1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/layout/style/nsTransitionManager.h Wed Dec 31 06:09:35 2014 +0100
1.3 @@ -0,0 +1,227 @@
1.4 +/* vim: set shiftwidth=2 tabstop=8 autoindent cindent expandtab: */
1.5 +/* This Source Code Form is subject to the terms of the Mozilla Public
1.6 + * License, v. 2.0. If a copy of the MPL was not distributed with this
1.7 + * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
1.8 +
1.9 +/* Code to start and animate CSS transitions. */
1.10 +
1.11 +#ifndef nsTransitionManager_h_
1.12 +#define nsTransitionManager_h_
1.13 +
1.14 +#include "mozilla/Attributes.h"
1.15 +#include "mozilla/MemoryReporting.h"
1.16 +#include "AnimationCommon.h"
1.17 +#include "nsCSSPseudoElements.h"
1.18 +
1.19 +class nsStyleContext;
1.20 +class nsPresContext;
1.21 +class nsCSSPropertySet;
1.22 +struct nsTransition;
1.23 +struct ElementDependentRuleProcessorData;
1.24 +
1.25 +/*****************************************************************************
1.26 + * Per-Element data *
1.27 + *****************************************************************************/
1.28 +
1.29 +struct ElementPropertyTransition : public mozilla::StyleAnimation
1.30 +{
1.31 + // This is the start value to be used for a check for whether a
1.32 + // transition is being reversed. Normally the same as
1.33 + // mProperties[0].mSegments[0].mFromValue, except when this transition
1.34 + // started as the reversal of another in-progress transition.
1.35 + // Needed so we can handle two reverses in a row.
1.36 + nsStyleAnimation::Value mStartForReversingTest;
1.37 + // Likewise, the portion (in value space) of the "full" reversed
1.38 + // transition that we're actually covering. For example, if a :hover
1.39 + // effect has a transition that moves the element 10px to the right
1.40 + // (by changing 'left' from 0px to 10px), and the mouse moves in to
1.41 + // the element (starting the transition) but then moves out after the
1.42 + // transition has advanced 4px, the second transition (from 10px/4px
1.43 + // to 0px) will have mReversePortion of 0.4. (If the mouse then moves
1.44 + // in again when the transition is back to 2px, the mReversePortion
1.45 + // for the third transition (from 0px/2px to 10px) will be 0.8.
1.46 + double mReversePortion;
1.47 +
1.48 + // Compute the portion of the *value* space that we should be through
1.49 + // at the given time. (The input to the transition timing function
1.50 + // has time units, the output has value units.)
1.51 + double ValuePortionFor(mozilla::TimeStamp aRefreshTime) const;
1.52 +
1.53 + bool IsRemovedSentinel() const
1.54 + {
1.55 + // Note that mozilla::StyleAnimation::IsRunningAt depends on removed
1.56 + // sentinels being represented by a null mStartTime.
1.57 + return mStartTime.IsNull();
1.58 + }
1.59 +
1.60 + void SetRemovedSentinel()
1.61 + {
1.62 + // assign the null time stamp
1.63 + mStartTime = mozilla::TimeStamp();
1.64 + }
1.65 +};
1.66 +
1.67 +struct ElementTransitions MOZ_FINAL
1.68 + : public mozilla::css::CommonElementAnimationData
1.69 +{
1.70 + ElementTransitions(mozilla::dom::Element *aElement, nsIAtom *aElementProperty,
1.71 + nsTransitionManager *aTransitionManager,
1.72 + mozilla::TimeStamp aNow);
1.73 +
1.74 + void EnsureStyleRuleFor(mozilla::TimeStamp aRefreshTime);
1.75 +
1.76 + virtual bool HasAnimationOfProperty(nsCSSProperty aProperty) const MOZ_OVERRIDE;
1.77 +
1.78 + // If aFlags contains CanAnimate_AllowPartial, returns whether the
1.79 + // state of this element's transitions at the current refresh driver
1.80 + // time contains transition data that can be done on the compositor
1.81 + // thread. (This is useful for determining whether a layer should be
1.82 + // active, or whether to send data to the layer.)
