1 /* 2 * Copyright (C) 2008, 2011 Apple Inc. All Rights Reserved. 3 * 4 * Redistribution and use in source and binary forms, with or without 5 * modification, are permitted provided that the following conditions 6 * are met: 7 * 1. Redistributions of source code must retain the above copyright 8 * notice, this list of conditions and the following disclaimer. 9 * 2. Redistributions in binary form must reproduce the above copyright 10 * notice, this list of conditions and the following disclaimer in the 11 * documentation and/or other materials provided with the distribution. 12 * 13 * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY 14 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 15 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 16 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR 17 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, 18 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, 19 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR 20 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY 21 * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 22 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 23 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 24 */ 25 26 #ifndef ScrollableArea_h 27 #define ScrollableArea_h 28 29 #include "platform/PlatformExport.h" 30 #include "platform/scroll/ScrollAnimator.h" 31 #include "platform/scroll/Scrollbar.h" 32 #include "wtf/Noncopyable.h" 33 #include "wtf/Vector.h" 34 35 namespace WebCore { 36 37 class FloatPoint; 38 class GraphicsContext; 39 class GraphicsLayer; 40 class PlatformGestureEvent; 41 class PlatformWheelEvent; 42 class ScrollAnimator; 43 44 enum ScrollBehavior { 45 ScrollBehaviorAuto, 46 ScrollBehaviorInstant, 47 ScrollBehaviorSmooth, 48 }; 49 50 enum IncludeScrollbarsInRect { 51 ExcludeScrollbars, 52 IncludeScrollbars, 53 }; 54 55 class PLATFORM_EXPORT ScrollableArea { 56 WTF_MAKE_NONCOPYABLE(ScrollableArea); 57 public: 58 static int pixelsPerLineStep(); 59 static float minFractionToStepWhenPaging(); 60 static int maxOverlapBetweenPages(); 61 62 bool scroll(ScrollDirection, ScrollGranularity, float delta = 1); 63 void scrollToOffsetWithoutAnimation(const FloatPoint&); 64 void scrollToOffsetWithoutAnimation(ScrollbarOrientation, float offset); 65 66 // Should be called when the scroll position changes externally, for example if the scroll layer position 67 // is updated on the scrolling thread and we need to notify the main thread. 68 void notifyScrollPositionChanged(const IntPoint&); 69 70 static bool scrollBehaviorFromString(const String&, ScrollBehavior&); 71 72 bool handleWheelEvent(const PlatformWheelEvent&); 73 74 // Functions for controlling if you can scroll past the end of the document. constrainsScrollingToContentEdge()75 bool constrainsScrollingToContentEdge() const { return m_constrainsScrollingToContentEdge; } setConstrainsScrollingToContentEdge(bool constrainsScrollingToContentEdge)76 void setConstrainsScrollingToContentEdge(bool constrainsScrollingToContentEdge) { m_constrainsScrollingToContentEdge = constrainsScrollingToContentEdge; } 77 setVerticalScrollElasticity(ScrollElasticity scrollElasticity)78 void setVerticalScrollElasticity(ScrollElasticity scrollElasticity) { m_verticalScrollElasticity = scrollElasticity; } verticalScrollElasticity()79 ScrollElasticity verticalScrollElasticity() const { return static_cast<ScrollElasticity>(m_verticalScrollElasticity); } 80 setHorizontalScrollElasticity(ScrollElasticity scrollElasticity)81 void setHorizontalScrollElasticity(ScrollElasticity scrollElasticity) { m_horizontalScrollElasticity = scrollElasticity; } horizontalScrollElasticity()82 ScrollElasticity horizontalScrollElasticity() const { return static_cast<ScrollElasticity>(m_horizontalScrollElasticity); } 83 inLiveResize()84 bool inLiveResize() const { return m_inLiveResize; } 85 void willStartLiveResize(); 86 void willEndLiveResize(); 87 88 void contentAreaWillPaint() const; 89 void mouseEnteredContentArea() const; 90 void mouseExitedContentArea() const; 91 void mouseMovedInContentArea() const; 92 void mouseEnteredScrollbar(Scrollbar*) const; 93 void mouseExitedScrollbar(Scrollbar*) const; 94 void contentAreaDidShow() const; 95 void contentAreaDidHide() const; 96 97 void finishCurrentScrollAnimations() const; 98 99 virtual void didAddScrollbar(Scrollbar*, ScrollbarOrientation); 100 virtual void willRemoveScrollbar(Scrollbar*, ScrollbarOrientation); 101 102 virtual void contentsResized(); 103 104 bool hasOverlayScrollbars() const; 105 void setScrollbarOverlayStyle(ScrollbarOverlayStyle); scrollbarOverlayStyle()106 ScrollbarOverlayStyle scrollbarOverlayStyle() const { return static_cast<ScrollbarOverlayStyle>(m_scrollbarOverlayStyle); } 107 108 // This getter will create a ScrollAnimator if it doesn't already exist. 