1/*
2 * Copyright (C) 2004-2018 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 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 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#pragma once
28
29#include "FloatRect.h"
30#include "IntRect.h"
31#include "Scrollbar.h"
32#include "ScrollableArea.h"
33#include "ScrollTypes.h"
34#include "Widget.h"
35#include <wtf/HashSet.h>
36#include <wtf/WeakPtr.h>
37
38#if PLATFORM(IOS_FAMILY)
39
40OBJC_CLASS WAKScrollView;
41OBJC_CLASS WAKView;
42
43#ifndef NSScrollView
44#define NSScrollView WAKScrollView
45#endif
46
47#ifndef NSView
48#define NSView WAKView
49#endif
50
51#endif // PLATFORM(IOS_FAMILY)
52
53#if PLATFORM(COCOA) && defined __OBJC__
54@class NSScrollView;
55@protocol WebCoreFrameScrollView;
56#endif
57
58namespace WebCore {
59
60class HostWindow;
61class LegacyTileCache;
62class Scrollbar;
63
64class ScrollView : public Widget, public ScrollableArea {
65public:
66 virtual ~ScrollView();
67
68 // ScrollableArea functions.
69 int scrollSize(ScrollbarOrientation) const final;
70 int scrollOffset(ScrollbarOrientation) const final;
71 WEBCORE_EXPORT void setScrollOffset(const ScrollOffset&) final;
72 bool isScrollCornerVisible() const final;
73 void scrollbarStyleChanged(ScrollbarStyle, bool forceUpdate) override;
74
75 virtual void notifyPageThatContentAreaWillPaint() const;
76
77 using Widget::weakPtrFactory;
78
79 IntPoint locationOfContents() const;
80
81 // NOTE: This should only be called by the overridden setScrollOffset from ScrollableArea.
82 virtual void scrollTo(const ScrollPosition&);
83
84 // The window thats hosts the ScrollView. The ScrollView will communicate scrolls and repaints to the
85 // host window in the window's coordinate space.
86 virtual HostWindow* hostWindow() const = 0;
87
88 // Returns a clip rect in host window coordinates. Used to clip the blit on a scroll.
89 virtual IntRect windowClipRect() const = 0;
90
91 // Functions for child manipulation and inspection.
92 const HashSet<Ref<Widget>>& children() const { return m_children; }
93 WEBCORE_EXPORT virtual void addChild(Widget&);
94 WEBCORE_EXPORT virtual void removeChild(Widget&);
95
96 // If the scroll view does not use a native widget, then it will have cross-platform Scrollbars. These functions
97 // can be used to obtain those scrollbars.
98 Scrollbar* horizontalScrollbar() const final { return m_horizontalScrollbar.get(); }
99 Scrollbar* verticalScrollbar() const final { return m_verticalScrollbar.get(); }
100 bool isScrollViewScrollbar(const Widget* child) const { return horizontalScrollbar() == child || verticalScrollbar() == child; }
101
102 void positionScrollbarLayers();
103
104 // Functions for setting and retrieving the scrolling mode in each axis (horizontal/vertical). The mode has values of
105 // AlwaysOff, AlwaysOn, and Auto. AlwaysOff means never show a scrollbar, AlwaysOn means always show a scrollbar.
106 // Auto means show a scrollbar only when one is needed.
107 // Note that for platforms with native widgets, these modes are considered advisory. In other words the underlying native
108 // widget may choose not to honor the requested modes.
