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 "IntRect.h"
31#include "Scrollbar.h"
32#include "ScrollableArea.h"
33#include "ScrollTypes.h"
34#include "Widget.h"
35
36#include <wtf/HashSet.h>
37
38#if PLATFORM(MAC) && defined __OBJC__
39@protocol WebCoreFrameScrollView;
40#endif
41
42#if PLATFORM(GTK)
43#include "GRefPtrGtk.h"
44typedef struct _GtkAdjustment GtkAdjustment;
45#endif
46
47#if PLATFORM(WX)
48class wxScrollWinEvent;
49#endif
50
51namespace WebCore {
52
53class HostWindow;
54class Scrollbar;
55
56#if PLATFORM(ANDROID)
57class FrameView;
58#endif
59
60class ScrollView : public Widget, public ScrollableArea {
61public:
62    ~ScrollView();
63
64    // ScrollableArea functions.  FrameView overrides the others.
65    virtual int scrollSize(ScrollbarOrientation orientation) const;
66    virtual int scrollPosition(Scrollbar*) const;
67    virtual void setScrollOffset(const IntPoint&);
68    virtual void didCompleteRubberBand(const IntSize&) const;
69    virtual void notifyPageThatContentAreaWillPaint() const;
70    virtual bool isScrollCornerVisible() const;
71
72    // NOTE: This should only be called by the overriden setScrollOffset from ScrollableArea.
73    virtual void scrollTo(const IntSize& newOffset);
74
75    // The window thats hosts the ScrollView. The ScrollView will communicate scrolls and repaints to the
76    // host window in the window's coordinate space.
77    virtual HostWindow* hostWindow() const = 0;
78
79    // Returns a clip rect in host window coordinates. Used to clip the blit on a scroll.
80    virtual IntRect windowClipRect(bool clipToContents = true) const = 0;
81
82    // Functions for child manipulation and inspection.
83    const HashSet<RefPtr<Widget> >* children() const { return &m_children; }
84    void addChild(PassRefPtr<Widget>);
85    void removeChild(Widget*);
86
87    // If the scroll view does not use a native widget, then it will have cross-platform Scrollbars. These functions
88    // can be used to obtain those scrollbars.
89    virtual Scrollbar* horizontalScrollbar() const { return m_horizontalScrollbar.get(); }
90    virtual Scrollbar* verticalScrollbar() const { return m_verticalScrollbar.get(); }
91    bool isScrollViewScrollbar(const Widget* child) const { return horizontalScrollbar() == child || verticalScrollbar() == child; }
92
93    void positionScrollbarLayers();
94
95    // Functions for setting and retrieving the scrolling mode in each axis (horizontal/vertical). The mode has values of
96    // AlwaysOff, AlwaysOn, and Auto. AlwaysOff means never show a scrollbar, AlwaysOn means always show a scrollbar.
97    // Auto means show a scrollbar only when one is needed.
98    // Note that for platforms with native widgets, these modes are considered advisory. In other words the underlying native
99    // widget may choose not to honor the requested modes.
100    void setScrollbarModes(ScrollbarMode horizontalMode, ScrollbarMode verticalMode, bool horizontalLock = false, bool verticalLock = false);
101    void setHorizontalScrollbarMode(ScrollbarMode mode, bool lock = false) { setScrollbarModes(mode, verticalScrollbarMode(), lock, verticalScrollbarLock()); }
102    void setVerticalScrollbarMode(ScrollbarMode mode, bool lock = false) { setScrollbarModes(horizontalScrollbarMode(), mode, horizontalScrollbarLock(), lock); };
103    void scrollbarModes(ScrollbarMode& horizontalMode, ScrollbarMode& verticalMode) const;
104    ScrollbarMode horizontalScrollbarMode() const { ScrollbarMode horizontal, vertical; scrollbarModes(horizontal, vertical); return horizontal; }
105    ScrollbarMode verticalScrollbarMode() const { ScrollbarMode horizontal, vertical; scrollbarModes(horizontal, vertical); return vertical; }
106
107    void setHorizontalScrollbarLock(bool lock = true) { m_horizontalScrollbarLock = lock; }
108    bool horizontalScrollbarLock() const { return m_horizontalScrollbarLock; }
109    void setVerticalScrollbarLock(bool lock = true) { m_verticalScrollbarLock = lock; }
110    bool verticalScrollbarLock() const { return m_verticalScrollbarLock; }
111
112    void setScrollingModesLock(bool lock = true) { m_horizontalScrollbarLock = m_verticalScrollbarLock = lock; }
113
114    virtual void setCanHaveScrollbars(bool);
115    bool canHaveScrollbars() const { return horizontalScrollbarMode() != ScrollbarAlwaysOff || verticalScrollbarMode() != ScrollbarAlwaysOff; }
116
117    virtual bool avoidScrollbarCreation() const { return false; }
118
119    // By default you only receive paint events for the area that is visible. In the case of using a
120    // tiled backing store, this function can be set, so that the view paints the entire contents.
