DXR is a code search and navigation tool aimed at making sense of large projects. It supports full-text and regex searches as well as structural queries.

Implementation

Mercurial (1aeaa33a64f9)

VCS Links

Line Code
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529
/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=8 sts=2 et sw=2 tw=80: */
/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

#ifndef mozilla_dom_Animation_h
#define mozilla_dom_Animation_h

#include "nsWrapperCache.h"
#include "nsCycleCollectionParticipant.h"
#include "mozilla/AnimationPerformanceWarning.h"
#include "mozilla/Attributes.h"
#include "mozilla/CycleCollectedJSContext.h"
#include "mozilla/DOMEventTargetHelper.h"
#include "mozilla/EffectCompositor.h"  // For EffectCompositor::CascadeLevel
#include "mozilla/LinkedList.h"
#include "mozilla/TimeStamp.h"             // for TimeStamp, TimeDuration
#include "mozilla/dom/AnimationBinding.h"  // for AnimationPlayState
#include "mozilla/dom/AnimationEffectReadOnly.h"
#include "mozilla/dom/AnimationTimeline.h"
#include "mozilla/dom/Promise.h"
#include "nsCSSPropertyID.h"
#include "nsIGlobalObject.h"

// X11 has a #define for CurrentTime.
#ifdef CurrentTime
#undef CurrentTime
#endif

// GetCurrentTime is defined in winbase.h as zero argument macro forwarding to
// GetTickCount().
#ifdef GetCurrentTime
#undef GetCurrentTime
#endif

struct JSContext;
class nsCSSPropertyIDSet;
class nsIDocument;
class nsIFrame;

namespace mozilla {

struct AnimationRule;

namespace dom {

class AsyncFinishNotification;
class CSSAnimation;
class CSSTransition;

class Animation : public DOMEventTargetHelper,
                  public LinkedListElement<Animation> {
 protected:
  virtual ~Animation() {}

 public:
  explicit Animation(nsIGlobalObject* aGlobal)
      : DOMEventTargetHelper(aGlobal),
        mPlaybackRate(1.0),
        mPendingState(PendingState::NotPending),
        mAnimationIndex(sNextAnimationIndex++),
        mFinishedAtLastComposeStyle(false),
        mIsRelevant(false),
        mFinishedIsResolved(false),
        mSyncWithGeometricAnimations(false) {}

  NS_DECL_ISUPPORTS_INHERITED
  NS_DECL_CYCLE_COLLECTION_CLASS_INHERITED(Animation, DOMEventTargetHelper)

  nsIGlobalObject* GetParentObject() const { return GetOwnerGlobal(); }
  virtual JSObject* WrapObject(JSContext* aCx,
                               JS::Handle<JSObject*> aGivenProto) override;

  virtual CSSAnimation* AsCSSAnimation() { return nullptr; }
  virtual const CSSAnimation* AsCSSAnimation() const { return nullptr; }
  virtual CSSTransition* AsCSSTransition() { return nullptr; }
  virtual const CSSTransition* AsCSSTransition() const { return nullptr; }

  /**
   * Flag to pass to Play to indicate whether or not it should automatically
   * rewind the current time to the start point if the animation is finished.
   * For regular calls to play() from script we should do this, but when a CSS
   * animation's animation-play-state changes we shouldn't rewind the animation.
   */
  enum class LimitBehavior { AutoRewind, Continue };

  // Animation interface methods
  static already_AddRefed<Animation> Constructor(
      const GlobalObject& aGlobal, AnimationEffectReadOnly* aEffect,
      const Optional<AnimationTimeline*>& aTimeline, ErrorResult& aRv);
  void GetId(nsAString& aResult) const { aResult = mId; }
  void SetId(const nsAString& aId);
  AnimationEffectReadOnly* GetEffect() const { return mEffect; }
  void SetEffect(AnimationEffectReadOnly* aEffect);
  AnimationTimeline* GetTimeline() const { return mTimeline; }
  void SetTimeline(AnimationTimeline* aTimeline);
  Nullable<TimeDuration> GetStartTime() const { return mStartTime; }
  void SetStartTime(const Nullable<TimeDuration>& aNewStartTime);
  Nullable<TimeDuration> GetCurrentTime() const {
    return GetCurrentTimeForHoldTime(mHoldTime);
  }
  void SetCurrentTime(const TimeDuration& aNewCurrentTime);
  double PlaybackRate() const { return mPlaybackRate; }
  void SetPlaybackRate(double aPlaybackRate);
  AnimationPlayState PlayState() const;
  bool Pending() const { return mPendingState != PendingState::NotPending; }
  virtual Promise* GetReady(ErrorResult& aRv);
  Promise* GetFinished(ErrorResult& aRv);
  void Cancel();
  void Finish(ErrorResult& aRv);
  virtual void Play(ErrorResult& aRv, LimitBehavior aLimitBehavior);
  virtual void Pause(ErrorResult& aRv);
  void Reverse(ErrorResult& aRv);
  void UpdatePlaybackRate(double aPlaybackRate);
  bool IsRunningOnCompositor() const;
  IMPL_EVENT_HANDLER(finish);
  IMPL_EVENT_HANDLER(cancel);

