gecko/layout/style/nsTransitionManager.cpp
2009-12-10 18:28:08 -08:00

837 lines
28 KiB
C++

/* vim: set shiftwidth=2 tabstop=8 autoindent cindent expandtab: */
/* ***** BEGIN LICENSE BLOCK *****
* Version: MPL 1.1/GPL 2.0/LGPL 2.1
*
* The contents of this file are subject to the Mozilla Public License Version
* 1.1 (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
* http://www.mozilla.org/MPL/
*
* Software distributed under the License is distributed on an "AS IS" basis,
* WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
* for the specific language governing rights and limitations under the
* License.
*
* The Original Code is nsTransitionManager.
*
* The Initial Developer of the Original Code is the Mozilla Foundation.
* Portions created by the Initial Developer are Copyright (C) 2009
* the Initial Developer. All Rights Reserved.
*
* Contributor(s):
* L. David Baron <dbaron@dbaron.org>, Mozilla Corporation (original author)
*
* Alternatively, the contents of this file may be used under the terms of
* either the GNU General Public License Version 2 or later (the "GPL"), or
* the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
* in which case the provisions of the GPL or the LGPL are applicable instead
* of those above. If you wish to allow use of your version of this file only
* under the terms of either the GPL or the LGPL, and not to allow others to
* use your version of this file under the terms of the MPL, indicate your
* decision by deleting the provisions above and replace them with the notice
* and other provisions required by the GPL or the LGPL. If you do not delete
* the provisions above, a recipient may use your version of this file under
* the terms of any one of the MPL, the GPL or the LGPL.
*
* ***** END LICENSE BLOCK ***** */
/* Code to start and animate CSS transitions. */
#include "nsTransitionManager.h"
#include "nsIContent.h"
#include "nsStyleContext.h"
#include "nsCSSProps.h"
#include "mozilla/TimeStamp.h"
#include "nsRefreshDriver.h"
#include "nsRuleProcessorData.h"
#include "nsIStyleRule.h"
#include "nsRuleWalker.h"
#include "nsRuleData.h"
#include "nsSMILKeySpline.h"
#include "gfxColor.h"
#include "nsCSSPseudoElements.h"
#include "nsCSSPropertySet.h"
#include "nsStyleAnimation.h"
#include "nsCSSDataBlock.h"
using mozilla::TimeStamp;
using mozilla::TimeDuration;
/*****************************************************************************
* Per-Element data *
*****************************************************************************/
struct ElementPropertyTransition
{
nsCSSProperty mProperty;
// We need to have mCurrentValue as a member of this structure because
// the result of the calls to |Interpolate| might hold data that this
// object's owning style rule needs to keep alive (after calling
// UncomputeValue on it in MapRuleInfoInto).
nsStyleAnimation::Value mStartValue, mEndValue, mCurrentValue;
TimeStamp mStartTime; // actual start plus transition delay
// data from the relevant nsTransition
TimeDuration mDuration;
nsSMILKeySpline mTimingFunction;
};
/**
* An ElementTransitionsStyleRule overrides style data with the
* currently-transitioning value for an element that is executing a
* transition. 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.
*/
class ElementTransitionsStyleRule : public nsIStyleRule
{
public:
// nsISupportsImplementation
NS_DECL_ISUPPORTS
// nsIStyleRule implementation
NS_IMETHOD MapRuleInfoInto(nsRuleData* aRuleData);
#ifdef DEBUG
NS_IMETHOD List(FILE* out = stdout, PRInt32 aIndent = 0) const;
#endif
ElementTransitionsStyleRule(ElementTransitions *aOwner,
TimeStamp aRefreshTime)
: mElementTransitions(aOwner)
, mRefreshTime(aRefreshTime)
{}
void Disconnect() { mElementTransitions = nsnull; }
ElementTransitions *ElementData() { return mElementTransitions; }
TimeStamp RefreshTime() { return mRefreshTime; }
private:
ElementTransitions *mElementTransitions;
// The time stamp for which this style rule is valid.