1.83 + // If aFlags does not contain CanAnimate_AllowPartial, returns whether
1.84 + // the state of this element's transitions at the current refresh driver
1.85 + // time can be fully represented by data sent to the compositor.
1.86 + // (This is useful for determining whether throttle the transition
1.87 + // (suppress main-thread style updates).)
1.88 + // Note that when CanPerformOnCompositorThread returns true, it also,
1.89 + // as a side-effect, notifies the ActiveLayerTracker. FIXME: This
1.90 + // should probably move to the relevant callers.
1.91 + virtual bool CanPerformOnCompositorThread(CanAnimateFlags aFlags) const MOZ_OVERRIDE;
1.92 +
1.93 + // Either zero or one for each CSS property:
1.94 + nsTArray<ElementPropertyTransition> mPropertyTransitions;
1.95 +};
1.96 +
1.97 +
1.98 +
1.99 +class nsTransitionManager MOZ_FINAL
1.100 + : public mozilla::css::CommonAnimationManager
1.101 +{
1.102 +public:
1.103 + nsTransitionManager(nsPresContext *aPresContext)
1.104 + : mozilla::css::CommonAnimationManager(aPresContext)
1.105 + {
1.106 + }
1.107 +
1.108 + static ElementTransitions* GetTransitions(nsIContent* aContent) {
1.109 + return static_cast<ElementTransitions*>
1.110 + (aContent->GetProperty(nsGkAtoms::transitionsProperty));
1.111 + }
1.112 +
1.113 + // Returns true if aContent or any of its ancestors has a transition.
1.114 + static bool ContentOrAncestorHasTransition(nsIContent* aContent) {
1.115 + do {
1.116 + if (GetTransitions(aContent)) {
1.117 + return true;
1.118 + }
1.119 + } while ((aContent = aContent->GetParent()));
1.120 +
1.121 + return false;
1.122 + }
1.123 +
1.124 + typedef mozilla::css::CommonElementAnimationData CommonElementAnimationData;
1.125 +
1.126 + static ElementTransitions*
1.127 + GetTransitionsForCompositor(nsIContent* aContent,
1.128 + nsCSSProperty aProperty)
1.129 + {
1.130 + if (!aContent->MayHaveAnimations()) {
1.131 + return nullptr;
1.132 + }
1.133 + ElementTransitions* transitions = GetTransitions(aContent);
1.134 + if (!transitions ||
1.135 + !transitions->HasAnimationOfProperty(aProperty) ||
1.136 + !transitions->CanPerformOnCompositorThread(
1.137 + CommonElementAnimationData::CanAnimate_AllowPartial)) {
1.138 + return nullptr;
1.139 + }
1.140 + return transitions;
1.141 + }
1.142 +
1.143 + /**
1.144 + * StyleContextChanged
1.145 + *
1.146 + * To be called from nsFrameManager::ReResolveStyleContext when the
1.147 + * style of an element has changed, to initiate transitions from
1.148 + * that style change. For style contexts with :before and :after
1.149 + * pseudos, aElement is expected to be the generated before/after
1.150 + * element.
1.151 + *
1.152 + * It may return a "cover rule" (see CoverTransitionStartStyleRule) to
1.153 + * cover up some of the changes for the duration of the restyling of
1.154 + * descendants. If it does, this function will take care of causing
1.155 + * the necessary restyle afterwards, but the caller must restyle the
1.156 + * element *again* with the original sequence of rules plus the
1.157 + * returned cover rule as the most specific rule.