109 WEBCORE_EXPORT void setScrollbarModes(ScrollbarMode horizontalMode, ScrollbarMode verticalMode, bool horizontalLock = false, bool verticalLock = false);
110 void setHorizontalScrollbarMode(ScrollbarMode mode, bool lock = false) { setScrollbarModes(mode, verticalScrollbarMode(), lock, verticalScrollbarLock()); }
111 void setVerticalScrollbarMode(ScrollbarMode mode, bool lock = false) { setScrollbarModes(horizontalScrollbarMode(), mode, horizontalScrollbarLock(), lock); };
112 WEBCORE_EXPORT void scrollbarModes(ScrollbarMode& horizontalMode, ScrollbarMode& verticalMode) const;
113 ScrollbarMode horizontalScrollbarMode() const final { ScrollbarMode horizontal, vertical; scrollbarModes(horizontal, vertical); return horizontal; }
114 ScrollbarMode verticalScrollbarMode() const final { ScrollbarMode horizontal, vertical; scrollbarModes(horizontal, vertical); return vertical; }
115
116 void setHorizontalScrollbarLock(bool lock = true) { m_horizontalScrollbarLock = lock; }
117 bool horizontalScrollbarLock() const { return m_horizontalScrollbarLock; }
118 void setVerticalScrollbarLock(bool lock = true) { m_verticalScrollbarLock = lock; }
119 bool verticalScrollbarLock() const { return m_verticalScrollbarLock; }
120
121 void setScrollingModesLock(bool lock = true) { m_horizontalScrollbarLock = m_verticalScrollbarLock = lock; }
122
123 WEBCORE_EXPORT virtual void setCanHaveScrollbars(bool);
124 bool canHaveScrollbars() const { return horizontalScrollbarMode() != ScrollbarAlwaysOff || verticalScrollbarMode() != ScrollbarAlwaysOff; }
125
126 virtual bool avoidScrollbarCreation() const { return false; }
127
128 void setScrollbarOverlayStyle(ScrollbarOverlayStyle) final;
129
130 // By default you only receive paint events for the area that is visible. In the case of using a
131 // tiled backing store, this function can be set, so that the view paints the entire contents.
132 bool paintsEntireContents() const { return m_paintsEntireContents; }
133 WEBCORE_EXPORT void setPaintsEntireContents(bool);
134
135 // By default programmatic scrolling is handled by WebCore and not by the UI application.
136 // In the case of using a tiled backing store, this mode can be set, so that the scroll requests
137 // are delegated to the UI application.
138 bool delegatesScrolling() const { return m_delegatesScrolling; }
139 WEBCORE_EXPORT void setDelegatesScrolling(bool);
140
141 // Overridden by FrameView to create custom CSS scrollbars if applicable.
142 virtual Ref<Scrollbar> createScrollbar(ScrollbarOrientation);
143
144 void styleDidChange();
145
146 // If the prohibits scrolling flag is set, then all scrolling in the view (even programmatic scrolling) is turned off.
147 void setProhibitsScrolling(bool b) { m_prohibitsScrolling = b; }
148 bool prohibitsScrolling() const { return m_prohibitsScrolling; }
149
150 // Whether or not a scroll view will blit visible contents when it is scrolled. Blitting is disabled in situations
151 // where it would cause rendering glitches (such as with fixed backgrounds or when the view is partially transparent).
152 void setCanBlitOnScroll(bool);
153 bool canBlitOnScroll() const;
154
155 // There are at least three types of contentInset. Usually we just care about WebCoreContentInset, which is the inset
156 // that is set on a Page that requires WebCore to move its layers to accomodate the inset. However, there are platform
157 // concepts that are similar on both iOS and Mac when there is a platformWidget(). Sometimes we need the Mac platform value
158 // for topContentInset, so when the TopContentInsetType is WebCoreOrPlatformContentInset, platformTopContentInset()
159 // will be returned instead of the value set on Page.
160 enum class TopContentInsetType { WebCoreContentInset, WebCoreOrPlatformContentInset };
161 virtual float topContentInset(TopContentInsetType = TopContentInsetType::WebCoreContentInset) const { return 0; }
162
163 // The visible content rect has a location that is the scrolled offset of the document. The width and height are the unobscured viewport
164 // width and height. By default the scrollbars themselves are excluded from this rectangle, but an optional boolean argument allows them
165 // to be included.
166 // In the situation the client is responsible for the scrolling (ie. with a tiled backing store) it is possible to use
167 // the setFixedVisibleContentRect instead for the mainframe, though this must be updated manually, e.g just before resuming the page
168 // which usually will happen when panning, pinching and rotation ends, or when scale or position are changed manually.
