gecko-dev/layout/style/AnimationCommon.h

/* vim: set shiftwidth=2 tabstop=8 autoindent cindent expandtab: */
/* 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_css_AnimationCommon_h
#define mozilla_css_AnimationCommon_h

#include "nsIStyleRuleProcessor.h"
#include "nsIStyleRule.h"
#include "nsRefreshDriver.h"
#include "prclist.h"
#include "nsCSSProperty.h"
#include "mozilla/MemoryReporting.h"
#include "mozilla/StyleAnimationValue.h"
#include "mozilla/dom/AnimationPlayer.h"
#include "mozilla/dom/Element.h"
#include "mozilla/dom/Nullable.h"
#include "nsStyleStruct.h"
#include "mozilla/Attributes.h"
#include "mozilla/Assertions.h"
#include "mozilla/FloatingPoint.h"
#include "nsCSSPseudoElements.h"
#include "nsCycleCollectionParticipant.h"

class nsIFrame;
class nsPresContext;
class nsStyleChangeList;

namespace mozilla {

class RestyleTracker;
struct AnimationPlayerCollection;

namespace css {

bool IsGeometricProperty(nsCSSProperty aProperty);

class CommonAnimationManager : public nsIStyleRuleProcessor,
                               public nsARefreshObserver {
public:
  explicit CommonAnimationManager(nsPresContext *aPresContext);

  // nsISupports
  NS_DECL_ISUPPORTS

  // nsIStyleRuleProcessor (parts)
  virtual nsRestyleHint HasStateDependentStyle(StateRuleProcessorData* aData) MOZ_OVERRIDE;
  virtual nsRestyleHint HasStateDependentStyle(PseudoElementStateRuleProcessorData* aData) MOZ_OVERRIDE;
  virtual bool HasDocumentStateDependentStyle(StateRuleProcessorData* aData) MOZ_OVERRIDE;
  virtual nsRestyleHint
    HasAttributeDependentStyle(AttributeRuleProcessorData* aData) MOZ_OVERRIDE;
  virtual bool MediumFeaturesChanged(nsPresContext* aPresContext) MOZ_OVERRIDE;
  virtual size_t SizeOfExcludingThis(mozilla::MallocSizeOf aMallocSizeOf)
    const MOZ_MUST_OVERRIDE MOZ_OVERRIDE;
  virtual size_t SizeOfIncludingThis(mozilla::MallocSizeOf aMallocSizeOf)
    const MOZ_MUST_OVERRIDE MOZ_OVERRIDE;

  /**
   * Notify the manager that the pres context is going away.
   */
  void Disconnect();

  // Tell the restyle tracker about all the styles that we're currently
  // animating, so that it can update the animation rule for these
  // elements.
  void AddStyleUpdatesTo(mozilla::RestyleTracker& aTracker);

  enum FlushFlags {
    Can_Throttle,
    Cannot_Throttle
  };

  static bool ExtractComputedValueForTransition(
                  nsCSSProperty aProperty,
                  nsStyleContext* aStyleContext,
                  mozilla::StyleAnimationValue& aComputedValue);

protected:
  virtual ~CommonAnimationManager();

  // For ElementCollectionRemoved
  friend struct mozilla::AnimationPlayerCollection;

  void AddElementCollection(AnimationPlayerCollection* aCollection);
  void ElementCollectionRemoved() { CheckNeedsRefresh(); }
  void RemoveAllElementCollections();

  // Check to see if we should stop or start observing the refresh driver
  void CheckNeedsRefresh();

  // When this returns a value other than nullptr, it also,
  // as a side-effect, notifies the ActiveLayerTracker.
  static AnimationPlayerCollection*
  GetAnimationsForCompositor(nsIContent* aContent,
                             nsIAtom* aElementProperty,
                             nsCSSProperty aProperty);

  PRCList mElementCollections;
  nsPresContext *mPresContext; // weak (non-null from ctor to Disconnect)
  bool mIsObservingRefreshDriver;
};

/**
 * A style rule that maps property-StyleAnimationValue pairs.
 */
class AnimValuesStyleRule MOZ_FINAL : public nsIStyleRule
{
public:
  // nsISupports implementation
  NS_DECL_ISUPPORTS