  // Wrapper functions for Animation DOM methods when called
  // from script.
  //
  // We often use the same methods internally and from script but when called
  // from script we (or one of our subclasses) perform extra steps such as
  // flushing style or converting the return type.
  Nullable<double> GetStartTimeAsDouble() const;
  void SetStartTimeAsDouble(const Nullable<double>& aStartTime);
  Nullable<double> GetCurrentTimeAsDouble() const;
  void SetCurrentTimeAsDouble(const Nullable<double>& aCurrentTime,
                              ErrorResult& aRv);
  virtual AnimationPlayState PlayStateFromJS() const { return PlayState(); }
  virtual bool PendingFromJS() const { return Pending(); }
  virtual void PlayFromJS(ErrorResult& aRv) {
    Play(aRv, LimitBehavior::AutoRewind);
  }
  /**
   * PauseFromJS is currently only here for symmetry with PlayFromJS but
   * in future we will likely have to flush style in
   * CSSAnimation::PauseFromJS so we leave it for now.
   */
  void PauseFromJS(ErrorResult& aRv) { Pause(aRv); }

  // Wrapper functions for Animation DOM methods when called from style.

  virtual void CancelFromStyle() { CancelNoUpdate(); }
  void SetTimelineNoUpdate(AnimationTimeline* aTimeline);
  void SetEffectNoUpdate(AnimationEffectReadOnly* aEffect);

  virtual void Tick();
  bool NeedsTicks() const {
    return Pending() || PlayState() == AnimationPlayState::Running;
  }

  /**
   * Set the time to use for starting or pausing a pending animation.
   *
   * Typically, when an animation is played, it does not start immediately but
   * is added to a table of pending animations on the document of its effect.
   * In the meantime it sets its hold time to the time from which playback
   * should begin.
   *
   * When the document finishes painting, any pending animations in its table
   * are marked as being ready to start by calling StartOnNextTick.
   * The moment when the paint completed is also recorded, converted to a
   * timeline time, and passed to StartOnTick. This is so that when these
   * animations do start, they can be timed from the point when painting
   * completed.
   *
   * After calling TriggerOnNextTick, animations remain in the pending state
   * until the next refresh driver tick. At that time they transition out of
   * the pending state using the time passed to TriggerOnNextTick as the
   * effective time at which they resumed.
   *
   * This approach means that any setup time required for performing the
   * initial paint of an animation such as layerization is not deducted from
   * the running time of the animation. Without this we can easily drop the
   * first few frames of an animation, or, on slower devices, the whole
   * animation.
   *
   * Furthermore:
   *
   * - Starting the animation immediately when painting finishes is problematic
   *   because the start time of the animation will be ahead of its timeline
   *   (since the timeline time is based on the refresh driver time).
   *   That's a problem because the animation is playing but its timing
   *   suggests it starts in the future. We could update the timeline to match
   *   the start time of the animation but then we'd also have to update the
   *   timing and style of all animations connected to that timeline or else be
   *   stuck in an inconsistent state until the next refresh driver tick.
   *
   * - If we simply use the refresh driver time on its next tick, the lag
   *   between triggering an animation and its effective start is unacceptably
   *   long.
   *
   * For pausing, we apply the same asynchronous approach. This is so that we
   * synchronize with animations that are running on the compositor. Otherwise
   * if the main thread lags behind the compositor there will be a noticeable
   * jump backwards when the main thread takes over. Even though main thread
   * animations could be paused immediately, we do it asynchronously for
   * consistency and so that animations paused together end up in step.
   *
   * Note that the caller of this method is responsible for removing the
   * animation from any PendingAnimationTracker it may have been added to.
   */
  void TriggerOnNextTick(const Nullable<TimeDuration>& aReadyTime);
  /**
   * Testing only: Start or pause a pending animation using the current
   * timeline time. This is used to support existing tests that expect
   * animations to begin immediately. Ideally we would rewrite the those tests
   * and get rid of this method, but there are a lot of them.
   *
   * As with TriggerOnNextTick, the caller of this method is responsible for
   * removing the animation from any PendingAnimationTracker it may have been
   * added to.
   */
  void TriggerNow();
  /**
   * When StartOnNextTick is called, we store the ready time but we don't apply
   * it until the next tick. In the meantime, GetStartTime() will return null.
   *
   * However, if we build layer animations again before the next tick, we
   * should initialize them with the start time that GetStartTime() will return
   * on the next tick.
   *
   * If we were to simply set the start time of layer animations to null, their
   * start time would be updated to the current wallclock time when rendering
   * finishes, thus making them out of sync with the start time stored here.
   * This, in turn, will make the animation jump backwards when we build
   * animations on the next tick and apply the start time stored here.
   *
   * This method returns the start time, if resolved. Otherwise, if we have
   * a pending ready time, it returns the corresponding start time. If neither
   * of those are available, it returns null.
   */
  Nullable<TimeDuration> GetCurrentOrPendingStartTime() const;