121    bool paintsEntireContents() const { return m_paintsEntireContents; }
122    void setPaintsEntireContents(bool);
123
124    // By default, paint events are clipped to the visible area.  If set to
125    // false, paint events are no longer clipped.  paintsEntireContents() implies !clipsRepaints().
126    bool clipsRepaints() const { return m_clipsRepaints; }
127    void setClipsRepaints(bool);
128
129    // By default programmatic scrolling is handled by WebCore and not by the UI application.
130    // In the case of using a tiled backing store, this mode can be set, so that the scroll requests
131    // are delegated to the UI application.
132    bool delegatesScrolling() const { return m_delegatesScrolling; }
133    void setDelegatesScrolling(bool);
134
135    // Overridden by FrameView to create custom CSS scrollbars if applicable.
136    virtual PassRefPtr<Scrollbar> createScrollbar(ScrollbarOrientation);
137
138    // If the prohibits scrolling flag is set, then all scrolling in the view (even programmatic scrolling) is turned off.
139    void setProhibitsScrolling(bool b) { m_prohibitsScrolling = b; }
140    bool prohibitsScrolling() const { return m_prohibitsScrolling; }
141
142    // Whether or not a scroll view will blit visible contents when it is scrolled. Blitting is disabled in situations
143    // where it would cause rendering glitches (such as with fixed backgrounds or when the view is partially transparent).
144    void setCanBlitOnScroll(bool);
145    bool canBlitOnScroll() const;
146
147    // The visible content rect has a location that is the scrolled offset of the document. The width and height are the viewport width
148    // and height. By default the scrollbars themselves are excluded from this rectangle, but an optional boolean argument allows them to be
149    // included.
150    // In the situation the client is responsible for the scrolling (ie. with a tiled backing store) it is possible to use
151    // the actualVisibleContentRect instead, though this must be updated manually, e.g after panning ends.
152    IntRect visibleContentRect(bool includeScrollbars = false) const;
153    IntRect actualVisibleContentRect() const { return m_actualVisibleContentRect.isEmpty() ? visibleContentRect() : m_actualVisibleContentRect; }
154    void setActualVisibleContentRect(const IntRect& actualVisibleContentRect) { m_actualVisibleContentRect = actualVisibleContentRect; }
155    int visibleWidth() const { return visibleContentRect().width(); }
156    int visibleHeight() const { return visibleContentRect().height(); }
157
158    // Functions for getting/setting the size webkit should use to layout the contents. By default this is the same as the visible
159    // content size. Explicitly setting a layout size value will cause webkit to layout the contents using this size instead.
160    int layoutWidth() const;
161    int layoutHeight() const;
162    IntSize fixedLayoutSize() const;
163    void setFixedLayoutSize(const IntSize&);
164    bool useFixedLayout() const;
165    void setUseFixedLayout(bool enable);
166
167    // Functions for getting/setting the size of the document contained inside the ScrollView (as an IntSize or as individual width and height
168    // values).
169    IntSize contentsSize() const; // Always at least as big as the visibleWidth()/visibleHeight().
170    int contentsWidth() const { return contentsSize().width(); }
171    int contentsHeight() const { return contentsSize().height(); }
172    virtual void setContentsSize(const IntSize&);
173
174#if PLATFORM(ANDROID)
175    int actualWidth() const;
176    int actualHeight() const;
177    int actualScrollX() const;
178    int actualScrollY() const;
179    FrameView* frameView();
180#endif
181
182    // Functions for querying the current scrolled position (both as a point, a size, or as individual X and Y values).
