• Home
  • Line#
  • Scopes#
  • Navigate#
  • Raw
  • Download
1 /*
2  * Copyright (C) 2004, 2006, 2007, 2008 Apple Inc. All rights reserved.
3  * Copyright (C) 2009 Holger Hans Peter Freyther
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  *
14  * THIS SOFTWARE IS PROVIDED BY APPLE COMPUTER, INC. ``AS IS'' AND ANY
15  * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
17  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE COMPUTER, INC. OR
18  * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
19  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
20  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
21  * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
22  * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
23  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
24  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
25  */
26 
27 #ifndef ScrollView_h
28 #define ScrollView_h
29 
30 #include "platform/PlatformExport.h"
31 #include "platform/Widget.h"
32 #include "platform/geometry/IntRect.h"
33 #include "platform/scroll/ScrollTypes.h"
34 #include "platform/scroll/ScrollableArea.h"
35 #include "platform/scroll/Scrollbar.h"
36 
37 #include "wtf/HashSet.h"
38 #include "wtf/TemporaryChange.h"
39 
40 namespace blink {
41 
42 class Scrollbar;
43 
44 class PLATFORM_EXPORT ScrollView : public Widget, public ScrollableArea {
45 public:
46     virtual ~ScrollView();
47 
48     // ScrollableArea functions.
49     virtual int scrollSize(ScrollbarOrientation) const OVERRIDE;
50     virtual void setScrollOffset(const IntPoint&) OVERRIDE;
51     virtual bool isScrollCornerVisible() const OVERRIDE;
52     virtual void scrollbarStyleChanged() OVERRIDE;
53     virtual bool userInputScrollable(ScrollbarOrientation) const OVERRIDE;
54     virtual bool shouldPlaceVerticalScrollbarOnLeft() const OVERRIDE;
55 
56     virtual void notifyPageThatContentAreaWillPaint() const;
57 
58     // The window that hosts the ScrollView. The ScrollView will communicate scrolls and repaints to the
59     // host window in the window's coordinate space.
60     virtual HostWindow* hostWindow() const = 0;
61 
62     // Returns a clip rect in host window coordinates. Used to clip the blit on a scroll.
63     virtual IntRect windowClipRect(IncludeScrollbarsInRect = ExcludeScrollbars) const = 0;
64 
65     // Functions for child manipulation and inspection.
children()66     const HashSet<RefPtr<Widget> >* children() const { return &m_children; }
67     virtual void addChild(PassRefPtr<Widget>);
68     virtual void removeChild(Widget*);
69 
70     // If the scroll view does not use a native widget, then it will have cross-platform Scrollbars. These functions
71     // can be used to obtain those scrollbars.
horizontalScrollbar()72     virtual Scrollbar* horizontalScrollbar() const OVERRIDE { return m_horizontalScrollbar.get(); }
verticalScrollbar()73     virtual Scrollbar* verticalScrollbar() const OVERRIDE { return m_verticalScrollbar.get(); }
isScrollViewScrollbar(const Widget * child)74     bool isScrollViewScrollbar(const Widget* child) const { return horizontalScrollbar() == child || verticalScrollbar() == child; }
75 
76     void positionScrollbarLayers();
77 
78     // Functions for setting and retrieving the scrolling mode in each axis (horizontal/vertical). The mode has values of
79     // AlwaysOff, AlwaysOn, and Auto. AlwaysOff means never show a scrollbar, AlwaysOn means always show a scrollbar.
80     // Auto means show a scrollbar only when one is needed.
81     // Note that for platforms with native widgets, these modes are considered advisory. In other words the underlying native
82     // widget may choose not to honor the requested modes.