TimeStamp mRefreshTime;
};
/**
* A CoverTransitionStyleRule sets any value for which we're starting a
* transition back to the pre-transition value for the period when we're
* resolving style on its descendants, so that we have the required
* behavior for initiating transitions on such descendants. For more
* detail, see comment below, above "new CoverTransitionStartStyleRule".
*/
class CoverTransitionStartStyleRule : public nsIStyleRule
{
public:
// nsISupportsImplementation
NS_DECL_ISUPPORTS
// nsIStyleRule implementation
NS_IMETHOD MapRuleInfoInto(nsRuleData* aRuleData);
#ifdef DEBUG
NS_IMETHOD List(FILE* out = stdout, PRInt32 aIndent = 0) const;
#endif
NS_HIDDEN_(void) CoverValue(nsCSSProperty aProperty,
nsStyleAnimation::Value &aStartValue)
{
CoveredValue v = { aProperty, aStartValue };
mCoveredValues.AppendElement(v);
}
struct CoveredValue {
nsCSSProperty mProperty;
nsStyleAnimation::Value mCoveredValue;
};
private:
nsTArray<CoveredValue> mCoveredValues;
};
struct ElementTransitions : public PRCList
{
ElementTransitions(nsIContent *aElement, nsIAtom *aElementProperty,
nsTransitionManager *aTransitionManager)
: mElement(aElement)
, mElementProperty(aElementProperty)
, mTransitionManager(aTransitionManager)
{
PR_INIT_CLIST(this);
}
~ElementTransitions()
{
DropStyleRule();
PR_REMOVE_LINK(this);
mTransitionManager->TransitionsRemoved();
}
void Destroy()
{
// This will call our destructor.
mElement->DeleteProperty(mElementProperty);
}
void DropStyleRule();
PRBool EnsureStyleRuleFor(TimeStamp aRefreshTime);
// Either zero or one for each CSS property:
nsTArray<ElementPropertyTransition> mPropertyTransitions;
// The style rule for the transitions (which contains the time stamp
// for which it is valid).
nsRefPtr<ElementTransitionsStyleRule> mStyleRule;
nsIContent *mElement;
// the atom we use in mElement's prop table (must be a static atom,
// i.e., in an atom list)
nsIAtom *mElementProperty;
nsTransitionManager *mTransitionManager;
};
static void
ElementTransitionsPropertyDtor(void *aObject,
nsIAtom *aPropertyName,
void *aPropertyValue,
void *aData)
{
ElementTransitions *et = static_cast<ElementTransitions*>(aPropertyValue);
delete et;
}
NS_IMPL_ISUPPORTS1(ElementTransitionsStyleRule, nsIStyleRule)
NS_IMETHODIMP
ElementTransitionsStyleRule::MapRuleInfoInto(nsRuleData* aRuleData)
{
nsStyleContext *contextParent = aRuleData->mStyleContext->GetParent();
if (contextParent && contextParent->HasPseudoElementData()) {
// Don't apply transitions to things inside of pseudo-elements.
// FIXME (Bug 522599): Add tests for this.
return NS_OK;
}
ElementTransitions *et = ElementData();
NS_ENSURE_TRUE(et, NS_OK); // FIXME (Bug 522597): Why can this be null?
for (PRUint32 i = 0, i_end = et->mPropertyTransitions.Length();
i < i_end; ++i)
{
ElementPropertyTransition &pt = et->mPropertyTransitions[i];
if (aRuleData->mSIDs & nsCachedStyleData::GetBitForSID(
nsCSSProps::kSIDTable[pt.mProperty]))
{
double timePortion =
(RefreshTime() - pt.mStartTime).ToSeconds() / pt.mDuration.ToSeconds();
if (timePortion < 0.0)
timePortion = 0.0; // use start value during transition-delay
if (timePortion > 1.0)
timePortion = 1.0; // we might be behind on flushing
double valuePortion =
pt.mTimingFunction.GetSplineValue(timePortion);
#ifdef DEBUG
PRBool ok =
#endif
nsStyleAnimation::Interpolate(pt.mProperty,
pt.mStartValue, pt.mEndValue,
valuePortion, pt.mCurrentValue);
NS_ABORT_IF_FALSE(ok, "could not interpolate values");
void *prop =
nsCSSExpandedDataBlock::RuleDataPropertyAt(aRuleData, pt.mProperty);
#ifdef DEBUG
ok =
#endif
nsStyleAnimation::UncomputeValue(pt.mProperty, aRuleData->mPresContext,
pt.mCurrentValue, prop);
NS_ABORT_IF_FALSE(ok, "could not store computed value");
}
}
return NS_OK;
}
#ifdef DEBUG
NS_IMETHODIMP
ElementTransitionsStyleRule::List(FILE* out, PRInt32 aIndent) const
{
// WRITE ME?