183    IntPoint scrollPosition() const { return visibleContentRect().location(); }
184    IntSize scrollOffset() const { return visibleContentRect().location() - IntPoint(); } // Gets the scrolled position as an IntSize. Convenient for adding to other sizes.
185    IntPoint maximumScrollPosition() const; // The maximum position we can be scrolled to.
186    IntPoint minimumScrollPosition() const; // The minimum position we can be scrolled to.
187    // Adjust the passed in scroll position to keep it between the minimum and maximum positions.
188    IntPoint adjustScrollPositionWithinRange(const IntPoint&) const;
189    int scrollX() const { return scrollPosition().x(); }
190    int scrollY() const { return scrollPosition().y(); }
191
192    IntSize overhangAmount() const;
193
194    void cacheCurrentScrollPosition() { m_cachedScrollPosition = scrollPosition(); }
195    IntPoint cachedScrollPosition() const { return m_cachedScrollPosition; }
196
197    // Functions for scrolling the view.
198    void setScrollPosition(const IntPoint&);
199    void scrollBy(const IntSize& s) { return setScrollPosition(scrollPosition() + s); }
200
201    // This function scrolls by lines, pages or pixels.
202    bool scroll(ScrollDirection, ScrollGranularity);
203
204    // A logical scroll that just ends up calling the corresponding physical scroll() based off the document's writing mode.
205    bool logicalScroll(ScrollLogicalDirection, ScrollGranularity);
206
207    // Scroll the actual contents of the view (either blitting or invalidating as needed).
208    void scrollContents(const IntSize& scrollDelta);
209
210    // This gives us a means of blocking painting on our scrollbars until the first layout has occurred.
211    void setScrollbarsSuppressed(bool suppressed, bool repaintOnUnsuppress = false);
212    bool scrollbarsSuppressed() const { return m_scrollbarsSuppressed; }
213
214    // Event coordinates are assumed to be in the coordinate space of a window that contains
215    // the entire widget hierarchy. It is up to the platform to decide what the precise definition
216    // of containing window is. (For example on Mac it is the containing NSWindow.)
217    IntPoint windowToContents(const IntPoint&) const;
218    IntPoint contentsToWindow(const IntPoint&) const;
219    IntRect windowToContents(const IntRect&) const;
220    IntRect contentsToWindow(const IntRect&) const;
221
222    // Functions for converting to and from screen coordinates.
223    IntRect contentsToScreen(const IntRect&) const;
224    IntPoint screenToContents(const IntPoint&) const;
225
226    // The purpose of this function is to answer whether or not the scroll view is currently visible. Animations and painting updates can be suspended if
227    // we know that we are either not in a window right now or if that window is not visible.
228    bool isOffscreen() const;
229
230    // These functions are used to enable scrollbars to avoid window resizer controls that overlap the scroll view. This happens on Mac
231    // for example.
232    virtual IntRect windowResizerRect() const { return IntRect(); }
233    bool containsScrollbarsAvoidingResizer() const;
234    void adjustScrollbarsAvoidingResizerCount(int overlapDelta);
235    void windowResizerRectChanged();
236
237    virtual void setParent(ScrollView*); // Overridden to update the overlapping scrollbar count.
238
239    // Called when our frame rect changes (or the rect/scroll position of an ancestor changes).
240    virtual void frameRectsChanged();
241
242    // Widget override to update our scrollbars and notify our contents of the resize.
243    virtual void setFrameRect(const IntRect&);
244    virtual void setBoundsSize(const IntSize&);
245
246    // For platforms that need to hit test scrollbars from within the engine's event handlers (like Win32).
247    Scrollbar* scrollbarAtPoint(const IntPoint& windowPoint);
248
249    // This function exists for scrollviews that need to handle wheel events manually.
250    // On Mac the underlying NSScrollView just does the scrolling, but on other platforms
251    // (like Windows), we need this function in order to do the scroll ourselves.
