michael@0: /* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
michael@0: /* This Source Code Form is subject to the terms of the Mozilla Public
michael@0:  * License, v. 2.0. If a copy of the MPL was not distributed with this
michael@0:  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
michael@0: 
michael@0: #include "nsSMILTimeContainer.h"
michael@0: #include "nsSMILTimeValue.h"
michael@0: #include "nsSMILTimedElement.h"
michael@0: #include <algorithm>
michael@0: 
michael@0: nsSMILTimeContainer::nsSMILTimeContainer()
michael@0: :
michael@0:   mParent(nullptr),
michael@0:   mCurrentTime(0L),
michael@0:   mParentOffset(0L),
michael@0:   mPauseStart(0L),
michael@0:   mNeedsPauseSample(false),
michael@0:   mNeedsRewind(false),
michael@0:   mIsSeeking(false),
michael@0:   mPauseState(PAUSE_BEGIN)
michael@0: {
michael@0: }
michael@0: 
michael@0: nsSMILTimeContainer::~nsSMILTimeContainer()
michael@0: {
michael@0:   if (mParent) {
michael@0:     mParent->RemoveChild(*this);
michael@0:   }
michael@0: }
michael@0: 
michael@0: nsSMILTimeValue
michael@0: nsSMILTimeContainer::ContainerToParentTime(nsSMILTime aContainerTime) const
michael@0: {
michael@0:   // If we're paused, then future times are indefinite
michael@0:   if (IsPaused() && aContainerTime > mCurrentTime)
michael@0:     return nsSMILTimeValue::Indefinite();
michael@0: 
michael@0:   return nsSMILTimeValue(aContainerTime + mParentOffset);
michael@0: }
michael@0: 
michael@0: nsSMILTimeValue
michael@0: nsSMILTimeContainer::ParentToContainerTime(nsSMILTime aParentTime) const
michael@0: {
michael@0:   // If we're paused, then any time after when we paused is indefinite
michael@0:   if (IsPaused() && aParentTime > mPauseStart)
michael@0:     return nsSMILTimeValue::Indefinite();
michael@0: 
michael@0:   return nsSMILTimeValue(aParentTime - mParentOffset);
michael@0: }
michael@0: 
michael@0: void
michael@0: nsSMILTimeContainer::Begin()
michael@0: {
michael@0:   Resume(PAUSE_BEGIN);
michael@0:   if (mPauseState) {
michael@0:     mNeedsPauseSample = true;
michael@0:   }
michael@0: 
michael@0:   // This is a little bit complicated here. Ideally we'd just like to call
michael@0:   // Sample() and force an initial sample but this turns out to be a bad idea
michael@0:   // because this may mean that NeedsSample() no longer reports true and so when
michael@0:   // we come to the first real sample our parent will skip us over altogether.
michael@0:   // So we force the time to be updated and adopt the policy to never call
michael@0:   // Sample() ourselves but to always leave that to our parent or client.
michael@0: 
michael@0:   UpdateCurrentTime();
michael@0: }
michael@0: 
michael@0: void
michael@0: nsSMILTimeContainer::Pause(uint32_t aType)
michael@0: {
michael@0:   bool didStartPause = false;
michael@0: 
michael@0:   if (!mPauseState && aType) {
michael@0:     mPauseStart = GetParentTime();
michael@0:     mNeedsPauseSample = true;
michael@0:     didStartPause = true;
michael@0:   }
michael@0: 
michael@0:   mPauseState |= aType;
michael@0: 
michael@0:   if (didStartPause) {
michael@0:     NotifyTimeChange();
michael@0:   }
michael@0: }
michael@0: 
michael@0: void
michael@0: nsSMILTimeContainer::Resume(uint32_t aType)
michael@0: {
michael@0:   if (!mPauseState)
michael@0:     return;
michael@0: 
michael@0:   mPauseState &= ~aType;
michael@0: 
michael@0:   if (!mPauseState) {
michael@0:     nsSMILTime extraOffset = GetParentTime() - mPauseStart;
michael@0:     mParentOffset += extraOffset;
michael@0:     NotifyTimeChange();
michael@0:   }
michael@0: }
michael@0: 
michael@0: nsSMILTime
michael@0: nsSMILTimeContainer::GetCurrentTime() const
michael@0: {
michael@0:   // The following behaviour is consistent with:
michael@0:   // http://www.w3.org/2003/01/REC-SVG11-20030114-errata
michael@0:   //  #getCurrentTime_setCurrentTime_undefined_before_document_timeline_begin
michael@0:   // which says that if GetCurrentTime is called before the document timeline
michael@0:   // has begun we should just return 0.
