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| 1 /* | |
| 2 * Copyright (C) 2011 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. AND ITS CONTRIBUTORS ``AS IS'' | |
| 14 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, | |
| 15 * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR | |
| 16 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR ITS CONTRIBUTORS | |
| 17 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR | |
| 18 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF | |
| 19 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS | |
| 20 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN | |
| 21 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) | |
| 22 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF | |
| 23 * THE POSSIBILITY OF SUCH DAMAGE. | |
| 24 */ | |
| 25 | |
| 26 #include "config.h" | |
| 27 #include "core/platform/mac/ScrollElasticityController.h" | |
| 28 | |
| 29 #include "platform/PlatformWheelEvent.h" | |
| 30 #include <sys/sysctl.h> | |
| 31 #include <sys/time.h> | |
| 32 | |
| 33 #if USE(RUBBER_BANDING) | |
| 34 | |
| 35 static NSTimeInterval systemUptime() | |
| 36 { | |
| 37 if ([[NSProcessInfo processInfo] respondsToSelector:@selector(systemUptime)]
) | |
| 38 return [[NSProcessInfo processInfo] systemUptime]; | |
| 39 | |
| 40 // Get how long system has been up. Found by looking getting "boottime" from
the kernel. | |
| 41 static struct timeval boottime = {0, 0}; | |
| 42 if (!boottime.tv_sec) { | |
| 43 int mib[2] = {CTL_KERN, KERN_BOOTTIME}; | |
| 44 size_t size = sizeof(boottime); | |
| 45 if (-1 == sysctl(mib, 2, &boottime, &size, 0, 0)) | |
| 46 boottime.tv_sec = 0; | |
| 47 } | |
| 48 struct timeval now; | |
| 49 if (boottime.tv_sec && -1 != gettimeofday(&now, 0)) { | |
| 50 struct timeval uptime; | |
| 51 timersub(&now, &boottime, &uptime); | |
| 52 NSTimeInterval result = uptime.tv_sec + (uptime.tv_usec / 1E+6); | |
| 53 return result; | |
| 54 } | |
| 55 return 0; | |
| 56 } | |
| 57 | |
| 58 namespace WebCore { | |
| 59 | |
| 60 static const float scrollVelocityZeroingTimeout = 0.10f; | |
| 61 static const float rubberbandDirectionLockStretchRatio = 1; | |
| 62 static const float rubberbandMinimumRequiredDeltaBeforeStretch = 10; | |
| 63 | |
| 64 static const float rubberbandStiffness = 20; | |
| 65 static const float rubberbandAmplitude = 0.31f; | |
| 66 static const float rubberbandPeriod = 1.6f; | |
| 67 | |
| 68 static float elasticDeltaForTimeDelta(float initialPosition, float initialVeloci
ty, float elapsedTime) | |
| 69 { | |
| 70 float amplitude = rubberbandAmplitude; | |
| 71 float period = rubberbandPeriod; | |
| 72 float criticalDampeningFactor = expf((-elapsedTime * rubberbandStiffness) /
period); | |
| 73 | |
| 74 return (initialPosition + (-initialVelocity * elapsedTime * amplitude)) * cr
iticalDampeningFactor; | |
| 75 } | |
| 76 | |
| 77 static float elasticDeltaForReboundDelta(float delta) | |
| 78 { | |
| 79 float stiffness = std::max(rubberbandStiffness, 1.0f); | |
