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26 #ifndef ScrollableArea_h
27 #define ScrollableArea_h
29 #include "LayoutTypes.h"
30 #include "Scrollbar.h"
31 #include <wtf/Vector.h>
36 class GraphicsContext;
37 class PlatformGestureEvent;
38 class PlatformWheelEvent;
40 #if USE(ACCELERATED_COMPOSITING)
44 class ScrollableArea {
47 virtual ~ScrollableArea();
49 bool scroll(ScrollDirection, ScrollGranularity, float multiplier = 1);
50 void scrollToOffsetWithoutAnimation(const FloatPoint&);
51 void scrollToOffsetWithoutAnimation(ScrollbarOrientation, float offset);
52 void scrollToXOffsetWithoutAnimation(float x);
53 void scrollToYOffsetWithoutAnimation(float x);
55 void handleWheelEvent(PlatformWheelEvent&);
56 #if ENABLE(GESTURE_EVENTS)
57 void handleGestureEvent(const PlatformGestureEvent&);
60 // Functions for controlling if you can scroll past the end of the document.
61 bool constrainsScrollingToContentEdge() const { return m_constrainsScrollingToContentEdge; }
62 void setConstrainsScrollingToContentEdge(bool constrainsScrollingToContentEdge) { m_constrainsScrollingToContentEdge = constrainsScrollingToContentEdge; }
64 void setVerticalScrollElasticity(ScrollElasticity scrollElasticity) { m_verticalScrollElasticity = scrollElasticity; }
65 ScrollElasticity verticalScrollElasticity() const { return m_verticalScrollElasticity; }
67 void setHorizontalScrollElasticity(ScrollElasticity scrollElasticity) { m_horizontalScrollElasticity = scrollElasticity; }
68 ScrollElasticity horizontalScrollElasticity() const { return m_horizontalScrollElasticity; }
70 bool inLiveResize() const { return m_inLiveResize; }
71 void willStartLiveResize();
72 void willEndLiveResize();
74 void didAddVerticalScrollbar(Scrollbar*);
75 void willRemoveVerticalScrollbar(Scrollbar*);
76 virtual void didAddHorizontalScrollbar(Scrollbar*);
77 virtual void willRemoveHorizontalScrollbar(Scrollbar*);
79 bool hasOverlayScrollbars() const;
80 virtual void setScrollbarOverlayStyle(ScrollbarOverlayStyle);
81 ScrollbarOverlayStyle scrollbarOverlayStyle() const { return m_scrollbarOverlayStyle; }
83 ScrollAnimator* scrollAnimator() const;
84 const IntPoint& scrollOrigin() const { return m_scrollOrigin; }
86 virtual bool isActive() const = 0;
87 virtual int scrollSize(ScrollbarOrientation) const = 0;
88 virtual int scrollPosition(Scrollbar*) const = 0;
89 void invalidateScrollbar(Scrollbar*, const IntRect&);
90 virtual bool isScrollCornerVisible() const = 0;
91 virtual IntRect scrollCornerRect() const = 0;
92 void invalidateScrollCorner();
93 virtual void getTickmarks(Vector<IntRect>&) const { }
95 // This function should be overriden by subclasses to perform the actual
96 // scroll of the content.
97 virtual void setScrollOffset(const IntPoint&) = 0;
99 // Convert points and rects between the scrollbar and its containing view.
100 // The client needs to implement these in order to be aware of layout effects
101 // like CSS transforms.
