1/*
2 * Copyright (C) 2004, 2006, 2008, 2015 Apple Inc. All rights reserved.
3 *
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions
6 * are met:
7 * 1. Redistributions of source code must retain the above copyright
8 * notice, this list of conditions and the following disclaimer.
9 * 2. Redistributions in binary form must reproduce the above copyright
10 * notice, this list of conditions and the following disclaimer in the
11 * documentation and/or other materials provided with the distribution.
12 *
13 * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
14 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
15 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
16 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR
17 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
18 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
19 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
20 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
21 * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
22 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
23 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
24 */
25
26#include "config.h"
27#include "Scrollbar.h"
28
29#include "FrameView.h"
30#include "GraphicsContext.h"
31#include "PlatformMouseEvent.h"
32#include "ScrollAnimator.h"
33#include "ScrollView.h"
34#include "ScrollableArea.h"
35#include "ScrollbarTheme.h"
36#include <algorithm>
37
38#if PLATFORM(GTK)
39// The position of the scrollbar thumb affects the appearance of the steppers, so
40// when the thumb moves, we have to invalidate them for painting.
41#define THUMB_POSITION_AFFECTS_BUTTONS
42#endif
43
44namespace WebCore {
45
46Ref<Scrollbar> Scrollbar::createNativeScrollbar(ScrollableArea& scrollableArea, ScrollbarOrientation orientation, ScrollbarControlSize size)
47{
48 return adoptRef(*new Scrollbar(scrollableArea, orientation, size));
49}
50
51int Scrollbar::maxOverlapBetweenPages()
52{
53 static int maxOverlapBetweenPages = ScrollbarTheme::theme().maxOverlapBetweenPages();
54 return maxOverlapBetweenPages;
55}
56
57Scrollbar::Scrollbar(ScrollableArea& scrollableArea, ScrollbarOrientation orientation, ScrollbarControlSize controlSize, ScrollbarTheme* customTheme)
58 : m_scrollableArea(scrollableArea)
59 , m_orientation(orientation)
60 , m_controlSize(controlSize)
61 , m_theme(customTheme ? *customTheme : ScrollbarTheme::theme())
62 , m_scrollTimer(*this, &Scrollbar::autoscrollTimerFired)
63{
64 theme().registerScrollbar(*this);
65
66 // FIXME: This is ugly and would not be necessary if we fix cross-platform code to actually query for
67 // scrollbar thickness and use it when sizing scrollbars (rather than leaving one dimension of the scrollbar
68 // alone when sizing).
69 int thickness = theme().scrollbarThickness(controlSize);
70 Widget::setFrameRect(IntRect(0, 0, thickness, thickness));
71
72 m_currentPos = static_cast<float>(m_scrollableArea.scrollOffset(m_orientation));
73}
74
75Scrollbar::~Scrollbar()
76{
77 stopTimerIfNeeded();
78
79 theme().unregisterScrollbar(*this);
80}
81
82int Scrollbar::occupiedWidth() const
83{
84 return isOverlayScrollbar() ? 0 : width();
85}
86
87int Scrollbar::occupiedHeight() const
88{
89 return isOverlayScrollbar() ? 0 : height();
90}
91
92void Scrollbar::offsetDidChange()
93{
94 float position = static_cast<float>(m_scrollableArea.scrollOffset(m_orientation));
95 if (position == m_currentPos)
96 return;
97
98 int oldThumbPosition = theme().thumbPosition(*this);
99 m_currentPos = position;
100 updateThumbPosition();
101 if (m_pressedPart == ThumbPart)
102 setPressedPos(m_pressedPos + theme().thumbPosition(*this) - oldThumbPosition);
103}
104
105void Scrollbar::setProportion(int visibleSize, int totalSize)
106{
107 if (visibleSize == m_visibleSize && totalSize == m_totalSize)
108 return;
109
110 m_visibleSize = visibleSize;
111 m_totalSize = totalSize;
112
113 updateThumbProportion();
114}
115
116void Scrollbar::setSteps(int lineStep, int pageStep, int pixelsPerStep)
117{
118 m_lineStep = lineStep;
119 m_pageStep = pageStep;
120 m_pixelStep = 1.0f / pixelsPerStep;
121}
122
123void Scrollbar::updateThumb()
124{
125#ifdef THUMB_POSITION_AFFECTS_BUTTONS
126 invalidate();
127#else
128 theme().invalidateParts(*this, ForwardTrackPart | BackTrackPart | ThumbPart);
129#endif
130}
131
132void Scrollbar::updateThumbPosition()
133{
134 updateThumb();
135}
136
137void Scrollbar::updateThumbProportion()
138{
139 updateThumb();
140}
141
142void Scrollbar::paint(GraphicsContext& context, const IntRect& damageRect, Widget::SecurityOriginPaintPolicy)
143{
144 if (context.invalidatingControlTints() && theme().supportsControlTints()) {
145 invalidate();
146 return;
147 }
148
149 if (context.paintingDisabled() || !frameRect().intersects(damageRect))
150 return;
151
152 if (!theme().paint(*this, context, damageRect))
153 Widget::paint(context, damageRect);
154}
155
156void Scrollbar::autoscrollTimerFired()
157{
158 autoscrollPressedPart(theme().autoscrollTimerDelay());
159}
160
161static bool thumbUnderMouse(Scrollbar* scrollbar)
162{
163 int thumbPos = scrollbar->theme().trackPosition(*scrollbar) + scrollbar->theme().thumbPosition(*scrollbar);
164 int thumbLength = scrollbar->theme().thumbLength(*scrollbar);
165 return scrollbar->pressedPos() >= thumbPos && scrollbar->pressedPos() < thumbPos + thumbLength;
166}
167
168void Scrollbar::autoscrollPressedPart(Seconds delay)
169{
170 // Don't do anything for the thumb or if nothing was pressed.