return NS_OK;
}
#endif
void
ElementTransitions::DropStyleRule()
{
if (mStyleRule) {
mStyleRule->Disconnect();
mStyleRule = nsnull;
}
}
PRBool
ElementTransitions::EnsureStyleRuleFor(TimeStamp aRefreshTime)
{
if (!mStyleRule || mStyleRule->RefreshTime() != aRefreshTime) {
DropStyleRule();
ElementTransitionsStyleRule *newRule =
new ElementTransitionsStyleRule(this, aRefreshTime);
if (!newRule) {
NS_WARNING("out of memory");
return PR_FALSE;
}
mStyleRule = newRule;
}
return PR_TRUE;
}
NS_IMPL_ISUPPORTS1(CoverTransitionStartStyleRule, nsIStyleRule)
NS_IMETHODIMP
CoverTransitionStartStyleRule::MapRuleInfoInto(nsRuleData* aRuleData)
{
for (PRUint32 i = 0, i_end = mCoveredValues.Length(); i < i_end; ++i) {
CoveredValue &cv = mCoveredValues[i];
if (aRuleData->mSIDs & nsCachedStyleData::GetBitForSID(
nsCSSProps::kSIDTable[cv.mProperty]))
{
void *prop =
nsCSSExpandedDataBlock::RuleDataPropertyAt(aRuleData, cv.mProperty);
#ifdef DEBUG
PRBool ok =
#endif
nsStyleAnimation::UncomputeValue(cv.mProperty, aRuleData->mPresContext,
cv.mCoveredValue, prop);
NS_ABORT_IF_FALSE(ok, "could not store computed value");
}
}
return NS_OK;
}
#ifdef DEBUG
NS_IMETHODIMP
CoverTransitionStartStyleRule::List(FILE* out, PRInt32 aIndent) const
{
// WRITE ME?
return NS_OK;
}
#endif
/*****************************************************************************
* nsTransitionManager *
*****************************************************************************/
nsTransitionManager::nsTransitionManager(nsPresContext *aPresContext)
: mPresContext(aPresContext)
{
PR_INIT_CLIST(&mElementTransitions);
}
nsTransitionManager::~nsTransitionManager()
{
// Content nodes might outlive the transition manager.
while (!PR_CLIST_IS_EMPTY(&mElementTransitions)) {
ElementTransitions *head = static_cast<ElementTransitions*>(
PR_LIST_HEAD(&mElementTransitions));
head->Destroy();
}
}
already_AddRefed<nsIStyleRule>
nsTransitionManager::StyleContextChanged(nsIContent *aElement,
nsStyleContext *aOldStyleContext,
nsStyleContext *aNewStyleContext)
{
NS_PRECONDITION(aOldStyleContext->GetPseudo() ==
aNewStyleContext->GetPseudo(),
"pseudo type mismatch");
// If we were called from ReParentStyleContext, this assertion would
// actually fire. If we need to be called from there, we can probably
// just remove it; the condition probably isn't critical, although
// it's worth thinking about some more.
NS_PRECONDITION(aOldStyleContext->HasPseudoElementData() ==
aNewStyleContext->HasPseudoElementData(),
"pseudo type mismatch");
// Return sooner (before the startedAny check below) for the most
// common case: no transitions specified.
const nsStyleDisplay *disp = aNewStyleContext->GetStyleDisplay();
if (disp->mTransitionPropertyCount == 1 &&
disp->mTransitions[0].GetDelay() == 0.0f &&
disp->mTransitions[0].GetDuration() == 0.0f) {
return nsnull;
}
if (aNewStyleContext->PresContext()->IsProcessingAnimationStyleChange()) {
return nsnull;
}
nsIAtom *pseudo = aNewStyleContext->GetPseudo();
if (pseudo && (pseudo != nsCSSPseudoElements::before &&
pseudo != nsCSSPseudoElements::after)) {
return nsnull;
}
if (aNewStyleContext->GetParent() &&
aNewStyleContext->GetParent()->HasPseudoElementData()) {
// Ignore transitions on things that inherit properties from
// pseudo-elements.