| 80 return delta / stiffness; | |
| 81 } | |
| 82 | |
| 83 static float reboundDeltaForElasticDelta(float delta) | |
| 84 { | |
| 85 return delta * rubberbandStiffness; | |
| 86 } | |
| 87 | |
| 88 static float scrollWheelMultiplier() | |
| 89 { | |
| 90 static float multiplier = -1; | |
| 91 if (multiplier < 0) { | |
| 92 multiplier = [[NSUserDefaults standardUserDefaults] floatForKey:@"NSScro
llWheelMultiplier"]; | |
| 93 if (multiplier <= 0) | |
| 94 multiplier = 1; | |
| 95 } | |
| 96 return multiplier; | |
| 97 } | |
| 98 | |
| 99 ScrollElasticityController::ScrollElasticityController(ScrollElasticityControlle
rClient* client) | |
| 100 : m_client(client) | |
| 101 , m_inScrollGesture(false) | |
| 102 , m_momentumScrollInProgress(false) | |
| 103 , m_ignoreMomentumScrolls(false) | |
| 104 , m_lastMomentumScrollTimestamp(0) | |
| 105 , m_startTime(0) | |
| 106 , m_snapRubberbandTimerIsActive(false) | |
| 107 { | |
| 108 } | |
| 109 | |
| 110 bool ScrollElasticityController::handleWheelEvent(const PlatformWheelEvent& whee
lEvent) | |
| 111 { | |
| 112 if (wheelEvent.phase() == PlatformWheelEventPhaseBegan) { | |
| 113 // First, check if we should rubber-band at all. | |
| 114 if (m_client->pinnedInDirection(FloatSize(-wheelEvent.deltaX(), 0)) && | |
| 115 !shouldRubberBandInHorizontalDirection(wheelEvent)) | |
| 116 return false; | |
| 117 | |
| 118 m_inScrollGesture = true; | |
| 119 m_momentumScrollInProgress = false; | |
| 120 m_ignoreMomentumScrolls = false; | |
| 121 m_lastMomentumScrollTimestamp = 0; | |
| 122 m_momentumVelocity = FloatSize(); | |
| 123 | |
| 124 IntSize stretchAmount = m_client->stretchAmount(); | |
| 125 m_stretchScrollForce.setWidth(reboundDeltaForElasticDelta(stretchAmount.
width())); | |
| 126 m_stretchScrollForce.setHeight(reboundDeltaForElasticDelta(stretchAmount
.height())); | |
| 127 m_overflowScrollDelta = FloatSize(); | |
| 128 | |
| 129 stopSnapRubberbandTimer(); | |
| 130 | |
| 131 return true; | |
| 132 } | |
| 133 | |
| 134 if (wheelEvent.phase() == PlatformWheelEventPhaseEnded) { | |
| 135 bool wasRubberBandInProgress = isRubberBandInProgress(); | |
| 136 // Call snapRubberBand() even if isRubberBandInProgress() is false. For
example, | |
| 137 // m_inScrollGesture may be true (and needs to be reset on a phase end)
even if | |
| 138 // isRubberBandInProgress() is not (e.g. the overhang area is empty). | |
| 139 snapRubberBand(); | |
| 140 return wasRubberBandInProgress; | |
| 141 } | |
| 142 | |
| 143 bool isMomentumScrollEvent = (wheelEvent.momentumPhase() != PlatformWheelEve
ntPhaseNone); | |
| 144 if (m_ignoreMomentumScrolls && (isMomentumScrollEvent || m_snapRubberbandTim
erIsActive)) { | |
| 145 if (wheelEvent.momentumPhase() == PlatformWheelEventPhaseEnded) { | |
| 146 m_ignoreMomentumScrolls = false; | |
| 147 return true; | |
| 148 } | |
| 149 return false; | |
| 150 } | |
| 151 | |
| 152 float deltaX = m_overflowScrollDelta.width(); | |
| 153 float deltaY = m_overflowScrollDelta.height(); | |