83     void setScrollbarModes(ScrollbarMode horizontalMode, ScrollbarMode verticalMode, bool horizontalLock = false, bool verticalLock = false);
84     void setHorizontalScrollbarMode(ScrollbarMode mode, bool lock = false) { setScrollbarModes(mode, verticalScrollbarMode(), lock, verticalScrollbarLock()); }
85     void setVerticalScrollbarMode(ScrollbarMode mode, bool lock = false) { setScrollbarModes(horizontalScrollbarMode(), mode, horizontalScrollbarLock(), lock); };
86     void scrollbarModes(ScrollbarMode& horizontalMode, ScrollbarMode& verticalMode) const;
horizontalScrollbarMode()87     ScrollbarMode horizontalScrollbarMode() const { ScrollbarMode horizontal, vertical; scrollbarModes(horizontal, vertical); return horizontal; }
verticalScrollbarMode()88     ScrollbarMode verticalScrollbarMode() const { ScrollbarMode horizontal, vertical; scrollbarModes(horizontal, vertical); return vertical; }
89 
90     void setHorizontalScrollbarLock(bool lock = true) { m_horizontalScrollbarLock = lock; }
horizontalScrollbarLock()91     bool horizontalScrollbarLock() const { return m_horizontalScrollbarLock; }
92     void setVerticalScrollbarLock(bool lock = true) { m_verticalScrollbarLock = lock; }
verticalScrollbarLock()93     bool verticalScrollbarLock() const { return m_verticalScrollbarLock; }
94 
95     void setScrollingModesLock(bool lock = true) { m_horizontalScrollbarLock = m_verticalScrollbarLock = lock; }
96 
97     virtual void setCanHaveScrollbars(bool);
canHaveScrollbars()98     bool canHaveScrollbars() const { return horizontalScrollbarMode() != ScrollbarAlwaysOff || verticalScrollbarMode() != ScrollbarAlwaysOff; }
99 
100     // By default, paint events are clipped to the visible area.  If set to
101     // false, paint events are no longer clipped.
clipsPaintInvalidations()102     bool clipsPaintInvalidations() const { return m_clipsRepaints; }
103     void setClipsRepaints(bool);
104 
105     // Overridden by FrameView to create custom CSS scrollbars if applicable.
106     virtual PassRefPtr<Scrollbar> createScrollbar(ScrollbarOrientation);
107 
108     // The visible content rect has a location that is the scrolled offset of the document. The width and height are the viewport width
109     // and height. By default the scrollbars themselves are excluded from this rectangle, but an optional boolean argument allows them to be
110     // included.
111     virtual IntRect visibleContentRect(IncludeScrollbarsInRect = ExcludeScrollbars) const OVERRIDE;
visibleSize()112     IntSize visibleSize() const { return visibleContentRect().size(); }
113 
114     // visibleContentRect().size() is computed from unscaledVisibleContentSize() divided by the value of visibleContentScaleFactor.
115     // For the main frame, visibleContentScaleFactor is equal to the page's pageScaleFactor; it's 1 otherwise.
116     IntSize unscaledVisibleContentSize(IncludeScrollbarsInRect = ExcludeScrollbars) const;
visibleContentScaleFactor()117     virtual float visibleContentScaleFactor() const { return 1; }
118 
119     // Offset used to convert incoming input events while emulating device metics.
inputEventsOffsetForEmulation()120     virtual IntSize inputEventsOffsetForEmulation() const { return IntSize(); }
121 
122     // Scale used to convert incoming input events. Usually the same as visibleContentScaleFactor(), unless specifically changed.
inputEventsScaleFactor()123     virtual float inputEventsScaleFactor() const { return visibleContentScaleFactor(); }
124 
125     // Functions for getting/setting the size of the document contained inside the ScrollView (as an IntSize or as individual width and height
126     // values).