169 IntSize visibleSize() const final { return visibleContentRect(LegacyIOSDocumentVisibleRect).size(); }
170
171#if USE(COORDINATED_GRAPHICS)
172 virtual void setFixedVisibleContentRect(const IntRect& visibleContentRect) { m_fixedVisibleContentRect = visibleContentRect; }
173 IntRect fixedVisibleContentRect() const { return m_fixedVisibleContentRect; }
174#endif
175
176 // Parts of the document can be visible through transparent or blured UI widgets of the chrome. Those parts
177 // contribute to painting but not to the scrollable area.
178 // The unobscuredContentRect is the area that is not covered by UI elements.
179 WEBCORE_EXPORT IntRect unobscuredContentRect(VisibleContentRectIncludesScrollbars = ExcludeScrollbars) const;
180#if PLATFORM(IOS_FAMILY)
181 IntRect unobscuredContentRectIncludingScrollbars() const { return unobscuredContentRect(IncludeScrollbars); }
182#else
183 IntRect unobscuredContentRectIncludingScrollbars() const { return visibleContentRectIncludingScrollbars(); }
184#endif
185
186#if PLATFORM(IOS_FAMILY)
187 // This is the area that is partially or fully exposed, and may extend under overlapping UI elements.
188 WEBCORE_EXPORT FloatRect exposedContentRect() const;
189
190 // The given rects are only used if there is no platform widget.
191 WEBCORE_EXPORT void setExposedContentRect(const FloatRect&);
192 const FloatSize& unobscuredContentSize() const { return m_unobscuredContentSize; }
193 WEBCORE_EXPORT void setUnobscuredContentSize(const FloatSize&);
194
195 void setActualScrollPosition(const IntPoint&);
196 LegacyTileCache* legacyTileCache();
197#endif
198
199 // Size available for view contents, including content inset areas. Not affected by zooming.
200 IntSize sizeForVisibleContent(VisibleContentRectIncludesScrollbars = ExcludeScrollbars) const;
201 // FIXME: remove this. It's only used for the incorrectly behaving ScrollView::unobscuredContentRectInternal().
202 virtual float visibleContentScaleFactor() const { return 1; }
203
204 // Functions for getting/setting the size webkit should use to layout the contents. By default this is the same as the visible
205 // content size. Explicitly setting a layout size value will cause webkit to layout the contents using this size instead.
206 WEBCORE_EXPORT IntSize layoutSize() const;
207 int layoutWidth() const { return layoutSize().width(); }
208 int layoutHeight() const { return layoutSize().height(); }
209
210 WEBCORE_EXPORT IntSize fixedLayoutSize() const;
211 WEBCORE_EXPORT void setFixedLayoutSize(const IntSize&);
212 WEBCORE_EXPORT bool useFixedLayout() const;
213 WEBCORE_EXPORT void setUseFixedLayout(bool enable);
214
215 // Functions for getting/setting the size of the document contained inside the ScrollView (as an IntSize or as individual width and height
216 // values).
217 WEBCORE_EXPORT IntSize contentsSize() const final; // Always at least as big as the visibleWidth()/visibleHeight().
218 int contentsWidth() const { return contentsSize().width(); }
219 int contentsHeight() const { return contentsSize().height(); }
220 virtual void setContentsSize(const IntSize&);
221
222 // Functions for querying the current scrolled position (both as a point, a size, or as individual X and Y values).
223 ScrollPosition scrollPosition() const final { return visibleContentRect(LegacyIOSDocumentVisibleRect).location(); }
224
225 ScrollPosition maximumScrollPosition() const override; // The maximum position we can be scrolled to.
226
227 // Adjust the passed in scroll position to keep it between the minimum and maximum positions.
228 ScrollPosition adjustScrollPositionWithinRange(const ScrollPosition&) const;
229 int scrollX() const { return scrollPosition().x(); }
230 int scrollY() const { return scrollPosition().y(); }
231
232 // Scroll position used by web-exposed features (has legacy iOS behavior).