| 154 | |
| 155 // Reset overflow values because we may decide to remove delta at various po
ints and put it into overflow. | |
| 156 m_overflowScrollDelta = FloatSize(); | |
| 157 | |
| 158 IntSize stretchAmount = m_client->stretchAmount(); | |
| 159 bool isVerticallyStretched = stretchAmount.height(); | |
| 160 bool isHorizontallyStretched = stretchAmount.width(); | |
| 161 | |
| 162 float eventCoalescedDeltaX; | |
| 163 float eventCoalescedDeltaY; | |
| 164 | |
| 165 if (isVerticallyStretched || isHorizontallyStretched) { | |
| 166 eventCoalescedDeltaX = -wheelEvent.unacceleratedScrollingDeltaX(); | |
| 167 eventCoalescedDeltaY = -wheelEvent.unacceleratedScrollingDeltaY(); | |
| 168 } else { | |
| 169 eventCoalescedDeltaX = -wheelEvent.deltaX(); | |
| 170 eventCoalescedDeltaY = -wheelEvent.deltaY(); | |
| 171 } | |
| 172 | |
| 173 deltaX += eventCoalescedDeltaX; | |
| 174 deltaY += eventCoalescedDeltaY; | |
| 175 | |
| 176 // Slightly prefer scrolling vertically by applying the = case to deltaY | |
| 177 if (fabsf(deltaY) >= fabsf(deltaX)) | |
| 178 deltaX = 0; | |
| 179 else | |
| 180 deltaY = 0; | |
| 181 | |
| 182 bool shouldStretch = false; | |
| 183 | |
| 184 PlatformWheelEventPhase momentumPhase = wheelEvent.momentumPhase(); | |
| 185 | |
| 186 // If we are starting momentum scrolling then do some setup. | |
| 187 if (!m_momentumScrollInProgress && (momentumPhase == PlatformWheelEventPhase
Began || momentumPhase == PlatformWheelEventPhaseChanged)) { | |
| 188 m_momentumScrollInProgress = true; | |
| 189 // Start the snap rubber band timer if it's not running. This is needed
to | |
| 190 // snap back from the over scroll caused by momentum events. | |
| 191 if (!m_snapRubberbandTimerIsActive && m_startTime == 0) | |
| 192 snapRubberBand(); | |
| 193 } | |
| 194 | |
| 195 CFTimeInterval timeDelta = wheelEvent.timestamp() - m_lastMomentumScrollTime
stamp; | |
| 196 if (m_inScrollGesture || m_momentumScrollInProgress) { | |
| 197 if (m_lastMomentumScrollTimestamp && timeDelta > 0 && timeDelta < scroll
VelocityZeroingTimeout) { | |
| 198 m_momentumVelocity.setWidth(eventCoalescedDeltaX / (float)timeDelta)
; | |
| 199 m_momentumVelocity.setHeight(eventCoalescedDeltaY / (float)timeDelta
); | |
| 200 m_lastMomentumScrollTimestamp = wheelEvent.timestamp(); | |
| 201 } else { | |
| 202 m_lastMomentumScrollTimestamp = wheelEvent.timestamp(); | |
| 203 m_momentumVelocity = FloatSize(); | |
| 204 } | |
| 205 | |
| 206 if (isVerticallyStretched) { | |
| 207 if (!isHorizontallyStretched && m_client->pinnedInDirection(FloatSiz
e(deltaX, 0))) { | |
| 208 // Stretching only in the vertical. | |
| 209 if (deltaY != 0 && (fabsf(deltaX / deltaY) < rubberbandDirection
LockStretchRatio)) | |
| 210 deltaX = 0; | |
| 211 else if (fabsf(deltaX) < rubberbandMinimumRequiredDeltaBeforeStr
etch) { | |
| 212 m_overflowScrollDelta.setWidth(m_overflowScrollDelta.width()
+ deltaX); | |
| 213 deltaX = 0; | |
| 214 } else | |
| 215 m_overflowScrollDelta.setWidth(m_overflowScrollDelta.width()