// FIXME (Bug 522599): Add tests for this.
return nsnull;
}
// Per http://lists.w3.org/Archives/Public/www-style/2009Aug/0109.html
// I'll consider only the transitions from the number of items in
// 'transition-property' on down, and later ones will override earlier
// ones (tracked using |whichStarted|).
PRBool startedAny = PR_FALSE;
nsCSSPropertySet whichStarted;
ElementTransitions *et = nsnull;
for (PRUint32 i = disp->mTransitionPropertyCount; i-- != 0; ) {
const nsTransition& t = disp->mTransitions[i];
// Check delay and duration first, since they default to zero, and
// when they're both zero, we can ignore the transition.
if (t.GetDelay() != 0.0f || t.GetDuration() != 0.0f) {
et = GetElementTransitions(aElement,
aNewStyleContext->GetPseudo(),
PR_FALSE);
// We might have something to transition. See if any of the
// properties in question changed and are animatable.
nsCSSProperty property = t.GetProperty();
if (property == eCSSPropertyExtra_no_properties ||
property == eCSSProperty_UNKNOWN) {
// Nothing to do, but need to exclude this from cases below.
} else if (property == eCSSPropertyExtra_all_properties) {
for (nsCSSProperty p = nsCSSProperty(0);
p < eCSSProperty_COUNT_no_shorthands;
p = nsCSSProperty(p + 1)) {
ConsiderStartingTransition(p, t, aElement, et,
aOldStyleContext, aNewStyleContext,
&startedAny, &whichStarted);
}
} else if (nsCSSProps::IsShorthand(property)) {
CSSPROPS_FOR_SHORTHAND_SUBPROPERTIES(subprop, property) {
ConsiderStartingTransition(*subprop, t, aElement, et,
aOldStyleContext, aNewStyleContext,
&startedAny, &whichStarted);
}
} else {
ConsiderStartingTransition(property, t, aElement, et,
aOldStyleContext, aNewStyleContext,
&startedAny, &whichStarted);
}
}
}
if (!startedAny) {
return nsnull;
}
NS_ABORT_IF_FALSE(et, "must have element transitions if we started "
"any transitions");
// In the CSS working group discussion (2009 Jul 15 telecon,
// http://www.w3.org/mid/4A5E1470.4030904@inkedblade.net ) of
// http://lists.w3.org/Archives/Public/www-style/2009Jun/0121.html ,
// the working group decided that a transition property on an
// element should not cause any transitions if the property change
// is itself inheriting a value that is transitioning on an
// ancestor. So, to get the correct behavior, we continue the
// restyle that caused this transition using a "covering" rule that
// covers up any changes on which we started transitions, so that
// descendants don't start their own transitions. (In the case of
// negative transition delay, this covering rule produces different
// results than applying the transition rule immediately would).
// Our caller is responsible for restyling again using this covering
// rule.
nsRefPtr<CoverTransitionStartStyleRule> coverRule =
new CoverTransitionStartStyleRule;
if (!coverRule) {
NS_WARNING("out of memory");
return nsnull;
}
nsTArray<ElementPropertyTransition> &pts = et->mPropertyTransitions;
for (PRUint32 i = 0, i_end = pts.Length(); i < i_end; ++i) {
ElementPropertyTransition &pt = pts[i];
if (whichStarted.HasProperty(pt.mProperty)) {
coverRule->CoverValue(pt.mProperty, pt.mStartValue);
}
}
return already_AddRefed<nsIStyleRule>(
static_cast<nsIStyleRule*>(coverRule.forget().get()));
}
void
nsTransitionManager::ConsiderStartingTransition(nsCSSProperty aProperty,
const nsTransition& aTransition,
nsIContent *aElement,
ElementTransitions *&aElementTransitions,
nsStyleContext *aOldStyleContext,
nsStyleContext *aNewStyleContext,
PRBool *aStartedAny,
nsCSSPropertySet *aWhichStarted)
{
// IsShorthand itself will assert if aProperty is not a property.
