layout/style/nsTransitionManager.h

   1 /* vim: set shiftwidth=2 tabstop=8 autoindent cindent expandtab: */
   2 /* This Source Code Form is subject to the terms of the Mozilla Public
   3  * License, v. 2.0. If a copy of the MPL was not distributed with this
   4  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   5
   6 /* Code to start and animate CSS transitions. */
   7
   8 #ifndef nsTransitionManager_h_
   9 #define nsTransitionManager_h_
  10
  11 #include "mozilla/Attributes.h"
  12 #include "mozilla/MemoryReporting.h"
  13 #include "mozilla/dom/Animation.h"
  14 #include "mozilla/dom/AnimationPlayer.h"
  15 #include "AnimationCommon.h"
  16 #include "nsCSSPseudoElements.h"
  17
  18 class nsStyleContext;
  19 class nsPresContext;
  20 class nsCSSPropertySet;
  21 struct ElementDependentRuleProcessorData;
  22
  23 namespace mozilla {
  24 struct StyleTransition;
  25 }
  26
  27 /*****************************************************************************
  28  * Per-Element data                                                          *
  29  *****************************************************************************/
  30
  31 namespace mozilla {
  32
  33 struct ElementPropertyTransition : public dom::Animation
  34 {
  35   ElementPropertyTransition(nsIDocument* aDocument,
  36                             dom::Element* aTarget,
  37                             nsCSSPseudoElements::Type aPseudoType,
  38                             const AnimationTiming &aTiming)
  39     : dom::Animation(aDocument, aTarget, aPseudoType, aTiming, EmptyString())
  40   { }
  41
  42   virtual ElementPropertyTransition* AsTransition() { return this; }
  43   virtual const ElementPropertyTransition* AsTransition() const { return this; }
  44
  45   // This is the start value to be used for a check for whether a
  46   // transition is being reversed.  Normally the same as
  47   // mProperties[0].mSegments[0].mFromValue, except when this transition
  48   // started as the reversal of another in-progress transition.
  49   // Needed so we can handle two reverses in a row.
  50   mozilla::StyleAnimationValue mStartForReversingTest;
  51   // Likewise, the portion (in value space) of the "full" reversed
  52   // transition that we're actually covering.  For example, if a :hover
  53   // effect has a transition that moves the element 10px to the right
  54   // (by changing 'left' from 0px to 10px), and the mouse moves in to
  55   // the element (starting the transition) but then moves out after the
  56   // transition has advanced 4px, the second transition (from 10px/4px
  57   // to 0px) will have mReversePortion of 0.4.  (If the mouse then moves
  58   // in again when the transition is back to 2px, the mReversePortion
  59   // for the third transition (from 0px/2px to 10px) will be 0.8.
  60   double mReversePortion;
  61
  62   // Compute the portion of the *value* space that we should be through
  63   // at the current time.  (The input to the transition timing function
  64   // has time units, the output has value units.)
  65   double CurrentValuePortion() const;
  66 };
  67
  68 class CSSTransitionPlayer MOZ_FINAL : public dom::AnimationPlayer
  69 {
  70 public:
  71  explicit CSSTransitionPlayer(dom::AnimationTimeline* aTimeline)
  72     : dom::AnimationPlayer(aTimeline)
  73   {
  74   }
  75
  76   virtual CSSTransitionPlayer*
  77   AsCSSTransitionPlayer() MOZ_OVERRIDE { return this; }
  78
  79   virtual dom::AnimationPlayState PlayStateFromJS() const MOZ_OVERRIDE;
  80   virtual void PlayFromJS() MOZ_OVERRIDE;
  81
  82   // A variant of Play() that avoids posting style updates since this method
  83   // is expected to be called whilst already updating style.