+ deltaX); | |
| 216 } | |
| 217 } else if (isHorizontallyStretched) { | |
| 218 // Stretching only in the horizontal. | |
| 219 if (m_client->pinnedInDirection(FloatSize(0, deltaY))) { | |
| 220 if (deltaX != 0 && (fabsf(deltaY / deltaX) < rubberbandDirection
LockStretchRatio)) | |
| 221 deltaY = 0; | |
| 222 else if (fabsf(deltaY) < rubberbandMinimumRequiredDeltaBeforeStr
etch) { | |
| 223 m_overflowScrollDelta.setHeight(m_overflowScrollDelta.height
() + deltaY); | |
| 224 deltaY = 0; | |
| 225 } else | |
| 226 m_overflowScrollDelta.setHeight(m_overflowScrollDelta.height
() + deltaY); | |
| 227 } | |
| 228 } else { | |
| 229 // Not stretching at all yet. | |
| 230 if (m_client->pinnedInDirection(FloatSize(deltaX, deltaY))) { | |
| 231 if (fabsf(deltaY) >= fabsf(deltaX)) { | |
| 232 if (fabsf(deltaX) < rubberbandMinimumRequiredDeltaBeforeStre
tch) { | |
| 233 m_overflowScrollDelta.setWidth(m_overflowScrollDelta.wid
th() + deltaX); | |
| 234 deltaX = 0; | |
| 235 } else | |
| 236 m_overflowScrollDelta.setWidth(m_overflowScrollDelta.wid
th() + deltaX); | |
| 237 } | |
| 238 shouldStretch = true; | |
| 239 } | |
| 240 } | |
| 241 } | |
| 242 | |
| 243 if (deltaX != 0 || deltaY != 0) { | |
| 244 if (!(shouldStretch || isVerticallyStretched || isHorizontallyStretched)
) { | |
| 245 if (deltaY != 0) { | |
| 246 deltaY *= scrollWheelMultiplier(); | |
| 247 m_client->immediateScrollBy(FloatSize(0, deltaY)); | |
| 248 } | |
| 249 if (deltaX != 0) { | |
| 250 deltaX *= scrollWheelMultiplier(); | |
| 251 m_client->immediateScrollBy(FloatSize(deltaX, 0)); | |
| 252 } | |
| 253 } else { | |
| 254 if (!m_client->allowsHorizontalStretching()) { | |
| 255 deltaX = 0; | |
| 256 eventCoalescedDeltaX = 0; | |
| 257 } else if ((deltaX != 0) && !isHorizontallyStretched && !m_client->p
innedInDirection(FloatSize(deltaX, 0))) { | |
| 258 deltaX *= scrollWheelMultiplier(); | |
| 259 | |
| 260 m_client->immediateScrollByWithoutContentEdgeConstraints(FloatSi
ze(deltaX, 0)); | |
| 261 deltaX = 0; | |
| 262 } | |
| 263 | |
| 264 if (!m_client->allowsVerticalStretching()) { | |
| 265 deltaY = 0; | |
| 266 eventCoalescedDeltaY = 0; | |
| 267 } else if ((deltaY != 0) && !isVerticallyStretched && !m_client->pin
nedInDirection(FloatSize(0, deltaY))) { | |
| 268 deltaY *= scrollWheelMultiplier(); | |
| 269 | |
| 270 m_client->immediateScrollByWithoutContentEdgeConstraints(FloatSi
ze(0, deltaY)); | |
| 271 deltaY = 0; | |
| 272 } | |
| 273 | |
| 274 IntSize stretchAmount = m_client->stretchAmount(); | |
| 275 | |
| 276 if (m_momentumScrollInProgress) { | |
| 277 if ((m_client->pinnedInDirection(FloatSize(eventCoalescedDeltaX,
eventCoalescedDeltaY)) || (fabsf(eventCoalescedDeltaX) + fabsf(eventCoalescedDe
ltaY) <= 0)) && m_lastMomentumScrollTimestamp) { | |
| 278 m_ignoreMomentumScrolls = true; | |
| 279 m_momentumScrollInProgress = false; | |
| 280 snapRubberBand(); | |
| 281 } | |
| 282 } | |
| 283 | |
| 284 m_stretchScrollForce.setWidth(m_stretchScrollForce.width() + deltaX)