233 WEBCORE_EXPORT IntPoint contentsScrollPosition() const;
234 void setContentsScrollPosition(const IntPoint&);
235
236#if PLATFORM(IOS_FAMILY)
237 int actualScrollX() const { return unobscuredContentRect().x(); }
238 int actualScrollY() const { return unobscuredContentRect().y(); }
239 // FIXME: maybe fix scrollPosition() on iOS to return the actual scroll position.
240 IntPoint actualScrollPosition() const { return unobscuredContentRect().location(); }
241#endif
242
243 // scrollOffset() anchors its (0,0) point at the ScrollableArea's origin. When the Page has a
244 // header, the header is positioned at (0,0), ABOVE the start of the Document. So when a page with
245 // a header is pinned to the top, the scrollOffset() is (0,0), but the Document is actually at
246 // (0, -headerHeight()). documentScrollPositionRelativeToScrollableAreaOrigin() will return this
247 // version of the offset, which tracks the top of Document relative to where scrolling was achored.
248 ScrollPosition documentScrollPositionRelativeToScrollableAreaOrigin() const;
249
250 // scrollPostion() anchors its (0,0) point at the ScrollableArea's origin. The top of the scrolling
251 // layer does not represent the top of the view when there is a topContentInset. Additionally, as
252 // detailed above, the origin of the scrolling layer also does not necessarily correspond with the
253 // top of the document anyway, since there could also be header. documentScrollPositionRelativeToViewOrigin()
254 // will return a version of the current scroll offset which tracks the top of the Document
255 // relative to the very top of the view.
256 WEBCORE_EXPORT ScrollPosition documentScrollPositionRelativeToViewOrigin() const;
257
258 IntSize overhangAmount() const final;
259
260 void cacheCurrentScrollPosition() { m_cachedScrollPosition = scrollPosition(); }
261 ScrollPosition cachedScrollPosition() const { return m_cachedScrollPosition; }
262
263 // Functions for scrolling the view.
264 virtual void setScrollPosition(const ScrollPosition&);
265 void scrollBy(const IntSize& s) { return setScrollPosition(scrollPosition() + s); }
266
267 // This function scrolls by lines, pages or pixels.
268 bool scroll(ScrollDirection, ScrollGranularity);
269
270 // A logical scroll that just ends up calling the corresponding physical scroll() based off the document's writing mode.
271 bool logicalScroll(ScrollLogicalDirection, ScrollGranularity);
272
273 // Scroll the actual contents of the view (either blitting or invalidating as needed).
274 void scrollContents(const IntSize& scrollDelta);
275
276 // This gives us a means of blocking painting on our scrollbars until the first layout has occurred.
277 WEBCORE_EXPORT void setScrollbarsSuppressed(bool suppressed, bool repaintOnUnsuppress = false);
278 bool scrollbarsSuppressed() const { return m_scrollbarsSuppressed; }
279
280 WEBCORE_EXPORT IntPoint rootViewToContents(const IntPoint&) const;
281 WEBCORE_EXPORT IntPoint contentsToRootView(const IntPoint&) const;
282 WEBCORE_EXPORT FloatPoint contentsToRootView(const FloatPoint&) const;
283 WEBCORE_EXPORT IntRect rootViewToContents(const IntRect&) const;
284 WEBCORE_EXPORT IntRect contentsToRootView(const IntRect&) const;
285 WEBCORE_EXPORT FloatRect rootViewToContents(const FloatRect&) const;
286 WEBCORE_EXPORT FloatRect contentsToRootView(const FloatRect&) const;
287
288 IntPoint viewToContents(const IntPoint&) const;
289 IntPoint contentsToView(const IntPoint&) const;
290
291 FloatPoint viewToContents(const FloatPoint&) const;
292 FloatPoint contentsToView(const FloatPoint&) const;
293
294 IntRect viewToContents(IntRect) const;
295 IntRect contentsToView(IntRect) const;
296
297 FloatRect viewToContents(FloatRect) const;
298 FloatRect contentsToView(FloatRect) const;
299
300 IntPoint contentsToContainingViewContents(const IntPoint&) const;
301 IntRect contentsToContainingViewContents(IntRect) const;
302
303 WEBCORE_EXPORT IntPoint rootViewToTotalContents(const IntPoint&) const;
304
305 // Event coordinates are assumed to be in the coordinate space of a window that contains
306 // the entire widget hierarchy. It is up to the platform to decide what the precise definition
307 // of containing window is. (For example on Mac it is the containing NSWindow.)
