRect(const IntRect&) { }
// Note that this only returns scrollable areas that can actually be scrolled.
virtual ScrollableArea* enclosingScrollableArea() const = 0;
virtual bool isScrollableOrRubberbandable() = 0;
virtual bool hasScrollableOrRubberbandableAncestor() = 0;
// Returns the bounding box of this scrollable area, in the coordinate system of the enclosing scroll view.
virtual IntRect scrollableAreaBoundingBox(bool* = nullptr) const = 0;
virtual bool isUserScrollInProgress() const { return false; }
virtual bool isRubberBandInProgress() const { return false; }
virtual bool isScrollSnapInProgress() const { return false; }
virtual bool scrollAnimatorEnabled() const { return false; }
// NOTE: Only called from Internals for testing.
WEBCORE_EXPORT void setScrollOffsetFromInternals(const ScrollOffset&);
WEBCORE_EXPORT static LayoutPoint constrainScrollPositionForOverhang(const LayoutRect& visibleContentRect, const LayoutSize& totalContentsSize, const LayoutPoint& scrollPosition, const LayoutPoint& scrollOrigin, int headerHeight, int footetHeight);
LayoutPoint constrainScrollPositionForOverhang(const LayoutPoint& scrollPosition);
// Computes the double value for the scrollbar's current position and the current overhang amount.
// This function is static so that it can be called from the main thread or the scrolling thread.
WEBCORE_EXPORT static void computeScrollbarValueAndOverhang(float currentPosition, float totalSize, float visibleSize, float& doubleValue, float& overhangAmount);
static std::optional<BoxSide> targetSideForScrollDelta(FloatSize, ScrollEventAxis);
// "Pinned" means scrolled at or beyond the edge.
bool isPinnedOnSide(BoxSide) const;
WEBCORE_EXPORT RectEdges<bool> edgePinnedState() const;
// True if scrolling happens by moving compositing layers.
virtual bool usesCompositedScrolling() const { return false; }
// True if the contents can be scrolled asynchronously (i.e. by a ScrollingCoordinator).
virtual bool usesAsyncScrolling() const { return false; }
virtual GraphicsLayer* layerForHorizontalScrollbar() const { return nullptr; }
virtual GraphicsLayer* layerForVerticalScrollbar() const { return nullptr; }
bool hasLayerForHorizontalScrollbar() const;
bool hasLayerForVerticalScrollbar() const;
void verticalScrollbarLayerDidChange();
void horizontalScrollbarLayerDidChange();
virtual bool mockScrollbarsControllerEnabled() const { return false; }
virtual void logMockScrollbarsControllerMessage(const String&) const { };
virtual bool shouldPlaceVerticalScrollbarOnLeft() const = 0;
virtual String debugDescription() const = 0;
virtual float pageScaleFactor() const
{
return 1.0f;
}
virtual void didStartScrollAnimation() { }
protected:
WEBCORE_EXPORT ScrollableArea();
WEBCORE_EXPORT virtual ~ScrollableArea();
void setScrollOrigin(const IntPoint&);
void resetScrollOriginChanged() { m_scrollOriginChanged = false; }
WEBCORE_EXPORT virtual float adjustVerticalPageScrollStepForFixedContent(float step);
virtual void invalidateScrollbarRect(Scrollbar&, const IntRect&) = 0;
virtual void invalidateScrollCornerRect(const IntRect&) = 0;
friend class ScrollingCoordinator;
virtual GraphicsLayer* layerForScrollCorner() const { return nullptr; }
#if HAVE(RUBBER_BANDING)
virtual GraphicsLayer* layerForOverhangAreas() const { return nullptr; }
#endif
bool hasLayerForScrollCorner() const;
private:
WEBCORE_EXPORT virtual IntRect visibleContentRectInternal(VisibleContentRectIncludesScrollbars, VisibleContentRectBehavior) const;
void scrollPositionChanged(const ScrollPosition&);
// NOTE: Only called from the ScrollAnimator.
friend class ScrollAnimator;
void setScrollPositionFromAnimation(const ScrollPosition&);
// This function should be overridden by subclasses to perform the actual
// scroll of the content.
virtual void setScrollOffset(const ScrollOffset&) = 0;
mutable std::unique_ptr<ScrollAnimator> m_scrollAnimator;
mutable std::unique_ptr<ScrollbarsController> m_scrollbarsController;
// There are 8 possible combinations of writing mode and direction. Scroll origin will be non-zero in the x or y axis
// if there is any reversed direction or writing-mode. The combinations are:
// writing-mode / direction scrollOrigin.x() set scrollOrigin.y() set
// horizontal-tb / ltr NO NO
// horizontal-tb / rtl YES NO
// horizontal-bt / ltr NO YES
// horizontal-bt / rtl YES YES
// vertical-lr / ltr NO NO
// vertical-lr / rtl NO YES
// vertical-rl / ltr YES NO
// vertical-rl / rtl YES YES
IntPoint m_scrollOrigin;
ScrollClamping m_scrollClamping { ScrollClamping::Clamped };
ScrollElasticity m_verticalScrollElasticity { ScrollElasticity::None };
ScrollElasticity m_horizontalScrollElasticity { ScrollElasticity::None };
ScrollbarOverlayStyle m_scrollbarOverlayStyle { ScrollbarOverlayStyle::ScrollbarOverlayStyleDefault };
ScrollType m_currentScrollType { ScrollType::User };
ScrollAnimationStatus m_scrollAnimationStatus { ScrollAnimationStatus::NotAnimating };
bool m_inLiveResize { false };
bool m_scrollOriginChanged { false };
bool m_scrollShouldClearLatchedState { false };
bool m_hasActiveScrollAnimation { false };
};
WTF::TextStream& operator<<(WTF::TextStream&, const ScrollableArea&);
} // namespace WebCore