171 if (m_pressedPart == ThumbPart || m_pressedPart == NoPart)
172 return;
173
174 // Handle the track.
175 if ((m_pressedPart == BackTrackPart || m_pressedPart == ForwardTrackPart) && thumbUnderMouse(this)) {
176 theme().invalidatePart(*this, m_pressedPart);
177 setHoveredPart(ThumbPart);
178 return;
179 }
180
181 // Handle the arrows and track.
182 if (m_scrollableArea.scroll(pressedPartScrollDirection(), pressedPartScrollGranularity()))
183 startTimerIfNeeded(delay);
184}
185
186void Scrollbar::startTimerIfNeeded(Seconds delay)
187{
188 // Don't do anything for the thumb.
189 if (m_pressedPart == ThumbPart)
190 return;
191
192 // Handle the track. We halt track scrolling once the thumb is level
193 // with us.
194 if ((m_pressedPart == BackTrackPart || m_pressedPart == ForwardTrackPart) && thumbUnderMouse(this)) {
195 theme().invalidatePart(*this, m_pressedPart);
196 setHoveredPart(ThumbPart);
197 return;
198 }
199
200 // We can't scroll if we've hit the beginning or end.
201 ScrollDirection dir = pressedPartScrollDirection();
202 if (dir == ScrollUp || dir == ScrollLeft) {
203 if (m_currentPos == 0)
204 return;
205 } else {
206 if (m_currentPos == maximum())
207 return;
208 }
209
210 m_scrollTimer.startOneShot(delay);
211}
212
213void Scrollbar::stopTimerIfNeeded()
214{
215 if (m_scrollTimer.isActive())
216 m_scrollTimer.stop();
217}
218
219ScrollDirection Scrollbar::pressedPartScrollDirection()
220{
221 if (m_orientation == HorizontalScrollbar) {
222 if (m_pressedPart == BackButtonStartPart || m_pressedPart == BackButtonEndPart || m_pressedPart == BackTrackPart)
223 return ScrollLeft;
224 return ScrollRight;
225 } else {
226 if (m_pressedPart == BackButtonStartPart || m_pressedPart == BackButtonEndPart || m_pressedPart == BackTrackPart)
227 return ScrollUp;
228 return ScrollDown;
229 }
230}
231
232ScrollGranularity Scrollbar::pressedPartScrollGranularity()
233{
234 if (m_pressedPart == BackButtonStartPart || m_pressedPart == BackButtonEndPart || m_pressedPart == ForwardButtonStartPart || m_pressedPart == ForwardButtonEndPart)
235 return ScrollByLine;
236 return ScrollByPage;
237}
238
239void Scrollbar::moveThumb(int pos, bool draggingDocument)
240{
241 int delta = pos - m_pressedPos;
242
243 if (draggingDocument) {
244 if (m_draggingDocument)
245 delta = pos - m_documentDragPos;
246 m_draggingDocument = true;
247 FloatPoint currentPosition = m_scrollableArea.scrollAnimator().currentPosition();
248 int destinationPosition = (m_orientation == HorizontalScrollbar ? currentPosition.x() : currentPosition.y()) + delta;
249 if (delta > 0)
250 destinationPosition = std::min(destinationPosition + delta, maximum());
251 else if (delta < 0)
252 destinationPosition = std::max(destinationPosition + delta, 0);
253 m_scrollableArea.scrollToOffsetWithoutAnimation(m_orientation, destinationPosition);
254 m_documentDragPos = pos;
255 return;
256 }
257
258 if (m_draggingDocument) {
259 delta += m_pressedPos - m_documentDragPos;
260 m_draggingDocument = false;
261 }
262
263 // Drag the thumb.