  /**
   * As with the start time, we should use the pending playback rate when
   * producing layer animations.
   */
  double CurrentOrPendingPlaybackRate() const {
    return mPendingPlaybackRate.valueOr(mPlaybackRate);
  }
  bool HasPendingPlaybackRate() const { return mPendingPlaybackRate.isSome(); }

  /**
   * The following relationship from the definition of the 'current time' is
   * re-used in many algorithms so we extract it here into a static method that
   * can be re-used:
   *
   *   current time = (timeline time - start time) * playback rate
   *
   * As per https://drafts.csswg.org/web-animations-1/#current-time
   */
  static TimeDuration CurrentTimeFromTimelineTime(
      const TimeDuration& aTimelineTime, const TimeDuration& aStartTime,
      float aPlaybackRate) {
    return (aTimelineTime - aStartTime).MultDouble(aPlaybackRate);
  }

  /**
   * As with calculating the current time, we often need to calculate a start
   * time from a current time. The following method simply inverts the current
   * time relationship.
   *
   * In each case where this is used, the desired behavior for playbackRate ==
   * 0 is to return the specified timeline time (often referred to as the ready
   * time).
   */
  static TimeDuration StartTimeFromTimelineTime(
      const TimeDuration& aTimelineTime, const TimeDuration& aCurrentTime,
      float aPlaybackRate) {
    TimeDuration result = aTimelineTime;
    if (aPlaybackRate == 0) {
      return result;
    }

    result -= aCurrentTime.MultDouble(1.0 / aPlaybackRate);
    return result;
  }

  /**
   * Converts a time in the timescale of this Animation's currentTime, to a
   * TimeStamp. Returns a null TimeStamp if the conversion cannot be performed
   * because of the current state of this Animation (e.g. it has no timeline, a
   * zero playbackRate, an unresolved start time etc.) or the value of the time
   * passed-in (e.g. an infinite time).
   */
  TimeStamp AnimationTimeToTimeStamp(const StickyTimeDuration& aTime) const;

  // Converts an AnimationEvent's elapsedTime value to an equivalent TimeStamp
  // that can be used to sort events by when they occurred.
  TimeStamp ElapsedTimeToTimeStamp(
      const StickyTimeDuration& aElapsedTime) const;

  bool IsPausedOrPausing() const {
    // FIXME: Once we drop the dom.animations-api.pending-member.enabled pref we
    // can simplify the following check to just:
    //
    //   return PlayState() == AnimationPlayState::Paused;
    //
    // And at that point we might not need this method at all.
    return PlayState() == AnimationPlayState::Paused ||
           mPendingState == PendingState::PausePending;
  }

  bool HasCurrentEffect() const {
    return GetEffect() && GetEffect()->IsCurrent();
  }
  bool IsInEffect() const { return GetEffect() && GetEffect()->IsInEffect(); }