; | |
| 285 m_stretchScrollForce.setHeight(m_stretchScrollForce.height() + delta
Y); | |
| 286 | |
| 287 FloatSize dampedDelta(ceilf(elasticDeltaForReboundDelta(m_stretchScr
ollForce.width())), ceilf(elasticDeltaForReboundDelta(m_stretchScrollForce.heigh
t()))); | |
| 288 | |
| 289 m_client->immediateScrollByWithoutContentEdgeConstraints(dampedDelta
- stretchAmount); | |
| 290 } | |
| 291 } | |
| 292 | |
| 293 if (m_momentumScrollInProgress && momentumPhase == PlatformWheelEventPhaseEn
ded) { | |
| 294 m_momentumScrollInProgress = false; | |
| 295 m_ignoreMomentumScrolls = false; | |
| 296 m_lastMomentumScrollTimestamp = 0; | |
| 297 } | |
| 298 | |
| 299 return true; | |
| 300 } | |
| 301 | |
| 302 static inline float roundTowardZero(float num) | |
| 303 { | |
| 304 return num > 0 ? ceilf(num - 0.5f) : floorf(num + 0.5f); | |
| 305 } | |
| 306 | |
| 307 static inline float roundToDevicePixelTowardZero(float num) | |
| 308 { | |
| 309 float roundedNum = roundf(num); | |
| 310 if (fabs(num - roundedNum) < 0.125) | |
| 311 num = roundedNum; | |
| 312 | |
| 313 return roundTowardZero(num); | |
| 314 } | |
| 315 | |
| 316 void ScrollElasticityController::snapRubberBandTimerFired() | |
| 317 { | |
| 318 if (!m_momentumScrollInProgress || m_ignoreMomentumScrolls) { | |
| 319 CFTimeInterval timeDelta = [NSDate timeIntervalSinceReferenceDate] - m_s
tartTime; | |
| 320 | |
| 321 if (m_startStretch == FloatSize()) { | |
| 322 m_startStretch = m_client->stretchAmount(); | |
| 323 if (m_startStretch == FloatSize()) { | |
| 324 stopSnapRubberbandTimer(); | |
| 325 | |
| 326 m_stretchScrollForce = FloatSize(); | |
| 327 m_startTime = 0; | |
| 328 m_origOrigin = FloatPoint(); | |
| 329 m_origVelocity = FloatSize(); | |
| 330 return; | |
| 331 } | |
| 332 | |
| 333 m_origOrigin = m_client->absoluteScrollPosition() - m_startStretch; | |
| 334 m_origVelocity = m_momentumVelocity; | |
| 335 | |
| 336 // Just like normal scrolling, prefer vertical rubberbanding | |
| 337 if (fabsf(m_origVelocity.height()) >= fabsf(m_origVelocity.width())) | |
| 338 m_origVelocity.setWidth(0); | |
| 339 | |
| 340 // Don't rubber-band horizontally if it's not possible to scroll hor
izontally | |
| 341 if (!m_client->canScrollHorizontally()) | |
| 342 m_origVelocity.setWidth(0); | |
| 343 | |
| 344 // Don't rubber-band vertically if it's not possible to scroll verti
cally | |
| 345 if (!m_client->canScrollVertically()) | |
| 346 m_origVelocity.setHeight(0); | |
| 347 } | |
| 348 | |
| 349 FloatPoint delta(roundToDevicePixelTowardZero(elasticDeltaForTimeDelta(m
_startStretch.width(), -m_origVelocity.width(), (float)timeDelta)), | |
| 350 roundToDevicePixelTowardZero(elasticDeltaForTimeDelta(m
_startStretch.height(), -m_origVelocity.height(), (float)timeDelta))); | |
| 351 | |
| 352 if (fabs(delta.x()) >= 1 || fabs(delta.y()) >= 1) { | |
| 353 m_client->immediateScrollByWithoutContentEdgeConstraints(FloatSize(d
elta.x(), delta.y()) - m_client->stretchAmount()); | |
| 354 | |