michael@0:   if (IsPausedByType(PAUSE_BEGIN))
michael@0:     return 0L;
michael@0: 
michael@0:   return mCurrentTime;
michael@0: }
michael@0: 
michael@0: void
michael@0: nsSMILTimeContainer::SetCurrentTime(nsSMILTime aSeekTo)
michael@0: {
michael@0:   // SVG 1.1 doesn't specify what to do for negative times so we adopt SVGT1.2's
michael@0:   // behaviour of clamping negative times to 0.
michael@0:   aSeekTo = std::max<nsSMILTime>(0, aSeekTo);
michael@0: 
michael@0:   // The following behaviour is consistent with:
michael@0:   // http://www.w3.org/2003/01/REC-SVG11-20030114-errata
michael@0:   //  #getCurrentTime_setCurrentTime_undefined_before_document_timeline_begin
michael@0:   // which says that if SetCurrentTime is called before the document timeline
michael@0:   // has begun we should still adjust the offset.
michael@0:   nsSMILTime parentTime = GetParentTime();
michael@0:   mParentOffset = parentTime - aSeekTo;
michael@0:   mIsSeeking = true;
michael@0: 
michael@0:   if (IsPaused()) {
michael@0:     mNeedsPauseSample = true;
michael@0:     mPauseStart = parentTime;
michael@0:   }
michael@0: 
michael@0:   if (aSeekTo < mCurrentTime) {
michael@0:     // Backwards seek
michael@0:     mNeedsRewind = true;
michael@0:     ClearMilestones();
michael@0:   }
michael@0: 
michael@0:   // Force an update to the current time in case we get a call to GetCurrentTime
michael@0:   // before another call to Sample().
michael@0:   UpdateCurrentTime();
michael@0: 
michael@0:   NotifyTimeChange();
michael@0: }
michael@0: 
michael@0: nsSMILTime
michael@0: nsSMILTimeContainer::GetParentTime() const
michael@0: {
michael@0:   if (mParent)
michael@0:     return mParent->GetCurrentTime();
michael@0: 
michael@0:   return 0L;
michael@0: }
michael@0: 
michael@0: void
michael@0: nsSMILTimeContainer::SyncPauseTime()
michael@0: {
michael@0:   if (IsPaused()) {
michael@0:     nsSMILTime parentTime = GetParentTime();
michael@0:     nsSMILTime extraOffset = parentTime - mPauseStart;
michael@0:     mParentOffset += extraOffset;
michael@0:     mPauseStart = parentTime;
michael@0:   }
michael@0: }
michael@0: 
michael@0: void
michael@0: nsSMILTimeContainer::Sample()
michael@0: {
michael@0:   if (!NeedsSample())
michael@0:     return;
michael@0: 
michael@0:   UpdateCurrentTime();
michael@0:   DoSample();
michael@0: 
michael@0:   mNeedsPauseSample = false;
michael@0: }
michael@0: 
michael@0: nsresult
michael@0: nsSMILTimeContainer::SetParent(nsSMILTimeContainer* aParent)
michael@0: {
michael@0:   if (mParent) {
michael@0:     mParent->RemoveChild(*this);
michael@0:     // When we're not attached to a parent time container, GetParentTime() will
michael@0:     // return 0. We need to adjust our pause state information to be relative to
michael@0:     // this new time base.
michael@0:     // Note that since "current time = parent time - parent offset" setting the
michael@0:     // parent offset and pause start as follows preserves our current time even
michael@0:     // while parent time = 0.
michael@0:     mParentOffset = -mCurrentTime;
michael@0:     mPauseStart = 0L;
michael@0:   }
michael@0: 
michael@0:   mParent = aParent;
michael@0: 
michael@0:   nsresult rv = NS_OK;
michael@0:   if (mParent) {
michael@0:     rv = mParent->AddChild(*this);
michael@0:   }
michael@0: 
michael@0:   return rv;
michael@0: }
michael@0: 
michael@0: bool
michael@0: nsSMILTimeContainer::AddMilestone(const nsSMILMilestone& aMilestone,
michael@0:                                   mozilla::dom::SVGAnimationElement& aElement)
michael@0: {
michael@0:   // We record the milestone time and store it along with the element but this
michael@0:   // time may change (e.g. if attributes are changed on the timed element in
michael@0:   // between samples). If this happens, then we may do an unecessary sample
michael@0:   // but that's pretty cheap.