NS_ABORT_IF_FALSE(!nsCSSProps::IsShorthand(aProperty),
"property out of range");
if (aWhichStarted->HasProperty(aProperty)) {
// A later item in transition-property already started a
// transition for this property, so we ignore this one.
// See comment above and
// http://lists.w3.org/Archives/Public/www-style/2009Aug/0109.html .
return;
}
if (nsCSSProps::kAnimTypeTable[aProperty] == eStyleAnimType_None) {
return;
}
ElementPropertyTransition pt;
nsStyleAnimation::Value dummyValue;
// FIXME (Bug 522595): This call on the old style context gets
// incorrect style data since we don't quite enforce style rule
// immutability: we didn't need to worry about callers calling
// GetStyleData rather than PeekStyleData after a style rule becomes
// "old" before transitions existed.
PRBool shouldAnimate =
nsStyleAnimation::ExtractComputedValue(aProperty, aOldStyleContext,
pt.mStartValue) &&
nsStyleAnimation::ExtractComputedValue(aProperty, aNewStyleContext,
pt.mEndValue) &&
pt.mStartValue != pt.mEndValue &&
// Check that we can interpolate between these values
// (If this is ever a performance problem, we could add a
// CanInterpolate method, but it seems fine for now.)
nsStyleAnimation::Interpolate(aProperty, pt.mStartValue, pt.mEndValue,
0.5, dummyValue);
PRUint32 currentIndex = nsTArray<ElementPropertyTransition>::NoIndex;
if (aElementTransitions) {
nsTArray<ElementPropertyTransition> &pts =
aElementTransitions->mPropertyTransitions;
for (PRUint32 i = 0, i_end = pts.Length(); i < i_end; ++i) {
if (pts[i].mProperty == aProperty) {
currentIndex = i;
break;
}
}
}
nsPresContext *presContext = aNewStyleContext->PresContext();
if (!shouldAnimate) {
if (currentIndex != nsTArray<ElementPropertyTransition>::NoIndex) {
// We're in the middle of a transition, but just got a
// non-transition style change changing to exactly the
// current in-progress value. (This is quite easy to cause
// using 'transition-delay'.)
nsTArray<ElementPropertyTransition> &pts =
aElementTransitions->mPropertyTransitions;
pts.RemoveElementAt(currentIndex);
if (pts.IsEmpty()) {
aElementTransitions->Destroy();
// |aElementTransitions| is now a dangling pointer!
aElementTransitions = nsnull;
}
presContext->PresShell()->RestyleForAnimation(aElement);
}
return;
}
// When we interrupt a running transition, we want to reduce the
// duration of the new transition *if* the new transition would have
// been longer had it started from the endpoint of the currently
// running transition.
double durationFraction = 1.0;
// We need to check two things if we have a currently running
// transition for this property: see durationFraction comment above
// and the endpoint check below.
if (currentIndex != nsTArray<ElementPropertyTransition>::NoIndex) {
const nsStyleAnimation::Value &endVal =
aElementTransitions->mPropertyTransitions[currentIndex].mEndValue;
if (endVal == pt.mEndValue) {
// If we got a style change that changed the value to the endpoint
// of the currently running transition, we don't want to interrupt
// its timing function.