264 int thumbPos = theme().thumbPosition(*this);
265 int thumbLen = theme().thumbLength(*this);
266 int trackLen = theme().trackLength(*this);
267 int maxPos = trackLen - thumbLen;
268 if (delta > 0)
269 delta = std::min(maxPos - thumbPos, delta);
270 else if (delta < 0)
271 delta = std::max(-thumbPos, delta);
272
273 if (delta) {
274 float newPosition = static_cast<float>(thumbPos + delta) * maximum() / (trackLen - thumbLen);
275 m_scrollableArea.scrollToOffsetWithoutAnimation(m_orientation, newPosition);
276 }
277}
278
279void Scrollbar::setHoveredPart(ScrollbarPart part)
280{
281 if (part == m_hoveredPart)
282 return;
283
284 if ((m_hoveredPart == NoPart || part == NoPart) && theme().invalidateOnMouseEnterExit())
285 invalidate(); // Just invalidate the whole scrollbar, since the buttons at either end change anyway.
286 else if (m_pressedPart == NoPart) { // When there's a pressed part, we don't draw a hovered state, so there's no reason to invalidate.
287 theme().invalidatePart(*this, part);
288 theme().invalidatePart(*this, m_hoveredPart);
289 }
290 m_hoveredPart = part;
291}
292
293void Scrollbar::setPressedPart(ScrollbarPart part)
294{
295 if (m_pressedPart != NoPart)
296 theme().invalidatePart(*this, m_pressedPart);
297 m_pressedPart = part;
298 if (m_pressedPart != NoPart)
299 theme().invalidatePart(*this, m_pressedPart);
300 else if (m_hoveredPart != NoPart) // When we no longer have a pressed part, we can start drawing a hovered state on the hovered part.
301 theme().invalidatePart(*this, m_hoveredPart);
302}
303
304#if !PLATFORM(IOS_FAMILY)
305bool Scrollbar::mouseMoved(const PlatformMouseEvent& evt)
306{
307 if (m_pressedPart == ThumbPart) {
308 if (theme().shouldSnapBackToDragOrigin(*this, evt))
309 m_scrollableArea.scrollToOffsetWithoutAnimation(m_orientation, m_dragOrigin);
310 else {
311 moveThumb(m_orientation == HorizontalScrollbar ?
312 convertFromContainingWindow(evt.position()).x() :
313 convertFromContainingWindow(evt.position()).y(), theme().shouldDragDocumentInsteadOfThumb(*this, evt));
314 }
315 return true;
316 }
317
318 if (m_pressedPart != NoPart)
319 m_pressedPos = (orientation() == HorizontalScrollbar ? convertFromContainingWindow(evt.position()).x() : convertFromContainingWindow(evt.position()).y());
320
321 ScrollbarPart part = theme().hitTest(*this, evt.position());
322 if (part != m_hoveredPart) {
323 if (m_pressedPart != NoPart) {
324 if (part == m_pressedPart) {
325 // The mouse is moving back over the pressed part. We
326 // need to start up the timer action again.
327 startTimerIfNeeded(theme().autoscrollTimerDelay());
328 theme().invalidatePart(*this, m_pressedPart);
329 } else if (m_hoveredPart == m_pressedPart) {
330 // The mouse is leaving the pressed part. Kill our timer
331 // if needed.
332 stopTimerIfNeeded();
333 theme().invalidatePart(*this, m_pressedPart);
334 }
335 }
336
337 setHoveredPart(part);
338 }
339
340 return true;
341}
342#endif
343
344void Scrollbar::mouseEntered()
345{
346 m_scrollableArea.mouseEnteredScrollbar(this);
347}
348
349bool Scrollbar::mouseExited()
350{
351 m_scrollableArea.mouseExitedScrollbar(this);
352 setHoveredPart(NoPart);
353 return true;
354}
355
356bool Scrollbar::mouseUp(const PlatformMouseEvent& mouseEvent)
357{
358 setPressedPart(NoPart);
359 m_pressedPos = 0;
360 m_draggingDocument = false;
361 stopTimerIfNeeded();
362
363 m_scrollableArea.mouseIsDownInScrollbar(this, false);
364
365 // m_hoveredPart won't be updated until the next mouseMoved or mouseDown, so we have to hit test
366 // to really know if the mouse has exited the scrollbar on a mouseUp.
