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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 "ScrollSnapOffsetsInfo.h"
#include "ScrollTypes.h"
#include "Scrollbar.h"
#include <wtf/Forward.h>
#include <wtf/WeakPtr.h>
namespace WebCore {
class FloatPoint;
class GraphicsContext;
class LayoutPoint;
class LayoutSize;
class PlatformTouchEvent;
class PlatformWheelEvent;
class ScrollAnimator;
class GraphicsLayer;
class TiledBacking;
// scrollPosition is in content coordinates (0,0 is at scrollOrigin), so may have negative components.
typedef IntPoint ScrollPosition;
// scrollOffset() is the value used by scrollbars (min is 0,0), and should never have negative components.
typedef IntPoint ScrollOffset;
inline int offsetForOrientation(ScrollOffset offset, ScrollbarOrientation orientation)
{
switch (orientation) {
case HorizontalScrollbar: return offset.x();
case VerticalScrollbar: return offset.y();
}
ASSERT_NOT_REACHED();
return 0;
}
class ScrollableArea : public CanMakeWeakPtr<ScrollableArea> {
public:
ScrollBehaviorStatus currentScrollBehaviorStatus() { return static_cast<ScrollBehaviorStatus>(m_currentScrollBehaviorStatus); }
void setScrollBehaviorStatus(ScrollBehaviorStatus status) { m_currentScrollBehaviorStatus = static_cast<unsigned>(status); }
WEBCORE_EXPORT bool scroll(ScrollDirection, ScrollGranularity, float multiplier = 1);
WEBCORE_EXPORT void scrollToOffsetWithAnimation(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; }
WEBCORE_EXPORT bool handleWheelEvent(const PlatformWheelEvent&);
#if ENABLE(CSS_SCROLL_SNAP)
WEBCORE_EXPORT const Vector<LayoutUnit>* horizontalSnapOffsets() const;
WEBCORE_EXPORT const Vector<LayoutUnit>* verticalSnapOffsets() const;
WEBCORE_EXPORT const Vector<ScrollOffsetRange<LayoutUnit>>* horizontalSnapOffsetRanges() const;
WEBCORE_EXPORT const Vector<ScrollOffsetRange<LayoutUnit>>* verticalSnapOffsetRanges() const;
virtual void updateSnapOffsets() { };
void setHorizontalSnapOffsets(const Vector<LayoutUnit>&);
void setVerticalSnapOffsets(const Vector<LayoutUnit>&);
void setHorizontalSnapOffsetRanges(const Vector<ScrollOffsetRange<LayoutUnit>>&);
void setVerticalSnapOffsetRanges(const Vector<ScrollOffsetRange<LayoutUnit>>&);
void clearHorizontalSnapOffsets();
void clearVerticalSnapOffsets();
unsigned currentHorizontalSnapPointIndex() const { return m_currentHorizontalSnapPointIndex; }
void setCurrentHorizontalSnapPointIndex(unsigned index) { m_currentHorizontalSnapPointIndex = index; }
unsigned currentVerticalSnapPointIndex() const { return m_currentVerticalSnapPointIndex; }
void setCurrentVerticalSnapPointIndex(unsigned index) { m_currentVerticalSnapPointIndex = index; }
IntPoint nearestActiveSnapPoint(const IntPoint&);
#endif
void updateScrollSnapState();
#if ENABLE(TOUCH_EVENTS)
virtual bool handleTouchEvent(const PlatformTouchEvent&);
#endif
#if PLATFORM(IOS_FAMILY)
virtual void didStartScroll() { }
virtual void didEndScroll() { }
virtual void didUpdateScroll() { }
#endif
// Functions for controlling if you can scroll past the end of the document.
bool constrainsScrollingToContentEdge() const { return m_constrainsScrollingToContentEdge; }
void setConstrainsScrollingToContentEdge(bool constrainsScrollingToContentEdge) { m_constrainsScrollingToContentEdge = constrainsScrollingToContentEdge; }
void setVerticalScrollElasticity(ScrollElasticity scrollElasticity) { m_verticalScrollElasticity = scrollElasticity; }
ScrollElasticity verticalScrollElasticity() const { return static_cast<ScrollElasticity>(m_verticalScrollElasticity); }
void setHorizontalScrollElasticity(ScrollElasticity scrollElasticity) { m_horizontalScrollElasticity = scrollElasticity; }
ScrollElasticity horizontalScrollElasticity() const { return static_cast<ScrollElasticity>(m_horizontalScrollElasticity); }
virtual ScrollbarMode horizontalScrollbarMode() const { return ScrollbarAuto; }
virtual ScrollbarMode verticalScrollbarMode() const { return ScrollbarAuto; }
bool canHaveScrollbars() const { return horizontalScrollbarMode() != ScrollbarAlwaysOff || verticalScrollbarMode() != ScrollbarAlwaysOff; }
virtual bool horizontalScrollbarHiddenByStyle() const { return false; }
virtual bool verticalScrollbarHiddenByStyle() const { return false; }
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 static_cast<ScrollbarOverlayStyle>(m_scrollbarOverlayStyle); }
bool useDarkAppearanceForScrollbars() const;
virtual ScrollingNodeID scrollingNodeID() const { return 0; }
// This getter will create a ScrollAnimator if it doesn't already exist.