// But don't forget to restyle with animation so we show the
// current transition.
presContext->PresShell()->RestyleForAnimation(aElement);
return;
}
double fullDistance, remainingDistance;
#ifdef DEBUG
PRBool ok =
#endif
nsStyleAnimation::ComputeDistance(aProperty, pt.mStartValue,
pt.mEndValue, fullDistance);
NS_ABORT_IF_FALSE(ok, "could not compute distance");
NS_ABORT_IF_FALSE(fullDistance >= 0.0, "distance must be positive");
if (nsStyleAnimation::ComputeDistance(aProperty, endVal, pt.mEndValue,
remainingDistance)) {
NS_ABORT_IF_FALSE(remainingDistance >= 0.0, "distance must be positive");
durationFraction = fullDistance / remainingDistance;
if (durationFraction > 1.0) {
durationFraction = 1.0;
}
}
}
nsRefreshDriver *rd = presContext->RefreshDriver();
pt.mProperty = aProperty;
float delay = aTransition.GetDelay();
float duration = aTransition.GetDuration();
if (durationFraction != 1.0) {
// Negative delays are essentially part of the transition
// function, so reduce them along with the duration, but don't
// reduce positive delays. (See comment above about
// durationFraction.)
if (delay < 0.0f)
delay *= durationFraction;
duration *= durationFraction;
}
pt.mStartTime = rd->MostRecentRefresh() +
TimeDuration::FromMilliseconds(delay);
pt.mDuration = TimeDuration::FromMilliseconds(duration);
const nsTimingFunction &tf = aTransition.GetTimingFunction();
pt.mTimingFunction.Init(tf.mX1, tf.mY1, tf.mX2, tf.mY2);
if (!aElementTransitions) {
aElementTransitions =
GetElementTransitions(aElement, aNewStyleContext->GetPseudo(),
PR_TRUE);
if (!aElementTransitions) {
NS_WARNING("allocating ElementTransitions failed");
return;
}
}
nsTArray<ElementPropertyTransition> &pts =
aElementTransitions->mPropertyTransitions;
#ifdef DEBUG
for (PRUint32 i = 0, i_end = pts.Length(); i < i_end; ++i) {
NS_ABORT_IF_FALSE(i == currentIndex ||
pts[i].mProperty != aProperty,
"duplicate transitions for property");
}
#endif
if (currentIndex != nsTArray<ElementPropertyTransition>::NoIndex) {
pts[currentIndex] = pt;
} else {
if (!pts.AppendElement(pt)) {
NS_WARNING("out of memory");
return;
}
}
presContext->PresShell()->RestyleForAnimation(aElement);
*aStartedAny = PR_TRUE;
aWhichStarted->AddProperty(aProperty);
}
ElementTransitions*
nsTransitionManager::GetElementTransitions(nsIContent *aElement,
nsIAtom *aPseudo,
PRBool aCreateIfNeeded)
{
nsIAtom *propName;
if (aPseudo == nsCSSPseudoElements::before) {
propName = nsGkAtoms::transitionsOfBeforeProperty;
} else if (aPseudo == nsCSSPseudoElements::after) {
propName = nsGkAtoms::transitionsOfAfterProperty;
} else {
NS_ASSERTION(!aPseudo || !aCreateIfNeeded,
"should never try to create transitions for pseudo "
"other than :before or :after");
propName = nsGkAtoms::transitionsProperty;
}
ElementTransitions *et = static_cast<ElementTransitions*>(
aElement->GetProperty(propName));
if (!et && aCreateIfNeeded) {
// FIXME: Consider arena-allocating?
et = new ElementTransitions(aElement, propName, this);
if (!et) {
NS_WARNING("out of memory");
return nsnull;
}
nsresult rv = aElement->SetProperty(propName, et,
ElementTransitionsPropertyDtor, nsnull);
if (NS_FAILED(rv)) {
NS_WARNING("SetProperty failed");
delete et;
return nsnull;
}
AddElementTransitions(et);
}
return et;
}
void
nsTransitionManager::AddElementTransitions(ElementTransitions* aElementTransitions)
{
if (PR_CLIST_IS_EMPTY(&mElementTransitions)) {
// We need to observe the refresh driver.
nsRefreshDriver *rd = mPresContext->RefreshDriver();
rd->AddRefreshObserver(this, Flush_Style);
}
PR_INSERT_BEFORE(aElementTransitions, &mElementTransitions);
}
/*
* nsISupports implementation
*/
NS_IMPL_ADDREF_USING_AGGREGATOR(nsTransitionManager, mPresContext)
NS_IMPL_RELEASE_USING_AGGREGATOR(nsTransitionManager, mPresContext)
NS_IMPL_QUERY_INTERFACE1(nsTransitionManager, nsIStyleRuleProcessor)
/*
* nsIStyleRuleProcessor implementation
*/
nsresult
nsTransitionManager::WalkTransitionRule(RuleProcessorData* aData,
nsIAtom *aPseudo)
{
if (!aData->mPresContext->IsProcessingAnimationStyleChange()) {
// If we're processing a normal style change rather than one from
// animation, don't add the transition rule. This allows us to
// compute the new style value rather than having the transition
// override it, so that we can start transitioning differently.