1.158 + */
1.159 + already_AddRefed<nsIStyleRule>
1.160 + StyleContextChanged(mozilla::dom::Element *aElement,
1.161 + nsStyleContext *aOldStyleContext,
1.162 + nsStyleContext *aNewStyleContext);
1.163 +
1.164 + // nsIStyleRuleProcessor (parts)
1.165 + virtual void RulesMatching(ElementRuleProcessorData* aData) MOZ_OVERRIDE;
1.166 + virtual void RulesMatching(PseudoElementRuleProcessorData* aData) MOZ_OVERRIDE;
1.167 + virtual void RulesMatching(AnonBoxRuleProcessorData* aData) MOZ_OVERRIDE;
1.168 +#ifdef MOZ_XUL
1.169 + virtual void RulesMatching(XULTreeRuleProcessorData* aData) MOZ_OVERRIDE;
1.170 +#endif
1.171 + virtual size_t SizeOfExcludingThis(mozilla::MallocSizeOf aMallocSizeOf) const
1.172 + MOZ_MUST_OVERRIDE MOZ_OVERRIDE;
1.173 + virtual size_t SizeOfIncludingThis(mozilla::MallocSizeOf aMallocSizeOf) const
1.174 + MOZ_MUST_OVERRIDE MOZ_OVERRIDE;
1.175 +
1.176 + // nsARefreshObserver
1.177 + virtual void WillRefresh(mozilla::TimeStamp aTime) MOZ_OVERRIDE;
1.178 +
1.179 + void FlushTransitions(FlushFlags aFlags);
1.180 +
1.181 + // Performs a 'mini-flush' to make styles from throttled transitions
1.182 + // up-to-date prior to processing an unrelated style change, so that
1.183 + // any transitions triggered by that style change produce correct
1.184 + // results.
1.185 + //
1.186 + // In more detail: when we're able to run animations on the
1.187 + // compositor, we sometimes "throttle" these animations by skipping
1.188 + // updating style data on the main thread. However, whenever we
1.189 + // process a normal (non-animation) style change, any changes in
1.190 + // computed style on elements that have transition-* properties set
1.191 + // may need to trigger new transitions; this process requires knowing
1.192 + // both the old and new values of the property. To do this correctly,
1.193 + // we need to have an up-to-date *old* value of the property on the
1.194 + // primary frame. So the purpose of the mini-flush is to update the
1.195 + // style for all throttled transitions and animations to the current
1.196 + // animation state without making any other updates, so that when we
1.197 + // process the queued style updates we'll have correct old data to
1.198 + // compare against. When we do this, we don't bother touching frames
1.199 + // other than primary frames.
1.200 + void UpdateAllThrottledStyles();
1.201 +
1.202 + ElementTransitions* GetElementTransitions(mozilla::dom::Element *aElement,
1.203 + nsCSSPseudoElements::Type aPseudoType,
1.204 + bool aCreateIfNeeded);
1.205 +
1.206 +protected:
1.207 + virtual void ElementDataRemoved() MOZ_OVERRIDE;
1.208 + virtual void AddElementData(mozilla::css::CommonElementAnimationData* aData) MOZ_OVERRIDE;
1.209 +
1.210 +private:
1.211 + void ConsiderStartingTransition(nsCSSProperty aProperty,
1.212 + const nsTransition& aTransition,
1.213 + mozilla::dom::Element *aElement,
1.214 + ElementTransitions *&aElementTransitions,
1.215 + nsStyleContext *aOldStyleContext,
1.216 + nsStyleContext *aNewStyleContext,
1.217 + bool *aStartedAny,
1.218 + nsCSSPropertySet *aWhichStarted);
1.219 + void WalkTransitionRule(ElementDependentRuleProcessorData* aData,
1.220 + nsCSSPseudoElements::Type aPseudoType);
1.221 + // Update the animated styles of an element and its descendants.
1.222 + // If the element has a transition, it is flushed back to its primary frame.
1.223 + // If the element does not have a transition, then its style is reparented.
1.224 + void UpdateThrottledStylesForSubtree(nsIContent* aContent,
1.225 + nsStyleContext* aParentStyle,
1.226 + nsStyleChangeList &aChangeList);
1.227 + void UpdateAllThrottledStylesInternal();
1.228 +};
1.229 +
1.230 +#endif /* !defined(nsTransitionManager_h_) */