102 virtual IntRect convertFromScrollbarToContainingView(const Scrollbar* scrollbar, const IntRect& scrollbarRect) const
104 return scrollbar->Widget::convertToContainingView(scrollbarRect);
106 virtual IntRect convertFromContainingViewToScrollbar(const Scrollbar* scrollbar, const IntRect& parentRect) const
108 return scrollbar->Widget::convertFromContainingView(parentRect);
110 virtual IntPoint convertFromScrollbarToContainingView(const Scrollbar* scrollbar, const IntPoint& scrollbarPoint) const
112 return scrollbar->Widget::convertToContainingView(scrollbarPoint);
114 virtual IntPoint convertFromContainingViewToScrollbar(const Scrollbar* scrollbar, const IntPoint& parentPoint) const
116 return scrollbar->Widget::convertFromContainingView(parentPoint);
119 virtual Scrollbar* horizontalScrollbar() const { return 0; }
120 virtual Scrollbar* verticalScrollbar() const { return 0; }
122 virtual IntPoint scrollPosition() const { ASSERT_NOT_REACHED(); return IntPoint(); }
123 virtual IntPoint minimumScrollPosition() const { ASSERT_NOT_REACHED(); return IntPoint(); }
124 virtual IntPoint maximumScrollPosition() const { ASSERT_NOT_REACHED(); return IntPoint(); }
125 virtual IntRect visibleContentRect(bool /*includeScrollbars*/ = false) const { ASSERT_NOT_REACHED(); return IntRect(); }
126 virtual LayoutUnit visibleHeight() const { ASSERT_NOT_REACHED(); return 0; }
127 virtual LayoutUnit visibleWidth() const { ASSERT_NOT_REACHED(); return 0; }
128 virtual IntSize contentsSize() const { ASSERT_NOT_REACHED(); return IntSize(); }
129 virtual IntSize overhangAmount() const { ASSERT_NOT_REACHED(); return IntSize(); }
130 virtual IntPoint currentMousePosition() const { return IntPoint(); }
132 virtual void didStartRubberBand(const IntSize&) const { ASSERT_NOT_REACHED(); }
133 virtual void didCompleteRubberBand(const IntSize&) const { ASSERT_NOT_REACHED(); }
134 virtual void didStartAnimatedScroll() const { }
135 virtual void didCompleteAnimatedScroll() const { }
137 virtual bool shouldSuspendScrollAnimations() const { return true; }
138 virtual void scrollbarStyleChanged() { }
139 virtual void setVisibleScrollerThumbRect(const IntRect&) { }
141 virtual bool isOnActivePage() const { ASSERT_NOT_REACHED(); return true; }
143 bool isHorizontalScrollerPinnedToMinimumPosition() const { return !horizontalScrollbar() || scrollPosition(horizontalScrollbar()) <= minimumScrollPosition().x(); }
144 bool isHorizontalScrollerPinnedToMaximumPosition() const { return !horizontalScrollbar() || scrollPosition(horizontalScrollbar()) >= maximumScrollPosition().x(); }
145 bool isVerticalScrollerPinnedToMinimumPosition() const { return !verticalScrollbar() || scrollPosition(verticalScrollbar()) <= minimumScrollPosition().y(); }
146 bool isVerticalScrollerPinnedToMaximumPosition() const { return !verticalScrollbar() || scrollPosition(verticalScrollbar()) >= maximumScrollPosition().y(); }
148 // Note that this only returns scrollable areas that can actually be scrolled.
149 virtual ScrollableArea* enclosingScrollableArea() const = 0;
151 bool isPinnedInBothDirections(const IntSize&) const;
152 bool isPinnedHorizontallyInDirection(int horizontalScrollDelta) const;
153 bool isPinnedVerticallyInDirection(int verticalScrollDelta) const;
155 virtual bool shouldRubberBandInDirection(ScrollDirection) const { return true; }
157 virtual void disconnectFromPage() { }
159 virtual bool scrollAnimatorEnabled() const { return false; }
161 // NOTE: Only called from Internals for testing.
162 void setScrollOffsetFromInternals(const IntPoint&);
165 // NOTE: Only called from the ScrollAnimator.
166 friend class ScrollAnimator;
167 void setScrollOffsetFromAnimation(const IntPoint&);
169 mutable OwnPtr<ScrollAnimator> m_scrollAnimator;
170 bool m_constrainsScrollingToContentEdge;
174 ScrollElasticity m_verticalScrollElasticity;
175 ScrollElasticity m_horizontalScrollElasticity;
177 ScrollbarOverlayStyle m_scrollbarOverlayStyle;
180 virtual void invalidateScrollbarRect(Scrollbar*, const IntRect&) = 0;
181 virtual void invalidateScrollCornerRect(const IntRect&) = 0;
183 #if USE(ACCELERATED_COMPOSITING)
184 virtual GraphicsLayer* layerForHorizontalScrollbar() const { return 0; }
185 virtual GraphicsLayer* layerForVerticalScrollbar() const { return 0; }
186 virtual GraphicsLayer* layerForScrollCorner() const { return 0; }
187 #if PLATFORM(CHROMIUM) && ENABLE(RUBBER_BANDING)
188 virtual GraphicsLayer* layerForOverhangAreas() const { return 0; }
191 bool hasLayerForHorizontalScrollbar() const;
192 bool hasLayerForVerticalScrollbar() const;
193 bool hasLayerForScrollCorner() const;
195 // There are 8 possible combinations of writing mode and direction. Scroll origin will be non-zero in the x or y axis
196 // if there is any reversed direction or writing-mode. The combinations are:
197 // writing-mode / direction scrollOrigin.x() set scrollOrigin.y() set
198 // horizontal-tb / ltr NO NO
199 // horizontal-tb / rtl YES NO
200 // horizontal-bt / ltr NO YES
201 // horizontal-bt / rtl YES YES
202 // vertical-lr / ltr NO NO
203 // vertical-lr / rtl NO YES
204 // vertical-rl / ltr YES NO
205 // vertical-rl / rtl YES YES
206 IntPoint m_scrollOrigin;
209 } // namespace WebCore
211 #endif // ScrollableArea_h