127     virtual IntSize contentsSize() const OVERRIDE; // Always at least as big as the visibleWidth()/visibleHeight().
contentsWidth()128     int contentsWidth() const { return contentsSize().width(); }
contentsHeight()129     int contentsHeight() const { return contentsSize().height(); }
130     virtual void setContentsSize(const IntSize&);
131 
132     // Functions for querying the current scrolled position (both as a point, a size, or as individual X and Y values).
scrollPosition()133     virtual IntPoint scrollPosition() const OVERRIDE { return visibleContentRect().location(); }
scrollOffset()134     IntSize scrollOffset() const { return toIntSize(visibleContentRect().location()); } // Gets the scrolled position as an IntSize. Convenient for adding to other sizes.
pendingScrollDelta()135     IntSize pendingScrollDelta() const { return m_pendingScrollDelta; }
136     virtual IntPoint maximumScrollPosition() const OVERRIDE; // The maximum position we can be scrolled to.
137     virtual IntPoint minimumScrollPosition() const OVERRIDE; // The minimum position we can be scrolled to.
138     // Adjust the passed in scroll position to keep it between the minimum and maximum positions.
139     IntPoint adjustScrollPositionWithinRange(const IntPoint&) const;
scrollX()140     int scrollX() const { return scrollPosition().x(); }
scrollY()141     int scrollY() const { return scrollPosition().y(); }
142 
143     virtual IntSize overhangAmount() const OVERRIDE;
144 
cacheCurrentScrollPosition()145     void cacheCurrentScrollPosition() { m_cachedScrollPosition = scrollPosition(); }
cachedScrollPosition()146     IntPoint cachedScrollPosition() const { return m_cachedScrollPosition; }
147 
148     // Functions for scrolling the view.
149     virtual void setScrollPosition(const IntPoint&, ScrollBehavior = ScrollBehaviorInstant);
150     void scrollBy(const IntSize& s, ScrollBehavior behavior = ScrollBehaviorInstant)
151     {
152         return setScrollPosition(scrollPosition() + s, behavior);
153     }
154 
155     bool scroll(ScrollDirection, ScrollGranularity);
156 
157     // Scroll the actual contents of the view (either blitting or invalidating as needed).
158     void scrollContents(const IntSize& scrollDelta);
159 
160     // This gives us a means of blocking painting on our scrollbars until the first layout has occurred.
161     void setScrollbarsSuppressed(bool suppressed, bool repaintOnUnsuppress = false);
scrollbarsSuppressed()162     bool scrollbarsSuppressed() const { return m_scrollbarsSuppressed; }
163 
164     IntPoint rootViewToContents(const IntPoint&) const;
165     IntPoint contentsToRootView(const IntPoint&) const;
166     IntRect rootViewToContents(const IntRect&) const;
167     IntRect contentsToRootView(const IntRect&) const;
168 
169     // Event coordinates are assumed to be in the coordinate space of a window that contains
170     // the entire widget hierarchy. It is up to the platform to decide what the precise definition
171     // of containing window is. (For example on Mac it is the containing NSWindow.)
172     IntPoint windowToContents(const IntPoint&) const;
173     FloatPoint windowToContents(const FloatPoint&) const;
174     IntPoint contentsToWindow(const IntPoint&) const;
175     IntRect windowToContents(const IntRect&) const;
176     IntRect contentsToWindow(const IntRect&) const;
177 
178     // Functions for converting to screen coordinates.
179     IntRect contentsToScreen(const IntRect&) const;
180 
181     // These functions are used to enable scrollbars to avoid window resizer controls that overlap the scroll view. This happens on Mac
182     // for example.
windowResizerRect()183     virtual IntRect windowResizerRect() const { return IntRect(); }
184     bool containsScrollbarsAvoidingResizer() const;
185     void adjustScrollbarsAvoidingResizerCount(int overlapDelta);
186     void windowResizerRectChanged();
187 
188     virtual void setParent(Widget*) OVERRIDE; // Overridden to update the overlapping scrollbar count.
189 
190     // Called when our frame rect changes (or the rect/scroll position of an ancestor changes).
191     virtual void frameRectsChanged() OVERRIDE;
192 
193     // Widget override to update our scrollbars and notify our contents of the resize.