michael@0:   return mMilestoneEntries.Push(MilestoneEntry(aMilestone, aElement));
michael@0: }
michael@0: 
michael@0: void
michael@0: nsSMILTimeContainer::ClearMilestones()
michael@0: {
michael@0:   mMilestoneEntries.Clear();
michael@0: }
michael@0: 
michael@0: bool
michael@0: nsSMILTimeContainer::GetNextMilestoneInParentTime(
michael@0:     nsSMILMilestone& aNextMilestone) const
michael@0: {
michael@0:   if (mMilestoneEntries.IsEmpty())
michael@0:     return false;
michael@0: 
michael@0:   nsSMILTimeValue parentTime =
michael@0:     ContainerToParentTime(mMilestoneEntries.Top().mMilestone.mTime);
michael@0:   if (!parentTime.IsDefinite())
michael@0:     return false;
michael@0: 
michael@0:   aNextMilestone = nsSMILMilestone(parentTime.GetMillis(),
michael@0:                                    mMilestoneEntries.Top().mMilestone.mIsEnd);
michael@0: 
michael@0:   return true;
michael@0: }
michael@0: 
michael@0: bool
michael@0: nsSMILTimeContainer::PopMilestoneElementsAtMilestone(
michael@0:       const nsSMILMilestone& aMilestone,
michael@0:       AnimElemArray& aMatchedElements)
michael@0: {
michael@0:   if (mMilestoneEntries.IsEmpty())
michael@0:     return false;
michael@0: 
michael@0:   nsSMILTimeValue containerTime = ParentToContainerTime(aMilestone.mTime);
michael@0:   if (!containerTime.IsDefinite())
michael@0:     return false;
michael@0: 
michael@0:   nsSMILMilestone containerMilestone(containerTime.GetMillis(),
michael@0:                                      aMilestone.mIsEnd);
michael@0: 
michael@0:   NS_ABORT_IF_FALSE(mMilestoneEntries.Top().mMilestone >= containerMilestone,
michael@0:       "Trying to pop off earliest times but we have earlier ones that were "
michael@0:       "overlooked");
michael@0: 
michael@0:   bool gotOne = false;
michael@0:   while (!mMilestoneEntries.IsEmpty() &&
michael@0:       mMilestoneEntries.Top().mMilestone == containerMilestone)
michael@0:   {
michael@0:     aMatchedElements.AppendElement(mMilestoneEntries.Pop().mTimebase);
michael@0:     gotOne = true;
michael@0:   }
michael@0: 
michael@0:   return gotOne;
michael@0: }
michael@0: 
michael@0: void
michael@0: nsSMILTimeContainer::Traverse(nsCycleCollectionTraversalCallback* aCallback)
michael@0: {
michael@0:   const MilestoneEntry* p = mMilestoneEntries.Elements();
michael@0:   while (p < mMilestoneEntries.Elements() + mMilestoneEntries.Length()) {
michael@0:     NS_CYCLE_COLLECTION_NOTE_EDGE_NAME(*aCallback, "mTimebase");
michael@0:     aCallback->NoteXPCOMChild(static_cast<nsIContent*>(p->mTimebase.get()));
michael@0:     ++p;
michael@0:   }
michael@0: }
michael@0: 
michael@0: void
michael@0: nsSMILTimeContainer::Unlink()
michael@0: {
michael@0:   mMilestoneEntries.Clear();
michael@0: }
michael@0: 
michael@0: void
michael@0: nsSMILTimeContainer::UpdateCurrentTime()
michael@0: {
michael@0:   nsSMILTime now = IsPaused() ? mPauseStart : GetParentTime();
michael@0:   mCurrentTime = now - mParentOffset;
michael@0:   NS_ABORT_IF_FALSE(mCurrentTime >= 0, "Container has negative time");
michael@0: }
michael@0: 
michael@0: void
michael@0: nsSMILTimeContainer::NotifyTimeChange()
michael@0: {
michael@0:   // Called when the container time is changed with respect to the document
michael@0:   // time. When this happens time dependencies in other time containers need to
michael@0:   // re-resolve their times because begin and end times are stored in container
michael@0:   // time.
michael@0:   //
michael@0:   // To get the list of timed elements with dependencies we simply re-use the
michael@0:   // milestone elements. This is because any timed element with dependents and
michael@0:   // with significant transitions yet to fire should have their next milestone
michael@0:   // registered. Other timed elements don't matter.
michael@0:   const MilestoneEntry* p = mMilestoneEntries.Elements();
michael@0: #if DEBUG
michael@0:   uint32_t queueLength = mMilestoneEntries.Length();
michael@0: #endif
michael@0:   while (p < mMilestoneEntries.Elements() + mMilestoneEntries.Length()) {
michael@0:     mozilla::dom::SVGAnimationElement* elem = p->mTimebase.get();
michael@0:     elem->TimedElement().HandleContainerTimeChange();
michael@0:     NS_ABORT_IF_FALSE(queueLength == mMilestoneEntries.Length(),
michael@0:         "Call to HandleContainerTimeChange resulted in a change to the "
michael@0:         "queue of milestones");
michael@0:     ++p;
michael@0:   }
michael@0: }