gecko-dev/dom/smil/nsSMILTimeContainer.cpp

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C++

/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=8 sts=2 et sw=2 tw=80: */
/* 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/. */
#include "nsSMILTimeContainer.h"
#include "nsSMILTimeValue.h"
#include "nsSMILTimedElement.h"
#include <algorithm>
#include "mozilla/AutoRestore.h"
using namespace mozilla;
nsSMILTimeContainer::nsSMILTimeContainer()
:
mParent(nullptr),
mCurrentTime(0L),
mParentOffset(0L),
mPauseStart(0L),
mNeedsPauseSample(false),
mNeedsRewind(false),
mIsSeeking(false),
#ifdef DEBUG
mHoldingEntries(false),
#endif
mPauseState(PAUSE_BEGIN)
{
}
nsSMILTimeContainer::~nsSMILTimeContainer()
{
if (mParent) {
mParent->RemoveChild(*this);
}
}
nsSMILTimeValue
nsSMILTimeContainer::ContainerToParentTime(nsSMILTime aContainerTime) const
{
// If we're paused, then future times are indefinite
if (IsPaused() && aContainerTime > mCurrentTime)
return nsSMILTimeValue::Indefinite();
return nsSMILTimeValue(aContainerTime + mParentOffset);
}
nsSMILTimeValue
nsSMILTimeContainer::ParentToContainerTime(nsSMILTime aParentTime) const
{
// If we're paused, then any time after when we paused is indefinite
if (IsPaused() && aParentTime > mPauseStart)
return nsSMILTimeValue::Indefinite();
return nsSMILTimeValue(aParentTime - mParentOffset);
}
void
nsSMILTimeContainer::Begin()
{
Resume(PAUSE_BEGIN);
if (mPauseState) {
mNeedsPauseSample = true;
}
// This is a little bit complicated here. Ideally we'd just like to call
// Sample() and force an initial sample but this turns out to be a bad idea
// because this may mean that NeedsSample() no longer reports true and so when
// we come to the first real sample our parent will skip us over altogether.
// So we force the time to be updated and adopt the policy to never call
// Sample() ourselves but to always leave that to our parent or client.
UpdateCurrentTime();
}
void
nsSMILTimeContainer::Pause(uint32_t aType)
{
bool didStartPause = false;
if (!mPauseState && aType) {
mPauseStart = GetParentTime();
mNeedsPauseSample = true;
didStartPause = true;
}
mPauseState |= aType;
if (didStartPause) {
NotifyTimeChange();
}
}
void
nsSMILTimeContainer::Resume(uint32_t aType)
{
if (!mPauseState)
return;
mPauseState &= ~aType;
if (!mPauseState) {
nsSMILTime extraOffset = GetParentTime() - mPauseStart;
mParentOffset += extraOffset;
NotifyTimeChange();
}
}
nsSMILTime
nsSMILTimeContainer::GetCurrentTime() const
{
// The following behaviour is consistent with:
// http://www.w3.org/2003/01/REC-SVG11-20030114-errata
// #getCurrentTime_setCurrentTime_undefined_before_document_timeline_begin
// which says that if GetCurrentTime is called before the document timeline
// has begun we should just return 0.
if (IsPausedByType(PAUSE_BEGIN))
return 0L;
return mCurrentTime;
}
void
nsSMILTimeContainer::SetCurrentTime(nsSMILTime aSeekTo)
{
// SVG 1.1 doesn't specify what to do for negative times so we adopt SVGT1.2's
// behaviour of clamping negative times to 0.
aSeekTo = std::max<nsSMILTime>(0, aSeekTo);
// The following behaviour is consistent with:
// http://www.w3.org/2003/01/REC-SVG11-20030114-errata
// #getCurrentTime_setCurrentTime_undefined_before_document_timeline_begin
// which says that if SetCurrentTime is called before the document timeline
// has begun we should still adjust the offset.
nsSMILTime parentTime = GetParentTime();
mParentOffset = parentTime - aSeekTo;
mIsSeeking = true;
if (IsPaused()) {
mNeedsPauseSample = true;
mPauseStart = parentTime;
}
if (aSeekTo < mCurrentTime) {
// Backwards seek
mNeedsRewind = true;
ClearMilestones();
}
// Force an update to the current time in case we get a call to GetCurrentTime
// before another call to Sample().
UpdateCurrentTime();
NotifyTimeChange();
}
nsSMILTime
nsSMILTimeContainer::GetParentTime() const
{
if (mParent)
return mParent->GetCurrentTime();
return 0L;
}
void
nsSMILTimeContainer::SyncPauseTime()
{
if (IsPaused()) {
nsSMILTime parentTime = GetParentTime();
nsSMILTime extraOffset = parentTime - mPauseStart;
mParentOffset += extraOffset;
mPauseStart = parentTime;
}
}
void
nsSMILTimeContainer::Sample()
{
if (!NeedsSample())
return;
UpdateCurrentTime();
DoSample();
mNeedsPauseSample = false;
}
nsresult
nsSMILTimeContainer::SetParent(nsSMILTimeContainer* aParent)
{
if (mParent) {
mParent->RemoveChild(*this);
// When we're not attached to a parent time container, GetParentTime() will
// return 0. We need to adjust our pause state information to be relative to
// this new time base.