252    void wheelEvent(PlatformWheelEvent&);
253#if ENABLE(GESTURE_EVENTS)
254    void gestureEvent(const PlatformGestureEvent&);
255#endif
256
257    IntPoint convertChildToSelf(const Widget* child, const IntPoint& point) const
258    {
259        IntPoint newPoint = point;
260        if (!isScrollViewScrollbar(child))
261            newPoint = point - scrollOffset();
262        newPoint.move(child->x(), child->y());
263        return newPoint;
264    }
265
266    IntPoint convertSelfToChild(const Widget* child, const IntPoint& point) const
267    {
268        IntPoint newPoint = point;
269        if (!isScrollViewScrollbar(child))
270            newPoint = point + scrollOffset();
271        newPoint.move(-child->x(), -child->y());
272        return newPoint;
273    }
274
275    // Widget override. Handles painting of the contents of the view as well as the scrollbars.
276    virtual void paint(GraphicsContext*, const IntRect&);
277    void paintScrollbars(GraphicsContext*, const IntRect&);
278
279    // Widget overrides to ensure that our children's visibility status is kept up to date when we get shown and hidden.
280    virtual void show();
281    virtual void hide();
282    virtual void setParentVisible(bool);
283
284    // Pan scrolling.
285    static const int noPanScrollRadius = 15;
286    void addPanScrollIcon(const IntPoint&);
287    void removePanScrollIcon();
288    void paintPanScrollIcon(GraphicsContext*);
289
290    virtual bool isPointInScrollbarCorner(const IntPoint&);
291    virtual bool scrollbarCornerPresent() const;
292    virtual IntRect scrollCornerRect() const;
293    virtual void paintScrollCorner(GraphicsContext*, const IntRect& cornerRect);
294
295    virtual IntRect convertFromScrollbarToContainingView(const Scrollbar*, const IntRect&) const;
296    virtual IntRect convertFromContainingViewToScrollbar(const Scrollbar*, const IntRect&) const;
297    virtual IntPoint convertFromScrollbarToContainingView(const Scrollbar*, const IntPoint&) const;
298    virtual IntPoint convertFromContainingViewToScrollbar(const Scrollbar*, const IntPoint&) const;
299
300    bool containsScrollableAreaWithOverlayScrollbars() const { return m_containsScrollableAreaWithOverlayScrollbars; }
301    void setContainsScrollableAreaWithOverlayScrollbars(bool contains) { m_containsScrollableAreaWithOverlayScrollbars = contains; }
302
303protected:
304    ScrollView();
305
306    virtual void repaintContentRectangle(const IntRect&, bool now = false);
307    virtual void paintContents(GraphicsContext*, const IntRect& damageRect) = 0;
308
309    void calculateOverhangAreasForPainting(IntRect& horizontalOverhangRect, IntRect& verticalOverhangRect);
310    virtual void paintOverhangAreas(GraphicsContext*, const IntRect& horizontalOverhangArea, const IntRect& verticalOverhangArea, const IntRect& dirtyRect);
311
312    virtual void contentsResized() = 0;
313    virtual void visibleContentsResized() = 0;
314
315    IntSize boundsSize() const { return m_boundsSize; }
316    void setInitialBoundsSize(const IntSize&);
317
318    // These functions are used to create/destroy scrollbars.
319    void setHasHorizontalScrollbar(bool);
320    void setHasVerticalScrollbar(bool);
321
322    virtual void updateScrollCorner();
323    virtual void invalidateScrollCornerRect(const IntRect&);
324
325    // Scroll the content by blitting the pixels.
326    virtual bool scrollContentsFastPath(const IntSize& scrollDelta, const IntRect& rectToScroll, const IntRect& clipRect);
327    // Scroll the content by invalidating everything.
328    virtual void scrollContentsSlowPath(const IntRect& updateRect);
329
330    void setScrollOrigin(const IntPoint&, bool updatePositionAtAll, bool updatePositionSynchronously);
331    IntPoint scrollOrigin() { return m_scrollOrigin; }
332
333    // Subclassed by FrameView to check the writing-mode of the document.
334    virtual bool isVerticalDocument() const { return true; }
335    virtual bool isFlippedDocument() const { return false; }
336
337private:
338    RefPtr<Scrollbar> m_horizontalScrollbar;
339    RefPtr<Scrollbar> m_verticalScrollbar;
340    ScrollbarMode m_horizontalScrollbarMode;
341    ScrollbarMode m_verticalScrollbarMode;
342
343    bool m_horizontalScrollbarLock;
344    bool m_verticalScrollbarLock;
345
346    bool m_prohibitsScrolling;
347
348    HashSet<RefPtr<Widget> > m_children;
349
350    // This bool is unused on Mac OS because we directly ask the platform widget
351    // whether it is safe to blit on scroll.