194     virtual void setFrameRect(const IntRect&) OVERRIDE;
195 
196     // For platforms that need to hit test scrollbars from within the engine's event handlers (like Win32).
197     Scrollbar* scrollbarAtWindowPoint(const IntPoint& windowPoint);
198     Scrollbar* scrollbarAtViewPoint(const IntPoint& viewPoint);
199 
convertChildToSelf(const Widget * child,const IntPoint & point)200     virtual IntPoint convertChildToSelf(const Widget* child, const IntPoint& point) const OVERRIDE
201     {
202         IntPoint newPoint = point;
203         if (!isScrollViewScrollbar(child))
204             newPoint = point - scrollOffset();
205         newPoint.moveBy(child->location());
206         return newPoint;
207     }
208 
convertSelfToChild(const Widget * child,const IntPoint & point)209     virtual IntPoint convertSelfToChild(const Widget* child, const IntPoint& point) const OVERRIDE
210     {
211         IntPoint newPoint = point;
212         if (!isScrollViewScrollbar(child))
213             newPoint = point + scrollOffset();
214         newPoint.moveBy(-child->location());
215         return newPoint;
216     }
217 
218     // Widget override. Handles painting of the contents of the view as well as the scrollbars.
219     virtual void paint(GraphicsContext*, const IntRect&) OVERRIDE;
220     void paintScrollbars(GraphicsContext*, const IntRect&);
221 
222     // Widget overrides to ensure that our children's visibility status is kept up to date when we get shown and hidden.
223     virtual void show() OVERRIDE;
224     virtual void hide() OVERRIDE;
225     virtual void setParentVisible(bool) OVERRIDE;
226 
227     // Pan scrolling.
228     static const int noPanScrollRadius = 15;
229     void addPanScrollIcon(const IntPoint&);
230     void removePanScrollIcon();
231     void paintPanScrollIcon(GraphicsContext*);
232 
233     virtual bool isPointInScrollbarCorner(const IntPoint&);
234     virtual bool scrollbarCornerPresent() const;
235     virtual IntRect scrollCornerRect() const OVERRIDE;
236     virtual void paintScrollCorner(GraphicsContext*, const IntRect& cornerRect);
237     virtual void paintScrollbar(GraphicsContext*, Scrollbar*, const IntRect&);
238 
239     virtual IntRect convertFromScrollbarToContainingView(const Scrollbar*, const IntRect&) const OVERRIDE;
240     virtual IntRect convertFromContainingViewToScrollbar(const Scrollbar*, const IntRect&) const OVERRIDE;
241     virtual IntPoint convertFromScrollbarToContainingView(const Scrollbar*, const IntPoint&) const OVERRIDE;
242     virtual IntPoint convertFromContainingViewToScrollbar(const Scrollbar*, const IntPoint&) const OVERRIDE;
243 
244     void calculateAndPaintOverhangAreas(GraphicsContext*, const IntRect& dirtyRect);
245     void calculateAndPaintOverhangBackground(GraphicsContext*, const IntRect& dirtyRect);
246 
isScrollView()247     virtual bool isScrollView() const OVERRIDE FINAL { return true; }
248 
249 protected:
250     ScrollView();
251 
252     // NOTE: This should only be called by the overriden setScrollOffset from ScrollableArea.
253     virtual void scrollTo(const IntSize& newOffset);
254 
255     virtual void contentRectangleForPaintInvalidation(const IntRect&);
256     virtual void paintContents(GraphicsContext*, const IntRect& damageRect) = 0;
257 
258     virtual void paintOverhangAreas(GraphicsContext*, const IntRect& horizontalOverhangArea, const IntRect& verticalOverhangArea, const IntRect& dirtyRect);
259 
260     virtual void scrollbarExistenceDidChange() = 0;
261     // These functions are used to create/destroy scrollbars.