// In most cases, we need to immediately restyle with animation
// after doing this. However, ConsiderStartingTransition takes care
// of that for us.
return NS_OK;
}
ElementTransitions *et =
GetElementTransitions(aData->mContent, aPseudo, PR_FALSE);
if (!et) {
return NS_OK;
}
if (!et->EnsureStyleRuleFor(
aData->mPresContext->RefreshDriver()->MostRecentRefresh())) {
return NS_ERROR_OUT_OF_MEMORY;
}
aData->mRuleWalker->Forward(et->mStyleRule);
return NS_OK;
}
NS_IMETHODIMP
nsTransitionManager::RulesMatching(ElementRuleProcessorData* aData)
{
NS_ABORT_IF_FALSE(aData->mPresContext == mPresContext,
"pres context mismatch");
return WalkTransitionRule(aData, nsnull);
}
NS_IMETHODIMP
nsTransitionManager::RulesMatching(PseudoRuleProcessorData* aData)
{
NS_ABORT_IF_FALSE(aData->mPresContext == mPresContext,
"pres context mismatch");
// Note: If we're the only thing keeping a pseudo-element frame alive
// (per ProbePseudoStyleContext), we still want to keep it alive, so
// this is ok.
return WalkTransitionRule(aData, aData->mPseudoTag);
}
NS_IMETHODIMP
nsTransitionManager::HasStateDependentStyle(StateRuleProcessorData* aData,
nsReStyleHint* aResult)
{
*aResult = nsReStyleHint(0);
return NS_OK;
}
nsReStyleHint
nsTransitionManager::HasAttributeDependentStyle(AttributeRuleProcessorData* aData)
{
return nsReStyleHint(0);
}
NS_IMETHODIMP
nsTransitionManager::MediumFeaturesChanged(nsPresContext* aPresContext,
PRBool* aRulesChanged)
{
*aRulesChanged = PR_FALSE;
return NS_OK;
}
/* virtual */ void
nsTransitionManager::WillRefresh(mozilla::TimeStamp aTime)
{
// Trim transitions that have completed, and post restyle events for
// frames that are still transitioning.
{
PRCList *next = PR_LIST_HEAD(&mElementTransitions);
while (next != &mElementTransitions) {
ElementTransitions *et = static_cast<ElementTransitions*>(next);
next = PR_NEXT_LINK(next);
NS_ABORT_IF_FALSE(et->mElement->GetCurrentDoc() ==
mPresContext->Document(),
"nsGenericElement::UnbindFromTree should have "
"destroyed the element transitions object");
PRUint32 i = et->mPropertyTransitions.Length();
NS_ABORT_IF_FALSE(i != 0, "empty transitions list?");
do {
--i;
ElementPropertyTransition &pt = et->mPropertyTransitions[i];
if (pt.mStartTime + pt.mDuration <= aTime) {
// This transition has completed.
et->mPropertyTransitions.RemoveElementAt(i);
}
} while (i != 0);
// We need to restyle even if the transition rule no longer
// applies (in which case we just made it not apply).
mPresContext->PresShell()->RestyleForAnimation(et->mElement);
if (et->mPropertyTransitions.IsEmpty()) {
et->Destroy();
// |et| is now a dangling pointer!
et = nsnull;
}
}
}
// We might have removed transitions above.
TransitionsRemoved();
}
void
nsTransitionManager::TransitionsRemoved()
{
// If we have no transitions left, remove ourselves from the refresh
// driver.
if (PR_CLIST_IS_EMPTY(&mElementTransitions)) {
mPresContext->RefreshDriver()->RemoveRefreshObserver(this, Flush_Style);
}
}