308 WEBCORE_EXPORT IntPoint windowToContents(const IntPoint&) const;
309 WEBCORE_EXPORT IntPoint contentsToWindow(const IntPoint&) const;
310 WEBCORE_EXPORT IntRect windowToContents(const IntRect&) const;
311 WEBCORE_EXPORT IntRect contentsToWindow(const IntRect&) const;
312
313 // Functions for converting to and from screen coordinates.
314 WEBCORE_EXPORT IntRect contentsToScreen(const IntRect&) const;
315 IntPoint screenToContents(const IntPoint&) const;
316
317 // 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
318 // we know that we are either not in a window right now or if that window is not visible.
319 bool isOffscreen() const;
320
321 // Called when our frame rect changes (or the rect/scroll position of an ancestor changes).
322 void frameRectsChanged() final;
323
324 // Widget override to update our scrollbars and notify our contents of the resize.
325 void setFrameRect(const IntRect&) override;
326
327 // Widget override to notify our contents of a cliprect change.
328 void clipRectChanged() final;
329
330 // For platforms that need to hit test scrollbars from within the engine's event handlers (like Win32).
331 Scrollbar* scrollbarAtPoint(const IntPoint& windowPoint);
332
333 IntPoint convertChildToSelf(const Widget* child, const IntPoint& point) const
334 {
335 IntPoint newPoint = point;
336 if (!isScrollViewScrollbar(child))
337 newPoint = point - toIntSize(scrollPosition());
338 newPoint.moveBy(child->location());
339 return newPoint;
340 }
341
342 IntPoint convertSelfToChild(const Widget* child, const IntPoint& point) const
343 {
344 IntPoint newPoint = point;
345 if (!isScrollViewScrollbar(child))
346 newPoint = point + toIntSize(scrollPosition());
347 newPoint.moveBy(-child->location());
348 return newPoint;
349 }
350
351 // Widget override. Handles painting of the contents of the view as well as the scrollbars.
352 WEBCORE_EXPORT void paint(GraphicsContext&, const IntRect&, Widget::SecurityOriginPaintPolicy = SecurityOriginPaintPolicy::AnyOrigin) final;
353 void paintScrollbars(GraphicsContext&, const IntRect&);
354
355 // Widget overrides to ensure that our children's visibility status is kept up to date when we get shown and hidden.
356 WEBCORE_EXPORT void show() override;
357 WEBCORE_EXPORT void hide() override;
358 WEBCORE_EXPORT void setParentVisible(bool) final;
359
360 // Pan scrolling.
