gecko/layout/style/nsTransitionManager.h
L. David Baron 2999d152c3 Bug 822721: Call CalcStyleDifference and process the style change list resulting from the miniflush we do to update throttled animations prior to seeing if we need to start transitions. r=bzbarsky
The CalcStyleDifference call is absolutely necessary even if we didn't
need to process the change list, because it causes the new style
context to have cached structs that we might need for a later
comparison.  This is important because, as an optimization, we only
compare structs that have been retrieved.  This optimization requires
that when we replace a style context, we fetch all the structs on the
new style context that had been fetched on the old style context (which
is normally necessary anyway in order to do comparison so we can process
the changes appropriately).

However, actually processing the change list is also necessary to fix
the bug; it's the actual change from the miniflush that matters here.
Based on dholbert's debugging information, I think it's mostly likely
because we were failing to process the UpdateOverflow hint.
2013-01-08 20:37:29 -08:00

234 lines
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/* 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/. */
/* Code to start and animate CSS transitions. */
#ifndef nsTransitionManager_h_
#define nsTransitionManager_h_
#include "mozilla/Attributes.h"
#include "AnimationCommon.h"
#include "nsCSSPseudoElements.h"
class nsStyleContext;
class nsPresContext;
class nsCSSPropertySet;
struct nsTransition;
struct ElementDependentRuleProcessorData;
/*****************************************************************************
* Per-Element data *
*****************************************************************************/
struct ElementPropertyTransition
{
ElementPropertyTransition()
: mIsRunningOnCompositor(false)
{}
nsCSSProperty mProperty;
nsStyleAnimation::Value mStartValue, mEndValue;
mozilla::TimeStamp mStartTime; // actual start plus transition delay
// data from the relevant nsTransition
mozilla::TimeDuration mDuration;
mozilla::css::ComputedTimingFunction mTimingFunction;
// This is the start value to be used for a check for whether a
// transition is being reversed. Normally the same as mStartValue,
// except when this transition started as the reversal of another
// in-progress transition. Needed so we can handle two reverses in a
// row.
nsStyleAnimation::Value mStartForReversingTest;
// Likewise, the portion (in value space) of the "full" reversed
// transition that we're actually covering. For example, if a :hover
// effect has a transition that moves the element 10px to the right
// (by changing 'left' from 0px to 10px), and the mouse moves in to
// the element (starting the transition) but then moves out after the
// transition has advanced 4px, the second transition (from 10px/4px
// to 0px) will have mReversePortion of 0.4. (If the mouse then moves
// in again when the transition is back to 2px, the mReversePortion
// for the third transition (from 0px/2px to 10px) will be 0.8.
double mReversePortion;
// true when the transition is running on the compositor. In particular,
// mIsRunningOnCompositor will be false if the transition has a delay and we
// are not yet at mStartTime, so there is no animation on the layer.
bool mIsRunningOnCompositor;
// Compute the portion of the *value* space that we should be through
// at the given time. (The input to the transition timing function
// has time units, the output has value units.)
double ValuePortionFor(mozilla::TimeStamp aRefreshTime) const;
bool IsRemovedSentinel() const
{
return mStartTime.IsNull();
}
void SetRemovedSentinel()
{
// assign the null time stamp
mStartTime = mozilla::TimeStamp();
}
bool IsRunningAt(mozilla::TimeStamp aTime) const;
};
struct ElementTransitions MOZ_FINAL
: public mozilla::css::CommonElementAnimationData
{
ElementTransitions(mozilla::dom::Element *aElement, nsIAtom *aElementProperty,
nsTransitionManager *aTransitionManager,
mozilla::TimeStamp aNow);
void EnsureStyleRuleFor(mozilla::TimeStamp aRefreshTime);
virtual bool HasAnimationOfProperty(nsCSSProperty aProperty) const MOZ_OVERRIDE;
virtual bool CanPerformOnCompositorThread(CanAnimateFlags aFlags) const MOZ_OVERRIDE;
// Either zero or one for each CSS property:
nsTArray<ElementPropertyTransition> mPropertyTransitions;
// Generation counter for flushes of throttled transitions.