  // nsIStyleRule implementation
  virtual void MapRuleInfoInto(nsRuleData* aRuleData) MOZ_OVERRIDE;
#ifdef DEBUG
  virtual void List(FILE* out = stdout, int32_t aIndent = 0) const MOZ_OVERRIDE;
#endif

  void AddValue(nsCSSProperty aProperty,
                mozilla::StyleAnimationValue &aStartValue)
  {
    PropertyValuePair v = { aProperty, aStartValue };
    mPropertyValuePairs.AppendElement(v);
  }

  // Caller must fill in returned value.
  mozilla::StyleAnimationValue* AddEmptyValue(nsCSSProperty aProperty)
  {
    PropertyValuePair *p = mPropertyValuePairs.AppendElement();
    p->mProperty = aProperty;
    return &p->mValue;
  }

  struct PropertyValuePair {
    nsCSSProperty mProperty;
    mozilla::StyleAnimationValue mValue;
  };

private:
  ~AnimValuesStyleRule() {}

  InfallibleTArray<PropertyValuePair> mPropertyValuePairs;
};

} /* end css sub-namespace */

typedef InfallibleTArray<nsRefPtr<dom::AnimationPlayer> >
  AnimationPlayerPtrArray;

enum EnsureStyleRuleFlags {
  EnsureStyleRule_IsThrottled,
  EnsureStyleRule_IsNotThrottled
};

struct AnimationPlayerCollection : public PRCList
{
  AnimationPlayerCollection(dom::Element *aElement, nsIAtom *aElementProperty,
                            mozilla::css::CommonAnimationManager *aManager)
    : mElement(aElement)
    , mElementProperty(aElementProperty)
    , mManager(aManager)
    , mAnimationGeneration(0)
    , mNeedsRefreshes(true)
#ifdef DEBUG
    , mCalledPropertyDtor(false)
#endif
  {
    MOZ_COUNT_CTOR(AnimationPlayerCollection);
    PR_INIT_CLIST(this);
  }
  ~AnimationPlayerCollection()
  {
    NS_ABORT_IF_FALSE(mCalledPropertyDtor,
                      "must call destructor through element property dtor");
    MOZ_COUNT_DTOR(AnimationPlayerCollection);
    PR_REMOVE_LINK(this);
    mManager->ElementCollectionRemoved();
  }

  void Destroy()
  {
    // This will call our destructor.
    mElement->DeleteProperty(mElementProperty);
  }

  static void PropertyDtor(void *aObject, nsIAtom *aPropertyName,
                           void *aPropertyValue, void *aData);

  void Tick();

  void EnsureStyleRuleFor(TimeStamp aRefreshTime, EnsureStyleRuleFlags aFlags);

  bool CanThrottleTransformChanges(mozilla::TimeStamp aTime);

  bool CanThrottleAnimation(mozilla::TimeStamp aTime);

  enum CanAnimateFlags {
    // Testing for width, height, top, right, bottom, or left.
    CanAnimate_HasGeometricProperty = 1,
    // Allow the case where OMTA is allowed in general, but not for the
    // specified property.
    CanAnimate_AllowPartial = 2
  };

  static bool
  CanAnimatePropertyOnCompositor(const dom::Element *aElement,
                                 nsCSSProperty aProperty,
                                 CanAnimateFlags aFlags);

  static bool IsCompositorAnimationDisabledForFrame(nsIFrame* aFrame);