361 static const int noPanScrollRadius = 15;
362 void addPanScrollIcon(const IntPoint&);
363 void removePanScrollIcon();
364 void paintPanScrollIcon(GraphicsContext&);
365
366 bool isPointInScrollbarCorner(const IntPoint&);
367 bool scrollbarCornerPresent() const;
368 IntRect scrollCornerRect() const final;
369 virtual void paintScrollCorner(GraphicsContext&, const IntRect& cornerRect);
370 virtual void paintScrollbar(GraphicsContext&, Scrollbar&, const IntRect&);
371
372 IntRect convertFromScrollbarToContainingView(const Scrollbar&, const IntRect&) const final;
373 IntRect convertFromContainingViewToScrollbar(const Scrollbar&, const IntRect&) const final;
374 IntPoint convertFromScrollbarToContainingView(const Scrollbar&, const IntPoint&) const final;
375 IntPoint convertFromContainingViewToScrollbar(const Scrollbar&, const IntPoint&) const final;
376
377 void calculateAndPaintOverhangAreas(GraphicsContext&, const IntRect& dirtyRect);
378
379 WEBCORE_EXPORT void scrollOffsetChangedViaPlatformWidget(const ScrollOffset& oldOffset, const ScrollOffset& newOffset);
380
381 void setAllowsUnclampedScrollPositionForTesting(bool allowsUnclampedScrollPosition) { m_allowsUnclampedScrollPosition = allowsUnclampedScrollPosition; }
382 bool allowsUnclampedScrollPosition() const { return m_allowsUnclampedScrollPosition; }
383
384 bool managesScrollbars() const;
385
386protected:
387 ScrollView();
388
389 virtual void repaintContentRectangle(const IntRect&);
390 virtual void paintContents(GraphicsContext&, const IntRect& damageRect, SecurityOriginPaintPolicy = SecurityOriginPaintPolicy::AnyOrigin) = 0;
391
392 virtual void paintOverhangAreas(GraphicsContext&, const IntRect& horizontalOverhangArea, const IntRect& verticalOverhangArea, const IntRect& dirtyRect);
393
394 void availableContentSizeChanged(AvailableSizeChangeReason) override;
395 virtual void addedOrRemovedScrollbar() = 0;
396 virtual void delegatesScrollingDidChange() = 0;
397
398 // These functions are used to create/destroy scrollbars.
399 // They return true if the scrollbar was added or removed.
400 bool setHasHorizontalScrollbar(bool, bool* contentSizeAffected = nullptr);
401 bool setHasVerticalScrollbar(bool, bool* contentSizeAffected = nullptr);
402
403 virtual void updateScrollCorner() = 0;
404 void invalidateScrollCornerRect(const IntRect&) final;
405
406 // Scroll the content by blitting the pixels.
407 virtual bool scrollContentsFastPath(const IntSize& scrollDelta, const IntRect& rectToScroll, const IntRect& clipRect) = 0;
408 // Scroll the content by invalidating everything.
409 virtual void scrollContentsSlowPath(const IntRect& updateRect);
410
411 void setScrollOrigin(const IntPoint&, bool updatePositionAtAll, bool updatePositionSynchronously);
412
413 // Subclassed by FrameView to check the writing-mode of the document.
414 virtual bool isVerticalDocument() const = 0;
415 virtual bool isFlippedDocument() const = 0;
416
417 // Called to update the scrollbars to accurately reflect the state of the view.
418 void updateScrollbars(const ScrollPosition& desiredPosition);
419
420 float platformTopContentInset() const;
421 void platformSetTopContentInset(float);
422
423 void handleDeferredScrollUpdateAfterContentSizeChange();
424
425 virtual bool shouldDeferScrollUpdateAfterContentSizeChange() = 0;
426
427 virtual void scrollOffsetChangedViaPlatformWidgetImpl(const ScrollOffset&, const ScrollOffset&) = 0;
428
429#if PLATFORM(IOS_FAMILY)
430 virtual void unobscuredContentSizeChanged() = 0;
431#endif
432
433#if PLATFORM(COCOA) && defined __OBJC__
434public:
435 WEBCORE_EXPORT NSView* documentView() const;
436
437private:
438 NSScrollView<WebCoreFrameScrollView>* scrollView() const;
439#endif
440
441private:
442 // Size available for view contents, excluding content insets. Not affected by zooming.
443 IntSize sizeForUnobscuredContent(VisibleContentRectIncludesScrollbars = ExcludeScrollbars) const;
444
445 IntRect visibleContentRectInternal(VisibleContentRectIncludesScrollbars, VisibleContentRectBehavior) const final;
446 WEBCORE_EXPORT IntRect unobscuredContentRectInternal(VisibleContentRectIncludesScrollbars = ExcludeScrollbars) const;
447
448 void completeUpdatesAfterScrollTo(const IntSize& scrollDelta);
449
450 bool setHasScrollbarInternal(RefPtr<Scrollbar>&, ScrollbarOrientation, bool hasBar, bool* contentSizeAffected);
451
452 bool isScrollView() const final { return true; }
453
454 void init();
455 void destroy();
456
457 IntRect rectToCopyOnScroll() const;
458
459 // Called when the scroll position within this view changes. FrameView overrides this to generate repaint invalidations.