  bool IsPlaying() const {
    // FIXME: Once we drop the dom.animations-api.pending-member.enabled pref we
    // can simplify the last two conditions to just:
    //
    //   PlayState() == AnimationPlayState::Running
    return mPlaybackRate != 0.0 && mTimeline &&
           !mTimeline->GetCurrentTime().IsNull() &&
           (PlayState() == AnimationPlayState::Running ||
            mPendingState == PendingState::PlayPending);
  }

  bool ShouldBeSynchronizedWithMainThread(
      nsCSSPropertyID aProperty, const nsIFrame* aFrame,
      AnimationPerformanceWarning::Type& aPerformanceWarning) const;

  bool IsRelevant() const { return mIsRelevant; }
  void UpdateRelevance();

  /**
   * Returns true if this Animation has a lower composite order than aOther.
   */
  bool HasLowerCompositeOrderThan(const Animation& aOther) const;

  /**
   * Returns the level at which the effect(s) associated with this Animation
   * are applied to the CSS cascade.
   */
  virtual EffectCompositor::CascadeLevel CascadeLevel() const {
    return EffectCompositor::CascadeLevel::Animations;
  }

  /**
   * Returns true if this animation does not currently need to update
   * style on the main thread (e.g. because it is empty, or is
   * running on the compositor).
   */
  bool CanThrottle() const;

  /**
   * Updates various bits of state that we need to update as the result of
   * running ComposeStyle().
   * See the comment of KeyframeEffectReadOnly::WillComposeStyle for more
   * detail.
   */
  void WillComposeStyle();

  /**
   * Updates |aComposeResult| with the animation values of this animation's
   * effect, if any.
   * Any properties contained in |aPropertiesToSkip| will not be added or
   * updated in |aComposeResult|.
   */
  template <typename ComposeAnimationResult>
  void ComposeStyle(ComposeAnimationResult&& aComposeResult,
                    const nsCSSPropertyIDSet& aPropertiesToSkip);

  void NotifyEffectTimingUpdated();
  void NotifyGeometricAnimationsStartingThisFrame();

  /**
   * Used by subclasses to synchronously queue a cancel event in situations
   * where the Animation may have been cancelled.
   *
   * We need to do this synchronously because after a CSS animation/transition
   * is canceled, it will be released by its owning element and may not still
   * exist when we would normally go to queue events on the next tick.
   */
  virtual void MaybeQueueCancelEvent(const StickyTimeDuration& aActiveTime){};

 protected:
  void SilentlySetCurrentTime(const TimeDuration& aNewCurrentTime);
  void CancelNoUpdate();
  void PlayNoUpdate(ErrorResult& aRv, LimitBehavior aLimitBehavior);
  void ResumeAt(const TimeDuration& aReadyTime);
  void PauseAt(const TimeDuration& aReadyTime);
  void FinishPendingAt(const TimeDuration& aReadyTime) {
    if (mPendingState == PendingState::PlayPending) {
      ResumeAt(aReadyTime);
    } else if (mPendingState == PendingState::PausePending) {
      PauseAt(aReadyTime);
    } else {
      NS_NOTREACHED("Can't finish pending if we're not in a pending state");
    }
  }
  void ApplyPendingPlaybackRate() {
    if (mPendingPlaybackRate) {
      mPlaybackRate = *mPendingPlaybackRate;
      mPendingPlaybackRate.reset();
    }
  }

  /**
   * Finishing behavior depends on if changes to timing occurred due
   * to a seek or regular playback.
   */
  enum class SeekFlag { NoSeek, DidSeek };

  enum class SyncNotifyFlag { Sync, Async };

  virtual void UpdateTiming(SeekFlag aSeekFlag, SyncNotifyFlag aSyncNotifyFlag);
  void UpdateFinishedState(SeekFlag aSeekFlag, SyncNotifyFlag aSyncNotifyFlag);
  void UpdateEffect();
  void FlushStyle() const;
  void PostUpdate();
  void ResetFinishedPromise();
  void MaybeResolveFinishedPromise();
  void DoFinishNotification(SyncNotifyFlag aSyncNotifyFlag);
  friend class AsyncFinishNotification;
  void DoFinishNotificationImmediately(MicroTaskRunnable* aAsync = nullptr);
  void DispatchPlaybackEvent(const nsAString& aName);