// Note that since "current time = parent time - parent offset" setting the
// parent offset and pause start as follows preserves our current time even
// while parent time = 0.
mParentOffset = -mCurrentTime;
mPauseStart = 0L;
}
mParent = aParent;
nsresult rv = NS_OK;
if (mParent) {
rv = mParent->AddChild(*this);
}
return rv;
}
bool
nsSMILTimeContainer::AddMilestone(const nsSMILMilestone& aMilestone,
mozilla::dom::SVGAnimationElement& aElement)
{
// We record the milestone time and store it along with the element but this
// time may change (e.g. if attributes are changed on the timed element in
// between samples). If this happens, then we may do an unecessary sample
// but that's pretty cheap.
MOZ_ASSERT(!mHoldingEntries);
return mMilestoneEntries.Push(MilestoneEntry(aMilestone, aElement));
}
void
nsSMILTimeContainer::ClearMilestones()
{
MOZ_ASSERT(!mHoldingEntries);
mMilestoneEntries.Clear();
}
bool
nsSMILTimeContainer::GetNextMilestoneInParentTime(
nsSMILMilestone& aNextMilestone) const
{
if (mMilestoneEntries.IsEmpty())
return false;
nsSMILTimeValue parentTime =
ContainerToParentTime(mMilestoneEntries.Top().mMilestone.mTime);
if (!parentTime.IsDefinite())
return false;
aNextMilestone = nsSMILMilestone(parentTime.GetMillis(),
mMilestoneEntries.Top().mMilestone.mIsEnd);
return true;
}
bool
nsSMILTimeContainer::PopMilestoneElementsAtMilestone(
const nsSMILMilestone& aMilestone,
AnimElemArray& aMatchedElements)
{
if (mMilestoneEntries.IsEmpty())
return false;
nsSMILTimeValue containerTime = ParentToContainerTime(aMilestone.mTime);
if (!containerTime.IsDefinite())
return false;
nsSMILMilestone containerMilestone(containerTime.GetMillis(),
aMilestone.mIsEnd);
MOZ_ASSERT(mMilestoneEntries.Top().mMilestone >= containerMilestone,
"Trying to pop off earliest times but we have earlier ones that "
"were overlooked");
MOZ_ASSERT(!mHoldingEntries);
bool gotOne = false;
while (!mMilestoneEntries.IsEmpty() &&
mMilestoneEntries.Top().mMilestone == containerMilestone)
{
aMatchedElements.AppendElement(mMilestoneEntries.Pop().mTimebase);
gotOne = true;
}
return gotOne;
}
void
nsSMILTimeContainer::Traverse(nsCycleCollectionTraversalCallback* aCallback)
{
#ifdef DEBUG
AutoRestore<bool> saveHolding(mHoldingEntries);
mHoldingEntries = true;
#endif
const MilestoneEntry* p = mMilestoneEntries.Elements();
while (p < mMilestoneEntries.Elements() + mMilestoneEntries.Length()) {
NS_CYCLE_COLLECTION_NOTE_EDGE_NAME(*aCallback, "mTimebase");
aCallback->NoteXPCOMChild(static_cast<nsIContent*>(p->mTimebase.get()));
++p;
}
}
void
nsSMILTimeContainer::Unlink()
{
MOZ_ASSERT(!mHoldingEntries);
mMilestoneEntries.Clear();
}
void
nsSMILTimeContainer::UpdateCurrentTime()
{
nsSMILTime now = IsPaused() ? mPauseStart : GetParentTime();
mCurrentTime = now - mParentOffset;
MOZ_ASSERT(mCurrentTime >= 0, "Container has negative time");
}
void
nsSMILTimeContainer::NotifyTimeChange()
{
// Called when the container time is changed with respect to the document
// time. When this happens time dependencies in other time containers need to
// re-resolve their times because begin and end times are stored in container
// time.
//
// To get the list of timed elements with dependencies we simply re-use the
// milestone elements. This is because any timed element with dependents and
// with significant transitions yet to fire should have their next milestone
// registered. Other timed elements don't matter.
// Copy the timed elements to a separate array before calling
// HandleContainerTimeChange on each of them in case doing so mutates
// mMilestoneEntries.
nsTArray<RefPtr<mozilla::dom::SVGAnimationElement>> elems;
{
#ifdef DEBUG
AutoRestore<bool> saveHolding(mHoldingEntries);
mHoldingEntries = true;
#endif
for (const MilestoneEntry* p = mMilestoneEntries.Elements();
p < mMilestoneEntries.Elements() + mMilestoneEntries.Length();
++p) {
elems.AppendElement(p->mTimebase.get());
}
}
for (auto& elem : elems) {
elem->TimedElement().HandleContainerTimeChange();
}
}