367 ScrollbarPart part = theme().hitTest(*this, mouseEvent.position());
368 if (part == NoPart)
369 m_scrollableArea.mouseExitedScrollbar(this);
370
371 return true;
372}
373
374bool Scrollbar::mouseDown(const PlatformMouseEvent& evt)
375{
376 ScrollbarPart pressedPart = theme().hitTest(*this, evt.position());
377 auto action = theme().handleMousePressEvent(*this, evt, pressedPart);
378 if (action == ScrollbarButtonPressAction::None)
379 return true;
380
381 m_scrollableArea.mouseIsDownInScrollbar(this, true);
382 setPressedPart(pressedPart);
383
384 int pressedPosition = (orientation() == HorizontalScrollbar ? convertFromContainingWindow(evt.position()).x() : convertFromContainingWindow(evt.position()).y());
385 if (action == ScrollbarButtonPressAction::CenterOnThumb) {
386 setHoveredPart(ThumbPart);
387 setPressedPart(ThumbPart);
388 m_dragOrigin = m_currentPos;
389 // Set the pressed position to the middle of the thumb so that when we do the move, the delta
390 // will be from the current pixel position of the thumb to the new desired position for the thumb.
391 m_pressedPos = theme().trackPosition(*this) + theme().thumbPosition(*this) + theme().thumbLength(*this) / 2;
392 moveThumb(pressedPosition);
393 return true;
394 }
395
396 m_pressedPos = pressedPosition;
397
398 if (action == ScrollbarButtonPressAction::StartDrag)
399 m_dragOrigin = m_currentPos;
400
401 if (action == ScrollbarButtonPressAction::Scroll)
402 autoscrollPressedPart(theme().initialAutoscrollTimerDelay());
403
404 return true;
405}
406
407void Scrollbar::setEnabled(bool e)
408{
409 if (m_enabled == e)
410 return;
411 m_enabled = e;
412 theme().updateEnabledState(*this);
413 invalidate();
414}
415
416bool Scrollbar::isOverlayScrollbar() const
417{
418 return theme().usesOverlayScrollbars();
419}
420
421bool Scrollbar::shouldParticipateInHitTesting()
422{
423 // Non-overlay scrollbars should always participate in hit testing.
424 if (!isOverlayScrollbar())
425 return true;
426 return m_scrollableArea.scrollAnimator().shouldScrollbarParticipateInHitTesting(this);
427}
428
429bool Scrollbar::isWindowActive() const
430{
431 return m_scrollableArea.isActive();
432}
433
434void Scrollbar::invalidateRect(const IntRect& rect)
435{
436 if (suppressInvalidation())
437 return;
438
439 m_scrollableArea.invalidateScrollbar(*this, rect);
440}
441
442IntRect Scrollbar::convertToContainingView(const IntRect& localRect) const
443{
444 return m_scrollableArea.convertFromScrollbarToContainingView(*this, localRect);
445}
446
447IntRect Scrollbar::convertFromContainingView(const IntRect& parentRect) const
448{
449 return m_scrollableArea.convertFromContainingViewToScrollbar(*this, parentRect);
450}
451
452IntPoint Scrollbar::convertToContainingView(const IntPoint& localPoint) const
453{
454 return m_scrollableArea.convertFromScrollbarToContainingView(*this, localPoint);
455}
456
457IntPoint Scrollbar::convertFromContainingView(const IntPoint& parentPoint) const
458{
459 return m_scrollableArea.convertFromContainingViewToScrollbar(*this, parentPoint);
460}
461
462bool Scrollbar::supportsUpdateOnSecondaryThread() const
463{
464 // It's unfortunate that this needs to be done with an ifdef. Ideally there would be a way to feature-detect
465 // the necessary support within AppKit.
466#if ENABLE(ASYNC_SCROLLING) && PLATFORM(MAC)
467 return !m_scrollableArea.forceUpdateScrollbarsOnMainThreadForPerformanceTesting()
468 && (m_scrollableArea.hasLayerForVerticalScrollbar() || m_scrollableArea.hasLayerForHorizontalScrollbar())
469 && m_scrollableArea.usesAsyncScrolling();
470#else
471 return false;
472#endif
473}
474
475} // namespace WebCore
476