  84   void PlayFromStyle() { DoPlay(); }
  85
  86 protected:
  87   virtual ~CSSTransitionPlayer() { }
  88
  89   virtual css::CommonAnimationManager* GetAnimationManager() const MOZ_OVERRIDE;
  90 };
  91
  92 } // namespace mozilla
  93
  94 class nsTransitionManager MOZ_FINAL
  95   : public mozilla::css::CommonAnimationManager
  96 {
  97 public:
  98   explicit nsTransitionManager(nsPresContext *aPresContext)
  99     : mozilla::css::CommonAnimationManager(aPresContext)
 100     , mInAnimationOnlyStyleUpdate(false)
 101   {
 102   }
 103
 104   typedef mozilla::AnimationPlayerCollection AnimationPlayerCollection;
 105
 106   static AnimationPlayerCollection*
 107   GetAnimationsForCompositor(nsIContent* aContent, nsCSSProperty aProperty)
 108   {
 109     return mozilla::css::CommonAnimationManager::GetAnimationsForCompositor(
 110       aContent, nsGkAtoms::transitionsProperty, aProperty);
 111   }
 112
 113   /**
 114    * StyleContextChanged
 115    *
 116    * To be called from nsFrameManager::ReResolveStyleContext when the
 117    * style of an element has changed, to initiate transitions from
 118    * that style change.  For style contexts with :before and :after
 119    * pseudos, aElement is expected to be the generated before/after
 120    * element.
 121    *
 122    * It may return a "cover rule" (see CoverTransitionStartStyleRule) to
 123    * cover up some of the changes for the duration of the restyling of
 124    * descendants.  If it does, this function will take care of causing
 125    * the necessary restyle afterwards, but the caller must restyle the
 126    * element *again* with the original sequence of rules plus the
 127    * returned cover rule as the most specific rule.
 128    */
 129   already_AddRefed<nsIStyleRule>
 130     StyleContextChanged(mozilla::dom::Element *aElement,
 131                         nsStyleContext *aOldStyleContext,
 132                         nsStyleContext *aNewStyleContext);
 133
 134   void SetInAnimationOnlyStyleUpdate(bool aInAnimationOnlyUpdate) {
 135     mInAnimationOnlyStyleUpdate = aInAnimationOnlyUpdate;
 136   }
 137
 138   virtual size_t SizeOfExcludingThis(mozilla::MallocSizeOf aMallocSizeOf) const
 139     MOZ_MUST_OVERRIDE MOZ_OVERRIDE;
 140   virtual size_t SizeOfIncludingThis(mozilla::MallocSizeOf aMallocSizeOf) const
 141     MOZ_MUST_OVERRIDE MOZ_OVERRIDE;
 142
 143   // nsARefreshObserver
 144   virtual void WillRefresh(mozilla::TimeStamp aTime) MOZ_OVERRIDE;
 145
 146   void FlushTransitions(FlushFlags aFlags);
 147
 148 protected:
 149   virtual nsIAtom* GetAnimationsAtom() MOZ_OVERRIDE {
 150     return nsGkAtoms::transitionsProperty;
 151   }
 152   virtual nsIAtom* GetAnimationsBeforeAtom() MOZ_OVERRIDE {
 153     return nsGkAtoms::transitionsOfBeforeProperty;
 154   }
 155   virtual nsIAtom* GetAnimationsAfterAtom() MOZ_OVERRIDE {
 156     return nsGkAtoms::transitionsOfAfterProperty;
 157   }
 158
 159 private:
 160   void
 161   ConsiderStartingTransition(nsCSSProperty aProperty,
 162                              const mozilla::StyleTransition& aTransition,
 163                              mozilla::dom::Element* aElement,
 164                              AnimationPlayerCollection*& aElementTransitions,
 165                              nsStyleContext* aOldStyleContext,
 166                              nsStyleContext* aNewStyleContext,
 167                              bool* aStartedAny,
 168                              nsCSSPropertySet* aWhichStarted);
 169
 170   bool mInAnimationOnlyStyleUpdate;
 171 };
 172
 173 #endif /* !defined(nsTransitionManager_h_) */