352    bool m_canBlitOnScroll;
353
354    IntRect m_actualVisibleContentRect;
355    IntSize m_scrollOffset; // FIXME: Would rather store this as a position, but we will wait to make this change until more code is shared.
356    IntPoint m_cachedScrollPosition;
357    IntSize m_fixedLayoutSize;
358    IntSize m_contentsSize;
359
360    int m_scrollbarsAvoidingResizer;
361    bool m_scrollbarsSuppressed;
362
363    bool m_inUpdateScrollbars;
364    unsigned m_updateScrollbarsPass;
365
366    IntPoint m_panScrollIconPoint;
367    bool m_drawPanScrollIcon;
368    bool m_useFixedLayout;
369
370    bool m_paintsEntireContents;
371    bool m_clipsRepaints;
372    bool m_delegatesScrolling;
373
374    bool m_containsScrollableAreaWithOverlayScrollbars;
375
376    IntSize m_boundsSize;
377
378    void init();
379    void destroy();
380
381    // Called to update the scrollbars to accurately reflect the state of the view.
382    void updateScrollbars(const IntSize& desiredOffset);
383
384    // Called when the scroll position within this view changes.  FrameView overrides this to generate repaint invalidations.
385    virtual void repaintFixedElementsAfterScrolling() {}
386
387    void platformInit();
388    void platformDestroy();
389    void platformAddChild(Widget*);
390    void platformRemoveChild(Widget*);
391    void platformSetScrollbarModes();
392    void platformScrollbarModes(ScrollbarMode& horizontal, ScrollbarMode& vertical) const;
393    void platformSetCanBlitOnScroll(bool);
394    bool platformCanBlitOnScroll() const;
395    IntRect platformVisibleContentRect(bool includeScrollbars) const;
396    IntSize platformContentsSize() const;
397    void platformSetContentsSize();
398    IntRect platformContentsToScreen(const IntRect&) const;
399    IntPoint platformScreenToContents(const IntPoint&) const;
400    void platformSetScrollPosition(const IntPoint&);
401    bool platformScroll(ScrollDirection, ScrollGranularity);
402    void platformSetScrollbarsSuppressed(bool repaintOnUnsuppress);
403    void platformRepaintContentRectangle(const IntRect&, bool now);
404    bool platformIsOffscreen() const;
405
406    void platformSetScrollOrigin(const IntPoint&, bool updatePositionAtAll, bool updatePositionSynchronously);
407
408#if PLATFORM(ANDROID)
409    int platformActualWidth() const;
410    int platformActualHeight() const;
411    int platformActualScrollX() const;
412    int platformActualScrollY() const;
413#endif
414
415#if PLATFORM(MAC) && defined __OBJC__
416public:
417    NSView* documentView() const;
418
419private:
420    NSScrollView<WebCoreFrameScrollView>* scrollView() const;
421#endif
422
423#if PLATFORM(GTK)
424public:
425    void setGtkAdjustments(GtkAdjustment* hadj, GtkAdjustment* vadj, bool resetValues = true);
426    void setHorizontalAdjustment(GtkAdjustment* hadj, bool resetValues = true);
427    void setVerticalAdjustment(GtkAdjustment* vadj, bool resetValues = true);
428    void setScrollOffset(const IntSize& offset) { m_scrollOffset = offset; }
429
430private:
431    GRefPtr<GtkAdjustment> m_horizontalAdjustment;
432    GRefPtr<GtkAdjustment> m_verticalAdjustment;
433#endif
434
435#if PLATFORM(WX)
436public:
437    virtual void setPlatformWidget(wxWindow*);
438    void adjustScrollbars(int x = -1, int y = -1, bool refresh = true);
439private:
440    class ScrollViewPrivate;
441    ScrollViewPrivate* m_data;
442#endif
443
444#ifdef ANDROID_CAPTURE_OFFSCREEN_PAINTS
445public:
446    // capture parts of rect not contained by vis
447    void platformOffscreenContentRectangle(const IntRect& vis,
448        const IntRect& rect);
449#endif
450}; // class ScrollView
451
452} // namespace WebCore
453
454#endif // ScrollView_h
455