  // True if this animation can be performed on the compositor thread.
  //
  // If aFlags contains CanAnimate_AllowPartial, returns whether the
  // state of this element's animations at the current refresh driver
  // time contains animation data that can be done on the compositor
  // thread.  (This is useful for determining whether a layer should be
  // active, or whether to send data to the layer.)
  //
  // If aFlags does not contain CanAnimate_AllowPartial, returns whether
  // the state of this element's animations at the current refresh driver
  // time can be fully represented by data sent to the compositor.
  // (This is useful for determining whether throttle the animation
  // (suppress main-thread style updates).)
  bool CanPerformOnCompositorThread(CanAnimateFlags aFlags) const;
  bool HasAnimationOfProperty(nsCSSProperty aProperty) const;

  bool IsForElement() const { // rather than for a pseudo-element
    return mElementProperty == nsGkAtoms::animationsProperty ||
           mElementProperty == nsGkAtoms::transitionsProperty;
  }

  bool IsForBeforePseudo() const {
    return mElementProperty == nsGkAtoms::animationsOfBeforeProperty ||
           mElementProperty == nsGkAtoms::transitionsOfBeforeProperty;
  }

  bool IsForAfterPseudo() const {
    return mElementProperty == nsGkAtoms::animationsOfAfterProperty ||
           mElementProperty == nsGkAtoms::transitionsOfAfterProperty;
  }

  bool IsForTransitions() const {
    return mElementProperty == nsGkAtoms::transitionsProperty ||
           mElementProperty == nsGkAtoms::transitionsOfBeforeProperty ||
           mElementProperty == nsGkAtoms::transitionsOfAfterProperty;
  }

  bool IsForAnimations() const {
    return mElementProperty == nsGkAtoms::animationsProperty ||
           mElementProperty == nsGkAtoms::animationsOfBeforeProperty ||
           mElementProperty == nsGkAtoms::animationsOfAfterProperty;
  }

  nsString PseudoElement() const
  {
    if (IsForElement()) {
      return EmptyString();
    }
    if (IsForBeforePseudo()) {
      return NS_LITERAL_STRING("::before");
    }
    MOZ_ASSERT(IsForAfterPseudo(),
               "::before & ::after should be the only pseudo-elements here");
    return NS_LITERAL_STRING("::after");
  }

  mozilla::dom::Element* GetElementToRestyle() const;

  void PostRestyleForAnimation(nsPresContext *aPresContext) {
    mozilla::dom::Element* element = GetElementToRestyle();
    if (element) {
      aPresContext->PresShell()->RestyleForAnimation(element, eRestyle_Self);
    }
  }

  static void LogAsyncAnimationFailure(nsCString& aMessage,
                                       const nsIContent* aContent = nullptr);

  dom::Element *mElement;

  // the atom we use in mElement's prop table (must be a static atom,
  // i.e., in an atom list)
  nsIAtom *mElementProperty;

  mozilla::css::CommonAnimationManager *mManager;

  mozilla::AnimationPlayerPtrArray mPlayers;

  // This style rule contains the style data for currently animating
  // values.  It only matches when styling with animation.  When we
  // style without animation, we need to not use it so that we can
  // detect any new changes; if necessary we restyle immediately
  // afterwards with animation.
  // NOTE: If we don't need to apply any styles, mStyleRule will be
  // null, but mStyleRuleRefreshTime will still be valid.
  nsRefPtr<mozilla::css::AnimValuesStyleRule> mStyleRule;

  // RestyleManager keeps track of the number of animation
  // 'mini-flushes' (see nsTransitionManager::UpdateAllThrottledStyles()).
  // mAnimationGeneration is the sequence number of the last flush where a
  // transition/animation changed.  We keep a similar count on the
  // corresponding layer so we can check that the layer is up to date with
  // the animation manager.
  uint64_t mAnimationGeneration;
  // Update mAnimationGeneration to nsCSSFrameConstructor's count
  void UpdateAnimationGeneration(nsPresContext* aPresContext);

  // Returns true if there is an animation that has yet to finish.
  bool HasCurrentAnimations() const;
  // Returns true if there is an animation of the specified property that
  // has yet to finish.
  bool HasCurrentAnimationsForProperty(nsCSSProperty aProperty) const;

  // The refresh time associated with mStyleRule.
  TimeStamp mStyleRuleRefreshTime;

  // False when we know that our current style rule is valid
  // indefinitely into the future (because all of our animations are
  // either completed or paused).  May be invalidated by a style change.
  bool mNeedsRefreshes;

#ifdef DEBUG
  bool mCalledPropertyDtor;
#endif
};

}

#endif /* !defined(mozilla_css_AnimationCommon_h) */