262     void setHasHorizontalScrollbar(bool);
263     void setHasVerticalScrollbar(bool);
264 
265     virtual void updateScrollCorner();
266     virtual void invalidateScrollCornerRect(const IntRect&) OVERRIDE;
267 
268     virtual void scrollContentsIfNeeded();
269     // Scroll the content by via the compositor.
scrollContentsFastPath(const IntSize & scrollDelta)270     virtual bool scrollContentsFastPath(const IntSize& scrollDelta) { return true; }
271     // Scroll the content by invalidating everything.
272     virtual void scrollContentsSlowPath(const IntRect& updateRect);
273 
274     void setScrollOrigin(const IntPoint&, bool updatePositionAtAll, bool updatePositionSynchronously);
275 
276     // Subclassed by FrameView to check the writing-mode of the document.
isVerticalDocument()277     virtual bool isVerticalDocument() const { return true; }
isFlippedDocument()278     virtual bool isFlippedDocument() const { return false; }
279 
280     enum ComputeScrollbarExistenceOption {
281         FirstPass,
282         Incremental
283     };
284     void computeScrollbarExistence(bool& newHasHorizontalScrollbar, bool& newHasVerticalScrollbar, const IntSize& docSize, ComputeScrollbarExistenceOption = FirstPass) const;
285     void updateScrollbarGeometry();
286 
287     // Called to update the scrollbars to accurately reflect the state of the view.
288     void updateScrollbars(const IntSize& desiredOffset);
289 
290     IntSize excludeScrollbars(const IntSize&) const;
291 
292     class InUpdateScrollbarsScope {
293     public:
InUpdateScrollbarsScope(ScrollView * view)294         explicit InUpdateScrollbarsScope(ScrollView* view)
295             : m_scope(view->m_inUpdateScrollbars, true)
296         { }
297     private:
298         TemporaryChange<bool> m_scope;
299     };
300 
scrollbarsDisabled()301     virtual bool scrollbarsDisabled() const { return false; }
302 
303 private:
304     bool adjustScrollbarExistence(ComputeScrollbarExistenceOption = FirstPass);
305     void adjustScrollbarOpacity();
306     // FIXME(bokan): setScrollOffset, setScrollPosition, scrollTo, scrollToOffsetWithoutAnimation,
307     // notifyScrollPositionChanged...there's too many ways to scroll this class. This needs
308     // some cleanup.
309     void setScrollOffsetFromUpdateScrollbars(const IntSize&);
310 
311     RefPtr<Scrollbar> m_horizontalScrollbar;
312     RefPtr<Scrollbar> m_verticalScrollbar;
313     ScrollbarMode m_horizontalScrollbarMode;
314     ScrollbarMode m_verticalScrollbarMode;
315 
316     bool m_horizontalScrollbarLock;
317     bool m_verticalScrollbarLock;
318 
319     HashSet<RefPtr<Widget> > m_children;
320 
321     IntSize m_pendingScrollDelta;
322     IntSize m_scrollOffset; // FIXME: Would rather store this as a position, but we will wait to make this change until more code is shared.
323     IntPoint m_cachedScrollPosition;
324     IntSize m_contentsSize;
325 
326     int m_scrollbarsAvoidingResizer;
327     bool m_scrollbarsSuppressed;
328 
329     bool m_inUpdateScrollbars;
330 
331     IntPoint m_panScrollIconPoint;
332     bool m_drawPanScrollIcon;
333 
334     bool m_clipsRepaints;
335 
336     void init();
337     void destroy();
338 
339     IntRect rectToCopyOnScroll() const;
340 
341     void calculateOverhangAreasForPainting(IntRect& horizontalOverhangRect, IntRect& verticalOverhangRect);
342     void updateOverhangAreas();
343 }; // class ScrollView
344 
345 DEFINE_TYPE_CASTS(ScrollView, Widget, widget, widget->isScrollView(), widget.isScrollView());
346 
347 } // namespace blink
348 
349 #endif // ScrollView_h
350