WEBCORE_EXPORT ScrollAnimator& scrollAnimator() const;
// This getter will return null if the ScrollAnimator hasn't been created yet.
ScrollAnimator* existingScrollAnimator() const { return m_scrollAnimator.get(); }
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; }
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 constrainScrollPosition(const ScrollPosition& position) const
{
return position.constrainedBetween(minimumScrollPosition(), maximumScrollPosition());
}
WEBCORE_EXPORT ScrollOffset scrollOffset() const;
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 static_cast<ScrollType>(m_currentScrollType); }
void setCurrentScrollType(ScrollType scrollType) { m_currentScrollType = static_cast<unsigned>(scrollType); }
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 lastKnownMousePosition() 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 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);
// Let subclasses provide a way of asking for and servicing scroll
// animations.
virtual bool scheduleAnimation() { return false; }
void serviceScrollAnimations();
bool isHorizontalScrollerPinnedToMinimumPosition() const { return !horizontalScrollbar() || scrollOffset().x() <= 0; }
bool isHorizontalScrollerPinnedToMaximumPosition() const { return !horizontalScrollbar() || scrollOffset().x() >= maximumScrollOffset().x(); }
bool isVerticalScrollerPinnedToMinimumPosition() const { return !verticalScrollbar() || scrollOffset().y() <= 0; }
bool isVerticalScrollerPinnedToMaximumPosition() const { return !verticalScrollbar() || scrollOffset().y() >= maximumScrollOffset().y(); }
bool isPinnedInBothDirections(const IntSize&) const;
bool isPinnedHorizontallyInDirection(int horizontalScrollDelta) const;
bool isPinnedVerticallyInDirection(int verticalScrollDelta) 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 usesMockScrollAnimator() const { return false; }
virtual void logMockScrollAnimatorMessage(const String&) const { };
virtual bool shouldPlaceBlockDirectionScrollbarOnLeft() const = 0;
protected:
WEBCORE_EXPORT ScrollableArea();
WEBCORE_EXPORT virtual ~ScrollableArea();
void setScrollOrigin(const IntPoint&);
void resetScrollOriginChanged() { m_scrollOriginChanged = false; }
WEBCORE_EXPORT virtual float adjustScrollStepForFixedContent(float step, ScrollbarOrientation, ScrollGranularity);
virtual void invalidateScrollbarRect(Scrollbar&, const IntRect&) = 0;
virtual void invalidateScrollCornerRect(const IntRect&) = 0;
friend class ScrollingCoordinator;
virtual GraphicsLayer* layerForScrollCorner() const { return nullptr; }
#if ENABLE(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 setScrollOffsetFromAnimation(const ScrollOffset&);
// This function should be overridden by subclasses to perform the actual
// scroll of the content.
virtual void setScrollOffset(const ScrollOffset&) = 0;
ScrollSnapOffsetsInfo<LayoutUnit>& ensureSnapOffsetsInfo();
mutable std::unique_ptr<ScrollAnimator> m_scrollAnimator;
#if ENABLE(CSS_SCROLL_SNAP)
std::unique_ptr<ScrollSnapOffsetsInfo<LayoutUnit>> m_snapOffsetsInfo;
unsigned m_currentHorizontalSnapPointIndex { 0 };
unsigned m_currentVerticalSnapPointIndex { 0 };
#endif
// 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;
unsigned m_constrainsScrollingToContentEdge : 1;
unsigned m_inLiveResize : 1;
unsigned m_verticalScrollElasticity : 2; // ScrollElasticity
unsigned m_horizontalScrollElasticity : 2; // ScrollElasticity
unsigned m_scrollbarOverlayStyle : 2; // ScrollbarOverlayStyle
unsigned m_scrollOriginChanged : 1;
unsigned m_currentScrollType : 1; // ScrollType
unsigned m_scrollShouldClearLatchedState : 1;
unsigned m_currentScrollBehaviorStatus : 1;
};
} // namespace WebCore