// Used to prevent updating the styles twice for a given element during
// UpdateAllThrottledStyles.
mozilla::TimeStamp mFlushGeneration;
};
class nsTransitionManager : public mozilla::css::CommonAnimationManager
{
public:
nsTransitionManager(nsPresContext *aPresContext)
: mozilla::css::CommonAnimationManager(aPresContext)
{
}
static ElementTransitions* GetTransitions(nsIContent* aContent) {
return static_cast<ElementTransitions*>
(aContent->GetProperty(nsGkAtoms::transitionsProperty));
}
// Returns true if aContent or any of its ancestors has a transition.
static bool ContentOrAncestorHasTransition(nsIContent* aContent) {
do {
if (GetTransitions(aContent)) {
return true;
}
} while ((aContent = aContent->GetParent()));
return false;
}
typedef mozilla::css::CommonElementAnimationData CommonElementAnimationData;
static ElementTransitions*
GetTransitionsForCompositor(nsIContent* aContent,
nsCSSProperty aProperty)
{
if (!aContent->MayHaveAnimations()) {
return nullptr;
}
ElementTransitions* transitions = GetTransitions(aContent);
if (!transitions ||
!transitions->HasAnimationOfProperty(aProperty) ||
!transitions->CanPerformOnCompositorThread(
CommonElementAnimationData::CanAnimate_AllowPartial)) {
return nullptr;
}
return transitions;
}
/**
* StyleContextChanged
*
* To be called from nsFrameManager::ReResolveStyleContext when the
* style of an element has changed, to initiate transitions from
* that style change. For style contexts with :before and :after
* pseudos, aElement is expected to be the generated before/after
* element.
*
* It may return a "cover rule" (see CoverTransitionStartStyleRule) to
* cover up some of the changes for the duration of the restyling of
* descendants. If it does, this function will take care of causing
* the necessary restyle afterwards, but the caller must restyle the
* element *again* with the original sequence of rules plus the
* returned cover rule as the most specific rule.
*/
already_AddRefed<nsIStyleRule>
StyleContextChanged(mozilla::dom::Element *aElement,
nsStyleContext *aOldStyleContext,
nsStyleContext *aNewStyleContext);
// nsIStyleRuleProcessor (parts)
virtual void RulesMatching(ElementRuleProcessorData* aData) MOZ_OVERRIDE;
virtual void RulesMatching(PseudoElementRuleProcessorData* aData) MOZ_OVERRIDE;
virtual void RulesMatching(AnonBoxRuleProcessorData* aData) MOZ_OVERRIDE;
#ifdef MOZ_XUL
virtual void RulesMatching(XULTreeRuleProcessorData* aData) MOZ_OVERRIDE;
#endif
virtual NS_MUST_OVERRIDE size_t
SizeOfExcludingThis(nsMallocSizeOfFun aMallocSizeOf) const MOZ_OVERRIDE;
virtual NS_MUST_OVERRIDE size_t
SizeOfIncludingThis(nsMallocSizeOfFun aMallocSizeOf) const MOZ_OVERRIDE;
// nsARefreshObserver
virtual void WillRefresh(mozilla::TimeStamp aTime) MOZ_OVERRIDE;
void FlushTransitions(FlushFlags aFlags);
// Performs a 'mini-flush' to make styles from throttled transitions
// up-to-date prior to processing an unrelated style change, so that
// any transitions triggered by that style change produce correct
// results.
//
// In more detail: when we're able to run animations on the
// compositor, we sometimes "throttle" these animations by skipping
// updating style data on the main thread. However, whenever we
// process a normal (non-animation) style change, any changes in
// computed style on elements that have transition-* properties set
// may need to trigger new transitions; this process requires knowing
// both the old and new values of the property. To do this correctly,
// we need to have an up-to-date *old* value of the property on the
// primary frame. So the purpose of the mini-flush is to update the
// style for all throttled transitions and animations to the current
// animation state without making any other updates, so that when we
// process the queued style updates we'll have correct old data to
// compare against. When we do this, we don't bother touching frames
// other than primary frames.
void UpdateAllThrottledStyles();
private:
void ConsiderStartingTransition(nsCSSProperty aProperty,
const nsTransition& aTransition,
mozilla::dom::Element *aElement,
ElementTransitions *&aElementTransitions,
nsStyleContext *aOldStyleContext,
nsStyleContext *aNewStyleContext,
bool *aStartedAny,
nsCSSPropertySet *aWhichStarted);
ElementTransitions* GetElementTransitions(mozilla::dom::Element *aElement,
nsCSSPseudoElements::Type aPseudoType,
bool aCreateIfNeeded);
void WalkTransitionRule(ElementDependentRuleProcessorData* aData,
nsCSSPseudoElements::Type aPseudoType);
// Update the animated styles of an element and its descendants.
// If the element has a transition, it is flushed back to its primary frame.
// If the element does not have a transition, then its style is reparented.
void UpdateThrottledStylesForSubtree(nsIContent* aContent,
nsStyleContext* aParentStyle,
nsStyleChangeList &aChangeList);
// Update the style on aElement from the transition stored in this manager and
// the new parent style - aParentStyle. aElement must be transitioning or
// animated. Returns the updated style.
nsStyleContext* UpdateThrottledStyle(mozilla::dom::Element* aElement,
nsStyleContext* aParentStyle,
nsStyleChangeList &aChangeList);
};
#endif /* !defined(nsTransitionManager_h_) */