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