460 virtual void updateLayerPositionsAfterScrolling() = 0;
461 virtual void updateCompositingLayersAfterScrolling() = 0;
462
463 void platformAddChild(Widget*);
464 void platformRemoveChild(Widget*);
465 void platformSetScrollbarModes();
466 void platformScrollbarModes(ScrollbarMode& horizontal, ScrollbarMode& vertical) const;
467 void platformSetCanBlitOnScroll(bool);
468 bool platformCanBlitOnScroll() const;
469 IntRect platformVisibleContentRect(bool includeScrollbars) const;
470 IntSize platformVisibleContentSize(bool includeScrollbars) const;
471 IntRect platformVisibleContentRectIncludingObscuredArea(bool includeScrollbars) const;
472 IntSize platformVisibleContentSizeIncludingObscuredArea(bool includeScrollbars) const;
473 void platformSetContentsSize();
474 IntRect platformContentsToScreen(const IntRect&) const;
475 IntPoint platformScreenToContents(const IntPoint&) const;
476 void platformSetScrollPosition(const IntPoint&);
477 bool platformScroll(ScrollDirection, ScrollGranularity);
478 void platformSetScrollbarsSuppressed(bool repaintOnUnsuppress);
479 void platformRepaintContentRectangle(const IntRect&);
480 bool platformIsOffscreen() const;
481 void platformSetScrollbarOverlayStyle(ScrollbarOverlayStyle);
482 void platformSetScrollOrigin(const IntPoint&, bool updatePositionAtAll, bool updatePositionSynchronously);
483
484 void calculateOverhangAreasForPainting(IntRect& horizontalOverhangRect, IntRect& verticalOverhangRect);
485 void updateOverhangAreas();
486
487 HashSet<Ref<Widget>> m_children;
488
489 RefPtr<Scrollbar> m_horizontalScrollbar;
490 RefPtr<Scrollbar> m_verticalScrollbar;
491 ScrollbarMode m_horizontalScrollbarMode { ScrollbarAuto };
492 ScrollbarMode m_verticalScrollbarMode { ScrollbarAuto };
493
494#if PLATFORM(IOS_FAMILY)
495 // FIXME: exposedContentRect is a very similar concept to fixedVisibleContentRect except it does not differentiate
496 // between exposed and unobscured areas. The two attributes should eventually be merged.
497 FloatRect m_exposedContentRect;
498 FloatSize m_unobscuredContentSize;
499 // This is only used for history scroll position restoration.
500#else
501 IntRect m_fixedVisibleContentRect;
502#endif
503 ScrollPosition m_scrollPosition;
504 IntPoint m_cachedScrollPosition;
505 IntSize m_fixedLayoutSize;
506 IntSize m_contentsSize;
507
508 Optional<IntSize> m_deferredScrollDelta; // Needed for WebKit scrolling
509 Optional<std::pair<ScrollOffset, ScrollOffset>> m_deferredScrollOffsets; // Needed for platform widget scrolling
510
511 IntPoint m_panScrollIconPoint;
512
513 unsigned m_updateScrollbarsPass { 0 };
514
515 bool m_horizontalScrollbarLock { false };
516 bool m_verticalScrollbarLock { false };
517
518 bool m_prohibitsScrolling { false };
519 bool m_allowsUnclampedScrollPosition { false };
520
521 // This bool is unused on Mac OS because we directly ask the platform widget
522 // whether it is safe to blit on scroll.
523 bool m_canBlitOnScroll { true };
524
525 bool m_scrollbarsSuppressed { false };
526 bool m_inUpdateScrollbars { false };
527
528 bool m_drawPanScrollIcon { false };
529 bool m_useFixedLayout { false };
530
531 bool m_paintsEntireContents { false };
532 bool m_delegatesScrolling { false };
533}; // class ScrollView
534
535} // namespace WebCore
536
537SPECIALIZE_TYPE_TRAITS_WIDGET(ScrollView, isScrollView())
538