109 ScrollAnimator* scrollAnimator() const; 110 111 // This getter will return null if the ScrollAnimator hasn't been created yet. existingScrollAnimator()112 ScrollAnimator* existingScrollAnimator() const { return m_scrollAnimator.get(); } 113 scrollOrigin()114 const IntPoint& scrollOrigin() const { return m_scrollOrigin; } scrollOriginChanged()115 bool scrollOriginChanged() const { return m_scrollOriginChanged; } 116 117 // FIXME(bokan): Meaningless name, rename to isActiveFocus 118 virtual bool isActive() const = 0; 119 virtual int scrollSize(ScrollbarOrientation) const = 0; 120 virtual void invalidateScrollbar(Scrollbar*, const IntRect&); 121 virtual bool isScrollCornerVisible() const = 0; 122 virtual IntRect scrollCornerRect() const = 0; 123 virtual void invalidateScrollCorner(const IntRect&); getTickmarks(Vector<IntRect> &)124 virtual void getTickmarks(Vector<IntRect>&) const { } 125 126 // Convert points and rects between the scrollbar and its containing view. 127 // The client needs to implement these in order to be aware of layout effects 128 // like CSS transforms. convertFromScrollbarToContainingView(const Scrollbar * scrollbar,const IntRect & scrollbarRect)129 virtual IntRect convertFromScrollbarToContainingView(const Scrollbar* scrollbar, const IntRect& scrollbarRect) const 130 { 131 return scrollbar->Widget::convertToContainingView(scrollbarRect); 132 } convertFromContainingViewToScrollbar(const Scrollbar * scrollbar,const IntRect & parentRect)133 virtual IntRect convertFromContainingViewToScrollbar(const Scrollbar* scrollbar, const IntRect& parentRect) const 134 { 135 return scrollbar->Widget::convertFromContainingView(parentRect); 136 } convertFromScrollbarToContainingView(const Scrollbar * scrollbar,const IntPoint & scrollbarPoint)137 virtual IntPoint convertFromScrollbarToContainingView(const Scrollbar* scrollbar, const IntPoint& scrollbarPoint) const 138 { 139 return scrollbar->Widget::convertToContainingView(scrollbarPoint); 140 } convertFromContainingViewToScrollbar(const Scrollbar * scrollbar,const IntPoint & parentPoint)141 virtual IntPoint convertFromContainingViewToScrollbar(const Scrollbar* scrollbar, const IntPoint& parentPoint) const 142 { 143 return scrollbar->Widget::convertFromContainingView(parentPoint); 144 } 145 horizontalScrollbar()146 virtual Scrollbar* horizontalScrollbar() const { return 0; } verticalScrollbar()147 virtual Scrollbar* verticalScrollbar() const { return 0; } 148 149 // scrollPosition is relative to the scrollOrigin. i.e. If the page is RTL 150 // then scrollPosition will be negative. 151 virtual IntPoint scrollPosition() const = 0; 152 virtual IntPoint minimumScrollPosition() const = 0; 153 virtual IntPoint maximumScrollPosition() const = 0; 154 155 virtual IntRect visibleContentRect(IncludeScrollbarsInRect = ExcludeScrollbars) const; 156 virtual int visibleHeight() const = 0; 157 virtual int visibleWidth() const = 0; 158 virtual IntSize contentsSize() const = 0; overhangAmount()159 virtual IntSize overhangAmount() const { return IntSize(); } lastKnownMousePosition()160 virtual IntPoint lastKnownMousePosition() const { return IntPoint(); } 161 shouldSuspendScrollAnimations()162 virtual bool shouldSuspendScrollAnimations() const { return true; } scrollbarStyleChanged()163 virtual void scrollbarStyleChanged() { } 164 165 virtual bool scrollbarsCanBeActive() const = 0; 166 167 // Returns the bounding box of this scrollable area, in the coordinate system of the enclosing scroll view. 168 virtual IntRect scrollableAreaBoundingBox() const = 0; 169 isRubberBandInProgress()170 virtual bool isRubberBandInProgress() const { return false; } 171 scrollAnimatorEnabled()172 virtual bool scrollAnimatorEnabled() const { return false; } 173 174 // NOTE: Only called from Internals for testing. 