  /**
   * Remove this animation from the pending animation tracker and reset
   * mPendingState as necessary. The caller is responsible for resolving or
   * aborting the mReady promise as necessary.
   */
  void CancelPendingTasks();

  /**
   * Performs the same steps as CancelPendingTasks and also rejects and
   * recreates the ready promise if the animation was pending.
   */
  void ResetPendingTasks();

  /**
   * Returns true if this animation is not only play-pending, but has
   * yet to be given a pending ready time. This roughly corresponds to
   * animations that are waiting to be painted (since we set the pending
   * ready time at the end of painting). Identifying such animations is
   * useful because in some cases animations that are painted together
   * may need to be synchronized.
   *
   * We don't, however, want to include animations with a fixed start time such
   * as animations that are simply having their playbackRate updated or which
   * are resuming from an aborted pause.
   */
  bool IsNewlyStarted() const {
    return mPendingState == PendingState::PlayPending &&
           mPendingReadyTime.IsNull() && mStartTime.IsNull();
  }
  bool IsPossiblyOrphanedPendingAnimation() const;
  StickyTimeDuration EffectEnd() const;

  Nullable<TimeDuration> GetCurrentTimeForHoldTime(
      const Nullable<TimeDuration>& aHoldTime) const;
  Nullable<TimeDuration> GetUnconstrainedCurrentTime() const {
    return GetCurrentTimeForHoldTime(Nullable<TimeDuration>());
  }

  nsIDocument* GetRenderedDocument() const;

  RefPtr<AnimationTimeline> mTimeline;
  RefPtr<AnimationEffectReadOnly> mEffect;
  // The beginning of the delay period.
  Nullable<TimeDuration> mStartTime;            // Timeline timescale
  Nullable<TimeDuration> mHoldTime;             // Animation timescale
  Nullable<TimeDuration> mPendingReadyTime;     // Timeline timescale
  Nullable<TimeDuration> mPreviousCurrentTime;  // Animation timescale
  double mPlaybackRate;
  Maybe<double> mPendingPlaybackRate;

  // A Promise that is replaced on each call to Play()
  // and fulfilled when Play() is successfully completed.
  // This object is lazily created by GetReady.
  // See http://drafts.csswg.org/web-animations/#current-ready-promise
  RefPtr<Promise> mReady;

  // A Promise that is resolved when we reach the end of the effect, or
  // 0 when playing backwards. The Promise is replaced if the animation is
  // finished but then a state change makes it not finished.
  // This object is lazily created by GetFinished.
  // See http://drafts.csswg.org/web-animations/#current-finished-promise
  RefPtr<Promise> mFinished;

  // Indicates if the animation is in the pending state (and what state it is
  // waiting to enter when it finished pending). We use this rather than
  // checking if this animation is tracked by a PendingAnimationTracker because
  // the animation will continue to be pending even after it has been removed
  // from the PendingAnimationTracker while it is waiting for the next tick
  // (see TriggerOnNextTick for details).
  enum class PendingState { NotPending, PlayPending, PausePending };
  PendingState mPendingState;

  static uint64_t sNextAnimationIndex;

  // The relative position of this animation within the global animation list.
  // This is kNoIndex while the animation is in the idle state and is updated
  // each time the animation transitions out of the idle state.
  //
  // Note that subclasses such as CSSTransition and CSSAnimation may repurpose
  // this member to implement their own brand of sorting. As a result, it is
  // possible for two different objects to have the same index.
  uint64_t mAnimationIndex;

  bool mFinishedAtLastComposeStyle;
  // Indicates that the animation should be exposed in an element's
  // getAnimations() list.
  bool mIsRelevant;

  RefPtr<MicroTaskRunnable> mFinishNotificationTask;
  // True if mFinished is resolved or would be resolved if mFinished has
  // yet to be created. This is not set when mFinished is rejected since
  // in that case mFinished is immediately reset to represent a new current
  // finished promise.
  bool mFinishedIsResolved;

  // True if this animation was triggered at the same time as one or more
  // geometric animations and hence we should run any transform animations on
  // the main thread.
  bool mSyncWithGeometricAnimations;

  nsString mId;
};

}  // namespace dom
}  // namespace mozilla

#endif  // mozilla_dom_Animation_h