| 355 FloatSize newStretch = m_client->stretchAmount(); | |
| 356 | |
| 357 m_stretchScrollForce.setWidth(reboundDeltaForElasticDelta(newStretch
.width())); | |
| 358 m_stretchScrollForce.setHeight(reboundDeltaForElasticDelta(newStretc
h.height())); | |
| 359 } else { | |
| 360 m_client->immediateScrollBy(m_origOrigin - m_client->absoluteScrollP
osition()); | |
| 361 | |
| 362 stopSnapRubberbandTimer(); | |
| 363 m_stretchScrollForce = FloatSize(); | |
| 364 m_startTime = 0; | |
| 365 m_startStretch = FloatSize(); | |
| 366 m_origOrigin = FloatPoint(); | |
| 367 m_origVelocity = FloatSize(); | |
| 368 } | |
| 369 } else { | |
| 370 m_startTime = [NSDate timeIntervalSinceReferenceDate]; | |
| 371 m_startStretch = FloatSize(); | |
| 372 } | |
| 373 } | |
| 374 | |
| 375 bool ScrollElasticityController::isRubberBandInProgress() const | |
| 376 { | |
| 377 if (!m_inScrollGesture && !m_momentumScrollInProgress && !m_snapRubberbandTi
merIsActive) | |
| 378 return false; | |
| 379 | |
| 380 return !m_client->stretchAmount().isZero(); | |
| 381 } | |
| 382 | |
| 383 void ScrollElasticityController::stopSnapRubberbandTimer() | |
| 384 { | |
| 385 m_client->stopSnapRubberbandTimer(); | |
| 386 m_snapRubberbandTimerIsActive = false; | |
| 387 } | |
| 388 | |
| 389 void ScrollElasticityController::snapRubberBand() | |
| 390 { | |
| 391 CFTimeInterval timeDelta = systemUptime() - m_lastMomentumScrollTimestamp; | |
| 392 if (m_lastMomentumScrollTimestamp && timeDelta >= scrollVelocityZeroingTimeo
ut) | |
| 393 m_momentumVelocity = FloatSize(); | |
| 394 | |
| 395 m_inScrollGesture = false; | |
| 396 | |
| 397 if (m_snapRubberbandTimerIsActive) | |
| 398 return; | |
| 399 | |
| 400 m_startStretch = FloatSize(); | |
| 401 m_origOrigin = FloatPoint(); | |
| 402 m_origVelocity = FloatSize(); | |
| 403 | |
| 404 // If there's no momentum scroll or stretch amount, no need to start the tim
er. | |
| 405 if (!m_momentumScrollInProgress && m_client->stretchAmount() == FloatSize())
{ | |
| 406 m_startTime = 0; | |
| 407 m_stretchScrollForce = FloatSize(); | |
| 408 return; | |
| 409 } | |
| 410 | |
| 411 m_startTime = [NSDate timeIntervalSinceReferenceDate]; | |
| 412 m_client->startSnapRubberbandTimer(); | |
| 413 m_snapRubberbandTimerIsActive = true; | |
| 414 } | |
| 415 | |
| 416 bool ScrollElasticityController::shouldRubberBandInHorizontalDirection(const Pla
tformWheelEvent& wheelEvent) | |
| 417 { | |
| 418 if (wheelEvent.deltaX() > 0) | |
| 419 return m_client->shouldRubberBandInDirection(ScrollLeft); | |
| 420 if (wheelEvent.deltaX() < 0) | |
| 421 return m_client->shouldRubberBandInDirection(ScrollRight); | |
| 422 | |
| 423 return true; | |
| 424 } | |
| 425 | |
| 426 } // namespace WebCore | |
| 427 | |
| 428 #endif // USE(RUBBER_BANDING) | |
| OLD | NEW |
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Chromium Code Reviews
Issue 99103006:
Moving GraphicsContext and dependencies from core to platform. (Closed)
Base URL: svn://svn.chromium.org/blink/trunk