175 void setScrollOffsetFromInternals(const IntPoint&); 176 177 IntPoint clampScrollPosition(const IntPoint&) const; 178 179 // Let subclasses provide a way of asking for and servicing scroll 180 // animations. scheduleAnimation()181 virtual bool scheduleAnimation() { return false; } 182 void serviceScrollAnimations(); 183 usesCompositedScrolling()184 virtual bool usesCompositedScrolling() const { return false; } 185 updateAfterCompositingChange()186 virtual void updateAfterCompositingChange() { } 187 188 virtual bool userInputScrollable(ScrollbarOrientation) const = 0; 189 virtual bool shouldPlaceVerticalScrollbarOnLeft() const = 0; 190 191 // Convenience functions scrollPosition(ScrollbarOrientation orientation)192 int scrollPosition(ScrollbarOrientation orientation) { return orientation == HorizontalScrollbar ? scrollPosition().x() : scrollPosition().y(); } minimumScrollPosition(ScrollbarOrientation orientation)193 int minimumScrollPosition(ScrollbarOrientation orientation) { return orientation == HorizontalScrollbar ? minimumScrollPosition().x() : minimumScrollPosition().y(); } maximumScrollPosition(ScrollbarOrientation orientation)194 int maximumScrollPosition(ScrollbarOrientation orientation) { return orientation == HorizontalScrollbar ? maximumScrollPosition().x() : maximumScrollPosition().y(); } clampScrollPosition(ScrollbarOrientation orientation,int pos)195 int clampScrollPosition(ScrollbarOrientation orientation, int pos) { return std::max(std::min(pos, maximumScrollPosition(orientation)), minimumScrollPosition(orientation)); } 196 hasVerticalBarDamage()197 bool hasVerticalBarDamage() const { return m_hasVerticalBarDamage; } hasHorizontalBarDamage()198 bool hasHorizontalBarDamage() const { return m_hasHorizontalBarDamage; } 199 verticalBarDamage()200 const IntRect& verticalBarDamage() const 201 { 202 ASSERT(m_hasVerticalBarDamage); 203 return m_verticalBarDamage; 204 } 205 horizontalBarDamage()206 const IntRect& horizontalBarDamage() const 207 { 208 ASSERT(m_hasHorizontalBarDamage); 209 return m_horizontalBarDamage; 210 } 211 resetScrollbarDamage()212 void resetScrollbarDamage() 213 { 214 m_hasVerticalBarDamage = false; 215 m_hasHorizontalBarDamage = false; 216 } 217 virtual GraphicsLayer* layerForContainer() const; layerForScrolling()218 virtual GraphicsLayer* layerForScrolling() const { return 0; } layerForHorizontalScrollbar()219 virtual GraphicsLayer* layerForHorizontalScrollbar() const { return 0; } layerForVerticalScrollbar()220 virtual GraphicsLayer* layerForVerticalScrollbar() const { return 0; } layerForScrollCorner()221 virtual GraphicsLayer* layerForScrollCorner() const { return 0; } 222 bool hasLayerForHorizontalScrollbar() const; 223 bool hasLayerForVerticalScrollbar() const; 224 bool hasLayerForScrollCorner() const; 225 226 protected: 227 ScrollableArea(); 228 virtual ~ScrollableArea(); 229 230 void setScrollOrigin(const IntPoint&); resetScrollOriginChanged()231 void resetScrollOriginChanged() { m_scrollOriginChanged = false; } 232 233 virtual void invalidateScrollbarRect(Scrollbar*, const IntRect&) = 0; 234 virtual void invalidateScrollCornerRect(const IntRect&) = 0; 235 236 // For repaint after layout, stores the damage to be repainted for the 237 // scrollbars. 238 unsigned m_hasHorizontalBarDamage : 1; 239 unsigned m_hasVerticalBarDamage : 1; 240 IntRect m_horizontalBarDamage; 241 IntRect m_verticalBarDamage; 242 243 private: 244 void scrollPositionChanged(const IntPoint&); 245 246 // NOTE: Only called from the ScrollAnimator. 247 friend class ScrollAnimator; 248 void setScrollOffsetFromAnimation(const IntPoint&); 249 250 // This function should be overriden by subclasses to perform the actual 251 // scroll of the content. 252 virtual void setScrollOffset(const IntPoint&) = 0; 253 254 virtual int lineStep(ScrollbarOrientation) const; 255 virtual int pageStep(ScrollbarOrientation) const; 256 virtual int documentStep(ScrollbarOrientation) const; 257 virtual float pixelStep(ScrollbarOrientation) const; 258 259 mutable OwnPtr<ScrollAnimator> m_scrollAnimator; 260 unsigned m_constrainsScrollingToContentEdge : 1; 261 262 unsigned m_inLiveResize : 1; 263 264 unsigned m_verticalScrollElasticity : 2; // ScrollElasticity 265 unsigned m_horizontalScrollElasticity : 2; // ScrollElasticity 266 267 unsigned m_scrollbarOverlayStyle : 2; // ScrollbarOverlayStyle 268 269 unsigned m_scrollOriginChanged : 1; 270 271 // There are 8 possible combinations of writing mode and direction. Scroll origin will be non-zero in the x or y axis 272 // if there is any reversed direction or writing-mode. The combinations are: 273 // writing-mode / direction scrollOrigin.x() set scrollOrigin.y() set 274 // horizontal-tb / ltr NO NO 275 // horizontal-tb / rtl YES NO 276 // horizontal-bt / ltr NO YES 277 // horizontal-bt / rtl YES YES 278 // vertical-lr / ltr NO NO 279 // vertical-lr / rtl NO YES 280 // vertical-rl / ltr YES NO 281 // vertical-rl / rtl YES YES 282 IntPoint m_scrollOrigin; 283 }; 284 285 } // namespace WebCore 286 287 #endif // ScrollableArea_h 288